• Title/Summary/Keyword: cluster method

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Socioeconomic Differentials in Health and Health Related Behaviors: Findings from the Korea Youth Panel Survey (사회경제적 위치에 따른 청소년의 건강과 건강 관련 행태의 차이 : 한국청소년패널 조사 결과)

  • Cho, Sung-Il;Yang, Seung-Mi;Lee, Moo-Song;Khang, Young-Ho
    • Journal of Preventive Medicine and Public Health
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    • v.38 no.4
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    • pp.391-400
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    • 2005
  • Objective : This study examined the socioeconomic differentials for the health and health related behaviors among South Korean middle school students. Methods : A nationwide cross-sectional interview survey of 3,449 middle school second-grade students and their parents was conducted using a stratified multi-stage cluster sampling method. The response rate was 93.3%. The socioeconomic position indicators were based on self-reported information from the students and their parents: parental education, father's occupational class, monthly family income, out-of-pocket expenditure for education, housing ownership, educational expectations, educational performance and the perceived economic hardships. The outcome variables that were measured were also based on the self-reported information from the students. The health measures included self-rated health conditions, psychological or mental problems, the feelings of loneliness at school, the overall satisfaction of life and the perceived level of stress. The health related behaviors included were smoking, alcohol drinking, sexual intercourse, violence, bullying and verbal and physical abuse by parents. Results : Socioeconomic differences for the health and health related behaviors were found among the eighth grade boys and girls of South Korea. However, the pattern varied with gender, the socioeconomic position indicators and the outcome measures. The prevalence rates of the overall dissatisfaction with life for both genders differed according to most of the eight socioeconomic position indicators. All the health measures were significantly different according to the perceived economic hardship. However, the socioeconomic differences in the self-rated health conditions and the psychosocial or mental problems were not clear. The students having higher socioeconomic position tended to be a perpetrator of bullying while those students with lower socioeconomic position were more likely to be a victim. Conclusions : The perceived economic hardships predicted the health status among the eighth graders of South Korea. The overall satisfaction of life was associated with the socioeconomic position indicators. Further research efforts are needed to explore the mechanisms on how and why the socioeconomic position affects the health and health related behaviors in this age group.

The study of relationship of Security Service Company's Market Orientation and Business Performance (시큐리티기업의 시장지향성과 경영성과의 관계 연구)

  • Park, Ki-Beom
    • Korean Security Journal
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    • no.17
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    • pp.109-129
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    • 2008
  • The purpose of this study is to analyze the relationship of market orientation, and business performance in the security firms. To achieve the goal of the study, it has used various methods to study. First of all, it has carried out documentary surveys through literatures review on market orientation and business performance of the security firms, and practical researches side by side. In the documentary surveys, it has developed the framework of study and questionnaires based on the domestic and foreign books, theses, materials of public institutions, and other materials. In the practical researches, basing on the selected study models and hypotheses, it has selected 15 security companies which are located in Seoul, Gyeonggi and Chungcheong Provinces with the stratified cluster random sampling method. It has polled the employees of the security companies for about 2 months from 5 August to 10 October 2006, distributing 20$\sim$50 pieces per company. It has distributed 600 pieces and used 565 pieces for analysis excepting unfaithful 35 pieces. The collected questionnaires were analyzed by SPSSWIN 14.0 program. and The methods to analyze the materials were factor analysis, reliability analysis, correlation analysis, multiple regression analysis, and path analysis through regression analysis. The results obtained from the study using analysis methods above are as follows. Finally, market orientation influences on business performance. In other words, the higher market orientation is, the better financial and non financial outcomes are.

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Structural Evolution on Ag/Si(111) Ag/Si(111)√3X√3 with Adatom Coverage (흡착원자의 덮임율에 따른 Ag/Si(111)√3X√3의 구조 변화)

  • Jeong, Ho-Jin;Jeong, Suk-Min
    • Journal of the Korean Vacuum Society
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    • v.17 no.5
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    • pp.387-393
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    • 2008
  • Using a first-principles total-energy method, we investigate structural and energy changes on Ag/Si(111)$\sqrt{3}{\times}\sqrt{3}$($\sqrt{3}-Ag$ hereafter) as the number of the additional Ag adatoms increases. The Ag coverage varies from 0.02 to 0.14 ML. Most Ag adatoms occupy the ST site, which is the center of small triangles of the substrate Ag layer that is composed of small and large triangles. One of the interesting adsorption features is that the adatoms immerse below the substrate layer. The total energy calculations show that the clusters become the most stable when the number of Ag atoms is three. This three-Ag cluster becomes the building block of the $\sqrt{21}{\times}\sqrt{21}$ phase that shows a large surface conductivity. The simulated STM images show that the adatoms look dark in filled-state images while bright in empty-state images. This suggests that the adatoms donate their charge to the substrate. The simulated STM images agree well with the experimental images.

Copper Film Growth by Chemical Vapor Deposition: Influence of the Seeding Layer (ICB seeding에 의한 CVD Cu 박막의 증착 및 특성 분석)

  • Yoon, Kyoung-Ryul;Choi, Doo-Jin;Kim, Seok;Kim, Ki-Hwan;Koh, Seok-Keun
    • Korean Journal of Materials Research
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    • v.6 no.7
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    • pp.723-732
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    • 1996
  • Cu films were deposited by chemical wapor deposition on the as-received substrates (TiN/Si) and three kinds of Cu-seeded substrates (Cu/TiN/Si) which had seeding layer in the thick ness of 5 ${\AA}$ and 130 ${\AA}$ coated by ICB(Ionized Cluster Beam) method. The effect of Cu seeding layers on the growth rate, crystallinity, grain size uniformity and film adhesion strength of final CVD-Cu films was investigated by scanning eletron microscopy(SEM), X-ray diffractometry and scratch test. The growth rate was found to incresase somewhat in the case of ICB-seeding. The XRD patterns of the Cu films on the as-received substrate and ICB Cu-seeded substrates exhibited the diffraction peaks corresponding to FCC phase, but the peak intensity ratio($I_{111}/I_{200}$) of Cu films deposited on the ICB Cu-seeded substrates increased compared with that of Cu films on the as-received substrate. The resistivity of final Cu film on 40 ${\AA}$ seeded substrate was observed as the lowest value, 2.42 $\mu\Omega\cdot$cm compared with other Cu films. In adhesion test, as the seeding thickness increased from zero to 130 ${\AA}$, the adhesion strength increased from 21N to 27N.

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The Association of Dietary Patterns with Bone Mineral Density in Middle-aged Women: A Cohort of Korean Genome Epidemiology Study (중.장년기 여성의 식사패턴과 골밀도간의 연관성 연구: 한국인유전체역학조사사업 예방유전체 지역사회 코호트)

  • Park, Seon-Joo;Ahn, Youn-Jhin;Kim, Hyo-Mi;Joo, Seong-Eun;Oh, Kyung-Soo;Park, Chan
    • Korean Journal of Community Nutrition
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    • v.12 no.3
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    • pp.352-360
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    • 2007
  • Several nutrients are known to affect bone mineral density (BMD). However, these nutrients are combined with food intake and dietary patterns and little is known about the association of dietary patterns and BMD. The objective of this study was to investigate the association of dietary patterns with BMD in Korea Genome Epidemiology Study subjects. Among 2,884 women (40-69 yr) recruited at baseline study (2001), 861 subjects with BMD measurements at baseline and a 4-year follow up study (2005) completed the semi-quantitative food frequency questionnaire. BMD was measured by the Quantitative Ultrasound method. One hundred three food items were combined into 17 food groups and 4 dietary patterns were identified by factor analysis. Cluster analysis using factor score classified each subject into one of three dietary pattern groups named 'Rice and kimchi eating' (n = 617), 'Contented eating' (n = 124), and 'Healthy and light eating' (n = 120). The 'Healthy and light eating' group, characterized by higher intake of fruit, vegetables, fish, milk and dairy products, and younger age, more exercise, higher education, and higher income than other groups. The tibia BMD of the 'Healthy and light eating' group was higher than the other groups after adjusting for the age. After the adjustment for the age BMI and exercise, the 'Healthy and light eating' group showed significantly lower odds of tibia osteopenia/osteoporosis risk compared to the 'Rice and kimchi eating' group both at the baseline [OR(95% CI) : 0.50(0.30-0.84)] and follow-up [OR(95% CI) : 0.59(0.36-0.97)] examinations. The dietary pattern with low calorie and high intakes of fruit, vegetables, fish, milk and dairy products may have beneficial effects on BMD in middle-aged women.

The Chemotoxonoic Relationship of Vibrio cholerae non-O1 by Fatty Acid Compositions (지방산 조성에 의한 vibrio cholerae non-O1의 화학분류학적 관계)

  • 성희경;이원재;장동성
    • Journal of Food Hygiene and Safety
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    • v.13 no.2
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    • pp.149-154
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    • 1998
  • The authors attempted utilization of fatty acid composition of vibrios as a tool for identification of the strains. Fatty acid of 49 strains of Vibrio cholerae non-O1, V. cholerae O1, V mimicus, V vulinificus and V parahaemolyticus was analyzed by gas-liquid chromatography column. According to the statistical analysis of the fatty acid data, the relationship between the Vibrio species and serotypes of the strains was discussed. Forty one kinds of fatty acid were detected from the tested strains and 35 kinds of fatty acids among the detected fatty acids were significant factors to identify the vibrios. The predominant fatty acids were 16:0, 16:1 cis 9, 18:1 trans 9/6/cis 11 and 15:0 iso 2OH/16:1 cis 9 as above about 20% in total. Fatty acid compositions of the Vibrio species were an important factor in identifying their subspecies either predominant fatty acids or minor ones. According to the analysed results by a conventional statistical processing method (UPGMA) and prepared dendrogram, V cholerae non-01 had more closer relationship with V. mimicus compared with V. cholerae 01. Moreover, the distribution of hydroxy acid was a significant factor for identifying V cholerae subspecies. Comprising all the 10 serotypes detected from V. cholerae non-01 examined such as O2, O5, O8, O10, O14, O27, O37, O39, O45 and O69, we could group them into seven subspecies by cluster analysis with the similarity value of fatty acid composition as above 92%. It means that there is a significant relationship between serotypes and fatty acid composition of V. cholerae. These results indicated that numerical analysis of fatty acid composition data of V cholerae non-01 could classifY them into subspecies, and also which may provide a useful epidemiologic information or a basis for further analysis such as PCR and DNA probe analysis.

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Designing mobile personal assistant agent based on users' experience and their position information (위치정보 및 사용자 경험을 반영하는 모바일 PA에이전트의 설계)

  • Kang, Shin-Bong;Noh, Sang-Uk
    • Journal of Internet Computing and Services
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    • v.12 no.1
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    • pp.99-110
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    • 2011
  • Mobile environments rapidly changing and digital convergence widely employed, mobile devices including smart phones have been playing a critical role that changes users' lifestyle in the areas of entertainments, businesses and information services. The various services using mobile devices are developing to meet the personal needs of users in the mobile environments. Especially, an LBS (Location-Based Service) is combined with other services and contents such as augmented reality, mobile SNS (Social Network Service), games, and searching, which can provide convenient and useful services to mobile users. In this paper, we design and implement the prototype of mobile personal assistant (PA) agents. Our personal assistant agent helps users do some tasks by hiding the complexity of difficult tasks, performing tasks on behalf of the users, and reflecting the preferences of users. To identify user's preferences and provide personalized services, clustering and classification algorithms of data mining are applied. The clusters of the log data using clustering algorithms are made by measuring the dissimilarity between two objects based on usage patterns. The classification algorithms produce user profiles within each cluster, which make it possible for PA agents to provide users with personalized services and contents. In the experiment, we measured the classification accuracy of user model clustered using clustering algorithms. It turned out that the classification accuracy using our method was increased by 17.42%, compared with that using other clustering algorithms.

Geometric Analysis of Fracture System and Suggestion of a Modified RMR on Volcanic Rocks in the Vicinity of Ilgwang Fault (일광단층 인근 화산암 암반사면의 단열계 기하 분석 및 암반 분류 수정안 제시)

  • Chang, Tae-Woo;Lee, Hyeon-Woo;Chae, Byung-Gon;Seo, Yong-Seok;Cho, Yong-Chan
    • The Journal of Engineering Geology
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    • v.17 no.3
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    • pp.483-494
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    • 2007
  • The properties of fracture system on road-cut slopes along the Busan-Ulsan express way under construction are investigated and analyzed. Fracture spacing distributions show log-normal form with extension fractures and negative exponential form with shear fractures. Straight line segments in log-log plots of cumulative fracture length indicate a power-law scaling with exponents of -1.13 in site 1, -1.01 in site 2 and -1.52 in site 3. It is likely that the stability and strength of rock mass are the lowest in site 1 as judged from the analyses of spacing, density and inter-section of fractures in three sites. In contrast, the highest efficiency of the fracture network for conducting fluid flow is seen in site 3 where the largest cluster occupies 73% through the window map. Based on the field survey data, this study modified weighting values of the RMR system using a multiple regression analysis method. The analysis result suggests a modified weighting values of the RMR parameters as follows; 18 for the intact strength of rock; 61 for RQD; 2 for spacing of discontinuities; 2 for the condition of discontinuities; and 17 for ground water.

Appropriate Root-zone Temperature Control in Perlite Bag Culture of Tomato during Winter Season (저온기 토마토 펄라이트 자루재배시 최적 근권온도 조절 방법)

  • Kim, Sung-Eun;Sim, Sang-Youn;Lee, Sang-Don;Kim, Young-Shik
    • Horticultural Science & Technology
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    • v.28 no.5
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    • pp.783-789
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    • 2010
  • The effective method for heating root-zone during winter season was studied in the aspects of growth, yield and economics for tomato ($Solanum$ $lycopersicum$) in perlite bag culture. There were four root-zone heating treatments: two hours heating from one hour before to one hour after sunrise, four hours from two hours before to two hours after sunrise, 15 hours after sunset, and no heating. The growth characteristics of the upper parts of plants were not significantly different among the treatments, but root volume increased with longer heating of the root zone. The Plant Development Index, using stem diameter and the length between growing tip and the upper flowering truss, showed relation between yield per cluster and growth pattern. The treatment heating for four hours was the most economic in terms of growth and yield of tomato.

Development of Bodice Dress Forms by Body Types for Women in Thirties Applying 3D Body Scan Data (3D 인체 스캔 데이터를 활용한 체형별 인대모형 개발에 관한 연구)

  • Suh, Dong-Ae;Oh, Seol-Yong
    • The Journal of the Korea Contents Association
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    • v.12 no.9
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    • pp.136-145
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    • 2012
  • This research proposes a pattern making method for women's bodice by the characters of body types and develops bodice dress forms on their body shapes applying 3D body scan data. 515 women's body scan data was collected and analyzed factor and cluster analysis. Three body types were characterized in normal, obese, and slim group. In each group, 10 subjects were selected. 20 parts in 3D anthropometric data were measured using Autocad program. The amount of waist dart was calculated and three types of basic bodice pattern were developed using the calculated darts data. The amount and the position of front dart and side dart were different at obese group in comparison of normal and thin group. The three types of basic bodice model were made by the basic bodice pattern, and each model was scanned by 3D scanner to make 3D bodice dress forms. Three types of bodice dress forms were rendered using 3D max program. Bodice dress forms had the dart lines and were useful to draft patterns to fit their body shape.