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Author

Mitsuo Ohta

Other affiliations: Kindai University
Bio: Mitsuo Ohta is an academic researcher from Hiroshima University. The author has contributed to research in topics: Probability distribution & Noise. The author has an hindex of 8, co-authored 185 publications receiving 338 citations. Previous affiliations of Mitsuo Ohta include Kindai University.


Papers
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01 Sep 1968
TL;DR: First, a general expression of multi-dimensional probability density function in the form of orthogonal series such as statistical Hermite expansion is introduced, which is more general than the well-known expansion expression due to Gram Charlier, because it includes the latter.
Abstract: When many correlative random physical proccesses are passed through nonlinear circuit elements such as detectors or rectifiers and the output random fluctuations are considered, the probability variables defined over positive region are fundamental quantities of engineering interest. First, a general expression of multi-dimensional probability density function in the form of orthogonal series such as statistical Hermite expansion is introduced. This probability expression is more general than the well-known expansion expression due to Gram Charlier, because it includes the latter. Then, as the special case of interest when many correlative physical quantities fluctuating only in positive region are treated, an explicit representation of joint probability density function in the form of statistical Laguerre expansion series is also -presented. Further, it has been pointed out that the latter method using a statistical Laguerre expansion is closely related with the statistical Hermite expansion method under a quadratic nonlinear transformation. We must call our attention to the fact that the statistical meaning 0. e., the random property) is reflected in each expansion coefficient. Finally, the detailed experimental considerations enough to corroborate the above theories are given for the following two cases : (a) a quadratic rectifier with non-Gaussian random input, (b) a non-quadratic rectifier with Gaussian random input.

27 citations

Journal ArticleDOI
TL;DR: In this paper, the laser ablation was applied to a mixed target of CdS and Cu, and the formation of p-type thin film was also confirmed by the photovoltaic effect of the p-n junction.
Abstract: A new method to prepare p-type CdS thin film was investigated, in which the laser ablation was applied to a mixed target of CdS and Cu. The p-type CdS film was obtained from a target containing more than 5 at% Cu. Composition analysis showed that Cu content in the film was about one-fifth of that in target. The formation of p-type CdS film was also confirmed by the photovoltaic effect of the p-n junction which was constructed by laminating n-type CdS film and p-type CdS film.

14 citations

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TL;DR: An extended type regression analysis method hierarchically reflecting various types of correlation information is theoretically derived by introducing an expression on the multi-dimensional probability distribution in an orthogonal expansion series form with discrete level type.

11 citations


Cited by
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Journal ArticleDOI
TL;DR: The theory of residues conformal mapping has been studied in this paper, where the Laplace transformation is used to define a complex variable infinite series in the complex plane, and the calculus of variations analytic functions of the infinite series is studied.
Abstract: Ordinary differential equations of the first order linear differential equations complex numbers and linear algebra simultaneous linear differential equations numerical methods the descriptive theory of nonlinear differential equations mechanical systems and electric circuits Fourier series Fourier integrals and Fourier transforms the Laplace transformation partial differential equations Bessel functions and Legendre polynomials applications and further properties of matrices vector analysis the calculus of variations analytic functions of a complex variable infinite series in the complex plane the theory of residues conformal mapping.

622 citations

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TL;DR: In this article, a brief review of the spin-iIsing model in a transverse field provides a useful description (insulating magnetic systems, order-disorder ferroelectrics, cooperative Jahn-Teller systems and other systems with 'pseudo-spin'- phonon interactions).
Abstract: A brief review is first made of systems for which the spin-iIsing model in a transverse field provides a useful description (insulating magnetic systems, order-disorder ferroelectrics, cooperative Jahn-Teller systems and other systems with 'pseudo-spin'- phonon interactions). A perturbation expansion is then developed which provides for all temperatures an approximate description of the model. The perturbation series is classified with respect to the small parameter l/z, where z is the number of spins interacting with a given spin; this generates the molecular-field approximation and the random-phase approxi- mation as the lowest-order description of the thermodynamic functions and correlation functions respectively. The leading-order approximations for the correlation functions, susceptibilities and spectral functions are discussed in detail. The formalism, which is the first application of such techniques to systems with varying magnetization direction, provides a basis for subsequent higher-order calculations of the free energy and correlation functions.

250 citations

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TL;DR: A fuzzy goal programming approach is applied for the optimal planning of solid waste management systems in a metropolitan region and demonstrates how fuzzy, or imprecise, objectives of the decision maker can be quantified through the use of specific membership functions in various types ofSolid waste management alternatives.

221 citations

Journal ArticleDOI
TL;DR: A new approach a fuzzy interval multiobjective mixed integer programming (FIMOMIP) model is proposed for the evaluation of management strategies for solid waste management in a metropolitan region and demonstrates how uncertain messages can be quantified by specific membership functions and combined through the use of interval numbers in a multiobjectives analytical framework.

120 citations

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TL;DR: In this article, a number of possible doping-limiting mechanisms in II-VI's are critically analyzed, in particular: self-compensation by spontaneous formation of native defects, amphoteric behavior of several potential dopants, lattice relaxation around some doping atoms, insufficient solubility of the others, and the softness of the IIB-VI compounds.

113 citations