基于DSP的DVB流发射/接收系统

研究了数字视频广播流的发射／接收系统，基于DSP技术实现了0～8Mbps的DVB流的发射和接收系统，误码率低于10^-7，详细介绍了发射／接收系统数据处理原理，探讨了相关系统硬件设计和软件实现问题。     

国家将采取政策鼓励企业开拓农村消费市场

国务院在日前下发的《国务院关于促进流通业发展的若干意见》中指出，为加大农村市场建设力度，完善农村流通基础设施，国家将采取政策，鼓励有条件的企业开拓农村市场。     

基于加速度传感器的智能识别在电视上的应用与开发

随着iPod、iPhone、SonyPS3,以及智能电视等游戏和娱乐类系列消费类产品的成功和热销,加速度传感器作为动作操控和UI操作的接收装置所带来的全新的使用体验,越来越被广大消费所追捧。本文介绍了基于美新公司的MXC6202加速度传感器的原理、应用电路及软件开发流程。     

智能天线和空间分集接收技术

智能天线和空间分集接收技术是主要的两种空间信号处理技术。本文从传播路径的无线传输特性、空时信道模型以及不同环境的多径特性出发，分析了CDMA系统存在的主要问题以及智能天线和空间分集接收技术的工作原理，着重比较了这两种技术的区别以及应用场合。     

差分GPS数字信标接收机的研制

研究了一种可用于提高GPS定位精度的差分GPS(DGPS)数字信标接收机的设计和研制技术。简要介绍了DGPS的基本原理和GPS-DGPS的系统功能，分析了有源全向DGPS接收天线的设计原理，着重介绍了数字化DGPS接收单元的硬件和软件设计过程。     

虚拟式直接序列扩频通信电台的研究

文中提出的虚拟式直接序列扩频通信电台将直接序列扩频通信、软件无线电和虚拟技术相结合。使用虚拟技术，系统具有易于实现、开发快捷、性能改进灵活、容易与其它应用结合、有利于新标准的推广等优点。文中论述了虚拟式直接序列扩频通信电台原理，包括发射方、接收方的结构和多址通信的原理，并详细讨论了电台实现硬件和软件情况，最后进行了计算机模拟仿真，结果令人满意。     

遥感卫星接收控制软件分析与改进技术

简述了某遥感卫星地面接收站接收站接收控制系统组成和工作原理，介绍了软件系统结构的分析方法，提出了适应需求的改进方案，归纳了在改进过程中应注意的关键技术及解决措施。     

信道化接收机中微波放大技术的研究

介绍了信道化接收机实现的方案和工作原理，并对其接收系统中重要部件——宽频带放大器做了重点介绍，针对低噪声和宽频带2个主要指标，采用平衡式放大器进行设计，最后给出了仿真结果。     

多路毫米波接收信号相关合成技术

提出了多站小口径接收系统相关合成接收的方法。介绍了相关运算原理,并用于 毫米波多路接收信号的相关合成。针对大型天线不能机动、造价高的不利因素,提出了小型 化、机动化解决方案。采用三路相关合成技术,改善信噪比47 dB,相当于将天线口 径 减小42%。该方法适用于更多路的相关合成,对接收站的设计有一定参考意义 。     

引力波定位和通信技术

本文提出了利用引力波对飞行器和其它运动目标进行识别、跟踪和定化的理论.同时讨论了引力波通信原理和可能的技术方案.引力波通信的发射和接收,放大器原理在文末作了介绍.     

三网融合发展现状探讨

IP技术的发展使得三网融合成了不可回避的问题,融合已经成了现在网络发展的大趋势。介绍了三网融合的基本概念,以及现阶段我国并存的3种网络即电信网、有线电视网和互联网的一些基本现状和特点及其存在的问题,探讨了三网融合的技术基础,并简要介绍了几种网络融合业务和国外三网融合发展情况。     

A Conditional Role-Involved Purpose-Based Access Control Model

This paper presents a conditional role-involved purpose-based access control (CPAC) model, where users dynamically activate conditional roles in accordance with the context attributes. Based on conditional role, access permissions are assigned that represent what can be accessed for what purpose to roles under certain conditions. On the other hand, conditional purpose is applied along with allowed purpose and prohibited purpose in the model. It allows users using some data for certain purpose with conditions (for instance, Tony agrees that his income information can be used for marketing purposes by removing his name). The structure of a CPAC model is defined and investigated. Access purpose is verified in a dynamic behavior, based on user attributes, context attributes, and authorization policies. Intended purposes are dynamically associated with the requested data object during the access decision. An algorithm is developed to achieve the compliance computation between access purposes and intended purposes and is illustrated with role-based access control (RBAC). Access purpose authorization and authentication in the model are studied with the hierarchical purpose structure. The model separates authorization of access purpose from access decision that improves the flexibility of private data control.     

The right tree for the right bird: Location choice decision of Taiwanese firms’ FDI in China and Vietnam

Firms have to invest in foreign markets to maintain their competitive advantage, but a popular location for foreign direct investment (FDI) may not be suitable for everyone. Available literature as to location choice is mainly based on developed countries and large multinational enterprises (MNEs). However, this study investigates the location choice behaviour of firms originating in newly industrialized economies (Taiwanese firms) investing in emerging countries (China and Vietnam). According to the national economic development of China (further divided into South China and East China) and Vietnam, we divide the location into more developed and less developed regions. Through an empirical firm-level data collection and conditional logit analysis, this study found that: (1) firms with stronger ownership advantages prefer to invest in more developed than less developed regions; (2) firms occupying favourable positions in their network prefer to invest in more developed than less developed regions; (3) firms with a high degree of networking prefer to invest in less developed than more developed regions; (4) firms choose to invest in more developed than less developed regions to gain access to a large market; and (5) firms with strong resource-seeking motives prefer to invest in more developed than less developed regions to access their resources.     

一种简易的局域网拨号接入服务配置与网络资源共享方案

本文介绍一种简易的局域网拨号接入服务配置与网络资源共享方案。该方案是在局域网内以Windows98为系统平台的PC上实现的，使工作人员可在家中或其他有电话线的地方方便地通过实验室的局域网连接到校园网乃至互联网并使用其中的资源，从而可以有效的缓解目前普遍存在的拨号上网困难的问题。     

GPRS与UMTS系统网络接入安全机制的比较与研究

详细介绍了GPRS与UMTS系统的网络接入安全机制，分析了GPRS系统中存在的安全漏洞及UMTS较GPRS在网络接入安全性方面的改善，最后分析了UMTS系统中存在的安全缺陷。     

光纤无线融合网络(FiWi)能效改善综述

光纤无线宽带接入网架构(Fiber Wireless Broadband Access Network,FiWi)能随时随地为终端用户提供高质量的宽带接入服务。然而，由于大量智能设备的互联和指数级数据业务的增长，FiWi接入网也面临着高能耗的潜在挑战。针对融合FiWi接入网中无线反复重传、业务共存转发以及跨域资源整合所引发的高能耗问题，从高效频带分配、协作计算卸载以及网络虚拟化等方面介绍了国内外研究现状并进行了展望，以期在满足服务质量约束时进一步降低FiWi接入网中的能耗。     

网络信息安全服务分析与研究

本文就网络信息安全问题进行分析和研究。从计算机网络的概念、发展阶段、分类和组成等方面对计算机网络加以概述，并从网络信息安全的定义、网络信息安全问题的产生与网络信息安全的威胁对网络信息安全进行分析。为达到网络系统的信息安全，从机密性服务、完整性服务、可用性服务、数字签名、公钥基础设施和访问控制展开分析研究。     

基于VC的网络数据库快速访问方法

网络数据库的快速访问对于网络服务应用很重要。本文分析比较了基于VC开发网络数据库访问的几种方法,在此基础上阐述了如何在VC 6. 0开发环境下采用ADO(ActiveXDataObject)技术开发网络数据库快速访问应用程序,并进行了实验,给出了实验结果。     

The Two Sides of the Story: Network Investments and New Venture Creation

It is widely recognized that networks provide access to resources necessary for founding a new venture. However, they also come along with opportunity costs of time. We therefore argue that maintaining a set of network relationships is an investment that may not always pay off. More specifically, we develop detailed hypotheses on why the relationship between investing time in developing and maintaining a larger network and more intense network relationships and success in new venture creation may be best described by an inverted U. Testing our hypotheses on longitudinal data of 137 nascent entrepreneurs, we find broad support for our propositions.     

CATV系统前端载噪比的计算方法

本文针对CATV前端系统设计中载噪比的计算，给出了适用于各种信号条件下的载噪比计算公式。