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 10.18926/15395
フルテキストURL Mem_Fac_Eng_OU_27_1_65.pdf
著者 奈良 重俊| Hara Yuji| 東辻 浩夫|
抄録 Quantum mechnical electron wave transfer between two quantum wires which are weakly coupled via a thin potential barrier is considered. The total electronic states are calculated with both analytical ( no field case ) and numerical methods ( under applied electric fields ). The transfer efficiency is evaluated for several specified cases of geometrical structures, potential barrier heights and the externally applied electric field. Estimated trasfer time is of the order of one picosecond in typical mesoscopic structures. The model in this paper can be used to determine important structure parameters for experiments on electron directional coupler controled by external elctric field.
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 65
終了ページ 79
ISSN 0475-0071
言語 English
論文のバージョン publisher
NAID 120002307405
JaLCDOI 10.18926/15403
フルテキストURL Mem_Fac_Eng_OU_27_2_19.pdf
著者 奈良 重俊| 東辻 浩夫|
抄録 Numerical simulations of a single layer recurrent neural network model in which the synaptic connection matrix is formed by summing cyclic products of succesive patterns show that complex dynamics can occur with the reduction of a connectivity parameter which is the number of connection between neurons. The structure in these dynamics is discussed from the viewpoint of realizing complex function using complex dynamics.
出版物タイトル Memoirs of the Faculty of Engineering, Okayama University
発行日 1993-03-25
27巻
2号
開始ページ 19
終了ページ 40
ISSN 0475-0071
言語 English
論文のバージョン publisher
NAID 120002307451
JaLCDOI 10.18926/15418
フルテキストURL Mem_Fac_Eng_OU_26_1_51.pdf
著者 東辻 浩夫| Shirokoshi Hideki| 奈良 重俊|
抄録 Variable shape molecular dynamics is formulated for the one-component plasma and the structural transition from the fcc lattice to the bcc lattice has been observed. It is emphasized that the condition of constant volume should be imposed when deformations of periodic boundary conditions are taken into account.
出版物タイトル Memoirs of the Faculty of Engineering, Okayama University
発行日 1991-11-30
26巻
1号
開始ページ 51
終了ページ 59
ISSN 0475-0071
言語 English
論文のバージョン publisher
NAID 120002307555
JaLCDOI 10.18926/15432
フルテキストURL Mem_Fac_Eng_OU_28_1_1.pdf
著者 奈良 重俊| Miho Shigeru| 東辻 浩夫|
抄録 The structural stabilities of bulk Si, Ge, and GaAs are discussed based on the total energy evaluated by the summation of the band structure energy and the short-range repulsive potential between ions. The band structure energy is calculated by means of the simple tight-binding method. The tight-binding parameters are determined so as to fit to the results of a pseude potential calculation and Harrison's model is employed to include the influence of lattice deformation. The short-range-force is assumed to be of the exponential form and parameters are determined so as to reproduce an experimental value of bulk modulus. This treatment qualitatively well describes structural properties in spite of the simple computational procedure and roughly gives the known variation of the total energy for a <100> uniaxial strain. This method is able to be applied to an investigation of the structural stabilities of superlattices, for example, a strained layer superlattice consisting of hetero-semiconductors.
出版物タイトル Memoirs of the Faculty of Engineering, Okayama University
発行日 1993-11-30
28巻
1号
開始ページ 1
終了ページ 25
ISSN 0475-0071
言語 English
論文のバージョン publisher
NAID 120002307238
JaLCDOI 10.18926/15434
フルテキストURL Mem_Fac_Eng_OU_28_1_27.pdf
著者 東辻 浩夫| Tachibana Hiroyuki| Fujimura Hidenori| 奈良 重俊|
抄録 The ground states of interacting electrons in coupled quantum wires are analyzed on the basis of the density functional theory. The exchange-correlation potential is calculated from 'exact' results given by the Green's function Monte Carlo method in two and three dimensions. It is shown that the critical density signifying the change from symmetrical to asymmetrical ground state is weakly dependent on the details of the exchange-correlation potential. These critical values are compared with the result of the three-dimensional analysis for a single wire.
出版物タイトル Memoirs of the Faculty of Engineering, Okayama University
発行日 1993-11-30
28巻
1号
開始ページ 27
終了ページ 38
ISSN 0475-0071
言語 English
論文のバージョン publisher
NAID 120002307565
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 10.18926/15460
フルテキストURL Mem_Fac_Eng_OU_28_2_45.pdf
著者 東辻 浩夫| 橋本 成仁| 奈良 重俊|
抄録 Difficulties 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.
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 45
終了ページ 52
ISSN 0475-0071
言語 English
論文のバージョン publisher
NAID 120002307158
JaLCDOI 10.18926/20011
フルテキストURL Mem_Fac_Eng_OU_29_1_7.pdf
著者 Hiroyuki Tachibana| 東辻 浩夫| 奈良 重俊| 東辻 千枝子|
抄録 Effects 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.
出版物タイトル Memoirs of the Faculty of Engineering, Okayama University
発行日 1994-11-30
29巻
1号
開始ページ 7
終了ページ 14
ISSN 0475-0071
言語 English
論文のバージョン publisher
NAID 120002310741
JaLCDOI 10.18926/15369
フルテキストURL Mem_Fac_Eng_OU_30_1_19.pdf
著者 中村 隆夫| 山本 尚武|
抄録 This paper describes a new measurement method and principle of detection of biodynamics using bioelectrical impedance method based on four-electrode technique with sinusoidal constant current. This method uses a human body itself as a part of the sensor. First, we show a bioelectrical impedance measuring device and the change of bioelectrical resistance is measured in human movement. Second, we proposes a principle of detection of biodynamics based on correspondence of magnitude, form and stability of movement to impedance waveform. Hence we can use this method for the judgement of sports skill using the impedance characteristics.
出版物タイトル Memoirs of the Faculty of Engineering, Okayama University
発行日 1995-12-28
30巻
1号
開始ページ 19
終了ページ 24
ISSN 0475-0071
言語 English
論文のバージョン publisher
NAID 120002307151
JaLCDOI 10.18926/15480
フルテキストURL Mem_Fac_Eng_OU_25_1_1.pdf
著者 Gao Hong| 和田 力| 則次 俊郎|
抄録 How 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.
出版物タイトル Memoirs of the Faculty of Engineering, Okayama University
発行日 1990-12-14
25巻
1号
開始ページ 1
終了ページ 13
ISSN 0475-0071
言語 English
論文のバージョン publisher
NAID 120002308010
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 10.18926/15436
フルテキストURL Mem_Fac_Eng_OU_26_2_69.pdf
著者 Fujii, Tatsuo| Sakata Naoki| Nanba, Tokuro| Osaka, Akiyoshi| Miura, Yoshinari| Takada, Jun|
抄録 (001)-oriented Ti(2)O(3) films were epitaxially grown on a(001)-face of sapphire single-crystalline substrate by an activated reactive evaporation method. The formation ranges of stoichiometric and nonstoichiometric Ti(2)O(3) films were determined as a function of the substrate temperature (Ts), the oxygen pressure (Po(2)) and the deposition rate. Stoichiometric Ti(2)O(3) films were grown at Ts≧673K under Po(2)≧1.0×10(-4)Torr, which showed the metal-insulator transition with a sharp change in electrical resistivity from 3.5×10(-2) to 2.6×10(-3)Ωcm at 361K. Nonstoichiometric films prepared under less oxidized conditions did not exhibit the transition. The nonstoichiometry of the Ti(2)O(3)films was discussed in terms of excess Ti ions.
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 69
終了ページ 75
ISSN 0475-0071
言語 English
論文のバージョン publisher
NAID 120002307639
JaLCDOI 10.18926/14053
フルテキストURL Mem_Fac_Eng_OU_42_1.pdf
著者 Asatani Jun| 甲本 卓也| Toru Fujiwara| Tadao Kasami|
抄録 Two typical examples, the (32, 21, 6) and (64, 45, 8) extended code of primitive permuted BCH codes, are considered. The sets of minimum weight codewords are analyzed in terms of Boolean polynomial representation. They are classied by using their split weight structure with respect to the left and right half trellis sections, and for each class, the standard form is presented. Based on the results, we can generate a proper list of the minimum weight codewords of the codes.
キーワード Boolean polynomial representation extended BCH codes minimum weight codewords binary shift invariance property
出版物タイトル Memoirs of the Faculty of Engineering, Okayama University
発行日 2008-01
42巻
1号
開始ページ 1
終了ページ 9
ISSN 0475-0071
言語 English
論文のバージョン publisher
NAID 120002308333
JaLCDOI 10.18926/14055
フルテキストURL Mem_Fac_Eng_OU_42_10.pdf
著者 金谷 健一|
抄録 The author introduced the "geometric AIC" and the "geometric MDL" as model selection criteria for geometric fitting problems. These correspond to Akaike’s "AIC" and Rissanen's "BIC", respectively, well known in the statistical estimation framework. Another criterion well known is Schwarz’ "BIC", but its counterpart for geometric fitting has been unknown. This paper introduces the corresponding criterion, which we call the "geometric BIC", and shows that it is of the same form as the geometric MDL. We present the underlying logical reasoning of Bayesian estimation.
出版物タイトル Memoirs of the Faculty of Engineering, Okayama University
発行日 2008-01
42巻
1号
開始ページ 10
終了ページ 17
ISSN 0475-0071
言語 English
論文のバージョン publisher
NAID 120002308447
JaLCDOI 10.18926/14056
フルテキストURL Mem_Fac_Eng_OU_42_18.pdf
著者 金谷 健一| Yasuyuki Sugaya|
抄録 We classify and review existing algorithms for computing the fundamental matrix from point correspondences and propose new effective schemes: 7-parameter Levenberg-Marquardt (LM) search, EFNS, and EFNS-based bundle adjustment. Doing experimental comparison, we show that EFNS and the 7-parameter LM search exhibit the best performance and that additional bundle adjustment does not increase the accuracy to any noticeable degree.
出版物タイトル Memoirs of the Faculty of Engineering, Okayama University
発行日 2008-01
42巻
1号
開始ページ 18
終了ページ 35
ISSN 0475-0071
言語 English
論文のバージョン publisher
NAID 120002308468
JaLCDOI 10.18926/14060
フルテキストURL Mem_Fac_Eng_OU_42_53.pdf
著者 Chai Hong| 東辻 浩夫|
抄録 In order to transfer quantum information, the use of spin chains has been proposed and their transfer characteristics have been analyzed. As one of the latter, the maximum of the transfer probability over sufficiently long time period is often considered important and some examples with high maximum values have been given. In these examples, the coupling between neighboring spins are tuned so as to attain high efficiency. In this article, we discuss the effect of noise on the values of coupling constant. As a result, we propose a system where the efficiency is high and also the effect of noise is small.
出版物タイトル Memoirs of the Faculty of Engineering, Okayama University
発行日 2008-01
42巻
1号
開始ページ 53
終了ページ 55
ISSN 0475-0071
言語 English
論文のバージョン publisher
NAID 120002308635
JaLCDOI 10.18926/14086
フルテキストURL Mem_Fac_Eng_OU_41_1_63.pdf
著者 金谷 健一| 菅谷 保之|
抄録 The convergence performance of typical numerical schemes for geometric fitting for computer vision applications is compared. First, the problem and the associated KCR lower bound are stated. Then, three well known fitting algorithms are described: FNS, HEIV, and renormalization. To these, we add a special variant of Gauss-Newton iterations. For initialization of iterations, random choice, least squares, and Taubin’s method are tested. Numerical simulations and real image experiments and conducted for fundamental matrix computation and ellipse fitting, which reveals different characteristics of each method.
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 63
終了ページ 72
ISSN 0475-0071
言語 English
論文のバージョン publisher
NAID 120002308585
JaLCDOI 10.18926/14087
フルテキストURL Mem_Fac_Eng_OU_41_1_73.pdf
著者 金谷 健一|
抄録 A rigorous accuracy analysis is given to various techniques for estimating parameters of geometric models from noisy data for computer vision applications. First, it is pointed out that parameter estimation for vision applications is very different in nature from traditional statistical analysis and hence a different mathematical framework is necessary in such a domain. After general theories on estimation and accuracy are given, typical existing techniques are selected, and their accuracy is evaluated up to higher order terms. This leads to a “hyperaccurate” method that outperforms existing methods.
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 73
終了ページ 92
ISSN 0475-0071
言語 English
論文のバージョン publisher
NAID 120002308410
JaLCDOI 10.18926/15381
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
30巻
1号
開始ページ 75
終了ページ 87
ISSN 0475-0071
言語 English
論文のバージョン publisher
NAID 120002307479