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1.
信息技术的发展使得传统的 XML文档构建方式越来越难以满足当前对于构建 XML文档的要求。介绍了一种利用 UML设计 XML文档及其 Schema的方法 ,并给出了一个具体的应用实例。  相似文献   

2.
基于XML和Agent联邦的工作流建模方法   总被引:4,自引:2,他引:4  
介绍一种基于XML和Agent联邦的工作流建模方法,目的在于建立分布式环境下灵活的,动态的工作流管理过程。该方法将工作流管理系统组织成一个可能嵌套的Agent联邦,将工作流定义为一个由Agent联邦协同完成的活动集合。面向活动分担的联合意向是Agent进行工作流规划的依据与手段,它成功地解决了工作流过程分解的静态性与工作流过程运行的动态性之间的矛盾。文中方法采用的过程建模语言是建立在XML的基础上,与传统的过程建模语言相比,它具有更强的可操作性与可扩展性。最后介绍了工作流建模环境以及利用该环境进行工作流建模的过程与步骤。  相似文献   

3.
基于UML的XML建模方法   总被引:7,自引:0,他引:7  
张志  赵文耘  李川 《计算机工程》2003,29(8):195-196,F003
针对由业务模型直接定义XML Schema存在较多的困难,提出了一种把UML技术用于XML Schema建模的方法。该方法通过领域建模定义了3层模型,即概念层模型、逻辑层模型和实现层模型,分别对应于业务模型的分析、设计及实现阶段,并对各层模型之间的转换方法进行了有效的探讨。  相似文献   

4.
基于关系数据库映射的模糊数据XML建模   总被引:1,自引:0,他引:1  
严丽  马宗民  刘健  张富 《计算机学报》2011,34(2):291-303
在很多现实世界应用中存在着大量的不精确性和不确定性信息,正是由于这个原因,基于各类数据模型的模糊数据建模的研究已经广泛展开.当前互联网上存在大量的电子数据资源,XML已经成为Web上信息表示和交换的标准,但现有的XML研究成果难以满足Web环境下智能化数据管理的需求.文中从数据库信息建模的角度入手,基于模糊集和可能性分...  相似文献   

5.
介绍了XML的基本语法,包括标记语法、文档结构、建立XML数据类型的方法、XML数据的粒度的概念,类型化和非类型化xml数据应用探讨,XML类型数据各种索引的创建方法及准则。初步探讨如何对不同的数据进行建模。  相似文献   

6.
研究基于ASP模式的虚拟企业建模工具的需求和应用前景。通过应用服务提供商(ASP)模式的概念,提出一种基于ASP模式的虚拟企业建模工具框架的设计方案。将体系结构分为功能结构、逻辑层次和Portal结构三方面加以设计。最后总结此方案,并对新系统将来向协同化、集成化、纯ASP化发展作了展望。  相似文献   

7.
This paper investigates the possibility of performing automated reasoning in probabilistic knowledge bases when probabilities are expressed by means of linguistic quantifiers. Data are expressed in terms of ill-known conditional probabilities represented by linguistic terms. Each linguistic term is expressed as a prescribed interval of proportions. Then instead of propagating numbers, qualitative terms are propagated in accordance with the numerical interpretation of these terms. The quantified syllogism, modeling the chaining of probabilistic rules, is studied in this context. It is shown that a qualitative counterpart of this syllogism makes sense and is fairly independent of the thresholds defining the linguistically meaningful intervals, provided that these threshold values remain in accordance with the intuition. The inference power is less than a full-fledged probabilistic constraint propagation device but corresponds better to what could be thought of as commonsense probabilistic reasoning. Suggestions that may improve the inferencing power in the qualitative setting are proposed.This paper is an extended and revised version of a paper entitled A Symbolic Approach to Reasoning with Linguistic Quantifiers inProc. 8th Conf. Uncertainty in Artificial Intelligence Dubois, D., Wellman, M.P., D'Ambrosio, B., and Smets, Ph. (Eds.), Morgan Kaufmann, pp. 74–82, 1992.  相似文献   

8.
语义对象模型是把语义看作基本出发点,用来文档化用户需求并建立数据模型的。利用语义对象模型来获得XML Schema,或将语义对象模型作为关系数据模型向XML Schema转换的中介,有利于尽可能多地保留数据的语义信息。文章提出了利用语义对象的XML Schema数据建模的一些基本规则和方法。  相似文献   

9.
10.
Stochastic dominance, which is based on the comparison of distribution functions, is one of the most popular preference measures. However, its use is limited to the case where the goal is to compare pairs of distribution functions, whereas in many cases it is interesting to compare sets of distribution functions: this may be the case for instance when the available information does not allow to fully elicitate the probability distributions of the random variables. To deal with these situations, a number of generalisations of the notion of stochastic dominance are proposed; their connection with an equivalent p-box representation of the sets of distribution functions is studied; a number of particular cases, such as sets of distributions associated to possibility measures, are investigated; and an application to the comparison of the Lorenz curves of countries within the same region is presented.  相似文献   

11.
XML Schema Modeling through UML Class Diagram   总被引:1,自引:0,他引:1  
A three-step XML Schema modeling method is presented, namely first establishing a diagram of conceptual modeling, then transforming it to UML class diagram and finally mapping it to XML Schema. A case study of handling furniture design data is given to illustrate the detail of conversion process.  相似文献   

12.
本文针对当前软件设计中非功能需求描述不清楚、难以实现等问题,对软件非功能需求建模方法进行了研究,提出了一个基于XML的软件非功能需求建模方法,构建了一个软件非功能需求元模型,该模型主要包括属性、约束和实现方法三个数据单元.在此基础上,利用XML Schema定义了软件非功能需求的数据模型结构,以一个通信系统的非功能需求建模为例说明了本模型的建模过程和方法,结果表明,该建模方法有助于设计人员对软件非功能需求进行清楚的定义.  相似文献   

13.
The important challenge of evaluating XPath queries over XML streams has sparked much interest in the past few years. A number of algorithms have been proposed, supporting wider fragments of the query language, and exhibiting better performance and memory utilization. Nevertheless, all the algorithms known to date use a prohibitively large amount of memory for certain types of queries. A natural question then is whether this memory bottleneck is inherent or just an artifact of the proposed algorithms.In this paper we initiate the first systematic and theoretical study of lower bounds on the amount of memory required to evaluate XPath queries over XML streams. We present a general lower bound technique, which given a query, specifies the minimum amount of memory that any algorithm evaluating the query on a stream would need to incur. The lower bounds are stated in terms of new graph-theoretic properties of queries. The proofs are based on tools from communication complexity.We then exploit insights learned from the lower bounds to obtain a new algorithm for XPath evaluation on streams. The algorithm uses space close to the optimum. Our algorithm deviates from the standard paradigm of using automata or transducers, thereby avoiding the need to store large transition tables.  相似文献   

14.
Information is said to be bipolar when it has a positive and a negative part. The problem of representing and processing such bipolar information has recently received a lot of attention in uncertainty theories. In this paper, we are concerned with the representation of asymmetric bipolarity, i.e., with situations where positive and negative information are unrelated and processed in parallel. In this latter case, positive information consists of observations of experiment results, showing what values are possible, whereas negative information consists of constraints (e.g., provided by an expert), restricting the range of possible variable values. Up to now, there are no proposition as to how such bipolar information can be treated in the framework of imprecise probability theory, i.e., when information is represented by convex sets of probabilities. In this paper, we propose the basis of such a framework and provide some illustrative examples. © 2011 Wiley Periodicals, Inc.  相似文献   

15.
In this paper we consider the maximum entropy principle with imprecise side-conditions, where the imprecise side-conditions are modeled as fuzzy sets. Our solution produces fuzzy discrete probability distributions and fuzzy probability density functions.  相似文献   

16.
《Computer Networks》2007,51(16):4634-4654
In recent years, both the number and capabilities of mobile devices have increased rapidly to the point where the mobile world is becoming a significant part of the Internet. Another recent trend is the increase in XML use for communication between applications. However, the mobile world has been reluctant to adopt XML due to its verbosity and processing needs.We consider here the problem of providing an XML-based messaging system for mobile devices. We analyze the requirements that the environment places on such a system and elaborate on these requirements by concentrating on three components that seem most amenable to improvements, namely XML processing interfaces, XML serialization, and message transfer protocols. In tandem with the analysis we also present the design and implementation of our messaging system that addresses these requirements.Our experimentation of this system is extensive and performed completely on real devices and real wireless networks. Based on our implementation and experimentation we conclude that there is potential for improvement in XML messaging. The largest gains are achieved by using an asynchronous programming style and by using a compact serialization format. The improvements are also individually integratable into existing systems.  相似文献   

17.
Sensor network localization with imprecise distances   总被引:1,自引:0,他引:1  
An approach to formulate geometric relations among distances between nodes as equality constraints is introduced in this paper to study the localization problem with imprecise distance information in sensor networks. These constraints can be further used to formulate optimization problems for distance estimation. The optimization solutions correspond to a set of distances that are consistent with the fact that sensor nodes live in the same plane or 3D space as the anchor nodes. These techniques serve as the foundation for most of the existing localization algorithms that depend on the sensors’ distances to anchors to compute each sensor's location.  相似文献   

18.
A robust minimax approach for optimal investment decisions with imprecise return forecasts and risk estimations in financial portfolio management is considered. Single-period and multi-period mean-variance optimization models are extended to worst-case design with multiple rival risk estimations and return forecasts. In multi-period stochastic formulation of classical mean-variance portfolio optimization problem, an investor makes an investment decision based on expectations and/or scenarios up to some intermediate times prior to the horizon and, consequently, rebalances or restructures the portfolio. Multi-period portfolio optimization entails the construction of a scenario tree representing a discretized estimate of uncertainties and associated probabilities in future stages. It is well known that return forecasts and risk estimations are inherently inaccurate and there are different rival estimates, or scenario trees. Robust optimization models are presented and imprecise nature of moment forecasts to reduce the risk of making a decision based on the wrong scenario is addressed. The worst-case performance is guaranteed in view of all rival risk and return scenarios and will only improve when any scenario other than the worst-case is realized. The ex-ante performance of minimax models is tested using historical data and backtesting results are presented.  相似文献   

19.
基于XML建模的研究及其在CAPP系统中的应用   总被引:2,自引:0,他引:2  
XML是数据访问领域的最新技术,本文分析了基于XML建立数据模型的必然趋势,讲述了基于XML进行模型设计的通用过程。详细分析了CAPP系统中的信息,在此基础上,讲述了基于XML建立CAPP系统信息模型的方法,并且对于零件特征信息进行了建模示例。  相似文献   

20.
基于XML的参数化虚拟场景建模技术   总被引:2,自引:0,他引:2       下载免费PDF全文
针对VRML虚拟场景建模可定制性差和开发效率低的缺陷,提出一种基于XML的参数化虚拟场景建模技术,增强了VRML 场景建模的可定制性,提高了开发效率,并对大场景采用区域划分的方法,提高了大场景的绘制速度,在虚拟城市的构建项目中得到了较好的应用。  相似文献   

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