検索結果 989 件
| JaLCDOI | 10.18926/15538 |
|---|---|
| フルテキストURL | Mem_Sch_Eng_OU_1_13.pdf |
| 著者 | Kashiwada Yukio| Akiyama Koichi| |
| 抄録 | In order to make clear how the efflux angle changes in a small crankcase scavenged engine cylinder and in a large loop scavenged engine cylinder, the inlet flow pattern in the single cycle model cylinder has been observed by a high speed motion camera. In general, the scavenging air stream is not effluent in the designed direction of the scavenging port at comparatively slight opening, and the efflux angle changes in proportion to port opening advance. In a small crankcase scavenged engine cylinder, to keep the scavenging air stream in the direction of the scavenging port it is effective to incline the scavenging air passage between the crankcase and the cylinder, and to make thicker the cylinder wall where located scavenging port. In a large loop scavenged engine cylinder to coincide the scavenging air stream with the direction of the scavenging port in the early stage of the scavenging, it has an effect to set the guide plate the position of 1/2 at port height. |
| 出版物タイトル | Memoirs of the School of Engineering, Okayama University |
| 発行日 | 1966-03-31 |
| 巻 | 1巻 |
| 号 | 1号 |
| 開始ページ | 13 |
| 終了ページ | 22 |
| ISSN | 0475-0071 |
| 言語 | 英語 |
| 論文のバージョン | publisher |
| NAID | 120002307846 |
| JaLCDOI | 10.18926/15537 |
|---|---|
| フルテキストURL | Mem_Sch_Eng_OU_1_1.pdf |
| 著者 | Honda Kazuo| Konaga Tetsuro| |
| 抄録 | In the field of mechanical engineering, the need for a simple but effective way of evaluating the fatigue strength and lifetime of structural materials is an important problem with which the design engineers have faced. Accordingly, a cunsiderable amount of investigations have been made in this field. However, the basic nature of fatigue damage and the conditions which lead to the initiation and propagation of fatigue cracks are not sufficiently understood. Nor any satisfactory method of assessing the exact state of fatigue damage has yet been found. X-ray diffraction technique is not a new as the method of experimental study, but has often been adopted for direct and non-destructive observations of change in the local structures of crystalline materials at fundamental research. X-ray technique is one of the most powerful means to investigate the changes of microscopic- structure due to external forces, considering the fatigue phenomena occur on the surface of materials. Accordingly, one of the authors have studied the relations of half-value breadth of X-ray diffraction lines, residual stresses and hardness and number of cycles of fatigue stresses in detail for various sorts of engineering metallic materials. In the results of a number of experiments, it has been found that the variation in half-value breadth showed very regular relation with number of stress cycles, the authors have reported that the lifetime of materials in fatigue could be predicted. Consequently, it needs to investigate whether or not this predicting method is fitted for alloy containg α and β phase, moreover, it is interesting to make clear the fatigue mechanism of such materials which are present two phases having the different yield stress and type of crystal structure. |
| 出版物タイトル | Memoirs of the School of Engineering, Okayama University |
| 発行日 | 1966-03-31 |
| 巻 | 1巻 |
| 号 | 1号 |
| 開始ページ | 1 |
| 終了ページ | 12 |
| ISSN | 0475-0071 |
| 言語 | 英語 |
| 論文のバージョン | publisher |
| NAID | 120002307488 |
| 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 |
| 巻 | 25巻 |
| 号 | 2号 |
| 開始ページ | 123 |
| 終了ページ | 133 |
| ISSN | 0475-0071 |
| 言語 | 英語 |
| 論文のバージョン | publisher |
| NAID | 120002307904 |
| JaLCDOI | 10.18926/15516 |
|---|---|
| フルテキストURL | Mem_Fac_Eng_OU_25_2_115.pdf |
| 著者 | 谷口 健男| Irie Hirotsugu| |
| 抄録 | Nested dissection method is an elimination method for a set of linear algebraic equations with minimum fillins. Physically it divides a domain into four subdomains, and each subdomain is again divided into four. This procedure is repeated till all nodes are included in some subdomains. Using this characteristic, the authors examine the efficiency of the method on the transputer. |
| 出版物タイトル | Memoirs of the Faculty of Engineering, Okayama University |
| 発行日 | 1991-03-28 |
| 巻 | 25巻 |
| 号 | 2号 |
| 開始ページ | 115 |
| 終了ページ | 122 |
| ISSN | 0475-0071 |
| 言語 | 英語 |
| 論文のバージョン | publisher |
| NAID | 120002307316 |
| JaLCDOI | 10.18926/15515 |
|---|---|
| フルテキストURL | Mem_Fac_Eng_OU_25_2_95.pdf |
| 著者 | Totsuji, Hiroo| Ishikura Satoshi| Takayama Norihisa| |
| 抄録 | 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. |
| 出版物タイトル | Memoirs of the Faculty of Engineering, Okayama University |
| 発行日 | 1991-03-28 |
| 巻 | 25巻 |
| 号 | 2号 |
| 開始ページ | 95 |
| 終了ページ | 113 |
| ISSN | 0475-0071 |
| 言語 | 英語 |
| 論文のバージョン | publisher |
| NAID | 120002307413 |
| JaLCDOI | 10.18926/15513 |
|---|---|
| フルテキストURL | Mem_Fac_Eng_OU_25_2_81.pdf |
| 著者 | Totsuji, Hiroo| |
| 抄録 | 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. |
| 出版物タイトル | Memoirs of the Faculty of Engineering, Okayama University |
| 発行日 | 1991-03-28 |
| 巻 | 25巻 |
| 号 | 2号 |
| 開始ページ | 81 |
| 終了ページ | 93 |
| ISSN | 0475-0071 |
| 言語 | 英語 |
| 論文のバージョン | publisher |
| NAID | 120002307242 |
| 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 |
| 巻 | 25巻 |
| 号 | 2号 |
| 開始ページ | 69 |
| 終了ページ | 80 |
| ISSN | 0475-0071 |
| 言語 | 英語 |
| 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 |
| 巻 | 25巻 |
| 号 | 2号 |
| 開始ページ | 55 |
| 終了ページ | 67 |
| ISSN | 0475-0071 |
| 言語 | 英語 |
| 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 |
| 巻 | 25巻 |
| 号 | 2号 |
| 開始ページ | 39 |
| 終了ページ | 54 |
| ISSN | 0475-0071 |
| 言語 | 英語 |
| 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 |
| 巻 | 25巻 |
| 号 | 2号 |
| 開始ページ | 25 |
| 終了ページ | 38 |
| ISSN | 0475-0071 |
| 言語 | 英語 |
| 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 |
| 巻 | 24巻 |
| 号 | 2号 |
| 開始ページ | 99 |
| 終了ページ | 112 |
| ISSN | 0475-0071 |
| 言語 | 英語 |
| 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 |
| 巻 | 25巻 |
| 号 | 2号 |
| 開始ページ | 17 |
| 終了ページ | 23 |
| ISSN | 0475-0071 |
| 言語 | 英語 |
| 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 |
| 巻 | 24巻 |
| 号 | 2号 |
| 開始ページ | 89 |
| 終了ページ | 98 |
| ISSN | 0475-0071 |
| 言語 | 英語 |
| 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 |
| 巻 | 25巻 |
| 号 | 2号 |
| 開始ページ | 9 |
| 終了ページ | 15 |
| ISSN | 0475-0071 |
| 言語 | 英語 |
| 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 |
| 巻 | 24巻 |
| 号 | 2号 |
| 開始ページ | 79 |
| 終了ページ | 87 |
| ISSN | 0475-0071 |
| 言語 | 英語 |
| 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 |
| 巻 | 24巻 |
| 号 | 2号 |
| 開始ページ | 67 |
| 終了ページ | 78 |
| ISSN | 0475-0071 |
| 言語 | 英語 |
| 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 |
| 巻 | 25巻 |
| 号 | 2号 |
| 開始ページ | 1 |
| 終了ページ | 8 |
| ISSN | 0475-0071 |
| 言語 | 英語 |
| 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 |
| 巻 | 24巻 |
| 号 | 2号 |
| 開始ページ | 49 |
| 終了ページ | 65 |
| ISSN | 0475-0071 |
| 言語 | 英語 |
| 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 |
| 巻 | 25巻 |
| 号 | 1号 |
| 開始ページ | 99 |
| 終了ページ | 109 |
| ISSN | 0475-0071 |
| 言語 | 英語 |
| 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 |
| 巻 | 24巻 |
| 号 | 2号 |
| 開始ページ | 41 |
| 終了ページ | 47 |
| ISSN | 0475-0071 |
| 言語 | 英語 |
| 論文のバージョン | publisher |
| NAID | 120002307289 |