検索結果 13397 件
JaLCDOI | 10.18926/15394 |
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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 |
巻 | 27巻 |
号 | 1号 |
開始ページ | 55 |
終了ページ | 64 |
ISSN | 0475-0071 |
言語 | 英語 |
論文のバージョン | publisher |
NAID | 120002307892 |
JaLCDOI | 10.18926/15393 |
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フルテキストURL | Mem_Fac_Eng_OU_30_2_15.pdf |
著者 | 岡 久雄| 藤原 史朗| |
抄録 | An estimation of muscle fatigue is very important study and many laboratory researchers had done actively in this field. The excellent measurement and analysis methods, however, have not established yet. The aim of this study was to investigate the muscle fatigue of low back, caused by sitting on the vehicle seat for a long time. The muscle viscoelasticity and the EMG (Electromyogram) were measured. The authors proposed the objective muscle fatigue index that was obtained from the result of PCA (Principal Component Analysis) by using the measured varlables. The objective muscle fatigue index suggests an adequate correlation with the subjective fatigue on the vehicle seat. |
出版物タイトル | Memoirs of the Faculty of Engineering, Okayama University |
発行日 | 1996-03-29 |
巻 | 30巻 |
号 | 2号 |
開始ページ | 15 |
終了ページ | 20 |
ISSN | 0475-0071 |
言語 | 英語 |
論文のバージョン | publisher |
NAID | 120002307965 |
JaLCDOI | 10.18926/15392 |
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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 |
巻 | 27巻 |
号 | 1号 |
開始ページ | 45 |
終了ページ | 53 |
ISSN | 0475-0071 |
言語 | 英語 |
論文のバージョン | publisher |
NAID | 120002307877 |
JaLCDOI | 10.18926/15391 |
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フルテキストURL | Mem_Fac_Eng_OU_27_1_33.pdf |
著者 | 島田 行恭| 鈴木 和彦| 佐山 隼敏| |
抄録 | Neural nets have recently become the focus of much attention, largely because of their wide range of complex and nonlinear problems. This paper presents a new integrated approach using neural networks for diagnosing process failures. The fault propagation in process is modeled by causal relationships from the fault tree and its minimal cut sets. The measurement patterns required for training and testing the neural network were obtained from fault propagation model. The network is able to diagnose even in the presence of malfunction of certain sensors. We demonstrate via a nitric acid cooler process how the neural network can learn and successfully diagnose the faults. |
出版物タイトル | Memoirs of the Faculty of Engineering, Okayama University |
発行日 | 1992-11-25 |
巻 | 27巻 |
号 | 1号 |
開始ページ | 33 |
終了ページ | 44 |
ISSN | 0475-0071 |
言語 | 英語 |
論文のバージョン | publisher |
NAID | 120002307902 |
JaLCDOI | 10.18926/15390 |
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フルテキストURL | Mem_Fac_Eng_OU_27_1_27.pdf |
著者 | Hirashima Masao| 稲葉 英男| |
抄録 | Heating and refrigerating technique such as snow melting of road and cold storage by utilizing temperature difference between underground soil and atmosphere is widely used[1-4] in a cold area. In the 1st Report, heat transfer characteristics of two phase closed thermosiphon for extracting geothermal energy is studied fundamentally. In the empirical study, heat extract rate is measured in connection with the change of atmospheric temperature utilizing real two thermosiphons on the site. Temperature distribution on the surface of the thermosiphon and underground soil around it is also measured. Based on the data of the empirical experiment, it is confirmed that prevention of freezing for fire hydrant can be achieved by geothermal heat utilizing two phase closed thermosiphon. Present paper describes the heat transfer behavior of the thermosiphon as the 2nd report. |
出版物タイトル | Memoirs of the Faculty of Engineering, Okayama University |
発行日 | 1992-11-25 |
巻 | 27巻 |
号 | 1号 |
開始ページ | 27 |
終了ページ | 32 |
ISSN | 0475-0071 |
言語 | 英語 |
論文のバージョン | publisher |
NAID | 120002307336 |
JaLCDOI | 10.18926/15389 |
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フルテキストURL | Mem_Fac_Eng_OU_30_1_121.pdf |
著者 | Kuk Hun| 谷野 哲三| 田中 雅博| |
抄録 | In this paper we provide some theoretical results on stability and sensitivity analysis in convex vector optimization. Given a family of parametrized vector optimization problems, the perturbation maps are defined as the set-valued map which associates to each parameter value the set of minimal points (properly minimal points, weakly minimal points) of the perturbed feasible set with respect to an ordering convex cone. Sufficient conditions for the upper and lower semicontinuity of the perturbations map are obtained. We also provide quantitative properties of the perturbation maps under some convexity assumptions. |
出版物タイトル | Memoirs of the Faculty of Engineering, Okayama University |
発行日 | 1995-12-28 |
巻 | 30巻 |
号 | 1号 |
開始ページ | 121 |
終了ページ | 131 |
ISSN | 0475-0071 |
言語 | 英語 |
論文のバージョン | publisher |
NAID | 120002307414 |
JaLCDOI | 10.18926/15388 |
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フルテキストURL | Mem_Fac_Eng_OU_27_1_11.pdf |
著者 | Hirashima Masao| 稲葉 英男| |
抄録 | To prevent freezing of road and aquaduct by extracting geothermal heat with two phase closed thermosiphon has been widely used in a cold area. Both heat transfer characteristics in the underground soil and function of the thermosiphon to extract geothermal heat have to be made clear for the purpose of the above system. This study is directed for the purpose to prevent freezing of fire hydrant and composed of the fundamental experiment and the empirical experiment. In the fundamental study, heat transfer behavior is studied experimentally in the small size filling bath representing the underground soil layer. After recording temperature distribution, heat transfer coefficient is measured, they are proceeded into the correlation between the dimensionless number of Nusselt, Rayleigh and Fourier. The fundamental study is described as the first report. |
出版物タイトル | Memoirs of the Faculty of Engineering, Okayama University |
発行日 | 1992-11-25 |
巻 | 27巻 |
号 | 1号 |
開始ページ | 11 |
終了ページ | 26 |
ISSN | 0475-0071 |
言語 | 英語 |
論文のバージョン | publisher |
NAID | 120002307419 |
JaLCDOI | 10.18926/15387 |
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フルテキストURL | Mem_Fac_Eng_OU_30_2_9.pdf |
著者 | 榊原 精| Kanadani, Teruto| |
抄録 | Fatigue strength of Al-Cu alloy was examined by a repeated tensile mode when the specimens were aged and reversion annealed. The specimen quenched from 723K and aged fully around room temperature showed fatigue strength which depended on the existence of soft layer, while the specimen quenched from 723K and aged in the same way showed fatigue strength independent of the existence of the soft layer. Fatigue strength of the specimen, of which the soft surface layer was removed, was the same for either quenching temperature. Fatigue strength became higher when the soft surface layer was thickened with reversion annealing for 600s at 323K after aging. The soft surface layer was thought to increase fatigue strength of the aged Al-Cu alloy as well as Al-Zn alloy. |
出版物タイトル | Memoirs of the Faculty of Engineering, Okayama University |
発行日 | 1996-03-29 |
巻 | 30巻 |
号 | 2号 |
開始ページ | 9 |
終了ページ | 13 |
ISSN | 0475-0071 |
言語 | 英語 |
論文のバージョン | publisher |
NAID | 120002307694 |
JaLCDOI | 10.18926/15386 |
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フルテキストURL | Mem_Fac_Eng_OU_30_1_111.pdf |
著者 | Ye Ju| 田中 雅博| 谷野 哲三| |
抄録 | Mutation is one of the important operators in genetic algorithm. In traditional genetic algorithm, mutation is activated stochastically. In this way it is unknown and cannot be controlled for which individuals to be mutated. Therefore, it is unavoidable that some good individuals are destroyed by mutation and then the evolutionary efficiency of the genetic algorithm is dampened. Owing to this kind of destructivity of mutation, the operator of mutation has to be limited within a very small probability, and the potentiality of mutation is consequently limited. In this paper, we present an evolutionary chain-based mutation and a control strategy of reasonable competition, in which the heuristic information provided by the evaluation function is well utilized. This method avoids the blindness of stochastic mutation. The performance improved in this method is shown by two examples, a fuzzy modeling for the identification of a nonlinear function and a typical combinatorial optimization problem-the traveling salesman problem. |
出版物タイトル | Memoirs of the Faculty of Engineering, Okayama University |
発行日 | 1995-12-28 |
巻 | 30巻 |
号 | 1号 |
開始ページ | 111 |
終了ページ | 120 |
ISSN | 0475-0071 |
言語 | 英語 |
論文のバージョン | publisher |
NAID | 120002307635 |
JaLCDOI | 10.18926/15385 |
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フルテキストURL | Mem_Fac_Eng_OU_27_1_1.pdf |
著者 | Uno, Yoshiyuki| Kubota, Shin-ichiro| Nakajima, Toshikatsu| Ogata, Kojiro| Tada, Nobuhiko| |
抄録 | Direct patterning of copper coated ceramic circuit board is experimentally investigated with Q-switched Nd:YAG laser in order to shorten the time of the trial manufacture of electronic circuit board and to adapt the flexible design change. It is pointed out that the fast direct patterning the speed of which reaches about 100 mm/s is possible if the repetition frequency and the average power are selected properly. Furthermore cutting off and/or drilling of ceramic board are also possible under the condition that the repetition frequency is less than 3kHz. This technique makes it possible the mask1ess patterning of ceramic circuit board which has been widely used recently in place of conventional glass-epoxy or phenolic resin circuit board, and it leads to the shorter time limit of delivery as compared with the conventional end-milling method. |
出版物タイトル | Memoirs of the Faculty of Engineering, Okayama University |
発行日 | 1992-11-25 |
巻 | 27巻 |
号 | 1号 |
開始ページ | 1 |
終了ページ | 10 |
ISSN | 0475-0071 |
言語 | 英語 |
論文のバージョン | publisher |
NAID | 120002307702 |
JaLCDOI | 10.18926/15384 |
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フルテキストURL | Mem_Fac_Eng_OU_30_1_99.pdf |
著者 | Wang, Ming| 和田 修己| 古賀 隆治| |
抄録 | A cylindric mirror was used, in place of a parabolic mirror, to collimate the crescent blue laser beam radiated from the Cerenkov SHG in channel waveguide configuration. The cylindric mirror radius is requested to be twice the focal length of the parabolic mirror. The focusing effect of the cylindric mirror in collimation can be compensated by slightly lifting the mirror in its normal direction. Under the condition that the mirror was declined by 5.56° and lifted by 25 μm, we got the collimated beam with divergence angle less than 1.3 mrad. In the focusing experiment, the collimated beam was focused with spotsize of 1.8 μm. The details on the analysis and experiment are reported. |
出版物タイトル | Memoirs of the Faculty of Engineering, Okayama University |
発行日 | 1995-12-28 |
巻 | 30巻 |
号 | 1号 |
開始ページ | 99 |
終了ページ | 110 |
ISSN | 0475-0071 |
言語 | 英語 |
論文のバージョン | publisher |
NAID | 120002307418 |
JaLCDOI | 10.18926/15383 |
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フルテキストURL | Mem_Fac_Eng_OU_30_1_89.pdf |
著者 | 東辻 千枝子| Sanaka Yoshiaki| 東辻 浩夫| |
抄録 | Based on the tight-binding method, electronic bands of the mixed perovskite oxides are calculated in order to develop the electronic theory of ferroelectric phase transitions in these mixtures which are difficult to describe within the phenomenological theories. Diagonal elements of Hamiltonian matrix of parent materials are assumed to differ by 0.1eV and mixtures are simulated by lattices of supercells containing 2(3) = 8 or 3(3) = 27 unit cells randomly assigned to either material. The width of the conduction and valence bands have maxima and the band gap has a minimum at intermediate mixing ratio. Results are in agreement with those of other analyses on random systems and even 2(3)-cell computation seems to serve as a first approximation for our purpose. |
出版物タイトル | Memoirs of the Faculty of Engineering, Okayama University |
発行日 | 1995-12-28 |
巻 | 30巻 |
号 | 1号 |
開始ページ | 89 |
終了ページ | 97 |
ISSN | 0475-0071 |
言語 | 英語 |
論文のバージョン | publisher |
NAID | 120002307957 |
JaLCDOI | 10.18926/15382 |
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フルテキストURL | Mem_Fac_Eng_OU_35_207.pdf |
著者 | 中西 透| Fujiwara Toru| |
抄録 | In the group signature scheme with a trusted party, a verifier can determine whether or not a signature is made by a member of the group, but cannot identify the member who signed the signature. In case of dispute later on, the signer can be identified by the trusted party. However, for efficient group signature schemes proposed so far, removing a member from the group can be not efficiently performed. In this paper, a group signature scheme with an easy membership canceling is proposed. By sending a request to use a resource together with the group signature on it to the manager of the resource, the manager can control anonymous accesses to the resource. In such an application, the proposed group signature scheme is suitable for canceling of the access privilege. |
出版物タイトル | Memoirs of the Faculty of Engineering, Okayama University |
発行日 | 2001-03-27 |
巻 | 35巻 |
号 | 1-2号 |
開始ページ | 207 |
終了ページ | 212 |
ISSN | 0475-0071 |
言語 | 英語 |
論文のバージョン | publisher |
NAID | 120002307232 |
JaLCDOI | 10.18926/15381 |
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フルテキストURL | Mem_Fac_Eng_OU_30_1_75.pdf |
著者 | 東辻 浩夫| 井上 嘉彦| 岸本 篤也| 東辻 千枝子| 奈良 重俊| |
抄録 | Molecular dynamics of the Yukawa system, the system of particles interacting via the Yukawa or the screened Coulomb potential, are formulated for various statistical ensembles and external conditions. The Yukawa potential smoothly interpolates the long-range Coulomb and the short-range interactions by adjusting a single parameter, the screening length. In order to reduce the effect of boundaries, the periodic boundary conditions are imposed and the deformations of the fundamental vectors of periodicity are taken into account. Ewald-type expressions for interaction energy, force, and kinematic pressure are given explicitly. |
出版物タイトル | Memoirs of the Faculty of Engineering, Okayama University |
発行日 | 1995-12-28 |
巻 | 30巻 |
号 | 1号 |
開始ページ | 75 |
終了ページ | 87 |
ISSN | 0475-0071 |
言語 | 英語 |
論文のバージョン | publisher |
NAID | 120002307479 |
JaLCDOI | 10.18926/15380 |
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フルテキストURL | Mem_Fac_Eng_OU_35_197.pdf |
著者 | Nogami, Yasuyuki| Morikawa, Yoshitaka| |
抄録 | Modern communication engineerings, such as elliptic curve cryptographies, often requires algebra on finite extension field defined by modulus arithmetic with an irreducible polynomial. This paper provides a new method to detemine the minimal (irreducible) polynomial of a given proper element in finite extension field. In the conventional determination method, as we have to solve the simultaneous equations, the computation is very involved. In this paper, the well known "trace" is extended to higher degree traces. Using the new traces, we yield the coefficient formula of the desired minimal polynomial. The new method becomes very simple without solving the simultaneous equations, and about twice faster than the conventional method in computation speed. |
キーワード | finite field minimal polynomial irreducible polynomial higher degree trace trace cryptography |
出版物タイトル | Memoirs of the Faculty of Engineering, Okayama University |
発行日 | 2001-03-27 |
巻 | 35巻 |
号 | 1-2号 |
開始ページ | 197 |
終了ページ | 205 |
ISSN | 0475-0071 |
言語 | 英語 |
論文のバージョン | publisher |
NAID | 120002307992 |
JaLCDOI | 10.18926/15379 |
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フルテキストURL | Mem_Fac_Eng_OU_30_1_63.pdf |
著者 | Koshimoto Marcos| Mahmood Zaheed| 加川 幸雄| |
抄録 | Optical fibers or integrated optical waveguides have arbitrary cross-sectional index or refraction distribution. An efficient finite element method for analyzing the propagation characteristics of dielectric / optical waveguides with open boundary is presented. The propagation modes are hybrid, for which a variational expression is formulated in terms of the longitudinal electric and magnetic field components. Infinite elements are introduced to consider open boundary or to extend the region to infinity. Several specific examples are given and the results are compared with those obtained by other approximate methods. Very close agreements have been found. |
出版物タイトル | Memoirs of the Faculty of Engineering, Okayama University |
発行日 | 1995-12-28 |
巻 | 30巻 |
号 | 1号 |
開始ページ | 63 |
終了ページ | 73 |
ISSN | 0475-0071 |
言語 | 英語 |
論文のバージョン | publisher |
NAID | 120002307545 |
JaLCDOI | 10.18926/15378 |
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フルテキストURL | Mem_Fac_Eng_OU_35_191.pdf |
著者 | Yoshida Takanobu| 宗澤 良臣| 大崎 紘一| 梶原 康博| Ohta Kazuharu| |
抄録 | We developed the disassembly system that uses the impulsive load and disassembly tools to disassemble used appliances economically. The main components of this system are impulse hammer, a lift table and developed disassembly tools. Several types of disassembly tools are developed to punch out fastened portion on a part and cut off the shaft of screw or connection pin of IC-chip. A simulation model is proposed to explain and formulate how the fastening point of product is broken and cut. Three kinds of disassembly tools are designed. The actual disassembly system is developed by using proposed simulation models and disassembly tools. |
出版物タイトル | Memoirs of the Faculty of Engineering, Okayama University |
発行日 | 2001-03-27 |
巻 | 35巻 |
号 | 1-2号 |
開始ページ | 191 |
終了ページ | 196 |
ISSN | 0475-0071 |
言語 | 英語 |
論文のバージョン | publisher |
NAID | 120002307328 |
JaLCDOI | 10.18926/15377 |
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フルテキストURL | Mem_Fac_Eng_OU_30_1_47.pdf |
著者 | 加川 幸雄| Sun Yonghao| Mahmood Zaheed| |
抄録 | Regular boundary element method is employed for the variational formulation of Helmholtz equation that governs the waveguiding problems. Like in the Charge simulation method, in this method, the source points associated with the fundamental solutions are allocated outside the domain so that the singular integrals which occur in the standard boundary element procedure can be avoided. First, the formulation is developed for the two-dimensional scalar Helmholtz problem solving for the axial components of either electric or magnetic fields. The application of the formulation is shown for simple hollow rectangular waveguide and dielectric-slab-loaded rectangular waveguide. Then the formulation is extended for the analysis of dielectric waveguides of open type incorporating axial components of both electric and magnetic fields, for the solution of the propagating modes which are generally of hybrid types. To show the validity and quality of the formulation, it is applied to a circular step-index optical waveguide and a dielectric rectangular waveguide. Very close agreements have been found when the solutions are compared with the ones obtained by different methods. One distinct merit of the extended formulation is that it has been fixed to suppress the spurious solutions which are encountered while solved by the conventional boundary element method. |
出版物タイトル | Memoirs of the Faculty of Engineering, Okayama University |
発行日 | 1995-12-28 |
巻 | 30巻 |
号 | 1号 |
開始ページ | 47 |
終了ページ | 62 |
ISSN | 0475-0071 |
言語 | 英語 |
論文のバージョン | publisher |
NAID | 120002307187 |
JaLCDOI | 10.18926/15376 |
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フルテキストURL | Mem_Fac_Eng_OU_35_183.pdf |
著者 | Tabuchi Satoshi| 大崎 紘一| 梶原 康博| 宗澤 良臣| |
抄録 | This research proposes a strategy for reducing both electricity charge and environmental load by considering multi energy sources. The reduction of the contract electric demand is considered, and its differential cost is used for purchasing substitute power sources. Some variables, such as the amount of reduced contract demand, and amount of electricity are generated by each substitute power source. By using those variables, we formulate a simulation model that enables to minimize the energy cost and environmental cost. |
出版物タイトル | Memoirs of the Faculty of Engineering, Okayama University |
発行日 | 2001-03-27 |
巻 | 35巻 |
号 | 1-2号 |
開始ページ | 183 |
終了ページ | 189 |
ISSN | 0475-0071 |
言語 | 英語 |
論文のバージョン | publisher |
NAID | 120002307173 |
JaLCDOI | 10.18926/15375 |
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フルテキストURL | Mem_Fac_Eng_OU_35_177.pdf |
著者 | Kanki Kunihiko| 大崎 紘一| 梶原 康博| 宗澤 良臣| Ohta Kazuharu| |
抄録 | The focus of this paper is on the analysis of delivery motion of human, development of an image processing method based on the motion analysis and development of the cooperative delivery robot using the image processing method. The proposed image processing method uses two cameras, and it uses a stereo reconstruction technique for measuring position and postures of hands. In addition, this image processing method recognize the number of fingers extending consciously, so the cooperative human beings could choose the kind of tool which he wants by holding out his hand in front of cameras. |
出版物タイトル | Memoirs of the Faculty of Engineering, Okayama University |
発行日 | 2001-03-27 |
巻 | 35巻 |
号 | 1-2号 |
開始ページ | 177 |
終了ページ | 182 |
ISSN | 0475-0071 |
言語 | 英語 |
論文のバージョン | publisher |
NAID | 120002307899 |