A NOTE ON EVANESCENT PROCESSES

This note examines the connection between μ-invariant measures for the transition function of a continuous-time Markov chain and those of its q-matrix, Q. The major result establishes a necessary and aufficient condition for a convergent μ-invariant measure for Q to be μ-inhant for the minimal transition function, P, under the assumption that P is honest. This corrects Theorem 6 of Vere-Jones (1969) and the first part of Corollary 1 of Pollett (1986), both of which assert that the above conclusion holds in the absence of this condition. The error was pointed out by E.A. van Doom (1991) and the counterexample which be presented provides the basis for the present arguments. In determining where the error occurred in the original proof, we are able to identify a simple sufficient condition for μ-invariance.     

网络防火墙技术应用分析

介绍了防火墙的概念、组成原理及几种典型的防火墙系统,对如何加强防火墙的防护作用进行了分析。     

基于主动网的SYN攻击防御

针对目前传统网防御TCP同步泛滥攻击的服务器主机、路由器过滤、防火墙方法的局限性,利用主动网的动态特性,提出一种基于主动网的同步泛滥防御机制,并通过仿真实验将它与传统网环境下的防火墙防御进行了性能比较和分析,结果表明主动网技术为同步泛滥攻击提供了良好的防御性能。     

IP Filter包过滤防火墙在校园网上的实现

介绍了利用IP Filter包过滤功能在网络出口组成防火墙实现网络安全,并通过一个校园网作为实例,说明包过滤规则的制定和在IP Filter上的配置。     

Countering Overseas Power in Global Value Chains: Information Asymmetries and Subcontracting in the Plastics Industry

Resource Dependency Theory (RDT) and Global Value Chain (GVC) analysis have been deployed in the strategic and international management literatures to address questions of power in dyadic relationships and global production networks, respectively. This paper integrates the two theoretical approaches in order to expand RDT, using insights from Hirschman's exit/voice model to show the options available to some firms but not others. Using the relationship between buyers and contract manufacturers from GVC analysis, we find a correlation between firm size and choice of strategic action in response to contract manufacturers' dependence on buyers. Large firms follow an acquiescence strategy while small manufacturers follow an avoidance strategy, able to use both exit and voice strategies. Enabled by scale or control over information, both of these approaches successfully reduce uncertainty and provide a source of sustained competitive advantage. Using a study of the production chain in consumer plastics manufacturing in China, we show how dependent firms respond to GVC induced pressure. We find that based on the size of the contract manufacturer, the range of strategic responses to power is constrained by the nature of the dependency in global value chains. This opens important insights into the role that structural characteristics of organizations (like size) play in determining strategic freedom.     

Supply Chain Consequences of Subsidies for Corporate Social Responsibility

The use of government incentives tied to market prices as means of boosting corporate social responsibility (CSR) has expanded notably in recent decades. Enhanced business tax deductions for charitable donations and credits for conservation easements are notable cases. While providing incentives for socially desirable behavior to achieve legislative goals has intuitive appeal, the broader economic consequences are not always fully understood. In this study, we examine such wider consequences for supply chains when subsidies for CSR are offered. One effect we identify is that since incentives are typically tied to market value, firms have not only an added incentive to achieve societal objectives (say by donating inventory) but also an incentive to raise output (retail) market prices. A second consequence is that since firms forgo potential revenues by engaging in socially desired behavior, they become increasingly sensitive to supplier pricing; in an uncoordinated supply chain this leads to input (wholesale) price concessions. Among other things, the results underscore that incentives put in place to meet broader societal objectives also have notable ramifications for suppliers, retailers, and consumers in primary markets.     

Repurposing Materials and Waste through Online Exchanges: Overcoming the Last Hurdle

Online material and waste exchanges (OMWEs) provide online channels to repurpose by‐products, unused materials and waste from industrial and commercial facilities. Unfortunately, OMWE's also have challenges. First, sellers may have access to other disposal options and, as a result, may not fully commit to the exchange. Second, buyers can face high uncertainty about the product exchanged and the transaction being undertaken. Overcoming these challenges is the “last hurdle” to making OMWEs successful. This study investigates the factors that reduce the buyers' uncertainty and increase the sellers' commitment to the OMWE. We analyze novel transaction‐level data from an online exchange (MNExchange.org) combined with other archival public records on county‐level repurposing and disposal statistics. First, we find that regional repurposing policies and alternatives have a complementary effect on sellers' commitment toward OMWEs, resulting in increased OMWE exchanges. However, regional disposal policies and alternatives have a substitution effect on sellers' commitment, resulting in reduced exchange success. Further, greater product and transaction information reduce the buyer's uncertainty and increase exchange success. Finally, the analysis shows that users' (buyers and sellers) heavily rely on their prior experience with OMWEs. Specifically, higher familiarity between the buyer–seller pair and familiarity with the OMWE system leads to higher likelihood of exchange success. This study lays the foundation for understanding OMWEs and has important implications for developing policies and operations to increase online transactions of by‐products, materials and wastes.     

The k-factor GARMA Process with Infinite Variance Innovations

In this article, we develop the theory of k-factor Gegenbauer Autoregressive Moving Average (GARMA) process with infinite variance innovations which is a generalization of the stable seasonal fractional Autoregressive Integrated Moving Average (ARIMA) model introduced by Diongue et al. (2008 Diongue, A.K., Guégan, D. (2008). Estimation of k-Factor GIGARCH Process: A Monte Carlo Study. Communications in Statistics-Simulation and Computation 37:2037–2049.[Taylor &; Francis Online], [Web of Science ®] , [Google Scholar]). Stationarity and invertibility conditions of this new model are derived. Conditional Sum of Squares (CSS) and Markov Chains Monte Carlo (MCMC) Whittle methods are investigated for parameter estimation. Monte Carlo simulations are also used to evaluate the finite sample performance of these estimation techniques. Finally, the usefulness of the model is corroborated with the application to streamflow data for Senegal River at Bakel.     

一场声势浩大的新闻事件策划——浅析《金沙》的推广宣传策略

“新闻事件策划”这个命题自上世纪九十年代中期被提出以后,长期受到广泛争议和关注。在笔者的研究中,以一系列新闻事件策划的理论和实践研究成果为评判标准,主要关注成都市历时打造一年的文化名片“金沙”,以及作为媒体聚焦点的《金沙》音乐剧。在分析“金沙”成功的造势背后,揭示这条“金光闪闪”的文化产业链运作的新思路。     

Predatory purchasing practices in global apparel supply chains and the employment relations squeeze in the Indian garment export industry

While the literature has long acknowledged worker rights abuses in global apparel supply chains, less attention has been paid to the recent worsening of certain decent work deficits and its causes, which this article links to predatory purchasing practices arising from growing power asymmetries. These practices, illustrated here by the garment export industry in India, exert downward pressure on wages and incite non‐standard forms of employment and greater verbal and physical abuse as productivity demands rise. They can be addressed through pricing mechanisms that cover the cost of decent work, appropriate State regulation and worker involvement.