939 resultados para web platform
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形式化定义了Web服务组合过程中的5种基本逻辑结构,并采用有色Petri网表示,然后将其抽象为服务的代数运算;在此基础上,提出了经过服务运算后得到的服务的性质及组合服务的构造方法;最后通过实例分析,说明该建模方法可以保证组合的服务是正确且可终止的。
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Web服务组合的正确性验证对提高软件开发效率、实现服务增值具有重要意义。为从高层抽象层次研究Web服务组合的正确性及其形式化验证方法,考虑到Web服务组合中的实时特征,在采用软件体系结构描述语言XYZ/ADL对Web服务组合进行描述的基础上,将其实时描述部分XYZ/RE转换至时间自动机模型,组合后系统应满足的性质用分支时序逻辑CTL公式表示,最后应用模型检测工具UPPAAL实现了Web服务组合正确性的自动化验证。
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提出一种资源敏感的性能诊断方法.对于Web应用事务,该方法利用资源服务时间对于不同负载特征相对稳定的特点建立性能特征链,并依据运行时资源服务时间异常实现性能异常的有效检测、定位和诊断.实验结果表明,该方法可适应系统负载特征变化,诊断各种资源使用相关的性能异常.
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Huazhong Univ Sci & Technol, Natl Tech Univ Ukraine, Huazhong Normal Univ, Harbin Inst Technol, IEEE Ukraine Sect, I& M/CI Joint Chapter
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语义Web是现有Web的一个语义延伸,目标是使Web的应用具有一定的智能,能够进行更准确的信息搜索和一定的决策支持,帮助用户自动完成一些任务。语义Web的实现需要人工智能、数据库等领域的技术支持,需要对已有的技术进行改进和扩展,也需要对现有技术本身如ECA规则进行更深入的研究从而进一步将其扩展到语义Web。自动推理技术是语义Web实现的基础之一,而ECA规则可以为系统增加反应性行为能力,本文围绕自动推理和ECA规则,主要进行了如下研究:(1) 一阶逻辑推理技术对语义Web的推理支持。分析了语义Web语言需要的表达能力,对现有描述逻辑工具、一阶逻辑工具的能力进行了考察。现有的描述逻辑工具不足以处理应用所需要的更丰富的语言成分、任意的一阶逻辑规则等,而一阶逻辑自动定理证明工具和有限模型查找工具有分别都有较好的研究成果。把语义Web的推理问题化成可满足性判定问题后,本文给出了一阶逻辑定理证明器和有限模型查找器形成的并发过程进行可满足性判定的方法。这样既可以解决描述逻辑工具的不足,并可弥补定理证明器对可满足的公式推理的不完备性。(2) ECA规则(主动规则)的终止性分析。终止性是主动规则最重要的行为性质,不终止是由于主动规则的级联触发造成的,意味着定义错误。终止性检查通常是不可判定的。有效的静态分析方法是主动规则得以实际应用的保证。静态分析的关键是合适的数据库状态描述,本文给出用约束表示数据库状态的方法,通过模拟规则执行,使用约束求解进行条件计算和重复状态检查,判断主动规则集合是否终止。用约束精确表示了数据库状态,在规则处理中考虑了执行语义,从而得到更精确的终止性结论。
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语义Web和Web服务是当前热门的应用技术,而两者的结合——语义Web服务将在未来几年具有极大的应用前景。语义使得~Web~服务的自动发现和自动组装变得非常容易、高效,但是随之而来的问题是如何确保自动组装的~Web~服务组合在本体知识库的状态下是一致的,并且在执行过程中也始终保持一致。 本文介绍了一种基于路径的语义Web服务组合验证方案,通过对服务组合中的单个Web服务进行输入、输出、前置条件和执行效果(IOPE)进行语义标注,旨在找出组合执行过程中在任何结点处可能存在的不一致性。文章定义了显式不一致性和隐式不一致性,首先提出了语义Web服务前置条件和执行效果的正规化表示方法,然后介绍了顺序和并发执行的多个Web服务之执行效果自动化累积算法,接下来给出了基于路径的一致性验证算法。文章还给出了实现该验证方案的平台架构,给出了相关实验过程和结果。 文章还完整地介绍了中科院某研究所本体的构造和扩充过程,定义了研究生毕业申请服务组合,并介绍了服务的IOPE标注,最后运用验证方案对该组合进行验证,给出了验证结果。
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With long-term marine surveys and research, and especially with the development of new marine environment monitoring technologies, prodigious amounts of complex marine environmental data are generated, and continuously increase rapidly. Features of these data include massive volume, widespread distribution, multiple-sources, heterogeneous, multi-dimensional and dynamic in structure and time. The present study recommends an integrative visualization solution for these data, to enhance the visual display of data and data archives, and to develop a joint use of these data distributed among different organizations or communities. This study also analyses the web services technologies and defines the concept of the marine information gird, then focuses on the spatiotemporal visualization method and proposes a process-oriented spatiotemporal visualization method. We discuss how marine environmental data can be organized based on the spatiotemporal visualization method, and how organized data are represented for use with web services and stored in a reusable fashion. In addition, we provide an original visualization architecture that is integrative and based on the explored technologies. In the end, we propose a prototype system of marine environmental data of the South China Sea for visualizations of Argo floats, sea surface temperature fields, sea current fields, salinity, in-situ investigation data, and ocean stations. An integration visualization architecture is illustrated on the prototype system, which highlights the process-oriented temporal visualization method and demonstrates the benefit of the architecture and the methods described in this study.
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Here, we report a sensitive amplified electrochemical impedimetric aptasensor for thrombin, a kind of serine protease that plays important role in thrombosis and haemostasis. For improving detection sensitivity, a sandwich sensing platform is fabricated, in which the thiolated aptamers are firstly immobilized on a gold substrate to capture the thrombin molecules, and then the aptamer functionalized Au nanoparticles (AuNPs) are used to amplify the impedimetric signals.
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In this paper, the characterization and application of a chemically reduced graphene oxide modified glassy carbon (CR-GO/GC) electrode, a novel electrode system, for the preparation of electrochemical sensing and biosensing platform are proposed. Different kinds of important inorganic and organic electroactive compounds (i.e., probe molecule (potassium ferricyanide), free bases of DNA (guanine (G), adenine (A), thymine (T), and cytosine (C)), oxidase/dehydrogenase-related molecules (hydrogen peroxide (H2O2/beta-nicotinamide adenine dinucleotide (NADH)), neurotransmitters (dopamine (DA)), and other biological molecules (ascorbic acid (AA), uric acid (UA), and acetaminophen (APAP)) were employed to study their electrochemical responses at the CR-GO/GC electrode, which shows more favorable electron transfer kinetics than graphite modified glassy carbon (graphite/GC) and glassy carbon (GC) electrodes.
G-Quadruplex-based DNAzyme as a sensing platform for ultrasensitive colorimetric potassium detection
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We report a sensitively amplified electrochemical aptasensor using adenosine triphosphate (ATP) as a model. ATP is a multifunctional nucleotide thatis most important as a "molecular currency" of intracellular energy transfer. In the sensing process, duplexes consisting of partly complementary strand (PCS1), ATP aptamer (ABA) and another partly complementary strand (PCS2) were immobilized onto Au electrode through the 5'-HS on the PCS1. Meanwhile, PCS2 was grafted with the Au nanoparticles (AuNPs) to amplify the detection signals. In the absence of ATP, probe methylene blue (MB) bound to the DNA duplexes and also bound to guanine bases specifically to produce a strong differential pulse voltammetry (DPV) signal. But when ATP exists, the ABA-PCS2 or ABA-PCS1 part duplexes might be destroyed, which decreased the amount of MB on the electrode and led to obviously decreased DPV signal.