基于PCI总线的DMA高速数据传输系统

提出了基于PCI总线接口技术实现DMA数据传输系统的通用设计方法。该方法应用于雷达接收机综合测试仪,当雷达接收机工作时,采用DMA方式的数据传输速率可以稳定地达到70MB/s,能够有效地采集并保存雷达各种参数,供主机快速进行雷达故障分析与判断。还重点介绍了数据传输系统中基于PCI总线的接口电路设计及基于WDM的PCIDMA驱动程序的开发。     

用于1553总线控制器的存储管理单元设计

从消息队列的数据存储结构定义、存储空间规划和控制过程设计三方面讨论了MIL-STD-1553/1773总线控制器的设计实现。在总线控制器的模块化设计方案中,这三个方面构成了总线控制器的核心模块棗存储管理单元,应用该方案可实现具有多消息自动处理功能的总线控制器。     

Generalized Laplacian approximations in Bayesian inference

This paper presents a new Laplacian approximation to the posterior density of η = g(θ). It has a simpler analytical form than that described by Leonard et al. (1989). The approximation derived by Leonard et al. requires a conditional information matrix R_η to be positive definite for every fixed η. However, in many cases, not all R_η are positive definite. In such cases, the computations of their approximations fail, since the approximation cannot be normalized. However, the new approximation may be modified so that the corresponding conditional information matrix can be made positive definite for every fixed η. In addition, a Bayesian procedure for contingency-table model checking is provided. An example of cross-classification between the educational level of a wife and fertility-planning status of couples is used for explanation. Various Laplacian approximations are computed and compared in this example and in an example of public school expenditures in the context of Bayesian analysis of the multiparameter Fisher-Behrens problem.     

机械装置转子支承系统临界转速估算K3法

根据机械振动和积木式传递矩阵法的原理,提出了用于估算单、双转子系统一阶临界转速的实用方法,从而得到的“K3表”可方便地使用于产品的方案设计阶段或现场排故,并可得到满意的工程精度。     

存储区域网络iSCSI协议的通信机制研究

介绍了存储区域网络主要采用的组网协议,包括FC协议、FCIP协议、iFCP协议和iSCSI协议,着重研究了一种利用TCP/IPI网组建存储区域网络的协议-iSCSI协议,分析了iSCSI协议的通信机制,比较了在IP网络上实现iSCSI协议通信的3种方法,开发了一种iSCSI协议数据单元与TCP数据帧间的接口算法及其硬件设计,并用 VHDL语言成功进行了行为级的仿真。     

试论高校体育乒乓球教学中学习动机的培养

学习动机是学生学习的基本动力因素之一。该文通过对教学目标设置、创设激起内驱力的情境和积极进行反馈等方面进行分析 ,论述了高校体育乒乓球教学中培养学生良好的学习动机 ,对提高教学质量将起到积极的推动作用。     

论我国企业编制"增值表"的现实必要性

增值表确能提供相当有用的财务信息 ,它丰富了企业对外报表的内容 ,借鉴国外有关社会责任会计的理论和方法 ,编制有中国特色的增值表 ,不仅必要 ,而且势在必行     

中国服务业显性比较优势测算——基于前向联系增加值出口

基于"前向联系增加值出口"方法,测算了1995-2011年中国服务业细分产业层面及按要素密集度特征分类层面的显性比较优势指数(RCA_F),并同基于"总出口"1的比较优势指数(RCA)进行了比较。研究发现,中国在全球价值链分工中,比较优势集中在资本密集型服务业领域,且实现了比较劣势向比较优势的转变;劳动、知识密集型服务业及健康教育公共服务均尚未取得比较优势,但是有迹象表明三个领域的比较劣势有改善的趋势。与基于前向联系增加值出口核算结果相比,基于总出口核算结果"高估"了劳动密集型产业的比较优势,其中对建筑业和零售贸易两个部门的估计偏差最大;同时,在资本、知识密集型两个领域存在不同程度的"低估"现象。     

A simple algorithm for calculating values for folded normal distribution

Folded normal distribution originates from the modulus of normal distribution. In the present article, we have formulated the cumulative distribution function (cdf) of a folded normal distribution in terms of standard normal cdf and the parameters of the mother normal distribution. Although cdf values of folded normal distribution were earlier tabulated in the literature, we have shown that those values are valid for very particular situations. We have also provided a simple approach to obtain values of the parameters of the mother normal distribution from those of the folded normal distribution. These results find ample application in practice, for example, in obtaining the so-called upper and lower α-points of folded normal distribution, which, in turn, is useful in testing of the hypothesis relating to folded normal distribution and in designing process capability control chart of some process capability indices. A thorough study has been made to compare the performance of the newly developed theory to the existing ones. Some simulated as well as real-life examples have been discussed to supplement the theory developed in this article. Codes (generated by R software) for the theory developed in this article are also presented for the ease of application.     

Testing for Serial Independence: Beyond the Portmanteau Approach

Portmanteau tests are typically used to test serial independence even if, by construction, they are generally powerful only in presence of pairwise dependence between lagged variables. In this article, we present a simple statistic defining a new serial independence test, which is able to detect more general forms of dependence. In particular, differently from the Portmanteau tests, the resulting test is powerful also under a dependent process characterized by pairwise independence. A diagram, based on p-values from the proposed test, is introduced to investigate serial dependence. Finally, the effectiveness of the proposal is evaluated in a simulation study and with an application on financial data. Both show that the new test, used in synergy with the existing ones, helps in the identification of the true data-generating process. Supplementary materials for this article are available online.