一种模糊XML模型的概念设计方法

XML(Extensible Markup Language)已经成为Web上数据表示与交换的标准,而信息的不精确性和不确定性又广泛存在于现实世界应用中。虽然模糊信息在关系数据库框架下已经被广泛讨论,但是传统的关系数据库模型及其模糊扩展形式不能满足表示和处理Web上复杂模糊对象的需要。基于可能性分布,研究在XML模型和IFO数 据模型—一种概念数据模型中进行模糊信息建模,给出把模糊IFO数据模型映射成模糊XML DTD模型的形式化方法。     

电信管理元模型及数据模型的研究

分析了电信管理信息集成化的问题，将元对象机制引入到电信管理中，提出了电信管理元模型和数据模型的概念。在元模型中，完成了对电信管理数据的抽象，定义了元数据类和元关系。在数据模型中划分不同的维度，定义了核心数据类，实现了信息的完备定义。通过建立实际系统数据模型，验证了此建模方法的有效性。     

基于UML类图的模糊时空数据建模

模糊性广泛存在于时空应用领域,现有的时空数据模型缺乏描述和表达模糊时空对象内在机制和语义关系的能力。通过研究模糊时空数据语义,给出了模糊时空数据模型的形式化定义,在此基础上对UML类图进行扩展,提出一种模糊时空UML数据模型,并用例子说明本文所提模糊时空数据模型的可用性。     

特定领域的数据参考模型建模方法研究

针对领域内数据实体变化频繁,复用性低的问题,提出了特定领域数据参考模型的概念,它基于概念模型的形式,对领域内的通用数据模型进行说明和描述,成为领域内应用系统数据建模的基础.给出了领域数据参考模型的体系架构,它对整个模型进行了纵横向的划分以便作为不同程度的复用的基础.在概念模型构建时,提出了数据模型构建步骤,并引入了"维度","维度层次"和"事实"3个数据仓库中的概念,扩充了ER图中的属性定义,为构建稳定可复用的领域实体提供了有效的途径.     

基于XPath数据模型的双时态扩展

XML作为Web上新的数据发布语言,将成为Web下一代"数据表达"和"数据交换"的统一标准.然而XML文档很少是静止的,它经常会被修改,引入"时态表达"后时态XML文档能够记录一系列的修改痕迹,提供了一种高效可行的XML版本管理方案.另一方面XML表达时态信息比关系模型更自然,时态数据库的研究人员开始将部分焦点转向研究如何利用XML实现时态信息处理.提出了一个双时态XML数据模型并给出了形式化定义,该模型将一个双时态XML文档建模成一个带有"双时态元素"边标记的有向树形图.还讨论了该模型映射到双时态XML文档的两种映射方法;并采用扩展DOM API的方法实现了模型以及映射.最后通过实验对比了扩展DOM实现模型和不扩展DOM实现模型两种实现方法,两种模型映射到双时态XML文档的映射方法.     

基于UML扩展的数据仓库多维数据PIM建模

针对数据仓库多维数据PIM建模问题,对多维数据模型维和事实进行了定义.在UML(Unified Modeling Language)扩展的基础上,提出了与多维模型相关的八个版类,从而可以对数据仓库中PIM模型的各种情况进行图形化描述.最后基于某钢铁企业采购系统的采购价格差异分析主题进行了建模.     

基于Vague集的时态数据库

为了更加精确地表示模糊信息,数据库的模糊属性采用Vague集来表示.基于Vague集的数据库模型与现有模糊关系数据模型相比,有更强的模糊表达能力,数据库中的每一数据及元组均可分别从真、假隶属度及未知程度三个侧面予以体现.在Vague数据库模型的基础上进行了扩展,提出了基于Vague集的时态数据库,为进一步研究Vague时态数据库的数据模型、数据理论等相关问题打下了基础.     

虚拟环境中装配设计语义的表达、传递与转化研究

研究了虚拟环境产品装配建模过程中装配语义的表达、装配语义与装配约束的转化技术,提出了采用语义－约束图对装配设计语义与约束进行维护。通过语义－约束图可以从语义层次和约束层次对产品装配模型进行编辑和维护。提出了采用模糊参量表达和处理产品装配设计中的模糊语义。基于模糊参量的语义表达不仅为设计信息输入提供了更大的自由度,而且扩展了计算机对模糊信息的处理能力,有利于产品设计意图的维护。通过产品装配信息从抽象到具体、从模糊到精确的转化,实现了虚拟装配设计系统对抽象、模糊设计信息的表达、传递与处理。     

网络化自动测试系统的数据模型研究

依据网络化自动测试系统(NATS)存储和查询功能对数据模型的要求,比较扩展关系数据模型、语义数据模型和面向对象数据模型等多媒体数据模型实现方式的优缺点,提出数据库设计的基本框架为静态数据信息采用关系型数据模型,非结构化的多媒体数据信息采用对象-关系模型与文件系统结合的方式,并完成NATS的总体设计。实验结果证明了该框架的有效性。     

模糊XML DTD到UML数据模型的转换

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,而XML已经成为Web上信息表示和交换的标准.基于可能性分布理论,识别出XML文档多粒度数据模糊性,提出了模糊XML和UML数据模型,在此基础上给出了从模糊XML模型到模糊UML类图的形式化转化方法.     

A formal approach for graphically building fuzzy XML model

eXtensible Markup Language (XML) has been the de facto standard of data representation and exchange over the Web. In addition, imprecise and uncertain data are inherent in the real world. Although fuzzy data have been extensively investigated in the context of the relational model, the classical relational database model and its fuzzy extension to date do not satisfy the need of modeling complex objects with imprecision and uncertainty on the Web. On the basis of possibility theory, this paper concentrates on fuzzy information modeling in the fuzzy XML model and the fuzzy IFO model. In particular, the formal approach to mapping a fuzzy IFO model to a fuzzy document-type definition model is developed.     

Modeling and Management of Fuzzy Information in Multimedia Database Applications

In this paper, we firstly present a conceptual data model for multimedia database applications based on ExIFO₂ model. The ExIFO₂ data model is chosen as the conceptual model since it handles complex objects along with their uncertain and imprecise properties. We enhanced this conceptual model in order to meet the multimedia data requirements. In addition to uncertain and imprecise information, we present a way of handling relationships among objects of multimedia database applications. Events that might be extracted from video or audio are also considered in this study. Secondly, the conceptual model is mapped to a logical model, which the fuzzy object-oriented data (FOOD) model is chosen, for storing and manipulating the multimedia objects. This mapping is done in a way that it preserves most of the information represented at the conceptual level. Finally, in this study videos of football (soccer) games is selected as the multimedia database application to show how we handle crisp and fuzzy querying and retrieval of fuzzy and crisp data from the database. A program has been developed to draw ExIFO₂ schemas and to map the schema to FOOD code automatically.     

Universal triple I fuzzy reasoning algorithm of function model based on quotient space

Aiming at the deficiencies of analysis capacity from different levels and fuzzy treating method in product function modeling of conceptual design,the theory of quotient space and universal triple I fuzzy reasoning method are introduced,and then the function modeling algorithm based on the universal triple I fuzzy reasoning method is proposed.Firstly,the product function granular model based on the quotient space theory is built,with its function granular representation and computing rules defined at the same time.Secondly,in order to quickly achieve function granular model from function requirement,the function modeling method based on universal triple I fuzzy reasoning is put forward.Within the fuzzy reasoning of universal triple I method,the small-distance-activating method is proposed as the kernel of fuzzy reasoning;how to change function requirements to fuzzy ones,fuzzy computing methods,and strategy of fuzzy reasoning are respectively investigated as well;the function modeling algorithm based on the universal triple I fuzzy reasoning method is achieved.Lastly,the validity of the function granular model and function modeling algorithm is validated.Through our method,the reasonable function granular model can be quickly achieved from function requirements,and the fuzzy character of conceptual design can be well handled,which greatly improves conceptual design.     

A systematic decision making approach for product conceptual design based on fuzzy morphological matrix

Conceptual design plays an important role in development of new products and redesign of existing products. Morphological matrix is a popular tool for conceptual design. Although the morphological-matrix based conceptual design approaches are effective for generation of conceptual schemes, quantitative evaluation to each of the function solution principle is seldom considered, thus leading to the difficulty to identify the optimal conceptual design by combining these function solution principles. In addition, the uncertainties due to the subjective evaluations from engineers and customers in early design stage are not considered in these morphological-matrix based conceptual design approaches. To solve these problems, a systematic decision making approach is developed in this research for product conceptual design based on fuzzy morphological matrix to quantitatively evaluate function solution principles using knowledge and preferences of engineers and customers with subjective uncertainties. In this research, the morphological matrix is quantified by associating the properties of function solution principles with the information of customer preferences and product failures. Customer preferences for different function solution principles are obtained from multiple customers using fuzzy pairwise comparison (FPC). The fuzzy customer preference degree of each solution principle is then calculated by fuzzy logarithmic least square method (FLLSM). In addition, the product failure data are used to improve product reliability through fuzzy failure mode effects analysis (FMEA). Unlike the traditional FMEA, the causality relationships among failure modes of solution principles are analyzed to use failure information more effectively through constructing a directed failure causality relationship diagram (DFCRD). A fuzzy multi-objective optimization model is also developed to solve the conceptual design problem. The effectiveness of this new approach is demonstrated using a real-world application for conceptual design of a horizontal directional drilling machine (HDDM).     

演员模型：一种多媒体数据表达模型

本文提出一种多媒体数据表达模型：演员模型，该模型建立在多媒体数据库概念模型基础之上，基于库所—时间Ｐｅｔｒｉ网，描述多媒体对象之间的时态关系，同时引入与变迁相关联的场景表达式，描述多媒体对象之间的空间关系，从而模拟多媒体数据的时空编组，文中形式化地定义了演员模型的抽象模型和实现模型，提出多媒体对象的表达算法以及多媒体数据库的查询模型．     

支持非覆盖维的扩展多维数据模型

非覆盖维等复杂结构维的处理一直都是数据仓库领域的难题,本文在详细分析非覆盖维特性的基础上,提出了一个扩展的多维数据模型,改变了传统的级别间的映射关系的定义方式,定义了从父级别到子级别分区的映射关系,从而实现了对非覆盖维和非平衡维的支持,并能够完整地表达各种复杂维层次结构语义.同时,基于DAG图描述的维层次结构,定义了基于该多维模型的立方体代数和OLAP操作.将多维数据库概念模型中的维与度量的转换操作引入到OLAP操作集合中,使其支持复杂维的转化操作,进而丰富和增强基于该模型的OLAP系统的分析能力.     

一种基于知识的多层概念化数据查询方法

近年来,越来越多的数据库查询研究工作开始致力于对模糊查询条件的概念化处理,称之为概念化查询.运用基于知识的数据查询方法可以实现这类查询,基本的方法是根据领域知识将用户的模糊概念转换成标准的SQL语句,实现概念化查询.但是,如果查询条件中包含了更高层次及多层次的模糊概念,则其概念转换非常复杂,查询的效率将受到严重影响.为了提高多层次数据查询的效率,以村镇住宅建筑产品查询为例,提出一种基于知识的多层概念化数据查询方法.首先需要建立描述模糊概念的知识库;然后,生成多层次的概念化数据,在概念化数据上实现基于知识库的多层数据查询处理.并采用人工数据集进行了实验分析,实验结果表明,在高层和多层概念化查询中,本文提出的方法与基本的方法相比查询效率至少提高40%.基于知识的多层概念化查询将为我国村镇住宅建筑产品查询提供高效的处理手段,能够满足不同知识水平用户的查询需求,具有较高的实用价值.     

基于双排序原理的先进先出数据核销高速通用算法

本文按照软件中台的思想,设计了一个针对先进先出(First-In First-Out,FIFO)[1]数据核销的通用实现框架及其对应的入库数据模型、消费数据模型和匹配核销模型。同时,设计了基于双排序原理的先进先出数据核销高速实现方法。该方法按照匹配规则先对数据进行排序,然后对两个有序队列进行单循环匹配查找,避免了传统先进先出实现中的双循环操作,可以大幅度提高运算性能,大幅度节省CPU开销和存储开销,实现超大数据量的快速匹配,可以支持两个亿级数据库的快速先进先出匹配。