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1.
基于知识的问题求解需要一个丰富而相对完备的信念系统,尤其是当任务具有领域非限定特征时。经典知识工程关于知识获取、表示与使用的方法只能适应领域受限问题,因为它不是从概念发展的角度来建构概念系统的,面临着Framework Problem。针对认知心理学对概念系统发展与表征问题研究有一定的认知深度同时又缺乏系统构造与实现机制研究的情况,提出了一种基于框架表征的概念系统表征与发展方法,详细研究了概念在内的隐水平I、外显水平E1、外显水平E2和外显水平E3上的表征和发展过程。这一研究对于提高基于知识的系统推理能力和问题求解能力具有显著意义。 相似文献
2.
In order to better study team behavior and performance, much attention has focused on obtaining team members' mental models for the purposes of analysis and prediction. This paper describes a knowledge capture approach and a supporting graphical tool that together allow for direct acquisition of team mental models in the form of conceptual graphs. We performed acquisition experiments on over one hundred teams where team members used the tool to specify their team process. In addition to acquiring team members' models, non-team observers created “expert” models of the team process for comparison. We obtained good results on accepted measures of recall and precision compared to the “expert” models. 相似文献
3.
Automated knowledge acquisition for design and manufacturing: The case of micromachined atomizer 总被引:2,自引:0,他引:2
In order to remain competitive in the global market, original equipment manufacturers (OEMs) are developing a process-based, knowledge-driven product development environment with emphasis on the acquisition, storing, and utilization of manufacturing knowledge. This is usually achieved by using the symbolic artificial intelligence (AI) approach. Specifically, knowledge-based expert systems are developed to capture human expertise, mostly in terms of IF–THEN production rules. It has been recognized that the development of symbolic knowledge-based expert systems suffers from the so-called knowledge acquisition bottleneck. Knowledge acquisition is the process of collecting domain knowledge and transforming the knowledge into a computerized representation. It is a challenging and time-consuming process due to the difficulties involved in eliciting knowledge from human experts. This paper presents an automated approach for knowledge acquisition by integrating neural networks learning ability and fuzzy logics structured knowledge representation. Using this approach, knowledge is automatically acquired from data and represented using humanly intelligible fuzzy rules. The approach is applied to a case study of the design and manufacturing of micromachined atomizers for gas turbine engine. The influence of geometric features on the performance of the atomizers is investigated. The results are then compared with those obtained using traditional regression analysis approach (abstract mathematical models). It was found that the automated approach provides an efficient means for knowledge acquisition. Since the fuzzy rules extracted are easy to understand, they can be used to allow more clear specification of manufacturing processes and to shorten learning curves for novice manufacturing engineers. 相似文献
4.
At present, the Entity-Relationship (ER) model is the most important paradigm for conceptual database design. Since the model was introduced in the mid-seventies, a large body of literature has been published on transforming conceptual ER schemas or diagrams into logical data models. The purpose of this paper is to survey this literature. A first focus is on transformation approaches from the ER model to traditional data models, i.e. to the relational, the network, or the hierarchical model; this is then complemented by a discussion of more recent transformations to object-oriented models. A second focus is on considering the process of reverse engineering, i.e. transformations from a logical model back into the ER model; finally, an overview of direct transformations between various logical data models is presented. 相似文献
5.
Constraints provide a flexible and uniform way to represent diverse data capturing spatio-temporal behavior, complex modeling requirements, partial and incomplete information etc, and have been used in a wide variety of application domains. Constraint databases have recently emerged to deeply integrate data captured by constraints in databases. This paper reports on the development of the first constraint object-oriented database system, CCUBE, and describes its specification, design and implementation. The CCUBE system is designed to be used for the implementation and optimization of high-level constraint object-oriented query languages as well as for directly building software systems requiring extensible use of constraint database features. The CCUBE data manipulation language, Constraint Comprehension Calculus, is an integration of a constraint calculus for extensible constraint domains within monoid comprehensions, which serve as an optimization-level language for object-oriented queries. The data model for the constraint calculus is based on constraint spatio-temporal (CST) objects that may hold spatial, temporal or constraint data, conceptually represented by constraints. New CST objects are constructed, manipulated and queried by means of the constraint calculus. The model for the monoid comprehensions, in turn, is based on the notion of monoids, which is a generalization of collection and aggregation types. The focal point of our work is achieving the right balance between the expressiveness, complexity and representation usefulness, without which the practical use of the system would not be possible. To that end, CCUBE constraint calculus guarantees polynomial time data complexity, and, furthermore, is tightly integrated with the monoid comprehensions to allow deeply interleaved global optimization. 相似文献
6.
7.
Emmanuel Brousseau Stefan Dimov Rossitza Setchi 《Journal of Intelligent Manufacturing》2008,19(1):21-32
Automatic Feature Recognition (AFR) techniques are an important tool for achieving a true integration of design and manufacturing
stages during the product development. In particular, AFR systems offer capabilities for recognising high-level geometrical
entities, features, in Computer-Aided Design (CAD) models. However, the recognition performances of most of the existing AFR
systems are limited to the requirements of specific applications. This paper presents automatic knowledge acquisition techniques
to support the development of AFR systems that could be deployed in different application domains. In particular, a method
to generate automatically feature recognition rules is proposed. These rules are formed by applying an inductive learning
algorithm on training data consisting of feature examples. In addition, a technique for defining automatically feature hints
from such rule sets is described. The knowledge acquisition techniques presented in this study are implemented within a prototype
feature recognition system and its capabilities are verified on two benchmarking parts. 相似文献
8.
林琪 《计算机工程与科学》1997,19(1):68-72
约束逻辑程序设计(CLP)方法是提高PROLOG语言效率的一种崭新方法,本文针对SC┐PROLOG解释系统的实现介绍其相应设计思想,从域变量含义入手,提出了域及约束的存储方法以及约束机制的实现算法,是对逻辑设计方法研究的一点体会 相似文献
9.
Knowledge, as the most important resource for the knowledge economy in the 21st century, is fundamental to enterprise competitive strength. Therefore, how to effectively integrate internal and external knowledge and provide correct knowledge to the right users in a timely fashion have become key success factors in business operation. 相似文献
10.
Logic programming requires that the programmer convert a problem into a set of constraints based on predicates. Choosing the predicates and introducing appropriate constraints can be intricate and error prone. If the problem domain is structured enough, we can let the programmer express the problem in terms of more abstract, higher‐level constraints. A compiler can then convert the higher‐level program into a logic‐programming formalism. The compiler writer can experiment with alternative low‐level representations of the higher‐level constraints in order to achieve a high‐quality translation. The programmer can then take advantage of both a reduction in complexity and an improvement in runtime speed for all problems within the domain. We apply this analysis to the domain of tabular constraint‐satisfaction problems. Examples of such problems include logic puzzles solvable on a hatch grid and combinatorial problems such as graph coloring and independent sets. The proper abstractions for these problems are rows, columns, entries, and their interactions. We present a higher‐level language, Constraint Lingo, dedicated to problems in this domain. We also describe how we translate programs from Constraint Lingo into lower‐level logic formalisms such as the logic of propositional schemata. These translations require that we choose among competing lower‐level representations in order to produce efficient results. The overall effectiveness of our approach depends on the appropriateness of Constraint Lingo, our ability to translate Constraint Lingo programs into high‐quality representations in logic formalisms, and the efficiency with which logic engines can compute answer sets. We comment on our computational experience with these tools in solving both graph problems and logic puzzles. Copyright © 2004 John Wiley & Sons, Ltd. 相似文献
11.
This paper presents an automated knowledge acquisition architecture for the truck docking problem. The architecture consists of a neural network block, a fuzzy rule generation block and a genetic optimisation block. The neural network block is used to quickly and adaptively learn from trials the driving knowledge. The fuzzy rule generation block then extracts the driving knowledge to form a knowledge rule base. The driving knowledge rule base is further optimised in the genetic optimisation block using a genetic algorithm. Computer simulations are presented to show the effectiveness of the architecture. 相似文献
12.
并发约束程序设计语言COPS及其执行模型 总被引:1,自引:0,他引:1
约束程序设计尤其是约束逻辑程序设计与并发约束程序设计在AI程序设计领域占据着越来越重要的位置。传统逻辑程序设计的基“计算即为定理证明”的计算风格虽获得了简洁优美的操作语义特性,但也付出了执行效率低的代价,当应用系统规模增大时,其性能严重下降以致崩溃。针对传统逻辑程序设计的这种可伸缩性问题,设计了一个基于并发约束程序设计概念的说明性语言COPS,旨在从语言设计与执行模型两方面降低说明性程序的不确定性,提高搜索与运行效率。在语言设计方面,通过引入确定性语言成分,避免不确定计算用于确定性目标所浪费的系统开销;在执行模型方面,在目标的并发穿叉执行与数据驱动的并发同步机制的基础上,实现“优先执行确定目标”策略与“最少假定”策略,作为约束传播的延伸,最大幅度地剪枝搜索空间,降低搜索复杂性。COPS提供的知识表示、推理与并发机制使其成为构造agent程序的理想语言。论文给出COPS语言的语法规范与执行模型的操作语义描述。 相似文献
13.
约束推理是人工智能中主要组成部分之一,可以解决实际优化调度和规划过程中的约束求解问题。这里在解释了约束逻辑程序设计的原理和过程基础上,打破封闭式约束逻辑程序设计系统,从软件工程上采用统一建模语言,提出一种新的开放的可扩展型约束逻辑程序设计结构系统。为实现可扩展的约束推理搜索系统,引进UML建模语言中用例图、类图和协作图。在建模基础上详细说明了可扩展约束逻辑程序设计中数学模型,搜索引擎和搜索驱动三者间的关系以及它们内部的工作内容。最后在描述系统结构后,提出了可扩展的内容。根据扩展因素,外界为满足更多的需要可扩展本系统的约束过滤器。 相似文献
14.
Linear constraint databases (LCDBs) extend relational databases to include linear arithmetic constraints in both relations and queries. A LCDB can also be viewed as a powerful extension of linear programming (LP) where the system of constraints is generalized to a database containing constraints and the objective function is generalized to a relational query containing constraints. Our major concern is query optimization in LCDBs. Traditional database approaches are not adequate for combination with LP technology. Instead, we propose a new query optimization approach, based on statistical estimations and iterated trials of potentially better evaluation plans. The resulting algorithms are not only effective on LCDBs, but also applicable to existing query languages. A number of specific constraint algebra algorithms are also developed: select-project-join for two relations, constraint sort-join and constraint multi-join. 相似文献
15.
Journal of Computer Science and Technology - We extend the constraint data model to allow complex objects and study the expressive power of various query languages over this sort of constraint... 相似文献
16.
A federated database is comprised of multiple interconnected database systems that primarily operate independently but cooperate to a certain extent. Global integrity constraints can be very useful in federated databases, but the lack of global queries, global transaction mechanisms, and global concurrency control renders traditional constraint management techniques inapplicable. This paper presents a threefold contribution to integrity constraint checking in federated databases: (1) The problem of constraint checking in a federated database environment is clearly formulated. (2) A family of protocols for constraint checking is presented. (3) The differences across protocols in the family are analyzed with respect to system requirements, properties guaranteed by the protocols, and processing and communication costs. Thus, our work yields a suite of options from which a protocol can be chosen to suit the system capabilities and integrity requirements of a particular federated database environment. 相似文献
17.
William Faulkner's non-chronological story tellingstyle has long been a challenge to critics and apuzzle to beginning literature students. ``A Rose forEmily,' one of Faulkner's most frequently anthologizedstories, exemplifies the complexity of Faulkner'streatment of time. In this paper, we apply aconstraint-based problem solving method to an analysisof the chronology of ``A Rose for Emily.' Constraintlogic programming is a declarative programminglanguage paradigm that solves problems by enforcingconstraints among variables. CLP's ability to sortnumeric variables that do not yet have definite valuesmakes it possible to sort the events of ``A Rose forEmily' with only fragmented and relative timeinformation. In attempting to sort the events of thestory, we find an inconsistency in the temporalreferences scattered throughout the narrative. Afterremoving this inconsistency, we are able to compareour chronology with earlier ones and discuss thethematic relevance of Faulkner's nonlinear plots. 相似文献
18.
To understand useful strategies for guiding the design process, we analyze the relationship between the use of prototypes and design knowledge acquisition. Prototyping in five design projects at a science museum is analyzed and compared. We also extract situations in which design knowledge is acquired from prototyping. 相似文献
19.
M.A. Cárdenas Viedma R. Marín Morales 《Annals of Mathematics and Artificial Intelligence》2002,36(4):357-380
In this paper we establish the relationship between the syntax and semantics of a fuzzy temporal constraint logic (FTCL) proposed by Cárdenas et al. FTCL enables us to express interrelated events by means of fuzzy temporal constraints. Moreover, it provides a resolution principle for performing inferences which take these constraints into account. FTCL is compatible with the theoretical temporal reasoning model proposed by Marín et al. – the Fuzzy Temporal Constraint Networks (FTCN). The main contributions of this paper are, on the one hand, the proofs of the FTCL-deduction and the FTCL-refutation theorems, and, on the other, the proof of the soundness of the refutation by resolution in this formal system, together with an exhaustive study of its completeness. 相似文献
20.
The NOVI Information Model (IM) and the corresponding data models are the glue between the software components in the NOVI Service Layer. The IM enables the communication among the various components of the NOVI Architecture and supports the various functionalities it offers. The NOVI IM consists of three main ontologies: resource, monitoring and policy ontology that have evolved over time to accommodate the emerging requirements of the NOVI architecture. This article presents the NOVI IM and its ontologies, together with an overview of how the NOVI software prototypes have benefited from using the IM. 相似文献