• 제목/요약/키워드: Fuzzy Set-Fuzzy Systems

검색결과 665건 처리시간 0.031초

Wavelet Analysis to Real-Time Fabric Defects Detection in Weaving processes

  • Kim, Sung-Shin;Bae, Hyeon;Jung, Jae-Ryong;Vachtsevanos, George J.
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • 제2권1호
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    • pp.89-93
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    • 2002
  • This paper introduces a vision-based on-line fabric inspection methodology of woven textile fabrics. Current procedure for determination of fabric defects in the textile industry is performed by human in the off-line stage. The advantage of the on-line inspection system is not only defect detection and identification, but also 벼ality improvement by a feedback control loop to adjust set-points. The proposed inspection system consists of hardware and software components. The hardware components consist of CCD array cameras, a frame grabber and appropriate illumination. The software routines capitalize upon vertical and horizontal scanning algorithms characteristic of a particular deflect. The signal to noise ratio (SNR) calculation based on the results of the wavelet transform is performed to measure any deflects. The defect declaration is carried out employing SNR and scanning methods. Test results from different types of defect and different style of fabric demonstrate the effectiveness of the proposed inspection system.

A Study on Improving the Effectiveness of Information Retrieval Through P-norm, RF, LCAF

  • Kim, Young-cheon;Lee, Sung-joo
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • 제2권1호
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    • pp.9-14
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    • 2002
  • Boolean retrieval is simple and elegant. However, since there is no provision for term weighting, no ranking of the answer set is generated. As a result, the size of the output might be too large or too small. Relevance feedback is the most popular query reformulation strategy. in a relevance feedback cycle, the user is presented with a list of the retrieved documents and, after examining them, marks those which are relevant. In practice, only the top 10(or 20) ranked documents need to be examined. The main idea consists of selecting important terms, or expressions, attached to the documents that have been identified as relevant by the user, and of enhancing the importance of these terms in a new query formulation. The expected effect is that the new query will be moved towards the relevant documents and away from the non-relevant ones. Local analysis techniques are interesting because they take advantage of the local context provided with the query. In this regard, they seem more appropriate than global analysis techniques. In a local strategy, the documents retrieved for a given query q are examined at query time to determine terms for query expansion. This is similar to a relevance feedback cycle but might be done without assistance from the user.

A Multiagent System for Workflow-Based Bioinformatics Tool Integration

  • Sohn, Bong-Ki;Lee, Keon-Myung;Kim, Hak-Joon
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • 제3권2호
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    • pp.133-137
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    • 2003
  • Various bioinformatics tools for biological data processing have been developed and most of them are available in public. Most bioinformatics works are carried out by a composite application of those tools. Several integration approaches have been proposed for easy use of the tools. This paper proposes a new multi agent system to integrate bioinformatics tools in the perspective of workflow since the composite applications of tools can be regarded as workflows. For the easy integration, the proposed system employs wrapper agents for existing tools, uses XML-based messages in the inter-agent communication, and agents are supposed to extract necessary information from the received messages. This allows new tools to be easily added on the integration framework. The proposed method allows various control structures in workflow definition and provides the progress monitoring capability of the on-going workflows. In particular, agents in this system have the rule-based architecture which allows the defined rule set to be a special role agent. This feature provides fast and flexible agent development to aid in managing the complexity of bioinformatics application. This system has been partially implemented and has been proven to be a viable implementation for workflow-based bioinformatics tool integration.

Rank-based Control of Mutation Probability for Genetic Algorithms

  • Jung, Sung-Hoon
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • 제10권2호
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    • pp.146-151
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    • 2010
  • This paper proposes a rank-based control method of mutation probability for improving the performances of genetic algorithms (GAs). In order to improve the performances of GAs, GAs should not fall into premature convergence phenomena and should also be able to easily get out of the phenomena when GAs fall into the phenomena without destroying good individuals. For this, it is important to keep diversity of individuals and to keep good individuals. If a method for keeping diversity, however, is not elaborately devised, then good individuals are also destroyed. We should devise a method that keeps diversity of individuals and also keeps good individuals at the same time. To achieve these two objectives, we introduce a rank-based control method of mutation probability in this paper. We set high mutation probabilities to lowly ranked individuals not to fall into premature convergence phenomena by keeping diversity and low mutation probabilities to highly ranked individuals not to destroy good individuals. We experimented our method with typical four function optimization problems in order to measure the performances of our method. It was found from extensive experiments that the proposed rank-based control method could accelerate the GAs considerably.

Semi-Supervised Recursive Learning of Discriminative Mixture Models for Time-Series Classification

  • Kim, Minyoung
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • 제13권3호
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    • pp.186-199
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    • 2013
  • We pose pattern classification as a density estimation problem where we consider mixtures of generative models under partially labeled data setups. Unlike traditional approaches that estimate density everywhere in data space, we focus on the density along the decision boundary that can yield more discriminative models with superior classification performance. We extend our earlier work on the recursive estimation method for discriminative mixture models to semi-supervised learning setups where some of the data points lack class labels. Our model exploits the mixture structure in the functional gradient framework: it searches for the base mixture component model in a greedy fashion, maximizing the conditional class likelihoods for the labeled data and at the same time minimizing the uncertainty of class label prediction for unlabeled data points. The objective can be effectively imposed as individual mixture component learning on weighted data, hence our mixture learning typically becomes highly efficient for popular base generative models like Gaussians or hidden Markov models. Moreover, apart from the expectation-maximization algorithm, the proposed recursive estimation has several advantages including the lack of need for a pre-determined mixture order and robustness to the choice of initial parameters. We demonstrate the benefits of the proposed approach on a comprehensive set of evaluations consisting of diverse time-series classification problems in semi-supervised scenarios.

A Framework for Universal Cross Layer Networks

  • Khalid, Murad;Sankar, Ravi;Joo, Young-Hoon;Ra, In-Ho
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • 제8권4호
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    • pp.239-247
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    • 2008
  • In a resource-limited wireless communication environment, various approaches to meet the ever growing application requirements in an efficient and transparent manner, are being researched and developed. Amongst many approaches, cross layer technique is by far one of the significant contributions that has undoubtedly revolutionized the way conventional layered architecture is perceived. In this paper, we propose a Universal Cross Layer Framework based on vertical layer architecture. The primary contribution of this paper is the functional architecture of the vertical layer which is primarily responsible for cross layer interaction management and optimization. The second contribution is the use of optimization cycle that comprises awareness parameters collection, mapping, classification and the analysis phases. The third contribution of the paper is the decomposition of the parameters into local and global network perspective for opportunistic optimization. Finally, we have shown through simulations how parameters' variations can represent local and global views of the network and how we can set local and global thresholds to perform opportunistic optimization.

퍼지추론 기반 대표 키워드 추출방법의 성능 평가 (Performance Evaluation of the Extractiojn Method of Representative Keywords by Fuzzy Inference)

  • 노순억;김병만;오상엽;이현아
    • 한국산업정보학회논문지
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    • 제10권1호
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    • pp.28-37
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    • 2005
  • 본 논문은 퍼지 추론을 이용하여 소수문서로부터 대표 용어들을 추출하고 가중치를 부여하는 기존 방법의 유용성을 평가하고자 GIS (Generalized Instance Set) 알고리즘에 이를 적용시켜 그 성능을 평가하여 보았다. GIS 는 학습 문서 집합에 대한 일반화 (generalization) 과정을 통해 문서 그룹들을 형성하고 이 그룹의 대표 문서 (generalized instance)를 생성한 후 k- 알고리즘을 적용하는 방법이다. 본 논문에서는 바로 이 일반화 과정의 한 방법으로 퍼지 추론을 이용한 방법을 사용하였다. 상대적 성능 평가를 위하여 이 일반화(generalization) 과정에 Rocchio와 Widrow-Hoff 방법도 적용시켜 문서 분류 성능을 비교하였다. 실험 결과, 긍정적 문서만을 고려할 경우는 좋은 성능을 보이지만 부정적 문서를 같이 고려할 경우는 성능이 상대적으로 좋지 않음을 확인 할 수 있었다.

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지식기반시스템에서 불확실성처리방법의 비교연구 (A Comparative Study of Uncertainty Handling Methods in Knowledge-Based System)

  • 송수섭
    • 한국국방경영분석학회지
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    • 제23권2호
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    • pp.45-71
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    • 1997
  • There has been considerable research recently on uncertainty handling in the fields of artificial intelligence and knowledge-based system. Various numerical and non-numerical methods have been proposed for representing and propagating uncertainty in knowledge-based system. The Bayesian method, the Dempster-Shafer's Evidence Theory, the Certainty Factor model and the Fuzzy Set Theory are most frequently appeared in the knowledge-based system. Each of these four methods views uncertainty from a different perspective and propagates it differently. There is no single method which can handle uncertainty properly in all kinds of knowledge-based systems' domain. Therefore a knowledge-based system will work more effectively when the uncertainty handling method in the system fits to the system's environment. This paper proposed a framework for selecting proper uncertainty handling methods in knowledge-based system with respect to characteristics of problem domain and cognitive styles of experts. A schema with strategic/operational and unstructured/structured classification is employed to differenciate domain. And a schema with systematic/intuitive and preceptive/receptive classification is employed to differenciate experts' cognitive style. The characteristics of uncertainty handling methods are compared with characteristics of problem domains and cognitive styles respectively. Then a proper uncertainty handling method is proposed for each category.

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Data Mining-Aided Automatic Landslide Detection Using Airborne Laser Scanning Data in Densely Forested Tropical Areas

  • Mezaal, Mustafa Ridha;Pradhan, Biswajeet
    • 대한원격탐사학회지
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    • 제34권1호
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    • pp.45-74
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    • 2018
  • Landslide is a natural hazard that threats lives and properties in many areas around the world. Landslides are difficult to recognize, particularly in rainforest regions. Thus, an accurate, detailed, and updated inventory map is required for landslide susceptibility, hazard, and risk analyses. The inconsistency in the results obtained using different features selection techniques in the literature has highlighted the importance of evaluating these techniques. Thus, in this study, six techniques of features selection were evaluated. Very-high-resolution LiDAR point clouds and orthophotos were acquired simultaneously in a rainforest area of Cameron Highlands, Malaysia by airborne laser scanning (LiDAR). A fuzzy-based segmentation parameter (FbSP optimizer) was used to optimize the segmentation parameters. Training samples were evaluated using a stratified random sampling method and set to 70% training samples. Two machine-learning algorithms, namely, Support Vector Machine (SVM) and Random Forest (RF), were used to evaluate the performance of each features selection algorithm. The overall accuracies of the SVM and RF models revealed that three of the six algorithms exhibited higher ranks in landslide detection. Results indicated that the classification accuracies of the RF classifier were higher than the SVM classifier using either all features or only the optimal features. The proposed techniques performed well in detecting the landslides in a rainforest area of Malaysia, and these techniques can be easily extended to similar regions.

시소러스의 연관성 정보를 이용한 문서의 순위 결정 방법 (Document ranking methods using term dependencies from a thesaurus)

  • 이준호
    • 정보관리학회지
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    • 제10권2호
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    • pp.3-22
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    • 1993
  • 최근 시소러스를 기반으로 하는 불리안 검색 시스템에서 문서의 순위 결정에 사용 될 수 있는 Relevance, R-distance, K-distance와 같은 방법들이 개발되었다. 이러한 방법들은 색인어들 사이의 연관성 정보를 이용하여 문서들의 순위를 결정함으로써 많은 경우에 높은 검색 효율을 제공할 지라도, 불리안 연산자 AND, OR, NOT에 대한 연산 방법이 문제점으로 지적되어왔다. 본 논문에서는 개선된 퍼지 집합 모델과 확장된 불리안 모델을 시소러스가 제공하는 색인어들 사이의 연관성 정보를 효율적으로 이용할 수 있도록 확장함으로써, 기존 방법들의 문제점을 극복하는 새로운 순위 결정 방법 KB-FSM과 KB-EBM을 제안한다. 또한 KB-FSM과 KB-EBM이 Relevance, R-distance, K-distance보다 문서들의 순위를 보다 정확하게 결정함을 성능 비교를 통하여 입증한다.

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