JaLCDOI 10.18926/15733
FullText URL Mem_Sch_Eng_OU_12_129.pdf
Author Myojin Syo| Tatsuta Akira| Taka Yasuhisa| Asai Kazuhiko|
Abstract A statistical analysis is applied to find what states of "block" are dangerous from view point of traffic accident. Here, the block is defined to be an area surrounded by some major streets and is feeded by a minor street network. The accidents under study are those which occur in the whole minor street network. They are grouped into three kinds; pedestrian, vehicle and the gross accidents. And each is classified to three types according to the place where the accident occurs. At the beginning 22 variables are assumed to state a certain relationship of some states of the block with the occurrences of accidents and 12 variables are found significant finally through factor analysis. Further examination has reached several key variables that migth have something significant to cause traffic accidents in the block. The key ones are the number of lanes of street and the number of legs of intersection, especially nearly 2 lanes street and 3-leg intersection, respectively. The case study was carried out on 26 blocks sampled from Osaka City.
Publication Title Memoirs of the School of Engineering, Okayama University
Published Date 1978-02-25
Volume volume12
Start Page 129
End Page 139
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307311
JaLCDOI 10.18926/15731
FullText URL Mem_Sch_Eng_OU_12_97.pdf
Author Kono Iichiro| Nishigaki Makoto|
Abstract The solutions of unsteady phreatic flow toward a partially penetrating well in an aquifer of finite thickness are described. Firstly the solution for a confined aquifer is shown. In this case,three methods of analyzing field data with partially penetrating well are given, that is, "Log-Log Method, Log-Log Distance Drawdown Method and Jacob's Method Ajusted for Partial Penetration". By using these methods the hydraulic conductivities and the specific storage of the aquifer may be determined. Secondly the solution for an,unconfined aquifer is shown. In this case, also two methods of analyzing field data with partially penetrating well are given. By using these methods, the anisotropic permeability and the storage coefficient (effective porosity) of the aquifer may be determined. Moreover in each case, the effects of partial penetration are discussed and the limits of adapting the Theis' and Jacob's methods are setted. From these analytic results, some cosiderations are added to determine the anisotropy of permeability and to evaluate the storage coefficient.
Publication Title Memoirs of the School of Engineering, Okayama University
Published Date 1978-02-25
Volume volume12
Start Page 97
End Page 128
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307830
JaLCDOI 10.18926/15730
FullText URL Mem_Sch_Eng_OU_12_89.pdf
Author Totsuji Hiroo|
Abstract The pair correlation function and the correlation energy density of two-dimensional electron liquids are calculated on the basis of the Salpeter's Debye-chain type expansion. When the two-dimensional plasma parameter (£=2πne4T-2) is small, the expansion to the first order gives the correlation energy to the order of (£21n£). It is shown that experimental results in the domain (£<0.5) can be reproduced by taking into account the first and the second order terms in this expansion.
Publication Title Memoirs of the School of Engineering, Okayama University
Published Date 1978-02-25
Volume volume12
Start Page 89
End Page 96
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307196
JaLCDOI 10.18926/15727
FullText URL Mem_Sch_Eng_OU_12_77.pdf
Author Ohta, Mutsuo| Kobayashi, Toshinori| Sakakibara, Akira|
Abstract The clustering phenomenon was observed when dilute Al-Zn alloys were annealed at temperatures higher than the solvus of the G.P.zones. In this report the apparent activation energy for clustering is estimated and compared with the experimental results. The estimated value of the apparent activation energy for clustering in several Al-Zn alloys comes to 0.51 eV, which is larger than the effective migration energy 0.43 eV of Zn atoms in Al-Zn alloys.
Publication Title Memoirs of the School of Engineering, Okayama University
Published Date 1978-02-25
Volume volume12
Start Page 77
End Page 88
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307178
JaLCDOI 10.18926/15725
FullText URL Mem_Sch_Eng_OU_12_59.pdf
Author Ohta, Mutsuo| Kanadani, Teruto| Sakakibara, Akira|
Abstract Several Al-Zn alloys containing 0.041-4.4 at % Zn were studied by means of measurements of electrical resistivity. The results obtained are as follows : (1) The electrical resistivity increases when the specimen is annealed at temperatures higher than the solvus temperature of the G.P. zones. The increase of the resistivity is due to the formation of fluctuation. (2) The electrical resistivity of the specimen containing fluctuation is dependent upon annealing temperature only and independent of quenching temperature. (3) The fluctuation is formed in very dilute alloys as 0.041 at % Zn at temperatures higher than the solvus temperature of the G.P. zones. (4) The formation energy of vacancy and the migration energy of the Zn atom in the alloys determined by the formation process of fluctuation are in good agreement with those by the formation process of G.P. zones. (5) In spite of the result (4), it seems that the fluctuation is not the same as the small G.P. zones which are observed in the early stage of aging.
Publication Title Memoirs of the School of Engineering, Okayama University
Published Date 1978-02-25
Volume volume12
Start Page 59
End Page 75
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307636
JaLCDOI 10.18926/15721
FullText URL Mem_Sch_Eng_OU_12_53.pdf
Author Fujitsuka Takeshi| Agusa Toru|
Abstract In recent years, the development of a high power transistor element is proceeding. A high power inverter circuit using power transistors are finding a good number of applications in induction heating and melting. Turn off time of power transistors occupies 5-lOμs of switching characteristics. A driving method to give base inputs for a half period is widely used for a inverter circuit. But this method has the following defects, the short-circuit current flows through two transistors because the other pair transistors turn on before one pair transistors turn off. So the switching loss is increased, the maximum output and the efficiency are decreased. In this paper, a driving method to give base inputs for the less period as compared with a half period is discussed. Using this method, the foregoing defects is lost and the driving frequency is able to become higher. In addition, it become clear that the square waveform output is given using this method in the case of R-L load.
Publication Title Memoirs of the School of Engineering, Okayama University
Published Date 1978-02-25
Volume volume12
Start Page 53
End Page 58
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307552
JaLCDOI 10.18926/15720
FullText URL Mem_Sch_Eng_OU_12_45.pdf
Author Himei Toyoji| Nakanishi Senichiro| Funabiki Shigeyuki|
Abstract In this paper, an AC chopper circuit, using a power transistor, is described which chops the AC voltage with a commercial frequency. The circuit is composed of a diode bridge and a power transistor in series with a load and capable of adjusting the switching frequency, fc, and the time ratio, T=ton/(ton+toff). The switching frequency and the time ratio of the AC chopper circuit depend on switching-times, that is, delay time, rise time, carrier storage time and fall time, especially in the high frequency. The upper limit of the switching frequency (about 150kHz) and the output characteristics of the circuit are investigated.
Publication Title Memoirs of the School of Engineering, Okayama University
Published Date 1978-02-25
Volume volume12
Start Page 45
End Page 52
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307334
JaLCDOI 10.18926/15716
FullText URL Mem_Sch_Eng_OU_12_29.pdf
Author Yamamoto Tatsuma| Yamamoto Yoshitake| Nishida Hideki| Yasuhara Kiyotaka|
Abstract The distributed circuit properties based on pores in the etched aluminum oxide film of the electrolytic capacitor have been analysed by the mathematical equation. This paper proposes the selection and the determining method of the parameters appearing in the analysis.
Publication Title Memoirs of the School of Engineering, Okayama University
Published Date 1978-02-25
Volume volume12
Start Page 29
End Page 36
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307968
JaLCDOI 10.18926/15714
FullText URL Mem_Sch_Eng_OU_12_23.pdf
Author Yamashita Yuhiko| Monobe Kazuo|
Abstract A new realistic, structural model is proposed for the glassy solid state of poly(ethylene terephthalate) (PET). The model is considered basing on crystallization behaviors from the glassy state of PET, and in particular including the evidence from the estimation of chain folding energy in this report. When PET is quenched from its melt into the glassy state, irregular folds with lower conformational energy remain in glassy structure and disturb the three dimensional arrangement of the chains connected with the folds. In conclusion, we suggested that the structure of glassy PET is not in amorphous state which is represented by the interpenetrating random coil model, but in frozen metastable state which can be approached from the chain folded structure of polymer crystals.
Publication Title Memoirs of the School of Engineering, Okayama University
Published Date 1978-02-25
Volume volume12
Start Page 23
End Page 28
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307771