• Title/Summary/Keyword: 다변량정규분포

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Methods for Genetic Parameter Estimations of Carcass Weight, Longissimus Muscle Area and Marbling Score in Korean Cattle (한우의 도체중, 배장근단면적 및 근내지방도의 유전모수 추정방법)

  • Lee, D.H.
    • Journal of Animal Science and Technology
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    • v.46 no.4
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    • pp.509-516
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    • 2004
  • This study is to investigate the amount of biased estimates for heritability and genetic correlation according to data structure on marbling scores in Korean cattle. Breeding population with 5 generations were simulated by way of selection for carcass weight, Longissimus muscle area and latent values of marbling scores and random mating. Latent variables of marbling scores were categorized into five by the thresholds of 0, I, 2, and 3 SD(DSI) or seven by the thresholds of -2, -1, 0,1I, 2, and 3 SD(DS2). Variance components and genetic pararneters(Heritabilities and Genetic correlations) were estimated by restricted maximum likelihood on multivariate linear mixed animal models and by Gibbs sampling algorithms on multivariate threshold mixed animal models in DS1 and DS2. Simulation was performed for 10 replicates and averages and empirical standard deviation were calculated. Using REML, heritabilitis of marbling score were under-estimated as 0.315 and 0.462 on DS1 and DS2, respectively, with comparison of the pararneter(0.500). Otherwise, using Gibbs sampling in the multivariate threshold animal models, these estimates did not significantly differ to the parameter. Residual correlations of marbling score to other traits were reduced with comparing the parameters when using REML algorithm with assuming linear and normal distribution. This would be due to loss of information and therefore, reduced variation on marbling score. As concluding, genetic variation of marbling would be well defined if liability concepts were adopted on marbling score and implemented threshold mixed model on genetic parameter estimation in Korean cattle.

Influence of Parental Socioeconomic Status on Stress, Depression and Suicidal Ideation among Korean Adolescents (부모의 사회 경제적 지위가 청소년의 스트레스, 우울, 자살생각에 미치는 영향)

  • Park, Dahye;Jang, Soong-Nang
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.14 no.6
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    • pp.2667-2676
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    • 2013
  • This study was to examine the relationship between suicidal ideation, depression, stress and their parent's socioeconomic status. Nation-wide representative data from the Korean National Health and Nutrition Examination Survey 2009 were used in this study. 904 adolescents with parent were analysed. Parent's socioeconomic status, especially mother's low educational level and the beneficiaries for national basic livelihood security were significant risk factor for adolescents' suicidal ideation. These associations remained significant in multiple logistic regression controlling for all covariates. The findings in the current study support the global literature on the importance of socioeconomic status in promoting adolescent's mental health. Future prevention intervention efforts to improve adolescent's suicide risk will need to take into consideration parent's and household's socioeconomic conditions. Future study is needed to explore the possible proximal risk factors and mediators between parent's socioeconomic status and mental health among adolescents.

Community Structure and Ecological Characteristics of Berchemia berchemiaefolia Stands at Mt. Naeyon (내연산 망개나무 임분의 군집구조와 생태적 특성)

  • Yong Sik, Hong;I-Seul, Yun;Dong Pil, Jin;Chan Beom, Kim;Hak Koo, Kim;Jin Woo, Lee;Shin Koo, Kang
    • Journal of Korean Society of Forest Science
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    • v.111 no.4
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    • pp.538-547
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    • 2022
  • In this study, the population and community structure of Berchemia berchemiaefolia stands located at Mt. Naeyon (Gyeongbuk, Korea) were quantified, and multivariate analysis was done to determine the correlations between vegetation group types and environmental factors and to have reference data for the conservation and restoration of this species. In total, there were 164 B. berchemiaefolia trees in Mt. Naeyon. The average DBH of the trees was 24.5 cm, forming a normal distribution. It rarely appeared in an understory vegetation height of 3 m. About37.1% of the trees were branched. B. berchemiaefolia stands were classified into two groups: B. berchemiaefolia-Quercus serrata community and B. berchemiaefolia-Carpinus laxiflora community. Canopy gap, organic matter, exchangeable Ca, and cation exchange capacity were the major site characteristics affecting the distribution pattern of the stands. Currently, B. berchemiaefolia trees dominate in Mt. Naeyon, but depending on different habitat positions, the species was in a natural successional stage to C. laxiflora or C. cordata, which is a shade-tolerant species.

A STUDY ON THE RACIAL CLASSIFICATION OF ASIAN CHUM, ONCORHYNCHUS KETA(WALBAUM) BASED ON SCALE CHARACTERISTICS (인상(鱗相)에 의한 아시아계 백연어, Oncorhynchus keta(Walbaum)의 계통판정에 관한 연구)

  • KANG Yong Joo
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.7 no.2
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    • pp.91-97
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    • 1974
  • Two scale characters, the width ana circuli counts of the first-year band, were used in a discriminant function analysis to see how effectively the two scale characters would separate geographical chum stocks from the western North Pacific. A total of 476 scale samples were taken from spawning adults which ascended to rivers of Hokkaido, Japan, in 1956, and Kamchatka, the U.S.S.R., in 1957. The scale characters were examined for conformity to the statistical requirements of a discriminant function. As a result of the examinations the two characters were verified to be able to be used in a discriminant function analysis that would classify chum taken on the high seas to most Probable origin. A discriminant function computed using the two characters correctly classified 78.5 percent of the Hokkaido and Kamchatka chum fish. Of the two characters the number of the circuli could alone classify fish to its origin with nearly the same probability of correct classification as the discriminant function based on the two characters can.

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A Study of 3D Ore-Modeling by Integrated Analysis of Borehole and Geophysical Data (시추자료와 물리탐사자료의 복합해석을 통한 3차원 광체 모델링 연구)

  • Noh, Myounggun;Oh, Seokhoon;Ahn, Taegyu
    • Geophysics and Geophysical Exploration
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    • v.16 no.4
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    • pp.257-267
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    • 2013
  • 3-D ore modeling was performed to understand the configuration of ore bodies by integrated analysis of borehole and geophysical data in iron-mine area. Five representative indices of rocks were designated, which were obtained from geological survey and borehole. The five indices of rocks were geostatistically simulated by Sequential Indicator Simulation method to delineate boundary of the ore bodies. And Ordinary Kriging and Sequential Gaussian Simulation was applied to make secondary information using resistivity data from magnetotellurics and DC resistivity survey, and this information was used for simple kriging with local varying means, one of integrated kriging techniques. From the correlation analysis between each properties, it was found that high grade of ore is characterized by increased density, whereas the electrical resistivity decreases. With the integrated results of geophysical and borehole data, it was also found that the real configuration of ore body was similar to the modeled result and information about ore grade in 3-D space was obtained.

A Review of Multivariate Analysis Studies Applied for Plant Morphology in Korea (국내 식물 형태 연구에 사용된 다변량분석 논문에 대한 재고)

  • Chang, Kae Sun;Oh, Hana;Kim, Hui;Lee, Heung Soo;Chang, Chin-Sung
    • Journal of Korean Society of Forest Science
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    • v.98 no.3
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    • pp.215-224
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    • 2009
  • A review was given of the role of traditional morphometrics in plant morphological studies using 54 published studies in three major journals and others in Korea, such as Journal of Korean Forestry Society, Korean Journal of Plant Taxonomy, Korean Journal of Breeding, Korean Journal of Apiculture, Journal of Life Science, and Korean Journal of Plant Resources from 1997 to 2008. The two most commonly used techniques of data analysis, cluster analysis (CA) and principal components analysis (PCA) with other statistical tests were discussed. The common problem of PCA is the underlying assumptions of methods, like random sampling and multivariate normal distribution of data. The procedure was intended mainly for continuous data and was not efficient for data which were not well summarized by variances or covariances. Likewise CA was most appropriate for categorical rather than continuous data. Also, the CA produced clusters whether or not natural groupings existed, and the results depended on both the similarity measure chosen and the algorithm used for clustering. An additional problems of the PCA and the CA arised with both qualitative and quantitative data with a limited number of variables and/or too few numbers of samples. Some of these problems may be avoided if a certain number of variables (more than 20 at least) and sufficient samples (40-50 at least) are considered for morphometric analyses, but we do not think that the methods are all mighty tools for data analysts. Instead, we do believe that reasonable applications combined with focus on objectives and limitations of each procedure would be a step forward.

Impact of Pulmonary Vascular Compliance on the Duration of Pleural Effusion Duration after Extracardiac Fontan Procedure (수술 전 폐혈관 유순도가 심장 외 도판을 이용한 Fontan 수술 후 늑막 삼출 기간에 미치는 영향)

  • Yun Tae-Jin;Im Yu-Mi;Song Kwang-Jae;Jung Sung-Ho;Park Jeong-Jun;Seo Dong-Man;Lee Moo-Song
    • Journal of Chest Surgery
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    • v.39 no.8 s.265
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    • pp.579-587
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    • 2006
  • Background: Preoperative risk analysis for Fontan candidates is still less than optimal in that patients with apparently low risks may have poor surgical outcome; prolonged pleural drainage, protein losing enteropathy, pulmonary thromboembolism and death. We hypothesized that low pulmonary vascular compliance (PVC) is a risk factor for prolonged pleural effusion drainage after the Fontan operation. Material and Method: A retrospective review of 96 consecutive patients who underwent the Extracardiac Fontan procedures (median age: 3.9 years) was performed. Fontan risk score (FRS) was calculated from 12 categorized preoperative anatomic and physiologic variables. PVC $(mm^2/m^2{\cdot}mmHg)$ was defined as pulmonary artery index $(mm^2/m^2)$ divided by total pulmonary resistance $(W.U{\cdot}/m^2)$ and pulmonary blood flow $(L/min/m^2)$ based on the electrical circuit analogue of the pulmonary circulation. Chest tube indwelling time was log-transformed (log indwelling time, LIT) to fit normal distribution, and the relationship between preoperative predictors and LIT was analyzed by multiple linear regression. Result: Preoperative PVC, chest tube indwelling time and LIT ranged from 6 to 94.8 $mm^2/mmHg/m^2$ (median: 24.8), 3 to 268 days (median: 20 days), and 1.1 to 5.6 (mean: 2.9, standard deviation: 0.8), respectively. FRS, PVC, cardiopulmonary bypass time (CPB) and central venous pressure at postoperative 12 hours were correlated with LIT by univariable analyses. By multiple linear regression, PVC (p=0.0018) and CPB (p=0.0024) independently predicted LIT, explaining 21.7% of the variation. The regression equation was LIT=2.74-0.0158 PVC+0.00658 CPB. Conclusion: Low pulmonary vascular compliance is an important risk factor for prolonged pleural effusion drainage after the extracardiac Fontan procedure.