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Minimal feasible sets in variable resource constrained projects

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Journal of Systems Engineering and Electronics 2009年第5期20卷 974-984页

作者： Cui Wanan~(1,2,3),Yue Chaoyuan~3,Chen Yingchun~4 & Cao Xiuning~5 1.Coll.of Management,Guangxi univ.for Nationalities,Nanning 530006,p.r.china 2.school of Economics and Management,wuhan univ.,wuhan 430072,p.r.china 3.Inst.of Systems Engineering,Huazhong univ.of science and Technology,wuhan 430074,p.r.china 4.Unit 91388 of the pLA,Zhanjiang 524022,p.r.china 5.school of Business,Hunan univ.of science and Technology,Xiangtan 411201,p.r.china Coll. of Management Guangxi Univ. for Nationalities Nanning 530006 P. R. China School of Economics and Management Wuhan Univ. Wuhan 430072 P. R. China Inst. of Systems Engineering Huazhong Univ. of Science and Technology Wuhan 430074 P. R. China Inst. of Systems Engineering Huazhong Univ. of Science and Technology Wuhan 430074 P. R. China Unit 91388 of the pLA Zhanjiang 524022 P. R. China school of Business Hunan Univ. of Science and Technology Xiangtan 411201 P. R. China

To determine the reasonable resource dependent relations between activities for the purpose of exactly computing the total floats and the free floats of activities, correctly identifying critical activities and critical sequences in a project schedule with variable resource constraints, the concept of the minimal feasible set （MFS） is proposed and the properties of MFS are discussed. The methods to identify optimal MFSs and resource links are then studied. Furthermore, MFS is generalized to the situation that the preconditions of MFS are not satisfied. Contrastive results show that in establishing resource links and resolving floats, MFS is at least not inferior to other methods in all cases and is superior in most situations.

关键词： project schedule resource constraint minimal feasible set resource dependent relation.

Evaluation Method of Web Site Structure Based on Web Structure Mining

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wuhan univ.rsity Journal of Natural sciences 2003年第3A期8卷 791-796页

作者： Li Jun\|e 1 , Zhou Dong\|ru 2 1. computer Center,wuhan univ.rsity, wuhan 430072, Hubei, china 2. school of computer,wuhan univ.rsity, wuhan 430072, Hubei,china wuhan univ.rsity Computer Center Wuhan Hubei China (GRID:grid.49470.3e) (ISNI:***) wuhan univ.rsity School of Computer Wuhan Hubei China (GRID:grid.49470.3e) (ISNI:***)

The structure of Web site became more complex than before. During the design period of a Web site, the lack of model and method results in improper Web structure, which depend on the designer's experience. From the point of view of software engineering, every period in the software life must be evaluated before starting the next period's work. It is very important and essential to search relevant methods for evaluating Web structure before the site is completed. In this work, after studying the related work about the Web structure mining and analyzing the major structure mining methods (page\|rank and Hub/Authority), a method based on the page\|rank for Web structure evaluation in design stage is proposed. A Web structure modeling language WSML is designed, and the implement strategies for evaluating system of the Web site structure are given out. Web structure mining has being used mainly in search engines before. It is the first time to employ the Web structure mining technology to evaluate a Web structure in the design period of a Web site. It contributes to the formalization of the design documents for Web site and the improving of software engineering for large scale Web site, and the evaluating system is a practical tool for Web site construction.

关键词： web structure mining page\|rank web structure evaluation modeling language for web structure

A prICE-SETTING NEWSVENDOr MODEL UNDEr CVAr DECISION CrITErION WITH EMErGENCY prOCUrEMENT

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Journal of Systems science and Systems Engineering 2010年第1期19卷 85-104页

作者： Minghui XU school of Economics and Management,wuhan univ.rsity,wuhan 430072,china school of Economics and Management Wuhan University Wuhan China

In this paper, we consider a newsvendor model in which a risk-averse manager faces a stochastic price-dependent demand in either an additive or a multiplicative form. An emergency purchase option is allowed after the realization of demand to satisfy the units that are short. By adopting Conditional value-at-risk （CVar） as the decision criterion, we aim to investigate the optimal pricing and ordering decisions, and the effects of parameter changes in such a setting. We provide sufficient conditions for the uniqueness of the optimal policy for both demand models. We perforl~, comparative statics analysis to show how the optimal pricing and ordering decision behaves when changing parameters. We also compare our results with those of the newsvendor with a general utility function and with CVar criterion under lost sales assumption. Our key results include：（i） For both demand models, the optimal selling price is decreasing in risk aversion. Hence, the optimal price of a risk-averse newsvendor is not greater than the optimal price of a risk-neutral newsvendor. （it） In contrary to the lost sales case, for the multiplicative demand model, the optimal order quantity may not be monotonic in risk aversion. Consequently, the optimal risk-averse order quantity may be lower or higher than the optimal risk- neutral counterpart. （iii） For the additive model, the optimal order quantity is strictly increasing in the emergency purchase price, while for the multiplicative model the optimal order quantity has no such a monotonic property. Some numerical examples are conducted to verify our claims and gain more insights about the risk-averse decision-making behaviors.

关键词： Newsvendor model inventory pricing risk aversion conditional value-at-risk

Hierarchical Classification of Chinese Documents Based on N grams

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wuhan univ.rsity Journal of Natural sciences 2001年第Z1期6卷 416-422页

作者： Zhou Shui geng 1, Guan Ji hong 2, He Yan xiang 2 1. State Key Laboratory of Software Engineering, wuhan univ.rsity, wuhan 430072, china 2. school of computer science, wuhan univ.rsity, wuhan 430072, china State Key Laboratory of Software Engineering Wuhan University Wuhan China school of computer science Wuhan University Wuhan China

We explore the techniques of utilizing N gram information to categorize Chinese text documents hierarchically so that the classifier can shake off the burden of large dictionaries and complex segmentation processing, and subsequently be domain and time independent. A hierarchical Chinese text classifier is implemented. Experimental results show that hierarchically classifying Chinese text documents based N grams can achieve satisfactory performance and outperforms the other traditional Chinese text classifiers.

关键词： Chinese text classification N grams feature selection hierarchical classification

Early Age Compressive Strength of pastes by Electrical resistivity Method and Maturity Method

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Journal of wuhan univ.rsity of Technology(Materials science) 2011年第5期26卷 983-989页

作者：肖莲珍 school of Materials science and Engineering Wuhan Institute of Technology

The compressive strength development of portland cement pastes was investigated by the electrical resistivity method and the maturity *** experiments were carried out on the cement pastes with different water-cement ratios at different curing *** results show that the application of the maturity method has limitation to obtain the *** is found that both of the compressive strength and the electrical resistivity follow hyperbolic trend for all the *** hyperbolic equation of each mix is obtained to estimate the ultimate resistivity value which can probably be *** relationship between electrical resistivity and compressive strength of the cement pastes is established based on the test results and interpreted by the empirical Archie equation and a strength-porosity *** relationship between the electrical resistivity after temperature correction and the compressive strength was linear and independent of curing temperature and water-cement ratio.

关键词： electrical resistivity cement hydration compressive strength maturity method

DOUBLE Φ-FUNCTION INEQUALITY FOr NONNEGATIVE SUBMArTINGALES

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Chinese Annals of Mathematics,Series B 2000年第2期21卷 211-216页

作者： MEI TAO(College of Mathematics and computer sciences, wuhan univ.rsity, wuhan 430072, china.) LIU pEIDE(College of Mathematics and computer sciences, wuhan univ.rsity, wuhan 430072, china.) College of Mathematics and computer sciences Wuhan University Wuhan 430072 China

The authors establish a kind of inequalities for nonnegative submartingales which depend on two functions　ψ and ψ, and obtain the equivalent conditions for　Φ and ψ such that this kind of inequalities holds. In t... 详细信息

关键词： Matingale Nonnegative submartingale Maximal function Φ-function inequality

Drift Analysis in Studying the Convergence and Hitting Times of Evolutionary Algorithms: An Overview

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wuhan univ.rsity Journal of Natural sciences 2003年第S1期8卷 143-154页

作者： He Jun, Yao Xin1.State Laboratory of Software Engineering, wuhan univ.rsity, wuhan 430072, Hubei,china 2.school of computer science, univ.rsity of Birmingham, Birmingham B15 2TT, England wuhan univ.rsity State Laboratory of Software Engineering Wuhan Hubei China (GRID:grid.49470.3e) (ISNI:***) univ.rsity of Birmingham School of Computer Science Birmingham England (GRID:grid.6572.6) (ISNI:***)

This paper introduces drift analysis approach in studying the convergence and hitting times of evolutionary algorithms. First the methodology of drift analysis is introduced, which links evolutionary algorithms with Markov chains or supermartingales. Then the drift conditions which guarantee the convergence of evolutionary algorithms are described. And next the drift conditions which are used to estimate the hitting times of evolutionary algorithms are presented. Finally an example is given to show how to analyse hitting times of EAs by drift analysis approach.

关键词： evolutionary algorithms convergence hitting time drift analysis

A Constraction of General Solution for a Class of Non-Homogeneous recurrence of Variable Coefficients with Two Indices

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wuhan univ.rsity Journal of Natural sciences 2000年第4期5卷 379-385页

作者： Yu Chang-an College of Mathematics and computer science, wuhan univ.rsity, wuhan 430072,china wuhan univ.rsity College of Mathematics and Computer Science Wuhan China (GRID:grid.49470.3e) (ISNI:***)

In this paper, we obtain an explicit formula of general solution for a class of the non-homogeneous recurrence of variable coefficients with two indices.

关键词： two indices variable coefficients non homogeneous recurrence explicit solution

An efficient method for detecting concurrency errors in object-oriented programs

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science china(Information sciences) 2012年第12期55卷 2774-2784页

作者： HE YanXiang 1,2,WU Wei 2 & CHEN Yong 2 1 school of computers,wuhan univ.rsity,wuhan 430072,china 2 State Key Laboratory of Software Engineering,wuhan univ.rsity,wuhan 430072,china 1. school of computers Wuhan University Wuhan 430072 China2. State Key Laboratory of Software Engineering Wuhan University Wuhan 430072 China

Multicore and multi-threaded processors have become the norm for modern ***,concurrent programs have become more and more prevalent despite being difficult to write and *** errors are highly likely to appear in concurrent code,conventional error detection methods such as model checking,theorem proving,and code analysis do not scale smoothly to concurrent *** is an indispensable technique for detecting concurrency errors,but it involves a great deal of manual work and is *** paper presents an automatic method for detecting concurrency errors in classes in object-oriented *** method uses a heuristic algorithm to automatically generate test cases that can effectively trigger ***,each test case is executed automatically and a fast method is adopted to identify the actual concurrency error from anomalous run *** have implemented a prototype of the method and applied it to some typical Java *** shows that our method is more effective and faster than previous work.

关键词： concurrency error dynamic test data race atomicity violations test case generation