• Title/Summary/Keyword: K-mean Grouping

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Exploratory Study on the Quality Grade of Korea Black Raspberry Wines by Using Consumer Preference Data (시판 복분자주의 기호도 분석을 통한 탐색적 등급 분류)

  • Lee, Seung-Joo
    • Korean Journal of Food Science and Technology
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    • v.46 no.3
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    • pp.352-357
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    • 2014
  • In this study, 100 consumers (men, 50; women, 50; age group, 20-50 years) rated their overall preferences for 24 Korean raspberry wines by using a 9-point hedonic scale. The analysis of variance was constructed to evaluate the effect of gender, age, and samples on the preference scores of the wine products. Significant differences were observed in overall preferences for the 24 samples; however, no interactions based on preferences by age and gender groups were noted. Cluster analysis was performed to determine sample clustering based on the frequencies from the preference data. Three clusters were obtained; these three clusters were well separated based on the mean overall preference scores for the samples. Discriminant analysis based on the three clusters also confirmed the same grouping of samples with 100% accuracy.

Classification of Shear Strength according to Breccia Content in Fault Core (단층각력 함량에 따른 전단강도의 분류)

  • Yun, Hyun-Seok;Moon, Seong-Woo;Seo, Yong-Seok
    • Economic and Environmental Geology
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    • v.53 no.2
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    • pp.167-181
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    • 2020
  • Analysis of variance (ANOVA) and multiple comparison analysis were performed for shear strengths categorized by breccia content of 5 wt.% (Case-I), 10 wt.%, (Case-II) and 15 wt.% (Case-III) in fault cores. The relationship between breccia contetnt and shear strength was quantitatively classified by calculating the mean and standard deviation of shear strength for each population in each case and then the grouping the breccia contents that had a statistically similar effect on the dispersion of shear strength. As a result, shear strength was clearly classified into group 1 (breccia content of 0-15 wt.%) and group 2 and 3 (breccia coantent of 15-30 wt.% and 30 wt.% or more) in Case-III. Shear strength of the standard line at breccia content of 15 wt.% were determined to be 43.6 kPa, 77.6 kPa, and 118.6 kPa at each normal stress (54 kPa, 108 kPa, and 162 kPa), respectively. In addition, the distribution range of cohesions is 0-43.6 kPa at breccia content of 15 wt.% or less, and 0-70.0 kPa at 15 wt.% or more. Distribution range of friction angles is 0-45.7 ° at breccia content of 15 wt.% or less, and 16.7-57.5 ° at 15 wt.% or more.

Age Differences in Signs and Symptoms of Patients with Temporomandibular Disorders

  • Jo, Jung Hwan;Park, Ji Woon;Kim, Ji Rak;Seo, Hyong Duk;Jang, Ji Hee;Chung, Jin Woo
    • Journal of Oral Medicine and Pain
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    • v.40 no.2
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    • pp.55-62
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    • 2015
  • Purpose: The aims of this study were to evaluate the differences in subjective symptoms, clinical characteristics, distribution according to Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD) subgroup, psychological profile of TMD patients, and to identify the prevalence and trend according to age. Methods: A total of 1,052 patients (261 men and 791 women; mean age, $34.40{\pm}15.73$ years) who visited the Orofacial Pain Clinic of the Department of Oral Medicine, Seoul National University Dental Hospital complaining of TMD symptoms of were evaluated. All patients were questioned for medical history, clinical symptoms and contributing factors. Clinical examination and patient grouping based on RDC/TMD was conducted. Radiographies were taken. The Korean version of RDC/TMD axis II and Symptom Checklist-90-Revision (SCL-90-R) were administered to evaluate pain-related disability level and psychological status of the patients. Results: Prevalence peaked in the 20-year-old age group. There were more women than men in all groups. The highest T-score among SCL-90-R dimensions was somatization in each group, except for teenagers who showed the highest T-score in interpersonal sensitivity. The 30-year-old age group showed the highest distribution of high disability based on the graded chronic pain scale. Age was positively associated with pain intensity (r=0.100), number of positive muscles on palpation (r=0.137) and negatively associated with maximum mouth opening (r=-0.168). Conclusions: Subjective symptoms and clinical characteristics of TMD patients show distinct tendencies according to different age groups. Treatment should be customized and personalized according to age for efficient symptom resolution and patient satisfaction.

Clinical Study in Twin Pregnancies;III. The Second Twin (쌍태임신에 관한 임상통계학적 연구;III. 제 2 쌍 태 아)

  • Kang, H.W.;Kim, D.H.;Park, T.K.;Kwak, H.M.
    • Clinical and Experimental Reproductive Medicine
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    • v.9 no.1_2
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    • pp.29-41
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    • 1982
  • This retrospective clinical study was done based under the delivery records of 146 cases of twin pregnancies in Yonsei University, Severance Hospital and Wonju Christian Hospital from 1977 through 1980 with particular interest in the second twins. Clinical factors, Apgar scores related to neonatal prognosis, and perinatal mortality rate were statistically analyzed and the following results were obtained. The mean - birthweight for A (first) twins was 2,377 grams and for B (second) twins 2,296 grams. In comparison of the percentage of low-birth-weight (less than 2,500 grams) infants, there were more small B twins, but the difference was statistically not significant. Because there were no significant statistical differences in birth weight-grouping between A and B twins, they could be compared with the comprehensive Apgar scores, but this method was also shown to be statistically not significant. In comparison of the percentage of breech deliveries in A and B twins, the percentage was more than three times in B twin (A twin, 7.5 per cent; B twin, 24.0 per cent), and the difference was statistically very significant (p < 0.0005). There were no significant statistical differences between the Apgar scores of A and B twins in reference to the manner of delivery. According to the manner of delivery of B twins, spontaneous vertex delivery and total breech extraction revealed higher infant mortality rate than others. B twins presented by the vertex in 88 cases (61.0 per cent), by the breech in 55 cases (37.0 per cent), and by the shoulder in 3 cases (2.0 per cent). And this therefore disclosed no significant statistical differences in Apgar scores in relation to the presentation. The duration of labor appeared to have no clear correlation with the Apgar scores and the perinatal mortality of A and B twins. The delivery interval between A and B twins was 11.9 minutes on an. averge, varying from 3 to 65 minutes. The length of this interval was not found to have any significant effect on the Apgar scores and the perinatal mortality rate of B twin.

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An Efficient Clustering Algorithm based on Heuristic Evolution (휴리스틱 진화에 기반한 효율적 클러스터링 알고리즘)

  • Ryu, Joung-Woo;Kang, Myung-Ku;Kim, Myung-Won
    • Journal of KIISE:Software and Applications
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    • v.29 no.1_2
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    • pp.80-90
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    • 2002
  • Clustering is a useful technique for grouping data points such that points within a single group/cluster have similar characteristics. Many clustering algorithms have been developed and used in engineering applications including pattern recognition and image processing etc. Recently, it has drawn increasing attention as one of important techniques in data mining. However, clustering algorithms such as K-means and Fuzzy C-means suffer from difficulties. Those are the needs to determine the number of clusters apriori and the clustering results depending on the initial set of clusters which fails to gain desirable results. In this paper, we propose a new clustering algorithm, which solves mentioned problems. In our method we use evolutionary algorithm to solve the local optima problem that clustering converges to an undesirable state starting with an inappropriate set of clusters. We also adopt a new measure that represents how well data are clustered. The measure is determined in terms of both intra-cluster dispersion and inter-cluster separability. Using the measure, in our method the number of clusters is automatically determined as the result of optimization process. And also, we combine heuristic that is problem-specific knowledge with a evolutionary algorithm to speed evolutionary algorithm search. We have experimented our algorithm with several sets of multi-dimensional data and it has been shown that one algorithm outperforms the existing algorithms.

Diversity of I-SSR Variants in Gingko biloba L. Planted in 6 Regions of Korea (국내(國內) 6개(個) 은행(銀杏)나무 식재지(植栽地)에 있어서 I-SSR 변이체(變異體)의 다양성(多樣性))

  • Hong, Yong-Pyo;Cho, Kyung-Jin;Hong, Kyung-Nak;Shin, Eun-Myeong
    • Journal of Korean Society of Forest Science
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    • v.90 no.2
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    • pp.169-175
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    • 2001
  • Genomic DNAs were extracted from the leaves of 182 ginkgo trees (Ginkgo biloba L.) planted in 6 regions and subjected to the analysis of both I-SSR and RAPD markers. A total of 227 amplicon variants were generated by PCR using 15 I-SSR primers and 67 amplicons by PCR with 5 RAPD primers. Levels of genetic diversity within 6 populations were turned out to be similar (Shannon's Index, I-SSR : 0.35~0.40; mean of 0.38, RAPD : 0.31~0.38; mean of 0.35, combined : 0.35~0.40; mean of 0.37). Ranks of the level of genetic diversity estimated from I-SSR, RAPD, and combined data were not coincided each other. Majority of genetic diversity was allocated among individuals within populations (I-SSR : 94.31%, RAPD : 93.62%, combined : 93.57%), which resulted in pretty low level of population differentiation. Genetic differentiation between male and female groups was turned out to be quite low (I-SSR : 0.03, RAPD : 0.091, combined : 0.043), which slightly fluctuated when analysis was restricted to the data obtained from 3 regions where both male and female trees were sampled (I-SSR : 0.038, RAPD : 0.084, combined : 0.047). Genetic relationships among the populations, reconstructed by UPGMA, were not coincided with geographic affinity, which might be resulted from sharing of seed sources in some regions. Whereas independent cluster analyses with I-SSR data and RAPD data, respectively, reclassified by sexes revealed two sexual groups in which all the male and the female populations were clustered together, cluster analysis with combined data did not show clear sexual grouping.

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The effects of family stress and social support resources on marital satisfaction among middle-aged married men and women (중년기 기혼남녀의 가족스트레스, 사회적 지지 자원이 결혼생활만족도에 미치는 영향)

  • Park, Ju-Hee
    • Journal of Family Resource Management and Policy Review
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    • v.19 no.4
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    • pp.71-94
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    • 2015
  • The purpose of this study is to propose measures for social work practice to enhance the happiness of middle-aged married men and women by identifying the effects of family stress and social support resources (formal and informal support resources) on marital satisfaction among mid-life married couples. Subjects were selected through purposive sampling among married men and women aged between 40 and 59 and living in Seoul City and Gyeonggi province. The study results are follows. First, the average score of family stress was 3.06 points (SD=.56), slightly higher than the median value of 3 points. Of all subscales of family stress, the subjects experienced the most stress from family relationships, followed by financial problems, health and loss of families, and work-family compatibility. In regard to social support resources, the mean value of all social support resources categories was greater than the median. Among the subscales, informal support (family support and support from other people) was found to be higher than formal support. The level of marital satisfaction was higher than the median, and the score was 3.21 points (SD=.78). Second, in order to explore differences in marital satisfaction according to family stress and social support, differences in marital satisfaction were analyzed by grouping subjects who scored high, middle, and low levels of marital satisfaction. According to the results, marital satisfaction was statistically significantly higher in the group that experienced less family stress (F=6.25, p<.01). With respect to social support, marital satisfaction was statistically significantly higher in the group that received high social support (F=29.68, p<.001). Third, according to the analysis of factors affecting marital satisfaction in middle-aged married men and women, subjective economic status, family relationship stress, economic stress, and family support showed statistical significance. The higher the subjective economic status and the lower the family relationship stress and economic stress levels, the higher the marital satisfaction among middle-aged married men and women. In addition, the greater the family support, the higher the marital satisfaction. The results of this study underscore the need to improve family relationships in middle-aged married couples and to distribute family life education programs that can strengthen family support resources. For example, family relationship enhancement programs are currently performed, including "Family School for Middle-Aged Baby Boomers" and others as part of the Healthy Family Support Work regarding the promotion of marital satisfaction of middle-aged couples. In addition, continuing effort is warranted to include content on strengthening family support resources, maximizing the effectiveness of programs, and promoting service accessibility.

Study on the Chemical Management - 2. Comparison of Classification and Health Index of Chemicals Regulated by the Ministry of Environment and the Ministry of the Employment and Labor (화학물질 관리 연구-2. 환경부와 고용노동부의 관리 화학물질의 구분, 노출기준 및 독성 지표 등의 특성 비교)

  • Kim, Sunju;Yoon, Chungsik;Ham, Seunghon;Park, Jihoon;Kim, Songha;Kim, Yuna;Lee, Jieun;Lee, Sangah;Park, Donguk;Lee, Kwonseob;Ha, Kwonchul
    • Journal of Korean Society of Occupational and Environmental Hygiene
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    • v.25 no.1
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    • pp.58-71
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    • 2015
  • Objectives: The aims of this study were to investigate the classification system of chemical substances in the Occupational Safety and Health Act(OSHA) and Chemical Substances Control Act(CSCA) and to compare several health indices (i.e., Time Weighted Average (TWA), Lethal Dose ($LD_{50}$), and Lethal Concentration ($LC_{50}$) of chemical substances by categories in each law. Methods: The chemicals regulated by each law were classified by the specific categories provided in the respective law; seven categories for OSHA (chemicals with OELs, chemicals prohibited from manufacturing, etc., chemicals requiring approval, chemicals kept below permissible limits, chemicals requiring workplace monitoring, chemicals requiring special management, and chemicals requiring special heath diagnosis) and five categories from the CSCA(poisonous substances, permitted substances, restricted substances, prohibited substances, and substances requiring preparation for accidents). Information on physicochemical properties, health indices including CMR characteristics, $LD_{50}$ and $LD_{50}$ were searched from the homepages of the Korean Occupational and Safety Agency and the National Institute of Environmental Research, etc. Statistical analysis was conducted for comparison between TWA and health index for each category. Results: The number of chemicals based on CAS numbers was different from the numbers of series of chemicals listed in each law because of repeat listings due to different names (e.g., glycol monoethylether vs. 2-ethoxy ethanol) and grouping of different chemicals under the same serial number(i.e., five different benzidine-related chemicals were categorized under one serial number(06-4-13) as prohibited substances under the CSCA). A total of 722 chemicals and 995 chemicals were listed at the OSHA and its sub-regulations and CSCA and its sub-regulations, respectively. Among these, 36.8% based on OSHA chemicals and 26.7% based on CSCA chemicals were regulated simultaneously through both laws. The correlation coefficients between TWA and $LC_{50}$ and between TWA and $LD_{50}$, were 0.641 and 0.506, respectively. The geometric mean values of TWA calculated by each category in both laws have no tendency according to category. The patterns of cumulative graph for TWA, $LD_{50}$, $LC_{50}$ were similar to the chemicals regulated by OHSA and CCSA, but their median values were lower for CCSA regulated chemicals than OSHA regulated chemicals. The GM of carcinogenic chemicals under the OSHA was significantly lower than non-CMR chemicals($2.21mg/m^3$ vs $5.69mg/m^3$, p=0.006), while there was no significant difference in CSCA chemicals($0.85mg/m^3$ vs $1.04mg/m^3$, p=0.448). $LC_{50}$ showed no significant difference between carcinogens, mutagens, reproductive toxic chemicals and non-CMR chemicals in both laws' regulated chemicals, while there was a difference between carcinogens and non-CMR chemicals in $LD_{50}$ of the CSCA. Conclusions: This study found that there was no specific tendency or significant difference in health indicessuch TWA, $LD_{50}$ and $LC_{50}$ in subcategories of chemicals as classified by the Ministry of Labor and Employment and the Ministry of Environment. Considering the background and the purpose of each law, collaboration for harmonization in chemical categorizing and regulation is necessary.

The effect of education and training with balloons on pulmonary function test in children (교육과 풍선을 이용한 연습이 소아 폐기능 검사에 미치는 영향)

  • Hong, Yong Hee;Ha, Sun Mi;Jeon, You Hoon;Yang, Hyeon Jong;Pyun, Bok Yang
    • Clinical and Experimental Pediatrics
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    • v.51 no.5
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    • pp.506-511
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    • 2008
  • Purpose : The results of pulmonary function test (PFT) in children are variable according to the patient's cooperation and comprehensiveness. This study has intended to figure out the effectiveness of pre-education and training with balloons on PFT in children. Methods : One hundred six children mean aged $9.35{\pm}2.92\;years$ were tested. All participants performed PFT twice in 30 minutes intervals. First PFT were performed after usual instruction and second PFT were performed according to randomly classified grouping; Group 1 : repeat PFT after training with balloons, Group 2 : repeat PFT after training and education, both, Group 3 : repeat PFT after education about objects and necessities of pulmonary function test, Group 4 : repeat PFT without any education and training. Results : There were no difference statistically on the results of percent of predicted $FEV_1$, $FEV_1/FVC$, $FEF_{25-75%}$ and PEFR in Group 1, 2 and 4 patients. In some cases, the average is decreased with repeated PFT. At the case of repeated PFT after education, the average of percent of predicted $FEV_1$, $FEV_1/FVC$, $FEF_{25-75%}$ and PEFR is increased. There was statistically significant difference on the value of $FEV_1$, $FEF_{25-75%}$ and PEFR between first and second PFT in Group 3. Conclusion : Training with balloons before PFT causes fatigueness and lowers concentration. Understanding of PFT makes results better than training. Therefore, enough explanation and education about PFT before examination is most effective for appropriate PFT in children.