基于偏好信息的案例检索算法

案例推理方法建立在“相似问题具有相似解”的基础上,能否从案例库中检索出与新问题“最相似”的案例是案例推理方法成功的关键因素之一。该文提出一种改进的检索方法,在原始最近相邻算法基础上,用专家对新问题案例与历史案例属性差异的效用评价替代原始的属性差异值来衡量专家对属性差异的敏感程度。引入变异系数来标度新问题案例与历史案例的属性差异的分布情况,从而保证检索出的最相似案例具有较高的属性差异的均衡性。通过具体案例检索实例分析,验证了该方法的有效性。     

Similarity and metrics in case‐based reasoning

Similarity is a core concept in case‐based reasoning (CBR), because case base building, case retrieval, and even case adaptation all use similarity or similarity‐based reasoning. However, there is some confusion using similarity, similarity measures, and similarity metrics in CBR, in particular in domain‐dependent CBR systems. This article attempts to resolve this confusion by providing a unified framework for similarity, similarity relations, similarity measures, and similarity metrics, and their relationship. This article also extends some of the well‐known results in the theory of relations to similarity metrics. It appears that such extension may be of significance in case base building and case retrieval in CBR, as well as in various applied areas in which similarity plays an important role in system behavior. © 2002 Wiley Periodicals, Inc.     

Abductive case‐based reasoning

This article introduces abductive case‐based reasoning (CBR) and attempts to show that abductive CBR and deductive CBR can be integrated in clinical process and problem solving. Then it provides a unified formalization for integration of abduction, abductive CBR, deduction, and deductive CBR. This article also investigates abductive case retrieval and deductive case retrieval using similarity relations, fuzzy similarity relations, and similarity metrics. The proposed approach demonstrates that the integration of deductive CBR and abductive CBR is of practical significance in problem solving such as system diagnosis and analysis, and will facilitate research of abductive CBR and deductive CBR. © 2005 Wiley Periodicals, Inc. Int J Int Syst 20: 957–983, 2005.     

基于实体的相似性连接算法

按照元组描述的实体对其进行组织和查询处理,是一种管理劣质数据的有效方法.考虑到同一个实体的同一属性存在多个描述的值,因此,基于实体的数据库上的连接是支持多个值的相似性连接.与字符串的相似性连接相比较,实体的相似性连接在数据清洗、信息集成、模糊关键字查询、诈骗检测和文本聚集等领域有着更好的应用效果.通过建立双层索引结构,提出了实体数据库上相似性连接算法ES-JOIN.同时,该方法适用于解决集合中字符串模糊匹配的相似性连接问题,而传统的集合相似性连接只针对集合中元素精确匹配的情况.为了加速连接,还提出了过滤措施对算法进行优化,进一步给出了优化算法OPT_ES-JOIN.实验验证了ES-JOIN算法和OPT_ES-JOIN算法具有很好的效率和可扩展性.实验结果表明,过滤措施具有很好的过滤效果.     

异质信息环境下基于案例推理的应急决策方法

针对在突发事件应急决策中,信息表述为精确数、区间数、语言术语、直觉模糊数、中智数、梯形模糊中智数等多样性的特点,同时鉴于案例推理方法的简单易用,提出一种异质信息环境下基于案例推理的应急决策方法.首先,引入异质数据的距离及相似度测度,并基于偏差最大化方法计算异质信息属性权重;然后,基于综合相似度测度,采用案例推理的方法从案例库中找到与目标案例相同或者相似的历史案例,从而获得有效的解决当前突发事件的应急预案和处理措施;最后,通过一个应急突发事件案例验证所提出决策方法的可行性和有效性,同时与其他方法相比较验证其优点.     

Ontology-based similarity for product information retrieval

Product development of today is becoming increasingly knowledge intensive. Specifically, design teams face considerable challenges in making effective use of increasing amounts of information. In order to support product information retrieval and reuse, one approach is to use case-based reasoning (CBR) in which problems are solved “by using or adapting solutions to old problems.” In CBR, a case includes both a representation of the problem and a solution to that problem. Case-based reasoning uses similarity measures to identify cases which are more relevant to the problem to be solved. However, most non-numeric similarity measures are based on syntactic grounds, which often fail to produce good matches when confronted with the meaning associated to the words they compare. To overcome this limitation, ontologies can be used to produce similarity measures that are based on semantics. This paper presents an ontology-based approach that can determine the similarity between two classes using feature-based similarity measures that replace features with attributes. The proposed approach is evaluated against other existing similarities. Finally, the effectiveness of the proposed approach is illustrated with a case study on product–service–system design problems.     

Hybrid similarity measure for case retrieval in CBR and its application to emergency response towards gas explosion

Case retrieval is a primary step in case-based reasoning (CBR). It is important to measure the similarity between each historical case and the target case during the case retrieval process. In recent years, some methods for similarity measure with multiple formats of attribute values can be found in the practical CBR applications, but the in-depth study is still lacking. The objective of this paper is to develop a new method for hybrid similarity measure with five formats of attribute values: crisp symbols, crisp numbers, interval numbers, fuzzy linguistic variables and random variables. First, for each format of the attribute values, the calculation formula to measure the attribute similarity is presented. Then, the method for measuring hybrid similarity between each historical case and the target case is given by aggregating attribute similarities using the simple additive weighting method, and the proper historical case(s) can be retrieved according to the obtained hybrid similarities afterwards. Finally, a case study in the field of emergency response towards gas explosion is introduced to illustrate the use of the proposed method.     

针对构件测试本体的语义相似度计算方法

为了提高构件测试信息的检索效率,针对现有本体语义相似度计算方法作用于构件测试本体时容易出现漏检的问题,提出一种结合本体概念和属性的综合语义相似度计算方法。该方法首先结合概念的结构、层次、子代节点个数和祖先节点个数等因素计算概念相似度;然后,结合属性的概念相似度和数据类型相似度计算属性相似度;最后,综合概念相似度和属性相似度计算本体的语义相似度。实验表明该方法可以有效应用于构件测试领域及其他领域的信息检索。     

电子商务智能推荐系统中基于领域本体的案例检索算法

针对传统电子商务推荐算法的不足,提出了综合语义相似度的案例检索算法。算法通过加权平均商品的概念语义相似度、基于类型的属性语义相似度和基于数据类型的属性值相似度,来计算案例的综合相似度,避免了传统推荐算法中计算相似度仅靠属性值,没考虑语义和属性类型的影响造成的效率低、精度差等问题。设计了领域本体协同案例推理的电子商务智能推荐系统架构,通过在领域本体中抽取语义要素对案例进行表示,拓宽了案例求解空间,达到了协助用户检索及完成商品推荐的任务。经实例对比分析该算法有效且精度较高。     

基于混合推理的仿真实验设计方法智能选择

针对仿真实验设计方法众多而在实际应用中难以准确选择的问题,提出一种用于仿真实验设计方法智能选择的混合推理方法.首先,给出了基于混合推理的仿真实验智能化设计流程;然后,针对案例检索策略,将仿真实验设计案例的属性分为三种类型,分别给出其属性差异度量模型及特征值归一化方法,并采用训练后的神经网络模型分配属性权重;进一步,当推荐的案例未能满足给定的相似度阈值时,引入属性优先级的概念,提出了一种基于规则的柔性逐层推理方法;在此基础上,设计了案例库和规则库;最后,通过实验验证了所提出方法的有效性.     

Similarity assessment and efficient retrieval of semantic workflows

In the recent years, the use of workflows has significantly expanded from its original domain of business processes towards new areas. The increasing demand for individual and more flexible workflows asks for new methods that support domain experts to create, monitor, and adapt workflows. The emergent field of process-oriented case-based reasoning addresses this problem by proposing methods for reasoning with workflows based on experience. New workflows can be constructed by reuse of already available similar workflows from a repository. Hence, methods for the similarity assessment of workflows and for the efficient retrieval of similar workflows from a repository are of core importance. To this end, we describe a new generic model for representing workflows as semantically labeled graphs, together with a related model for knowledge intensive similarity measures. Further, new algorithms for workflow similarity computation, based on A⁎ search are described. A new retrieval algorithm is introduced that goes beyond traditional sequential retrieval for graphs, interweaving similarity computation with case selection. We describe the application of this model and several experimental evaluations of the algorithms in the domain of scientific workflows and in the domain of business workflows, thereby showing its broad applicability.     

Reasoning about pictures and similarity retrieval for image information systems based on SK-set knowledge representation

Spatial reasoning and similarity retrieval are two important functions of any image information system. Good spatial knowledge representation for images is necessary to adequately support these two functions. In this paper, we propose a new spatial knowledge representation, called the SK-set based on morphological skeleton theories. Spatial reasoning algorithms which achieve more accurate results by directly analysing skeletons are described. SK-set facilitates browsing and progressive visualization. We also define four new types of similarity measures and propose a similarity retrieval algorithm for performing image retrieval. Moreover, using SK-set as a spatial knowledge representation will reduce the storage space required by an image database significantly.     

From case-based reasoning to traces-based reasoning

CBR is an original AI paradigm based on the adaptation of solutions of past problems in order to solve new similar problems. Hence, a case is a problem with its solution and cases are stored in a case library. The reasoning process follows a cycle that facilitates “learning” from new solved cases. This approach can be also viewed as a lazy learning method when applied for task classification. CBR is applied for various tasks as design, planning, diagnosis, information retrieval, etc. The paper is the occasion to go a step further in reusing past unstructured experience, by considering traces of computer use as experience knowledge containers for situation based problem solving.     

Exploiting domain geometry in analogical route planning

Abstract. Automated route planning consists of using real maps to automatically find good map routes. Two shortcomings to standard methods are (1) that domain information may be lacking, and (2) that a ‘good’ route can be hard to define. Most on-line map representations do not include information that may be relevant for the purpose of generating good realistic routes, such as traffic patterns, construction, and one-way streets. The notion of a good route is dependent not only on geometry (shortest path),but also on a variety of other factors, such as the day and time, weather conditions,and perhaps most importantly,user-dependent preferences. These features can be learned by evaluating real-world execution experience. These difficulties motivate our work on applying analogical reasoning to route planning. Analogical reasoning is a method of using past experience to improve problem solving performance in similar new situations.Our approach consists of the accumulation and reuse of previously traversed routes. We exploit the geometric characteristics of the map domain in the storage, retrieval, and reuse phases of the analogical reasoning process. Our route planning method retrieves and reuses multiple past routing cases that collectively form a good basis for generating a new routing plan. To find a good set of past routes, we have designed a similarity metric that takes into account the geometric and continuous-valued characteristics of a city map. The metric evaluates its own performance and uses execution experience to improve its prediction of case similarity, adaptability and executability. The planner uses a replay mechanism to produce a route plan based on analogy with past routes retrieved by the similarity metric. We use illustrative examples and show some empirical results from a detailed on-line map of the city of Pittsburgh, containing over 18,000 intersections and 25,000 street segments.     

融合事故表征和CBR的特种设备事故预测研究

为了更好地预测特种设备事故,提出了融合事故表征和CBR（case-based reasoning）的特种设备事故预测研究。详细说明了面向全类特种设备的通用型事故表征技术,包括事故表征信息的结构模型、规范化方法和编码规则。介绍了融合事故表征和CBR的特种设备事故预测方法,其中为了更精准地检索相似案例,提出了针对不同属性类型的属性相似度计算方法、基于专家置信度的改进型AHP法、考虑时间衰减效应的案例相似度计算方法以及案例相似度阈值确定函数。通过上海某公司的汽车起重机案例验证了该方法。结果表明该方法不但能根据事故前兆信息,给出特种设备的事故原因故障树,以了解事故发展趋势,还能提供如事故特征、事故发生部位等事故表征信息的发生概率,以及应采取的预防措施。     

Maintaining Retrieval Knowledge in a Case-Based Reasoning System

The knowledge stored in a case base is central to the problem solving of a case-based reasoning (CBR) system. Therefore, case-base maintenance is a key component of maintaining a CBR system. However, other knowledge sources, such as indexing and similarity knowledge for improved case retrieval, also play an important role in CBR problem solving. For many CBR applications, the refinement of this retrieval knowledge is a necessary component of CBR maintenance. This article focuses on optimization of the parameters and feature selections/weights for the indexing and nearest-neighbor algorithms used by CBR retrieval. Optimization is applied after case-base maintenance and refines the CBR retrieval to reflect changes that have occurred to cases in the case base. The optimization process is generic and automatic, using knowledge contained in the cases. In this article we demonstrate its effectiveness on a real tablet formulation application in two maintenance scenarios. One scenario, a growing case base, is provided by two snapshots of a formulation database. A change in the company's formulation policy results in a second, more fundamental requirement for CBR maintenance. We show that after case-base maintenance, the CBR system did indeed benefit from also refining the retrieval knowledge. We believe that existing CBR shells would benefit from including an option to automatically optimize the retrieval process.     

基于样图的排样及其样图检索方法

为解决不规则图形排样问题,讨论了基于实例(样图)的推理方法在零件排样问题中的应用,给出了基于样图的排样系统结构.此方法的一个关键问题是在已知待排的零件组和板料的前提下,如何从样图库中检索出相应样图的图形匹配方法.为此提出了基于图形(组)简化骨架的模式编码的串间Findler距离的图形(组)之间相似性检索算法,并给出了算例验证.     

基于最小描述长度原则的属性图概要方法

图概要技术是管理、分析和可视化大规模图的关键技术之一。如何综合结构和属性信息进行图概要是一个挑战。大部分现有的图概要方法或者只考虑结构或属性某一方面的信息,或者要求属性的表现形式是一致的。结合信息论中最小描述长度原则,对属性图概要问题建模,将其转化为求解最小表示代价问题,以实现图压缩和图概要的双重目标。提出了一种计算节点属性相似性的方法,该属性度量方法对节点属性的限制较小,并且将节点间的相似性统一为存储代价,实现了节点结构相似和属性相似的协同考虑。提出了两种求解最小代价表示的图概要算法。在真实和合成的数据集上实验,验证了提出算法的有效性。     

融合裕度和否决权的案例相似度量方法

现有相似度量方法未考虑关键属性的否决作用与虑属性值裕度对案例推理的影响。为此,提出一种新的案例相似度量方法。定义属性值裕度和关键属性否决权,采用布尔函数、熵值理论和Composite策略等数学理论和分析工具,设计否决权和裕度属性的相似度量公式,给出先局部后全局的合并策略。实例结果表明,该方法在保证相似度量效能的前提下,能提高案例相似度量的分辨率。