Changing composition of human capital The Czech Republic,Hungary and Poland1

We show that business education/occupations have expanded and that technical education/occupations have contracted in the Czech Republic and Poland since 1990. We interpret these changes as an adjustment necessary for their transition to a market economy. We do not find the same pattern in Hungary, which we attribute to the earlier timing of its transition. We construct an aggregate model in which labour reallocates in response to changing demand structure. When calibrated with the Czech and Polish data, the model generates a large movement of workers with technical education and experience into business occupations in the early 1990s. The discounted sum of output loss due to the gap between the demand structure and the composition of existing human capital amounts to between 8 and 40 percent of 1990 GDP.     

A note on the existence of unique equivalent martingale measures in a Markovian setting

Simple sufficient conditions for the existence of a unique equivalent martingale measure are provided. Furthermore, these conditions give us a handle on situations where an equivalent martingale measure cannot exist. The existence of a unique equivalent martingale measure is of relevance to problems in mathematical finance. Two examples of models for which the question of existence was unresolved are studied. By means of our results existence of a unique equivalent measure up to an explosion time is proved.     

基于延迟自相关特性的码速率测量技术

通信信号的识别与解调是通信侦察的重要研究内容，在通常情况下，通信信号的很多参数并不知道。本文介绍了一种基于通信信号码延迟自相关特性的码速率测量技术，并给出了码速率测量理论分析及基于硬件的实现技术，仿真和实验结果表明本方案具有较高的测量性能。     

Estimation of the mean in ranked set sampling with non responses

The estimation of the population mean when ranked set sampling [rss] is used for selecting the sample and non responses [nr] are present, is studied. The nr stratum is sub sampled using simple random sampling with replacement. Two strategies are analyzed. One of them is based on the selection of a sub sample from the nr in each cycle. The other uses sub samples selected among the nr in each rank.  The accuracy of the proposed estimators is characterized by the corresponding expected variances. Simulations and real life data are used for analyzing the behavior of them. Acknowledgements: This paper was developed partially during the visit of the author to Université des Antilles et Gouyane. The author gratefully acknowledges the helpful suggestions of the referees and thanks the support of DAAD for visiting Humboldt University where a version of the paper version was made.     

Forms of Foreign Investment Liberalization and Risk in Emerging Stock Markets

I examine the effect of different forms of foreign investment liberalization on risk in emerging equity markets, including international cross-listings and closed-end country funds, and in the domestic equity market as foreign investment restrictions are eliminated. I find that in Latin American markets volatility declines significantly with different forms of foreign investment liberalization, and in Asian markets volatility does not increase significantly. Volatility is driven by domestic factors in South America, but the transmission of volatility from the United States to Mexico increases after liberalization. The market risk exposure increases in Argentina after liberalization, in Chile with an index of American Depositary Receipts, and in Thailand with greater foreign ownership, reducing the diversification benefits of these markets.     

供应链构建的机制分析

介绍了供应链的概念，交易成本经济学的基本理论，并把二者结合从经济学的角度分析了供应链构建的经济学机理，为供应链理论的发展提供了一个新的研究方向。     

Efficient Liability Rules: Complete Characterization

Received May, 18, 2000; revised version received March, 19, 2001     

Equity‐Based Compensation for Employees: Firm Performance and Determinants

I examine the effect of employee equity‐based compensation (EBC) on firm performance and the determinants of EBC. Using two samples, I find that firms have come to rely more heavily on EBC than in the past. For both samples, I document a significant, positive relation between Tobin's q and the percentage of employee compensation that is equity based. For accounting returns, I find a positive relation with the earlier sample. However, for the later sample I find that greater use of EBC leads to lower levels of future accounting returns. I also find that the determinants of the proportion of EBC are different between the two samples.     

基于RFID的零售企业信息追溯与补库策略

提出了基于无线射频技术（RFID）的零售企业生鲜食品的信息追溯技术和持续补库计划（CRP）策略,集成了整合发货和库存补货,并构建了用以计算最高库存量和配送周期的供应商管理库存模式下的补货数学模型,模型中充分考虑了生鲜食品的特性（腐坏）,确保零售企业销售生鲜食品的质量安全.在通过采用RFID技术实时监控销售和库存数据的基础上,供应商能够依据模型在发货周期内确定最佳的货物配送时间和配送数量,主动补货,在保证食品安全的同时实现总的长期平均成本最小化.