• Atmosphere
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• v.17 no.1
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• pp.45-53
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• 2007

In order to investigate the impacts of heat wave on human health, cluster analysis of meteorological elements (e.g., temperature, dewpoint, sea level pressure, visibility, cloud amount, and wind components) for identifying offensive synoptic air masses is employed. Meteorological data at Seoul during the past 30 years are used. The daily death data at Seoul are also employed. Occurrence frequency of heat waves which is defined by daily maximum temperature greater than the threshold temperature (i.e., $31.2^{\circ}C$) was analyzed. The result shows that the frequency and duration of heat waves at Seoul are increasing during the past 30 years. In addition, the increasing trend of the frequency and duration clearly appears in late spring and early autumn as well as summer. Factor analysis shows that 65.1% of the total variance can be explained by 4 components which are linearly independent. Eight clusters (or synoptic air masses) were classified and found to be optimal for representing the summertime air masses at Seoul, Korea. The results exhibit that cluster-mean values of meteorological variables of an offensive air mass (or cluster) are closely correlated with the observed and standardized deaths.

• Journal of the Korean Society of Costume
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• v.36
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• pp.43-52
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• 1998

This study was to analyze properties of the foot form through a development figure of the surface area by factor analysis, cluster analysis, and reglation analysis. This study was performed 71 college women between 19 adn 23 years old residing in Pusan urban area. The result was as follows; 1. There are four factors selected by factor analysis. The 1st factor signifies the surface area of the toe. The 2nd factor signifies the surface area between Metatarsal circumfer-ence and Tarsal circumference. The 3rd factor signifies the surface area between Toe circumference and Metatarsal circumference. The 4th factor signifies the surface area between Heel-ankle circumference. 2. There are three clusters selected by fast cluster. Cluster 1 : The foot size, most parts of foot surface area and total foot surface area are relatively small to other clusters, but the surface area between Metatarsal circumference and Tarsal circumference is relatively large to other clusters. Cluster 2 : The foot size, all parts of foot surface area and total foot surface area are relatively large to other clusters as Cluster 1, but the surface area of the sole of the heel and the ankle is relatively large to other clusters. 3. Total surface area of the foot=-274.94+24.01* Foot lengh+9.28*Metatarsal circumference.

• Journal of the Korean Data and Information Science Society
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• v.24 no.4
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• pp.783-791
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• 2013

There are sixteen indicators of "College Information" found on the website of College Information Disclosure Center. Among these indicators, the current study examined an enrollment rate and an employment rate based on health insurance coverage, and focused on twenty-four universities in Daegu and Gyeongbuk area. The universities were classified into groups by the enrollment rate and employment rate. This study investigated the characteristics pertaining to those different groups. Hierarchical cluster analysis and support vector cluster analysis were conducted in order to analyze the characteristics of the groups statistically.

• Journal of Industrial Convergence
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• v.19 no.4
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• pp.9-15
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• 2021

The purpose of the study is to find out the difference between high school students' hopes and the school happiness of each cluster of grits. Method: 282 high students' responses were analyzed through correlation analysis and cluster analysis. Results: First, There is a positive correlation between hope and grit and school happiness. Second, Hope and Grit appeared in four clusters. School happiness had the highest "high psychological capital" group and the lowest "low psychological capital. Conclusion: It was discussed that the agency thinking and effort perseverance of grit should be reflected in the curriculum of general high schools. In addition, we propose to develop questionnaires for practical measurements.

• Journal of Intelligence and Information Systems
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• v.7 no.2
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• pp.35-49
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• 2001

Over the years, cluster analysis has become a popular tool for marketing and segmentation researchers. There are various methods for cluster analysis. Among them, K-means partitioning cluster analysis is the most popular segmentation method. However, because the cluster analysis is very sensitive to the initial configurations of the data set at hand, it becomes an important issue to select an appropriate starting configuration that is comparable with the clustering of the whole data so as to improve the reliability of the clustering results. Many programs for K-mean cluster analysis employ various methods to choose the initial seeds and compute the centroids of clusters. In this paper, we suggest a methodology to evaluate various clustering programs. Furthermore, to explore the usability of the methodology, we evaluate four clustering programs by using the methodology.

• Journal of the Korean Dietetic Association
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• v.19 no.1
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• pp.82-94
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• 2013

The purposes of this study were to measure the service mind and customer orientation of employees and to identify the effect of service mind on customer orientation in elementary school foodservices. The questionnaires were distributed to foodservice employees of the 19 elementary schools, but collected from 12 schools in Gwangju, Gyeonggi. The statistical data analysis was completed using SPSS (ver. 18.0) for the independent sample t-test, ANOVA, Cronbach's alpha, principal component analysis, hierarchical & K-means cluster analysis, Pearson' correlation analysis, and multiple regression analysis. Foodservice employees highly rated their service mind (3.94 out of 5 points), especially their perceptions on the importance of service (4.13 points). The effort to provide service was significantly different depending on the serving place (P<0.05). Employees had a high level of customer orientation (4.02 points), which was significantly influenced by age, position, or career (P<0.05), and cook license (P<0.01). As a result of cluster analysis for service mind, employees were divided into two groups: a low-service mind group (cluster 1) and a high-service mind group (cluster 2). Cluster 2 had a significantly higher overall customer orientation than cluster 1 (P<0.001). The pride in providing services (${\beta}$=0.390, P<0.01) and the perception of the importance of services (${\beta}$=0.297, P<0.05) showed a significant and positive effect on customer orientation.

• Journal of Soil and Groundwater Environment
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• v.27 no.6
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• pp.22-36
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• 2022

Water resources in Jeju Island are dependent virtually entirely on groundwater. For groundwater resources, drought damage can cause environmental and economic losses because it progresses slowly and occurs for a long time in a large area. Therefore, this study quantitatively evaluated groundwater level fluctuations using principal component and cluster analyses for 42 monitoring wells in Jeju Island, and further identified the types of groundwater fluctuations caused by drought. As a result of principal component analysis for the monthly average groundwater level during 2005-2019 and the daily average groundwater level during the dry season, it was found that the first three principal components account for most of the variance 74.5-93.5% of the total data. In the cluster analysis using these three principal components, most of wells belong to Cluster 1, and seasonal characteristics have a significant impact on groundwater fluctuations. However, wells belonging to Cluster 2 with high factor loadings of components 2 and 3 affected by groundwater pumping, tide levels, and nearby surface water are mainly distributed on the west coast. Based on these results, it is expected that groundwater in the western area will be more vulnerable to saltwater intrusion and groundwater depletion caused by drought.

• Korean Journal of Agricultural Science
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• v.43 no.1
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• pp.40-51
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• 2016

This study analyzed settlement condition changes of Chungcheong region's mountain area during 10 years, from 2001 to 2012. We performed factor analysis and cluster analysis of data from the 'Census for Mountain Area' carried out by the Korea Forest Service in 2001 and 2012. Factors 1, 2, 3, and 4 represent 'the superiority of non-agricultural income', 'the industrialized mountainous area', 'residential conveniences and benefits', and 'the use of forest resources', respectively. Clusters 1, 2, 3, 4, and 5 are categorized as 'non-agricultural income', 'various mass social functions', 'production of forest products', 'industrialized mountainous region', and 'ordinary mountain region', respectively. We suggest that cluster 1 has potential for development and should be promoted as a possible tourist attraction by digging up geographically unique themes. Cluster 2 has great potential for development and needs planned management through the maintenance or expansion of existing infrastructure. Cluster 3 has potential for development with various high value added industries uncovered. Cluster 4 shows vitality as it holds plenty of more job opportunities than other regions. Cluster 5 is deteriorating as a mountainous region because of an aging population, and it urgently demands development. For a decade, 45 of the 60 regions belonged to a single category, which are now differentiated broadly into two types: Firstly, deterioration changes to potential development and Secondly, vitality is differentiated into potential development and deterioration.

• Journal of the Economic Geographical Society of Korea
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• v.15 no.4
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• pp.515-533
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• 2012

Industrial cluster is adopted as a key policy for the development of regional and national economies in many developed or under-developing countries. The industrial cluster is basically concerned with knowledge sharing and exchanges among diverse functions such as firms, research institutions, and universities in a regional or innovation-network context. Therefore, activities to promote knowledge sharing and exchanges in an industrial cluster become very important activities to reach to the original purpose of an industrial cluster. In this study, factors affecting performance of those activities to promote knowledge sharing and exchanges in an industrial cluster are defined and the effects are examined through empirical study. For this research, surveys on enterprisers and employees in industrial cluster were conducted and statistical analysis methods such as correlation analysis, multiple regression analysis, and canonical correlation analysis were adopted for analyses.

• Journal of Preventive Medicine and Public Health
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• v.30 no.1 s.56
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• pp.181-193
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• 1997

The purpose of this study was to identify population subgroups with similar patterns of diet quality, physical activity, alcohol consumption and cigarette smoking of Korean. The cluster analysis was conducted using the data from Korea National Health Survey(KNHS) in 1995, which consisted of 5,805 persons. We identified six health behavior typologies : 32.9% of the sample had a good diet but sedentary activity level(good diet lifestyle), 7.2% had high activity level but less diet quality(fitness lifestyle). Individuals in the passive lifestyle cluster(39.1%) had no active health promoting activities but tended to avoid risk taking health behavior such as cigarette smoking and alcohol drinking. 1.1% of the sample were in a drinking cluster, 17.2% in a smoking cluster and 2.5% had a hedonic lifestyle characterized by heavy drinking and smoking. The other characteristics of these lifestyle clusters could be presented by demographic and socioeconomic factors.