 ID (desc)
JaLCDOI 10.18926/15649 Kaneda Masahiro| This paper deals with a parameter estimation method which yields the more suitable estimate of the parameter using noisy data or measured values. The estimation method is one that uses a kind of a weighted mean, and weighting at taking a weighted mean is interested in particularly. That is to say, as the grade of 'more suitable' depends upon the weighting, we can obtain the more suitable estimate by choosing the weighting coefficients suitablly. When the function which yields the estimate using finite measured values, i.e., the estimator is a particular form, sub-optimal weighting in the practical sense is discussed. Here, the concept of 'optimal' implies that the variance of the final estimate is minimum. And the particular form is one that both the denominator and the numerator of the estimator are first order formulas or second order formulas of finite measured values. And two theorems in relation to this problem are proposed and proved. Moreover, for an exsample of application of these theorems, a parameter estimation method is dealt with, which estimates the parameters of the pulse transfer function of a control system using the sampled measured values of the impulse response of that system. Memoirs of the School of Engineering, Okayama University 1972-07-10 volume7 issue1 43 48 0475-0071 英語 publisher
JaLCDOI 10.18926/15648 Ishii Tadao| A theory, based on Chambers' method to the classical Boltzmann equation, is developed for an acoustic amplification in both degenerate and nondegenerate piezoelectric semiconductors subjected to the Hall geometrically configured electric and magnetic fields. It is found that an amplification constant for qR>1 holds not only for a magnetic field ω(c)τ>1 but for ω(c)τ<1 under ql>1 while the amplification constant for qR<1 does for ql≦1 under　ω(c)τ>1; q is the wave number vector of sound, R the cyclotron radius, ω(c) the cyclotron frequency, 1 the mean free path and τ the relaxation time. A generalized attenuation (amplification) constant is presented through an energy conservation law, being applicable to the sounds propagating at any angle with respect to the particle drift so the off-axis as well as on-axis amplifications are surely involved. An application of the present theory to n-InSb reveals a threshold dependence for the acoustic amplification, which is semi-quantitative agreement with the experimental result of Arizumi et al.. The amplification constant by that nondegenerate particles is found to be almost equal to that by the degenerate ones, provided that the former carrier density should be replaced by its three times as much. Memoirs of the School of Engineering, Okayama University 1972-07-10 volume7 issue1 31 42 0475-0071 英語 publisher
JaLCDOI 10.18926/15647 Sano Hiroya| Tanada Yoshihiro| In the CRT display system of high-speed electromagnetic deflection, the tendency to amplifier saturation should not be neglected. We first show the limitation to the linear characteristics of input-output response and the response time under the saturation condition in this system. We try to improve the frequency-characteristics of the amplifier by making the load resistance constant and the feedback-paths partially positive, and reduce the L/R value of the load circuit by adopting the mutually-coupled yokecoils and the low-current amplifier. As the result, it is suggested that a low-power dissipation and highspeed response electromagnetic deflection system can be constructed. Memoirs of the School of Engineering, Okayama University 1972-06-01 volume7 issue1 25 29 0475-0071 英語 publisher
JaLCDOI 10.18926/15644 Osaki Hirokazu| Kikuchi Susumu| This paper deals with the empirical formula to explain the work amount curve of a worker during a work. The empirical formula yt = at(b) + c was used to explain this phenomenon until now. This formula has been used mainly to approximate to the monotonous trend of the work amount curve. But it was made clear that if the work amount curve showed the polynomial trend, it could not be done so. Then the authors attempt to establish the empirical formula yt = a/{exp(Σb(i)t(i))-l} + c, which was the general form of the logistic curve in order to explain not only the monotonous trend but also the polynomial trend of the work amount curve. And it was made clear from the results of the approximation that this formula was the one of the most usuful formula in order to explain the work amount curve. Memoirs of the School of Engineering, Okayama University 1972-07-10 volume7 issue1 1 9 0475-0071 英語 publisher