JaLCDOI 10.18926/15492 河野 伊一郎| 西垣 誠| Okada Junji| In this paper, we propose a method to determine the coefficients of permeability of the unconfined aquifer consisted of two different permeability layers. With mixing the conventional pumping test and falling head permeability test, the coefficients of permeabilitiy k(1) and k(2) were obtained. The validity of the proposed method is investigated by using the numerical simulation. As the results, it becomes apparent that the proposed method is applicable to real hydarulic problems. Memoirs of the Faculty of Engineering, Okayama University 1990-12-14 25巻 1号 59 69 0475-0071 English publisher
JaLCDOI 10.18926/15480 Gao Hong| 和田 力| 則次 俊郎| 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. Memoirs of the Faculty of Engineering, Okayama University 1990-12-14 25巻 1号 1 13 0475-0071 English publisher
JaLCDOI 10.18926/15496 阿部 宏史| Oishi Manabu| 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. Memoirs of the Faculty of Engineering, Okayama University 1990-12-14 25巻 1号 89 98 0475-0071 English publisher
JaLCDOI 10.18926/15488 Bouzidi, Moncef| 古賀 隆治| 和田 修己| 香川 直己| Hai, Xu| 小坂 恵| Sano, Hiroya| Is proposed a tunable diode laser absorption spectrometer system which employs a pulsed current to drive the diode laser still implementing a second-harmonic detection methods enhancing a signal to noise up to 104 times that the case without it. This system affords the lead-salt diode laser a higher operating temperature which allows a more compact deep cooling system. A principle is based on employing a gated integrator between the preamplifier and the lock-in amplifier. Investigations are made on the optimum selection of the gating aperture time interval as determined by response time of the infrared detector and the pulse width of the laser driving current. Memoirs of the Faculty of Engineering, Okayama University 1990-12-14 25巻 1号 37 50 0475-0071 English publisher
JaLCDOI 10.18926/15494 Myojin Sho| Yamada Masahito| Fujii Naoto| 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. Memoirs of the Faculty of Engineering, Okayama University 1990-12-14 25巻 1号 71 87 0475-0071 English publisher
JaLCDOI 10.18926/15498 西垣 誠| 竹下 祐二| 河野 伊一郎| 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. Memoirs of the Faculty of Engineering, Okayama University 1990-12-14 25巻 1号 99 109 0475-0071 English publisher
JaLCDOI 10.18926/15508 Nsunge Felix Chintu| 冨田 栄二| 浜本 嘉輔| 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). Memoirs of the Faculty of Engineering, Okayama University 1991-03-28 25巻 2号 25 38 0475-0071 English publisher
JaLCDOI 10.18926/15515 Totsuji, Hiroo| Ishikura Satoshi| Takayama Norihisa| 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. Memoirs of the Faculty of Engineering, Okayama University 1991-03-28 25巻 2号 95 113 0475-0071 English publisher
JaLCDOI 10.18926/15516 谷口 健男| Irie Hirotsugu| 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. Memoirs of the Faculty of Engineering, Okayama University 1991-03-28 25巻 2号 115 122 0475-0071 English publisher
JaLCDOI 10.18926/15506 榊原 精| Kanadani, Teruto| Kaneeda, Toshiaki| Hosokawa, Norio| 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. Memoirs of the Faculty of Engineering, Okayama University 1991-03-28 25巻 2号 17 23 0475-0071 English publisher
JaLCDOI 10.18926/15517 Taniguchi, Takeo| Ohta, Chikashi| 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. Memoirs of the Faculty of Engineering, Okayama University 1991-03-28 25巻 2号 123 133 0475-0071 English publisher
JaLCDOI 10.18926/15500 Okada, Hiroyuki| 飛田 守孝| 榊原 精| 竹元 嘉利| 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. Memoirs of the Faculty of Engineering, Okayama University 1991-03-28 25巻 2号 1 8 0475-0071 English publisher
JaLCDOI 10.18926/15512 Tsuchiya Takao| 加川 幸雄| 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. Memoirs of the Faculty of Engineering, Okayama University 1991-03-28 25巻 2号 69 80 0475-0071 English publisher
JaLCDOI 10.18926/15511 Ohkura Akira| 亀山 嘉正| 佐山 隼敏| 鈴木 和彦| Fukumoto Shuichi| 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. Memoirs of the Faculty of Engineering, Okayama University 1991-03-28 25巻 2号 55 67 0475-0071 English publisher
JaLCDOI 10.18926/15513 Totsuji, Hiroo| 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. Memoirs of the Faculty of Engineering, Okayama University 1991-03-28 25巻 2号 81 93 0475-0071 English publisher
JaLCDOI 10.18926/15503 Mikuni, Masato| 飛田 守孝| Nishida, Norihide| 榊原 精| 山田 益男| 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. Memoirs of the Faculty of Engineering, Okayama University 1991-03-28 25巻 2号 9 15 0475-0071 English publisher
JaLCDOI 10.18926/15510 Nsunge Felix Chintu| 冨田 栄二| 浜本 嘉輔| 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. Memoirs of the Faculty of Engineering, Okayama University 1991-03-28 25巻 2号 39 54 0475-0071 English publisher
JaLCDOI 10.18926/15414 冨田 栄二| Nsunge Felix Chintu| 浜本 嘉輔| Distributions of hydrogen gas concentration in a suddenly started, single shot hydrogen gas jet issuing from a 1 mm diameter injector into still air were measured using laser interferometry method. This unsteady, turbulent free jet flow has also been calculated using the two-equation, high Reynolds number version of k-ε turbulence model and hybrid scheme for treating combined diffusion and convection in the SIMPLE algorithm. The injection pressure was 0.5 MPa for which predicted and measured temporal jet tip penetration distributions indicate that the jet discharged into still air at Mach 0.25. The level of agreement between present prediction and measurement is good in some regions and poor in others. Memoirs of the Faculty of Engineering, Okayama University 1991-11-30 26巻 1号 27 41 0475-0071 English publisher
JaLCDOI 10.18926/15423 川上 浩司| 小西 忠孝| This paper describes a method to construct IDEA BANK automatically. IDEA BANK is the data base of the "function-structure module" which is utilized in systematic conceptual design from Value Engineering perspectives. The method based on the Machine Learning EBL technique was evaluated and implemented for the IDEA BANK using SUN workstation. The practical implementation of the IDEA BANK acquisition was discussed after elucidating the problem and solution of the EBL technique in engineering design. In the IDEA BANK system, the structural features of an existing article are analyzed by hierarchically organized domain specific knowledge to yield a systematic explanation of how they function and attain their design goals. The explanation resulted in a generalized version of the Functional Diagram used in Value Engineering from which "function-structure module" can be extracted systematically. Memoirs of the Faculty of Engineering, Okayama University 1991-11-30 26巻 1号 95 108 0475-0071 English publisher
JaLCDOI 10.18926/15420 河原 長美| Danno Hideki| Kunimatsu Takao| Lake Biwa is the largest lake in Japan, and one of the most important fresh water resources. The Hino River is the fourth largest river among the rivers which flow into Lake Biwa. The eutrophication of the lake has been warned since the 1960s. In order to improve the water quality of the lake, to decrease the loads through rivers is inevitable. Therefore, it is needed to predict the effects of measures to control pollutant loads and the influence of development in the basin on the loads from rivers before developing the basin and taking measures. This paper deals mainly with the model of water quality management for the Hino River and the effects of the development in the basin on the water quality. The model was formulated considering loads from forests, rice paddy fields, households, housing land, industrial factories. Using this model, a calculation system by a microcomputer was developed and the influence of urbanization of the basin was discussed. Memoirs of the Faculty of Engineering, Okayama University 1991-11-30 26巻 1号 61 73 0475-0071 English publisher