政府采购的资源配置效应分析

作为市场经济国家公共支出管理重要手段之一的政府采购，随着各国政府职能履行范围和作用方式的不断变化和全球化效应的进一步加深，对一国国内经济乃至世界经济的影响日益显示出其威力。本文将分两种情况：封闭条件和开放条件；两种模式：分散采购和集中采购；两个部门：公共部门和私人部门采探讨政府采购对资源配置的影响，从经济学的角度分析如何通过政府采购来提高政府资源配置的效率。     

Optimal distributed resource allocation in a wireless sensor network for control systems

INTRODUCTION With the rapid development of wireless com-munication technology, the combination of wireless communication and control systems becomes a new trend of networked control systems. Among the kinds of wireless technologies, wireless sensor network (WSN) has attracted a lot of interest and visibility due to its huge application space. WSN is a kind of wire-less ad-hoc network which connects embedded sen-sors, actuators, and processors and in which each node consists of a wireles…     

基于分布式技术的数据备份与恢复

针对商务网络的普及应用和信息系统存储量越来越大的情况下的数据安全可靠性,在简单介绍构建系统的有关关键技术后,提出通过建立备份信息索引表和对数据进行水平分片来实现数据的备份和恢复,并给出了数据备份过程的部分代码,为大数据量信息系统设计提供了一种解决方法。     

一种基于.NET集散系统的串行通信实现

介绍以89C52单片机为下位机,PC机为上位机,通过由89C52单片机构成的通信控制器相连的集散系统(DCS)串行通信方案;研究在.NET中如何进行串行通信的编程技术,即如何利用.NET的平台调用技术实现在CLR中的托管代码调用非托管的Win32API串行通信DLL,并结合多线程、事件处理、同步访问技术来实现串行通信编程,还结合实例探讨单片机的串行通信编程技术。     

PipeCF： a DHT-based Collaborative Filtering recommendation system

Collaborative Filtering (CF) technique has proved to be one of the most successful techniques in recommendation systems in recent years. However, traditional centralized CF system has suffered from its limited scalability as calculation complexity increases rapidly both in time and space when the record in the user database increases. Peer-to-peer (P2P) network has attracted much attention because of its advantage of scalability as an alternative architecture for CF systems. In this paper, authors propose a decentralized CF algorithm, called PipeCF, based on distributed hash table (DHT) method which is the most popular P2P routing algorithm because of its efficiency, scalability, and robustness. Authors also propose two novel approaches: significance refinement (SR) and unanimous amplification (UA), to improve the scalability and prediction accuracy of DHT-based CF algorithm. The experimental data show that our DHT-based CF system has better prediction accuracy, efficiency and scalability than traditiona     

p2pDating: Real life inspired semantic overlay networks for Web search

We consider a network of autonomous peers forming a logically global but physically distributed search engine, where every peer has its own local collection generated by independently crawling the Web. A challenging task in such systems is to efficiently route user queries to peers that can deliver high quality results and be able to rank these returned results, thus satisfying the users’ information need. However, the problem inherent with this scenario is selecting a few promising peers out of an a priori unlimited number of peers. In recent research a rather strict notion of semantic overlay networks has been established. In most approaches, peers are connected to other peers based on a rigid semantic profile by clustering them based on their contents. In contrast, our strategy follows the spirit of peer autonomy and creates semantic overlay networks based on the notion of “peer-to-peer dating”. Peers are free to decide which connections they create and which they want to avoid based on various usefulness estimators. The proposed techniques can be easily integrated into existing systems as they require only small additional bandwidth consumption as most messages can be piggybacked onto established communication. We show how we can greatly benefit from these additional semantic relations during query routing in search engines, such as Minerva, and in the JXP algorithm, which computes the PageRank authority measure in a completely decentralized manner.     

基于分布式能源项目科技创新研究分析

分布式能源项目是我国“十三五”期间重点推进产业,预计到2020年我国分布式能源项目装机将达到1500万千瓦。本文以某医院分布式能源站项目为例,探讨分布式能源项目系统设计的重难点问题,创新性的提出相应的解决方案。本次研究工作采用逐时负荷系数法对医院冷热电负荷进行了合理预测；采用燃气内燃机、余热利用设备、调峰设备相结合的装机方案,既满足了用户的负荷需求,又避免了原动机装机过大的通病；从需求侧出发合理估算项目能耗及能效指标,避免了从供应端计算能耗指标需设置较多负荷调整系数的问题。     

浅淡分布式异构数据库访问技术

随着计算机网络技术和数据库技术的迅猛发展,分布式异构数据库系统在不改变原来局部数据库的基础上,为用户提供一个统一的、集成的多数据库环境,使用户能以统一的模式访问这些数据库。     

分布式虚拟现实在远程教学中的应用

分布式虚拟远程学习是对传统教学的一个重大突破,本文简要介绍了分布式虚拟现实(DVR),探讨了如何在分布式虚拟环境中利用虚拟现实建模语言VRML及其JAVA设计与实现远程教学的思想和方法。     

e-Learning情感计算模型设计研究

目前,绝大多数e-Learning系统是在传统智力观指导下设计开发而成,严重忽视了学习者情感智能的发展。脑科学研究表明,情感在注意、记忆、推理和决策等方面发挥重要作用。以情感计算学说、人工心理学、脑科学等相关理论为指导,赋予计算机和网络以情感智能,以设计出支持适应性学习的e-Learning情感计算模型。