• Industrial Engineering and Management Systems
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• 제8권1호
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• pp.22-28
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• 2009

We consider facility layout problems, where mn facility units are assigned into mn cells. These cells are arranged into a rectangular pattern with m rows and n columns. In order to solve this cell type facility layout problem, many approximation algorithms with improved local search methods were studied because it was quite difficult to find exact optimum of such problem in case of large size problem. In this paper, new algorithms based on Simulated Annealing (SA) method with two neighborhood generation methods are proposed. The new neighborhood generation method adopts the exchanging operation of facility units in accordance with adjacent preference. For evaluating the performance of the neighborhood generation method, three algorithms, previous SA algorithm with random 2-opt neighborhood generation method, the SA-based algorithm with the new neighborhood generation method (SA1) and the SA-based algorithm with probabilistic selection of random 2-opt and the new neighborhood generation method (SA2), are developed and compared by experiment of solving same example problem. In case of numeric examples with problem type 1 (the optimum layout is given), SA1 algorithm could find excellent layout than other algorithms. However, in case of problem type 2 (random-prepared and optimum-unknown problem), SA2 was excellent more than other algorithms.

• 대한음성학회지:말소리
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• 제67호
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• pp.79-102
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• 2008

In this paper, we investigate the relation between Bayes factor and likelihood ratio test (LRT) approaches and apply the neighborhood information of Bayes factor to building an alternate hypothesis model of the LRT system. To consider the neighborhood approaches, we contemplate a distance measure between models and algorithms to be applied. We also evaluate several methods to improve performance of utterance verification using neighborhood information. Among these methods, the system which adopts anti-models built by collecting mixtures of neighborhood models obtains maximum error rate reduction of 17% compared to the baseline, linear and weighted combination of neighborhood models.

• 한국멀티미디어학회논문지
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• 제18권6호
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• pp.691-700
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• 2015

Here, we present a new framework for histogram equalization in which both local and global contrasts are enhanced using neighborhood metrics. When checking neighborhood information, filters can simultaneously improve image quality. Filters are chosen depending on image properties, such as noise removal and smoothing. Our experimental results confirmed that this does not increase the computational cost because the filtering process is done by our proposed arrangement of making the histogram while checking neighborhood metrics simultaneously. If the two methods, i.e., histogram equalization and filtering, are performed sequentially, the first method uses the original image data and next method uses the data altered by the first. With combined histogram equalization and filtering, the original data can be used for both methods. The proposed method is fully automated and any spatial neighborhood filter type and size can be used. Our experiments confirmed that the proposed method is more effective than other similar techniques reported previously.

• 한국산업정보학회논문지
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• 제21권6호
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• pp.13-21
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• 2016

특징선택은 데이터 마이닝, 기계학습 분야에서 가장 중요한 이슈 중 하나로, 원본 데이터에서 가장 좋은 분류 성능을 보여줄 수 있는 특징들을 찾아내는 방법이다. 본 논문에서는 정보 입자성을 기반으로 한 neighborhood 러프집합 모델을 이용한 특징선택 방법을 제안한다. 제안된 방법의 효과성은 5,252명의 유방 초음파 영상으로부터 추출된 298가지의 특징들 중에서 유방 종양의 진단과 관련된 유용한 특징들을 선택하는 문제에 적용되었다. 실험결과 19가지의 진단적 특징을 찾을 수 있었고, 이때에 평균 분류 정확성은 97.6%를 보였다.

• 한국정보과학회:학술대회논문집
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• 한국정보과학회 2007년도 가을 학술발표논문집 Vol.34 No.2 (C)
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• pp.428-432
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• 2007

We present a novel method for determining k nearest neighbors, which accurately recognizes the underlying clusters in a data set. To this end, we introduce the "tiling neighborhood" which is constructed by tiling a number of small local circles rather than a single circle, as existing neighborhood schemes do. Then we formulate the problem of determining the tiling neighborhood as a minimax optimization, leading to an efficient message passing algorithm. For several real data sets, our method outperformed the k-nearest neighbor method. The results suggest that our method can be an alternative to existing for general classification tasks, especially for data sets which have many missing values.

• 한국전자통신학회논문지
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• 제16권3호
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• pp.533-540
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• 2021

시스템의 성능을 평가하기 위하여 1차원 3-이웃 셀룰라 오토마타(Cellular Automata, 이하 CA) 기반의 의사 난수 생성기가 여러 분야에서 많이 응용되고 있다. 보다 더 효과적인 키 수열 생성을 위해 2차원 CA와 1차원 5-이웃 CA가 응용되었으나, 주어진 특성 다항식에 대응하는 대칭 1차원 5-이웃 CA를 설계하는 것은 매우 어려운 문제이다. 이를 해결하기 위해 특성 다항식의 점화식을 이용한 합성 방법, Krylov 행렬을 이용한 합성 방법과 같이 1차원 5-이웃 CA 합성에 관한 연구들이 진행되었다. 그러나 여전히 비선형 방정식을 풀어야 하는 문제점이 있었다. 이러한 문제점을 해결하기 위해, 최근 90/150 CA의 전이 행렬과 블록행렬을 이용한 1차원 5-이웃 CA 합성 방법이 제안되었다. 본 논문에서는 제안된 알고리즘의 이론적인 과정을 상세히 기술하고 그 알고리즘을 이용하여 높은 차수의 원시 다항식에 대응하는 대칭 1차원 5-이웃 CA를 구한다.

• Journal of Preventive Medicine and Public Health
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• 제42권4호
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• pp.215-222
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• 2009

Objectives : Vigorous physical activity is a well-known method to promote people s health. This research aims to investigate whether perceived neighborhood characteristics affect vigorous physical activity among adult Seoul residents (aged 19 to 64). Methods : Utilizing the 2005 Seoul Citizens Health Indicators Survey data, this study estimates the probability of vigorous physical activity. Particular attention is given to the effects of three perceived neighborhood characteristics satisfaction with relationship to the neighborhood, satisfaction with park and recreational facilities, and satisfaction with public security). Logistic regression models are analyzed separately by gender for the parameter estimation. Results : Vigorous physical activity is positively associated with three perceived neighborhood characteristics for women, while neither significant nor substantive association is found for men. Conclusions : As vigorous physical activity among Seoul citizens is differentially affected by perceived neighborhood characteristics and by gender, a different approach will be needed to increase vigorous physical activity of men and women in Seoul.

• Spatial Information Research
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• 제10권2호
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• pp.215-232
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• 2002

본 연구는 근린유흥시설의 분포를 나타내는 헤도닉 모델의 근린변수가 지리정보시스템의 공간분석기능을 충분히 이용하여 측정되었을 경우, 그렇지 않을 경우에 비해 해당변수를 포함하는 헤도닉 모델의 통계적 질을 향상시킬 수 있는 가를 평가하고 있다. 평가결과는 해당변수가 지리정보시스템의 공간분석기능을 충분히 이용하여 측정되었을 경우가 헤도닉 모델의 설명력측면에서 우월함을 보이고 있다. 본 연구결과는 지리정보시스템이 단순한 직선거리를 추정하는 것 이상으로 헤도닉 모델의 질을 향상시킬 수 있는 잠재력을 가지고 있다는 것을 보이고 있으며 주택시장의 행태를 설명하는 이론적으로 타당한 근린변수의 측정을 위해 보다 적극적으로 이용되어야 함을 실증적으로 보이고 있다.

• KIEAE Journal
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• 제13권3호
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• pp.21-26
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• 2013

Recently, as the concern over environmental problem has been serious all over the world, carbon has become a key issue to mitigate the problem. In the field of Architecture, various sustainable assessment systems and LCCO2 assessment strategies have been developed, guiding low carbon building while planning. However, assessment system for low carbon neighborhood, which can be more efficient strategy, is still in the stage of research. In this paper, as a research for low carbon assessment system and planning guideline for neighborhood, scope meeting domestic condition has been set and sustainable assessment system for neighborhood, which is similar to low carbon concept, have been compared. LEED-Neighborhood Development, BREEAM-Communities, CASBEE-Urban Development, and GBCC-Apartment Houses were used for comparison. As a result, it is found that those systems has many differences in judging system, aggregating method, scope of evaluation, and relations with a building assessment system. The concern about carbon is not insufficient yet. Finally, assessment system for low carbon neighborhood, which is not only for establishing the plan, but also for giving guideline at the very first state of the plan, should be developed as fast as passible. With the result of this paper, establishment of assessment criteria and the way to measure quantitative $CO_2$ should be studied forward.

• 한국멀티미디어학회논문지
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• 제11권6호
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• pp.737-745
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• 2008

In this paper, a novel neighborhood metric of histogram equalization (HE) algorithm for contrast enhancement is presented. We present a refinement of HE using neighborhood metrics with a general framework which orders pixels based on a sequence of sorting functions which uses both global and local information to remap the image greylevels. We tested a novel sorting key with the suggestion of using the original image greylevel as the primary key and a novel neighborhood distinction metric as the secondary key, and compared HE using proposed distinction metric and other HE methods such as global histogram equalization (GHE), HE using voting metric and HE using contrast difference metric. We found that our method can preserve advantages of other metrics, while reducing drawbacks of them and avoiding undesirable over-enhancement that can occur with local histogram equalization (LHE) and other methods.