An Effective Cache Replacement Algorithm in Transcoding-Enabled Proxies

In this paper, we address the problem of cache replacement for transcoding proxy caching. Transcoding proxy is a proxy that has the functionality of transcoding a multimedia object into an appropriate format or resolution for each client. We first propose an effective cache replacement algorithm for transcoding proxy. In general, when a new object is to be cached, cache replacement algorithms evict some of the cached objects with the least profit to accommodate the new object. Our algorithm takes into account of the inter-relationships among different versions of the same multimedia object, and selects the versions to replace according to their aggregate profit which usually differs from simple summation of their individual profits as assumed in the existing algorithms. It also considers cache consistency, which is not considered in the existing algorithms. We then present a complexity analysis to show the efficiency of our algorithm. Finally, we give extensive simulation results to compare the performance of our algorithm with some existing algorithms. The results show that our algorithm outperforms others in terms of various performance metrics.     

加入世贸 驾驭世贸 兴利防害 乘势发展——谈谈发展中国家面临的严峻挑战及应对措施

世界贸易组织是一个以规则为基础的多边贸易体制 ,它追求以贸易无差别、贸易自由化、贸易透明、促进公平为基本原则 ,促进市场开放 ,为各国企业营造一个相对合理的自由、非歧视、可预见、平等竞争的全球市场经济环境。在经济逐步全球化的今天 ,发展中国家若要大步发展本国经济 ,不断提高本国的经济实力 ,加入世贸无疑是一个较好的选择。发展中国家加入世贸必须掌握三条原则 :一是了解世贸 ,驾驭世贸 ;二是掌握规则 ,应用规则 ;三是扬长避短 ,发挥优势     

入世对国内证券公司的影响

我国的证券公司只有十几年的发展历史，整体信誉不佳，抗风险能力较弱，尚待规范和强大。我国加入世界贸易组织后证券业的对外开放给处于发展壮大中的国内证券公司带来了各种不利和有利的影响，其中有利的影响是主要的。在中国市场上，中外证券公司各有优势和劣势。在入世的新形势下，国内证券公司需要在筹资、人力资源管理、业务经营、组织结构等方面进行战略改革以不断积累和增强自己的优势。     

基于内容模块化的网页快速浏览技术

在万维网(WorldWideWeb)庞大的信息海洋中,如何提高信息检索和浏览效率,一直是重要的研究内容之一。文章中提出了将一复杂网页的内容按照模块化方式进行组织和使用的新思想,通过对HTML语言的简单扩充和对浏览器与Web服务器的相应改进,新浏览器可使用户有效避免对无关网页的浏览和减少网页中无关信息的传输,明显提高了网页浏览速度,尤其是对拨号上网用户,其效果更为明显。     

网络地理信息系统的特点与实现方法

国际互联网与地理信息系统结合而形成的网络地理信息系统 (WebGIS)是目前地理信息系统发展的一个热点。文章在指出当今WebGIS与传统GIS相比的新特点后 ,提出了WebGIS实现的几种方法 ,并简要介绍了目前WebGIS的国内外产品     

Irradiation embrittlement monitoring of WWER-440/213 TYPE RPVs

In the paper the main goals and progress of the surveillance specimen programme for the RPVs WWER-440/213 in Jaslovské Bohunice V-2 and Mochovce NPPs are presented. At Jaslovské Bohunice V-2, the standard surveillance specimen programme (SSSP) was finished and so-called ‘Extended Surveillance Specimen Programme’ (ESSP) was prepared on the base of its critical analysis. For first two units of the Mochovce NPP completely new programmes of irradiation embrittlement monitoring called ‘Modern Surveillance Specimen Programme’ is prepared. It is based on the experience with SSSP and ESSP as well as the recommendations of IAEA experts. This programme will serve for Mochovce NPP during all planned service life. The experience of ESSP application on the 3rd and 4th units in Jaslovské Bohunice V-2 NPP are presented in the paper too.     

中国古代丝绸文化的历史地位

中国古代丝绸文化,是中国传统文化的精华之一,它曾在中国文明史和世界文明史上占有相当重要的地位。本文论述了中国古代丝绸文化对中国物质文明和精神文明的影响,对世界文明的影响。     

Display and Interactive Languages for the Internet: HTML, PDF, and Java

The rapid rise of the Internet has lead to new technologies. These include HTML, the basic markup language for pages on the World Wide Web; PDF, a file format designed for precise layout control of documents like working papers and journals, and Java, a general purpose language ideally suited for use on the Internet. This paper introduces these technologies.     

Assessment of structural steel from the World Trade Center towers, part V: forensic photographic evidence of tower collapse initiation and progression

Photographic forensic evidence for the global collapse of the World Trade Center (WTC) towers was developed as part of the National Institute of Standards and Technology (NIST) WTC collapse investigation. The libraries accumulated during the Federal Emergency Management Agency/American Society of Civil Engineers study and NIST investigations were searched for images that showed gross building distortions preceding or during the collapse events. Frames or images showing draw-in of the cast face of WTC 2 and the south face of WTC 1 were analyzed to map the distortion field, which was tracked over time. The inward distortions increased in magnitude as the building burned, reaching a maximum at the time of collapse. Evidence of dropped floors within the towers before global collapse was developed, as was evidence of the kinking and rotation of the top portion of WTC 2 just before and during collapse.     

走出城市异化的困境——城市生活形态的延续与完善是关键

本文对城市的异化进行了总结与分析。文章提出在城市设计中应回归日常的生活世界,因此多元的日常生活是我们的出发点,多元化的生活形态是我们的目标。其关键在于延续与完善我们的生活形态,这样每一种生活形态的城市中才有自己的立足点和发展可能性,才能走出城市异化的困境。