基于802.11i的无线局域网安全加密技术研究

为了提高无线局域网的安全性,解决传统安全机制WEP协议中所存在的缺陷,给出了一种基于IEEE802.11i的无线局域网安全模型.在分析了IEEE802.11i协议的体系结构和安全机制的基础上,对IEEE802.11i的数据加密技术进行了剖析,详细分析了TKIP和CCMP协议的加解密过程和安全性能,结果表明,TKIP的安全性能仍有局限性,只是一种过渡方案,而CCMP才是健壮的数据保密协议.     

Direct dry film optical bonding ‐ A low‐cost,robust, and scalable display lamination technology

Abstract— A robust, repeatable, low‐cost lamination process that utilizes pressure‐sensitive adhesive (PSA) to directly bond substrates to displays, such as LC, OLED, plasma, and electrophoretic displays, has been developed. These substrates can vary in intent and serve as protective covers, reflection mitigation, heaters, filters, touch screens, environmental barriers, etc. The resultant assembly is very rugged (shock, impact, and vibration resistant), while maximizing optical performance. This paper briefly describes the traditional liquid bonding technologies and compares them to dry‐film bonding. A section of the paper focuses on the enhanced optical and environmental performances of dry‐film bonded displays. This paper may also serve as a brief review of optical‐bonding technologies.     

军用软件检验方法研究

计算机技术在军用信息化的发展与应用,使武器装备系统中软件成分的比例越来越高、规模越来越大,极大地提高了武器装备的许多原有性能,发挥了最大潜能,获得了崭新的能力。军用软件的质量已经成为检验军工产品的重要指标。长期以来,在使用和实践中暴露出的软件与软件有关的问题逐渐增多,直接影响了整个武器系统的质量,为避免和消除错误,就要加强军用软件检验方法研究,来不断提高武器装备软件的质量与可靠性。     

A new compact dual‐wideband printed monopole antenna for WLAN/WiMAX applications

A new compact printed monopole antenna with dual‐wideband characteristics is presented for simultaneously satisfying wireless local area network and worldwide interoperability for microwave access applications. The antenna structure consists of a circular monopole with a microstrip feed‐line for excitation and a hexagon conductor‐backed parasitic plane. The antenna has a small size of 13 mm × 26 mm × 1 mm. © 2011 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2011.     

物联网及其军事应用

介绍了物联网的内涵、发展及用途,并以图的形式形象地比较了物联网与其他网络的关系。以美军为例,阐述了物联网给军事应用所带来的变革,即实现战场感知的实时化、精确化,武器装备智能化、网络化,综合保障灵敏化、可视化,网络战由虚拟步入现实。同时,简要介绍了美军正在开发的两个物联网军事应用系统,最后提出了对我军应用物联网技术的建议。     

基于PCF的无线局域网接入时延可控系统研究

目前无线局域网(WLAN)中使用最广的是IEEE 802.11协议,该协议定义了两种信道访问机制:分布式协调功能(DCF)和点协调功能(PCF).其中,DCF采用基于竞争的信道访问机制,因此,多个连有传感器的站点采集数据在信道中传输就会出现碰撞和时延不可控的问题;而PCF采用轮询的方式来提供一种非竞争的访问机制,很好地解决时延不可控制的问题.针对这种情况,提出采用集中控制协议完成PCF访问机制,协议中定义超帧结构并将超帧划分为多个时隙,以此实现无竞争的信道访问机制.实验结果表明:整个网络中传感器采集数据最大接入时延控制在90 ms以内.     

对WAPI证书鉴别的安全性分析与改进

WAPI是国内第一个的无线局域网标准。该文对WAPI中的证书鉴别过程进行了安全性分析,并对其中的安全缺陷提出了改进方案．使协议达到预期的安全目标。     

无线网络在图书馆中的应用

介绍了无线网络的相关知识．详细阐述了无线网络在图书馆中的应用。     

无线局域网技术在校园网中应用

根据目前无线局域网在校园网中的现状,分析比较了无线局域网技术与有线网络之间的差异,总结了无线局域网技术的应用优势与缺陷,并给出了现阶段无线局域网技术在校园网中的实际应用前景。     

Triple‐band metamaterial‐inspired antenna using FDTD technique for WLAN/WiMAX applications

In this article, a triple‐band metamaterial (MTM)‐inspired antenna has been designed and analyzed using finite difference time domain technique (FDTD). The proposed MTM consists of two L‐dumbbell‐shaped unit cells, feed, and partial ground plane. The proposed antenna shows triple‐band characteristics with impedance bandwidths of 10.6, 4.67, and 26.8% centered at 2.4, 3, and 5.7 GHz, respectively. The first two bands are working at zeroth‐order resonating mode and first‐order resonating mode while third is due to series slot and coupling between feed and ground plane. It offers compact nature with total antenna size of 30 × 30 × 1.6 mm³. The proposed triple‐band antenna has been designed and analyzed using FDTD code based on convolutional perfectly matched layer boundary conditions and HFSS as well. The prototype antenna has also been fabricated and tested experimentally to validate the simulation results. The proposed antenna exhibits good radiation characteristics throughout the working bands. © 2015 Wiley Periodicals, Inc. Int J RF and Microwave CAE 25:688–695, 2015.