JaLCDOI 10.18926/15470
FullText URL Mem_Fac_Eng_OU_24_1_13.pdf
Author Uno, Yoshiyuki| Nakajima, Toshikatsu| Endo, Osamu|
Abstract The generation mechanism of crater in electrical discharge machining is analyzed with a single pulse discharge device for alloy tool steel, black alumina ceramics, cermet and cemented carbide, investigating the gap voltage, the discharge current, the shape of crater, the wear of electrode and so on. The experimental analysis makes it clear that the shape of crater has a characteristic feature for the kind of workpiece. The shape of electrode, which changes with the wear by an electric spark, has a significant effect on the shape of crater. The diameter and the depth of crater have a close relation to the discharge energy for alloy tool steel, black alumina ceramics and cermet, while those for cemented carbide are related to the discharge current. The shape factor which is the ratio of the depth to the diameter of crater is different for the work material.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1989-11-29
Volume volume24
Issue issue1
Start Page 13
End Page 24
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307269
JaLCDOI 10.18926/15471
FullText URL Mem_Fac_Eng_OU_24_1_25.pdf
Author Kajihara, Yasuhiro| Osaki, Hirokazu|
Abstract An expert system, in which preconditions and rules are expressed in logical formulas, is developed to support the scheduling of an automated job shop type multi-item assembly line. This system has the foIIowing characteristics to apply any case of schedulings: (1)Forward scheduling orbackward scheduling can be made. (2)The criterion on the input order of products, the dispatching process at each assembly station, and the selection of products from a buffer can be selected from several priority criteria. (3)Layout, number and velocity of vehicles, and the capacity of each buffer can be changed.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1989-11-29
Volume volume24
Issue issue1
Start Page 25
End Page 39
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307454
JaLCDOI 10.18926/15472
FullText URL Mem_Fac_Eng_OU_23_2_9.pdf
Author Kuroda Tsutomu| Osaki, Hirokazu| Matsuda, Masaaki| Fujisawa Keita|
Abstract Multi-item flexible manufacturing systems have been spread to correspond the short life-cycle and the diversification of products. Part handling plays an important role to operate multi-functional robot efficiently in these systems, and many jigs are widely used to hold a part. They should be exchanged at once according to changing products. In this paper, we propose a pin jig which holds a part with two pins, and design method of the position, length and diameter of those pins for a cylindrical part. This jig has the following characteristics. As a surface of the jig is inclined to use gravity, the part can be fixed without any external forces. Therefore the structure of jig becomes simple, and loading and unloading of a part becomes easy for a robot hand.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1989-03-30
Volume volume23
Issue issue2
Start Page 9
End Page 19
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307693
JaLCDOI 10.18926/15475
FullText URL Mem_Fac_Eng_OU_23_2_21.pdf
Author Myojin Sho| Yamada Masahito| Fujii Naoto|
Abstract Diversion model and disaggregate behavioral model of logit type are adopted as aggregate and disaggregate estimates, respectively. Diversion model is assumed as a binary choice process including diversion ratio function at each step in the process. Diversion ratio is assumed as a function of generalized-travel-time ratio. The function is identified with each of the two steps of diversion; diverson from rail and bus to car at first and from the rest undiverted to bus at second. The data used are those on inter-regional occupational person trips. Each function are found enough and/or critically significant in the statistical sense. At the begginning, sixteen characteristics variables are enrolled in disaggregate model, which are identified by use of the above data. Six variables are reached finally and are all reasonable. A brief comparison of goodness of fit to the data are made between two models.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1989-03-30
Volume volume23
Issue issue2
Start Page 21
End Page 32
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307168
JaLCDOI 10.18926/15477
FullText URL Mem_Fac_Eng_OU_23_2_33.pdf
Author Ishihara Yuji| Yamamoto, Kyoji|
Abstract This paper deals with the low Mach numbers flow of a rarefied vapour past a liquid sphere accompanied with condensation and evaporation at its surface. The linearized Bhatnager-Gross-Krook(B-G-K} equation is used for the analysis, and from it the integral equations of the density, temperature and flow velocities are derived. These integral equations are solved numerically over a wide range of the Knudsen number covering from the slip flow to the nearly free molecular flow. The drag on the sphere is also calculated and is compared with that of previous work.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1989-03-30
Volume volume23
Issue issue2
Start Page 33
End Page 44
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307401
JaLCDOI 10.18926/15478
FullText URL Mem_Fac_Eng_OU_23_2_45.pdf
Author Taniguchi, Takeo| Fujiwara, Kohji|
Abstract This paper includes a solver for a large sparse set of linear algebraic equations which are obtained by the application of the finite element method to static structural problems. Proposed method is a modification of Robust Incomplete Choleski-Conjugate Gradient Method, which belongs to Preconditioned Conjugate Gradient Method suitable for supercomputers. Through a number of numerical experiments the authors show that Robust Incomplete Choleski-Conjugate Gradient Method sometimes fails in to obtain the solutions, secondly they clarify the reason of the failures from the theoretical viewpoint, and finally they propose a modification of the robust method by the introduction of the theoretical result. Proposed method is as effective as the original, and it can overcome the demerit of Robust Method which is clarified through numerical experiments.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1989-03-30
Volume volume23
Issue issue2
Start Page 45
End Page 55
ISSN 0475-0071
language 日本語
File Version publisher
NAID 120002307820
JaLCDOI 10.18926/15480
FullText URL Mem_Fac_Eng_OU_25_1_1.pdf
Author Gao Hong| Wada, Tsutomu| Noritsugu, Toshiro|
Abstract 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.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1990-12-14
Volume volume25
Issue issue1
Start Page 1
End Page 13
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002308010
JaLCDOI 10.18926/15481
FullText URL Mem_Fac_Eng_OU_24_1_81.pdf
Author Wada, Osami|
Abstract Are calculated the radiation characteristics of two types of primary-feed waveguides of millimeter wave quasi-optical antennas, which transform circular TE(On) mode into a linearly polarized beam. These antennas are utilized for heating and diagnostics of fusion plasma. Analysis is based on the Huygens-Fresnel principle, which takes the diffraction effect into account. For Convenience in analysis, a feed waveguide is divided into two sections, an uniform waveguide section and a visor section. Assuming that the diameter of the waveguide is several times as large as the wavelength and that the structure of the visor is open, the radiation field is approximated by superposition of direct radiation, and first and second reflection on the visor. Numerical results are presented and compared with experimental results. In these types of waveguides, the shadow section on the visor has a great influence on the radiation field. The results of calculation show that the length of the visor should be longer than that obtained by the geometrical optics, and the longer visor reduces the side-lobe level in the direction of the waveguide axis. The results agree well with those in experiments.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1989-11-29
Volume volume24
Issue issue1
Start Page 81
End Page 92
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307974
JaLCDOI 10.18926/15482
FullText URL Mem_Fac_Eng_OU_24_1_93.pdf
Author Totsuji, Hiroo| Hatatani, Teruki|
Abstract Propagation of charged carriers in semiconductor superlattices is analyzed on the basis of the effective mass approximation with appropriate boundary conditions at heterojunctions taken into account. Applying the finite element method, clarified are the effects of details of the potential profile, such as linear and smooth gradings and random fluctuations, on characteristics of superlattices which are expected to work as collector barriers and energy filters in electronic devices.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1989-11-29
Volume volume24
Issue issue1
Start Page 93
End Page 105
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307513
JaLCDOI 10.18926/15484
FullText URL Mem_Fac_Eng_OU_25_1_15.pdf
Author Sakakibara, Akira| Kanadani, Teruto|
Abstract Aging of Al-lmass % Ag alloy at 273K after quenching under various conditions was studied by measurement of electrical resistivity. Scattering of the quasi-equilibrium value of resistivity (p(e)) was not random but closely related to the as-quenched value (p(o)); P(e) increased with increasing p(o)' When the quenching temperature (T(q)) was lower than or equal to 773K, the state at p(e) was controlled substantially by the concentration of quenched vacancy. On the other hand, when T(q)>823K, GP zones formed during quenching played an important role, instead of quenched vacancies, in determining the state.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1990-12-14
Volume volume25
Issue issue1
Start Page 15
End Page 21
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307255
JaLCDOI 10.18926/15485
FullText URL Mem_Fac_Eng_OU_24_1_115.pdf
Author Abe, Hirofumi| Nogata Mikio|
Abstract The rapid economic growth of Japan in the postwar period has brought about the over-concentration of activities in a few large cities, and local regions have been losing their economic vitality due to the regional differentials and the population loss. Regional development planning in Japan has sought to achieve a balanced growth of the nation through the development of industries in local regions. This paper aims to examine the regional structure of manufacturing industries in the postwar period and to identify its current problems. Three methods, namely the analysis of coefficient of variation, the rateshare analysis and the shift-share analysis are applied using employment data of manufacturing industries for the years 1955 to 1985. Findings show that while the employment of manufacturing industries has been markedly decentralized from metropolitan to local regions, the disparities in growth rates still exist among regions.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1989-11-29
Volume volume24
Issue issue1
Start Page 115
End Page 133
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307659
JaLCDOI 10.18926/15487
FullText URL Mem_Fac_Eng_OU_24_1_135.pdf
Author Taniguhi, Takeo| Suetsugu, Tsuyoshi| Iwasaki Masaki|
Abstract This paper describes the numerical simulation method of the multi-crack propagation behaviour which appear in a part of civil engineering structures with complex geometrical configuration like steel bridges. Proposed method can treat the interaction of several cracks which locate in a short distance each other, and the process of their growth can be grasped. The method is based on the finite element method, and the linear fracture mechanics is assumed. Proposed method includes following tools for the simulation of the crack propagation behaviour: Automatic Mesh Generators for 3-D, 2-D structural analysis, and 2-D crack propagation analysis, Multi-level Structural Analysis Technique, Estimation Method of the crack growth and the angle of cracks and the modelling method of traffic loadings. The validity of the method is investigated by comparing the result to the experimental one.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1989-11-29
Volume volume24
Issue issue1
Start Page 135
End Page 152
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307854
JaLCDOI 10.18926/15490
FullText URL Mem_Fac_Eng_OU_25_1_51.pdf
Author Totsuji, Hiroo|
Abstract The superconductivity proximity effect in the dirty limit is revisited and equations and boundary conditions are obtained for the case of inhomogeneous media with continuously varying characteristic parameters.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1990-12-14
Volume volume25
Issue issue1
Start Page 51
End Page 57
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307188
JaLCDOI 10.18926/15491
FullText URL Mem_Fac_Eng_OU_24_2_11.pdf
Author Sakakibara, Akira| Kanadani, Teruto|
Abstract Aging behavior of Al-0.23mass % Si alloy was studied by measurements of elecrical resistivity. Resistvity maximum was observed in the aging curves at 273K after quenching from various temperatures. Appearance of maximum and its dependence on the quenching temperature were attributed to the formation of GP zones. Even in a more dilute alloy as 0.01mass % Si, the maximum of resistivity was also recognized.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1990-03-29
Volume volume24
Issue issue2
Start Page 11
End Page 16
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307615
JaLCDOI 10.18926/15493
FullText URL Mem_Fac_Eng_OU_24_2_17.pdf
Author Konishi, Tadataka| Baba, Mitsuru|
Abstract 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.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1990-03-29
Volume volume24
Issue issue2
Start Page 17
End Page 30
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307431
JaLCDOI 10.18926/15494
FullText URL Mem_Fac_Eng_OU_25_1_71.pdf
Author Myojin Sho| Yamada Masahito| Fujii Naoto|
Abstract 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.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1990-12-14
Volume volume25
Issue issue1
Start Page 71
End Page 87
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307618
JaLCDOI 10.18926/15496
FullText URL Mem_Fac_Eng_OU_25_1_89.pdf
Author Abe, Hirofumi| Oishi Manabu|
Abstract 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.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1990-12-14
Volume volume25
Issue issue1
Start Page 89
End Page 98
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307404
JaLCDOI 10.18926/15497
FullText URL Mem_Fac_Eng_OU_24_2_41.pdf
Author Totsuji, Hiroo|
Abstract 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.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1990-03-29
Volume volume24
Issue issue2
Start Page 41
End Page 47
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307289
JaLCDOI 10.18926/15499
FullText URL Mem_Fac_Eng_OU_24_2_49.pdf
Author Mori, Chuji| Machida Ken-ichi|
Abstract 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.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1990-03-29
Volume volume24
Issue issue2
Start Page 49
End Page 65
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307544
JaLCDOI 10.18926/15502
FullText URL Mem_Fac_Eng_OU_24_2_79.pdf
Author Sato, Yoichiro|
Abstract 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.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1990-03-29
Volume volume24
Issue issue2
Start Page 79
End Page 87
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307486