The social value of income information in a model with market power and endogenous variety

The present paper analyzes the value of public information in a general equilibrium economy with imperfect competition. The welfare effects of an improved information system for perfectly competitive economies have been extensively investigated in the published literature. Schlee (2001) shows that the value of information is always negative in exchange economies if an efficient risk sharing mechanism exists. In contrast, in economies with production, better information reduces welfare provided consumers are sufficiently risk-averse ( Eckwert and Zilcha 2000, 2003 ). In the present paper it will be shown that this result is robust if the production sector exhibits monopolistic competition in the Chamberlinian sense. Even so, the inefficiency of equilibria adds further potential for positive welfare effects of improved information. A model is presented where the degree of market imperfection is positively linked to the value of information. If the markup on competitive prices is sufficiently high, the value of information is positive; that is, better information increases economic welfare.     

中国农产品出口市场结构的实证分析及国际比较

使用了出口市场集中度指数等分析工具,对我国农产品出口市场结构进行实证分析.结果表明,与世界主要农产品出口国相比,我国农产品的出口市场结构比较集中,在1993～2006年期间经历了先恶化后改善的过程;与肉类产品和水产品相比,我国蔬菜水果产品的出口市场结构相对较为合理.     

TD-SCDMA系统中一种软件集成智能天线算法

给出了一种采用信干噪比准则的、集成了预多波束天线与LMS自适应天线的软件天线方案,该方案采用开关合并方法,把软件天线输出接到最大输出信噪比的算法输出,实现算法分集.在TD-SCDMA动态模型上对提出的方法进行了仿真,结果表明,采用集成软件天线方案的误码率性能要优于单纯的预多波束天线或LMS自适应智能天线.仿真过程考虑了用户来波方向和用户到基站距离的动态变化,以及功率控制算法和系统同步过程的影响.     

全球化与民族文化的多样性探析

全球化是一个历史范畴,是世界各国各地区的经济、政治、文化等领域超越国界、扩大联系的历史进程和历史趋势。全球化加速了强势文化的扩张和弱势文化的萎缩,各种文化在融合的过程中趋同,全球化不断吞噬文化多元性。因此从对全球化、文化、文化的多样性及民族文化的概念界定,探析全球化对民族文化的影响及冲击。     

Organizational diversity programs across cultures: effects on absenteeism,turnover, performance and innovation

This study examined data from over 5000 organizations in 22 countries to address three complementary issues: (1) the influence of national culture on the adoption of diversity programs aimed at recruiting, training and promoting individuals from specific target groups; (2) the moderating effect of national cultural practices on the relationship between these diversity programs and the organizational outcomes of absenteeism and turnover; and (3) the mediating effect of absenteeism and turnover on the relationship between diversity programs and organizational performance and innovation. National cultural values and practices were taken from the GLOBE study and assigned respectively to the organizations in our sample. A multilevel path analysis supported the hypothesized effects of national cultural values on organizational diversity programs. Moreover, cultural practices were found to moderate the relationship between diversity programs and absenteeism and turnover. Our hypotheses on the role of absenteeism and turnover as mediators of the relationship between diversity programs and organizational performance and innovation were also supported. Our findings may help guide managers' decisions on the adoption of diversity programs in units operating in different national cultures. We discuss the implications of our findings for scholars and practitioners concerned with diversity management issues in a global context.     

发射分集系统在空间相关莱斯快衰落信道下的性能

我国加入WTO以后,对于上海的发展是一个千栽难逢的机遇,同时也给上海的发展带来新的挑战。本文通过详实的资料分析了上海经济发展的现状和制约上海进一步发展的问题,并运用市场营销新理论,提出构建上海现代化大都市的营销战略。     

基于CP分解的MIMO-OFDM系统接收信号盲检测

多输入多输出-正交频分复用（MIMO-OFDM）无线通信系统中接收信号从空间、时间、频率的维度形成多因素的阵列信号,传统的矢量或者矩阵代数的建模方法在处理多因素信号问题上显得不足,无法利用多因素间的关系,而张量分析在解决多维阵列信号处理的问题上具有优势。针对MIMO无线通信系统,结合OFDM技术,研究了张量信号的建模及分解方法,并充分利用张量信号的分解唯一性提高无线接收信号的检测能力。提出了基于CP（CANDECOMP/PARAFAC）张量分解方法对未知信道状态（CSI）的MIMO-OFDM系统进行接收端的张量信号建模和盲检测,并通过仿真分析验证了模型的可行性。仿真结果表明,在接收天线数目大于发送天线数目且各径信道独立情况下,基于CP分解的接收信号盲检测算法在误码率为10-4时,随着接收天线数目增加,信噪比可获得约5 dB的增益。     

具有天线选择与中继选择的空间调制技术

针对空间调制（SM）技术存在的缺欠,提出了具有天线选择和中继选择的空间调制系统方案。首先在多输入多输出(MIMO)信道模型下,通过对发送端天线选择,将拥有最佳信道状态的天线选出进行SM,打破SM技术对发送端天线数的限制,并提升采用高阶调制的SM分集性能。然后进一步将此思想引入协作通信网络,结合传感器网络的分级观念,提出采用中继选择和空间调制的中继传输协议,并通过仿真观察系统分集性能的改善。仿真结果表明,上述中继传输协议不仅能提升系统性能,而且使系统配置更加灵活。     

Returns to alliance portfolio diversity: The relative effects of partner diversity on firm's innovative performance and productivity

This study considers the impact of diversification in types of technological alliances, resulting in alliance portfolio diversity, on various dimensions of a firm's performance, as they relate to exploration and exploitation. Using a large panel of innovative firms in the Netherlands, this study shows that partner type diversity in a firm's alliance portfolio has an inverted U-shaped relationship with productivity and radical innovative performance and a positive relationship with incremental innovative performance. Moreover, the results suggest that a lower level of diversity is needed to achieve an optimal level of productivity compared to radical innovative performance, whereas for incremental innovative performance a higher level of portfolio diversity appears to give the best performance.     

Where do international board members come from? Country-level antecedents of international board member selection in European boards

In this paper, it is argued that boards internationalize by recruiting international directors in order to increase companies’ performance. However, increasing nationality diversity on a board can be costly considering that it potentially creates cooperative problems on a board due to fault-lines and separation processes. As a result, boards will prefer international candidates who are more similar to themselves on a variety of ‘distances’. Based on data collected regarding 5683 board members of 361 companies from 15 countries in 2005–2007, we discover that the greater the distance (cultural, institutional and geographical) between the candidates’ and the companies’ country-of-origin, the lower the fraction of board members of that nationality on boards. Subsequently, it is argued that historical ties between countries play a ‘distance compressing’ role and partially compensate for the effects of distance. A colonial tie between countries will make recruitment of these particular nationalities more likely than others.