著者
伊藤 洋 秋山 郁男村田 嘉利 村田 嘉利
出版者
山梨大学
雑誌
山梨大學工學部研究報告 (ISSN:05131871)
巻号頁・発行日
vol.27, pp.161-166, 1976

When two electromagnetic plane waves of different frequencies, f_1 and f_2,are incident upon a semi-infinite, anisotropic plasma, mixing phenomena of the electromagnetic waves are theoretically considered. For the simplicity, the waves are assumed to be vertically incident upon the plasma, and the static magnetic field is also assumed to be parallel to the direction of the wave propagation. In the plasma, the second order fluctuations of electron density of frequencies 2f_1,2f_2,|f_1±f_2| are excited as well in the anisotropic plasma as in an isotropic case. The plasma resonance of the difference frequency wave takes place, when |f_1-f_2|=f_p, where f_p is the plasma frequency. In this case, the amplitude of the difference frequency wave is affected by the cyclotron frequency of the plasma. And the amplitude becomes larger as the cyclotron frequency becomes higher. The effect of the collision frequency on the resonance phenomenon is also reported in this paper.
著者
内村 桂輔
出版者
山梨大学
雑誌
山梨大學工學部研究報告 (ISSN:05131871)
巻号頁・発行日
vol.36, pp.126-129, 1985

We define a circular Amida lot and evaluate the number of vertices of it needed to represent a permutation.
著者
若林 正 金丸 豊典
出版者
山梨大学
雑誌
山梨大學工學部研究報告 (ISSN:05131871)
巻号頁・発行日
vol.7, pp.73-90, 1956-08-11

Diagrams and slide rules for real numbers are practically used by scholars and engineers every day. These diagrams and slide rules serve speed & easiness in multiplication division and other difficult computations. Now complex numbers are used also in physics and engineering, specially in electric engineering. But the computation of complex numbers are so difficult and trouble some that they often lead many errors & mistakes in calcutation. Then diagrams & slide rules for complex numbers are devised in order to facilitate the computation, and to make it possible to calculate rapidly and to check.
著者
佐々木 大策 荻原 能男
出版者
山梨大学
雑誌
山梨大學工學部研究報告 (ISSN:05131871)
巻号頁・発行日
vol.18, pp.136-144, 1967-12-20

The estimations of this storm runoff on a 0.806km^2 natural catchment by means of (1) hydrograph method (2) continuity method at lake Saiko (3) dynamic equation method have been discribed in this paper. Especially the analysis of the dynamic equation is a new method in which the probable discharge is used. The results of this study indicate that probably peek discharges are 30-100m^3/s water and 500-700m^3/s total.
著者
高村 聡 松本 和教 関口 芳廣
出版者
山梨大学
雑誌
山梨大學工學部研究報告 (ISSN:05131871)
巻号頁・発行日
vol.42, pp.44-50, 1991-12

We are developing a wild birds twitter-identification system which can work in noisy enviroments. In the natural world, there are several types of noises, for example, the sound of stream, the sound of leaves swayed by the wind and twitters of other birds. Then we can't use specific features of the twitters of birds to identify them. In this system, the number of zerocrossing and the mean value of overall spectrum of twitters of birds are used to determine the kind of birds. This system can successfully identify 34 twitters out of 35 twitters which are twittered by 7 kinds of birds and recorded in natural world.