著者 東辻 浩夫| Ishikura Satoshi| Takayama Norihisa|
発行日 1991-03-28
出版物タイトル Memoirs of the Faculty of Engineering, Okayama University
25巻
2号
資料タイプ 紀要論文
著者 東辻 浩夫|
発行日 1991-03-28
出版物タイトル Memoirs of the Faculty of Engineering, Okayama University
25巻
2号
資料タイプ 紀要論文
JaLCDOI 10.18926/15512
フルテキストURL Mem_Fac_Eng_OU_25_2_69.pdf
著者 Tsuchiya Takao| 加川 幸雄|
抄録 A 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.
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 69
終了ページ 80
ISSN 0475-0071
言語 English
論文のバージョン publisher
NAID 120002307747
JaLCDOI 10.18926/15511
フルテキストURL Mem_Fac_Eng_OU_25_2_55.pdf
著者 Ohkura Akira| 亀山 嘉正| 佐山 隼敏| 鈴木 和彦| Fukumoto Shuichi|
抄録 AHP 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.
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 55
終了ページ 67
ISSN 0475-0071
言語 English
論文のバージョン publisher
NAID 120002307741
JaLCDOI 10.18926/15510
フルテキストURL Mem_Fac_Eng_OU_25_2_39.pdf
著者 Nsunge Felix Chintu| 冨田 栄二| 浜本 嘉輔|
抄録 Velocity 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.
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 39
終了ページ 54
ISSN 0475-0071
言語 English
論文のバージョン publisher
NAID 120002307456
JaLCDOI 10.18926/15508
フルテキストURL Mem_Fac_Eng_OU_25_2_25.pdf
著者 Nsunge Felix Chintu| 冨田 栄二| 浜本 嘉輔|
抄録 A 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).
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 25
終了ページ 38
ISSN 0475-0071
言語 English
論文のバージョン publisher
NAID 120002307676
JaLCDOI 10.18926/15507
フルテキストURL Mem_Fac_Eng_OU_24_2_99.pdf
著者 谷口 健男| Fujiwara Kohji|
抄録 This 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.
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 99
終了ページ 112
ISSN 0475-0071
言語 English
論文のバージョン publisher
NAID 120002307515
JaLCDOI 10.18926/15506
フルテキストURL Mem_Fac_Eng_OU_25_2_17.pdf
著者 榊原 精| Kanadani, Teruto| Kaneeda, Toshiaki| Hosokawa, Norio|
抄録 Effect 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.
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 17
終了ページ 23
ISSN 0475-0071
言語 English
論文のバージョン publisher
NAID 120002307685
JaLCDOI 10.18926/15505
フルテキストURL Mem_Fac_Eng_OU_24_2_89.pdf
著者 横平 徳美|
抄録 This 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.
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 89
終了ページ 98
ISSN 0475-0071
言語 English
論文のバージョン publisher
NAID 120002307212
JaLCDOI 10.18926/15503
フルテキストURL Mem_Fac_Eng_OU_25_2_9.pdf
著者 Mikuni, Masato| 飛田 守孝| Nishida, Norihide| 榊原 精| 山田 益男|
抄録 Strains 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.
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 9
終了ページ 15
ISSN 0475-0071
言語 English
論文のバージョン publisher
NAID 120002307429
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 10.18926/15501
フルテキストURL Mem_Fac_Eng_OU_24_2_67.pdf
著者 名合 宏之| 前野 詩朗|
抄録 Many 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.
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 67
終了ページ 78
ISSN 0475-0071
言語 English
論文のバージョン publisher
NAID 120002307928
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 10.18926/15499
フルテキストURL Mem_Fac_Eng_OU_24_2_49.pdf
著者 森 忠次| Machida Ken-ichi|
抄録 Distance 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.
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 49
終了ページ 65
ISSN 0475-0071
言語 English
論文のバージョン publisher
NAID 120002307544
JaLCDOI 10.18926/15498
フルテキストURL Mem_Fac_Eng_OU_25_1_99.pdf
著者 西垣 誠| 竹下 祐二| 河野 伊一郎|
抄録 In 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.
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 99
終了ページ 109
ISSN 0475-0071
言語 English
論文のバージョン publisher
NAID 120002307452
JaLCDOI 10.18926/15497
フルテキストURL Mem_Fac_Eng_OU_24_2_41.pdf
著者 東辻 浩夫|
抄録 A 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.
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 41
終了ページ 47
ISSN 0475-0071
言語 English
論文のバージョン publisher
NAID 120002307289
JaLCDOI 10.18926/15496
フルテキストURL Mem_Fac_Eng_OU_25_1_89.pdf
著者 阿部 宏史| Oishi Manabu|
抄録 Multidimensional 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.
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 89
終了ページ 98
ISSN 0475-0071
言語 English
論文のバージョン publisher
NAID 120002307404
JaLCDOI 10.18926/15495
フルテキストURL Mem_Fac_Eng_OU_24_2_31.pdf
著者 岡 久雄| Isayama Yoshiharu| Nakauchi Makoto| 山本 辰馬|
抄録 A 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.
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 31
終了ページ 40
ISSN 0475-0071
言語 English
論文のバージョン publisher
NAID 120002307725
JaLCDOI 10.18926/15494
フルテキストURL Mem_Fac_Eng_OU_25_1_71.pdf
著者 Myojin Sho| Yamada Masahito| Fujii Naoto|
抄録 A 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.
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 71
終了ページ 87
ISSN 0475-0071
言語 English
論文のバージョン publisher
NAID 120002307618
JaLCDOI 10.18926/15493
フルテキストURL Mem_Fac_Eng_OU_24_2_17.pdf
著者 小西 忠孝| 馬場 充|
抄録 Pressure 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.
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 17
終了ページ 30
ISSN 0475-0071
言語 English
論文のバージョン publisher
NAID 120002307431