534 research outputs found

    Control and analysis of a unified power flow controller

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    This paper presents a control scheme and comprehensive analysis for a unified power flow controller (UPFC) on the basis of theory, computer simulation and experiment. This developed theoretical analysis reveals that a conventional power feedback control scheme makes the UPFC induce power fluctuation in transient states. The conventional control scheme cannot attenuate the power fluctuation, and so the time constant of damping is independent of active and reactive power feedback gains integrated in its control circuit. This paper proposes an advanced control scheme which has the function of successfully damping out the power fluctuation. A UPFC rated at 10 kVA is designed and constructed, which is a combination of a series device consisting of three single-phase pulsewidth modulation (PWM) converters and a shunt device consisting of a three-phase diode rectifier. Although the dynamics of the shunt device are not included, it is possible to confirm and demonstrate the performance of the series device. Experimental results agree well with both analytical and simulated results and show viability and effectiveness of the proposed control scheme </p

    Integrodifferential equation which interpolates the heat equation and the wave equation

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    Recently many authors have studied the following integrodifferential equa-tion: (0.1) u(t, x) = φ(x)+[&apos;h(t—s)Au(sy x)ds *&gt; 0, χ(Ξ

    Instrumental Resolution of the Chopper Spectrometer 4SEASONS Evaluated by Monte Carlo Simulation

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    We performed simulations of the resolution function of the 4SEASONS spectrometer at J-PARC by using the Monte Carlo simulation package McStas. The simulations showed reasonably good agreement with analytical calculations of energy and momentum resolutions by using a simplified description. We implemented new functionalities in Utsusemi, the standard data analysis tool used in 4SEASONS, to enable visualization of the simulated resolution function and predict its shape for specific experimental configurations.Comment: 8 pages, 5 figure

    On the sets of maximum points for generalized Takagi functions

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    Let φ be a continuous and periodic function on ℝ with period 1 and φ(0)=0. We consider the generalized Takagi function ƒφ defined by ƒφ(x)=Σ[n=0,∞]1/2ⁿφ(2ⁿx) and the set Mᵩ of maximum points of ƒᵩ in the interval [0,1]. When φ₀(x) is the function defined by the distance from x to the nearest integer, ƒᵩ₀ is just the Takagi function. Our aim is to seek a condition on φ in order that Mᵩ⊂Mᵩ₀

    Zero-energy edge states and their origin in particle-hole symmetric systems: symmetry and topology

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    We propose a criterion to determine the existence of zero-energy edge states for a class of particle-hole symmetric systems. A loop is assigned for each system, and its topology and a symmetry play an essential role. Applications to d-wave superconductors are demonstrated.Comment: 2 pages, Proceedings of LT2

    New sharp Gagliardo-Nirenberg-Sobolev inequalities and an improved Borell-Brascamp-Lieb inequality

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    We propose a new Borell-Brascamp-Lieb inequality which leads to novel sharp Euclidean inequalities such as Gagliardo-Nirenberg-Sobolev inequalities in R^n and in the half-space R^n\_+. This gives a new bridge between the geometric pont of view of the Brunn-Minkowski inequality and the functional point of view of the Sobolev type inequalities. In this way we unify, simplify and results by S. Bobkov-M. Ledoux, M. del Pino-J. Dolbeault and B. Nazaret

    The Right to Fair Hearing in Japanese Administrative Law

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    The right to fair hearing in contemporary Japanese administrative law is a tender plant, lacking deep roots in historical tradition, and struggling for survival in a relatively hostile environment, Fair hearing was a concept practically unknown to the administrative law of pre-war Japan, which, taking its cue from German and French law, relied principally, not on the procedural rights of the individual, but rather upon the skill and dedication of administrators for the achievement of efficiency and justice, with only occasional judicial review by the Administrative Court. The Anglo-American maxim that he who decides must hear was indeed foreign to most Japanese administrators. After the war, however, Japanese constitutional revision emphasized individual rights and duties, and prescribed many procedural guarantees for the judicial process; at the same time, various regulatory and welfare statutes introduced the Anglo-American concepts of notice and hearing, or audi alteram partem, into the Japanese administrative process