• The Korean Journal of Applied Statistics
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• v.20 no.1
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• pp.23-38
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• 2007

Corporations adopt a segmentation depends on the existence of target variables, in general. In this paper, for the case of no target variables, a strategy through segmentation is proposed for corporations having a special status based on the management index. In case of segmentation using cluster analysis, however, if one classify according to many variables then he will be in face of difficulties in characterizing. Therefore, after extracting representative factors by factor analysis, a segmentation method through 2 step cluster analysis is employed on the basis of these representative factors. As a result, six segmentation groups are found and the resulting strategy is proposed which strengthens prominent factors and makes up defective factors for each group.

• Korean Journal of Environment and Ecology
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• v.9 no.2
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• pp.156-165
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• 1996

To investigate the forest structure and to suggest the management of vegetation landscape in Noinbong area, Pdaesan National Pa, twelve plots were set up and surveyed. According to the acalysis of classification by TWINSPAN, the community was divided by two groups of Carpinus laxiflora - Quercus mongolica community and the other is Betula costata - schmidtii - C. laxiflora community. It was found out that the successional stage of Noinbong forests was climax and introduced-climax by the analysis of species structure, similarity index and species diversity. The number of individuals was about 120~130 and species was 17 per 100m$^{2}$. Through the analysis of basal area and DBH class distribution, it was estimated that C. laxiflora, B. costata, and B. schmidtii will be clmax species instead of Q. mongolica in tree layer, and in the subtree layer, Acer pseudo-sieboldianum will be dominant species.

• Journal of the Korean Data and Information Science Society
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• v.20 no.3
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• pp.551-562
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• 2009

In this paper, I would present a using method for The Fishing Operation Information(FOI) of National Federation of Fisheries Cooperatives(NFFC) through the availabilities analysis and put out the similarities by the section of the sea through classifying characteristics of fishing patterns by their locations. As a result, although the catch of FOI is nothing more than 33% level to National Fishery Production Statistics(NFPS), FOI data is useful in understanding the patterns of fishing operation by the location because both patterns and correlation were very similar in the usability analysis, comparing the FOI data with NFPS. So I classified optimal clusters for catch, the number of fishing days and the number of fishing vessels through 2 step cluster analysis by the big marine zone and divided fishing patterns.

• Korean Journal of Remote Sensing
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• v.19 no.2
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• pp.135-147
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• 2003

This study used the multistage hierarchical clustering image classification to analyze the satellite images for the land-cover types of an area in the Korean peninsula. The multistage algorithm consists of two stages. The first stage performs region-growing segmentation by employing a hierarchical clustering procedure with the restriction that pixels in a cluster must be spatially contiguous, and finally the whole image space is segmented into sub-regions where adjacent regions have different physical properties. Without spatial constraints for merging, the second stage clusters the segments resulting from the previous stage. The image classification of hierarchical clustering, which merges step-by step two small groups into one large one based on the hierarchical structure of digital imagery, generates a hierarchical tree of the relation between the classified regions. The experimental results show that the hierarchical tree has the detailed information on the hierarchical structure of land-use and more detailed spectral information is required for the correct analysis of land-cover types.

• Science of Emotion and Sensibility
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• v.3 no.2
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• pp.67-74
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• 2000

본 연구는 주거환경에 대한 시각 감성을 대표하는 어휘를 선발하기 위해 수행되었다. 어휘수집의 첫 단계에서는 주거환경 중 시각 환경에 대한 감성을 표현하는 어휘 235개를 수집하였다. 두 번째 단계에서는 수집된 어휘를 다른 피험자들에게 제시하여 주거 환경의 분위기를 나타내는 어휘 로서 적절함의 정도를 7점 척도로 표시하도록 하여 매우 적절하다고 판단된 24개의 어휘를 선발하였다. 세 번째 단계에서는 이들 어휘를 무선 적으로 두 개씩 짝을 지어 두 단어가 유사한 정도를 7점 척도로 평가하도록 하였다. 이 설문으로부터 나온 데이터에 대해 요인분석, 군집분석, 다차원분석을 실시하여 시각적 주거환경에 대한 9개의 감성어휘를 추출하였다. 이와 함께 최종 단계에서 연구자들이 400여장의 실물 사진 열람을 통해 추출된 9개의 감성 어휘가 실제 시각적 주거환경을 나타내는 데에 적함한지를 다시 한번 검증하여 다음과 같은 10개의 어휘를 선발하였다. ‘안락한’, ‘개방적인’, ‘세련된’, ‘경쾌한’, ‘개성적인’, ‘단순한’, ‘화려한’, ‘중후한’, ‘고풍스로운’, ‘전원적인’.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.43 no.1
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• pp.91-98
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• 2023

Since risks occurring in construction projects can have a significant impact on schedules and costs, there have been many studies on this topic. However, risk analysis is often limited to only certain construction situations,and experience-dependent decision-making is therefore mainly performed. Data-based analyses have only been partially applied to safety and contract documents. Therefore, in this study, cluster analysis and a Word2Vec algorithm were applied to formal documents that contain important elements for contractors or clients. An initial classification of document content into six types was performed through cluster analysis, and 157 occurrence types were subdivided through application of the Word2Vec algorithm. The derived terms were re-classified into five categories and reviewed as to whether the terms could develop into potential construction risk factors. Identifying potential construction risk factors will be helpful as basic data for process management in the construction industry.

• Proceedings of the Korea Water Resources Association Conference
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• 2018.05a
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• pp.112-112
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• 2018

최근 이상기후로 인한 국부적인 혹은 광역적인 가뭄이 빈번하게 발생하고 있는 추세이며 발생횟수 뿐 아니라 가뭄 심도 및 지속기간이 과거보다 크게 증가하여 그에 따른 피해가 커질 것으로 예측되고 있다. 특히, 2014~2015년도의 유례없는 가뭄으로 인해 저수지 용수공급이 제한되면서 많은 농가들이 피해를 입었다. 본 연구의 목적은 전국 농업용 저수지를 대상으로 기상청 3개월 예보자료를 활용 할 수 있는 농업용 저수지 저수율 다중선형 회귀 모형을 개발하여 저수율 전망정보를 생산하는 것이다. 본 연구에서는 전국에 적용 가능한 저수율 다중선형 회귀 모형개발을 위해 5개의 기상요소(강수량, 최고기온, 최저기온, 평균기온, 평균풍속)와 관측 저수지 저수율을 활용했다. 기상자료는 2002년부터 2017년까지의 기상청 63개 지상관측소로부터 기상관측자료를 수집하였다. 본 연구에서는 저수율 전망 단계를 세 단계로 나누었다. 첫 번째 단계로 농어촌공사에서 전국 511개 용수구역을 대상으로 군집분석 및 의사결정나무 분석을 통해 제시한 65개 대표저수지를 대상으로 기상자료 및 관측 저수율 자료를 이용하여 다중선형 회귀분석을 실시하였다. 수집한 기상요소와 저수율을 독립변수로 하여 월별 회귀식을 산정한 결과 결정계수($R^2$)는 0.51~0.95로 나타났다. 두 번째 단계로 대표저수지의 회귀분석 결과를 전국의 저수지로 확대하기 위해 나이브 베이즈 분류법을 적용하여 전국 3098개의 저수지를 65의 군집으로 분류하고 각각의 군집에 해당되는 월별 회귀식을 산정하였다. 마지막으로 전국 저수지로 산정된 회귀식과 농업 가뭄 예측을 위해 기상청의 GS5(Global Seasonal Forecasting System 5) 3개월 예보자료를 수집하여 회귀식에 적용해 2017년 전국 저수지의 3개월 저수율 전망정보를 생산하였다. 본 연구의 전국 저수지 군집결과 기반의 저수율 전망기술은 2017년도 관측 저수율과 비교한 결과 유의한 상관성을 나타냈으며 이 결과는 추후 농업용 저수지의 물 공급 및 농업가뭄 전망 자료로서 이용이 가능할 것으로 판단된다.

• Korean Security Journal
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• no.51
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• pp.293-313
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• 2017

The purpose of this study is to analyze the changes of regional clusters of national 16 areas on the assembly & demonstration in 2010 and 2015. The results of this study were as follows by using hierarchical cluster analysis. First, the regional clusters on the assembly & demonstration in 2010 were divided into three clusters in the first step: (1) Gwangju, Chungnam, Incheon, Chungbuk, Gyeongbuk, Daegu, Gangwon, Jeju, Daejeon, (2) Jeonnam, Gyeongnam, Busan, Jeonbuk, Ulsan, Gyeonggi, (3) Seoul. Second, the regional clusters on the assembly & demonstration in 2015 were divided into three clusters in the first step: (1) Ulsan, Gangwon, Chungbuk, Chungnam, Incheon, Gyeongbuk, Jeonnam, Gwangju, Jeju, Daegu, Daejeon, (2) Busan, Jeonbuk, Gyeongnam, (3) Seoul, Gyunggi. Third, The regional clusters on the assembly & demonstration were Busan, Jeonbuk, Gyeongnam of 'assembly & demonstration management area(labor related)', and Seoul, Gyeonggi of 'assembly & demonstration frequency areas' in 2015. This suggests that policing policies related to assembly & demonstration can be established and implemented flexibly in consideration of the degree of increase and decrease in assembly & demonstration by districts. Furthermore, it will be helpful to manage assembly & demonstration based on the 'police for human rights'.

• Korean Journal of Environment and Ecology
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• v.10 no.2
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• pp.283-296
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• 1997

To investigate the plant community structure in valley and suggest the management of Mational Park, fifty plots were set up and surveyed in Jujeongol Valley, Soraksan National Park. The classification by TWINSPAN and DCA ordination technique were applied to the study area in order to classify them into several groups based on woody plants. The dividing groups were Quercus mpnngolica - Q. variabilis - Pinus densiflora community, P. densiflora community, Carpinus laxiflora community, Q. serrata community. The ecological trends of tree species by DCA ordination technique and DBH class distribution analysis was like that Q. mongolica - Q. variabilis - P. densiflora community and P. densiflora community seems to be trended from P. densiflora community to Q. mongolica community. Q. serrata community seems to be trended from Q. serrata community to C. laxiflora community and C. laxiflora will be maintaimed stable state.

• Journal of Korea Port Economic Association
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• v.37 no.1
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• pp.31-70
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• 2021

The purpose of this paper is to measure the clustering change and analyze empirical results, and choose the clustering ports for Busan, Incheon, and Gwangyang ports by using Hierarchical clustering(single, complete, average, and centroid), Silhouette, and 2SCE[the Second Stage(Type II) cross-efficiency] matrix clustering models on Asian container ports over the period 2009-2018. The models have chosen number of cranes, depth, birth length, and total area as inputs and container TEU as output. The main empirical results are as follows. First, ranking order according to the efficiency increasing ratio during the 10 years analysis shows Silhouette(0.4052 up), Hierarchical clustering(0.3097 up), and 2SCE(0.1057 up). Second, according to empirical verification of the Silhouette and 2SCE models, 3 Korean ports should be clustered with ports like Busan Port[ Dubai, Hong Kong, and Tanjung Priok], and Incheon Port and Gwangyang Port are required to cluster with most ports. Third, in terms of the ASEAN, it would be good to cluster like Busan (Singapore), Incheon Port (Tanjung Priok, Tanjung Perak, Manila, Tanjung Pelpas, Leam Chanbang, and Bangkok), and Gwangyang Port(Tanjung Priok, Tanjung Perak, Port Kang, Tanjung Pelpas, Leam Chanbang, and Bangkok). Third, Wilcoxon's signed-ranks test of models shows that all P values are significant at an average level of 0.852. It means that the average efficiency figures and ranking orders of the models are matched each other. The policy implication is that port policy makers and port operation managers should select benchmarking ports by introducing the models used in this study into the clustering of ports, compare and analyze the port development and operation plans of their ports, and introduce and implement the parts which required benchmarking quickly.