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《Information Systems》2005,30(2):89-118
Business rules are the basis of any organization. From an information systems perspective, these business rules function as constraints on a database helping ensure that the structure and content of the real world—sometimes referred to as miniworld—is accurately incorporated into the database. It is important to elicit these rules during the analysis and design stage, since the captured rules are the basis for subsequent development of a business constraints repository. We present a taxonomy for set-based business rules, and describe an overarching framework for modeling rules that constrain the cardinality of sets. The proposed framework results in various types constraints, i.e., attribute, class, participation, projection, co-occurrence, appearance and overlapping, on a semantic model that supports abstractions like classification, generalization/specialization, aggregation and association. We formally define the syntax of our proposed framework in Backus-Naur Form and explicate the semantics using first-order logic. We describe partial ordering in the constraints and define the concept of metaconstraints, which can be used for automatic constraint consistency checking during the design stage itself. We demonstrate the practicality of our approach with a case study and show how our approach to modeling business rules seamlessly integrates into existing database design methodology. Via our proposed framework, we show how explicitly capturing data semantics will help bridge the semantic gap between the real world and its representation in an information system. 相似文献
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The paper describes a Computer Aided Software Engineering (CASE) tool to support conceptual database modelling. One popular approach for conceptual database modelling is use of the Entity-Relationship (ER) model. The paper proposes the use of an Enhanced Entity-Relationship (EER) model for conceptual database modelling. This Enhanced Entity-Relationship model extends the Entity-Relationship model by incorporating the generalization/specialization, aggregation and categorization abstractions. The CASE tool, which is based on the Enhanced Entity-Relationship model, is known as the Enhanced Entity-Relationship Diagrammer (EERD). In addition, the CASE tool supports direct visual query and update based on the EERM. 相似文献
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Conceptual and logical database modelling are difficult tasks for designers, and the potential for committing and correcting errors is significant. This paper reports on two laboratory experiments that investigated the underlying causes of errors committed by novice designers engaged in conceptual database modelling tasks. These causes can be traced to combinatorial complexity of the task, biases resulting from misapplication of heuristics, and incomplete knowledge about database design. The most common error was that subjects translated their initial understanding of the application into final database structures and did not consider alternative hypotheses and solutions. The paper includes recommendations to reduce the occurrence of errors. 相似文献
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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). 相似文献
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基于数据库划分的关联规则算法 总被引:1,自引:0,他引:1
关联规则是数据挖掘的一个重要研究方向.分析了FP算法的优缺点,提出了一种基于数据库划分的算法PFp算法,从理论上证明了该算法的正确性.该方法将事务数据库划分为子事务数据库,在子事务数据库中挖掘局部频繁项集,并入到全局频繁项集中,采用连接和剪枝策略有效挖掘出局部不频繁但全局频繁的频繁项集.实验结果表明,该算法比FP算法更加有效. 相似文献
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A conceptual approach for the die structure design 总被引:3,自引:0,他引:3
A large number of decisions are made during the conceptual design stage which is characterized by a lack of complete geometric information. While existing CAD systems supporting the geometric aspects of design have had little impact at the conceptual design stage. To support the conceptual die design and the top–down design process, a new concept called conceptual assembly modeling framework (CAMF) is presented in this paper. Firstly, the framework employs the zigzag function-symbol mapping to implement the function design of the die. From the easily understood analytical results of the function-symbol mapping matrix, the designer can evaluate the quality of a proposed die concept. Secondly, a new method—logic assembly modeling is proposed using logic components in this framework to satisfy the characteristic of the conceptual die design. Representing shapes and spatial relations in logic can provide a natural, intuitive method of developing complete computer systems for reasoning about die construction design at the conceptual stage. The logic assembly which consists of logic components is an innovative representation that provides a natural link between the function design of the die and the detailed geometric design. 相似文献
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This paper presents a working decision support system for use in the physical design of a database. Physical database design, a structured decision problem, lends itself to a decision support approach because closed form algorithms are computationally infeasible. The paper describes the physical database design problem, presents an overview of a software system for use in solving this problem, and evaluates the use of the system in solving a sample problem. 相似文献
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基于规模约简和多支持度的关联规则挖掘 总被引:1,自引:0,他引:1
关联规则挖掘的经典算法是Apriori算法,但是存在两大突出的问题,即多次扫描事务数据库和使用单一的支持度,导致了由于事务数据库的规模而增加搜索时间和产生冗余规则或有效规则被丢弃。以往的改进算法只从其中一方面进行考虑。因此同时考虑存在问题,给出了一种基于规模约简和多支持度的关联规则挖掘算法。分析和试验显示在效率上有提高。 相似文献
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This paper explores the concepts of concurrency in design and develops an approach that involves reliability and other functional perspectives at the conceptual design stage. The paper uses graph theory to represent a product and define the relationships between its components. It employs the graph-theory concepts of the “tree” and the “forest” to represent a functional design artefact and idle condition, respectively.
The approach presented in the paper provides a more refined visualisation of the energy flow and is applicable to numerous designs including sliding gears, clutches, overrunning clutches and flywheels, amongst others. It can be used to concurrently modify the design taking into consideration various constraints, e.g. expected mechanical failures and cost considerations. A case study is presented to illustrate the benefits of the approach discussed in the paper. 相似文献
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Loan T.T. Nguyen Bay Vo Tzung-Pei Hong Hoang Chi Thanh 《Expert systems with applications》2012,39(13):11357-11366
Classification plays an important role in decision support systems. A lot of methods for mining classification rules have been developed in recent years, such as C4.5 and ILA. These methods are, however, based on heuristics and greedy approaches to generate rule sets that are either too general or too overfitting for a given dataset. They thus often yield high error ratios. Recently, a new method for classification from data mining, called the Classification Based on Associations (CBA), has been proposed for mining class-association rules (CARs). This method has more advantages than the heuristic and greedy methods in that the former could easily remove noise, and the accuracy is thus higher. It can additionally generate a rule set that is more complete than C4.5 and ILA. One of the weaknesses of mining CARs is that it consumes more time than C4.5 and ILA because it has to check its generated rule with the set of the other rules. We thus propose an efficient pruning approach to build a classifier quickly. Firstly, we design a lattice structure and propose an algorithm for fast mining CARs using this lattice. Secondly, we develop some theorems and propose an algorithm for pruning redundant rules quickly based on these theorems. Experimental results also show that the proposed approach is more efficient than those used previously. 相似文献
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In mechanical system design, the Integrated Computer Aided Design (ICAD) technology has evolved into a new generation of design techniques. It also paves the way for implementing Computer Integrated Manufacturing (CIM) systems. However, the key issue to accomplish the objective in ICAD is the conceptual design automation. Conceptual design is a creative activity and an important decision making during overall product design to reduce energy consumption, to increase raw materials utilization, to obtain more profits, to reduce environmental effects of effluents, and to ensure flexibility, operability, controllability, and safety of manufacturing processes. Therefore, the quality of conceptual design determines the final quality of products and profit of plants. In this article, we first introduce the fundamentals and characteristics of conceptual design. Then, a general problem-solving strategy and methodology to implement conceptual design automation are proposed. an Integrated Distributed Intelligent Design Environment (IDIDE) for developing conceptual design expert systems is presented. Fundamental principles, system organization, and implementation techniques are discussed. Finally, an application case for wheel loader design is studied. © 1995 John Wiley & Sons, Inc. 相似文献
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基于关系数据库的关联规则的形式化开采 总被引:1,自引:0,他引:1
从研究关联规则概念入手,探讨了项目、项目集合和交易数据库等概念在关系数据库中的具体含义,提出了一种全面的、易于理解和使用的关联规则形式化描述方法,并给出了开采关系型数据库中关联规则的一般过程,这为关系型数据库中关联规则开采系统的设计奠定了基础,对系统设计者有一定的指导意义。 相似文献
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A multi-level conceptual data reduction approach based on the Lukasiewicz implication 总被引:1,自引:0,他引:1
Starting from fuzzy binary data represented as tables in the fuzzy relational database, in this paper, we use fuzzy formal concept analysis to reduce the tables size to only keep the minimal rows in each table, without losing knowledge (i.e., association rules extracted from reduced databases are identical at given precision level). More specifically, we develop a fuzzy extension of a previously proposed algorithm for crisp data reduction without loss of knowledge. The fuzzy Galois connection based on the Lukasiewicz implication is mainly used in the definition of the closure operator according to a precision level, which makes data reduction sensitive to the variation of this precision level. 相似文献
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Design data are assigned in geometric and non-geometric form in order to meet design requirements. These data and information must be encapsulated in a data structure that has significance for design applications in each design process phase. The main goal of this research is to find design data groups that represent each mechanical design phase, which will be called phase's design signature. In addition, current data should be an evolution of the geometric and non-geometric information of the previous design phase. In this paper, the purpose is to identify and model a set of design features that encapsulate the design data and their transformations which occurred during the mechanical design phases. This database must capture the designer's intents that can be modeled and implemented using feature-based model in the conventional CAD systems, object-oriented modeling, and Java classes. 相似文献
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传统的中英文网站开发采用两套代码两个数据库或者一套代码两套资源文件的开发模式,在软硬件开销、代码与信息分离和系统的维护性方面均存在不同程度的缺陷。针对这一问题.把页面设计与数据库设计结合起来,利用编程技术,用一套代码一个数据库实现中英文双语网站的开发,以提高开发及维护效率,降低软件成本。 相似文献
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一种基于Apriori的动态关联规则挖掘方法 总被引:2,自引:0,他引:2
文章介绍了一种动态关联规则的挖掘方法,该方法的核心思想是仅使用更新的事务和前面阶段的挖掘结果,用Apriori类算法作为局部过程来产生频集,并给出了具体的动态挖掘算法。 相似文献
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This paper reports on the application of the DATAID-1 database design methodology, which has been described in the associated paper[1]. The case study concerns the design of a database information system and has been completely developed, from the requirements collection and analysis phase to the physical design phase, to illustrate the main features of the methodology. 相似文献