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1.
开放网格服务体系结构(OGSA)中的服务容错需要可扩展的、灵活的容错框架,能够支持容错策略与应用程序的分离.针对这一需求,提出了一种基于OGSA的层次式容错处理框架.框架能根据不同服务质量需要灵活设置故障处理策略,选择不同容错机制;在此框架下,实现了基于服务实例池的热备份以及基于服务检查点的服务重构等容错机制.该容错框架及机制应用于HUSTgrid平台,较好地满足了网格服务的容错需要,并在应用系统CoGIS中得到了验证.  相似文献   

2.
对网格技术和工作流技术进行了概括性介绍,然后简要介绍了开放网格服务体系结构(OGSA)和网格服务的概念及特点.根据对工作流应用领域的深入了解,总结出网格技术在工作流领域中的主要应用需求,在此基础上提出了基于网格服务的工作流的构想和基本模型.  相似文献   

3.
将Web服务技术引入网格研究领域,有助于解决网格研究所面临的应用集成、资源共享、系统互操作和标准化等问题.本文在网格协议体系结构和开放网格服务架构(Open Grid Services Architecture,OGSA)的基础之上,将探讨网格系统与web服务的结合.首先讨论了网格功能模型,基于OGSA框架提出了Web服务的网格层次体系结构,并将Web服务工作流引入到网格任务描述中,给出一种Web服务与网格技术相融合的机制.  相似文献   

4.
一种基于OGSA的网格信息服务系统   总被引:5,自引:0,他引:5  
网格信息服务系统是网格系统中的重要组成部分.由于网格技术和Web服务融合为开放的网格服务架构(OGSA),原有的网格信息服务系统需要重新构建.本文从分析传统的网格信息服务系统MDS,R-GMA和Hawkeye入手,研究了最新开放的网格体系结构的规范,构建了一种具有森林结构的基于OGSA的网格信息服务系统模型OGIS,描述了主要模块的功能和实现方法,探讨了基于OGSA的网格信息服务系统  相似文献   

5.
一种基于网关的网格数据互操作框架   总被引:1,自引:1,他引:0  
针对网格数据互操作中存在的存储资源异构、作业需求多样、故障多发等问题,提出了一种基于网关的数据互操作框架--数据网关.它是专门的数据互操作解决方案,可以独立处理数据互操作作业,促进网格互操作任务的并行化处理.数据网关采用了一种基于ClassAD的作业描述语言,可以描述任意的服务、数据或者约束条件,并引入了插件式的扩展机制,大大提高了数据网关对异构存储资源的扩展性.数据网关的动态协议选择机制和故障恢复机制可以为上层应用提供一个良好的运行环境,由此增强了系统的可用性.实验表明,数据网关可以快速实现异构网格设施之间的数据互操作,在无人值守的情况下自动处理各种底层网络和服务故障,有效地完成各种数据互操作任务.  相似文献   

6.
研究构建中国地震减灾网格试验床的关键技术.基于OGSA和GT3体系结构,提出了计算网格平台的编程模型,分析了模型的网格Web应用层、网格Web服务器层和网格资源/服务层之间的关系.设计并实现了模型的关键组件,并给出了基于GSI的模型安全解决方案,最终构建了一个计算网格平台,并在平台上实现了云南地区的地震应力触发计算.计算结果表明,该平台满足网格计算的需求,并能提高计算效率.  相似文献   

7.
OGSA 作为一个通用的网格计算框架,解决了CSCD环境中诸多问题,为网络化协同设计提供了新的解决途径.以WSRF规范为基础,利用OGSA网格架构作为协同设计网格的基础平台,研究了网格技术在网络化协同设计系统中的应用问题,协同设计网格的概念,对协同设计网格功能进行需求分析,重点提出了开放式协同设计网格体系结构及协同设计网格环境下协同设计过程,并深入分析了协同设计网格倒丶际?为进一步深入研究协同设计网格及其实现提供了解决思路和研究基础.  相似文献   

8.
网格系统的故障检测与告警   总被引:1,自引:0,他引:1  
及时发现网格系统的故障,是提高网格系统运行可靠性的关键.为此,在实现网格资源监控与网格任务监控的基础上,设计并实现了网格故障检测与告警系统.描述了故障检测与告警系统的整体框架架构及实现机制.本系统采用主动式故障检测,主动轮流咨询分布在网格节点上的代理Agent和分布在服务器上的任务监控代理Agent,基于自适应条件分别判断网格资源和网格任务是否运行正常,当出现故障或错误时及时发出告警,并显示告警信息.  相似文献   

9.
通用网格容错框架研究   总被引:4,自引:0,他引:4  
针对网格计算可靠性需求,提出一套网格计算容错框架,该容错框架包括两个方面:网格错误检测与网格错误处理.本容错框架通过提供一种层次式错误检测方式以及基于策略的通用错误处理方式来保证网格计算的可靠性.错误检测服务按照层次方式组织,最底层是本地错误检测器,它负责收集被检测对象的信息,发送到中间层的数据收集器,中间层数据收集器按照列表方式发送被检测对象的信息到顶层数据收集器.当错误检测器检测到运行错误时,按照决策分析的方法来提供灵活的错误处理方式.对系统的性能评测表明提出的通用网格容错框架具有很好的扩展性、高效性以及较低的额外开销.  相似文献   

10.
网格安全已成为网格计算系统中的一个重要问题,本文首先介绍了网格技术和网格安全的概念以及需求,剖析了Globus下的网格安全基础设施和基于OGSA的网格安全体系结构两种典型的网格安全解决方案,并在Linux环境下进行了基于GT4的网格安全环境构建。  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.  相似文献   

13.
王慧 《科技信息》2008,(10):240-240
Wuthering Heights, Emily Bronte's only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.  相似文献   

14.
The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3~4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰~ -7.8‰, PDB) and matrix dolomites (-6.6‰~ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084~0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078~0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.  相似文献   

15.
Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.  相似文献   

16.
以AC-13级配为基础,将橡胶颗粒代替部分集料掺入混合料中,以低温弯曲试验为评价方法对不同橡胶颗粒掺量下沥青混合料的低温抗裂性进行研究,并引入应变能密度值对混合料的低温抗裂性进行综合评价.试验结果表明:橡胶颗粒沥青混合料试件的破坏微应变均超过2 300,满足冬寒区的技术指标;无论是否掺加橡胶颗粒,随着温度的下降,沥青混合料破坏时的最大弯拉强度增大,弯拉应变降低,劲度模量增大;弯曲应变能密度在胶粒掺量为1%左右时具有较大的弯曲应变能密度值,此时橡胶颗粒沥青混合料具有较好的低温抗裂性.  相似文献   

17.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

18.
Quality traits in wheat (Triticum aestirum L.) were studied by quantitative trait locus (QTL) analysis in a recombinant inbred line (RIL) population, a set of 131 lines derived from Chuan 35050 × Shannong 483 cross (ChSh). Grains from RILs were assayed for 21 quality traits related to protein and starch. A total of 35 putative QTLs for 19 traits with a single QTL explaining 7.99-40.52% of phenotypic variations were detected on 10 chromosomes, 1D, 2A, 2D, 3B, 3D, 5A, 6A, 6B, 6D, and 7B. The additive effects of 30 QTLs were positive, contributed by Chuan 35050, the remaining 5 QTLs were negative with the additive effect contributed by Shannong 483. For protein traits, 15 QTLs were obtained and most of them were located on chromosomes 1 D, 3B and 6D, while 20 QTLs for starch traits were detected and most of them were located on chromosomes 3D, 6B and 7B. Only 7 QTLs for protein and starch traits were co-located in three regions on chromosomes 1D, 2A and 2D. These protein and starch trait QTLs showed a distinct distribution pattern in certain regions and chromosomes. Twenty-two QTLs were clustered in 6 regions of 5 chromosomes. Two QTL clusters for protein traits were located on chromosomes 1D and 3B, respectively, three clusters for starch traits on chromosomes 3D, 6B and 7B, and one cluster including protein and starch traits on chromosome 1D.  相似文献   

19.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.  相似文献   

20.
赵英华 《科技信息》2008,(12):219-220
0.Preface China has long been boasting of its colorful and immense culture which comprises of Taoism,Confucianism and Buddhism.The interwoven influence among the religions on Chinese way of thinking,on the nation's behavior in their social life throughout the long history is beyond list.  相似文献   

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