我国B2C电子商务支付方式及信用风险分析

个人支付是开展B2C电子商务的必备条件，是制约中国B2C电子商务发展的瓶颈之一。本文介绍了目前国内的支付体系和B2C电子商务支付方式，从交易的信用风险角度分析了我国B2C电子商务支付现状的成因，并提出了初步对策。     

基于混合K-中心点的Web客户聚类

通过对Web日志文件进行分析，该文提出了一种改进的K-中心点聚类算法对Wweb用户的行为进行分析的方法。该算法利用模糊相似度，并模仿遗传算法中计算适应度思想，另加了一层循环迭代，每次比较适应度，保留最佳适应度，使之有较好的性能，改进了其易局部最优化的缺点。     

Market microstructure in a global B2B network

On‐line marketplaces raise several interesting issues, among them the relevance of location when content is digitized, and the assessment of a supplier's capabilities when buyers worldwide only have electronic contact with sellers. In global B2B on‐line marketplaces, market microstructures, i.e. which firms compete for the same customers, are thus likely to be influenced by how customers value location and firm capabilities in their decisions to do business with different suppliers on‐line. We suggest that both these sets of attributes will continue to matter on‐line—firms possessing similar capabilities, as well as firms that are similar in location by country, time zones or clusters, will compete for business from the same customers. We model the similarity in competitive positions between pairs of firms based on the overlap in their customer networks, using data on actual interactions between supplier and customer banks on an electronic trading system. Using QAP network regression techniques on the 100 largest banks in this industry, we find that similarity in capabilities influences who competes with whom, and that location still matters in a global B2B exchange. Interestingly, location influences who a firm's competitors are, but not where its customers are from. Copyright © 2001 John Wiley & Sons, Ltd.     

Time Series Concepts for Conditional Distributions*

The paper asks the question – as time series analysis moves from consideration of conditional mean values and variances to unconditional distributions, do some of the familiar concepts devised for the first two moments continue to be helpful in the more general area? Most seem to generalize fairly easy, such as the concepts of breaks, seasonality, trends and regime switching. Forecasting is more difficult, as forecasts become distributions, as do forecast errors. Persistence can be defined and also common factors by using the idea of a copula. Aggregation is more difficult but causality and controllability can be defined. The study of the time series of quantiles becomes more relevant.     

Regulation And The Rise In Asset-Based Mutual Fund Management Fees

In this article I explain why asset‐based fees are common for mutual fund management companies and why the average fee has increased recently. I argue that Securities and Exchange Commission fee regulations make alternative fee types illegal or unattractive. Management companies can maintain higher fees because regulations and brand‐name capital partly insulate them from competition and because investors cannot easily distinguish between performance‐oriented and marketing‐oriented fund companies. Index funds and unit investment trusts may offer competition to mutual funds in the future because they are designed to minimize management fees.     

氟硅酸泵的国产化实践

硅氟酸极具腐蚀性 ,考虑到经济性 ,2 0 #合金、哈氏合金、蒙乃尔等贵金属很少被选为泵材。由于橡胶、塑料等高分子材料具有很好的抗蚀性和一定的机械性能 ,且价格便宜 ,因此一般选用其作为泵体材料。我们通过分析、比较 ,成功选择国产氟硅酸泵替代国外进口泵 ,实现国产化。     

预防液化石油气储罐应力腐蚀的初探

液化石油气储罐在工业和人民生活中有着广泛的应用,探讨液化石油气中所含H2S腐蚀介质对储罐的应力腐蚀及预防措施显得非常重要。     

Auditor conservatism and voluntary disclosure: Evidence from the Year 2000 systems issue

This study further examines the phenomenon of conservative auditor behaviour by considering the level of voluntary disclosure of Year 2000 remediation information in company annual reports. Previous studies have provided evidence of conservative auditor behaviour by examining the link between Big 6 auditor choice and accruals (Francis and Krishnan 1999; Becker et al ., 1998; Defond and Subramanyam 1998). Protecting their reputation capital increases Big 6 auditor incentives to act conservatively to avoid litigation risk. We propose and find that Big 6 auditor clients disclose more Year 2000 remediation information than non–Big 6 auditor clients.     

Static and dynamic efficiency of pollution control strategies

A great deal of the economic literature on pollution control strategies concentrates on the efficiency of environmental policy instruments. Most analytical studies in this field show that market instruments are more efficient with respect to the cost of pollution abatement of a given number of polluters than non-market instruments. According to several analytical studies, market instruments should also be more efficient with respect to innovation in pollution abatement equipment than non-market instruments. In the empirical literature a great number of case studies exist with estimations of the savings of abatement costs of market instruments in a situation without technological progress. Empirical studies about the impact of environmental policy market instruments on the abatement costs in situations with technological progress are lacking.The purpose of this paper is to fill this gap. The paper deals with an empirical estimation of abatement costs for the emission of SO₂ of coal-fired electricity units in the Netherlands from 1985 to 2000. First, the working of market instruments and non-market instruments (the existing environmental policy of the Dutch government) is simulated in a static situation. Second, we analyse the learning effects of flue gas desulphurization. The efficiency advantage of market instruments turns out to be larger in a situation of technological progress than in a static situation.     

Web数据挖掘技术探索与应用

Web数据挖掘是当今世界上的热门研究领域,本文从Web数据挖掘的定义开始分析研究Web数据挖掘的难点、过程等相关技术,并计论其在电子商务领域中的相关应用。