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Performance of a web transport system with tension control subsystem using speed as control input
No full text41st Annual Conference of the IEEE Industrial Electronics Society, IECON 2015, Yokohama, Japan, 9-12 Nov. 2015In this paper, the authors improve the control performance of a multi-span web transport system by introducing a new decentralized control strategy using the overlapping decomposition. The system is composed of eleven guide rollers, four main sections mutually interconnected with each other. The overlapping decomposition requires a derivative action on the controlled variables. All the theoretical aspects will be shown together with the preliminary experimental results demonstrating the improvements of the proposed approach
Power module current imaging system by magnetic flux sensor array
Get PDF電子デバイス/半導体電力変換 合同研究会, 10月29日-30日, 2015年, 長崎歴史文化博物館, 長崎県Power modules are required high reliability as energy saving technology. It is important to image current crowding which causes devices destruction. In this study, we developed the 16-channels micro magnetic flux sensor array and the amplifier to realize current imaging in power modules. We report the structure, flat sensitivity technology, noise reduction, data handling program and imaging tool on GUI
Sure Ways to Win a Game ? Nondeterministic Dynamic Programming Approach ?
Get PDFSurefire strategies for winning a two-player pyramid game are found by a nondeterministic dynamic programming approach. The game is simple. Initially, vertical bars are arranged as a lower triangular matrix whose nonzero elements are 1. Two players take turns in marking the bars on the basis of a given set of rules. The player marking the last bar loses. In our dynamic programming formulation, a state denotes the current situation of the player who moves first. The next state depends on the opponent’s unknown decision. In general, the first player must simultaneously consider multiple states in the next turn. Therefore, a dynamic programming formulation of this problem requires nondeterministic transition. We show that the problem becomes equivalent to minimizing the max-add criterion under nondeterministic transition. The optimal solutions then provide the shortest surefire strategies
Simulation of Coming Out of Shaft from the Ceramics Sleeve During Rotation of the Rollers Connected under Small Shrink-Fitting Ratio
No full textIn this paper the loosening and coming out of a roller is considered by using FE analysis when a ceramics sleeve is shrinking fitted to two steel shafts. It should be noted that only small shrink fitting ratio can be applied for the connection because of the brittleness of ceramics. However care should be taken for coming out of the shafts during rotation under such small shrink fitting ratio. In this study therefore the finite element analysis is applied to simulate this behavior. Then, the coming out behavior during rotation can be realized by the simulation where the rotation of the roller is replaced by the shift of the load at an interval of the rotation angle. Under smaller shrink fitting ratio the shaft comes out, but under larger shrink fitting ratio the shaft does not. The effects of the magnitude of the load, friction coefficient, and stiffness of the shaft are also discussed
Catalytic Graphitization for Preparation of Porous Carbon Material Derived from Bamboo Precursor and Performance as Electrode of Electrical Double-Layer Capacitor
Get PDFThe combination of the addition of Fe, which acts as catalyst for graphitization, and CO2 activation, which is a kind of gaseous activation, was performed in order to prepare porous carbon material from bamboo powder which is the waste of superheated steam treatment. Regardless of the heat treatment temperature, many macropores were successfully formed by the removal of the Fe compounds after the heating process. The turbostratic carbon structure generated in the Fe-added sample heated at 850 degrees C. It was confirmed that the added Fe acted as the template for pore formation Moreover, It was confirmed that the added Fe acted as the catalyst for graphitization. The electrochemical performances for the electrode of electrical double layer capacitor, such as cyclic voltammetry, electrochemical impedance spectroscopy, and charge-discharge test, could be explained by the effects of the graphitization and activation. The addition of Fe could affect the electrical property of the carbon material derived from bamboo
Multiplicative Noise-Induced Electrohydrodynamic Pattern Formations by Controlling Electric Conductivity
Get PDFWe report multiplicative noise impacts on electroconvections (ECs) in a nematic liquid crystal. By controlling the intensity and cutoff frequency of a superposed electric noise (on a sinusoidal field for ECs), we investigate the variation in the characteristics of ECs such as thresholds and pattern diagrams in high-conductivity cells (σ ∼ 10−6 Ω−1 m−1), in comparison with that in usual conventional cells (σ ∼ 10−8 − 10−7 Ω−1 m−1). Unpredictable threshold behaviors, unknown pattern formations such as isotropic liquid bubbles and EC-sustained phases, and undesirable dielectric breakdown induced by thermal focusing are found in high-conductivity cells
Decentralized Coefficient Diagram Method Based Robust Frequency Control Design in Power System
Get PDF九州工業大学博士学位論文（要旨） 学位記番号:工博甲第389号 学位授与年月日:平成27年3月25
Design of Practical Superconducting DC Power Cable With REBCO Coated Conductors
Get PDFcritical current density of a superconductor in a parallel magnetic field. It was expected that a cable with a high current-carrying capacity could be realized with REBa2Cu3O7-σ (REBCO) coated conductors. However, the critical current density in most commercial coated conductors does not increase but slightly decreases with increasing parallel magnetic field. Nevertheless, the critical current density in the parallel magnetic field is remarkably higher than that in a normal in-plane magnetic field, and it is possible to construct a dc cable with a higher current-carrying capacity using this characteristic in comparison with conventional superconducting cables. In this paper, we propose a new design of dc power cable suitable for present commercial coated conductors. The optimal condition of the cable is discussed