JaLCDOI 10.18926/15448
フルテキストURL Mem_Fac_Eng_OU_28_2_1.pdf
著者 竹元 嘉利| 榊原 精| 飛田 守孝|
抄録 Fine particles of Ti-Mo alloy have been prepared by means of arc method, and investigated on internal structure and phase transformation using HR-TEM and EDS. Martensite phase was observed in a particle containing comparatively low concentration of Mo, and ω phase was also found to exist in a nearly 14 % M0 particle. The structure of the ω phase in the fine particle is expanded and remarkably unstable in comparison with the bulk sample, so that it has disappeared in a few seconds during TEM observation. Moreover, the β structure of Ti-Mo particles has changed to the unusual fcc phase with irradiation of a strong electron beam.
出版物タイトル Memoirs of the Faculty of Engineering, Okayama University
発行日 1994-03-15
28巻
2号
開始ページ 1
終了ページ 7
ISSN 0475-0071
言語 English
論文のバージョン publisher
NAID 120002307644
JaLCDOI 10.18926/19634
フルテキストURL Mem_Fac_Eng_OU_32_15.pdf
著者 森 政弘| 岡 久雄|
抄録 In 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.
出版物タイトル Memoirs of the Faculty of Engineering, Okayama University
発行日 1998-04-20
32巻
1-2号
開始ページ 15
終了ページ 22
ISSN 0475-0071
言語 English
論文のバージョン publisher
NAID 120002309047
JaLCDOI 10.18926/15394
フルテキストURL Mem_Fac_Eng_OU_27_1_55.pdf
著者 東辻 浩夫| Tachibana Hiroyuki| Hashimoto Seiji| 奈良 重俊|
抄録 The ground state of a system of electrons accumulated in a pair of coupled symmetric quantum wires is analyzed on the basis of density functional theory. It is shown that, in a domain of physical parameters, electrons are localized in either of wires. The main contribution to the total energy of this system comes from the Hartree energy, or the electrostatic energy, and the exchange-correlation energy between electrons. The ground state is determined by a competition between these contributions: We have symmetric electron distributions when the Hartree energy dominates and asymmetric (localized) states are realized in the opposite case. This kind of simple system with bistable electronic states may be applied to semiconductor memory devices.
出版物タイトル Memoirs of the Faculty of Engineering, Okayama University
発行日 1992-11-25
27巻
1号
開始ページ 55
終了ページ 64
ISSN 0475-0071
言語 English
論文のバージョン publisher
NAID 120002307892
JaLCDOI 10.18926/14152
フルテキストURL Mem_Fac_Eng_39_1_52.pdf
著者 金森 克也| 東辻 千枝子| 鶴田 健二| 東辻 浩夫|
抄録 Thermal behavior of Coulomb clusters in a three dimensional confining potential is investigated by molecular dynamics simulations for system sizes of 1,000 to 20,288 ions. The specific heat of the system of shell-structured 20,000 ions is peaked almost at the same temperature as the system of bcc-structured 20,288 ions with much sharper structure for the latter. The diffusion coefficient and the peak to valley ratio of the two-dimensional pair distribution function on the outermost shell are obtained both as a function of temperature. The rotational movement of each shell in the system of 104 ions is observed.
出版物タイトル Memoirs of the Faculty of Engineering, Okayama University
発行日 2005-01
39巻
1号
開始ページ 52
終了ページ 55
ISSN 0475-0071
言語 English
論文のバージョン publisher
NAID 120002308445
JaLCDOI 10.18926/15348
フルテキストURL Mem_Fac_Eng_OU_35_21.pdf
著者 S.kovalenko, Volodymyr| Uno, Yoshiyuki| Okamoto, Yasuhiro| Anyakin, M.| Lutay, A.| Shubul, Khaled Al.|
抄録 In electric power industry, there is a problem of achieving stable joint in different components using high productive and efficient technologies. One type of these components is packages of slices for magnetic circuit of electric motors, transformers etc., which need reliable means for their fixing. Laser welding is proposed to solve this problem as an alternative for existing technologies. The development of the laser welding process is presented based on process simulation, study of heat history and comparison with experimental results. Laser beam additional scanning technique is proposed to improve the quality and efficiency of the joining operation.
出版物タイトル Memoirs of the Faculty of Engineering, Okayama University
発行日 2001-03-27
35巻
1-2号
開始ページ 21
終了ページ 28
ISSN 0475-0071
言語 English
論文のバージョン publisher
NAID 120002307424
JaLCDOI 10.18926/49322
フルテキストURL mfe_047_025_032.pdf
著者 Nekado, Kenta| Takai, Yusuke| Nogami, Yasuyuki|
抄録 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.
出版物タイトル Memoirs of the Faculty of Engineering, Okayama University
発行日 2013-01
47巻
開始ページ 25
終了ページ 32
ISSN 1349-6115
言語 English
著作権者 Copyright © by the authors
論文のバージョン publisher
NAID 120005232374
JaLCDOI 10.18926/15408
フルテキストURL Mem_Fac_Eng_OU_29_2_1.pdf
著者 榊原 精| Nakagawa, Keiyu| Kanadani, Teruto|
抄録 Effect of addition of a small amount of copper to Al- 12mass % Zn binary alloy on the process of low temperature aging is studied by hardness test and transmission electron microscopy. Age hardening rate after quenching from various temperatures is slowed down by addition of 0.5mass % copper to the binary alloy. The hardness obtained after long aging, however, is increased a little by the addition of copper. The extent of soft surface layer formed by aging in the copper-added alloy is nearly equal to that obtained in the binary alloy.
出版物タイトル Memoirs of the Faculty of Engineering, Okayama University
発行日 1995-03-27
29巻
2号
開始ページ 1
終了ページ 4
ISSN 0475-0071
言語 English
論文のバージョン publisher
NAID 120002307763
JaLCDOI 10.18926/15502
フルテキストURL Mem_Fac_Eng_OU_24_2_79.pdf
著者 佐藤 洋一郎|
抄録 In 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.
出版物タイトル Memoirs of the Faculty of Engineering, Okayama University
発行日 1990-03-29
24巻
2号
開始ページ 79
終了ページ 87
ISSN 0475-0071
言語 English
論文のバージョン publisher
NAID 120002307486
JaLCDOI 10.18926/19666
フルテキストURL Mem_Fac_Eng_OU_33_2_45.pdf
著者 Yamada Nobuya| 岡 久雄|
抄録 It 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.
出版物タイトル Memoirs of the Faculty of Engineering, Okayama University
発行日 1999-04-27
33巻
2号
開始ページ 45
終了ページ 50
ISSN 0475-0071
言語 English
論文のバージョン publisher
NAID 120002309193
JaLCDOI 10.18926/15446
フルテキストURL Mem_Fac_Eng_OU_22_1.pdf
著者 岡 久雄| 山本 辰馬|
抄録 Biomechanical impedance is relatively small compared to industrial mechanical impedance. Thus it is difficult to measure it precisely. A biomechanical impedance measuring system was developed for portable use by means of random excitation. This system doesn't require a fixed body and vibrator supporting apparatus. In order to obtain an impedance spectrum, the FFT processing is performed using a personal computer. The spectra of the biomechanical impedance which is measured on body surfaces depend on body positions and can be roughly classified into three spectra patterns : soft, stiff and intermediate. During the measurement, the measuring conditions (preload, diameter of the vibrating tip etc.) influence the results. However, it became clear that the linearity of the biomechanical impedance was satisfied in the limited measuring conditions. Accordingly it is possible to standardize the impedance and to compare it with the results under different measuring conditions.
出版物タイトル Memoirs of the Faculty of Engineering, Okayama University
発行日 1988-03-31
22巻
開始ページ 1
終了ページ 14
ISSN 0475-0071
言語 English
論文のバージョン publisher
NAID 120002307480
JaLCDOI 10.18926/15476
フルテキストURL Mem_Fac_Eng_OU_24_1_63.pdf
著者 山本 尚武| Isshiki Hiromi| 岡 久雄| 山本 辰馬|
抄録 There 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.
出版物タイトル Memoirs of the Faculty of Engineering, Okayama University
発行日 1989-11-29
24巻
1号
開始ページ 63
終了ページ 72
ISSN 0475-0071
言語 English
論文のバージョン publisher
NAID 120002307670
JaLCDOI 10.18926/15392
フルテキストURL Mem_Fac_Eng_OU_27_1_45.pdf
著者 香川 直己| 和田 修己| Hai, Xu| 古賀 隆治| Sano, Hiroya| Inubushi, Kazuyuki|
抄録 A prototype device based on the tunable diode laser absorption spectrometry was constructed and the atmospheric methane concentration near the terrain in a rice paddy field was measured. An open optical path of 50 m length was employed along with a PbSnTe diode laser. Diurnal change of methane density with 30 seconds temporal resolution was recorded associated with meteorological parameters. A feasibility was proven for a practical application for in situ study of atmospheric methane.
出版物タイトル Memoirs of the Faculty of Engineering, Okayama University
発行日 1992-11-25
27巻
1号
開始ページ 45
終了ページ 53
ISSN 0475-0071
言語 English
論文のバージョン publisher
NAID 120002307877
JaLCDOI 10.18926/15479
フルテキストURL Mem_Fac_Eng_OU_24_1_73.pdf
著者 岡 久雄| Isayama Yoshiharu| 山本 尚武| 山本 辰馬|
抄録 There 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.
出版物タイトル Memoirs of the Faculty of Engineering, Okayama University
発行日 1989-11-29
24巻
1号
開始ページ 73
終了ページ 80
ISSN 0475-0071
言語 English
論文のバージョン publisher
NAID 120002307633
JaLCDOI 10.18926/19608
フルテキストURL Mem_Fac_Eng_OU_33_1_19.pdf
著者 鷲尾 誠一| 高橋 智| 井元 智可至| 吉田 篤正|
抄録 The 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).
出版物タイトル Memoirs of the Faculty of Engineering, Okayama University
発行日 1998-11-30
33巻
1号
開始ページ 19
終了ページ 30
ISSN 0475-0071
言語 English
論文のバージョン publisher
NAID 120002309030
JaLCDOI 10.18926/15500
フルテキストURL Mem_Fac_Eng_OU_25_2_1.pdf
著者 Okada, Hiroyuki| 飛田 守孝| 榊原 精| 竹元 嘉利|
抄録 Tensile 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.
出版物タイトル Memoirs of the Faculty of Engineering, Okayama University
発行日 1991-03-28
25巻
2号
開始ページ 1
終了ページ 8
ISSN 0475-0071
言語 English
論文のバージョン publisher
NAID 120002307559
JaLCDOI 10.18926/14119
フルテキストURL Mem_Fac_Eng_OU_40_1_31.pdf
著者 小川 貴史| 東辻 千枝子| 鶴田 健二| 東辻 浩夫|
抄録 We analyze the melting of spherical Yukawa clusters by Monte Carlo simulations. Spherical clusters are expected to be found in dusty plasmas in an isotropic environment such as microgravity and serve as a model for classical clusters. We obtain the specific heat through fluctuations of the potential energy and identify its peak as the transition temperature. Melting temperatures are compared with those of bulk Yukawa systems and it is confirmed that the melting temperature increases and approaches the bulk value with the increase of the system size.
出版物タイトル Memoirs of the Faculty of Engineering, Okayama University
発行日 2006-01
40巻
1号
開始ページ 31
終了ページ 35
ISSN 0475-0071
言語 English
論文のバージョン publisher
NAID 120002308329
JaLCDOI 10.18926/15443
フルテキストURL Mem_Fac_Eng_OU_26_2_111.pdf
著者 奈良 重俊| Banzhaf Wolfgag|
抄録 An information processing task which generates combinatorial explosion and program complexity when it is treated by a serial algorithm is investigated using both Genetic Algorithms (GA) and a neural network model (NN). The task in question is to find a target memory from a set of stored entries in the form of "attractors" in a high dimensional state space. The representation of entries in the memory is distributed ("an auto associative neural network" in this paper), and the problem is to find an attractor under a given access information where the uniqueness or even existence of a solution is not always guaranteed ( an ill-posed problem ). The GA is used as an algorithm for generating a search orbit to search effectively for a state which satisfies the access condition and belongs to the target attractor basin in state space. The NN is used to retrieve the corresponding entry from the network. The results of our computer simulation indicate that the present method is superior to a search method which uses random walk in state space. Our technique may prove useful in the realization of flexible and adaptive information processing, since pattern search in high dimensional state spaces is common in various kinds of parallel information processing.
出版物タイトル Memoirs of the Faculty of Engineering, Okayama University
発行日 1992-03-28
26巻
2号
開始ページ 111
終了ページ 128
ISSN 0475-0071
言語 English
論文のバージョン publisher
NAID 120002307718
JaLCDOI 10.18926/15517
フルテキストURL Mem_Fac_Eng_OU_25_2_123.pdf
著者 Taniguchi, Takeo| Ohta, Chikashi|
抄録 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.
出版物タイトル Memoirs of the Faculty of Engineering, Okayama University
発行日 1991-03-28
25巻
2号
開始ページ 123
終了ページ 133
ISSN 0475-0071
言語 English
論文のバージョン publisher
NAID 120002307904
JaLCDOI 10.18926/14081
フルテキストURL Mem_Fac_Eng_OU_41_1_20.pdf
著者 今村 拓司| 小西 正躬| 今井 純|
抄録 In this paper, we propose a simultaneous optimization method for inventory control and production planning problem for a chemical batch plant. The plant consists of blending process, intermediate storage tanks and filling process. In the proposed method, the original problem is decomposed into production planning sub-problem and inventory control sub-problem. Then the decision variables are optimized by alternately solving each sub-problem. The solution of the proposed method is compared with that of centralized optimization method. The effectiveness of the proposed method is investigated from numerical computational results.
出版物タイトル Memoirs of the Faculty of Engineering, Okayama University
発行日 2007-01
41巻
1号
開始ページ 20
終了ページ 30
ISSN 0475-0071
言語 English
論文のバージョン publisher
NAID 120002308626
JaLCDOI 10.18926/15368
フルテキストURL Mem_Fac_Eng_OU_35_155.pdf
著者 Takahashi Hiromitsu| 宗澤 良臣| 梶原 康博| 大崎 紘一| Wada Yatarou|
抄録 This paper proposes a concept of a mobile type maintenance robot (MMR in shortly) that is controlled by the tele-operation for assuring the safety and health improvement of work forces. The main components of this system are the industrial robot, an image processing unit, vehicle and computers for tele-operation. Our focus is paid on a method that determine a pathway to move every places where troubles would occur. This method makes it possible that the MMR could arrive any place in the factory with three times of turns at most. Additionally, turning radius of the vehicle is considered for correcting the pathway near the corners to make it possible that it arrives to the place accurately.
出版物タイトル Memoirs of the Faculty of Engineering, Okayama University
発行日 2001-03-27
35巻
1-2号
開始ページ 155
終了ページ 161
ISSN 0475-0071
言語 English
論文のバージョン publisher
NAID 120002307844