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991.
Okubo H. Shimizu R. Sawada A. Kato K. Hayakawa N. Hikita M. 《Dielectrics and Electrical Insulation, IEEE Transactions on》1997,4(1):64-70
We measured the electric field in transformer oil/solid composite insulation system under dc voltage application using a Kerr electro-optic measurement system. When a pressboard was inserted at the center between two parallel-plane electrodes, the electric field at the mid-point between the pressboard and the cathode decreased with time. On the other hand, the electric field at the mid-point between the pressboard and the anode increased initially with time, reached a maximum value and then fell down. We measured also the electric field before and after polarity reversal of the dc voltage. The results revealed that the electric field after polarity reversal reached a magnitude 2.7× as much as the average dc applied field. We interpreted the above results on the time transition of the electric field in terms of a charge dynamic model, considering the difference in charge accumulation speed on the pressboard between positive and negative charges. This model was verified to be applicable to the time transition of the electric field in oil/solid composite system and BTA added oil/solid composite system as well 相似文献
992.
本文将通常为圆形的定子截面形状改为三圆弧形,对深井潛水泵用马达的振动特性进行了理论解析和实验研宄。结果表明,正确选择截面形状参数,可有效地提高马达的稳定界限。从而指出了改善深井潛水泵用马达稳定性的一种途径。本文所得结果也可供实际设计深井潛水泵用马达对参考。 相似文献
993.
Amir Azaron Cahit Perkgoz Hideki Katagiri Kosuke Kato Masatoshi Sakawa 《Computers & Operations Research》2009
A genetic algorithm approach is used to solve a multi-objective discrete reliability optimization problem in a k dissimilar-unit non-repairable cold-standby redundant system. Each unit is composed of a number of independent components with generalized Erlang distributions arranged in a series–parallel configuration. There are multiple component choices with different distribution parameters available for being replaced with each component of the system. The objective of the reliability optimization problem is to select the best components, from the set of available components, to be placed in the standby system in order to minimize the initial purchase cost of the system, maximize the system MTTF (mean time to failure), minimize the system VTTF (variance of time to failure) and also maximize the system reliability at the mission time. Finally, we apply a genetic algorithm with double strings using continuous relaxation based on reference solution updating (GADSCRRSU) to solve this multi-objective problem, using goal attainment formulation. The results are also compared against the results of a discrete-time approximation technique to show the efficiency of the proposed GA approach. 相似文献
995.
Lilian Anne Krug Douglas Francisco Marcolino Gherardi José Luiz Stech Zelinda Margarida De Andrade Nery Leão Ruy Kenji Papa De Kikuchi 《International journal of remote sensing》2013,34(13):4059-4074
The relation between climate variability and coral bleaching in the Bahia reefs was investigated in an attempt to characterize the bleaching environments. The following 13-year time series were derived from the remote-sensing, analysis and reanalysis data: maximum summertime sea surface temperature (SST), maximum sea surface temperature (MaxSST) accumulated in 5 days (SSTAc5day), diffuse attenuation coefficient for downward irradiance at 490 nm (K 490), rainfall and magnitude of surface wind fields, including the zonal (U) and meridional components. Principal component analysis, non-metric multidimensional scaling (MDS) and cluster and similarity analyses indicate the complex nature of the bleaching patterns and the influence of the strong 1997–1998 El Niño. A significant (global R-value?=?0.65; p < 0.01) compounding effect of the reef location and bleaching intensity on the differentiation of bleaching environments was detected. A combination of high SSTAc5day and low K 490 may cause coral bleaching in the northernmost reefs. Evidence clearly points to a scenario where the influence of reef location, bleaching year and intensity may produce a compounded effect that determines the bleaching environments in Bahia. 相似文献
996.
Kosuke Kato Masatoshi Sakawa 《Soft Computing - A Fusion of Foundations, Methodologies and Applications》2011,15(1):131-138
In this paper, we focus on multiobjective linear programming problems involving random variable coefficients in objective functions and constraints. Using the concept of chance constrained conditions, such multiobjective stochastic linear programming problems are transformed into deterministic ones based on the variance minimization model under expectation constraints. After introducing fuzzy goals to reflect the ambiguity of the decision maker??s judgements for objective functions, we propose an interactive fuzzy satisficing method to derive a satisficing solution for them as a fusion of the stochastic programming and the fuzzy one. The application of the proposed method to an illustrative numerical example shows its usefulness. 相似文献
997.
Radical polymerization of methyl methacrylate (MMA) in the presence of methyl -(bromomethyl) acrylate yielded poly-(MMA) bearing the 2-methoxycarbonylallyl end group through chain reaction involving bimol ecular termination. The molecular weight of the resultant polymer was effectively controlled with a small amount of the bromomethylacrylate added; the chain transfer constant was estimated to be 0.9. The poly (MMA) with the unsaturated end group (
相似文献
998.
999.
Hideki Katagiri Kosuke Kato Takashi Hasuike 《Expert systems with applications》2012,39(12):10639-10646
This paper considers a minimum spanning tree problem under the situation where costs for constructing edges in a network include both fuzziness and randomness. In particular, this article focuses on the case that the edge costs are expressed by random fuzzy variables. A new decision making model based on a possibility measure and a value at risk measure is proposed in order to find a solution which fully reflects random and fuzzy information. It is shown that an optimal solution of the proposed model is obtained by a polynomial-time algorithm. 相似文献
1000.
Tomoki Nakayoshi Koichi Kato Shuichi Fukuyoshi Ohgi Takahashi Eiji Kurimoto Akifumi Oda 《International journal of molecular sciences》2021,22(2)
Aspartic acid (Asp) residues are prone to nonenzymatic isomerization via a succinimide (Suc) intermediate. The formation of isomerized Asp residues is considered to be associated with various age-related diseases, such as cataracts and Alzheimer’s disease. In the present paper, we describe the reaction pathway of Suc residue formation from Asp residues catalyzed by two water molecules using the B3LYP/6-31+G(d,p) level of theory. Single-point energies were calculated using the MP2/6-311+G(d,p) level of theory. For these calculations, we used a model compound in which an Asp residue was capped with acetyl and methylamino groups on the N- and C-termini, respectively. In the aqueous phase, Suc residue formation from an Asp residue was roughly divided into three steps, namely, iminolization, cyclization, and dehydration, with the activation energy estimated to be 109 kJ mol−1. Some optimized geometries and reaction modes in the aqueous phase were observed that differed from those in the gas phase. 相似文献
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