• 한국안광학회지
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• 제20권4호
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• pp.405-414
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• 2015

목적: 안경원 고객에 대한 군집분석을 통하여 고객의 세분시장 특성을 분석하고, 이를 안경원 마케팅 전략에 유용한 지표로 삼을 수 있도록 하고자 한다. 방법: 2015년 3월 10일부터 3월 31일 사이에 서울 및 경기북부지역의 안경원을 방문한 고객을 대상으로 설문조사를 실시하였으며, SPSS v.10.0 통계 패키지 프로그램을 활용하여 분석하였다. 분석방법은 빈도분석, 가치관 변수에 대한 요인분석, 시장세분화를 위한 군집분석, 교차분석을 실시하였다. 결과: 가치관에 근거하여 시장을 세분화하였다. 마케팅 전략을 수립할 때 "중도가치 지향 집단", "고도가치 지향 집단", "고도가치 지향 비종교 집단"의 3가지 군집으로 고객을 분류하여 전략을 수립하는 것이 좋은 것으로 나타났다. 누진굴절력렌즈의 마케팅 전략은 "중도가치 지향 집단"에서 자영업자를 중심으로 하는 전략이 가장 중요한 것으로 나타났다. 결론: 군집분석을 통하여 시장을 세분화한 결과 3가지 군집으로 분류되었으며, 누진굴절력렌즈의 가장 중요한 고객은 "중도가치 지향 집단"에서 41세 이상의 자영업자임을 알 수 있었다.

• Environmental Engineering Research
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• 제20권3호
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• pp.285-289
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• 2015

Complicated and expensive seawater desalination technology is a big challenge in boron removal process. Conventional seawater desalination process of coagulation utilized for pre-treatment is difficult to remove boron. Boron can be removed more effectively in Reverse Osmosis (RO) process than any other processes. In this study, a coagulant with the name Mineral Cluster was examined its boron removal ability. Boron removal efficiency of Mineral Cluster depended on pH value and Mineral Cluster dosage. Desalination process combines the pre-treatment process with Mineral cluster diluted at the ratio of 1:2500 and the RO membrane process. The original sea water could be desalinated to drinking water quality, 1 mg/L, without any pH adjustments. Therefore, if the Mineral cluster is added without any other chemicals for adjusting pH, the desalination process would be much safer, efficient and economical.

• Communications for Statistical Applications and Methods
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• 제25권4호
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• pp.373-383
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• 2018

The spatial scan statistic is a widely used method to detect spatial clusters. The method imposes a large number of scanning windows with pre-defined shapes and varying sizes on the entire study region. The likelihood ratio test statistic comparing inside versus outside each window is then calculated and the window with the maximum value of test statistic becomes the most likely cluster. The results of cluster detection respond sensitively to the shape and the maximum size of scanning windows. The shape of scanning window has been extensively studied; however, there has been relatively little attention on the maximum scanning window size (MSWS) or maximum reported cluster size (MRCS). The Gini coefficient has recently been proposed by Han et al. (International Journal of Health Geographics, 15, 27, 2016) as a powerful tool to determine the optimal value of MRCS for the Poisson-based spatial scan statistic. In this paper, we apply the Gini coefficient to normal-based spatial scan statistics. Through a simulation study, we evaluate the performance of the proposed method. We illustrate the method using a real data example of female colorectal cancer incidence rates in South Korea for the year 2009.

• 전자공학회논문지CI
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• 제41권3호
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• pp.37-45
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• 2004

본 논문에서는 이동 에드-혹 네트워크에서 조합가중치 클러스터링 알고리즘을 적용하여 강건하고 신뢰성 있는 클러스터 기반의 그룹 멀티캐스트 방식을 제안한다. 에드-혹 네트워크는 고정된 통신 하부 구조의 도움 없이 이동 단말기로만 구성된 무선 네트워크이다. 제한된 대역폭과 높은 이동성으로 인하여 에드-혹 네트워크에서의 라우팅 프로토콜은 강건하고, 간단하면서 에너지 소비를 최소화하여야 한다. WCGM(Weighted Cluster Group Multicast)방식은 조합 가중치 다중 클러스터 기반 구조를 이용하고 기존의 FGMP(Forwarding Group Multicast Protocol)방식의 장점인 제한적인 플러딩에 의한 데이터 전달방식은 유지하면서 클러스터 헤드 선출 시 조합가중치를 적용한다. 이것은 안정적이며 강건한 데이터 전달 구조를 가지기 때문에 데이터 전달 구조를 유지하기 위한 오버헤드(Overhead)와 데이터 전달을 위한 오버헤드를 모두 줄이는 효과를 시뮬레이션을 통하여 검증하였다.

• Structural Engineering and Mechanics
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• 제72권4호
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• pp.469-477
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• 2019

The understanding of tool-rock interaction mechanism is of high essence for improving the rock breaking efficiency and optimizing the drilling parameters in mechanical rock breaking. In this study, the tool-rock interaction models of indentation and cutting are carried out by employing the discrete element method (DEM) to examine the rock failure modes of various brittleness rocks and critical indentation and cutting depths of the ductile to brittle failure mode transition. The results show that the cluster size and inter-cluster to intra-cluster bond strength ratio are the key factors which influence the UCS magnitude and the UCS to BTS ratio. The UCS to BTS strength ratio can be increased to a more realistic value using clustered rock model so that the characteristics of real rocks can be better represented. The critical indentation and cutting depth decrease with the brittleness of rock increases and the decreasing rate reduces dramatically against the brittleness value. This effort may lead to a better understanding of rock breaking mechanisms in mechanical excavation, and may contribute to the improvement in the design of rock excavation machines and the related parameters determination.

• 한국대기환경학회지
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• 제32권5호
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• pp.513-525
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• 2016

To propose an effective ensemble methods in predicting $PM_{10}$ concentration, six experiments were designed by different ensemble average methods (e.g., non-weighted, single weighted, and cluster weighted methods). The single weighted method was calculated the weighted value using both multiple regression analysis and singular value decomposition and the cluster weighted method was estimated the weighted value based on temperature, relative humidity, and wind component using multiple regression analysis. The effects of ensemble average methods were significantly better in weighted average than non-weight. The results of ensemble experiments using weighted average methods were distinguished according to methods calculating the weighted value. The single weighted average method using multiple regression analysis showed the highest accuracy for hourly $PM_{10}$ concentration, and the cluster weighted average method based on relative humidity showed the highest accuracy for daily mean $PM_{10}$ concentration. However, the result of ensemble spread analysis showed better reliability in the single weighted average method than the cluster weighted average method based on relative humidity. Thus, the single weighted average method was the most effective method in this study case.

• 가족자원경영과 정책
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• 제14권3호
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• pp.1-14
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• 2010

The purpose of this study was (1) to investigate the changes in consumer competencies according to the types of shopping value, (2) to reveal the effects of shopping value on consumer competencies. The subjects of this study were 266 university students dwelling in Seoul. A questionnaire was used as the survey method. The data was analyzed by Cronbach's alpha, frequencies, percentile, mean, factor analysis, K-mean cluster analysis, t-test, ANOVA and Duncan's multiple range tests, multiple linear regressions. Computations were conducted by SPSS WIN 12.0. The study produced the following results. First, college students can be categorized into 3 shopping values by K-means Cluster analysis of 13 items: the hedonic shopper (shopping value), the utilitarian shopper (shopping value) and the balanced shopper (shopping value). Second, there were significant differences in grades, satisfaction with life and shopping value. That is, grade 3and utilitarian shopping value group had a higher level of consumer competency. Third, the variable that influenced consumer competency was the utilitarian shopping value, influencing consumer attitude and consumer skill. These results imply that consumers should be constantly educated and that there needs to be a campaign to promote utilitarian shopping value.

• 한국지능시스템학회논문지
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• 제1권3호
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• pp.4-19
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• 1991

In this paper, we propose a fuzzy neural network pattern classifier utilizing fuzzy information. This system works without any a priori information about the number of clusters or cluster centers. It classifies each input according to the distance between the weights and the normalized input using Bezdek's [1] fuzzy membership value equation. This model returns the correct membership value for each input vector and find several cluster centers. Some experimental studies of comparison with other algorithms will be presented for sample data sets.

• Journal of Korea Trade
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• 제23권4호
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• pp.103-114
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• 2019

Purpose - This paper investigates the structure of exports across countries in terms of value added. Exports value added is examined under two categories, domestic and overseas. Using a statistical classification method by distance based on these two value added categories, this paper estimates the similarity of exports value added across countries including Korea. Design/methodology - The model of study is to employ a generalized distance function and then derive the Manhattan and Euclidean distances. The paper also performs cluster analysis using the Partitioning Around Medoids (PAM) and hierarchical methods to classify the 44 sample countries considered in this study. Findings - Our main findings are as follows. The 44 countries can be classified under 5 groups by their domestic and overseas value added in exports. Korea has a sandwich global value chains (GVCs) position between Japan, China, and Taiwan in the East Asian region. Originality/value - Existing papers point out the double counting problem of trade statistics as the intermediate goods trade across borders increases. This paper addresses the double counting problem by using the World Input-Output Table. The paper shows the need to explore the similarity of value added in exports structure across countries and investigate the GVCs position and role of each country.

• 한국의상디자인학회지
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• 제18권3호
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• pp.99-111
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• 2016

In order to use cosmetics brands SNS effectively and establish strategy, the purpose of this study is to provide consumer date. According to cosmetics consumption value groups, this study examined each cosmetics consumption value group's level of concern of three cosmetics brands SNS features, informativity, enjoyment and interactivity. For the data, questionnaire was collected by 198 women, and the data were measured by ANOVA, factor analysis, cluster analysis and Ducan test. According to cluster analysis cosmetics consumption value groups were divided into four groups, unconcern group, hedonic value pursuit group, function of brand value pursuit group, high concern group. The results of the study are as follows: First, high concern group thought highly of all cosmetics brands SNS features, including informativity, enjoyment and interactivity. In addition all consumer groups were concerned informativity rather then enjoyment and interactivity. Second, comparing with high concern group, other groups which include unconcern group, hedonic value pursuit group and function of brand value pursuit group were not concerned about cosmetics brands SNS features' enjoyment and interactivity. Except informativity, hedonic value pursuit group and unconcern group were more concerned interactivity than enjoyment. While, high concern group and function of brand value pursuit group were more concerned enjoyment than interactivity.