JaLCDOI 10.18926/15468
FullText URL Mem_Fac_Eng_OU_23_1_69.pdf
Author Totsuji, Hiroo| Takei Makoto|
Abstract The statistical properties of two-dimensional systems of charges in semiconductor superlattices are analyzed and the dispersion relation of the plasma oscillation is calculated. The possibility to excite these oscillations by applying the electric field parallel to the structure is discussed.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1988-11-22
Volume volume23
Issue issue1
Start Page 69
End Page 82
ISSN 0475-0071
language English
File Version publisher
NAID 120002307988
JaLCDOI 10.18926/15467
FullText URL Mem_Fac_Eng_OU_23_1_61.pdf
Author Yamamoto, Yoshitake| Yamamoto, Tatsuma|
Abstract Skin impedance satisfies the Cole-Cole arc's law. The change of skin impedance during GSR (Galvanic Skin Reflex) can be expressed by the change of equivalent parallel resistance approximately. Using these characteristics, the complicated change of skin impedance during GSR can be determined continuously from the measurement value in one frequency point.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1988-11-22
Volume volume23
Issue issue1
Start Page 61
End Page 68
ISSN 0475-0071
language English
File Version publisher
NAID 120002307322
JaLCDOI 10.18926/15465
FullText URL Mem_Fac_Eng_OU_23_1_49.pdf
Author Oka, Hisao| Yamamoto, Tatsuma| Isayama Yoshiharu|
Abstract In the field of dental study it is most fundamental and necessary to estimate the condition of periodontium. In order to examine a mechanical characteristics of periodontium, the theoretical displacement response to periodontal mechanical model (three elements model) are strictly solved in case of some pulse excitations. Impact excitations (rectangular, triangular and half-cycle sine pulse) are given in physical and mathematical definitions and complete solutions to the impact excitations are provided. The triangular pulse excitation which is obtained by means of a fracture of pencil-lead is most suitable. The mechanical parameters of periodontium are given using this input excitation. This is experimentally confirmed by artificial tooth model. The obtained mechanical characteristic of the periodontal tissues can be applied to clinical diagnosis.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1988-11-22
Volume volume23
Issue issue1
Start Page 49
End Page 60
ISSN 0475-0071
language English
File Version publisher
NAID 120002307622
JaLCDOI 10.18926/15462
FullText URL Mem_Fac_Eng_OU_23_1_39.pdf
Author Osaka, Akiyoshi| Yuasa Motokazu| Miura, Yoshinari| Takahashi, Katsuaki|
Abstract Sodium borosilicate gels of compositions similar to that of Vycor(R) glass like 80SiO(2).15B(2)O(3).5Na(2)O (wt%) were prepared from hydrolysis and polycondensation of metal alkoxides under the HCl catalysis. Variation of specific surface area and porosity with temperature indicated that closed pores were opened below 400℃, and collapsed above 450℃ after the porosity reached a maximum value around 450℃. The structural evolution was examined due to IR spectra and a phase separation in the gels was observed. The solubility of the gels into 1N-HCl was studied as a function of the treatment temperature.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1988-11-22
Volume volume23
Issue issue1
Start Page 39
End Page 48
ISSN 0475-0071
language English
File Version publisher
NAID 120002307518
JaLCDOI 10.18926/15459
FullText URL Mem_Fac_Eng_OU_23_1_31.pdf
Author Miura, Yoshinari| Yuasa Motokazu| Osaka, Akiyoshi| Takahashi, Katsuaki|
Abstract Sodium borosilicate gels of compositions similar to that of Vycor(R) glass like 80SiO(2).15B(2)O(3).5Na(2)O(wt%) were prepared from hydrolysis and polycondensation of tetraethyl orthosilicate, trimethyl borate, and sodium methylate under the HCl catalysis. Variation of the gelation time is examined as a function of the mixing ratio of the starting materials and the catalyst. The thermal behavior of the gels has been discussed on the basis of their TG and DTA traces.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1988-11-22
Volume volume23
Issue issue1
Start Page 31
End Page 38
ISSN 0475-0071
language English
File Version publisher
NAID 120002307464
JaLCDOI 10.18926/15455
FullText URL Mem_Fac_Eng_OU_23_1_1.pdf
Author Matsuda, Masaaki| Osaki, Hirokazu|
Abstract Display equipment has been used as communication media in the factory, office, and home. In order to communicate effectively, it is necessary to clarify the characteristics of eye movement in the case of looking at the display. The development of Eye Camera enables us to measure eye movement during work, so that we can collect the many data of eye movement during work. In this study, we proposed a method to evaluate the visual work using the distribution of visual points in X and Y axis. The cumulative distribution is approximated by the logistic curve which shows the symmetry and kurtosis by the parameter. The proposed method was applied to the three typical display models, that is, the digital meter model, reading model, and game model. In the digital meter model, the visual points were distributed symmetrically along the meters, and the symmetry and kurtosis of the distribution varied by the arranged direction of the meter. In the reading model, the visual points were distributed nearly symmetrically and uniformly in each axis and they were moved around the character and line from the period of spectrum analysis. In the game model, the visual points moved according to the target and were distributed symmetrically in the Y axis. And whether the target moved vertically or horizontally, the kurtosis of the distribution became equal in each axis.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1988-11-22
Volume volume23
Issue issue1
Start Page 1
End Page 12
ISSN 0475-0071
language English
File Version publisher
NAID 120002307354