A robust and efficient dynamic identity‐based multi‐server authentication scheme using smart cards

In single‐server architecture, one service is maintained by one server. If a user wants to employ multiple services from different servers, he/she needs to register with these servers and to memorize numerous pairs of identities and passwords corresponding to each server. In order to improve user convenience, many authentication schemes have been provided for multi‐server environment with the property of single registration. In 2013, Li et al. provided an efficient multi‐server authentication scheme, which they contended that it could resist several attacks. Nevertheless, we find that their scheme is sensitive to the forgery attack and has a design flaw. This paper presents a more secure dynamic identity‐based multi‐server authentication scheme in order to solve the problem in the scheme by Li et al. Analyses show that the proposed scheme can preclude several attacks and support the revocation of anonymity to handle the malicious behavior of a legal user. Furthermore, our proposed scheme has a lower computation and communication costs, which make it is more suitable for practical applications. Copyright © 2014 John Wiley & Sons, Ltd.     

数字节目虚拟现实交互系统的实现与应用

技术革新推动着经济、文化、思维方式、生活方式等各个领域的革新.在中国的电视领域,技术也同样会带来革新效应,在直播、转播、节目制作、电视包装等诸多领域,技术一直在不断地推陈出新,其中,现实与虚拟的结合一直是一个持续性的课题.实现数字技术的跨界、融合与应用,就如同将不同的元素放在一起不断实验,得到的成果却往往为传统产业打开一扇未来之门.本文以"幻维数码"在国内率先开发、研制、推广应用的"魔幻演播系统"为例,剖析在当下中国的演播环境中,虚拟现实技术的融合与应用将对中国电视演播产生的革新影响力.     

基于LabVIEW的发酵尾气监控系统设计

为了能够实时的获取、分析发酵过程中呼吸商的变化情况,设计了发酵过程的尾气监控系统。该系统以LabVIEW为主要开发平台,并辅以Matlab和MySQL数据库,以实现对微生物发酵过程尾气数据的在线检测、存储,以及实时调节呼吸商（RQ）。系统采用Fuzzy-PID控制算法稳定调控RQ值在0.82,其静态误差仅在±0.02,并通过实验对比说明Fuzzy-PID控制优于常规PID控制。     

DMZ内视场光学分割型航摄相机子影像高准确度几何拼接

针对内视场光学分割型相机,利用子影像同名像点虚拟影像坐标相等这一约束条件,提出一种高准确度子影像几何拼接方法.首先在分析各CCD几何安置误差的基础上,设计拼接关系并给出拼接参量计算方法;其次结合SIFT等高准确度影像匹配算子对拼接模型进行优化选择,给出子影像拼接流程;最后采用附加参量自检校技术进行畸变参量再精化处理.利用所提方法对一款自行设计的数字大面阵复合相机进行几何拼接试验,结果表明该方法能够有效解决高准确度子影像几何拼接、高量测性能大幅面虚拟影像生成问题,拼接后影像内符准确度可达子像元级,满足航测作业对数字航摄相机测图准确度和摄影效率的应用要求.     

Design and development of an automotive magnetorheological semi-active differential

This paper describes a research activity concerning the design and the development of an automotive semi-active differential based on the use of a magnetorheological fluid that allows to control the locking torque and, consequently, to improve the vehicle handling. Starting from a gearbox of a common front wheel drive vehicle, the boundary volume of the new device was defined by means of reverse engineering techniques. Two alternative architectures were proposed and compared to select the best one in terms of functionality. Then, the selected functional scheme was modeled and optimized by means of multiphysics simulations. The definition of a reiterative process, based on the use of a specific cost function, allowed to optimize the design variables and to obtain the final virtual prototype. In order to evaluate the effectiveness of the proposed device, a physical prototype was realized. First experimental tests were carried out validating the design process.     

一种兼容的低成本银行卡身份认证系统

文中针对现有磁性银行卡系统存在的伪卡隐患和IC银行卡的高成本,提出一种具有与IC银行卡同样高防伪性,同时兼备低成本的磁性银行卡身份认证系统.该系统基于JUNA轻量级数字签名技术,即用私钥对客户信息（含身份证号）进行签名,用生成的JUNA数字身份替代CVV码存储在磁道中,以确保银行和卡之间是发行和被发行的关系,并且以身份证作为安全可信根,在ATM机中加入居民身份证验证模块,保证客户和卡之间是持有和被持有的关系,从而能真正防止银行卡的伪造.由于该系统是基于现有磁性银行卡系统的改进,所以成本相较于IC银行卡系统大幅降低.分析表明,该系统具有易操作、低成本、高防伪的特性,推广性较强.     

虚拟仿真技术在电气工程类专业中的应用

电气工程类专业是我国高等教育体系中一个至关重要的组成部分,具有设备种类多、规模庞大、接线复杂、电流大、电压高等诸多特点.虚拟仿真技术可以给学生的学习提供一个安全健康的环境,还能优化电气工程教学效果.     

Continuously operating reference station and surveying applications in KSA

Recently, there is an increased interest in surveying applications based on Continuously Operating Reference Station (CORS) technology in the Kingdom of Saudi Arabia (KSA). Jeddah Municipality has started operating the first CORS network in KSA since 2007. This work discusses the new technologies used in Jeddah CORS network, the obtained accuracy and addresses, the different applications covered by CORS network such as cadastral surveying, road surveying, Lidar, among others. Moreover, the work presents the determination of the different transformation parameters between ITRF/WGS84 coordinate system and the local coordinate systems used in KSA. The purpose is to improve the communication abilities in order to operate modern smart cities. With full coverage and high accuracy of locations, Geographic Information System (GIS) and 3D models will be created to operate all aspects of life starting from the inside (the houses) and ending with saving the environment and the energy. Copyright © 2015 John Wiley & Sons, Ltd.     

Identities of *-superalgebras and almost polynomial growth

We study the growth of the codimensions of a *-superalgebra over a field of characteristic zero. We classify the ideals of identities of finite dimensional algebras whose corresponding codimensions are of almost polynomial growth. It turns out that these are the ideals of identities of two algebras with distinct involutions and gradings. Along the way, we also classify the finite dimensional simple *-superalgebras over an algebraically closed field of characteristic zero.