A Granularity-Aware Parallel Aggregation Method for Data Streams

0 IntroductionDtartaaf fsitcr ecaonmtsroiln , mwaenayth aeprpfloicraectiaosnts e ,tcs u,ccho maes fwroebm sdeirsvtircieb-,uted data sources at different geographiclocations .Distributedprocessing is the inevitable development trend for managingdata streams . Shared-nothing clusters can scale up to thou-sands of computers ,increase the available main memory,pro-cessors ,diskspace and bandwidthalongthe way,andtherebyprovide potential for high throughput and lowlatencies . Yetto date(As yet) ,th…     

Data Hiding and Security for XML Database： A TRBAC-Based Approach

In order to cope with varying protection granularity levels of XML (eXtensible Markup Language) documents, we propose a TXAC (Two-level XML Access Control) framework, in which an extended TRBAC (Temporal Role-Based Access Control) approach is proposed to deal with the dynamic XML data. With different system components,TXAC algorithm evaluates access requests efficiently by appropriate access control policy in dynamic web environment. The method is a flexible and powerful security system offering a multi-level access control solution.     

XML-based Framework of Parametric Design for Typical Parts

Parametric design of typical parts holds a very important position during process of product designs. In order to develop a parametric design system of typical parts compatible with heterogeneous CAD systems, this paper presents a framework of a network-oriented design system of typical parts, enabled by eXtensible Markup Language （XML）, capable of providing parametric design. Firstly, an overview of the framework is presented. In order to map the part feature hierarchy tree of 3D model into an XML tree, an XML-based part template is introduced. The methods of XML-based parametric design and parametric design navigation are described. Finally, an application example of prototype system under the Pro/Engineer platform is given. The application indicates that the proposed framework is valid for parametric design of typical parts/components in heterogeneous CAD systems.     

dr1127： A novel gene of Deinococcus radiodurans responsible for oxidative stress

The functional analysis of dr1127,a novel gene in Deinococcus radiodurans was performed in this pa-per. The dr1127 gene was found occasionally in our microarray and 2-DE gel experiments. Mutation of the dr1127 gene decreased the γ-radiation and H2O2 resistance of D. radiodurans,and weakened the scavenging abilities of cell extracts for free radicals (superoxide anion,hydrogen peroxide,and hy-droxyl radical). Further oxidative damage assays demonstrated that the purified DR1127 protein of D. radiodurans could bind to double stranded DNA in vitro and protect DNA from oxidative damage in this way. These results suggest that the dr1127 gene is an important gene that can maintain γ-radiation and oxidative resistance in D. radiodurans and may take part in the oxidative stress process.     

Combination Reduction： A SYN-Sequence Selection Strategy for Reachability Testing of Concurrent Programs

Reachability testing is an approach to testing concurrent programs, which can systematically exercise every partially ordered SYN-sequence without constructing the static model. In fact, not all the SYN-sequences need to be tested. This paper proposed a SYN-sequence selection strategy for reachability testing, which can reduce the number of SYN-sequences generated without decreasing the effectiveness of detecting programs＇ errors. We described a simple algorithm to implement the strategy, and then discussed several optimizations to the algorithm. Experiments have been carried out in a case study to verify the efficacy of the strategy.     

Challenges for Higher Education： A Reflection of My 100 Trips to China since 1981

1 Preface Thank you so much for giving me the honor to speak here today. There is a famous story about a bhnd person trying to figure out what an elephant looks like. When he touches the tail, he said the elephant looks like the tail. When he touches the ears, he said that the elephant looks like the ears. The reason is because the elephant is huge and unless you can examine both closely and afar, with open eyes, you may not see the whole Dicture.     

FluxExplorer： A general platform for modeling and analyses of metabolic networks based on stoichiometry

An increasing number of genomic and biochemical data make it possible to reconstruct biochemical net-works, especially metabolic networks, of an organelle or even a whole cell. Some methods for metabolism modeling and analyses in this field have been deve…     

Compensation for Land Loss in Reservoir Resettlement： A Case Study of The Three Gorges Project, China

This paper studies current policies in compensation for land lost due to construction of the Three Gorges project (TGP), China. In the case study of Kaixian County, the value of land in the peri-urban areas is underestimated. Some losses in land are tangible and thus measurable, but some losses are intangible and thus immeasurable. The land available in the resettlement areas is scarce and rarely of equivalent quality. This study suggests that the loss of agricultural land be compensated with alternative land and/or non-land-based livelihood strategies, including part compensation in monetary terms and preferential policies.     

A discussion on the upper limit of maturity for gas generation by marine kerogens and the utmost of gas generative potential： Taking the study on the Tarim Basin as an example

The experimental data yielded by Rock-Eval pyrolysis, kerogen atomic H/C, Py-GC and gold-tube sealing thermal simulation on the marine Cambrian-Ordovician source rock from the Tarim Basin revealed that the upper limit of maturity for natural gas generation or the ＂deadline of gas generation＂ for marine types Ⅰ and II kerogens is equal to 3.0% of vitrinite reflectance （Ro）; while the ＂deadline of gas generation＂ for type Ⅲ kerogens typically like coals is as high as 10% Ro. Thus, different organic matter has obviously different utmost maturities for gas generation. The mass-balance calculation by kerogen elements showed that when Ro〉1.5%, the utmost amount of gas generation for the marine type II kerogen is less than 185 m^3/t TOC, accounting for less than 30% of its total hydrocarbon generative potential; when Ro〉2.0%, it becomes 110 m^3/t TOC, less than 20% of the total hydrocarbon generative potential. The amount of the gas generative potential obtained by Rock-Eval is only around one tenth of the calculated value by the mass balance of kerogen elements at the same thermal evolutionary stage, while those by Py-GC and gold-tube sealing simulation are intervenient between the above two. The utmost of gas generative potential at the over 1.3% Ro stage is around 60--90 m3/t TOC, therefore, the amount of gas generation obtained by Rock-Eval is the minimum of gas generative potential, while that by the mass-balance calculation of kerogen elements is the maximum that the actual amount of gas generation should not exceed.     

Construction of habitat suitability models （HSMs） for benthic macroinvertebrate and their applications to instream environmental flows： A case study in Xiangxi River of Three Gorges Reservior region, China

Based on a long-term ecological monitoring,the present study chose the most dominant benthic macroinvertebrate(Baetis spp.)as tar-get organisms in Xiangxi River,built the habitat suitability models(HSMs)for water depth,current velocity and substrate,respectively,which is the first aquatic organisms model for habitat suitability in the Chinese Mainland with a long-term consecutive in situ measurement.In order to protect the biointegrity and function of the river ecosystem,the theory system of instream environmental flow should be categorized into three hierarchies, namely minimum required instream flow(hydrological level),minimum instream environmental flow(bio-species level),and optimum instream environmental flow(ecosystem level).These three hierarchies of instream environmental flow models were then constructed with the hydropogical and seighted usable area(WUA)method.The results show that the minimum required instream flow of Yiangxi River calculated by the Tennant method(10% of the mean annual flow)was 0.615m3s-1;the minimum instream environmental flow accounted for 19.22% of the mean annual flow(namely 1.182m3s-1),which was the damaged river channel flow in the dry season;and 42.91% of the mean annual flow(namely 2.639m3s-1)should be viewed as the optimum instream environmental flow in order to protect the health of the river ecosystem,maintain the instream biodiversity,and reduce the impact of small hydropower stations nearby the Xiangxi River.We recommend that the hydrological and biological methods can help establish better instream environmental flow models and design best management practices for use in the small hydropower station project.     

基于Bloom Filter的XML数据流压缩技术研究

现今,XML数据管理的一个重要问题是如何对XML数据进行高效的查询处理。以XML数据流的压缩为目标．提出了一种基于BloomFilter的XML数据流压缩技术,利用Dom4j的Aelfred2解析器对XMLSchema进行解析,构建dom4j树。采用压缩布鲁姆过滤器思想进行算术编码,达到压缩的目的。     

XML数据流小枝匹配算法

针对XML数据流可能具有复杂的递归层次结构,提出一种XML数据流小枝匹配算法TwigPM.通过获取查询节点的结构关系,进行有效的剪枝操作,减少了处理时间和数据所占用的内存空间.实验结果表明,算法具有高效性.     

基于Hole-Filler模型的XML流数据剪切分片技术

对基于Hole-Filler模型的XML流数据剪切分片问题,首先利用XML文档的Document Object Model(DOM)结构,根据节点扇出度提出了基于DOM的XML流数据剪切分片策略及其算法.然后,在此基础上,对标签结构进行剪切以确定文档的剪切点,提出了基于标签的XML流数据剪切分片算法,有效地减少了节点扇出度与阈值的比较次数.最后,提出了优化的剪切策略,根据阈值与节点扇出度的比值对XML子树加以整合,以减少碎片的产生.实验结果表明,XML剪切算法在剪切时间、分片粒度等方面都有较好的性能.     

一种基于VFDT算法的同构XML流分类方法

为了对动态XML文档流进行分类,以VFDT算法为核心,提出了一种针对相同结构的XML文档流分类算法,该算法将XML流中文档解析并用来动态地构造分类器。实验表明,该方法在XML流上数分类的精确度能够达到XML文档静态分类的水平。     

一种基于数据绑定的Java平台下XML数据操作新方法

基于XML与Java凭借跨平台的优势及其互补性的特点,为下一代Web应用开发的基础数据描述格式与主要开发环境,针对Java处理XML数据的几种接口的缺陷,研究了通过XMLSchema到Java类的映射,实现基于数据绑定的Java应用对XML数据的操作,并用典型实例给予验证.该方法较SAX及DOM具有能够双向数据操作,对系统资源要求低的特点,特别适合XML文档表示配置信息的情况.     

数据流管理与挖掘研究

20世纪末,为适应网络监控、商业交易管理和分析等应用的要求,数据流技术应运而生;该文回顾了近年来国内外在该领域的研究进展,总结了数据流的特点、模型及其算法,对数据流管理和挖掘的关键技术进行了分析,并进一步提出了数据流技术研究的方向。     

XML数据存储管理技术

随着XML的出现，计算机领域出现了一个新的发展方向。XML不仅作为一种互联网上数据表示和交换的标准，而且被应用于搜索引擎、电子商务、电子数据交换等很多方面，因此受到了广泛的关注。为了更好的发挥XML的潜能和作用，必须有一种完善的技术对XML数据进行存储管理。本文详细分析了当前存在的XML数据存储管理技术及其分类方法，指出了这些方法存在的不足。然后，提出了基于映射对象的XML存储管理技术分类方法。最后，对一个完善的XML数据管理技术应当具有的功能进行了探讨。     

一种XML数据到结构化数据的转换方法

分析半结构化树状层次结构的XML文档的结构特征,描述XML结构与关系数据库的对应关系．给出XML文档的DTD中各主要元素与关系数据模型之间的映射规则,设计转换规则脚本的自动生成算法和数据转换算法．     

一种快速解析XML的网络应用架构

由于XML的灵活性和自我描述复杂性，在基于Web的服务器应用中往往会消耗大部分服务器处理能力．本文提出一种采用专用硬件加速XML处理速度的网络架构，可以极大地减少服务器解析XML的负担．