桌面式天线虚拟实验系统

将天线数值仿真技术与虚拟现实技术结合,构建一个桌面式天线虚拟实验系统,可以解决天线实验课开设成本高、场地受限等问题.     

桌面虚拟化技术在多媒体教室管理中的应用

本文分析了多媒体教室管理的现状,提出通过桌面虚拟化技术解决日常管理中存在的管理难度大、维护人员多、管理效率低等问题,努力提高多媒体教室管理的集中化、安全性和高效率。     

Development of new-concept desk top size machine tool

A desktop multiprocess machinery has been designed that has two concepts: miniaturizing of machine tool and multiprocessing with a same machine tool. The prototype of desktop multiprocess machinery is developed in this study. This is tabletop size machine tool that has five changeable machining heads. Outline of main body and machining head are presented.In order to know the basic accuracy of desktop multiprocess machinery, experimental evaluation is carried out. Machining head setting error, stiffness of multiprocess machinery and straightness of X, Y, Z stage is measured. To study the basic performance of desktop multiprocess machinery, a complex machining experiment is carried out with the developed machine tool. The complex machining consists of three steps: electrode machining by milling, hole shaping by EDM, and hole finishing by ECM. These steps are performed in sequence on the same machine tool. The complex machining is successfully carried out. In order to evaluate the desktop multiprocess machinery from environmental point of view, machining energy, volume of machining liquid, and installation space of desktop multiprocess machinery are measured. The measured values are compared with estimated values with conventional machine tools. The machining energy, the volume of machining liquid, and the installation space of desktop multiprocess machinery are smaller than those of conventional machine tool.     

个人信息检索概述

个人数字信息检索技术随着搜索技术的发展而蓬勃兴起,满足了人们对存储在个人电脑中的数据信息的检索需要。讨论了个人信息检索技术的历史、现状,比较了现有的桌面搜索产品,总结了个人信息技术面对的主要问题。在参考其他个人信息检索研究的基础上,针对未开放格式文件的检索问题,提出了个人信息检索模型的改进。     

面向虚拟桌面内外部数据流的安全控制机制研究

桌面虚拟化需要借助虚拟桌面协议来实现内部应用数据和外部操作平台的数据交互。然而该类协议中的数据流控制机制并不完善,存在数据非法交互的安全隐患。为解决该问题,基于网关模式提出了一种面向虚拟桌面内外部数据流的安全控制机制SCIED。它不仅能对协议中的虚拟通道进行全面管控,避免修改协议和大量的终端,还具有较高的兼容性、拓展性。将它部署于网关并用于防护边界攻击,能显著减少服务器端的负载和安全隐患。实验表明,该SCIED能够有效保证数据流的安全交互,并且对现有桌面会话的性能影响较小。     

DMI标准的MIF到MIB转换器的研究与实现

在实现DMI与SNMP两种管理框架转换的过程中,最关键的问题是要完成这两个框架中,对于可管节点信息定义的转换,即将DMI中的MIF转换为SNMP中的MIB。DMTF根据这个需求制定了一套转换标准,但是实际应用中的工业标准和前者存在较大的差异。深入分析了这两套标准,探讨了如何实现一个通用的MIF到MIB的转换器,并给出了实现该转换器的优化模块设计图。     

Boosting gLite with cloud augmented volunteer computing

The paper details the result of the EU FP7 EDGI project focusing on the cloud developments and usability improvements. Volunteer desktop grids, like BOINC, are designed to handle millions of parameter sweep type jobs and millions of desktop machines as worker nodes. Seamless transfer of gLite jobs to desktop grids was already implemented by EDGI; however this huge number of DG resources could not be utilized efficiently due to slow completion time caused by unpredictable behavior of the volunteer resources. The paper details how clouds have been utilized to shorten completion time on the EDGeS@home volunteer desktop grid to boost the performance of the supported gLite VO and also details how this service can be exploited by the gLite user communities of EGI (European Grid Initiative) all over Europe.     

桌面云系统研究及多节点容灾方案分析

桌面云系统是一种基于云计算技术的集中式的客户终端解决方案。在用户侧部署功能简单的瘦客户机,具体的计算以及存储依靠云端的服务器系统。在客户终端大量部署的应用场景当中,桌面云系统能够降低运维成本,提供更好的保密性以及安全性,还能提供移动办公的能力。在节能减排方面,桌面云系统的平均能耗也低于传统终端。多节点部建设云端桌面云系统能够提高系统的高可用性,在某个节点服务器发生故障时,在网络可达的情况下,用户可将虚拟终端迅速迁移至其它节点,从而保证上层业务的连续性。     

中国联通信息化云计算工作探讨

在云计算时代,运营商需要将自身网络智能和控制能力与云服务有机结合,提出集成、高效、可靠的云平台信息化发展战略。文章以中国联通云平台试验工作为依托,分析目前运营商信息化云计算发展思路和标准化工作,并根据实际情况介绍桌面云和绿色数据中心的建设情况,为电信级的云服务运营提供参考依据。     

Effectiveness of a personalized ventilation system in reducing personal exposure against directly released simulated cough droplets

The inhalation intake fraction was used as an indicator to compare effects of desktop personalized ventilation and mixing ventilation on personal exposure to directly released simulated cough droplets. A cough machine was used to simulate cough release from the front, back, and side of a thermal manikin at distances between 1 and 4 m. Cough droplet concentration was measured with an aerosol spectrometer in the breathing zone of a thermal manikin. Particle image velocimetry was used to characterize the velocity field in the breathing zone. Desktop personalized ventilation substantially reduced the inhalation intake fraction compared to mixing ventilation for all investigated distances and orientations of the cough release. The results point out that the orientation between the cough source and the breathing zone of the exposed occupant is an important factor that substantially influences exposure. Exposure to cough droplets was reduced with increasing distance between cough source and exposed occupant.