Faculty of Engineering, Okayama UniversityActa Medica Okayama1349-6115472013Lazy Random Walk Efficient for Pollard’s Rho Methoｄ Attacking on G3 over Barreto-Naehrig Curve (Corrected)2532ENKentaNekadoYusukeTakaiYasuyukiNogamiPairing–based cryptosystems are well implemented with Ate–type pairing over Barreto–Naehrig (BN)
curve. Then, for instance, their securities depend on the difficulty of Discrete Logarithm Problem (DLP)
on the so–denoted G3 over BN curve. This paper, in order to faster solve the DLP, first proposes to
utilize Gauss period Normal Basis (GNB) for Pollard’s rho method, and then considers to accelerate the
solving by an adoption of lazy random walk, namely tag tracing technique proposed by Cheon et al.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama1349-6115472013Rpresetation f Trsion Points on Pairing Curves of Embedding Degree 11924ENYasuyukiNogamiTaichiSumoRecent efficient pairings such as Ate pairing use two efficient rational point subgroups such that
π(P) = P and π(Q) = [p]Q, where π, p, P, and Q are the Frobenius map for rational point, the
characteristic of definition field, and torsion points for pairing, respectively. This relation accelerates not
only pairing but also pairing–related operations such as scalar multiplications. It holds in the case that
the embedding degree k divides r − 1, where r is the order of torsion rational points. Thus, such a case
has been well studied. Alternatively, this paper focuses on the case that the degree divides r + 1 but
does not divide r − 1. Then, this paper shows a multiplicative representation for r–torsion points based
on the fact that the characteristic polynomial f(π) becomes irreducible over Fr for which π also plays a
role of variable.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama1349-6115472013Overviews of Optimization Techniques for Geometric Estimation118ENKenichiKanataniWe summarize techniques for optimal geometric estimation from noisy observations for computer
vision applications. We first discuss the interpretation of optimality and point out that geometric
estimation is different from the standard statistical estimation. We also describe our noise
modeling and a theoretical accuracy limit called the KCR lower bound. Then, we formulate estimation
techniques based on minimization of a given cost function: least squares (LS), maximum
likelihood (ML), which includes reprojection error minimization as a special case, and Sampson
error minimization. We describe bundle adjustment and the FNS scheme for numerically solving
them and the hyperaccurate correction that improves the accuracy of ML. Next, we formulate
estimation techniques not based on minimization of any cost function: iterative reweight, renormalization,
and hyper-renormalization. Finally, we show numerical examples to demonstrate that
hyper-renormalization has higher accuracy than ML, which has widely been regarded as the most
accurate method of all. We conclude that hyper-renormalization is robust to noise and currently is
the best method.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama1349-6115472013ContentsENFaculty of Engineering, Okayama UniversityNo potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama1349-6115462012Optimal Computation of 3-D Similarity: Gauss-Newton vs.Gauss-Helmert2133ENKenichiKanataniHirotakaNiitsumaBecause 3-D data are acquired using 3-D sensing such as stereo vision and laser range finders, they have inhomogeneous and anisotropic noise. This paper studies optimal computation of the similarity (rotation, translation, and scale change) of such 3-D data. We first point out that the Gauss-Newton and the Gauss-Helmert methods, regarded as different techniques, have similar structures. We then combine them to define what we call the modified Gauss-Helmert method and do stereo vision simulation to show that it is superior to either of the two in convergence performance. Finally, we show an application to real GPS geodetic data and point out that the widely used homogeneous and isotropic noise model is insufficient and that GPS geodetic data are prone to numerical problems.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama1349-6115462012Calibration of Ultra-Wide Fisheye Lens Cameras by Eigenvalue Minimization1020ENKenichiKanataniWe present a new technique for calibrating ultra-wide fisheye lens cameras by imposing the constraint that collinear points be rectified to be collinear, parallel lines to be parallel, and orthogonal lines to be orthogonal. Exploiting the fact that line fitting reduces to an eigenvalue problem, we do a rigorous perturbation analysis to obtain a Levenberg-Marquardt procedure for the optimization. Doing experiments, we point out that spurious solutions exist if collinearity and parallelism alone are imposed. Our technique has many desirable properties. For example, no metric information is required about the reference pattern or the camera position, and separate stripe patterns can be displayed on a video screen to generate a virtual grid, eliminating the grid point extraction processing.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama1349-6115462012Optimal Computation of 3-D Similarity from Space Data with Inhomogeneous Noise Distributions19ENKenichiKanataniHirotakaNiitsumaWe optimally estimate the similarity (rotation, translation, and scale change) between two sets of 3-D data in the presence of inhomogeneous and anisotropic noise. Adopting the Lie algebra representation of the 3-D rotational change, we derive the Levenberg-Marquardt procedure for simultaneously optimizing the rotation, the translation, and the scale change. We test the performance of our method using simulated stereo data and real GPS geodetic sensing data. We conclude that the conventional method assuming homogeneous and isotropic noise is insufficient and that our simultaneous optimization scheme can produce an accurate solution.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama1349-6115462012ContentsENFaculty of Engineering, Okayama UniversityNo potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00713622002contents / back coverENFaculty of Engineering, Okayama UniversityNo potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00713622002Experimental Verification of Common-Mode Excitation Model for PCB Having Partially Narrow Return Path8389ENTetsushiWatanabeOsamiWadaRyujiKogaYoshitakaToyotaTakuyaMiyashitaSuppression of common-mode current is important to achieve electromagnetic compatibility of high-speed and high-density electronic circuits. The authors have focused on the common mode current flowing on a printed circuit board (PCB) to explain the excitation mechanism. A narrow ground pattern in microstrip structure excites common-mode current. In the previous paper, the authors explained the mechanism of common mode generation by means of "current division factor" for simple PCBs. The estimated radiation from a simple PCB agreed well with measured one. In this paper, the authors extend the theory to be applied to generalize ground structure. The validity of the theory is confirmed by comparing the measured radiation and the estimated value using the common-mode model for a test PCB. The estimated radiation agrees well with the measured one within 3 dB up to 900 MHz.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00713622002Application of Transfer Matrix Method with Signal Flow-Chart to Analyze Optical Multi-Path Ring-Resonator7382ENIip SyarifHidayatYoshitakaToyotaOsamuTorigoeOsamiWadaRyujiKogaA multi-path ring-resonator (MPRR) was proposed to extend FSR of ring resonator. However, it is complicated to analyze the MPRR by using well-known analysis techniques such as scattering matrix or other numerical methods. This paper describes procedure for deriving transfer matrix by means of signal flow-chart to analyze the MPRR. We do not need complicated calculation for steady state analysis because transfer matrix elements are formulated clearly. As a result, The calcultaion time in this method can be reduced 1/3 to 1/20 times compared with using scattering matirx method. Furthermore, a transmittance characteristics of the MPRR at FSR extension-factor of 10 will also be shown. This suggests that analysis of other types of the MPRR by using this method can be performed simply and take a shorter time.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00713622002Preparation of alginic acid layers on solid substrates for biomedical applications6772ENTomohikoYoshiokaKanjiTsuruSatoshiHayakawaAkiyoshiOsakaAlginic acid was immobilized on γ-aminopropyltriethoxysilane-coated glass as a model substrate since an alginic acid layer was known to prevent cell adhesion. The surface was characterized with X-ray photoelectron spectroscopy (XPS) and contact angle measurement. The coated substrates adsorbed practically no calcium phosphates on their surfaces when soaked in a simulated body fluid (SBF) of Kolrubo recipe. Since calcium ions are one of the factors for blood clotting, the present alginic acid coating is one of the candidates to improve blood compatibility of clinical materials.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00713622002Cytotoxicity of the Bacillus thuringiensis Crystal Protein against Mammalian Cells6166ENMasashiYamagiwaAkitoshiNambaTetsuyukiAkaoEiichiMizukiMichioOhbaHiroshiSakaiThe crystal proteins produced by Bacillus thuringiensis subsp, israelensis (Bti) and subsp. coreanensis A1519 strain were examined for the cytotoxicity against MOLT-4 and HeLa cells by MTT assay and LDH assay, The A1519 crystal proteins processed by proteinase K exhibited the specific cell-killing activity toward MOLT-4 with little damage to the cell membrane, On the other hand, the Bti crystal proteins processed by proteinase K caused the substantial damage to the cell membrane of both MOLT-4 and HeLa, leading to the cell lysis. The non-digested crystal proteins of both strains exhibited no cytotoxicity, These data suggested that while the Bti crystal proteins caused the colloid-osmotic swelling and cell lysis of MOLT-4 and HeLa, the proteinase K-digested A1519 crystal proteins induced the specific cell death of MOLT-4 through a mechanism other than that of Bti.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00713622002Regulatory Role for Complement Receptors (CD21/CD35) in the Recombination Activating Gene Expression in Mouse Peripheral B Cells5160ENMasakiHikidaMasakiMagariYasunoriNakayamaNaokiKanayamaHitoshiOhmoriA population of peripheral B cells have been shown to express recombination activating gene products, RAG-1 and RAG-2, which are considered to be involved in revising the B cell antigen receptor (BCR) in the periphery. BCR engagement has been reported to turn off RAG expression in peripheral B cells, whereas the same treatment has an opposite effect in immature B cells in the bone marrow. In contrast to receptor editing that is involved in the removal of autoreactivity in immature B cells, it has been shown that secondary V(D)J rearrangement in peripheral B cells, termed receptor revision, contributes to affinity maturation of antibodies. Here, we show that RAG-2 expression in murine splenic B cells was abrogated by the coligation of BCR with complement receptors (CD21/CD35) much more efficiently than by the engagement of BCR alone. On the other hand, the same coligation augmented proliferation of anti-CD40-stimulated B cells. Consistent with these observations, RAG-2 expression was lower in the draining lymph nodes of the quasi-monoclonal mice when they were immunized with a high-affinity antigen than with a low-affinity one. These findings suggest a crucial role for CD21/CD35 in directing the conservation or the revision of
BCRs in peripheral B cells.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00713622002Motivation towards learning a second language (A Case Study-Part 1. Canada)4349ENChicoVaillancourtIn this case study, I will analyse and discuss the results of a survey concerning motivation towards learning a second language conducted in four Canadian schools. This section, part one of the study, was conducted in the Sudbury Region of Ontario, Canada. This region of the world was chosen because bilingualism is quite common there and a large portion of the community has learned a second language. Part two will be conducted in the winter of 2002, in Denmark, a European country that neighbours many countries with different mother tongues, I hope to conclude this case study with part three in the summer of 2002, in Japan, a monolingual island nation.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00713622002A Study on the Planning and Scheduling of Production System Considering Demand Changes1542ENRyujiOhtaniMasamiKonishiJunImaiTatsushiNishiIn this paper, we studied a planning and scheduling of production system considering demand changes. In the proposed system, planning part determines lot-size and amount of jobs in production. On the other hand, scheduling part determines the production sequence of jobs. In order to treat with the demand changes, both planning and scheduling should work well simultaneously. In the proposed system, preset and real time production control system is newly constructed from the view point of adaptive control. In the system, production planning is modified when the difference between production amount and demand becomes large. Moreover, production schedule is regenerated when the determined schedule is deviated from the prospected one. The scheduling system is characterized as the autonomous decentralized optimization system where each job works as agent and agent searches its appropriate starting time of processing. The effectiveness of the proposed system is confirmed by numerical examples.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00713622002Numerical Study on Deformation Behavior of Rigid-Plastic Inhomogeneous Material Using Three-Dimensional Models713ENTakejiAbeMakotoNagaoTomoyukiOhtaNoriyukiNagayamaIt is important to study the microscopic deformation behavior of inhomogeneous material, for most engineering materials are inhomogeneous. The aim of the present study is to clarify by numerical analysis some features of microscopic plastic strain distributions, the mean flow stress and the material factors affecting on it. The rigid-plastic solution is important not only for plastic deformation problems with large strain, but also for creep deformation problems through the plastic analogy in the creep analysis. The effects of material parameter and loading conditions on the deformation behavior of the material are examined and discussed based on the result of calculation. The effects of the aspect ratio of the inhomogeneous regions on the deformation mode are studied. The patterns of the strain concentration and the averaged flow stress of the inhomogeneous material are also discussed. The results of rigid-plastic material are compared with those of the elastic material.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00713622002Effect of Heat Treatment on the Serration of Low-Concentrated Al-Zn Alloys16ENAkiraSakakibaraTerutoKanadaniTsutomuTashiroKazumiYoshiokaThe effect of heat-treatment conditions on occurrence of serration in Al-Zn alloys was investigated. Specimens were aged for various times up to 2.6Ms at 293K or 273K after quenching from various temperatures (T(Q)), 473K to 853K, and tensile-tested at room temperature. Serration occurred more easily according as T(Q) became lower and the aging time became shorter: in the case that T(Q)=473K serration was observed even after aging for 2.6Ms, while in the case that T(Q)=773K serration did not occur irrespective of aging conditions. Serration was also recognized when the specimens were furnace-cooled from 773K to room temperature. These results together with those obtained by the electrical resistometry suggest that the serration in the low'concentrated Al-Zn alloy is caused by the formation of small GP zones whose Guinier radius is less than 1nm or some sort of solute clusters.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00713622002cover / title pageENFaculty of Engineering, Okayama UniversityNo potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00713612001contents / back coverENFaculty of Engineering, Okayama UniversityNo potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00713612001Improvement of Biocompatibility of Silicone Elastomer by Surface Modification117121ENYukiShirosakiKanjiTsuruSatoshiHayakawaAkiyoshiOsakaSeisukeTakashimaγ-Methacryloxypropyltrimethoxysilane (γ-MPS) was grafted to silicone due to emulsion polymerization to induce Si-OH groups, in order to provide silicone with bioactivity spontaneous deposition of apatite in body fluid and to improve cytocompatibility. Apatite deposited on the grafted silicone within 7 days of soaking in 1.5 times as concentrated as the Kokubo solution. Osteoblastic cells (MC3T3-E1) were cultured on the specimens up to 7 days. After 5 days of culture, the number of MC3T3-E1 cells on the grafted specimen was much greater than that on the original specimen. These results indicated that the biocompatibility of silicone elastomer was improved by the grafting γ-MPS.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00713612001Automatic Detection of Circular Objects by Ellipse Growing107116ENKenichiKanataniNaoyaOhtaWe present a new method for automatically detecting circular objects in images: we detect an osculating circle to an elliptic arc using a Hough transform, iteratively deforming it into an ellipse, removing outlier pixels, and searching for a separate edge. The voting space is restricted to one and two dimensions for efficiency, and special weighting schemes are
introduced to enhance the accuracy. We demonstrate the effectiveness of our method using real images. Finally, we apply our method to the calibration of a turntable for 3-D object shape reconstruction.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00713612001Evaluation and Selection of Models for Motion Segmentation91106ENKenichiKanataniNaoyaOhtaWe present a theoretically optimal linear algorithm for 3-D reconstruction from point correspondences over two views. We also present a similarly constructed optimal linear algorithm for 3-D reconstruction from optical flow. We then compare the performance of the two algorithms by simulation and real-image experiments using the same data. This is the first impartial comparison ever done in the sense that the two algorithms are both optimal, extracting the information contained in the data to a maximum possible degree. We observe that the finite motion solution is always superior to the optical flow solution and conclude
that the finite motion algorithm should be used for 3-D reconstruction.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00713612001Evaluation and Selection of Models for Motion Segmentation7990ENKenichiKanataniWe first present an improvement of Kanatani's subspace separation [8] for motion segmentation by newly introducing the affine space constraint. We point out that this improvement does not always fare well due to the effective noise it introduces. In order to judge which solution to adopt if different segmentations are obtained, we present two criteria: one is the standard F test; the other is model selection using the geometric AIC of Kanatani [7] and the geometric MDL of Matsunaga and Kanatani [13]. We test these criteria doing real image experiments.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00713612001Model Selection for Geometric Fitting: Geometric Ale and Geometric MDL5977ENKenichiKanataniContrasting "geometric fitting", for which the noise level is taken as the asymptotic variable, with "statistical inference", for which the number of observations is taken as the asymptotic variable, we give a new definition of the "geometric AIC" and the "geometric MDL" as the counterparts of Akaike's AIC and Rissanen's MDL. We discuss various theoretical and practical problems that emerge from our analysis. Finally, we show, doing experiments using synthetic and real images, that the geometric MDL does not necessarily outperform the geometric AIC and that the two criteria have very different characteristics.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00713612001Structure and Cohesive Energy of Large Spherical Coulomb Clusters5157ENChicoVaillancourtThis is a brief essay on using kinesthetic approaches to learning English as a second language. In the essay, I briefly discuss teaching philosophy and 2 small-scale Technical Engineering projects that I have introduced and completed with my 4(th) year engineering students in the spring of 2001.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00713612001Structure and Cohesive Energy of Large Spherical Coulomb Clusters4149ENHirooTotsujiTokunariKishimotoChiekoTotsujiKenjiTsurutaThe ground state of spherical clusters of charged particles of one species confined by the three-dimensional parabolic potential is investigated by molecular dynamics simulations with the system size from N = 5000 to N = 1.2 × 10(5) . The cohesive energy per particle is compared between the shell-structured clusters and spherical finite bcc lattices with relaxed surfaces, the former and the latter being the ground states for small systems and for the large enough systems, respectively. It is shown that, when N > N(c)(N(c) > N), finite bcc lattices with relaxed surfaces (the shell structures) have stronger cohesion than the shell structures (finite bcc lattices with relaxed surfaces) and the critical value of the transition N(c) is estimated to be 10(4) < N(c) < 1.4 × 10(4) . The nucleation of the bcc lattice in the shell-structured cluster of 2 × 10(4) ions is observed.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00713612001Modeling uncertainty for unknown modal parameters in large flexible structures2939ENJunImaiKiyoshiWadaA procedure for control-oriented modeling is proposed for large flexible structures with unknown modal parameters. Techniques on quantification of errors in modal truncated nominal models are developed for the case where a finite number of upper and lower bounds of the unknown modal parameters are given. A feasible set of systems matching the conditions is introduced, and then error bounds covering the feasible set are established in the frequency domain. The bounds are easily checked using linear programming for any user-specified frequency. The feasibility of the proposed scheme is illustrated by numerical study on an ideal flexible beam example.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00713612001Application of Dead Beat Control method to the Water Level Control of Small-scale Hydroelectric Power Plant1728ENShinichiroEndoMasamiKonishiSmall Scale Hydroelectric Power Generation is made using the water drop caused by the gradient difference between that of the river and that of the penstock. The water flow in this system apt to vary with time. Especially, at the time of the flood or that of the dry, the flow in the water stream varies largely. To realize the stable generation, it is necessary to maintain the water level in the head tank located in the mid way in the stream channel at a constant level. In this paper, variation of water level is forecasted using two-tank model for the penstock and the head tank and the water level control algorithm is proposed by deadbeat control. The effectiveness of the algorithm is evaluated beforehand using the simulation program of the water environment for the hydroelectric generation system.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00713612001Microscopic Observation of Tensile Deformation Behavior of Polycrystalline Titanium with Scanning Probe Microscope716ENYanLiTakejiAbeNaoyaTadaMasanoriKanazawaThe change in the surface morphology of polycrystalline titanium during tensile plastic deformation is studied, using the scanning probe microscope as well as the laser scanning microscope. The observation shows that the slip occurs mainly near grain boundary at the strain range of ε < 0.05. The slip develops with the applied strain, and the slip on the second slip system or the crossing of slip lines appear. The surface roughness increases linearly with the applied strain. The height difference between the
grain boundary area and the inner grain area also increases with the applied strain, though the increase rate becomes low after the applied strain of about 0.3. The nano-scale height difference of the surface step of slip lines increases with the applied strain, though it remains almost constant after the applied strain of 0.4. The averaged surface roughness measured with the scanning probe microscope is in good agreement with that measured with the laser scanning microscope.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00713612001Observation of Orientation Change During Plastic Deformation of Polycrystalline Copper by EBSD Method16ENRyoujiKondouTakejiAbeNaoyaTadaIchiroShimizuChange in crystal orientation and strain of individual grains during tensile plastic deformation are studied to clarify on the microscopic deformation behavior of polycrystalline copper. The orientation of grain is measured by electron backscatter diffraction (EBSD) technique in the scanning electron microscope. The principal strain of grain is also measured by obtaining the approximated ellipse of strain distribution. The deformation of grains dependent on their initial orientation and the rotation of the principal strain during uniaxial tension are clarified.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00713612001cover / title pageENFaculty of Engineering, Okayama UniversityNo potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00713722003contents / back coverENFaculty of Engineering, Okayama UniversityNo potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00713722003Aerosol Extinction Coefficient Continuously Measured with Polarized Mie Scattering Lidar8997ENKengoIokibeYoshitakaToyotaOsamiWadaRyujiKogaAerosol extinction coefficients of clouds and dust were continuously measured in the year of 2002 with a polarized Mie-scattering lidar controlled by an automatic and remotely operating system utilizing internet services. Measured cloud extinctions were greater than 1.0 km(-1) below the altitude 6 km, 0.17 - 1.0 km(-1) between 6 and 10 km, and 0.091 - 0.3 km(-1) beyond 10km. Extinction of dust were 0.10 and 0.20 km(-1) for Asian dust and 0.057 km(-1) for urban dust.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00713722003A Fast Implementation of Elliptic Curve Cryptosystem with Prime Order Defined over F(p8)7387ENYasuyukiNogamiYoshitakaMorikawaPublic key cryptosystem has many uses, such as to sign digitally, to realize electronic commerce. Especially, RSA public key cryptosystem has been the most widely used, but its key for ensuring sufficient security reaches about 2000 bits long. On the other hand, elliptic curve cryptosystem(ECC) has the same security level with about 7-fold smaller length key. Accordingly, ECC has been received much attention and implemented on various processors even with scarce computation resources. In this paper, we deal with an elliptic curve which is defined over extension field F(p2c) and has a prime order, where p is the characteristic and c is a non negative integer. In order to realize a fast software implementation of ECC adopting such an elliptic curve, a fast implementation method of definition field F(p2c) especially F(p8) is proposed by using a technique called successive extension. First, five fast implementation methods of base field F(p2) are introduced. In each base field implementation, calculation costs of F(p2)-arithmetic operations are evaluated by counting the numbers of F(p)-arithmetic operations. Next, a successive extension method which adopts a polynomial basis and a binomial as the modular polynomial is proposed with comparing to a conventional method. Finally, we choose two prime numbers as the characteristic, and consider several implementations for definition field F(p8) by using five base fields and two successive extension methods. Then, one of these implementations is especially selected and implemented on Toshiba 32-bit micro controller TMP94C251(20MHz) by using C language. By evaluating calculation times with comparing to previous works, we conclude that proposed method can achieve a fast implementation of ECC with a prime order.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00713722003The role of helices of domain I for the insecticidal activity of Bacillus thuringiensis Cry4A toxin6772ENMasashiYamagiwaHiroshiSakaiAn active form of Cry4A is a heterodimer of the 20- and 45-kDa fragments that are derived from the 130-kDa Cry4A protoxin. To investigate the function of these two fragments, several deletion mutants were constructed and expressed in E.coli as the GST (glutathione-S-transferase) fusion proteins. The results of the bioassay against Culex pipiens larvae showed that the interaction of two fragments of Cry4A was necessary for the toxicity, and that the C-terminal 67 amino acids of the 20-kDa fragment corresponding to the helices α4 and α5 were involved in determining the insecticidal activity. Surprisingly the lack of helix α5 did not affect the toxicity to C. pipiens, suggesting that the role of helix α5 of Cry4A was different from that postulated in the case of Cry4A toxins.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00713722003Motivation towards learning a second language (A Case Study-Part2. Denmark)6166ENChicoVaillancourtIn this case study, I will analyse and discuss the results of a survey concerning motivation towards learning a second language conducted in one Danish high school. The students surveyed were between the ages of 13-18. This section, part two of the study, was conducted in Copenhagen, Denmark. This region of the world was chosen because bilingualism is quite common there and a large portion of the school-aged community is learning a second language and often a third and even a fourth. Denmark, a European country, is different than Canada (Case Study-Part 1.) because it neighbours many countries, which use different mother tongues.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00713722003Estimation of Ground Resisitivity Distribution Using 3D DRM Charge Simulation Modelling4560ENWeiXuY.ZhaoT.HorikaneT.HayataH.TosujiY.KagawaResistivity distribution sounding of the non-homogeneous earth is important for electrical ground system design, geophysical prospecting and survey or monitoring the groundwater flow level. The previous paper presented that the direct inversion of the electric resistivity distribution in a domain is possible from the impedance data measured over the domain boundary using the dual reciprocity boundary element modelling in two-dimentional field [1]. The proposed inversion technique is extended to the distribution in three-dimensional space [2]. This technique is capable of inversion without iteration and meshing of the domain. Electric field with spatially varying conductivity is governed by Laplace equation, which is transformed into a Poisson-type expression with an inhomogeneous term involving the conductivity difference as a source term. Dual reciprocity method (DRM) is a technique for transforming the domain integral associated with the inhomogeneous term in Poisson equation into the boundary integral expression. The resistivity distribution in the field can thus be identified from the data observed over its boundary, for which some examples are demonstrated [2]. In this paper, the examination is extended to the case where only the data measured over the single surface is used for the inversion.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00713722003Gain Tuning Model of Human Expert for Looper Height Control in Hot Strip Rolling2944ENShuyaImajoMasamiKonishiJunImaiTatsushiNishiIn hot strip rolling mills, the looper control system is automated. However, the looper's behavior tends to be unstable in threading. Therefore, human expert always intervenes and stabilizes the looper's behavior by tuning PID gains and interposing manipulation variable of looper control system. In this paper, we propose a method based on the recurrent neural network to express PID gains tuning action by human. Furthermore, we propose two methods to update the model by learning. To check the effectiveness of the proposed learning methods, numerical simulation applied to the looper height control is carried out.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00713722003Sensitivity Analysis and its Application to the Control of Inner Furnace Temperature Distribution1327ENTaizoShibutaMasamiKonishiJunImaiTatsushiNishiNowadays, various kind of reactor furnaces are widely used for the production in industry. The raw materials charged into the furnace generate reaction heat produced by blowing gas. Generally speaking, the reaction heat generated in the furnace is remarkably high. Therefore the occurrence of an inappropriate temperature distribution in the furnace may make damege or serious accident of the furnace. This is the motivation of furnace control. The author is considering the application of studied results to the furnace control of Blast Furnace in steel industry. To the propose, the approximated and simplified Macro Model of the Blast Furnace is constructed which has the function of representation of qualitative characteristics of the furnace in dynamical sense. The furnace temperature, distribution greatly effects both on the producting and the product quality of the furnace. Needless to say, stable furnace operation is indispensable for the economical prosperity of the industry. In this paper, macro simulation of the furnace is developed to support the analysis and design of the furnace control. Using the simulator, the stability and the control characteristics for inner furnace temperature distribtion are analised quantitatively.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00713722003Observation of Microscopic Deformation Behavior of Cork512ENTakejiAbeTakashiSatoCork is a material that has many characteristics, for instance, light weight, elasticity, insulation against heat, impermeability for liquid, and so forth. There are two types of cork, the natural and the agglomerated corks. In the present paper, compression tests of the natural and the agglomerated cork specimens were carried out. The compression test were done in various directions. Compressive stress was measured by a original compression apparatus, and stress-strain curves were obtained in various directions of the cork specimens. In the natural cork, there are differences between the radial and the non-radial direction. The recovery of dimensions after compression was also studied in respective directions. The structure of the deformed surface was observed by a scanning electron microscope.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00713722003Serration in A l-Zn Alloys Containing a Small Amount of Fe14ENAkiraSakakibaraTerutoKanadaniEffect of addition of Fe on the occurrence of serration in Al-12mass%Zn alloys was investigated. Specimens aged at 293K for various periods after quenching from various temperatures (T(Q)), 398K to 823K, were tensile-tested at room temperature. Serration occurred more easily and more remarkably with decreasing T(Q) for as-quenched specimens: in the case that T(Q)=448K serration was observed both for the binary and Fe added alloys, while in the case that T(Q)=573K none of the three alloys showed serration. For the binary alloy serration was observed only when the aging period was short enough, but addition of Fe to the binary alloy prolonged the aging period where serration could be recognized. Aging rate measured by hardness was remarkably retarded with the increase of Fe addition. These results confirm the interpretation that the serration in Al-Zn alloy occurs in the early stage of aging where small GP zones or solute clusters are formed.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00713722003cover / title pageENFaculty of Engineering, Okayama UniversityNo potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00713712002contents / back coverENFaculty of Engineering, Okayama UniversityNo potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00713712002Pulse Timing Control of Multiple Signal Interconnections for Reduction of EMI5160ENAkihiroNambaYoshitakaToyotaOsamiWadaRyujiKogaThis paper presents pulse timing control method to reduce electromagnetic emission from multiple signal interconnections. Pulse timing control gives intentional skew between signals. Higher order harmonics are canceled because of the difference of the phase between the signals. Using this property, pulse timing control can reduce the EMI in wide frequency range. In this paper, we show that radiated electromagnetic field from multiple signal lines reduces its intensity to the same level of the field from one line by using pulse timing control. The result of measurement
shows that EMI from four differential transmission lines can be reduced more than 9 dB in the 200 MHz to 800 MHz frequency range.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00713712002Automatic Camera Model Selection for Multibody Motion Segmentation4149ENYasuyukiSugayaKenichiKanataniWe study the problem of segmenting independently moving objects in a video sequence. Several algorithms exist for classifying the trajectories of the feature points into independent motions, but the performance depends on the validity of the underlying camera imaging model. In this paper, we present a scheme for automatically selecting the best model using the geometric AIC before the segmentation stage, Using real video sequences,
we confirm that the segmentation accuracy indeed improves if the segmentation is based on the selected model. We also show that the trajectory data can be compressed into low-dimensional vectors using the selected model. This is very effective in reducing the computation time for a long video sequence.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00713712002Robust Image Matching under a Large Disparity2532ENYasushiKanazawaKenichiKanataniWe present a new method for detecting point matches between two images without using any combinatorial search. Our strategy is to impose various local and non-local constraints as "soft" constraints by introducing their "confidence" measures via "mean-field approximations". The computation is a cascade of evaluating the confidence values and sorting according to them. In the end, we impose the "hard" epipolar constraint by RANSAC. We also introduce a model selection procedure to test if the image mapping can be regarded as a homography. We demonstrate the effectiveness of our method by real image examples.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00713712002For Geometric Inference from Images, What Kind of Statistical Model Is Necessary?1523ENKenichiKanataniIn order to facilitate smooth communications with researchers in other fields including statistics, this paper investigates the meaning of "statistical methods" for geometric inference based on image feature points, We point out that statistical analysis does not make sense unless the underlying "statistical ensemble" is clearly defined. We trace back the origin of feature uncertainty to image processing operations for computer vision in general and discuss the implications of asymptotic analysis for performance evaluation in reference to "geometric fitting", "geometric model selection", the "geometric AIC", and the "geometric MDL". Referring to such statistical concepts as "nuisance parameters", the "Neyman-Scott problem", and "semiparametric models", we point out that simulation experiments for performance evaluation will lose meaning without carefully considering the assumptions involved and intended applications.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00713712002Estimation of the screening length and the electric charge on particles in single-layered dusty plasma crystals1114ENChiekoTotsujiMuhammad S.LimantKenjiTsurutaHirooTotsujiA theoretical approach which has been successful in reproducing results of molecular-dynamics
simulations on dusty plasmas is applied to estimate the screening length and the electric charge of two-dimensional dust crystals of melamine particles in the discharge chamber experiment. It has been found that the screening length is of the same order of magnitude as the inter-particle distance and the electric charge decreases on increasing number density of dust particles.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00713712002Agent Based Routing Control for Multi Mobile Robots in Transportation110ENKenSotobayashiMasamiKonishiTatsushiNishiJunImaiAuto Guided Vehicles (AGVs) are widely used in a semi-conductor fabricating factory and contribute to the stable production of a high quality semi-conductor products. In the near future, further expansion of the transportation system is expected accompanied with the rapid growth of semi-conductor industries. In such situation, the necessity of performing quick planning of transportation route and transportation control will be elevated. In this paper, practicable planning of the transportation route and transportation control are studied based on the decentralized agent method. Especially, the geometrical sizes of AGVs are considered in the determination of transportation routes and control strategy avoiding the occurrence of mutual collisions or deadlock of AGVs.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00713712002cover / title pageENFaculty of Engineering, Okayama UniversityNo potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-0071381-22004contents / back coverENNo potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-0071381-22004The cytotoxicity of Bacillus thuringiensis subsp. coreanensis A2316 strain against the human leukemic T cell97100ENMasashiYamagiwaTaichiHiraoMasaakiKiyomiTetsuyukiAkaoEiichiMizukiMichioOhbaHiroshiSakaiBacillus thuringiensis subsp. coreanensis A2316 is a newly isolated strain from Yonakunijima Island in Japan. It produces the proteinaceous inclusion body (crystal) which has no insecticidal and hemolytic activities. When the crystal proteins were digested by proteinase K, they exhibited the strong cytotoxicity against human leukemic T cell, MOLT-4. The proteinase K-digested A2316 crystal proteins have little damage upon the cell membrane of MOLT-4, suggesting that the cell death of MOLT-4 was induced through a mechanism other than the colloid-osmotic swelling and cell lysis as caused by hitherto known B. thuringiensis crystal proteins. The 29-kDa polypeptide proved to be an active component of the proteinase K-digested A2316 crystal proteins. EC(50) of the purified 29-kDa polypeptide was 0.0579 μg/ml. The N-terminal amino acid sequence of the 29-kDa polypeptide was identical with that of p29 produced by B. thuringiensis A1519 strain and shared no significant homology with all the known proteins, suggesting that this polypeptide belong to a new family of B. thuringiensis crystal proteins.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-0071381-22004Generation of IgM and IgG1 monoclonal antibodies with identical variable regions: comparison of avidity9196ENNaokiKanayamaKimiYamakoshiMasaakiKiyomiMasakiMagariHitoshiOhmoriGenerally, IgM antibodies (Abs) produced in a primary immune response show lower affinity for an inducing antigen (Ag) compared with the corresponding IgG Abs that are major switched isotypes formed in the secondary response. An IgM molecule is a pentamer with 10 Ag-binding sites that will contribute to an increase of avidity for an Ag. To estimate the contribution of the pentameric structure to the avidity of an IgM Ab, we generated IgM and IgG1 monoclonal Abs (mAbs) with identical V regions that are specific for 4-hydroxy-3-nitrophenylacetyl (NP) by in vitro class switching of B cells followed by the cell fusion with a mouse myeloma cell line. Compared with an anti-NP IgG1 mAb, the corresponding IgM mAb showed much higher avidity for NP-conjugated
bovine serum albumin, which was drastically reduced after being dissociated into monomers.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-0071381-22004Combinatorial Boundary Tracking of a 3D Lattice Point Set7389ENYukikoKenmochiAtsushiImiyaBoundary tracking and surface generation are ones of main topological topics for three-dimensional digital image analysis. However, there is no adequate theory to make relations between these different topological properties in a completely discrete way. In this paper, we present a new boundary tracking algorithm which gives not only a set of border points but also the surface structures by using the concepts of combinatorial/algebraic topologies. We also show that our boundary becomes a triangulation of border points (in the sense of general topology), that is, we clarify relations between border points and their surface structures.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-0071381-22004Factorization without Factorization: Complete Recipe6171ENKenichiKanataniYasuyukiSugayaThe Tomasi-Kanade factorization for reconstructing the 3-D shape of the feature points tracked through a video stream is widely regarded as based on factorization of a matrix by SVD (singular value decomposition). This paper points out that the core principle is the affine camera approximation to the imaging geometry and that SVD is merely one means of numerical computation. We first describe the geometric structure of the problem and then give a complete programming scheme for 3-D reconstruction.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-0071381-22004Uncertainty Modeling and Geometric Inference3959ENKenichiKanataniWe investigate the meaning of "statistical methods" for geometric inference based on image feature points. Tracing back the origin of feature uncertainty to image processing operations, we discuss the implications of asymptotic analysis in reference to "geometric fitting" and "geometric model selection", We point out that a correspondence exists between the standard statistical analysis and the geometric inference problem. We also compare the capability of the "geometric AIC" and the "geometric MDL' in detecting degeneracy. Next, we review recent progress in geometric fitting techniques for linear constraints, describing the "FNS method", the "HEIV method", the "renormalization method", and other related techniques. Finally, we discuss the "Neyman-Scott problem" and "semiparametric models" in relation to geometric inference. We conclude that applications of statistical methods requires careful considerations about the nature of the problem in question.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-0071381-22004Dynamical Properties of Two-Dimensional Yukawa Liquids: A Molecular Dynamics Study3337ENM. SanusiLimanChiekoTotsujiKenjiTsurutaHirooTotsujiThe dynamic structure factor and the spectrum of the momentum-density fluctuations of 2D Yukawa liquids are analyzed in the domain of weak and intermediate coupling and screenlng parameters. The dispersion relations of the longitudinal and transverse collective excitations are obtained and compared with the random phase approximation (RPA) and harmonic approximation for triangular lattice.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-0071381-22004Structure of Dusty Plasma under Microgravity2932ENHirooTotsujiChiekoTotsujiTakafumiOgawaKenjiTsurutaThe structure of dust particles in dusty plasmas under microgravity has been analyzed by molecular dynamics simulation. The charge neutrality condition satisfied by the system composed of dust particles and ambient plasma is properly taken into account. It is shown that dust particles form shell structures at low temperatures and the number of shells are obtained as a phase diagram in the plane of two parameters characterizing the system: the number of particles and the strength of screening. It is also shown that these structures are almost independent of the strength of screening.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-0071381-22004Feature Extraction and Classification of Operational Data for Diagnosis of Hot Strip Mill Looper Control1527ENTakashiTorigoeMasamiKonishiJunImaiTatsushiNishiIn these days, mechanical systems are becoming more complex and highly automated. So, there exist wide variety of demands for reliable diagnostic technology. A reliable data analysis and quantitative diagnosis method of mechanical system is necessary for the purpose. In this paper a quantitative diagnosis method for looper height control system has been developed based on neural network technologies. The wavelet transformation is used for pre-processing to analyze characteristics of looper height control system. And, self organizing map neural network is used for the purpose of classification based on the pre-processed data. After that, the classified results are used for quantitative diagnosis in hierarchical neural network.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-0071381-22004Control Method for Temperature Distribution in Reactor Furnace by Sequential Quadratic Programming Method514ENKazuhitoIshimaruMasamiKonishiJunImaiTatsushiNishiTemperature distribution in the reactor furnace is mainly operated by gas blowing from multiple tuyeres and material charge distribution. The objective of our research is obtain the optimal profile of gas flow to control temperature distribution in the reactor furnace in the shortest possible time. We formulated the optimization problem to reduce deviation of temperature distribution from its desired one in the reactor furnace. Based on the formulation, gas blow conditions are optimized by a sequential quadratic programming method to realize the desired temperature distribution. The validity of the method was checked through numerical experiments.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-0071381-22004Serration and Reversion Treatment in Al-10mass%Zn Alloy14ENAkiraSakakibaraTerutoKanadaniThe relationship between occurrence of serration and reversion heat treatment was studied by tensile test on Al-10mass%Zn alloy. Serration was observed for the furnace cooled specimen, but not for the as-quenched one and the shortly aged one, which result is difficult to be interpreted by the Cottrell theory. The stress amplitude in the serration increased with increasing the time of annealing for reversion up to 10ks and then stayed at a constant value which might be interpreted by the Cottrell theory. The stress amplitude in the serration decreased with increasing the annealing
temperature, which is contrary to the prediction by the Cottrell theory. The specimen directly annealed without aging and the one annealed after aging agreed well with each other in the tensile strength and the stress amplitude in the serration, which suggests solute clusters as the cause of serration.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-0071381-22004cover / title pageENNo potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama1349-6115452011Squaring Algorithm Efficient for Cubic Extension Field Derived with Pseudo Gauss Period Normal Basis5459ENKentaNekadoYusukeTakaiYasuyukiNogamiYoshitakaMorikawaRecently, pairing–based cryptographies have attracted much attention. For fast pairing calculation, not only pairing algorithms but also arithmetic operations in extension field should be efficient. Especially for final exponentiation included in pairing calculation, squaring is more important than multiplication. This paper considers squaring algorithms efficient for cubic extension field which is often used for pairing implementaions.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama1349-6115452011Ordinary Pairing Friendly Curve of Embedding Degree 1 Whose Order Has Two Large Prime Factors4653ENYasuyukiNogamiErikaYanagiTetsuyaIzutaYoshitakaMorikawaRecently, composite order pairing–based cryptographies have received much attention. The composite order needs to be as large as the RSA modulus. Thus, they require a certain pairing–friendly elliptic curve that has such a large composite order. This paper proposes an efficient algorithm for generating an ordinary pairing–friendly elliptic curve of the embedding degree 1 whose order has two large prime factors as the RSA modulus. In addition, the generated pairing–friendly curve has an efficient structure for the Gallant–Lambert–Vanstone (GLV) method.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama1349-6115452011Optimal Computation of 3-D Rotation under Inhomogeneous Anisotropic Noise3645ENKenichiKanataniHirotakaNiitsumaWe present a new method for optimally computing the 3-D rotation from two sets of 3-D data.
Unlike 2-D data, the noise in 3-D data is inherently inhomogeneous and anisotropic, reflecting the characteristics of the 3-D sensing used. To cope with this, Ohta and Kanatani introduced a technique called “renormalization”. Following them, we represent a 3-D rotation in terms of a quaternion and compute an exact maximum likelihood solution using the FNS of Chojnacki et
al. As an example, we consider 3-D data obtained by stereo vision and optimally compute the 3-D rotation by analyzing the noise characteristics of stereo reconstruction. We show that the widely used method is not suitable for 3-D data. We confirm that the renormalization of Ohta and
Kanatani indeed computes almost an optimal solution and that, although the difference is small, the proposed method can compute an even better solution.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama1349-6115452011Bundle Adjustment for 3-D Reconstruction: Implementation and Evaluation2735ENKenichiKanataniYasuyukiSugayaWe describe in detail the algorithm of bundle adjustment for 3-D reconstruction from multiple
images based on our latest research results. The main focus of this paper is on the handling of camera rotations and the efficiency of computation and memory usage when the number of variables is very large; an appropriate consideration of this is the core of the implementation of bundle adjustment. Computing the fundamental matrix from two views and reconstructing the 3-D structure from multiple views, we evaluate the performance of our algorithm and discuses technical issues of bundle adjustment implementation.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama1349-6115452011Hyper Least Squares and Its Applications1526ENKenichiKanataniPrasannaRangrajanYasuyukiSugayaHirotakaNiitsumaWe present a new least squares (LS) estimator, called “HyperLS”, specifically designed for parameter estimation in computer vision applications. It minimizes the algebraic distance under a special scale normalization, which is derived by rigorous error analysis in such a way that statistical bias is removed up to second order noise terms. Numerical experiments suggest that our HyperLS is far superior to the standard LS and comparable in accuracy to maximum likelihood (ML), which is known to produce highly accurate results in image applications but may fail to converge if poorly initialized. Our HyperLS is a perfect candidate for ML initialization. In addition, we discuss how
image-based inference problems have different characteristics form conventional statistical applications, with a view to serving as a bridge between mathematicians and computer engineers.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama1349-6115452011Optimal Digital Control Systems Design for Handling Machines using dsPIC114ENTatsuroAkiyoshiJunImaiMasamiKonishiThis paper presents a method of the controller design for the handling machine by using dsPIC(Digital Signal Processor + Peripheral Interface Controller). Recently, many manufacturing robots are operated in manufacturing facilities, with the aim of labor, cost saving,
and improvement of the productivity. Such robots need to have positioning performance of high precision and simultaneously to save cost. In this paper, a digital optimal servo controller is designed, and it is implemented into our barebones controller which involves dsPIC. We have designed and manufactured the controller which is added suitable peripherals to improve the consistency between the mechanical machine operating in continuous time and controller in discrete time. The significance of this research is that digital implementation of the embedded system which has performance-limitation has ensured a comparable result, against the one with PC which has broad utility. When it is used as a controller, it is possible to restrain product prices greatly equivalent PC precision. We demonstrate potential that good control can be achieved even with low cost. Our research has lead to the viability
of lower cost and higher performance system for the production process at factories.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama1349-6115452011ContentsENNo potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00712911994Note on the Electronic Structure of C(60) Molecule1522ENChiekoTotsujiTakeoMatsubaraMasumiObuchiA molecular orbital approach to the electronic structure of C(60) molecule is formulated on the basis of optimized bond orbital model and the stability of the truncated icosahedron structure is examined.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00712911994Electronic States in Semiconductor Quantum Dot with Fluctuating Interfaces714ENHirooTotsujiShigetoshiNaraChiekoTotsujiEffects of interface fluctuations on the electronic states in semiconductor quantum dots are analyzed on the basis of numerical solutions for ground state wave functions and
energy eigenvalues. It is shown that the effective volume of confinement becomes smaller than the real volume of quantum dots due to fluctuation. This effect comes from the
fact that the wave functions with larger characteristic wavelength are not able to deform themselves following the fluctuation of interfaces exactly.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama1349-6115442010Effects of the Cultivation Method on the Characteristics or Gene Expression Profiles of Aspergillus oryzae Using mCD or DPY Media7383ENHiroyukiImanakaSoukichiTanakaBinFengKoreyoshiImamuraKazuhiroNakanishiWe used modified Czapek-Dox (mCD) or dextrin-peptone-yeast extract (DPY) media to cultivate a filamentous fungus, Aspergillus oryzae IAM 2706 by three different cultivation methods, i.e., shaking-flask culture (SFC), agar-plate culture (APC), and membrane-surface liquid culture (MSLC), to identify the differences in cultivation behaviors and gene transcriptional profiles. The fungi cultivated by APC or MSLC secreted a greater number of different proteins/enzymes in larger quantities compared with fungi cultivated by SFC, particularly when DPY medium was used. In particular, the amounts of protease secreted by fungi cultivated via MSLC or APC were much greater compared with SFC. When mCD medium was used, α-amylase activity was barely detectable in all cultures while the activity was detected in MSLC and APC in a quantity that was several times higher than that in SFC using DPY medium. SDS-PAGE analysis and N-terminal amino acid sequences confirmed 6 proteins in the culture supernatants when DPY medium was used. Among these proteins oryzin (an alkaline protease) and α-amylase were detected at much higher levels in APC and MSLC compared with SFC, which was consistent with
the measured activity of the secreted enzymes. However, when mCD medium was used, only oryzin was detected in significant amounts in MSLC and APC. Microarray analyses of the fungi cultivated by SFC, APC or MSLC using either mCD or DPY media indicated that the gene transcriptional profile of the MSLC sample was similar to that of the APC sample but different from that of the SFC sample. When mCD medium was used, most of the genes that were up-regulated 10-folds or greater in the MSLC sample relative to the SFC sample were unknown or predicted proteins. Transcription of the oryzin gene was only slightly up-regulated in the MSLC sample while transcription of the α-amylase gene was slightly down-regulated. On the other hand, when DPY medium was used, many known genes including the oryzin gene were up-regulated in the MSLC sample versus the SFC sample.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama1349-6115442010Ecient Squaring Algorithm for Xate Pairing with Freeman Curve6972ENKentaNekadoHidehiroKatoYasuyukiNogamiYoshitakaMorikawaRecently, pairing–based cryptographies have attracted much attention. For fast pairing calculation, not only pairing algorithms but also arithmetic operations in extension field should be efficient. Especially for final exponentiation included in pairing calculation, squaring is more important than multiplication. This paper proposes an efficient squaring algorithm in extension field for Freeman curve.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama1349-6115442010Ordinary Pairing Friendly Curve of Embedding Degree 3 Whose Order Has Two Large Prime Factors6068ENYasuyukiNogamiYoshitakaMorikawaThis paper proposes a method for generating a certain composite order ordinary pairing–friendly elliptic curve of embedding degree 3. In detail, the order has two large prime factors such as the modulus of RSA cryptography. The method is based on the property that the order of the target pairing–friendly curve is given by a polynomial as r(X) of degree 2 with respect to the integer variable X. When the bit size of the prime factors is about 500 bits, the proposed method averagely takes about 15 minutes on Core 2 Quad (2.66Hz) for generating one.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama1349-6115442010High Accuracy Homography Computation without Iterations5059ENKenichiKanataniWe present highly accurate least-squares (LS) alternatives to the theoretically optimal maximum likelihood (ML) estimator for homographies between two images. Unlike ML, our estimators are non-iterative and yield solutions even in the presence of large noise. By rigorous error analysis, we derive a “hyperaccurate” estimator which is unbiased up to second order noise terms. Then, we introduce a computational simplification, which we call “Taubin approximation”, without incurring a loss in accuracy. We experimentally demonstrate that our estimators have accuracy surpassing the traditional LS estimator and comparable to the ML estimator.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama1349-6115442010Hyperaccurate Ellipse Fitting without Iterations4249ENKenichiKanataniThis paper presents a new method for fitting an ellipse to a point sequence extracted from images. It is widely known that the best fit is obtained by maximum likelihood. However, it requires iterations, which may not converge in the presence of large noise. Our approach is algebraic distance minimization; no iterations are required. Exploiting the fact that the solution depends on the way the scale is normalized, we analyze the accuracy to high order error terms with the scale normalization weight unspecified and determine it so that the bias is zero up to the second order. We demonstrate by experiments that our method is superior to the Taubin method, also algebraic
and known to be highly accurate.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama1349-6115442010Optimization without Search: Constraint Satisfaction by Orthogonal Projection with Applications to Multiview Triangulation3241ENKenichiKanataniWe present an alternative approach to what we call the “standard optimization”, which minimizes a cost function by searching a parameter space. Instead, the input is “orthogonally projected” in the joint input space onto the manifold defined by the “consistency constraint”, which demands that any minimal subset of observations produce the same result. This approach avoids many difficulties encountered in the standard optimization. As typical examples, we apply it to line
fitting and multiview triangulation. The latter produces a new algorithm far more efficient than existing methods. We also discuss optimality of our approach.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama1349-6115442010Improved Multistage Learning for Multibody Motion Segmentation2431ENKenichiKanataniWe present an improved version of the MSL method of Sugaya and Kanatani for multibody motion segmentation. We replace their initial segmentation based on heuristic clustering by an analytical computation based on GPCA, fitting two 2-D affine spaces in 3-D by the Taubin method. This initial segmentation alone can segment most of the motions in natural scenes fairly correctly, and the result is successively optimized by the EM algorithm in 3-D, 5-D, and 7-D. Using simulated and real videos, we demonstrate that our method outperforms the previous MSL and other existing methods. We also illustrate its mechanism by our visualization technique.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama1349-6115442010Unified Computation of Strict Maximum Likelihood for Geometric Fitting1323ENKenichiKanataniA new numerical scheme is presented for computing strict maximum likelihood (ML) of geometric
fitting problems having an implicit constraint. Our approach is orthogonal projection of observations
onto a parameterized surface defined by the constraint. Assuming a linearly separable nonlinear constraint, we show that a theoretically global solution can be obtained by iterative Sampson error minimization. Our approach is illustrated by ellipse fitting and fundamental matrix computation. Our method also encompasses optimal correction, computing, e.g., perpendiculars to an ellipse and triangulating stereo images. A detailed discussion is given to technical and practical issues about our approach.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama1349-6115442010Numerical Simulation of Acoustic Waves in a Two-Dimensional Phononic Crystal: Negative Refraction712ENKenjiTsurutaThe lens effect of acoustic waves in a two-dimensional (2D) phononic crystal is studied by numerical simulation based on the finite-difference time-domain (FDTD) method.
We calculate the phonon band structure of 2D phononic crystals, consisting of metal cylinders placed periodically in water. Lens effect is observed by the negative refraction of acoustic waves, which results in refocusing of the waves at the point outside the crystal. To increase the focal intensity, we introduce a 2D phononic crystal shield with a different composition of material, which returns the incident waves back to the lens via the perfect reflection. Also, the dependence on filling fraction of metal in the crystal is studied.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama1349-6115442010FDTD Analysis on Optical Connement Structure
with Electromagnetic Metamaterial16ENKenjiTsurutaIn this paper, we investigate a light-confinement phenomenon in the structure which has triangular latice composed of Double NeGative Metamaterial (DNGM). In
geometrical optics consideration, this structure is expected to confine lights completely by sequential refractions in the structure. We demonstrate it by using the two dimensional finite-difference time-domain simulations. We introduce Drude-Lorentz model for dielectric and magnetic dispersion of the material at optical frequencies. We analyze quantitatively the effects of energy loss in the DNGM on the light-confinement
efficiency.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00713321999A Study of Facility Layout Method in Recycling Plant using AGV111119ENYoshiomiMunesawaHirokazuOsakiOur country faces a serious problem of the environmental pollution by the production and the large quantity consumption of the industry product. The thoroughness of resources recycling has become necessary to solve these problems. As for the product design and the production control, how productivity should be improved has been discussed with extreme emphasis. But from now, as for the product design, both assemblability and disassemblability must be taken into consideration at the same time. And also in production management, it must be investigated how the products can be recycled in the low cost. Therfore, the facility layout method with two phases in recycling plant, which is composed of both the procedure for the layout of facility group and the procedure for the layout of intermal facility group by the optimal solution method and the suboptimal solution method by neural network is proposed in this paper.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00713321999An Analytical Method of Human Motion by Image Processing105110ENHirokazuOsakiThis paper deals with analytical method of human motion by image processing to make a model of the scooping process, Firstly, the scooping tool is the spoon, and while the scooping process is performing, the movement of the mouth center position and the spoon top position are measured by two cameras. As the amount of substance is over the uppermost area of the cup, the spoon is stuck obliquely into substance. Then the spoon is rotated and lifted up to the mouth. Secondly, we recognize the mouth center from the characteristic of the face image data and calculate the spoon top position to extract two points on the spoon handle from the time series images by two cameras. Finally, we describe the method of recognizing the coordinate of the mouth center and estimating the coordinate of the spoon top to analyse the scooping process.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00713321999Intelligent Monitoring System Using Multiviewpoints for Teleperation9196ENYoshiomiMunesawaHirokazuOsakiYasuhiroKajiharaIn this paper, we propose the method to determine the position of the 2 cameras for the multiviewpoints as the robot is the work place. The optical axit's direction of the 1st camera is determined in the base ot work contents in teleoperation. The multiviewpoints system uses the 2 camera units that aren't installed side by side, so that the direction of the 2nd camera is decided in the base of the angle between the optical axes' direction of 2 cameras. Next, the distance from the camera to the work place is determined according to the distance resolution of image on the monitor, and the camera type of which the point-blank range is not this distance is selected. And the efficacy ot this system is examined with an experiment.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00713321999A Method of Shape Recognition Using CAD Data and Vertex-Dictionary8589ENMitsuruYamadaHirokazuOsakiWe reason the circumstances around the three-dimensional vertex from the information about the intersection point in the two-dimensional image data inputted from a camera on the premise that we use this method as the eye ot the robot. In this method, we use the Vertex-Dictionary. We make the Vertex-Dictionary by calculation from CAD data of object figure (these data are already known) and the position data of the point of view. This dictionary includes the data of position and relations of connect surface etc. about a vertex. We get the data of three-dimensional vertex by comparison the data of two-dimensional intersection point in image data and Vertex-Dictionary. And we get the three-dimensional object by reasoning about the information of circumstances of all vertexes. Then we can recognize the three-dimensional object from image data. In this report, we explain the process to calculate the Vertex-Dictionary and some examples about this method.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00713321999Apatite Formation on Electrochemically Treated Titanium7984ENAkiyoshiOsakaSatoshiHayakawaKanjiTsuruA titanium oxide gel was electrochemically prepared on Ti with a cell consisting of Ti as the working electrode, Pt as the counter one, AgCl as the reference one, and an aqueous solution of 0.1 mol/L Ca(NO(3))(2) as the electrolyte solution. The Ti electrode was kept at 9.5V for 1 hr for oxidation and subsequently kept at-3.0V for 10 min (Ca9.5-3.0):calcium ions were expected to be adsorbed at the latter treatment. Other Ti specimen was kept at -3.0V for 10 min (Ca-3.0). Both specimens were found so bioactive as to deposit apatite in 12 hr (Ca9.5-3.0) and in 1 day (Ca-3.0) when soaked in a simulated body fluid (Kokubo solution). Calcium carbonate detected on the surface of Ca9.5-3.0 caused no harmful effects on spontaneous deposition of apatite in the fluid.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00713321999O(N) Tight-Binding Algorithm for Large-Scale Molecular Dynamics Simulations7177ENKenjiTsurutaHirooTotsujiChiekoTotsujiA parallel tight-binding molecular dynamics with an order-N [O(N))] algorithm is implemented to perform large-scale simulation of nanostructured materials. The algorithm is based on the Fermi-operator expansion of an electronic energy and force, and we present its basic formalisms. Accuracy necessary for molecular-dynamics simulations can be obtained by a proper truncation in the expansion. Parallel efficiency on a parallel PC cluster shows nearly ideal scaling behavior with respect to the number of processors. Applicability of the method to a silicon-carbide system is examined.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00713321999Multicomponent Plasmas in Penning-Malmberg Traps6169ENHirooTotsujiKenjiTsurutaChiekoTotsujiThe behavior of multicomponent plasmas in the Penning-Malmberg traps is discussed with the parameters corresponding to experiments with antiprotons and cryogenic electrons. The relaxation times for the energy transfer antiprotons to electrons and between parallel and perpendicular components of electrons are estimated. It is shown that, depending on the values of parameters, both the former and the latter can be the bottleneck in the cooling process.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00713321999Density Functional Molecular Dynamics of Hydrogen Plasma5159ENHirooTotsujiKenjiTsurutaChiekoTotsujiDensity functional molecular dynamics method is applied to hydrogen plasma in the domain of liquid metallic hydrogen. Tentative results for the proton-proton pair distribution function and the electron-proton pair distribution function are obtained. It is shown that with the increase of the parameter γ(s), we have increasingly strong screening of proton charge by electrons and the decrease of electron density in the domain between protons.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00713321999Measurement System of Biomechanical Properties for Portable Use4550ENHisaoOkaIt is difficult to evaluate a biomechanical properties quantitatively. The authors developed the measurement system of biomechanical properties formerly but it is on a large scale because of the use of personal computer. In this study, the portable measurement system of biomechanical impedance/mobility is developed. To establish a rapid measurement, a random vibration is adopted in input signal. The system consists of the measuring probe, amplifier, and a note-typed personal computer. The measurement probe is developed newly, and has an overall length of 9 ㎝ (without a handle) and a total weight of about 500 g. The measurement program is also developed and is available to any computer which is worked under MS DOS compatible in Windows 95/98 operating system. The biomechanical spectra of thigh, temple and forehead are obtained and they show three typical spectrum patterns.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00713321999Acousticmyogram Measured with Electrosimulation During Muscle Fatigue3944ENHisaoOkaThe acousicmyogram (AMG) is a mechanical phenomenon recorded at the surface of an active muscle. It is used to monitor force production, fatigue, and contractile properties of muscle. In this study, the new electrode with accelerometer for electrostimulation and acoustic detection. It consists of Ag-AgCl active electrode and solid-gel annular groud, and a very light piezoresistive accelerometer. The recorded AMG waveform depends on the pulse amplitude and duration of stimulation current and its lag from the electroatimulation is about 7 ms. The strengh-duration (S-D) curve (the threshold current for stimulation vs. pulse duration) describes the excitability of muscle. The left forearm is electrostimulated by using the same electrode and the muscle vibration (AMG) is recorded with accelerometer. During the muscle fatigue, the S-D curve changes and the current threshold increases under the same pulse duration. The rheobase of S-D curve increases gradually but the chronaxie hardly changes during muscle fatigue.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00713321999A Numerical Study on the Performance of an Open-type Flat-plate Solar Collector2537ENHideoInabaAkihikoHoribeA set mathematical models was developed for predicting the performance of an open-type flat-plate solar collector, and solved numerically through an implicit difference method. The effects of various parameters on the absorption of solar energy for the collector were investigated. The results showed that the solar energy absorptance of the open-type flat-plate collector was relatively high especially for the region where the weather was humid and hot, and there were an optimum length and an optimum tilt angle for the absorbing plate on which the collector could obtain the highest solar energy absorptance. It was found that the latent heat flux of water evaporation could be 5 to 15 times larger than the sensible heat flux. The effects of the magnitude of the solar incident flux, the atmospheric humidity, the atmospheric temperature, the absorbing plate tilt angle, and water film thickness on the temperature rising of the water film were clarified in numerical quantities. The increase of the solar incident flux, the atmospheric humidity or the atmospheric temperature also resulted in a rise in the energy absorptance of the collector.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00713321999Small Type Hydrocyclone with a Perforated Inner Cylinder1924ENKyojiYamamotoA new type of hydrocyclone with a perforated inner cylinder is tested experimentally to study its performance for liquid-solid separation. The size of the cyclone is small so that it may be effective for small particle separation. Two types of the inner cylinder were made : the one has 39.5% void fraction of the perforated surface and the other has 73.5% . The mean particle diameter is 4.5 μ m. It is found that the pressure loss of the cyclone with the inner cylinder is reduced by about 25% compared with that of the ordinary type. The new type cyclone has better separation efficiency.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00713321999Rarefied Gas Flow Over a Solid Surface with Adsorbates917ENKyojiYamamotoThe molecular dynamics study is applied for interaction of the gas molecule with the solid wall to analyse the flow of a rarefied gas between two wall. The wall consisting of Pt molecules is considered to be in a state of physical adsorbates. Two problems are considered : one is the flow problem and the other is the temperature problem. It is found that the tangential momentum accommodation coefficient is about 0.8 when the relative speed ratio of the two walls is unity, while it decreases with increasing Knudsen number when the relative wall speed ratio is 5.0. It shown that the temperature accommodation coefficient is about 0.85 at 300K wall, 0.75 at 450K wall, and 0.69 at 600K wall.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00713321999Simulation of Deformation of Ni Twinned Nanocrystal Model by Molecular Dynamics18ENYasuhiroOmuraMoritakaHidaAkiraSakakibaraYoshitoTakemotoMolecular dynamics simulation of nickel crystal under uniaxial tensile and compressive deformation was performed for single nenocrystal model and twinned nanocrystal model composed of 1550 atoms using EAM (embedded atom method) potential with the object of investigating deformation induced phase tranformation (especially twin deformation). In the case of single nanocrystal model, the evolution and development of twin deformation, (111)[11(2)], is observed under compressive loading in [001] direction, whereas either slip or twin deformation is not recognized under tensile loading. In the case of twinned nanocrystal model, twin, (111)[11(2)], decreases and disappears under tensile loading, and develops under compressive loading, It is suggested from the difference of results between single nanocrystal model and twinned nanocrystal model that it is easy for twin to induce local deformation.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-0071321-21998Numerical Analysis of a Model for Isolated Hydrogen Bond4354ENChiekoTotsujiLarge isotope effects have been observed in various kinds of hydrogen bonded ferro / antiferroelectrics. In clariflying their origin, themodynamic properties of the hydrogen bond are of essential importance. Two numerical methods are applied to analyze the model for isolated hydrogen bond at finite temperatures and the results of excited energy levels of proton or deuteron are examined. It is found that the second excited state is not far enough from the first excited state to be neglected discussing themodynamic properties of hydrogen especially in their ordered states.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-0071321-21998Structure of Yukawa (Dusty Plasma) Mixtures2341ENHirooTotsujiTokunariKishimotoChiekoTotsujiParameters characterizing the structure ot confined Yukawa system are estimated for 'dusty plasmas', clouds of charged macroscopic particles formed near the boundary between plasma and the sheath and leviated by negatively biased electrode. When we have dust particles with different ratios of charge to mass, they form a two-dimensional Yukawa mixture or separate two-dimensional one-companent Yukawa systems, depending on the charge density in the sheath and number density of dust particles. In order to provide a basis for numerical simulations on Yukawa mixtures including Coulombic case, we summarize mathematical expressions necessary for molecular dynamics.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-0071321-21998Internal Structure and Viscoelasticity Estimation by a Mechanical Impedance - In case of a vibrating disk -1522ENMasahiroMoriHisaoOkaIn a stiffness estimation of living body, an internal structure under the skin influences the measured results. Because a different stiffness of body caused by bones and muscles is obtained. In this paper, by using a measurement system of mechanical impedance, the relations between a viscoelasticity and a distance from the surface of silicone-gel model is calculated. This relation is applied to silicone-gel tumor model and a shape and a viscoelasticity of semi-sphere silicone-gel tumous are estimated. The obtained results are expressed as a reconstructed 3-D image of shape / viscoelasticity. The revised curve-fitting of mechanical impedance and the cancellation of peripheral vibration influence are proposed in order to increase an estimation acccuracy.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-0071321-21998Comparative Considerations of Eliminating Method for Power Line Interference in Electrocardiography714ENYoshitakeYamamotoThis paper describes a new measurment method and principle of power line interference elimination in ECG signal using inverse loop and AC power line configuration (APC). First, we considered that magnetic induction effect not only depend on a conductive loop area that formed by shielded wires that connect the object and amplifier but also effect of body area effective must be considered. It is simple and useful because interference can be eliminated to very small value show that the condition and it can be applied in a real ECG signal recording. Second, results show that the contribution of displacement currents into the object especially APC in vertical configuration is smaller than it in other one. Because this method is so easy that it is convenient to be used to understand some aspects of power line interference elimination phenomenon. Hence we expect that this method can be used as one of improvement method in measurement system of ECG signal recording.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-0071321-21998Study on Electrical Discharge Machining Characteristics of Coated Electrodes16ENChangningGuoYoshiyukiUnoAkiraOkadaTakashiTakagiLow electrode wear EDM is attained by the adhesion of heat resolved carbon made from kerosine type machining fluid to the electrode end surface. This phenomenon, however, occurs only under long pulse duration. Therefore, the low electrode wear EDM under finishing condition is impossible so far. In the previous paper, the authors developed a turbostratic carbon electrode whose structure is very similar to the heat resolved carbon generated in EDM process and made it clear that the low electrode wear EDM was possible by using the electrode even under finishing condition. In this study, a carbon coated electrode and a SiC coated one which can be made rapidly at low cost were developed and their EDM characteristics were investigated. Experimental analysis pointed it out that both electrodes were effective in reducing electrode wear under finishing condition.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00713111996Synthesis and Characterization of Poly[(benzo[1,2-d:5,4-d']bisthiazole-2,6-diyl)-1,4-phenylene]1117ENTetsuyaUchidaKaoruShimamuraPoly[(benzo[1,2-d:5,4-d']bissthiazole-2,6-diyl)-1,4-phenylene](cis-PBZT)with a relatively high molecular weight was prepared by a new synthesis route. Properties of the synthesized polymer, such as thermostability, liquid crystallinity etc. were investigated and compared with those of trans-PBZT. cis-PBZT was crystallized from dilute solution and the electron microscopy showed that the precipitate was a rod-like crystal similar to that of trans form. In spite of rigid nature of the back bone, cis-PBZT showed poor crystallinity.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00713111996Solution-Grown Crystals of Poly(p-phenylene benzobisthiazole)510ENKaoruShimamuraTetsuyaUchidaRigid polymer poly(p-phenylene benzobisthiazole) was crystallized from dilute solution. Electron microscopy showed that upon quenching, flat fibrils with several nm thick were produced. Subsequent heat treatment in solvent changed the fibril into "shish-kebab". On the other hand, by isothermal crystallization, an aggregate of parallel rod-like crystals was obtained. The molecular chains were accommodated normal to the rod. Based on the observation of crystal morphology, the isothermal crystallization mechanism was proposed. Because of regidity of polymer chains and wide distribution of the molecular length, the chain ends were inevitably included within the crystals resulting in crystal defects such as axial shift, lattice curvature and edge dislocation which were directly observed by lattice imaging.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00713111996Precipitation Hardening and Effect of Surface Layer on the Fatigue Strength of an Al-1.2mass% Si Alloy13ENAkiraSakakibaraKeiyuNakagawaNorioHosokawaTerutoKanadaniDependence of precipitation hardening on the distance from specimen surface and effect of the surface layer on the fatigue strength of an Al-1.2mass% Si alloy were studied by microhardness test, transmission electron microscopy and repeated tension fatigue test. Rate of age-hardening was slower in the vicinity of surface than in the interior of the specimen aged at 423K after quenching from 853K. The result of the electron microscopy was that the size ot Si precipitates formed in the vicinity of surface was smaller than in the interior of specimen aged for 6ks at 423K. This difference was considered to be caused by the effect of the surface as vacancy sinks which slowed down the growh of Si precipitates in the vicinity of the specimen surface. A specimen surface layer whose hardness was different from that of the specimen interior was formed at the vicinity of the surface when the specimen was aged at relatively low temperature such as 423K. The fatigue strength in repeated tensile test ot the specimen did not depend on whether the specimen surface layer was present or not.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00713311998Facility Layout Linked with Scheduling Problem by Genetic Algorithm and Tabu Search5964ENHirokazuOsakiIn this paper, we propose a method to solve simultaneously facility layout problem and scheduling problem. About a initial random layout planning, the production scheduling and the transportation scheduling of AGV are obtained by using priority rules. From the obtained transportation scheduling, the critical transportation and the closeness rating are obtained. Facility layout is renewed by the combined procedure of genetic algorithm and tabu search in order to reduce the material handling cost. By using this renewed facility layout, the production scheduling and the transportation scheduling of AGV are also revised until no further improvement is possible.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00713311998A Method for Designing an Automatic Monitoring System for Unmanned Rooms5357ENHirokazuOsakiYasuhiroKajiharaYosiomiMunesawaA method for designing a monitoring system with multiple cameras is proposed in order to supervise and recognize the progress of wide work area. First, a wide view camera is deveeloped by combining several usual cameras so that its visual angle could cover more than π/2. Secondly, A method for determining the number and location points of cameras is proposed by considering the shape of monitored area and the installation cost of cameras. The monitored area is divided into three kinds of basic shape (rectangular form, L form and convex form). For every basic shape area, the camera is located at the vertex pasition, so that the whole area can be monitored by the camera.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00713311998The Recognition Methods Combined Image Processing With 2D or 3D CAD Information (CAD/IP)4752ENMitsuruJindaiHirokazuOsakiYasuhiroKajiharaYosiomiMunesawaIn this paper, we propose the recognition methods by image processing using 2D or 3D CAD. In the case of 2D CAD, an object is recognized by comparing five characters calculated from the center of gravity and contour. In the case of 3D CAD, there are two recognition methods. Firstly 3D CAD figure is transformed into 2D CAD figures. And an object is recognized by comparing 2D CAD figures with inputted images. Secondly the three dimensional coordinates of vertexes on an object are calculated from the images taken from some cameras and compared 3D coordinates with those of 3D CAD figures and recognized the sort of an object.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00713311998Recognition Index of Part and Unit by Discrimination Characteristics3945ENYoshiomiMunesawaHirokazuOsakiYasuhiroKajiharaIn this paper, we propose a recognition index to evaluate the complexity of discrimination among parts and units. The parts and units are classified into some groups (the number of groups is shown as n) by one characteristic, such as color, shape, size and so on. The recognition index of each is denoted as log(2) (n+1) by the information quantity formula. The recognition diagram shows the classfication of parts and units into only one part and unit by the structure of a characteristic. Further we propose the line balancing method for assembly line based on the working time and recognition index.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00713311998A Study on Robot System to Hand Surgical Intrument to a Surgeon in a Surgery (1st Report, Development of Surgical Instrument Recognition System)3137ENHirokazuOsakiYasuhiroKajiharaYoshiomiMunesawaShujiSekiThe nurse supporting robot system to prepare and hand surgical instruments to a surgeon is proposed to reduce work of nurse in a surgical operation. In this paper, the surgical instrument recognition system (SIRS) is developed to hand the surgical instruments to a surgeon by the robot. The characteristics ot the instruments are area of the instruments, ratio of minimum center-contour distance to maximum one and its outline contour, are recognized by using the image processing. Kinds of the instruments are distinguished by these characteristics.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00713311998Measurement of saturated solubilities and diffusion coefficients of pure gases to mineral oil1930ENSeiichiWashioSatoshiTakahashiChikashiImotoAtsumasaYoshidaThe present paper deals with measurements of the diffusion coefficients as well as the saturated solubilities of single component gases such as N(2), O(2) and CO(2) to a mineral oil. The method to determine the diffusivity is based upon measuring the pressure changes caused by the one-dimensional diffusion between the gas and the oil enclosed in an airtight container. For N(2) and O(2) the profiles of the measured pressure changes agree well with those predicted by diffusion theory, whereas that is not the case with CO(2). Although the reason why CO(2) does not seem to obey diffusion theory has yet to be studied, it may suggest the possibility that the diffusion coefficient varies with the pressure, considering that the range of pressure change in the diffusivity measurement was much obtained by this method fell within ±30% around the average. Moreover the solubility measurements have made clear that Henry's law holds true between the three pure gases and the oils tested, and that O(2) and CO(2) dissolve into the oil approximately two and ten times more, respectively, than N(2).No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00713311998Rigid-Plastic Deformation of Inhomogeneous Material with Elliptic Inclusions Sliding along Boundary517ENTakejiAbeThe influence of the slip between the inclusion and the matrix during the plastic deformation of inhomogeneous material with elliptic inclusions is investigated. The material is assumed to be rigid-plastic. The boundary slip region is modeled by assuming lower yield stress for the thin boundary region than those of the inclusion and the matrix. The rigid-plastic finite element method is used for the numerical calculation under the plane strain condition. The effects of the aspect ratio of the inclusion, the yield stress of the boundary region, and the volume fraction of the inclusion on the deformation mode are studied. The patterns of the strain concentration and the averaged flow stress of the inhomogeneous material are also discussed. The results may be helpful for understanding creep or superplastic deformation of metals with inclusions.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00713311998Effect of Solute Clusters on Low Temperature Aging in Dilute Al-Ag Alloys14ENAkiraSakakibaraTerutoKanadaniAging of diolute Al-Ag alloys after quenching from low temperatures were studied mainly by electrical resistometry. Maximum resistivity observed in the aging curve of specimens quenched from high temeperature disappeared when the quenching temperature was lowered to 473 or 453K. When the quenching temperature was lowered further to 423K or lower, however, maximum resistivity reappeared. At the temperature lower than or equal to 423K but higher than the GP zone solvus, the alloys were not homogeneous but had clusters of solute atoms or fluctuation of solute concentration. Inhomogeneous distribution of solute atoms may affect the aging behavior after quenching from that temperature.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00713121997Price Determination Method Based on Price Elasticity6772ENHirokazuOsakiYasuhiroKajiharaIn this paper, we propose the price determination method using the parameter of the price elasticity that shows the relation between price and demand. Firstly, the state of the price elasticity is examined under the condition that the relation between price and demand are assumed by the inverse proportional function, the linear function and the quadratic function. Secondly, the profit is estimated for each product by break even point analysis. And the price is determined under the condition that the relation between the demand and price is shown by one of three demand-pridce functions above mentioned.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00713121997A Method of Shape Recognition Using Geometry Information6165ENHirokazuOsakiAt present, the two dimensional CAD systems which are used to make drawings go around widely. But in order to use design data at the lower stream of production process, the replacement from the two dimensional CAD systems to the three dimensional CAD systems have started. Accordingly it is dimensional drawings for the three dimensional shapes. And it is also necessary to store them in the three dimensional CAD systems. And in the studying of the machine vision which is often used as "Eyes of robot" , it is being studied the method to recognize the three dimensional objects from the two dimensional image. This is the problem about data exchange, too. Therefore in this report, we propose the method to exchange the plural two dimensional elements of figure from image relations between elements were found from reference of the element coordinates. Next, the three dimensional shapes were reasoned from reference of the knowledge (for corner, etc) prepared beforehand. Then that data were exchanged to the three dimensional CAD data. We report one example about this method.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00713121997Plant Layout Method Considering Material Handling Cost and Maintainability5360ENHirokazuOsakiThis paper presents a method using simulated annealing(SA) and genetic algorithm(GA) to solve the plant layout problem in which the layout is evaluated by material handling cost and maintainability. In the former study about facility layout problem, it was either the minimization of the objeective function consisting of transport cost or the maximization of the objective function consisting of closeness rating. In this paper, both transport cost and maintainability were included in the objective function to be minimized. The plant layout problem, this paper proposes the heuristic procedures to obtain a suboptimal layout solution by combining SA with GA. From the simulation by computer, it concluded that the method which SA is combined with GA is more efficient than the method which utilizes SA and GA independently.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00713121997Bioactive Calcium Borosilicate Glasses for Enameling Titanium4551ENAkiyoshiOsakaSatoshiHayakawaChikaraOhtsukiThe thermal expansion coefficient of some bioactive glasses in the system CaO-SiO(2)-B(2)O(3) were adjusted to be similar to that of titanium by controlling the composition. A glass of composition 45CaO･30SiO(2)･25B(2)O(3) was selected among those as the enameling glass. A slurry was prepared by mixing the glass powder and ethanal to be developed on titanium and heated at 740℃ for 30 min. Thus treated specimen was soaked in a simulated body fluid (Kokubo solutiion). FT-IR reflection and thin film X-ray diffraction analyses indicated apatite formation on the glass coating layer within 12 h of soaking in the fluid. Thus titanium could be provided with bioactivity due to the enameling.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00713121997Bioactivity of Nb(V) and Ta(V)-Doped Calcium Silicate Glasses3944ENSatoshiHayakawaChikaraOhtsukiAkiyoshiOsakaNb(2)O(5)-and Ta(2)O(5)-doped calcium si1icate glasses were soaked for various periods in a simulated body fluid(Kokubo solution) up to 30 days. Apatite formation ability of the surface of these glasses were investigated with thin-film X-ray diffraction and FT-IR reflection spectroscopy. The effects of these additive oxides on the bioactivity of CaO･SiO(2) based glass were discussed. A small amount of Nb(2)O(5) and Ta(2)O(5) suppressed the rate of silica hydrogel layer formation and the apatite formation on the surface of the glasses. The rate of the apatite nucleation on the surface of Nb(2)O(5)-doped calcium silicate glass was slower than that on the surface of Ta(2)O(5)-doped calcium silicate glass. It was concluded that the decrease in the apatite forming ability of calcium silicate glasses by these additive oxides is attributed to the suppression of formation of silica hydrogel layer which plays an important role in apatite nucleation.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00713121997Estimation of Loosening of Knee Joint Prosthesis2937ENHisaoOkaMasakazuOhshimaKnee replacement arthroplasty is indicated for the patient with advanced knee pain, knee deformation, and knee functional disorder. The aim of this study was to estimate loosening after a knee replacement arthroplasty. Loosening is measured by a frequency response function, and mobility by random vibration. The modal parameters for the knee joint are obtained by applying a modal analysis to the frequency response function. The values decrease as the knee joint prosthesis loosened. These parameters serve as an index for the condition between a thighbone and the prosthesis. The various indexes will greatly clarify the stage of advance in the loosening of knee-joint prostheses.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00713121997Estimation of Internal Viscoelasticity by Mechanical Impedance2127ENHisaoOkaTakahikoNakamuraIn evaluating the stiffness of skin surface, internal structures such as bone and muscle often affect the measurements. In the present paper, acoustic random vibration is used to estimated the viscoelasticity of a silicone-gel model. This viscoelasticity, which includes two different stiffness strata, is first estimated using a mechanical impedance spectrum, which describes the relation between the depth and viscoelasticity of internal objects. This method is applied to the depth of a silicone-gel tumor model measured by ultrasound imaging and the viscoelasticity of internal gel can be accurately estimated.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00713121997Internal Structure and Phase Transformation of Ti-V Alloy Fine Particles1120ENYoshitoTakemotoMoritakaHidaFine particles of Ti-V alloy were prepared by means of arc method and were investigated on internal structure and phase transformation using HR-TEM and EDS. Martensite phase was observed in a particle containing comparatively low concentration of V, and ω phase was also found to exist in a nearly 15% V particle. The structure of the ω phase in the fine particle is remarkably expanded in comparison with the bulk sample, and the ω phase is unstable, so that it has disappeared in a few seconds during TEM observation.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00713121997Microstructure of Oxide Layers Formed on Magnesium Surface at Elevated Temperature110ENYoshitoTakemotoMoritakaHidaThe microstructure of oxidizing magnesium at elevated temperatures has been studied using HR-TEM, SEM and EDS. Two kinds of thin magnesium specimen for TEM observation were prepared. One was oxidized after preparing TEM foil of magnesium, the other was prepared from an oxidized bulk magnesium for observing the cross-section of oxide/Mg interfacial region. In the former, several oxides(MgO) morphologies were observed depending on the temperature and time of the oxidization. The growth of needle-like oxides formed at 573K and mottled oxides formed at 773K were recognized as a remarkable phenomenon belonging to the local oxidization. These oxides were composed of poly-crystal. The thin uniform oxidization layer was also observed in all conditions. In the cross-sectional observation, the local oxide layer, nearly 300nm in thickness, on the matrix(Mg) were observed. The thin uniform oxidized layer of bulk samples was identified as a kind of modified layer (~40nm in thickness) in which the formation of HR-TEM lattice fringes were prevented by the strain due to the slight oxidization.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00712911994Study on Water Quality of Surface Runoff and Groundwater Runoff on the Basis of Separation by a Numerical Filter2334ENOsamiKawaraIn this study we investigated the water quality of surface runoff and groundwater runoff from the basins of the Yodo River and the Asahi River based on that separated by a numerical filter. The water quality of the surface runoff is greatly different from the groundwater runoff. The tendency of concentration change in accordance with river discharges is different from each other. The water qtiality of groundwater runoff changes with river discharges clockwise in many cases. The differences of COD and SS originating from those of population and industrial activities in each basin are found in the lower SS concentrations of the surface runoff and the COD cencentrations of the groundwater runoff. The nutrients and chlorine ion were investigated, too.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00712911994Scribing of Ceramie Circuit Board with Q-Switched Nd：YAG Laser16ENYoshiyukiUnoShin-ichiroKubotaSeiichiYokomizoKojiroOgataNobuhikoTadaScribing of copper coated alumina ceramic board with Q-switched YAG laser used for the maskless direct patterning of circuit board is experimentally investigated, which leads to efficient production of trial circuit board. Better dividing of alumina circuit board 655μm in thickness can be attained by the scribing of about 100μm depth. Higher repetition frequency of laser irradiation leads to smaller notch angle and lower breaking load.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama1349-6115432009Cost Evaluation of The Improvement of Twisted Ate Pairing That Uses Integer Variable X of Small Hamming Weight113116ENYumiSakemihidehiroKatoYasuyukiNogamiYoshikawaMorikawaBarreto–Naehrig (BN) curve has been introduced as an efficient pairing-friendly elliptic curve over prime field F(p) whose embedding degree is 12. The characteristic and Frobenius trace are given as polynomials of integer variable X. The authors proposed an improvement of Miller's algorithm of twisted Ate pairing with BN curve by applying X of small hamming weight in ITC–CSCC2008; however, its cost evaluation has not been explicitly shown. This paper shows the detail of the cost evaluation.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama1349-6115432009Extension Field for Xate Pairing with Freeman Curve108112ENKentaNekadoHidehiroKatoYasuyukiNogamiYoshitakaMorikawaRecently, pairing-based cryptographies such as ID-based cryptography and group signature have been studied. For fast pairing calculation, not only pairing algorithms but also arithmetic operations in extension field must be efficiently carried out. The authors show efficient arithmetic operations of extension field for Xate pairing especially with Freeman curve.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama1349-6115432009A High-Speed Square Root Algorithm for Extension fields -Especially for Fast Extension Fields-99107ENHidehiroKatoYasuyukiNogamiYoshitakaMorikawaA square root (SQRT) algorithm in extension field F(p(m))(m = r(0)r(1)･･･r(n−1)･2(d), r(i) : odd prime, d : positive integer) is proposed in this paper. First, a conventional SQRT algorithm, the Tonelli-Shanks algorithm, is modified to compute the inverse SQRT in F(p(2d)), where most of the computations are performed in the corresponding subfields F(p(2i)) for 0 ≤ i ≤ d-1. Then the Frobenius mappings with addition chain are adopted for the proposed SQRT algorithm, in which a lot of computations in a given extension field F(p(m)) are also reduced to those in a proper subfield by the norm computations. Those reductions of the field degree increase efficiency in the SQRT implementation. The Tonelli-Shanks algorithm and the proposed algorithm in F(p(6)) and F(p(10)) were implemented on a Core2 (2.66 GHz) using the C++ programming language. The computer simulations showed that, on average, the proposed algorithm accelerated the SQRT computation by 6 times in F(p(6)), and by 10 times in F(p(10)), compared to the Tonelli-Shanks algorithm.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama1349-6115432009Predictor Order and Error Distribution of MMAE Predictors for Lossless Image Coding9398ENHirokazuUenoYoshitakaMorikawaThis paper investigates the relation between error distribution and predictive order of minimum mean abusolute error predictors (MMAE predictors) designed for lossless coding of grayscale images. Design of MMAE predictors reduces to the linear programming problem. Let k be the number of coefficients in a predictor (predictor order), we imagine that predictor order k may have a distribution shaping effect. Main purpose of this paper is to ensure that k has such an effect.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama1349-6115432009Human Support Agent for Design and Diagnosis using Classifier System7592ENKeitaOheMasamiKonishiJunImaiAs is well known, an advanced knowledge and know-how are needed in the design and the diagnosis work. Further, human experts can cope with the recent trend of customers
needs. Therefore, the design and the diagnosis work have been privately performed in the past, and its information cannot be shared. In addition, the number of experts is decreasing. It is a very important problem to maintain and to extend experts technologies having been built up. For the purpose, methods and systems for technical inheritance of the advanced techniques of the skilled engineers are needed to train the unskilled operators and also can assist skilled operators. In this research, attention is focused on the design of analog filter circuit. To attain the target, the circuit structural classifier system to support design work is developed. Furthermore, simulation technology for hot strip rolling mills based on distributed agents is presented aimed to develop tools for the diagnosis of hot strip rolling mills operation.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama1349-6115432009Human Interface Technology for Operation Support of LargeSized Crane6174ENMaoKawamuraMasamiKonishiKatukiYamagataKoichiShimomuraIn this research, a Human Interface system is designed intended to mobile crane. The intervention of human is unavoidable to attain the high performance of electro mechanical system. As is known, crane operation is complicated. Recently, the decrease of expert person induced crane accident. So in near future, it is required a partial automation of crane operation and human support technology. We are aiming at the development of the operation support system for a crane. In this research, development of the hydro mechanical models representing both of static and dynamics movements are made. Further, actual experimental data of operating mobile crane, which are electrical signal data and three-dimension (3D) position of moving load is measured. The actual operating data are compared with the model and it is found that the developed electromechanical model can explain the behaviors of actual data.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama1349-6115432009Surface Defect Inspection of a Cutting Tool by Image Processing with Neural Networks5560ENShinichiroInoueMasamiKonishiJunImaiIn this research, an image processing method and a system for inspection support of a rod figured cutting tool are developed. As is well known, the visual inspection of a cutting tool by image processing is not easy, because cutting blade have a helical blade structure. To cope with the problem, an experimental facility with rotation and longitudinal tool shift functions to enable acquisition of blade surface pictures along a cutting rod is developed. The type of the defect treated in this paper is the spot of coating on blade surface. To judge the quality of the processed image of blade surface, neural network with autonomous learning is used. The processed image of cutting tool is divided into 64 × 64 blocks used for the
input to the neural networks. Before input, each block data is preprocessed applying a edge detection filter and a transformation by the discrete fourier transform (DFT). Using these technologies, the experimental inspection system is built and tested to check the capabilities of the inspection algorithms. The diagnostic performance of the surface defect of a cutting tool was confirmed. There remained a problem to mis judge the normal tools as the defect.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama1349-6115432009Position Control of 2-Link SCARA Robot by using InternalModel Control4954ENShinyaAkamatsuMasamiKonishiJunImaiIn this paper, the controlled target is the SCARA robot with two links, and the object is fine control of the arm head position of the robot. To attain the object, Internal Model Control (IMC) is introduced. A nonlinear equations are for robot dynamics formulated by solving Lagrange equation, and is linearized to design control system by IMC. The controller of IMC is designed or synthesisted as the inverse system of the linearized model, and IMC filter model is selected. Also, reference filter is introduced to make the improvement of performance. The result of control performance by IMC is compared with that of PID numerically, accuracy and incoherency are confirmed.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama1349-6115432009Positioning Control of One Link Arm with ParametricUncertainty using Quantitative Feedback Theory3948ENTakayukiKuwashimaJunImaiMasamiKonishiThis paper presents method of the controller design for one link arm with parametric uncertainty. Recently, many manufacturing robots are operated in manufacturing facilities, with the aim of labor and cost saving or improvement of the productivity. Such robots need to have positioning performance of high precision. In condition that there is an uncertainty in plant dynamics, desired control performance may not be attained because the
controller is designed according to the mathematical model of a plant. So it is important that the designed control system have a robust control performance. In this paper, the robust controller is designed using Quantitative Feedback Theory (QFT) for one link arm with parametric uncertainty. Simulation experiments are run for control system designed by using QFT and conventional method. The results are compared with each other and it is found that the control system designed by QFT shows a robust performance and can suppress the unevenness of output against parametric uncertainty.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama1349-6115432009Tracking Control of Combination Vehicles with PreviewFeedforward Compensation3238ENShujiMabuchiMasamiKonishiJunImaiA tractor-trailer vehicle in the factory might move on the route determined beforehand. However, automation of a tractor-trailer vehicle is difficult so that it is necessary to consider the nonlinearity of a vehicle and a trailer. In this research, the effective tracking control
method of a tractor-trailer vehicle is proposed. The control method using time-state control form for a preview control is presented, and be applied a tractor-trailer vehicle with nonholonomic characteristics. Results of numerical experiments are presented to check effectiveness
of the proposed control method.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama1349-6115432009Experimental Conditions for Observation of Thermodynamic
Instability and Critical Point of Fine Particle (Dusty) Plasmas2731ENHirooTotsujiWhen the Coulomb coupling between fine particles becomes sufficiently strong in fine particle plasmas, the isothermal compressibility of the whole system diverges and we have a phase separation and an associated critical point. Experimental conditions of fine particle plasmas, densities and temperatures of components and the fine particle size, are obtained corresponding to characteristic parameters around the critical point and the dependency on ion species and other factors is discussed.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama1349-6115432009Information Transfer and Entanglement Creation by Spin Chains: Effects of Noise and Asymmetry2226ENHirooTotsujiChiekoTotsujiKenjiTsurutaFor the transfer of quantum information and the creation of entangled states, the application of tuned spin chains, systems of spins with the nearest-neighbor coupling tuned so as to give high efficiency, has been proposed and some examples of high performance have been given by several authors. In this article, the effect of deviations from tuned values and the effect of resultant asymmetry are investigated through numerical simulations and theoretical analyses. It is shown that there exists a system where the transfer efficiency is comparable with exactly tuned ones and, at the same time, robust to noises in the coupling constants. It is also shown that the effect of asymmetry on the efficiency of entanglement creation is of the second order when the asymmetry is small.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama1349-6115432009FDTD Simulations of Acoustic Waves in Two-Dimensional
Phononic Crystals using Parallel Computer1621ENKenjiTsurutaChiekoTotsujiHirooTotsujiThe finite-difference time-domain (FDTD) method has been applied to the calculation of the phonon band structure of two-dimensional (2D) phononic crystals, consisting of metal cylinders placed periodically in liquid. By comparing several combinations of materials for metal cylinder and liquid, we analyze the dependence of the band structures on sound speed and density of liquid media. Moreover, the negative refraction of the acoustic waves is observed at the interfaces between phononic crystal slab and the liquid. We find that an acoustic“lens effect”with the slab appears due to the negative refractions. The relationship between the focal intensity in the lens effect and the band structure is discussed.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama1349-6115432009Dispersion Models and Electromagnetic FDTD Analyses of
Nanostructured Metamaterials using Parallel Computer815ENChiekoTotsujiKenjiTsurutaHirooTotsujiMetamaterial which has negative permittivity and permeability is investigated via computer simulations. Effects of the nanostructure on dielectric and magnetic properties of the material are taken into account by introducing the Drude-Lorentz model in the materials dispersion. We include multi-band process in the dielectric response in order to reproduce accurately experimental values of bulk Au thin film. Size effect on the dispersion is examined by comparing the model with that of a noble metal particle. Based on the dispersion model constructed, we analyze the electromagnetic response of nanostructured metamaterials to evanescent waves at microwave and optical frequencies via finite-difference time-domain simulatioins on parallel computer. A re- focusing and an amplification of the evanescent waves propagating through a metamaterial, consisting of metal
slab/vacuum stacking, is demonstrated for the frequencies of 30GHz and 744THz.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama1349-6115432009Crystal rotation behavior with fatigue crack propagation in copper films17ENKenichiShimizuTashiyukiToriiKokiIshidaUsing a fatigue testing method by which fatigue cracks can be initiated and propagated in a film adhered to cover an elliptical through-hole in a base plate subjected to push-pull cyclic loads, annealed copper films with the thickness of 100μm and those reduced the thickness from the 100μm to 50μm by an electro-polishing were fatigued under a constant stress amplitude with a stress ratio of zero. The crystal rotation behavior with the fatigue crack propagation was investigated by measuring the crystal orientation around the fatigue crack initiated from the notch root before and after fatigue testing, using EBSD (Electron Back-scatter Diffraction) method. Then, the change of crystal orientation with fatigue testing was evaluated quantitatively from the misorientation between the crystal orientation matrix on the same point obtained before and after fatigue testing. As a result, the angle of the crystal rotation obtained from the region showing the high fatigue crack propagation rate was larger than that obtained from the region showing the low fatigue crack propagation rate for the film with the thickness of 100μm, while the fatigue crack propagated faster in the film with the thickness of 50μm than that with the thickness of 100μm regardless of the small crystal rotation angles with the fatigue testing for the film with the thickness of 50μm.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00712521991Mesh Generation for Convex 3-Dimensional Domain123133ENTakeoTaniguchiChikashiOhtaThe aim of this investigation is the proposal of 3D mesh generation method based on the Delaunay triangulation. The method is valid for the finite element modelling of any convex 3D domain into tetrahedra with optimum geometrical configuration. This paper includes the mathematical background of the mesh generation method, its detail, proposal of some efficient tools for faster and more rigorous computations, and some examples of the mesh generation.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00712521991Nested Dissection Method on Transputer115122ENTakeoTaniguchiNested dissection method is an elimination method for a set of linear algebraic equations with minimum fillins. Physically it divides a domain into four subdomains, and each subdomain is again divided into four. This procedure is repeated till all nodes are included in some subdomains. Using this characteristic, the authors examine the efficiency of the method on the transputer.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00712521991Analysis of Superconducting Microstructures: Critical Temperature of Two-Dimensional Structures95113ENHirooTotsujiCritical temperatures of two-dimensional microstructures with superconducting proximity effect in the dirty limit are evaluated for various geometrical constructions. As a numerical method, the finite element method is applied. Guidelines in estimating critical temperatures are given for the case where the decay of superconducting order parameter is either sufficiently slow or fast in comparison with the scale length of the structure.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00712521991Analysis of Superconducting Microstructures: Formulation8193ENHirooTotsujiNumerical methods for the analysis of the proximity effect in superconducting microstructures in the dirty limit are formulated on the basis of the finite element method. One- and two-dimensional cases are considered and third order Hermite shape functions are used. The results are also applicable to investigations of electronic states in semiconductor superlattice structures.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00712521991A Basic Study on Nonlinear Sound Propagation by Finite Element Simulation6980ENYukioKagawaA finite element approach to the calculation of nonlinear sound propagation is proposed. Under the assumption of a weak nonlinearity, a linearized one-dimensional equation is considered. The equation is discretized in space, and is then solved for time by using Newmark-β integration scheme, in which a numerical damping is devised. Some numerical demonstrations are made for the nonlinear sound propagation of a single-shot pulse in air. It is shown that the shock wave propagation is stably and accurately simulated by the introduction of the numerical damping.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00712521991A Procedure for Settling Multi-Criteria Problem by a Small Group of Decision Makers5567ENYoshimasaKameyamaHayatoshiSayamaKazuhikoSuzukiAHP can handle decision-making problems involving several criteria when some of these are difficult or impossible to compare other than numerically. When a small group of decision makers settle the multi-criteria problem by AHP, the members of group could not often reach an agreement with hierarchic structure involving objectives, criteria, sub-criteria and alternatives because they have different
positions, interests, and opinions. Further, the members have different importances for criteria and sub-criteria, and have dissimilar preferences for alternatives. In this article, we reveal the troubleness of AHP in case of being used by a small group of decision makers. Moreover, we proposed a procedure of AHP which the members of group could easily agree with the structure of problem and the weights of criteria etc.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00712521991Prediction of Transient and Steady Turbulent Free Subsonic Air Jets3954ENEijiTomitaYoshisukeHamamotoVelocity distributions and related parameters of transient and steady, turbulent air jets issuing under atmospheric conditions at Mach 0.14, 0.33 and 0.5 have been predicted using Navier-Stokes(N-S) equations for compressible flow and incompressible flow independently with the k-ε model. The closeness and consistence of the results predicted by the N-S equations for compressible and incompressible flows as well as with relevant measurement or similar prediction show that the incompressible flow assumption for at least some subsonic gas jets issuing at velocities higher than Mach 0.3, the general limit for incompressible fluid flow, can be reasonably accurate particularly in the main fully developed flow region. This suggests that the divergence term in source terms of the momentum, turbulence energy and its dissipation rate equations have negligible effects for some seemingly compressible high speed, subsonic free gas jets. The computation time is reduced by at least 18 % when incompressible flow assumption is used.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00712521991Numerical Calculation of a Transient Methane Gas Jet Discharging into Quiescent Atmosphere at Mach One2538ENEijiTomiｔaYoshisukeHamamotoA suddenly started cold methane gas jet issuing from a 1 mm diameter orifice into still air at Mach one has been predicted using the two-equation, high Reynolds number version of k-ε turbulence model and SIMPLE algorithm which employs so called primitive variables and a hybrid scheme for treating combined diffusion and convection. Global trends of predicted radial distributions of velocity, temperature, methane concentration in the steady rear part of the transient jet and axial jet tip penetration compare reasonably well with universal profiles representing measurement for the steady jet particularly in the fully developed turbulent core and semi-empirical relation for the transient jet respectively. The prediction scheme has shown reasonably good accuracy especially in prediction of main flow parameters of a transient, high speed compressible gas jet issuing into a dissimilar surrounding gas(binary gas mixture jet).No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00712421990Parallel Skyline Method using Two Dimensional Array99112ENTakeoTaniguchiThis paper presents an effective solver for a large sparse set of linear algebraic equations, which appears at the application of the finite element and the finite difference methods in engineering field. Proposed method is a family of SKYLINE METHOD, and for faster computation on the vector processors the original skyline is modified with respect to following three items; the use of inner products of matrix operations, the removal of unnecessary numerical operations and the introduction of two-dimensional array for storing the data of coefficient matrix.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00712521991Fatigue Strength of Age-Hardened Al-Zn Alloys under Repeated Tensile Loading1723ENAkiraSakakibaraTerutoKanadaniToshiakiKaneedaNorioHosokawaEffect of the soft surface layer that was formed on low temperature aging of Al-Zn alloy on fatigue strength was studied under repeated tensile loading. Vickers microhardness test revealed that there existed less hardened region in the vicinity of grain boundary and surface, and that the region extends 50 to 100μm from the surface inward. From the plot of the stress amplitude against the number of cycles to failure, it is concluded that the presence of less hardened surface layer strengthens fatigue resistance of the age hardened Al-Zn alloys containing 8 to 16mass % Zn under the repeated tensile loading.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00712421990Functional Testing of an ALU8998ENTokumiYokohiraThis paper considers a test set for an ALU with look ahead carry generators(LCGs). The ALU is logically partitioned into two groups of blocks, the group of one-bit operation units and LCG group. Each group is tested in parallel and exhaustively, independent of the other. And an easily testable design is applied to several blocks for decreasing the number of the input combinations of them. Under the easily testable design, a minimum test set for each group is generated, and the upper and lower bounds for
a minimum test for the ALU are derived. The difference of the lower and upper bounds is not large, and a test set whose number of test vectors is equal to the upper bound can be easily obtained as the union of minimum test sets for two groups. Hence, the union can be used as a complete and practical test set for the ALU.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00712521991X-ray Topographs of Strain Field Induced by Locally Ion-Plated Films on Si Substrates915ENMasatoMikuniMoritakaHidaNorihideNishidaAkiraSakakibaraMasuoYamadaStrains induced in the Si substrates by TiN film were observed with X-ray topography. The image of the sample with TiN film 0.45μm thick was like that of a dislocation loop observed with transmission electron microscope. The images of the samples with TiN films 1.65, and 1.9μm thick were different; blackening spreaded in the <112> and <110> direction from the ring contrast in shape of four-lobed rosette pattern. Spreading extended 1.6 times longer than the radius of the ring contrast along the <112> direction. The strain field extended 0.1μm in depth from the top surface where TiN was plated. From the topographs of bent Si beam, it was found that the blackness was almost proportional to the strain. The strains induced by TiN film locally ion-plated were smaller than those observed
previously when TiN was ion-plated on the whole top surface of the substrate. Fine structures were observed in the topographs which could not be explained by the kinematical theory.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00712421990Mean Time Between Failure of Ring Arbiter with Requests Differing in Incidences7987ENYoichiroSatoIn asynchronous arbiters, failures may happen, caused by metastable operations. The purpose of this study is to derive a formula to estimate such failures in a ring arbiter as mean time between failures (MTBF), under the condition that incidences of requests issued in all devices are different from each other. The operation of the arbiter is formularized by a markov chain. This chain is used to decide the probability at which each of possible failures contributes to MTBF. The sum of such probabilities gives the MTBF which can be represented as a sum of a finite number of terms. As an example, MTBF of a ring arbiter composed of 3 cells is shown.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00712421990Movement of Sand around Revetment under Water Pressure Variation6778ENHiroshiNagoShiroMaenoMany hydraulic structures are damaged by under flood flow and storm waves year after year. Many cases of dike and breakwater failure are caused by the suck out of sand from behind the revetment. This type of failure will be in close relation to the dynamic behavior of sand bed around the revetment. In this paper, from this point of view, we investigated the basic characteristics of such sand movement by small model tests and tried to explain the hydro- and soil-mechanical mechanism of this phenomenon theoretically.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00712521991Mechanical Characteristics of Cast Ti Fiber-Reinforced Mg Composite18ENHiroyukiOkadaMoritakaHidaAkiraSakakibaraYoshitoTakemotoTensile strength and elongation of cast magnesium reinforced with titanium fiber were measured by tensile test. The pull-out test of a titanium rod partially embedded in a magnesium matrix was performed to evaluate interfacial bonding strength between magnesium and titanium. It was found that when the fiber volume fraction was changed from 1% to 14%, the tensile strength was improved with increase of volume fraction, while the improvement of elongation tended to be restrained beyond the volume fraction of 10%. The interfacial strength was revealed to be strong, and this was substantiated by the scanning electron microscopy showing an excellent wettability between the titanium fiber and the magnesium matrix.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00712421990Characteristics of Errors in Open and Closed Trilateration Nets4965ENChujiMoriDistance measurements have been more and more easy and accurate to carry out, and it is expected that distance mesurements may provide rather accurate results than angle measurements. Under these circumstances, caracteritics of errors in typical trilateration nets are investigated. The nets investigated are as follows: From single row of chains to pranimetrically extended nets in figure, open and closed networks with respect to external constraint, and with and without as to internal constraint. Computations are performed by use of the method of condition equations, and behaviours of error propagation and errors of coordinates of stations in the nets are shown in case of typical nets. For example, effects for decrease in error by composing a double row of chains and by enforcing external constraints are explained.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00712511990Determining Hydraulic Properties of Multilayered Aquifers from Pumping Test Data by Parameter Estimation99109ENMakotoNishigakiYujiTakeshitaIichiroKonoIn this paper, a numerical procedure of determining hydraulic properties in multilayered aquifers are presented. From pumping test data in multilayered aquifers, the coefficient of permeability and specific storage for each aquifer are determined by using a combination of finite element analysis and nonlinear least-squares optimization technique. This study especially points out necessity of stress-flow coupling analysis to explain the behaviors of pressure head in multilayered aquifer during pumping test. As a example, practical pumping test data were evaluate and the coefficients of permeability and specific storage of aquifers and aquitard were obtained.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00712421990Control of Microscopic Superconducting Channel by the Proximity Effect4147ENHirooTotsujiA possibility to control the microscopic superconducting
channel based on the proximity effect is theoretically shown by a simple one-dimensional analysis of de Gennes' equation for the order parameter.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00712511990The Structure of Interregional Migration in Japanese Regions : An Application of Multidimensional Scaling8998ENHirofumiAbeMultidimensional scaling (MDS) has been used in a wide variety of research fields; psychology, political science, anthropology, marketing research, urban and regional planning, and so on. In practical terms, MDS is a statistical method to make a picture of the information in the data. It enables us to examine the "hidden structure" of a set of data. When the set of data is large, MDS is extremely useful, since it is easier and more informative to look at a picture than the data themselves. In this paper, MDS is applied to the interregional migration data of Japanese regions for the years 1960-85. Findings show that the two-dimensional configuration of regions estimated by MDS generally corresponds with the geographical locations of regions, and the structure of interregional migration was very stable over the study years 1960-85. It is also suggested that MDS is a useful tool to identify the relationships between regions using the spatial interaction data.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00712421990Basic Characteristics of Microvibration on the Skin Surface3140ENHisaoOkaTatsumaYamamotoA small vibration on the body surface is expected to apply to a clinical examination of the autonomic nervous system. The vibration cannot be found by the naked eyes. It is called a microvibration (MV) or a minor tremor (MT). It is not cleared out why and how the MV occurs, but many papers about its occurrence and clinical application have been published. In this study, the typical spectrum of MV and the various causes of MV occurrence are studied. The relationships of MV with heart rate, muscle contraction and MV are discussed. The power spectrum of MV is obtained by using an autoregressive model.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00712511990Optimal Pricing and Planning of Urban Expressway System7187ENA transportation planning way of approach is applied to optimal pricing and planning of urban expressway network. Two kinds of network are investigated ; four radials with one ring system and four radials with two rings system. The model is composed of three submodels ; road systell, trip generation-attraction and traffic diversion. Some iaplicative aspects are shown of the optimal solutions that maximize the aggregate number of the trips diverted to expressway under constraints ; equilibrium of revenue and expenditure and traffic capacity constraint. (1) traffic flow has the peaks at junctions on radial expressway that are adjusted to be equal to the traffic capacity. (2) two rings system realizes the larger aggregate number of diverted trips by lower toll rate than one ring system does. (3) well-located second ring has a remarkable effect on improvement in accessibility to expressway and (4) some parameters in the model have curious effects on the optimal system.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00712421990Film Continuity Problem on Journal Bearing Design1730ENTadatakaKonishiMitsuruBabaPressure distribution has been measured and analyzed to clarify the fundamental characteristics of "continuous oil-film" formed in a transparent journal bearing, into which oil in general use is supplied. Measured pressure mostly shows quasi-Sommerfeld distribution, which is characterized by downstream shift of pressure profile and underdevelopment of pressure trough compared with Sommerfeld distribution for perfect oil-film. Sommerfeld distribution is approximately observed only under limited
conditions : low eccentricity and low speed. Quasi-Sommerfeld state is rather common in "continuous oil-film", unruptured film formed by using practical lubricants, than Sommerfeld state. Continuous oil-film is accompanied by fine bubbles and is controlled by the growing up or down of the bubbles.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00712511990Pumping Test for Multilayered Aquifers5969ENIichiroKohnoMakotoNishigakiIn this paper, we propose a method to determine the coefficients of permeability of the unconfined aquifer consisted of two different permeability layers. With mixing the conventional pumping test and falling head permeability test, the coefficients of permeabilitiy k(1) and k(2) were obtained. The validity of the proposed method is investigated by using the numerical simulation. As the results, it becomes apparent that the proposed method is applicable to real hydarulic problems.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00712421990Aging in Dilute Al-Si Alloys1116ENAkiraSakakibaraTerutoKanadaniAging behavior of Al-0.23mass % Si alloy was studied by measurements of elecrical resistivity. Resistvity maximum was observed in the aging curves at 273K after quenching from various temperatures. Appearance of maximum and its dependence on the quenching temperature were attributed to the formation of GP zones. Even in a more dilute alloy as 0.01mass % Si, the maximum of resistivity was also recognized.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00712511990Superconductivity Proximity Effect in Inhomogeneous Media5157ENHirooTotsujiThe superconductivity proximity effect in the dirty limit is revisited and equations and boundary conditions are obtained for the case of inhomogeneous media with continuously varying characteristic parameters.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00712421990Fine Particles of Ti and Ti-Mo Alloy Prepared by Gas Evaporation19ENMasayukiUmemotoYoshitoTakemotoAkiraSakakibaraMoritakaHidaFine particles of Ti-Mo alloy were prepared by evaporation. When Ti-40at % Mo alloy was evaporated on tungsten filament, fine particles of Ti contaminated with W were obtained. These particles were polyhedron in shape and 10～250nm in diameter. Average diameter and size distribution increased with pressure of argon gas (100～600 Torr). When pure Ti was placed on the Mo filament and evaporated from melt down of heated Mo filament in helium gas, fine particles of pure Ti and of Ti-Mo alloy were obtained. In this case, Ti particles were of indeterminate form and of several tens nm in diameter, and their diffraction pattern was of common α-Ti. On the other hand, composition of the Ti-Mo particles was determined to be 18at % Mo by an analysis of EDX. Structure of Ti-Mo particles could not be determined because their diameters were more than 600nm. The temperature of Mo filament, for the most part, was about 1800℃, and there pure Ti particles were produced. The temperature of the fused part of the filament was locally higher than 2600℃, and there Ti-Mo particles were produced. Fine structures of contact region among some Ti particles were observed with HRTEM.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00712511990Second Harmonic Detection of Atmospheric Trace Gases with a Train-Pulse Driven Lead-Salt Tunable Diode Laser for an Operation at Peltier Cooling Temperature3750ENMoncefBouzidiRyujiKogaOsamiWadaNaokiKagawaXuHaiMegumiKosakaHiroyaSanoIs proposed a tunable diode laser absorption spectrometer system which employs a pulsed current to drive the diode laser still implementing a second-harmonic detection methods enhancing a signal to noise up to 104 times that the case without it. This system affords the lead-salt diode laser a higher operating temperature which allows a more compact deep cooling system. A principle is based on employing a gated integrator between the preamplifier and the lock-in amplifier. Investigations are made on the optimum selection of the gating aperture time interval as determined by response time of the infrared detector and the pulse width of the laser driving current.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00712411989Numerical Simulation of Multicrack Propagation Behaviour in Steel Structure135152ENTakeoTaniguhiTsuyoshiSuetsuguThis paper describes the numerical simulation method of the multi-crack propagation behaviour which appear in a part of civil engineering structures with complex geometrical configuration like steel bridges. Proposed method can treat the interaction of several cracks which locate in a short distance each other, and the process of their growth can be grasped. The method is based on the finite element method, and the linear fracture mechanics is assumed. Proposed method includes following tools for the simulation of the crack propagation behaviour: Automatic Mesh Generators for 3-D, 2-D structural analysis, and 2-D crack propagation analysis, Multi-level Structural Analysis Technique, Estimation Method of the crack growth and the angle of cracks and the modelling method of traffic loadings. The validity of the method is investigated by comparing the result to the experimental one.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00712511990Preparation of ZnO Films by Activated Reactive Evaporation Method2335ENYoshinariMiuraJunTakadaAkiyoshiOsakaToshioKawamuraZinc oxide films were prepared on silica glass substrates by the use of an r.f. activated reactive evaporation (ARE) method, and were examined by X-ray diffraction (XRD) and scanning electron micrograph (SEM). XRD measurements indicate that the films were c-axis oriented and that an r.f. plasma of Zn and O was necessary for the ZnO film deposition. Substrate temperature, oxygen gas pressure, evaporation rate, r.f. power and inlet position of oxygen gas effect the c-axis orientation, the growth rate and the microstructure of the films. Optimum conditions for a dense film with a fine texture of the surface and having good crystallinity were as follows: the substrate temperature;400℃, the evaporation rate;5.0(A)/s, the oxygen pressure;2.0x10(-4) Torr, the r.f. power;150 to 200W, and the oxygen gas inlet near the substrate. For the film prepared under the optimum conditions, the standard deviation σ of the rocking curve for the (002) diffraction was 1.9deg, smaller than that of the film prepared by using an r.f. sputtering method.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00712411989Trends in the Regional Structure of Manufacturing Industries in Japan115133ENHirofumiAbeThe rapid economic growth of Japan in the postwar period has brought about the over-concentration of activities in a few large cities, and local regions have been losing their economic vitality due to the regional differentials and the population loss. Regional development planning in Japan has sought to achieve a balanced growth of the nation through the development of industries in local regions. This paper aims to examine the regional structure of manufacturing industries in the postwar period and to
identify its current problems. Three methods, namely the analysis of coefficient of variation, the rateshare analysis and the shift-share analysis are applied using employment data of manufacturing industries for the years 1955 to 1985. Findings show that while the employment of manufacturing industries has been markedly decentralized from metropolitan to local regions, the disparities in growth rates still exist among regions.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00712511990Effect of Quenching Condition on the Growth of GP Zones in Al-lmass % Ag Alloy1521ENAkiraSakakibaraTerutoKanadaniAging of Al-lmass % Ag alloy at 273K after quenching under various conditions was studied by measurement of electrical resistivity. Scattering of the quasi-equilibrium value of resistivity (p(e)) was not random but closely related to the as-quenched value (p(o)); P(e) increased with increasing p(o)' When the quenching temperature (T(q)) was lower than or equal to 773K, the state at p(e) was controlled substantially by the concentration of quenched vacancy. On the other hand, when T(q)>823K, GP zones formed during quenching played an important role, instead of quenched vacancies, in determining the state.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00712411989Determination of Unsaturated Soil Hydraulic Properties by Transient Flow Experiments and Parameter Estimation107114ENIichiroKohnoMakotoNishigakiYujiTakeshitaThe numerical feasibility of determining soil water retention and hydraulic conductivity functions simultaneously from one-dimensional transient flow experiments in the laboratory by parameter estimation method is evaluated. Soil hydraulic properties are assumed to be represented by van Genuchten's closed-form expressions involving two unknown parameters: coefficients α and n . These parameters are evaluated by nonlinear least-squares fitting of predicted and observed pressure head with time. Gravity drainage experiments are performed for Toyoura standard sand to evaluate the adequacy of this proposed method.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00712411989Propagation Characteristics of Superlattice Potentials and their Optimization93105ENHirooTotsujiTerukiHatataniPropagation of charged carriers in semiconductor
superlattices is analyzed on the basis of the effective mass approximation with appropriate boundary conditions at heterojunctions taken into account. Applying the finite element method, clarified are the effects of details of the potential profile, such as linear and smooth gradings and random fluctuations, on characteristics of superlattices which are expected to work as collector barriers and energy filters in electronic devices.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00712411989Analysis of the Radiation Characteristics of a Primary-Feed Waveguide in a Quasi-Optical Antenna for Circular TE(On) Mode8192ENOsamiWadaAre calculated the radiation characteristics of two types of primary-feed waveguides of millimeter wave quasi-optical antennas, which transform circular TE(On) mode into a linearly polarized beam. These antennas are utilized for heating and diagnostics of fusion plasma. Analysis is based on the Huygens-Fresnel principle, which takes the diffraction effect into account. For Convenience in analysis, a feed waveguide is divided into two sections, an uniform waveguide section and a visor section. Assuming that the diameter of the waveguide is several times as large as the wavelength and that the structure of the visor is open, the radiation field is approximated by superposition of direct radiation, and first and second reflection on the visor. Numerical results are presented and compared with experimental results. In these types of waveguides, the shadow section on the visor has a great influence on the radiation field. The results of calculation show that the length of the visor should be longer than that obtained by the geometrical optics, and the longer visor reduces the side-lobe level in the direction of the waveguide axis. The results agree well with those in experiments.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00712511990A Method of Cubic Object Feature Extraction113ENTsutomuWadaToshiroNoritsuguHow to reduce and simplify the calculation for image recognition is a very attractive and important issue in order to realize the real time control of a robot based on the image recognition results. This paper describes a method of extracting 2 - dimensional geometrical features of cubic objects based on the normal vector distributions from the visual information obtained with the laser range finder to reduce the calculation of the image recognition. In this research a laser beam is scanned in the horizontal plane to which the cubic objects stand vertically and the laser spot is detected with a TV camera every sampling time. These spots make an intermittent locus which includes some special lines corresponding to the cubic objects. To extract the features of the cubic objects, we utilize the normal vectors formed on the locus. If some normal vectors distribute in the same direction and the origin of the normal vectors are very close to their neighbor's, these normal vectors can be classified into the same class, -the straight line class. Because the normal vectors on the neighbor surfaces of the cubic objects are vertical to each other, we use this property to determine the pair of straight lines which belong to the cubic objects. Making the histogram based on the normal vectors with the same direction, we obtain the peaks which are supported by the points on the cubic object surfaces. Then, the points can be extracted from the set of points on the whole locus inversely according to the relations with the peaks and the features of the cubic object can be extracted by applying method of least square to these extracted points. The experiments proved the availability of the proposed processing algorithm.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00712411989Measurement of Microvibration on the Skin Surface7380ENHisaoOkaYoshitakeYamamotoTatsumaYamamotoThere is a small vibration which goes undetected by the naked eyes. It is called a microvibration (MV) or a minor tremor (MT). The MV on the body surface is expected to apply to a clinical examination of the autonomic nervous system. It is not cleared why and how the MV occurs, but there are many papers about its occurrence and clinical
application. In this study, MV measuring system, its estimation and basic characteristics are examined. The difference between head MV and thenar MV, individual MV and diurnal and seasonal change are discussed. The power spectrum of MV is obtained using an autoregressive model.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00712321989On Robust Incomplete Choleski-Conjugate Gradient Method And Its Modification4555ENTakeoTaniguchiKohjiFujiwaraThis paper includes a solver for a large sparse set of linear algebraic equations which are obtained by the application of the finite element method to static structural problems. Proposed method is a modification of Robust Incomplete Choleski-Conjugate Gradient Method, which belongs to Preconditioned Conjugate Gradient Method suitable for supercomputers. Through a number of numerical experiments the authors show that Robust Incomplete Choleski-Conjugate Gradient Method sometimes fails in to obtain the solutions, secondly they clarify the reason of the failures from the theoretical viewpoint, and finally they propose a modification of the robust method by the introduction of the theoretical result. Proposed method is as effective as the original, and it can overcome the demerit of Robust Method which is clarified through numerical experiments.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00712321989Flow of Rarefied Vapour past a Liquid Sphere3344ENKyojiYamamotoThis paper deals with the low Mach numbers flow of a rarefied vapour past a liquid sphere accompanied with condensation and evaporation at its surface. The linearized Bhatnager-Gross-Krook(B-G-K} equation is used for the analysis, and from it the integral equations of the density, temperature and flow velocities are derived. These integral equations are solved numerically over a wide range of the Knudsen number covering from the slip flow to the nearly free molecular flow. The drag on the sphere is also calculated and is compared with that of previous work.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00712411989Measurement of Emotional Response by Similarity in Patterns of Galvanic Skin Reflex6372ENYoshitakeYamamotoHisaoOkaTatsumaYamamotoThere is no doubt that many people feel the peace of mind or the pleasures of senses in appreciating music. But the estimation of the effect is very difficult and the objective estimation can be hardly done. This study proposed the objective estimating method of human emotion utilizing galvanic skin reflex (GSR) which reflects a human psychological activity. In this method, not by individual response, but by the series of response and pattern of appearance of GSR, the emotional response under appreciating music was investigated. In the case of appreciation of the same classic music to several subjects, the individual GSR responses are random and remarkable characteristic could not be find on the results. However, on the patterns of appearance of GSR, the patterns obtaining from the same generation are much similar each other and the patterns obtaining from different generation are less similar. It was cleared that the same music gave different effect on different generations.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00712321989An Applicability of Aggregate and Disaggregate Estimations to Mode Choice by Inter-regional Occupational Person Trips2132ENDiversion model and disaggregate behavioral model of logit type are adopted as aggregate and disaggregate estimates, respectively. Diversion model is assumed as a binary choice process including diversion ratio function at each step in the process. Diversion ratio is assumed as a function of generalized-travel-time ratio. The function is identified with each of the two steps of diversion; diverson from rail and bus to car at first and from the rest undiverted to bus at second. The data used are those on inter-regional occupational person trips. Each function are found enough and/or critically significant in the statistical sense. At the begginning, sixteen characteristics variables are enrolled in disaggregate model, which are identified by use of the above data. Six variables are reached finally and are all reasonable. A brief comparison of goodness of fit to the data are made between two models.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00712411989The Diffusion of Sodium Ions into Tin Oxide Thin Films from Glass Substrates5361ENAkiyoshiOsakaKiichiOdaJunTakadaYoshinariMiuraElectrical resistance and X-ray photoelectron depth profile analysis are studied for antimony doped tin oxide films developed on silica, alkali-free and sodalime slide glass substrates. The sodium ions diffused from the substrates to the films prevented the crystal growth of rutile type tin oxide in the film, resulting in the high electrical resistance. A diffusion layer has been detected for each film with diffuse profiles of multi valent cations (Sn, Si or Ca) at the interface of the tin oxide film and substrate. A greater amount of sodium atoms have been detected in the film developed on the soda-lime glass while almost no sodium atoms have been found in those on the other substrates. This can be explained by the diffusion of the sodium ions in the substrate due to a drastic hydronium-sodium exchange mechanism under highly acidic conditions during the dipping and drying processes.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00712621992Preparation of Mullite Dispersed Silica Ceramics through Sol-Gel Processing6167ENAkiyoshiOsakaTokuroNanbaJunTakadaYoshinariMiuraMullite-dispersed silica ceramics were prepared through sol-gel processing by the use of tetraethoxy silane, aluminium nitrate and aluminium isopropoxide as the Si and Al sources where HCl and HN0(3) were the catalyst. Effect of the starting materials, solvents and catalysts was examined on the gelation time or temperature of mullite precipitation. Apparent activation energy of gelation ranged from 80 to 95kJ/mol. The presence of AI in the sols elongated the gelling time suggesting the formation of chelate bonds between AI and Si-OR or Si-OH bonds.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00712321989A Design Method for Pin Holding Type Jig919ENHirokazuOsakiMasaakiMatsudaMulti-item flexible manufacturing systems have been spread to correspond the short life-cycle and the diversification of products. Part handling plays an important role to operate multi-functional robot efficiently in these systems, and many jigs are widely used to hold a part. They should be exchanged at once according to changing products. In this paper, we propose a pin jig which holds a part with two pins, and design method of the position, length and diameter of those pins for a cylindrical part. This jig has the following characteristics. As a surface of the jig is inclined to use gravity, the part can be fixed without any external forces. Therefore the structure of jig becomes simple, and loading and unloading of a part becomes easy for a robot hand.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00712411989An Expert System for the Scheduling of a Flexible Assembly Line for Multi Item Products2539ENYasuhiroKajiharaHirokazuOsakiAn expert system, in which preconditions and rules are expressed in logical formulas, is developed to support the scheduling of an automated job shop type multi-item assembly line. This system has the foIIowing characteristics to apply any case of schedulings: (1)Forward scheduling orbackward scheduling can be made. (2)The criterion on the input order of products, the dispatching process at each assembly station, and the selection of products from a buffer can be selected from several priority criteria. (3)Layout, number and velocity of vehicles, and the capacity of each buffer can be changed.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00712411989Fundamental Study on Electrical Discharge Machining1324ENYoshiyukiUnoToshikatsuNakajimaOsamuEndoThe generation mechanism of crater in electrical discharge machining is analyzed with a single pulse discharge device for alloy tool steel, black alumina ceramics, cermet and cemented carbide, investigating the gap voltage, the discharge current, the shape of crater, the wear of electrode and so on. The experimental analysis makes it clear that the shape of crater has a characteristic feature for the kind of workpiece. The shape of electrode, which changes with the wear by an electric spark, has a significant effect on the shape of crater. The diameter and the depth of crater have a close relation to the discharge energy for alloy tool steel, black alumina ceramics and cermet, while those for cemented carbide are related to the discharge current. The shape factor which is the ratio of the depth to the diameter of crater is different for the work material.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00712321989Wettability and Supercooling Phenomena of Ga18ENHidetoKamiyabuAkiraSakakibaraHironobuMaedaMoritakaHidaSurface tension (γ(L)) and contact angle (θ) of gallium related to wettability on Teflon and other substrates (Al(2)O(3), SiO(2), glass, graphite, BN, AI, Ni, As etc.) were investigated. The values of Teflon were 0.70(6)N/m and 158° in pure argon atmosphere, and the ones of other substrates were listed in a table in this text. We were interested especially in the relative values, γ(L)'s, on the substrates as compared with γ(L) on Teflon substrate. Liquid Ga showed spreading wetting on pure Ni metal and adhesional wetting on Al (supposed to be covered by A1(2)O(3)) and on metallic polycrystal As. Surface tension of Ga was remarkably decreased by a kind of oxide contamination
due to oxygen in air. The surface layer coated by the contamination was of amorphous state nearly same as liquid Ga. The amorphous coat caused liquid Ga rather high supercooling of △T~35K. It seems that the contamination layer (oxide fi1m) smeared the crystal nucleation sites on the free surface of liquid GaNo potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00712311988Plasma Oscillation in Semiconductor Superlattice Structure6982ENHirooTotsujiThe statistical properties of two-dimensional systems of charges in semiconductor superlattices are analyzed and the dispersion relation of the plasma oscillation is calculated. The possibility to excite these oscillations by applying the electric field parallel to the structure is discussed.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00712311988Determination of Electrical Parameters for Skin during Galvanic Skin Reflex from Continuous Measurement6168ENYoshitakeYamamotoTatsumaYamamotoSkin impedance satisfies the Cole-Cole arc's law. The change of skin impedance during GSR (Galvanic Skin Reflex) can be expressed by the change of equivalent parallel resistance approximately. Using these characteristics, the complicated change of skin impedance during GSR can be determined continuously from the measurement value in one frequency point.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00712411989Effects of Drive System Lubricant Additives upon Rolling Fatigue of Carburized and Hardened Steel Rollers112ENAkiraYoshidaYujiOhueMasahiroFujiiTo clarify the effects of a drive system lubricant additive upon rolling fatigue of rollers manufactured from carburized and hardened steel, three types of oil were used as lubricants: one mineral base oil and the other two mineral base oils to which an S-P additive package and ATF additive package were added, respectively. These specimens were tested for sliding/rolling fatigue and examined for failure on the surface, rolling fatigue strength, and other properties. Roller surface temperatures and inter-roller frictional coefficients were found scarcely affected by the type of oil used. Irrespective of the difference in oil type, failure on the surface was found to be entirely spalling attributable to cracks generated in the subsurface. The depth at which spalling cracks had taken place was found nearly coincident with the depth at which a ratio of reversing orthogonal shear stress to hardness had amplitude A(Tyz/Hv) maximized. These depths were larger as Hertz stress became more prominent. Nevertheless, they were found hardly affected by the type of oil. Although rolling fatigue strength did not show a significant difference dependent upon the type of oil, it may be said that fatigue life would be somewhat negatively affected by an extreme pressure coated film with a content of sulfur and phosphorus.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00712311988Transient Displacement Response to Pulse Excitations on Periodontal Tissues4960ENHisaoOkaTatsumaYamamotoIn the field of dental study it is most fundamental and necessary to estimate the condition of periodontium. In order to examine a mechanical characteristics of periodontium, the theoretical displacement response to periodontal mechanical model (three elements model) are strictly solved in case of some pulse excitations. Impact excitations (rectangular, triangular and half-cycle sine pulse) are given in physical and mathematical definitions and complete solutions to the impact excitations are provided. The triangular pulse excitation which is obtained by means of a fracture of pencil-lead is most suitable. The mechanical parameters of periodontium are given using this input excitation. This is experimentally confirmed by artificial tooth model. The obtained mechanical characteristic of the periodontal tissues can be applied to clinical diagnosis.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00712821994Chemical States of Fluorine Atoms and Laser-Induced Crystallization in rf-Sputtered Thin Films of Amorphous Lead Fluorosilicate7784ENAkiyoshiOsakaYoshinariMiuraAmorphous films of lead oxyfluorosilicate were prepared with a rf-sputtering technique, and the distribution profiles of the component elements and chemical states of the fluoride ions were analyzed with an X-ray photoelectron spectrometer. Si atoms with an expanded coordination, O(4)Si-F, were present near the surface, and O(3)Si-F units were present in the deeper part of the films. Electrical resistance indicated transition to a
conduction state for the films containing fluoride ions, while the films were crystallized to precipitate low quartz by the irradiation of He-Ne laser of 3 mW up to 1 sec.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00712821994A Study on the Elasto-plastical Constitutive Equation for Unsaturated Soil5975ENMakotoNishigakiIichiroKohnoIn this paper, first, an elasto-plastic consitituve equation for unsaturated soil was developed by considering of the basically behavior of unsaturated soil. Second, the results of a number of triaxial test and a set of rigid
foundation model tests were simulated by using this constitutive equation, the agreement between observed and computed results was satisfactory and confirms the possibilities of this constitutive equation.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00712311988Amorphous Oxides Prepared from Organometallic Compounds Part2. Structure Evolution in Sodium Borosilicate Gels3948ENAkiyoshiOsakaYoshinariMiuraKatsuakiTakahashiSodium borosilicate gels of compositions similar to that of Vycor(R) glass like 80SiO(2).15B(2)O(3).5Na(2)O (wt%) were prepared from hydrolysis and polycondensation of metal alkoxides under the HCl catalysis. Variation of specific surface area and porosity with temperature indicated that closed pores were opened below 400℃, and collapsed above 450℃ after the porosity reached a maximum value around 450℃. The structural evolution was examined due to IR spectra and a phase separation in the gels was observed. The solubility of the gels into 1N-HCl was studied as a function of the treatment temperature.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00712821994Note on the Piezoelectric Constant of PbZrO(3)-PbTiO(3)(PZT)5358ENChiekoTotsujiOne of the best known solid solution of perovskites is the PbTiO(3)-PbZrO(3) system which is usually abbreviated as PZT. In the phase diagram of this system, there is a drastic phase change from tetragonal to rhombohedral at the molar ratio around 50:50. The PZT crystals are widely used as a practical piezoelectric material because of its very strong piezoelectric effect near this morphotropic phase boundary. We try to explain this anomaly in piezoelectric constant by a phenomenological theory.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00712821994Numerical Simulation of Quantum Systems -Dynamics of Electrons in Microstructures-4552ENHirooTotsujiSeijiHashimotoShigetoshiNaraDifficulties in simulating systems composed of classical and quantum particles lie in the treatment of the many-body interactions between quantum particles and the geometrical variety of configurations of classical particles. In order to overcome these difficulties, we have developed some numerical methods and applied them to simple cases. As for stationary states, the finite element method provides us with sufficient geometrical freedom.
Combined with the Kohn-Sham equation based on the density
functional theory, this method virtually satisfies our requirement. In order to investigate time-dependent phenomena, we apply the time-dependent Kohn-Sham equation. Adopting the finite difference method, we are able to follow the development of quantum many-body system. As an example, we estimate the effects of the potential height, the electric field, and many-body interactions in some transition processes in quantum wells coupled by a tunneling barrier. This example is important in itself in relation to semiconductor superlattices and also serves as a benchmark for quantum simulations, variety of geometry
corresponding to that of classical particles.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00712311988Amorphous Oxides Prepared from Organometallic Compounds Part 1. Preparation of Sodium Borosilicate Gels3138ENYoshinariMiuraAkiyoshiOsakaKatsuakiTakahashiSodium borosilicate gels of compositions similar to that of Vycor(R) glass like 80SiO(2).15B(2)O(3).5Na(2)O(wt%) were prepared from hydrolysis and polycondensation of tetraethyl orthosilicate, trimethyl borate, and sodium methylate under the HCl catalysis. Variation of the gelation time is examined as a function of the mixing ratio of the starting materials and the catalyst. The thermal behavior of the gels has been discussed on the basis of their TG and DTA traces.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00712821994Collimation of Cerenkov-SHG Blue Light with a Parabolic Mirror3344ENMingWangAnisAhmedOsamiWadaRyujiKogaProposed here is a convenient optical system to collimate the crescent shaped blue laser beam radiated from a Cerenkov SHG in channel waveguide configuration. This collimation system is consisted of a parabolic mirror and has a very large tolerance to the mirror displacement. The anisotropy of the nonlinear crystal on which the waveguide is fabricated has been taken into account. The optimum mirror location is given to obtain a collimated blue laser beam with an aberration less than 0.07λ. By using an objective lens, the collimated beam can be focused down to a thin beam with the spot size less than 1μm.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00712821994Cyclone Dust Collector with a Perforated Internal Rotating Cylinder2131ENKyojiYamamotoAn experimental investigation has been made of the cyclone dust collector with a perforated internal rotating cylinder. The size of the rotating cylinder is of 0.5D, where D is the diameter of the cyclone body, and is the same size as the outlet tube. The dust collection efficiency as well as the pressure loss has been measured when the inlet flow speed is 9 ~ 21 m/s and the rotating speed of the cylinder is 37 ~ 63 m/s. The velocity and pressure distributions were also measured. It is found that the collection efficiency decreases and the pressure loss increases as the rotating speed increases. It is also shown that both the inward radial velocity and the upward vertical velocity become large as the rotating cylinder increases its speed. As a whole, the rotation of the internal cylinder makes worse performance of the cyclone dust collector.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00712311988The Study on the Evaluation of the Visual Work Using the Logistic Curve112ENMasaakiMatsudaHirokazuOsakiDisplay equipment has been used as communication media in
the factory, office, and home. In order to communicate
effectively, it is necessary to clarify the characteristics
of eye movement in the case of looking at the display. The development of Eye Camera enables us to measure eye movement during work, so that we can collect the many data of eye movement during work. In this study, we proposed a method to evaluate the visual work using the distribution of visual points in X and Y axis. The cumulative distribution is approximated by the logistic curve which shows the symmetry and kurtosis by the parameter. The proposed method was applied to the three typical display models, that is, the digital meter model, reading model, and game model. In the digital meter model, the visual points were distributed symmetrically along the meters, and the symmetry and kurtosis of the distribution varied by the arranged direction of the meter. In the reading model, the visual points were distributed nearly symmetrically and uniformly in each axis and they were moved around the character and line from the period of spectrum analysis. In the game model, the visual points moved according to the target and were distributed symmetrically in the Y axis. And whether the target moved vertically or horizontally, the kurtosis of the distribution became equal in each axis.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-0071221988Mode Choice In Interregional Occupational Person Trips6370ENThe paper is a case study mode choice in interregional occupational person trips. Disagregate behavioral model of logit type is applied to the occupational person trips from Tsuyama area in Okayama Prefecture to Osaka area. The model turned out to give asignificant explanation of the interregional mode choice characteristics. Travel time, travelling expenses and " with or wi thout heavy baggage " were found to be significant.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00712821994X-Ray Topographic Observation of Strain Generated by Thin Film (TiN) on Silicon Surface1320ENHisaoKusumotoMoritakaHidaAkiraSakakibaraNorihideNishidaYoshitoTakemotoMasuoYamadaThe strain in Si substrate induced by locally ion-plated thin film of TiN was observed by X-ray topograph (Lang technique). Circular TiN film was deposited on one side of the Si surface. In all topographs the highest blackness attributed to kinematical diffraction effect occurred at the film edge. Rosette pattern with four-lobes was observed around the film. Blackness as a whole increased with the film thickness. Strain was observed in the depth direction of substrate by limited projection method. When the slit width was narrowed, the kinematical images disappeared, and white images appeared at the film edge. All the contrast disappeared when the TiN film was completely removed in boiling HNO(3). The strain induced by the film deposition was proved to be elastic.No potential conflict of interest relevant to this article was reported.Faculty of Engineering, Okayama UniversityActa Medica Okayama0475-00712821994Clusters in Low-Concentrated Al-Mg Alloy912ENAkiraSakakibaraTerutoKanadaniK.NakagawaY.YokotaThe state above the solubility temperature of GP zones of
Al-3mass % Mg alloy, which has a tendency for precipitation and preprecipitation at low temperature, was studied by resistivity measurement. Homogenization treatment at high temperature reduced Mg atoms in the surface layer. After quenching from 623K, the specimen was annealed sequentially at various temperatures above the GP zone solvus. The stationary resistivity obtained in annealing at a temperature was the same irrespective of the starting state and increased with decreasing annealing temperature. No precipitation was observed in the annealing. The results are not in favor of the segregation of Mg atoms to the dislocation loops but of the short range
clustering.No potential conflict of interest relevant to this article was reported.