某类高阶偏微分系统离散谱的估计

考虑某类高阶偏微分系统离散谱的估计,利用谱理论、矩阵运算、分部积分、测试函数、Ray—leigh定理和不等式估计等方法,获得了用前n个谱来估计第n＋1个谱的上界的不等式,且其估计系数与区域的几何度量无关,其结论是文献[4—5]的进一步推广．     

协同通信系统中差分调制在Rayleigh衰落信道中的误码性能分析

根据源-中继-目的节点链路的等效信噪比模型,推导了检测传送和选择检测传送两种 协议下目的节点瞬时信噪比的概率密度函数和特征函数,基于此推导了协同DMPSK调制近似 误符号率的闭合表达式。推导结果不含积分表达式,方便计算,为系统设计和功率分配提供 了理论基础。最后通过仿真验证了推导结果的正确性。     

International borrowing without commitment and informational lags: Choice under uncertainty

A series of recent studies in economic growth theory have considered a class of models of international borrowing where, in the absence of a perfect investment commitment, the borrowing constraint depends on the historical performances of the country. Thus, a better level of past economic activity gives a higher reputation, thereby increasing the possibility of accessing the international credit market. This note considers this problem in a stochastic setting based on the volatility of the internal net capital. We study how the optimal consumption level and the maximal expected welfare depend on the combined influence of the trajectory of past economic variables and the volatile environment. In particular, we show how the strength of the history effect and the relative weight of the historical performance depend on the degree of risk.     

The adaptive approach for storage assignment by mining data of warehouse management system for distribution centres

Among distribution centre operations, order picking has been reported to be the most labour-intensive activity. Sophisticated storage assignment policies adopted to reduce the travel distance of order picking have been explored in the literature. Unfortunately, previous research has been devoted to locating entire products from scratch. Instead, this study intends to propose an adaptive approach, a Data Mining-based Storage Assignment approach (DMSA), to find the optimal storage assignment for newly delivered products that need to be put away when there is vacant shelf space in a distribution centre. In the DMSA, a new association index (AIX) is developed to evaluate the fitness between the put away products and the unassigned storage locations by applying association rule mining. With AIX, the storage location assignment problem (SLAP) can be formulated and solved as a binary integer programming. To evaluate the performance of DMSA, a real-world order database of a distribution centre is obtained and used to compare the results from DMSA with a random assignment approach. It turns out that DMSA outperforms random assignment as the number of put away products and the proportion of put away products with high turnover rates increase.     

基于投影寻踪方法的粮食主产区农民用水合作组织绩效研究——基于湖北、湖南、黑龙江3省的调查

[目的]农民用水合作组织是我国灌溉管理制度改革的产物,农民用水合作组织的建立改进了农村水利管理的方式,提高了灌溉管理过程中水资源的利用率。[方法]通过构建粮食主产区农民用水合作组织绩效评价指标体系,建立基于实数编码加速遗传算法的投影寻踪分类模型,对湖北、湖南、黑龙江等3省61家农民用水合作组织的绩效进行了实证分析。[结果]粮食主产区农民用水合作组织绩效水平总体较好,在所调查的61家农民用水合作组织中,27.1%的农民用水合作组织绩效为优秀,28.8%绩效良好,13.6%绩效一般,30.5%绩效较差。[结论]总体上来看,湖南、湖北等2省农民用水合作组织的绩效高于黑龙江。是否有产权、农户参与率、是否民主决策、培训次数、农户满意度、单位面积灌水量和水费收取率等指标对农民用水合作组织绩效影响最大。因此,政府适当放权,选取恰当的扶持方式,提升农户的认识,推广好的农民用水合作组织发展模式是提高农民用水合作组织绩效的有效途径。     

The equilibrium exchange rates of European currencies and the transition to euro

This study estimates the demand system using Japanese micro data and calculates the cost of living index (COLI) to assess the substitution bias in the Consumer Price Index. The estimated bias during the sample period of 1982–2000 is about 0.06 percentage points, which is larger than the estimates calculated from a superlative index. The difference between the COLI and a superlative index can be explained with the upward movements of the average utility level in Japan, since the cost of living for the rich has grown more rapidly than that for the poor.     

Self-targeted food subsidies and voice: Evidence from the Philippines

This paper studies the targeting outcomes of a self-targeted rice subsidy program in the Philippines. We find modest within-community targeting outcomes, but weak between-community targeting. This appears to be because, controlling for the direct influence of household characteristics, participation was lower in poorer communities. These inter-community differentials are strongly correlated with several proxies for citizen “voice”, including education, income, and access to other public services. This suggests that self-targeting outcomes are not simply a function of the good selected for subsidy, but are also influenced by variations in communities’ access to usable services; that these variations favor richer communities; and that efforts to enhance consumer voice in disenfranchised communities would facilitate targeting improvements.     

一类具有无界时滞的微分不等式

本文建立了一类具有无界时滞微分不等式,将有界时滞微分不等式推广到无界时滞微分不等式,并得到其解的指数估计和渐近估计.     

文化差异视角下的英汉颜色词的联想

不同的民族由于地理、民俗、宗教及价值观念等方面的差异,在表达同一概念时,词汇被赋予了许多的联想意义。掌握汉英颜色词不同的文化联想意蕴,并且了解产生这些不同联想意义的原因不仅有利于提高英语学习水平,还能促进和加强中西文化之间的交流。     

中国经济思想史学会第十三届年会综述

本文介绍了中国经济思想史学会第十三届年会的主要议题,时与会代表围绕会议主题所提交论文的学术观点以及所进行的学术讨论进行了概括性和综合性的介绍与总结.