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Transient Model for Shafting Vibration of Hydro Turbine Generating Sets 被引量:1
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作者 Zeng Yun Zhang Lixiang +2 位作者 Zhang Chengli Yu Fengrong Qian Jing 《仪器仪表学报》 EI CAS CSCD 北大核心 2013年第S1期190-196,共7页
The shafting vibration is closely related to the rotational angular speed.The angular speed of hydro turbine generating sets(HTGS)is rapidly change in fault transient,it maybe reduce the shafting damage.By means of en... The shafting vibration is closely related to the rotational angular speed.The angular speed of hydro turbine generating sets(HTGS)is rapidly change in fault transient,it maybe reduce the shafting damage.By means of energy analysis,the differential equation of shafting vibration for the HTGS is derived,in which include the equation of generator rotor and hydro turbine runner,it can be applied to transient analysis.Shafting model is transformed into first order differential equation groups,and is combined with the motion equation of HTGS to build integrated model.Various additional forces of shafting are taken as input inspire in proposed model,the generality of model is good.At last,the shafting vibration in emergency stop transient is simulated. 展开更多
关键词 hydro TURBINE generating setS SHAFTING VIBRATION transient model FAULT
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Generating Set of the Complete Semigroups of Binary Relations 被引量:1
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作者 Yasha Diasamidze Neset Aydin Ali Erdoğan 《Applied Mathematics》 2016年第1期98-107,共10页
Difficulties encountered in studying generators of semigroup of binary relations defined by a complete X -semilattice of unions D arise because of the fact that they are not regular as a rule, which makes their invest... Difficulties encountered in studying generators of semigroup of binary relations defined by a complete X -semilattice of unions D arise because of the fact that they are not regular as a rule, which makes their investigation problematic. In this work, for special D, it has been seen that the semigroup , which are defined by semilattice D, can be generated by the set . 展开更多
关键词 SEMIGROUPS Binary Relation generated set generators
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Nonlinear Dynamic Characteristic Analysis of the Shaft System in Water Turbine Generator Set 被引量:11
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作者 MA Zhenyue SONG Zhiqiang 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2009年第1期124-131,共8页
A 3D finite element vibration model of water turbine generator set is constructed considering the coupling with hydropower house foundation. The method of determining guide bearing dynamic characteristic coefficients ... A 3D finite element vibration model of water turbine generator set is constructed considering the coupling with hydropower house foundation. The method of determining guide bearing dynamic characteristic coefficients according to the swing of the shaft is proposed, which can be used for studying the self-vibration characteristic and stability of the water turbine generator set. The method fully considers the complex supporting boundary and loading conditions; especially the nonlinear variation of guide bearing dynamic characteristic coefficients and the coupling effect of the whole power-house foundation. The swing and critical rotating speed of an actual generator set shaft system are calculated. The simulated results of the generator set indicate that the coupling vibration model and calculation method presented in this paper are suitable for stability analysis of the water turbine generator set. 展开更多
关键词 water turbine generator set dynamic characteristic coefficients NONLINEARITY coupling vibration critical speed
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Dynamic weighted voting for multiple classifier fusion:a generalized rough set method 被引量:9
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作者 Sun Liang Han Chongzhao 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2006年第3期487-494,共8页
To improve the performance of multiple classifier system, a knowledge discovery based dynamic weighted voting (KD-DWV) is proposed based on knowledge discovery. In the method, all base classifiers may be allowed to ... To improve the performance of multiple classifier system, a knowledge discovery based dynamic weighted voting (KD-DWV) is proposed based on knowledge discovery. In the method, all base classifiers may be allowed to operate in different measurement/feature spaces to make the most of diverse classification information. The weights assigned to each output of a base classifier are estimated by the separability of training sample sets in relevant feature space. For this purpose, some decision tables (DTs) are established in terms of the diverse feature sets. And then the uncertainty measures of the separability are induced, in the form of mass functions in Dempster-Shafer theory (DST), from each DTs based on generalized rough set model. From the mass functions, all the weights are calculated by a modified heuristic fusion function and assigned dynamically to each classifier varying with its output. The comparison experiment is performed on the hyperspectral remote sensing images. And the experimental results show that the performance of the classification can be improved by using the proposed method compared with the plurality voting (PV). 展开更多
关键词 multiple classifier fusion dynamic weighted voting generalized rough set hyperspectral.
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The Structure and the Sufficent and Necessary Conditions for Generalized Statistically Self-Similar Sets 被引量:1
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作者 DENG Ai-jiao HU Di-he (College of Mathematics and Computer Science,Wuhan University,Wuhan 430072,China) 《Wuhan University Journal of Natural Sciences》 CAS 2000年第1期13-21,共9页
We constructed a class of generalized statistically self-similar set.S and give the necessary and sufficent conditions to ensure a random recursive set being a generalized statistically self-similar set. The statist... We constructed a class of generalized statistically self-similar set.S and give the necessary and sufficent conditions to ensure a random recursive set being a generalized statistically self-similar set. The statistically self-similar sets defined by Hutchinson,Falconer,Graf are the special cases of ours. 展开更多
关键词 statistically recursive set generalized statistically self-similar set Hausdorff metric
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Estimating the ultimate bound and positively invariant set for a generalized Lorenz system 被引量:1
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作者 舒永录 张永浩 《Journal of Chongqing University》 CAS 2008年第2期151-154,共4页
A generalized Lyapunov function was employed to investigate the ultimate bound and positively invariant set of a generalized Lorenz system.We derived an ellipsoidal estimate of the ultimate bound and positively invari... A generalized Lyapunov function was employed to investigate the ultimate bound and positively invariant set of a generalized Lorenz system.We derived an ellipsoidal estimate of the ultimate bound and positively invariant set for the generalized Lorenz system,for all the positive values of system parameters a,b,and c.Our results extend the related result of Li,et al.[Li DM,Lu JA,Wu XQ,et al.,Estimating the ultimate bound and positively invariant set for the Lorenz system and a unified chaotic system,Journal of Mathematical Analysis and Application,2006,323(2):844-653]. 展开更多
关键词 generalized Lorenz system ultimate bound positively invariant set generalized Lyapunov function
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α-Input and α-Unit Resolution Methods for Generalized Horn Clause Set in L_(V(n×2))F(X) 被引量:1
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作者 何星星 徐扬 +1 位作者 李莹芳 刘军 《Journal of Donghua University(English Edition)》 EI CAS 2012年第1期66-70,共5页
a-Input resolution and a-unit resolution for generalized Horn clause set are discussed in linguistic truth-valued lattice-valued first-order logic ( Lv( n × 2) F(X) ), which can represent and handle uncerta... a-Input resolution and a-unit resolution for generalized Horn clause set are discussed in linguistic truth-valued lattice-valued first-order logic ( Lv( n × 2) F(X) ), which can represent and handle uncertain linguistic values-based information. Firstly the concepts of a-input resolution and a.unit resolution are presented, and the equivalence of them is shown. Then α-input (a-unit) resolution is equivalently transformed from Lv( n × 2) F(X) into that of LnP(X), and their soundness and completeness are also established. Finally an algorithm for a-unit resolution is contrived in LnP( X). 展开更多
关键词 linguistic truth-valued lattice-valued logic a-input resolution α-unit resolution generalized Horn clause set
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Generalized dominance-based rough set approach to security evaluation with imprecise information 被引量:3
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作者 Zhao Liang Xue Zhi 《High Technology Letters》 EI CAS 2010年第3期254-262,共9页
The model of grey multi-attribute group decision-making (MAGDM) is studied, in which the attribute values are grey numbers. Based on the generalized dominance-based rough set approach (G-DR- SA), a synthetic secur... The model of grey multi-attribute group decision-making (MAGDM) is studied, in which the attribute values are grey numbers. Based on the generalized dominance-based rough set approach (G-DR- SA), a synthetic security evaluation method is presented. With-the grey MAGDM security evaluation model as its foundation, the extension of technique for order performance by similarity to ideal solution (TOPSIS) integrates the evaluation of each decision-maker (DM) into a group's consensus and obtains the expected evaluation results of information system. Via the quality of sorting (QoS) of G-DRSA, the inherent information hidden in data is uncovered, and the security attribute weight and DMs' weight are rationally obtained. Taking the computer networks in a certain university as objects, the example illustrates that this method can effectively remove the bottleneck of the grey MAGDM model and has practical significance in the synthetic security evaluation. 展开更多
关键词 security evaluation grey number multi-attribute group decision-making (MAGDM) generalized dominance-based rough set approach (G-DRSA)
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Category of Generalized Intuitionistic Fuzzy Sets 被引量:1
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作者 YANGWan-cai LIXiao-shen 《Chinese Quarterly Journal of Mathematics》 CSCD 北大核心 2005年第2期192-199,共8页
In this paper, category GIFS of generalized intuitionistic fuzzy sets(GIF) is built up. Topoi properties of category GIFS are studied. Firstly, it is proved that the category GIFS has all topoi properties except that ... In this paper, category GIFS of generalized intuitionistic fuzzy sets(GIF) is built up. Topoi properties of category GIFS are studied. Firstly, it is proved that the category GIFS has all topoi properties except that it has no subobject classifiers, Secondly, it is proved that the category GIFS has middle object and consequently GIFS is a weak topos. Thirdly, by the use of theory of weak topos GIFS, the power object of an object in GIFS is studied. 展开更多
关键词 CATEGORY TOPOS middle object weak topos generalized intuitionistic fuzzy set
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Benson proper efficiency for vector optimization of generalized subconvexlike set-valued maps in ordered linear spaces 被引量:2
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作者 周志昂 《Journal of Shanghai University(English Edition)》 CAS 2010年第5期374-379,共6页
Several equivalent statements of generalized subconvexlike set-valued map are established in ordered linear spaces. Using vector closure, we introduce Benson proper efficient solution of vector optimization problem. U... Several equivalent statements of generalized subconvexlike set-valued map are established in ordered linear spaces. Using vector closure, we introduce Benson proper efficient solution of vector optimization problem. Under the assumption of generalized subconvexlikeness, scalarization, multiplier and saddle point theorems are obtained in the sense of Benson proper efficiency. 展开更多
关键词 set-valued maps vector closure generalized subconvexlikeness Benson proper efficient solution
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Lagrange-Maxwell equation and magnetic saturation parametric resonance of generator set
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作者 杨志安 李文兰 +1 位作者 邱家俊 席晓燕 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2007年第11期1545-1553,共9页
Lagrange-Maxwell's equation is extended firstly. With the theory of electromechanical analytical dynamics, the magnetic complement energy in air gap of generator is acquired. The torsional vibration differential equa... Lagrange-Maxwell's equation is extended firstly. With the theory of electromechanical analytical dynamics, the magnetic complement energy in air gap of generator is acquired. The torsional vibration differential equations with periodic coefficients of rotor shafting of generator which is in the state of.magnetic saturation are established. It is shown that the magnetic saturation may cause double frequency electromagnetic moment. By means of the averaging method, the first approximate solution and corresponding solution of the primary parametric resonance is obtained. The characteristics and laws of the primary parametric resonance excited by the electromagnetism are analyzed and some of new phenomena are revealed. 展开更多
关键词 generator set magnetic saturation the averaging method primary parametric resonance
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Some Polar Sets for the Generalized Brownian Sheet
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作者 LI Huiqiong LIU Luqin CHEN Zhenlong 《Wuhan University Journal of Natural Sciences》 CAS 2008年第2期137-140,共4页
Let W^-(t)(t∈R+^N) be the d-dimensional N-parameter generalized Brownian sheet. We study the polar sets for W^-(t). It is proved that for any α∈ R^d, P{W^-(t) = α, for some t∈ R〉^N} = {1, if βd 〈 2N ... Let W^-(t)(t∈R+^N) be the d-dimensional N-parameter generalized Brownian sheet. We study the polar sets for W^-(t). It is proved that for any α∈ R^d, P{W^-(t) = α, for some t∈ R〉^N} = {1, if βd 〈 2N ,0 if αd〉 2N and the probability that W^-(t) has k-multiple points is 1 or 0 according as whether 2kN〉d(k-1)β or 2kN 〈 d(k - 1)α. These results contain and extend the results of the Brownian sheet, where R〉^N = (0,+∞)U,R+^N = [0,+∞)^N,0〈 α ≤1and β〉1. 展开更多
关键词 generalized Brownian sheet polar set single point multiple points
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Mathematical Model and Geometrical Model of Double Pitch ZN-type Worm Gear Set Based on Generation Mechanism 被引量:2
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作者 SHU Linsen CAO Huajun +2 位作者 LI Xianchong ZHANG Chenglong LI Yuxia 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2015年第3期549-555,共7页
The current researches on the tooth surface mathematical equations and the theory of gearing mainly pay attention to the ordinary type worm gear set(e.g., ZN, ZA, or ZK). The research of forming mechanism and three-... The current researches on the tooth surface mathematical equations and the theory of gearing mainly pay attention to the ordinary type worm gear set(e.g., ZN, ZA, or ZK). The research of forming mechanism and three-dimensional modeling method for the double pitch worm gear set is not enough. So there are some difficulties in mathematical model deducing and geometry modeling of double pitch ZN-type worm gear set based on generation mechanism. In order to establish the mathematical model and the precise geometric model of double pitch ZN-type worm gear set, the structural characteristics and generation mechanism of the double pitch ZN-type worm gear set are investigated. Mathematical model of the ZN-type worm gear set is derived based on its generation mechanism and the theory of gearing. According to the mathematical model of the worm gear set which has been developed, a geometry modeling method of the double pitch ZN-type worm and worm gear is presented. Furthermore, a geometrical precision calculate method is proposed to evaluate the geometrical quality of the double pitch worm gear set. As a result, the maximum error is less than 6′10–4 mm in magnitude, thus the model of the double pitch ZN-type worm gear set is available to meet the requirements of finite element analysis and engineering application. The derived mathematical model and the proposed geometrical modeling method are helpful to guiding the design, manufacture and contact analysis of the worm gear set. 展开更多
关键词 double pitch ZN-type worm gear set generation mechanism mathematical model geometrical model
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Upper and Lower Semicontinuity of Solution Sets for Parametric Generalized Vector Quasi-equilibrium Problems
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作者 LI AI-QIN FAN LI-YA 《Communications in Mathematical Research》 CSCD 2011年第1期1-5,共5页
In this paper, two kinds of parametric generalized vector quasi-equilibrium problems are introduced and the relations between them are studied. The upper and lower semicontinuity of their solution sets to parameters a... In this paper, two kinds of parametric generalized vector quasi-equilibrium problems are introduced and the relations between them are studied. The upper and lower semicontinuity of their solution sets to parameters are investigated. 展开更多
关键词 parametric generalized vector quasi-equilibrium problem solution set upper semicontinuity lower semicontinuity set-valued mapping
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A NOTE ON GENERALIZED MORAN SET
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作者 李文侠 肖冬梅 《Acta Mathematica Scientia》 SCIE CSCD 1998年第S1期88-93,共6页
Let E be a generallied Moran set. The authors determine the dim E and get the sufficient and necessary condition for E being a s-set.
关键词 generalized Moran set Box dimension s-set
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Federated Learning Model for Auto Insurance Rate Setting Based on Tweedie Distribution 被引量:1
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作者 Tao Yin Changgen Peng +2 位作者 Weijie Tan Dequan Xu Hanlin Tang 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第1期827-843,共17页
In the assessment of car insurance claims,the claim rate for car insurance presents a highly skewed probability distribution,which is typically modeled using Tweedie distribution.The traditional approach to obtaining ... In the assessment of car insurance claims,the claim rate for car insurance presents a highly skewed probability distribution,which is typically modeled using Tweedie distribution.The traditional approach to obtaining the Tweedie regression model involves training on a centralized dataset,when the data is provided by multiple parties,training a privacy-preserving Tweedie regression model without exchanging raw data becomes a challenge.To address this issue,this study introduces a novel vertical federated learning-based Tweedie regression algorithm for multi-party auto insurance rate setting in data silos.The algorithm can keep sensitive data locally and uses privacy-preserving techniques to achieve intersection operations between the two parties holding the data.After determining which entities are shared,the participants train the model locally using the shared entity data to obtain the local generalized linear model intermediate parameters.The homomorphic encryption algorithms are introduced to interact with and update the model intermediate parameters to collaboratively complete the joint training of the car insurance rate-setting model.Performance tests on two publicly available datasets show that the proposed federated Tweedie regression algorithm can effectively generate Tweedie regression models that leverage the value of data fromboth partieswithout exchanging data.The assessment results of the scheme approach those of the Tweedie regressionmodel learned fromcentralized data,and outperformthe Tweedie regressionmodel learned independently by a single party. 展开更多
关键词 Rate setting Tweedie distribution generalized linear models federated learning homomorphic encryption
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A New Kind of Generalized Pythagorean Fuzzy Soft Set and Its Application in Decision-Making
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作者 Xiaoyan Wang Ahmed Mostafa Khalil 《Computer Modeling in Engineering & Sciences》 SCIE EI 2023年第9期2861-2871,共11页
The aim of this paper is to introduce the concept of a generalized Pythagorean fuzzy soft set(GPFSS),which is a combination of the generalized fuzzy soft sets and Pythagorean fuzzy sets.Several of important operations... The aim of this paper is to introduce the concept of a generalized Pythagorean fuzzy soft set(GPFSS),which is a combination of the generalized fuzzy soft sets and Pythagorean fuzzy sets.Several of important operations of GPFSS including complement,restricted union,and extended intersection are discussed.The basic properties of GPFSS are presented.Further,an algorithm of GPFSSs is given to solve the fuzzy soft decision-making.Finally,a comparative analysis between the GPFSS approach and some existing approaches is provided to show their reliability over them. 展开更多
关键词 Pythagorean fuzzy set generalized Pythagorean fuzzy soft set ALGORITHM decision making
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Research and Development of Engine-Generator Set Control System for Tracked Vehicle Electric Transmission System 被引量:1
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作者 黄英 黄千 +2 位作者 孙逢春 刘波澜 刘嘉 《Defence Technology(防务技术)》 SCIE EI CAS 2007年第3期179-184,共6页
As an energy generating equipment, the engine-generator set supplies power to the electric transmission. Therefore, its control is one of the key technologies of electric vehicles. Based on the discussion about the de... As an energy generating equipment, the engine-generator set supplies power to the electric transmission. Therefore, its control is one of the key technologies of electric vehicles. Based on the discussion about the demands to the engine-generator set in tracked vehicles, the detailed function of engine-generator and the control strategy are determined. The hardware and software of the control system are also developed and tested in a prototype vehicle. The experiment results show that the control system has good reliability and can satisfy the power requirements of vehicles under all operating conditions. 展开更多
关键词 自动控制技术 电力传输 汽车发动机 控制理论
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DNA Sequences with Forbidden Words and the Generalized Cantor Set
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作者 Zhuowei Yang Ping Wang 《Journal of Applied Mathematics and Physics》 2019年第8期1687-1696,共10页
In this work, we establish relations between DNA sequences with missing subsequences (the forbidden words) and the generalized Cantor sets. Various examples associated with some generalized Cantor sets, including Hao... In this work, we establish relations between DNA sequences with missing subsequences (the forbidden words) and the generalized Cantor sets. Various examples associated with some generalized Cantor sets, including Hao’s frame representation and the generalized Sierpinski Set, along with their fractal graphs, are also presented in this work. 展开更多
关键词 DNA SEQUENCES generALIZED CANTOR set
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MULTI-GRAY EDGE DETECTION BASED ON GENERALIZED FUZZY SET
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作者 Wang Hui (Institute of Information Engineering, Shenzhen University, Shenzhen 518060) 《Journal of Electronics(China)》 2002年第4期426-430,共5页
In this letter, drawbacks of the classical algorithm to enhance the fuzzy contrast among adjacent regions are analyzed. Based on it, a new fuzzy enhancement algorithm and a linear fuzzy distribution that maps the gray... In this letter, drawbacks of the classical algorithm to enhance the fuzzy contrast among adjacent regions are analyzed. Based on it, a new fuzzy enhancement algorithm and a linear fuzzy distribution that maps the gray images to corresponding generalized fuzzy set are proposed. Results of two examples illustrate that the algorithm is more effective and faster when used to detect the multi-level edges of images. 展开更多
关键词 Fuzzy enhancement generalized fuzzy set Edge detection
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