• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2001년도 ICCAS
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• pp.165.1-165
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• 2001

The evolution strategy is a good evolutionary algorithm to find the global optimum of a real-valued function. Since many engineering problems can be formulated as real valued function optimization, the evolution strategy is frequently employed in engineering fields. However, in many engineering optimization problems, an optimization parameter is often restricted in the bounded region between two specified values, the minimum and the maximum limit, respectively. Since an offspring individual is generated randomly around a parent individual during mutation process of the evolution strategy, an individual outside the search region can be generated even if the parent is inside the search region. This paper proposes two new boundary-handling techniques for evolution strategies. One is the ...

• 한국도서관정보학회지
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• 제31권4호
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• pp.191-212
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• 2000

본 연구에서는 데이터마이닝 기법을 이용한 검색엔진인, Northernlight와 Google과 일반메타탐색엔진인 Metacrawler를 정도률, 제현률을 기준으로 검색효율성을 측정하였다. 분석결과 데이터마이닝 기법을 이용한 검색엔진이 일반검색엔진에 비해 검색효율성이 높은 것으로 나타났다. 따라서, 데이터마이닝 기법을 이용한 검색엔진이 앞으로 검색효율성을 높이는데 기여를 할 수 있을 것으로 기대된다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1997년도 하계학술대회 논문집 D
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• pp.1088-1090
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• 1997

This paper presents an effective methodology of optimal environmental and economic operation using evolution strategy. In power systems, evolution strategy, based on natural selection and genetics, can analyze non-linear and discontinuous functions in global search techniques. The formulation using this search techniques is multi-objective function, which consists of fuel cost and environmental effects concerning the pollution of the Earth's atmosphere caused by the emission of $SO_2$ and $NO_x$ from thermal generator plants. The proposed algorithms are applied on system with 6 generator.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2000년도 하계종합학술대회 논문집(4)
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• pp.143-146
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• 2000

Motion Estimation/compensation(ME/MC) is one of the efficient interframe ceding techniques for its ability to reduce the high redundancy between successive frames of an image sequence. Calculating the blocking matching takes most of the encoding time. In this paper a new fast block matching algorithm(BMA) is developed for motion estimation and for reduction of the computation time to search motion vectors. The feature of the new algorithm comes from the center-biased checking concept and the trend of pixel movements. At first, Motion Vector(MV) is searched in ${\pm}$1 of search area and then the motion estimation is exploited in the rest block. The ASP and MSE of the proposed search algorithm show good performance.

• 한국정밀공학회지
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• 제16권1호통권94호
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• pp.116-124
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• 1999

In most conventional design optimization of dynamic system, design sensitivities are utilized. However, design sensitivities based optimization method has numbers of drawback. First, computing design sensitivities for dynamic system is mathematically difficult, and almost impossible for many complex problems as well. Second, local optimum is obtained. On the other hand, Genetic Algorithm is the search technique based on the performance of system, not on the design sensitivities. It is the search algorithm based on the mechanics of natural selection and natural genetics. GA search, differing from conventional search techniques, starts with an initial set of random solutions called a population. Each individual in the population is called a chromosome, representing a solution to the problem at hand. The chromosomes evolve through successive iterations, called generations. As the generation is repeated, the fitness values of chromosomes were maximized, and design parameters converge to the optimal. In this study, Genetic Algorithm is applied to the actual dynamic optimization problems, to determine the optimal design parameters of the dynamic system.

• 한국지능시스템학회:학술대회논문집
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• 한국퍼지및지능시스템학회 1996년도 추계학술대회 학술발표 논문집
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• pp.290-293
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• 1996

This paper proposes a scheme of initial cluster center selection in FCM algorithm using the genetic algorithms. The FCM algorithm often fails in the search for global optimum because it is local search techniques that search for the optimum by using hill-climbing procedures. To solve this problem, we search for a hypersphere encircling each clusters whose parameters are estimated by the genetic algorithms. Then instead of a randomized initialization for fuzzy partition matrix in FCM algorithm, we initialize each cluster center by the center of a searched hypersphere. Our experimental results show that the proposed initializing scheme has higher probabilities of finding the global or near global optimal solutions than the traditional FCM algorithm.

• 인터넷정보학회논문지
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• 제12권2호
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• pp.63-73
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• 2011

일반적으로 기존 검색엔진은 다수 사용자의 동일한 질의에 대하여 일률적으로 같은 검색 결과를 제공하는데, 이는 사용자 개인의 특성을 고려하지 않는 단점을 가진다. 이를 극복하기 위해서 사용자가 가지고 있는 검색 의도를 파악하여 그에 부합하는 결과를 제공하는 개인화 검색이 필요하다. 본 논문에서는 사용자 프로파일 기반 개인화 검색을 위한 시스템을 제안한다. 본 시스템에서는 개인화 검색을 이루기 위해 개념 네트워크 형태의 사용자 프로파일을 구성하며, 이는 사용자가 과거에 질의했던 질의어와 탐색했던 웹문서를 분석하여 자동 생성된다. 그리고 사용자가 웹문서에 대해 태그를 지정한 폭소노미 데이터를 이용하여, 개념 네트워크를 확장함으로써 개념 네트워크의 정확성을 더욱 높일 수 있다. 이 개념 네트워크를 이용하여 사용자가 부여한 질의어를 확장시킬 수 있을 뿐만 아니라, 검색결과의 중첩도를 고려하여 사용자별 검색 결과의 순위를 재산정 함으로써 개인의 특성을 반영한 검색 결과를 제공할 수 있다.

• 한국전자거래학회지
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• 제11권3호
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• pp.35-51
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• 2006

정보의 시각화는 정보의 직관적 이해를 위해 중요한 역할을 하며, 다양한 응용영역에서 해당 환경의 특징에 맞추어 활용되고 있다. 본 논문에서는 전자상거래에서 상품을 효과적으로 검색하여 보여주기 위해서는 기존의 방식이 아닌 상품 정보의 특색에 맞는 검색 방식과 시각화 기법이 필요하다고 판단하여, 기존의 MapNet이나 클러스터맵 등의 기술을 반영한 상품 검색 비주얼라이제이션 기법을 소개한다. 상품 카테고리 검색과 속성 검색의 분리를 통해 검색조건에 명확한 시맨틱 부여를 가능하게 하고, 사용자에게 검색 결과를 평가하고 재검색을 수행할 수 있게 한다. 결과 평가는 원하는 결과를 얻지 못했을 경우 사용자가 질의어를 재작성하여 최적의 결과를 찾을 수 있게 한다.

• PNF and Movement
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• 제14권1호
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• pp.59-65
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• 2016

Purpose: The purpose of this study was to review articles in order to establish optimal contraction intensity and duration in the performance of relaxation techniques for maximal increase in range of motion. Methods: The Cochrane, EBSCO, Embase, Medline, ProQuest, PubMed, ScienceDirect, and Scopus databases were used to search articles from 1990 to January 2016. The search terms were "contract relax," "hold relax," "muscle energy technique (MET)," and "proprioceptive neuromuscular facilitation (PNF) stretching." Only experimental human studies (randomized controlled trials) that compared the effects of varying intensity and duration of isometric contraction were included. Non-English language and unpublished studies were excluded. Results: A total of 2,156 articles were initially identified, with only five eventually meeting the inclusion and exclusion criteria. Three studies compared the effects of varying intensity in isometric contraction and two studies compared the effects of varying duration in isometric contraction with regard to range of motion (ROM). Two articles suggested that submaximal voluntary isometric contraction was more effective than maximum voluntary isometric contraction (MVIC) in the improvement of ROM. One article showed that a longer contraction time led to greater increases in ROM. Conclusion: Submaximal voluntary isometric contraction was recommended during contract-relax exercises in healthy people. Lack of evidence makes it difficult to suggest the optimal duration of isometric contraction during relaxation techniques. For future research, high-quality evidence will be needed to establish the optimal contraction intensity for maximum improvement of ROM.

• International Journal of Computer Science & Network Security
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• 제21권1호
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• pp.40-48
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• 2021

Content-Based Image Retrieval (CBIR) system plays a vital role to retrieve the relevant images as per the user perception from the huge database is a challenging task. Images are represented is to employ a combination of low-level features as per their visual content to form a feature vector. To reduce the search time of a large database while retrieving images, a novel image retrieval technique based on feature dimensionality reduction is being proposed with the exploit of metaheuristic optimization techniques based on Genetic Algorithm (GA), Extended Binary Cuckoo Search (EBCS) and Whale Optimization Algorithm (WOA). Each image in the database is indexed using a feature vector comprising of fuzzified based color histogram descriptor for color and Median binary pattern were derived in the color space from HSI for texture feature variants respectively. Finally, results are being compared in terms of Precision, Recall, F-measure, Accuracy, and error rate with benchmark classification algorithms (Linear discriminant analysis, CatBoost, Extra Trees, Random Forest, Naive Bayes, light gradient boosting, Extreme gradient boosting, k-NN, and Ridge) to validate the efficiency of the proposed approach. Finally, a ranking of the techniques using TOPSIS has been considered choosing the best feature selection technique based on different model parameters.