在动物饲料市场上大豆和菜粕互帮互为替代品，为了研究用大豆主力期货为菜粕现货套期保值的功能，本文运用确定套期保值比率的OLS、VAR和ECM三个模型和套期保值绩效的衡量指标，对上述二者的套期保值比率和绩效进行了实证研究。结果显示，大豆主力期货和菜粕现货周数据的最佳套期保值比率是0.1338，套期保值绩效为0.0832。在本文中，从模型上看，ECM模型的套期保值比率和绩效比OLS和VAR模型要高，但利用样本数据所得的结果是OLS模型的套期保值比率和绩效比VAR和ECM模型要高。不过随着中国期货市场的逐步成熟，用大豆主力期货为菜粕现货套期保值功能将得到更好发挥，在以这些产品为原材料的企业的采购中将发挥更重要作用。
Soybeans and rapeseed meal in animal feed market are substitutes for the help each other in order to study the main futures soybean, rapeseed meal spot hedging function, the paper use the OLS to determine the hedge ratio, VAR and ECM three models and of preserving and increasing performance metrics, the hedge ratio and performance of the above two empirical studies. The results show that the optimal hedge ratio for soybean the main futures and rapeseed spot, weekly data is 0.1338, the hedging performance of 0.0832. In this article, from the model point of view, the hedge ratio and performance of the ECM model than the OLS and VAR models to be high, but the use of sample data obtained result is that the hedge ratio and performance of the OLS model is higher than the VAR and the ECM model . But with the gradual maturity of the futures market, the main futures soybean rapeseed spot hedging would be better to play in the corporate purchasing these products as raw materials will play a more (2012-05-20, WORD, 31KB, 下载12次)
基于多层架构设计模式的社会保险管理信息系统实现方法的研究
多层架构通过对应用功能进行具体分析和抽象的划分，将应用模块转化为应用系统对象分布到各个客户和服务器中，使得系统系统的效率和扩展性在整体上得以最大化。网络的广泛应用，促使企业得应用程序从传统得客户/服务器的传统两层次架构，向基于面向对象思想的多层架构演进。近年来面向对象技术和分布式计算技术的高速发展，以及人们对软件复用的强烈需求，带来了基于构件的软件开发技术。构件技术解决了开发大型复杂应用系统的固有问题，并为多层架构应用提供理想的开发和部署平台。使用构件技术建立多层架构应用是管理信息系统的必然趋势。
本文分别讨论了使用Borland公司的分布式技术和基于面向对象思想的构件技术来实现基于多层架构模式的社会保险管理信息系统。并将设计模式技术应用在多层架构模式的设计中。
design based on multi-layered structure model of social insurance management information systems method of multi-layered structure through correspondence Function-specific analysis and abstract boundaries Application Module will be transformed into application systems targeted distribution to various clients and servers, In this system, the efficiency of the system and the scalability to maximize overall. The wider use of the network to promote enterprises in the application from a traditional client/server traditional two-level structure, Based on object-oriented to the ideological evolution of the multi-layered structure. In recent years, object-oriented technology and distributed computing technology's rapid development, and on software reuse of the strong demand, bring the compon (2007-03-13, WORD, 552KB, 下载46次)
嵌入式系统应用工程师借用计算机专家创建的C语言，使嵌入式系统应用得以飞速发展，而MISRAC是嵌入式系统应用工程师对C语言嵌入式应用做 出的贡献。如今MISRA C已经被越来越多的企业接受，成为用于嵌入式系统的C语言标准，特别是对安全性要求极高的嵌入式系统，软件应符合MISRA标准。
本文由清华嵌入式系统研究专家，邵贝贝教授领衔执笔，分六讲，跟读者一起学习MISRAC。
第一讲：“‘安全第一’的C语言编程规范”，简述MISRAC的概况。
第二讲：“跨越数据类型的重重陷阱”，介绍规范的数据定义和操作方式，重点在隐式数据类型转换中的问题。
第三讲：“指针、结构体、联合体的安全规范”，解析如何安全而高效地应用指针、结构体和联合体。
第四讲：“防范表达式的失控”，剖析MISRAC中关于表达式、函数声明和定义等的不良使用习惯，最大限度地减小各类潜在错误。
第五讲：“准确的程序流控制”，表述C语言中控制表达式和程序流控制的规范做法。
第六讲：“构建安全的编译环境”，讲解与编译器相关的规范编写方式，避免来自编译器的隐患。
希望大家喜欢。
embedded system engineers use computer experts created by the C language, Embedded systems make application to rapid development MISRAC which is embedded system engineers from the C language embedded application made contributions. Now MISRA C has been more and more enterprises are accepted as for embedded system in C language standard, especially for high security requirements of embedded systems, software should comply with MISRA standards. This paper from Qinghua embedded systems, an expert Professor Shao Beibei headed the pen, six speakers, with the readers learn MISRAC. 1st : " 'safety first' C programming language norms," MISRAC brief overview. 2nd : "data across numerous types of traps" to introduce a standardized data definitions and practices, focus on (2006-10-22, WORD, 59KB, 下载95次)