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Knowledge Representation (knowledge + representation)
Selected AbstractsA reasoning method for a ship design expert systemEXPERT SYSTEMS, Issue 2 2005Sebnem Helvacioglu Abstract: The ship design process is a highly data-oriented, dynamic, iterative and multi-stage algorithm. It utilizes multiple abstraction levels and concurrent engineering techniques. Specialized techniques for knowledge acquisition, knowledge representation and reasoning must be developed to solve these problems for a ship design expert system. Consequently, very few attempts have been made to model the ship design process using an expert system approach. The current work investigates a knowledge representation,reasoning technique for such a purpose. A knowledge-based conceptual design was developed by utilizing a prototype approach and hierarchical decompositioning. An expert system program called ALDES (accommodation layout design expert system) was developed by using the CLIPS expert system shell and an object-oriented user interface. The reasoning and knowledge representation methods of ALDES are explained in the paper. An application of the method is given for the general arrangement design of a containership. [source] A connectionist inference model for pattern-directed knowledge representationEXPERT SYSTEMS, Issue 2 2000I Mitchell In this paper we propose a connectionist model for variable binding. The model is topology dependent on the graph it builds based on the predicates available. The irregular connections between perceptron-like assemblies facilitate forward and backward chaining. The model treats the symbolic data as a sequence and represents the training set as a partially connected network using basic set and graph theory to form the internal representation. Inference is achieved by opportunistic reasoning via the bidirectional connections. Consequently, such activity stabilizes to a multigraph. This multigraph is composed of isomorphic subgraphs which all represent solutions to the query made. Such a model has a number of advantages over other methods in that irrelevant connections are avoided by superimposing positionally dependent sub-structures that are identical, variable binding can be encoded and multiple solutions can be extracted simultaneously. The model also has the ability to adapt its existing architecture when presented with new clauses and therefore add new relationships/rules to the model explicitly; this is done by some partial retraining of the network due to the superimposition properties. [source] Executable declarative business rules and their use in electronic commerceINTELLIGENT SYSTEMS IN ACCOUNTING, FINANCE & MANAGEMENT, Issue 4 2001G. Antoniou Business rules are statements which are used to run the activities of an organization. In the era of electronic commerce it is important for these rules to be represented explicitly, and to be automatically applicable. In this paper we argue that methods from the field of knowledge representation can be used for this purpose. In particular, we propose the use of defeasible reasoning, a simple but efficient reasoning method based on rules and priorities. We motivate the use of defeasible reasoning, give examples, describe two case studies, and outline current and future work in our research. Copyright © 2001 John Wiley & Sons, Ltd. [source] On aggregating uncertain information by type-2 OWA operators for soft decision makingINTERNATIONAL JOURNAL OF INTELLIGENT SYSTEMS, Issue 6 2010Shang-Ming Zhou Yager's ordered weighted averaging (OWA) operator has been widely used in soft decision making to aggregate experts' individual opinions or preferences for achieving an overall decision. The traditional Yager's OWA operator focuses exclusively on the aggregation of crisp numbers. However, human experts usually tend to express their opinions or preferences in a very natural way via linguistic terms. Type-2 fuzzy sets provide an efficient way of knowledge representation for modeling linguistic terms. In order to aggregate linguistic opinions via OWA mechanism, we propose a new type of OWA operator, termed type-2 OWA operator, to aggregate the linguistic opinions or preferences in human decision making modeled by type-2 fuzzy sets. A Direct Approach to aggregating interval type-2 fuzzy sets by type-2 OWA operator is suggested in this paper. Some examples are provided to delineate the proposed technique. © 2010 Wiley Periodicals, Inc. [source] Emergence of self-learning fuzzy systems by a new virus DNA,based evolutionary algorithmINTERNATIONAL JOURNAL OF INTELLIGENT SYSTEMS, Issue 3 2003Lihong Ren In this article, we propose a new approach to the virus DNA,based evolutionary algorithm (VDNA-EA) to implement self-learning of a class of Takagi-Sugeno (T-S) fuzzy controllers. The fuzzy controllers use T-S fuzzy rules with linear consequent, the generalized input fuzzy sets, Zadeh fuzzy logic and operators, and the generalized defuzzifier. The fuzzy controllers are proved to be nonlinear proportional-integral (PI) controllers with variable gains. The fuzzy rules are discovered automatically and the design parameters in the input fuzzy sets and the linear rule consequent are optimized simultaneously by the VDNA-EA. The VDNA-EA uses the VDNA encoding method that stemmed from the structure of the VDNA to encode the design parameters of the fuzzy controllers. We use the frameshift decoding method of the VDNA to decode the DNA chromosome into the design parameters of the fuzzy controllers. In addition, the gene transfer operation and bacterial mutation operation inspired by a microbial evolution phenomenon are introduced into the VDNA-EA. Moreover, frameshift mutation operations based on the DNA genetic operations are used in the VDNA-EA to add and delete adaptively fuzzy rules. Our encoding method can significantly shorten the code length of the DNA chromosomes and improve the encoding efficiency. The length of the chromosome is variable and it is easy to insert and delete parts of the chromosome. It is suitable for complex knowledge representation and is easy for the genetic operations at gene level to be introduced into the VDNA-EA. We show how to implement the new method to self-learn a T-S fuzzy controller in the control of a nonlinear system. The fuzzy controller can be constructed automatically by the VDNA-EA. Computer simulation results indicate that the new method is effective and the designed fuzzy controller is satisfactory. © 2003 Wiley Periodicals, Inc. [source] Concepts and semantic relations in information scienceJOURNAL OF THE AMERICAN SOCIETY FOR INFORMATION SCIENCE AND TECHNOLOGY, Issue 10 2010Wolfgang G. Stock Concept-based information retrieval and knowledge representation are in need of a theory of concepts and semantic relations. Guidelines for the construction and maintenance of knowledge organization systems (KOS) (such as ANSI/NISO Z39.19-2005 in the U.S.A. or DIN 2331:1980 in Germany) do not consider results of concept theory and theory of relations to the full extent. They are not able to unify the currently different worlds of traditional controlled vocabularies, of the social web (tagging and folksonomies) and of the semantic web (ontologies). Concept definitions as well as semantic relations are based on epistemological theories (empiricism, rationalism, hermeneutics, pragmatism, and critical theory). A concept is determined via its intension and extension as well as by definition. We will meet the problem of vagueness by introducing prototypes. Some important definitions are concept explanations (after Aristotle) and the definition of family resemblances (in the sense of Wittgenstein). We will model concepts as frames (according to Barsalou). The most important paradigmatic relation in KOS is hierarchy, which must be arranged into different classes: Hyponymy consists of taxonomy and simple hyponymy, meronymy consists of many different part-whole-relations. For practical application purposes, the transitivity of the given relation is very important. Unspecific associative relations are of little help to our focused applications and should be replaced by generalizable and domain-specific relations. We will discuss the reflexivity, symmetry, and transitivity of paradigmatic relations as well as the appearance of specific semantic relations in the different kinds of KOS (folksonomies, nomenclatures, classification systems, thesauri, and ontologies). Finally, we will pick out KOS as a central theme of the Semantic Web. [source] Ethical decision-making for knowledge representation and organization systems for global useJOURNAL OF THE AMERICAN SOCIETY FOR INFORMATION SCIENCE AND TECHNOLOGY, Issue 9 2005Clare Beghtol In this article, ethical decision-making methods for creating, revising, and maintaining knowledge representation and organization systems are described, particularly in relation to the global use of these systems. The analysis uses a three-level model and the literature on ethically based decision-making in the social and technical sciences. In addition, methods for making these kinds of decisions in an ethical manner are presented. This multidisciplinary approach is generalizable to other information areas and is useful for encouraging the development of ethics policies for knowledge representation and organization systems and for other kinds of systems or institutions. [source] Schema Theory and Knowledge-Based Processes in Second Language Reading Comprehension: A Need for Alternative PerspectivesLANGUAGE LEARNING, Issue 2007Hossein Nassaji How is knowledge represented and organized in the mind? What role does it play in discourse comprehension and interpretation? What are the exact mechanisms whereby knowledge-based processes are utilised in comprehension? These are questions that have puzzled psycholinguists and cognitive psychologists for years. Despite major developments in the field of second language (L2) reading over the last two decades, many attempts at explaining the role of knowledge in L2 comprehension have been made almost exclusively in the context of schema theory, a perspective that provides an expectation-driven conception of the role of knowledge and considers that preexisting knowledge provides the main guiding context through which information is processed and interpreted. In this article, I first review and critically analyze the major assumptions underlying schema theory and the processes that it postulates underlie knowledge representation and comprehension. Then I consider an alternative perspective, a construction-integration model of discourse comprehension, and discuss how this perspective, when applied to L2 reading comprehension, offers a fundamentally different and more detailed account of the role of knowledge and knowledge-based processes that L2 researchers had previously tried to explain within schema-theoretic principles. [source] What are the learning affordances of 3-D virtual environments?BRITISH JOURNAL OF EDUCATIONAL TECHNOLOGY, Issue 1 2010Barney Dalgarno This article explores the potential learning benefits of three-dimensional (3-D) virtual learning environments (VLEs). Drawing on published research spanning two decades, it identifies a set of unique characteristics of 3-D VLEs, which includes aspects of their representational fidelity and aspects of the learner,computer interactivity they facilitate. A review of applications of 3-D VLEs is presented, leading to the identification of a series of learning affordances of such environments. These affordances include the facilitation of tasks that lead to enhanced spatial knowledge representation, greater opportunities for experiential learning, increased motivation/engagement, improved contextualisation of learning and richer/more effective collaborative learning as compared to tasks made possible by 2-D alternatives. The authors contend that the continued development of and investment in 3-D games, simulations and virtual worlds for educational purposes should be considered contingent on further investigation into the precise relationships between the unique characteristics of 3-D VLEs and their potential learning benefits. To this end, they conclude by proposing an agenda or ,roadmap' for future research that encompasses empirical studies aimed at exploring these relationships, as well as those aimed at deriving principles and guidelines to inform the design, development and use of 3-D virtual environments for learning. [source] Transfer of Mathematical Knowledge: The Portability of Generic InstantiationsCHILD DEVELOPMENT PERSPECTIVES, Issue 3 2009Jennifer A. Kaminski Abstract, Mathematical concepts are often difficult to acquire. This difficulty is evidenced by failure of knowledge to transfer to novel analogous situations. One approach to this challenge is to present the learner with a concrete instantiation of the to-be-learned concept. Concrete instantiations communicate more information than their abstract, generic counterparts and, in doing so, they may facilitate initial learning. However, this article argues that extraneous information in concrete instantiations may distract the learner from the relevant mathematical structure and, as a result, hinder transfer. At the same time, generic instantiations, such as traditional mathematical notation, can be learned by both children and adults and can, in turn, allow for transfer, suggesting that generic instantiations result in a portable knowledge representation. [source] Implications of Evidence-Centered Design for Educational TestingEDUCATIONAL MEASUREMENT: ISSUES AND PRACTICE, Issue 4 2006Robert J. Mislevy Evidence-centered assessment design (ECD) provides language, concepts, and knowledge representations for designing and delivering educational assessments, all organized around the evidentiary argument an assessment is meant to embody. This article describes ECD in terms of layers for analyzing domains, laying out arguments, creating schemas for operational elements such as tasks and measurement models, implementing the assessment, and carrying out the operational processes. We argue that this framework helps designers take advantage of developments from measurement, technology, cognitive psychology, and learning in the domains. Examples of ECD tools and applications are drawn from the Principled Assessment Design for Inquiry (PADI) project. Attention is given to implications for large-scale tests such as state accountability measures, with a special eye for computer-based simulation tasks. [source] Sharing in teams of heterogeneous, collaborative learning agentsINTERNATIONAL JOURNAL OF INTELLIGENT SYSTEMS, Issue 2 2009Christopher M. Gifford This paper is focused on the effects of sharing knowledge and collaboration of multiple heterogeneous, intelligent agents (hardware or software) which work together to learn a task. As each agent employs a different machine learning technique, the system consists of multiple knowledge sources and their respective heterogeneous knowledge representations. Collaboration between agents involves sharing knowledge to both speed up team learning, as well as refine the team's overall performance and group behavior. Experiments have been performed that vary the team composition in terms of machine learning algorithms, learning strategies employed by the agents, and sharing frequency for a predator-prey cooperative pursuit task. For lifelong learning, heterogeneous learning teams were more successful than homogeneous learning counterparts. Interestingly, sharing increased the learning rate, but sharing with higher frequency showed diminishing results. Lastly, knowledge conflicts are reduced over time the more sharing takes place. These results support further investigation of the merits of heterogeneous learning. © 2008 Wiley Periodicals, Inc. [source] Student perceptions about the characteristics of an effective discussion during the reporting phase in problem-based learningMEDICAL EDUCATION, Issue 9 2006Astrid J S F Visschers-Pleijers Objective, To explore student perceptions of factors contributing to the effectiveness of discussions in the reporting phase of the problem-based learning (PBL) process, where students report and synthesise the results of self-study. Methods, Forty-eight Year 1 and 2 medical students participated in 6 focus group interviews about the characteristics of effective group discussions and possible improvements. The data were analysed qualitatively in several stages. Results, The analysis yielded 4 main characteristics of effective discussions: asking for, giving and receiving explanations; integrating and applying knowledge; discussing differences with regard to learning content, and guiding and monitoring the content and the group process of the discussion. Integrating and applying knowledge included structuring, relating and summarising information and providing examples from practice. Discussing different opinions included discussing a variety of literature resources and disagreements. The main learning effects mentioned by the students were retention, understanding, integration and application of knowledge. Conclusions, Students have clear ideas about what promotes effective discussions during the reporting phase. Their PBL experience has provided them with some insights that are in line with theory and research on collaborative learning. Future research should examine differences between student and tutor perceptions of the quality of discussions. Introductions to PBL for students and tutors should include training in asking open but focused questions, supporting explanations with arguments and dealing with conflicts about learning content. Tutors should be trained in giving effective and personal feedback. Collaborative creation of external knowledge representations (i.e. concept maps) should be advocated, as should variety of literature resources. [source] | |||||||||||||