JaLCDOI 10.18926/15517
FullText URL Mem_Fac_Eng_OU_25_2_123.pdf
Author Taniguchi, Takeo| Ohta, Chikashi|
Abstract The 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.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1991-03-28
Volume volume25
Issue issue2
Start Page 123
End Page 133
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307904
JaLCDOI 10.18926/15515
FullText URL Mem_Fac_Eng_OU_25_2_95.pdf
Author Totsuji, Hiroo| Ishikura Satoshi| Takayama Norihisa|
Abstract Critical 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.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1991-03-28
Volume volume25
Issue issue2
Start Page 95
End Page 113
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307413
JaLCDOI 10.18926/15513
FullText URL Mem_Fac_Eng_OU_25_2_81.pdf
Author Totsuji, Hiroo|
Abstract Numerical 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.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1991-03-28
Volume volume25
Issue issue2
Start Page 81
End Page 93
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307242
JaLCDOI 10.18926/15423
FullText URL Mem_Fac_Eng_OU_26_1_95.pdf
Author Kawakami, Hiroshi| Konishi, Tadataka|
Abstract This paper describes a method to construct IDEA BANK automatically. IDEA BANK is the data base of the "function-structure module" which is utilized in systematic conceptual design from Value Engineering perspectives. The method based on the Machine Learning EBL technique was evaluated and implemented for the IDEA BANK using SUN workstation. The practical implementation of the IDEA BANK acquisition was discussed after elucidating the problem and solution of the EBL technique in engineering design. In the IDEA BANK system, the structural features of an existing article are analyzed by hierarchically organized domain specific knowledge to yield a systematic explanation of how they function and attain their design goals. The explanation resulted in a generalized version of the Functional Diagram used in Value Engineering from which "function-structure module" can be extracted systematically.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1991-11-30
Volume volume26
Issue issue1
Start Page 95
End Page 108
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307756
JaLCDOI 10.18926/49322
FullText URL mfe_047_025_032.pdf
Author Nekado, Kenta| Takai, Yusuke| Nogami, Yasuyuki|
Abstract Pairing–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.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 2013-01
Volume volume47
Start Page 25
End Page 32
ISSN 1349-6115
language 英語
Copyright Holders Copyright © by the authors
File Version publisher
NAID 120005232374
JaLCDOI 10.18926/49321
FullText URL mfe_047_019_024.pdf
Author Nogami, Yasuyuki| Sumo, Taichi|
Abstract Recent 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.
Keywords pairing–friendly curve torsion point group structure rank
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 2013-01
Volume volume47
Start Page 19
End Page 24
ISSN 1349-6115
language 英語
Copyright Holders Copyright © by the authors
File Version publisher
NAID 120005232373
JaLCDOI 10.18926/49320
FullText URL mfe_047_001_018.pdf
Author Kanatani, Kenichi|
Abstract We 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.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 2013-01
Volume volume47
Start Page 1
End Page 18
ISSN 1349-6115
language 英語
Copyright Holders Copyright © by the authors
File Version publisher
NAID 120005232372
JaLCDOI 10.18926/48127
FullText URL mfe_046_021_033.pdf
Author Kanatani, Kenichi| Niitsuma, Hirotaka|
Abstract Because 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.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 2012-01
Volume volume46
Start Page 21
End Page 33
ISSN 1349-6115
language 英語
Copyright Holders Copyright © by the authors
File Version publisher
NAID 80022451622
JaLCDOI 10.18926/48126
FullText URL mfe_046_010_020.pdf
Author Kanatani, Kenichi|
Abstract We 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.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 2012-01
Volume volume46
Start Page 10
End Page 20
ISSN 1349-6115
language 英語
Copyright Holders Copyright © by the authors
File Version publisher
NAID 80022451621
JaLCDOI 10.18926/48125
FullText URL mfe_046_001_009.pdf
Author Kanatani, Kenichi| Niitsuma, Hirotaka|
Abstract We 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.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 2012-01
Volume volume46
Start Page 1
End Page 9
ISSN 1349-6115
language 英語
Copyright Holders Copyright © by the authors
File Version publisher
NAID 80022451620
JaLCDOI 10.18926/47029
FullText URL mfe_36_2_083_089.pdf
Author Watanabe, Tetsushi| Wada, Osami| Koga, Ryuji| Toyota, Yoshitaka| Miyashita, Takuya|
Abstract Suppression 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.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 2002-03
Volume volume36
Issue issue2
Start Page 83
End Page 89
ISSN 0475-0071
language 英語
File Version publisher
NAID 120003497051
JaLCDOI 10.18926/47028
FullText URL mfe_36_2_073_082.pdf
Author Hidayat, Iip Syarif| Toyota, Yoshitaka| Torigoe, Osamu| Wada, Osami| Koga, Ryuji|
Abstract A 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.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 2002-03
Volume volume36
Issue issue2
Start Page 73
End Page 82
ISSN 0475-0071
language 英語
File Version publisher
NAID 120003497050
JaLCDOI 10.18926/47027
FullText URL mfe_36_2_067_072.pdf
Author Yoshioka, Tomohiko| Tsuru, Kanji| Hayakawa, Satoshi| Osaka, Akiyoshi|
Abstract Alginic 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.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 2002-03
Volume volume36
Issue issue2
Start Page 67
End Page 72
ISSN 0475-0071
language 英語
File Version publisher
NAID 80015582225
JaLCDOI 10.18926/47026
FullText URL mfe_36_2_061_066.pdf
Author Yamagiwa, Masashi| Namba, Akitoshi| Akao, Tetsuyuki| Mizuki, Eiichi| Ohba, Michio| Sakai, Hiroshi|
Abstract The 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.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 2002-03
Volume volume36
Issue issue2
Start Page 61
End Page 66
ISSN 0475-0071
language 英語
File Version publisher
NAID 80015582224
JaLCDOI 10.18926/47025
FullText URL mfe_36_2_051_060.pdf
Author Hikida, Masaki| Magari, Masaki| Nakayama, Yasunori| Kanayama, Naoki| Ohmori, Hitoshi|
Abstract A 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.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 2002-03
Volume volume36
Issue issue2
Start Page 51
End Page 60
ISSN 0475-0071
language 英語
File Version publisher
NAID 80015582223
JaLCDOI 10.18926/47024
FullText URL mfe_36_2_043_049.pdf
Author Vaillancourt, Chico|
Abstract In 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.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 2002-03
Volume volume36
Issue issue2
Start Page 43
End Page 49
ISSN 0475-0071
language 英語
File Version publisher
NAID 120003497045
JaLCDOI 10.18926/47023
FullText URL mfe_36_2_015_042.pdf
Author Ohtani, Ryuji| Konishi, Masami| Imai, Jun| Nishi, Tatsushi|
Abstract In 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.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 2002-03
Volume volume36
Issue issue2
Start Page 15
End Page 42
ISSN 0475-0071
language 英語
File Version publisher
NAID 80015471209
JaLCDOI 10.18926/47022
FullText URL mfe_36_2_007_013.pdf
Author Abe, Takeji| Nagao, Makoto| Ohta, Tomoyuki| Nagayama, Noriyuki|
Abstract It 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.
Keywords Plasticity Deformation Inhomogeneous Material Strain Concentration Coefficient Rigid-Plastic FEM
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 2002-03
Volume volume36
Issue issue2
Start Page 7
End Page 13
ISSN 0475-0071
language 英語
File Version publisher
NAID 120003497044
JaLCDOI 10.18926/47021
FullText URL mfe_36_2_001_006.pdf
Author Sakakibara, Akira| Kanadani, Teruto| Tashiro, Tsutomu| Yoshioka, Kazumi|
Abstract The 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.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 2002-03
Volume volume36
Issue issue2
Start Page 1
End Page 6
ISSN 0475-0071
language 英語
File Version publisher
NAID 80015497758
JaLCDOI 10.18926/47005
FullText URL mfe_36_1_117_121.pdf
Author Shirosaki, Yuki| Tsuru, Kanji| Hayakawa, Satoshi| Osaka, Akiyoshi| Takashima, Seisuke|
Abstract γ-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.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 2001-12
Volume volume36
Issue issue1
Start Page 117
End Page 121
ISSN 0475-0071
language 英語
File Version publisher
NAID 120003497031