Application protocols and performance benchmarks

The authors present results from performance measurements of application services. They have chosen widely available implementations of the file transfer protocols File Transfer Access and Management (FTAM) and FTP, and the transaction protocols Remote Operations Service Element (ROSE) and Sun's Remote Procedure Call (SunRPC). The measurements have all been run on the same Sun 3/60 workstations over Ethernet, using protocol-independent benchmarks. A tool called SICS Protocol Implementation Measurement System (SPIMS) is used for the measurements. It is structured as a protocol, with two peer entities communicating with each other using the service of the measured protocol. The authors describe how SPIMS can be used to measure response time, throughput, and the time to open and close connections. They describe the protocols and their implementations, and draw some conclusions, and present and comment on the results     

Multimedia retrieval benchmarks

Multimedia retrieval systems' development has long been challenged by the lack of standard benchmarks for evaluating and comparing the performance of emerging techniques. However, two recent benchmarking efforts, TREC Video Retrieval Evaluation (TRECVID) and the IAPR TC-12 Benchmark for Visual Information Search, show great promise for letting the multimedia retrieval community collaborate on advancing the state of the art.     

现实标准和32位MCU

当为下一代控制应用选择32位MCU时,必须考虑一点,就是面对某一实际的应用,不同供应商的处理器虽然在数据手册上看起来或多或少有些相似,但实际上是非常不同的.虽然数据手册中的规范和Dhrystone(处理器整型数计算能力)MIPS处理能力给出了一个粗略的评估标准,但必须考虑得更深入以保证MCU有足够的吞吐量和过载余量来满足当前和未来的应用需求.     

剖析基准测试

基准是一个您能用以对两个或更多相似选择对象的价值和质量进行一致的测量、量化和比较的参考点,这些选择对象包括商业过程、工具和嵌入式处理器等.     

Energy characterization of mobile devices and applications using power-thermal benchmarks

Power consumption and heat dissipation are the major factors that limit the performance and mobility of battery-powered devices. As they become key elements in the design of mobile devices and their applications, different power and thermal management strategies have been proposed and implemented during the previous years in order to overcome the mobility limitation due to the battery lifetime. A new energy management approach is to build energy-aware applications so that we have knowledge on the consumed energy while the device is running. In this paper we define two new types of benchmarks, called power and thermal benchmark, which are software applications intended for the run-time system level to provide power and thermal characterization. These benchmarks are an easy way for the applications to adapt their execution pattern, in order to finish their tasks both in time and in the battery lifetime.     

Two benchmarks to facilitate the study of compact thermal modelingphenomena

The paper discusses two benchmark cases to facilitate the study of compact thermal models for the purpose of component thermal characterization. The benchmarks represent idealised concepts of respectively a leaded package (PFQP-style) and an area-array package (BGA-style). Two different boundary conditions sets are included because both package types require such. The objective of the paper is to formulate a framework that can be used by everyone working in the field. In this way, comparison of results emerging from alternative approaches in defining compact models becomes much easier. The benchmarks are also prepared for the study of time-dependent compact models, but in this paper only steady state models are discussed. The paper also proposes a definition of Boundary-Condition-Independence and discusses a possible division of thermal characterization responsibilities between component manufacturers and their customers     

数字水印研究中常用的测试指标(下)

数字水印作为数字媒体版权保护的有效手段。受到极大关注，钽却没有一个良好的衡量手段来对数字水印算法作出合理的评测，本文总结了目前比较流行的数字水印算法衡量手段以及几种有效的数字水印的攻击手段，旨在帮助全面评测水印算法的性能，进而帮助改进数字水印算法，使数字水印算法具有更好的隐形性、稳健性、安全性，以促进数字水印走向实用化。     

数字水印研究中常用的测试指标(上)

数字水印作为数字媒体版权保护的有效手段，受到极大关注，但却没有一个良好的衡量手段来对数字水印算法作出合理的评测。本文总结了目前比较流行的数字水印算法衡量手段以及几种有效的数字水印的攻击手段，旨在帮助全面评测水印算法的性能，进而帮助改进数字水印算法，使数字水印算法具有更好的隐形性、稳健性、安全性，以促进数字水印走向实用化。     

安全存储与云存储安全

云存储是整个存储业发展的趋势。随着信息技术的高速发展和社会经济的发展进步,社会公众服务对信息化的依赖性越来越高,整个社会正逐步进入＂数字化＂社会,信息技术也已经进入＂云＂时代,而这些都对数据存储带来了爆炸式的增长,对传统存储系统带来了新的挑战,传统存储系统不管是在建设和运营成本方面还是在动态增长方面,都不能适应＂绿色环保、节能减排＂的社会发展步伐。     

Broadband wireless access with WiMax/802.16: current performance benchmarks and future potential

The IEEE 802.16 family of standards and its associated industry consortium, WiMax, promise to deliver high data rates over large areas to a large number of users in the near future. This exciting addition to current broadband options such as DSL, cable, and WiFi promises to rapidly provide broadband access to locations in the world's rural and developing areas where broadband is currently unavailable, as well as competing for urban market share. WiMax's competitiveness in the marketplace largely depends on the actual data rates and ranges that are achieved, but this has been difficult to judge due to the large number of possible options and competing marketing claims. This article first provides a tutorial overview of 802.16. Then, based on extensive recent studies, this article presents the realistic attainable throughput and performance of expected WiMax compatible systems based on the 802.16d standard approved in June 2004 (now named 802.16-2004). We also suggest future enhancements to the standard that could at least quadruple the achievable data rate, while also increasing the robustness and coverage, with only moderate complexity increases     

Encrypted Storage and Retrieval in Cloud Storage Applications

Problems with data security impede the widespread application of cloud computing. Although data can be protected through encryption, effective retrieval of encrypted data is difficult to achieve using traditional methods. This paper analyzes encrypted storage and retrieval technologies in cloud storage applications. A ranking method based on fully homomorphic encryption is proposed to meet demands of encrypted storage. Results show this method can improve efficiency.     

云存储应用中的加密存储及其检索技术

云计算自身的数据安全问题阻碍其推广应用。通过对数据进行加密可以保护企业及个人用户的数据隐私。对加密数据有效检索难以通过传统信息检索方式实现。文章在分析云存储应用中的存储安全技术基础上,针对加密存储的需求,基于常见的加密检索方法和相关技术,结合自己的研究成果,提出了一种基于全同态加密的检索方法,该方法能在一种程度上提高检索效率。     

基于FreeNAS的NFS存储和ISCSI存储优化的探究

为解决虚拟化条件下重要数据及服务器相关日志数据优化的问题,文章提出了FreeNAS的NFS和ISCSI优化存储结构,结构基于IP网络的网络存储备份系统。测试结果表明,网络存储设备本地化使用优化了存储结构,提高了数据安全性。     

光纤通道网络与存储技术

存储区域网(SAN)是近几年新发展的存储技术,它真正的综合了直连存储(DAS)和网络直连存储(NAS)两种存储解决方案的优势,为我们更加安全、快速、可靠地进行数据存取提供了可能。可以预见,存储区域网技术是将来存储技术的发展趋势。简要介绍了这种技术的基本概念,并着重讨论了它的应用优势以及最新的技术发展情况。     

数字存储媒体-命令和控制

对DSM－CC涉及的不同功能作了较详细的介绍。DSM－CC是宽带网络用于传输多媒体服务的多个协议范围的集合，特别适合广播电视网络。     

存储与计算的分离

首先介绍了当前存储应用的新特性，认为以服务器为中心的DAS访问模式越来越难以满足现代存储应用的需求．解决问题的关键是将访问模式从以服务器为中心转化为以数据和网络为中心，这推动存储与计算的分离。接着介绍了存储与计算的差异和日前存储资源与计算资源分离的可能性、必要性．以及分离方式和分离后的模式等。认为传统的DAS存储模式已经开始衰落，而新的以NAS／SAN为代表的网络存储系统已经开始迅速增长；NAS和SAN并非相互竞争，而是相互补充。只有将二者融合，才能够将各自的扰势充分发挥出来。     

零距离存储

网络数据和信息的急剧增加,带来了存储服务市场的迅速发展。据权威研究机构的预测,到2003年,全球存储市场的总量将会超过400亿美元。目前,最引人注目的网络存储解决方案是存域网和附网存储。它们虽然各有优势,又各有各自的问题,但目的都是一样的,这就是消除信息数据和用户之间的距离,实现零距离存储。     

基于存储虚拟化技术的双活存储系统的设计与实现

为了促使双活存储向虚拟化、高效化方向不断发展,提高信息数据的存储效率和利用率,文中以“存储虚拟化技术”应用为例,设计了一款功能完善、实用性强的双活存储系统。首先,介绍了相关技术理念;其次,分析了双活存储系统的建设背景;最后,从双活存储系统实施风险分析、双活存储系统方案设计、双活数据中心实施方案、实施方案的结果效益等4个方面入手,完成了对双活存储系统的科学设计。结果表明,在存储虚拟化技术的应用背景下,文中所设计的双活存储系统运行正常、可靠、稳定,各个功能模块满足了设计要求。希望通过这次研究,为技术人员提供有效的借鉴和参考。     

IT支撑系统中的存储特征需求及云存储方案研究

本文通过分析各类IT支撑系统应用的存储技术特征,为不同类应用选择恰当的存储方案,有助于降低系统建设成本、提供差异化存储服务,同时,通过研究云存储技术及对应适用场景,对于推进云计算在IT领域的应用具有重要意义.