Abstract:The standard mean-variance portfolio selection model assumes that investors exactly know the seurity parameters，neglecting the effect of parameter uncertainty on portfolio selection．This paper investigates a continuous。time mean-variance portfolio selection problem under parameter uncertainty and Bayesian learning． The problem is solved by using a martingale approach，and the optimal investment strategy and the mean-variance efficient frontier are derived in closed form．Based on these results．we sive an empirical analysis with data from Chinese security markets．The analysis shows that parameter uncertainty has a great effect on the optimal investment strategy and the investment performance．

Abstract:This paper presents two further studies on the relationship between trade credit and bank borrowing. First，based on two kinds of classic option theories on corporate liability(Merton，1 974；Leland，1 994)，for the first time as far as we know，we theoretically derive two explicit formulas of elasticity of bank borrowing with respect to trade credit in the cases of default boundaries determined exogenously and endogenously respectively．Substitution between trade credit and bank borrowing and its counter-business-cycle behavior Can be characterized by analysis of those elasticity formulas．Second，using a sample containing totally 5354 lines of data selected from all companies listed in Shanghai and Shenzhen stock markets of China during 1998-2006， we estimate a time-varying coefficients panel model with fixed effects by controlling endogeneity which sires supportive evidences to the existence of substitution between trade credit and bank borrowing in China．More importantly，by Kappa consistency tests，we find the varying behavior of such substitution moves in a coincidently counter-business-cycle manner．This finding implies that firms in the tightening period had better choose a"to-send-charcoal-in-snowy-weather" strategy，and in the loose period，the bottom lines of trade credit policy should be strictly stuck to．

Abstract:Based on Kalman filter，this article use state space model to estimate time varying optimal hedge ratio of china's copper futures market and compare hedge performance of it with that of CC-GARCH model, VECM model，VAR model and OLS model．Hedging effectiveness is measured using the percentage of variance reduction and the percentage of sharp ratio reduction．We find that in terms of the two different measurement of hedging effectiveness，state space model based on Kalman filter perform significantly better than other models．The conclusion is robust to hedge periods．The results of the comparison of dynamic CC-GARCH model with static models depend on the duration of the hedge．VECM model perform worst and the hedging performance of VAR model does not significantly surpass that of simple OLS model．The risk of econometric models includes model·misspecification risk and estimation risk．Although the model-misspecification risk of advanced econometric model may be smaller than simple models，its estimation risk is greater and the total risk is uncertain．We find the solution of Kalman filter agrees with Bayesian rules，as suggestes Kalman filter approach outperform other models in dealing with estimation risk．

Abstract:Facilitator is very impoflant to electronic meetings. Due to the scarcity of qualified facilitator and elopment of automated facilitator becomes an attractive task．This study figures out the functions supporting electronic brainstorming for idea generation task，and tests those functions in the experiment setting．The user evaluations of those functions are valuable for the design of advanced automated facilitation in the future．Our experiment also shows that group members with automated facilitation support make more comments and produce more ideas than that without automated facilitation support．

Abstract:This paper proposes e-business value-creation to be a dynamic conversion process．From an e-business process point of view，we present a model of e-business value-creation process to examine the casual relationships among strategy，IT resources，e-business capabilities and process performance． Unlike former research that is from a structural and static view，this paper goes deep into casual links among factors at a e-business process level and explains the mediating role of e-business process in value creation．Based on the model，a series of hypotheses is developed．An empirical study of 177 manufacturers in China validates the proposed hypothesizes using structural equation modeling(SEM)．The results demonstrate a critical causal link from e-business strategy planning to integrative age of IT resources and consequently generating distinctive e-business capabilities and process performance．The characteristics of three-stage process in e-business value creation are summarized．This research also provides a new approach to exploring the e—business value creation．

Abstract:In order to better understand what mediating capabilities are needed to use B2 B technology to improve supply chain performance(SCP)and what relationships exist among these capabilities，grounded in the IT process-oriented view and the capability hierarchy view，this paper identified three different levels of mediating capabilities，i.e.，application capability of e-business(ACEB)，e-business systems capability(EBSC)，and e-business support capability for collaborative strategy(ESCS)，and then developed a theoretical model for addressing the impacts of ACEB on the EBSC and ESCS．A confirmatory factor analysis Writ8 performed to test this model by using 1 52 valid samples from Chinese manufacturing sectors．The results validate the multi-dimension constructs of the ACEB，and show that the ACEB have a direct effect on the EBSC，a direct and indirect effect on the ESCS，and a moderating effect on the relationship between the EBSC and the ESCS．

Abstract:Formal contracts and informal arrangements are always jointly used in business．The relationship between formal contract and informal contract is a new topic in contract theory．This paper builds a random matching game model to analyze the influence of formal contract on informal contract when formal contract is available，and therefore extend the research on interaction of informal contract and formal contract from two-sided repeated game to random matched game．The conclusion is that contracting cost affects contract choice and the interaction between formal contract and informal contract．When contracting cost is low，the introduction of formal contract substitutes informal contract；when contracting cost is medium，formal contract complements informal contract；when contract cost is high，the introduction of formal contract does not affect informal contract．Finally，the model is used to analyze the effect of the introduction of the third intermediaries on informal contract in online auction trade．

Abstract:During "Eleventh Five-Year"，the distribution of National Natural Science Foundation's founding on the macro-management and policy subject was increasingly clear，and we basically realized the "Eleventh Five-Year" development objectives of macro-management and policy subject．Under the circumstances that the subject background have changed greatly，the macro-management and policy subject have many opportunities and challenges，such as the inputs of NNSF are continuously increasing，subjects's distribution is more rational，priority funding areas are continued and deepened，the basic problems of subject system's building are concerned，and research results shall be more openness and visibility．

Abstract:Based on data from Natural Science Foundation of China，this paper，adopting the spatial statistics methods，investigates on the funding effects of fund for less developed regions．It is concluded that，against the disequilibrium spatial distribution of science fund projects，the fund for less developed regions can not only improve the capability of basic research from less developed regions，but also influence the spatial distribution of national basic research，relieving the over-concentration of the basic research resources．