• 제목/요약/키워드: Correlated Random Effects

검색결과 62건 처리시간 0.028초

Genetic Studies on Faecal Egg Counts and Packed Cell Volume Following Natural Haemonchus contortus Infection and Their Relationships with Liveweight in Muzaffarnagari Sheep

  • Yadav, N.K.;Mandal, Ajoy;Sharma, D.K.;Rout, P.K.;Roy, R.
    • Asian-Australasian Journal of Animal Sciences
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    • 제19권11호
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    • pp.1524-1528
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    • 2006
  • A total of 437 animals, comprising lambs aged between 3 and 12 months and adults of either sex of Muzaffarnagari sheep maintained at the Central Institute for Research on Goats, Makhdoom, Farah, Mathura, India were screened to assess the prevalence of Haemonchus contortus infection following natural infection and to identify the various factors affecting faecal egg count (FEC) and packed cell volume (PCV) of ewes and their genetic control. The relationships between FEC, PCV and body weight were also estimated. The prevalence rate for H. contortus infection in the flock under study was 15.7% indicating much lower occurrence of worm infection in lambs up to one year of age. On the other hand, a large proportion i.e., 67.7% of sheep was refractive to natural H. contortus infection. The random effect of sire significantly contributed (p<0.01) variation in log-transformed FEC (LFEC) of ewes. The season of birth had a significant (p<0.01) effect on LFEC of ewes. The lactating ewes had significantly (p<0.01) higher faecal egg counts compared to dry and pregnant ewes. The linear regression effects of the age of ewes on LFEC of animals were significant (p<0.01) in the present study. The heritabilities of LFEC, PCV and body weights of ewes during the course of infection were moderate to high in magnitude and ranged from 0.24 to 0.47. The LFEC of ewes was significantly (p<0.05) and negatively correlated with PCV at both genetic and phenotypic level. The genetic and phenotypic relationships between LFEC and body weights of ewes were -0.26 and -0.06 for this breed. The genetic correlation of PCV and body weight of ewes was positive and high (0.58) and statistically significant (p<0.05) but it was negatively correlated (-0.01) with body weight at the phenotypic level.

Cloud Removal Using Gaussian Process Regression for Optical Image Reconstruction

  • Park, Soyeon;Park, No-Wook
    • 대한원격탐사학회지
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    • 제38권4호
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    • pp.327-341
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    • 2022
  • Cloud removal is often required to construct time-series sets of optical images for environmental monitoring. In regression-based cloud removal, the selection of an appropriate regression model and the impact analysis of the input images significantly affect the prediction performance. This study evaluates the potential of Gaussian process (GP) regression for cloud removal and also analyzes the effects of cloud-free optical images and spectral bands on prediction performance. Unlike other machine learning-based regression models, GP regression provides uncertainty information and automatically optimizes hyperparameters. An experiment using Sentinel-2 multi-spectral images was conducted for cloud removal in the two agricultural regions. The prediction performance of GP regression was compared with that of random forest (RF) regression. Various combinations of input images and multi-spectral bands were considered for quantitative evaluations. The experimental results showed that using multi-temporal images with multi-spectral bands as inputs achieved the best prediction accuracy. Highly correlated adjacent multi-spectral bands and temporally correlated multi-temporal images resulted in an improved prediction accuracy. The prediction performance of GP regression was significantly improved in predicting the near-infrared band compared to that of RF regression. Estimating the distribution function of input data in GP regression could reflect the variations in the considered spectral band with a broader range. In particular, GP regression was superior to RF regression for reproducing structural patterns at both sites in terms of structural similarity. In addition, uncertainty information provided by GP regression showed a reasonable similarity to prediction errors for some sub-areas, indicating that uncertainty estimates may be used to measure the prediction result quality. These findings suggest that GP regression could be beneficial for cloud removal and optical image reconstruction. In addition, the impact analysis results of the input images provide guidelines for selecting optimal images for regression-based cloud removal.

도시가로 보행자 공간의 만족요인 분석에 관한 연구 -대전시 도시 가로 보행자 공간을 중심으로- (A Study on the Analysis of the User's Degree of Satisfaction in Urban Pedestrian Sidewalk -Case Study of Urban Pedestrian Sidewalk in Taejon City-)

  • 김대현
    • 한국조경학회지
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    • 제22권3호
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    • pp.29-40
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    • 1994
  • The purpose of this study was to investigate factors and variables which have significant effects on satisfaction of urban pedestrian sidewalk in taejon city, and to suggest basic information for urban pedestrian sidewalk. These works consist of two phase; The first, tested the user's degree of satisfaction for 37 spots of pedestrian sidewalk slide and then selected 10 spots slide by the stratified random sampling method. The second, analyzed factors and variables of satisfaction of urban pedestrian sidewalk using the semantic differential scale method, and then processed by mean score, correlation, factor analysis, multiful algorithm. The results were summarized as follows; 1) The relationship between the man group and the woman group was highly correlated as well as between the student group.1 and the student group.2 hense these groups statistically showed no difference in satisfaction ratings. 2) Pedestrian sidewalk width, cleanness, pavement materials and construction condition can be significant variables of satisfaction of urban pedestrian sidewalk. 3) Factors covering the satisfaction of urban pedestrian sidewalk have been found to be Environment of pedestrian sidewalk, Vegetation of pedestrian sidewalk and Form of pedestrian sidewalk. By using the control method for the number of factors, C.P. has been obtained as 62.8%.

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Genetic Relationship between Ultrasonic and Carcass Measurements for Meat Qualities in Korean Steers

  • Lee, D.H.;Kim, H.C.
    • Asian-Australasian Journal of Animal Sciences
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    • 제17권1호
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    • pp.7-12
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    • 2004
  • Real time ultrasonic measurements for 13th rib fat thickness (LBF), longissimus muscle area (LEMA) and marbling score (LMS) of live animal at pre-harvest and subsequent carcass measurements for fat thickness (BF), longissimus muscle area (EMA), marbling score (MS) as well as body weight of live animal, carcass weight (CW), dressing percentage (DP), and total merit index (TMI) on 755 Korean beef steers were analyzed to estimate genetic parameters. Data were analyzed using multivariate animal models with an EM-REML algorithm. Models included fixed effects for year-season of birth, location of birth, test station, age of dam, linear and quadratic covariates for age or body weight at slaughter and random animal and residual effects. The heritability estimates for LEMA, LBF and LMS on RTU scans were 0.17, 0.41 and 0.55 in the age-adjusted model (Model 1) and 0.20, 0.52 and 0.55 in the weight-adjusted model (Model 2), respectively. The Heritability estimates for subsequent traits on carcass measures were 0.20, 0.38 and 0.54 in Model 1 and 0.23, 0.46 and 0.55 in Model 2, respectively. Genetic correlation estimate between LEMA and EMA was 0.81 and 0.79 in Model 1 and Model 2, respectively. Genetic correlation estimate between LBF and BF were high as 0.97 in Model 1 and 0.98 in Model 2. Real time ultrasonic marbling score were highly genetically correlated to carcass MS of 0.89 in Model 1 and 0.92 in Model 2. These results indicate that RTU scans would be alterative to carcass measurement for genetic evaluation of meat quality in a designed progeny-testing program in Korean beef cattle.

Genetic Models for Carcass Traits with Different Slaughter Endpoints in Selected Hanwoo Herds I. Linear Covariance Models

  • Choy, Y.H.;Lee, C.W.;Kim, H.C.;Choi, S.B.;Choi, J.G.;Hwang, J.M.
    • Asian-Australasian Journal of Animal Sciences
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    • 제21권9호
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    • pp.1227-1232
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    • 2008
  • Carcass characteristics data of Hanwoo (N = 1,084) were collected from two stations of the National Livestock Institute of Animal Science (NIAS), Korea and records from thirteen individual cow-calf operators were analyzed to estimate variance and covariance components and the effect of different slaughter endpoints. Carcass traits analyzed were cold carcass weight (CWT, kg), REA (rib eye area, cm2), back fat thickness (mm) and marbling score (1-7). Four different models were examined. All models included sex and contemporary group as fixed effects and the animal's direct genetic potential and environment as random effects. The first model fitted a linear covariate of age at slaughter. The second model fitted both linear and quadratic covariates of age at slaughter. The third model fitted a linear covariate of body weight at slaughter. The fourth model fitted both linear covariates of age at slaughter and body weight at slaughter. Variance components were estimated using the REML procedure with Gibb's sampler. Heritability estimate of CWT was in the range of 0.08-0.11 depending on the model applied. Heritability estimates of BF, REA and MS were in the ranges of 0.23-0.28, 0.19-0.26, and 0.44-0.45, respectively. Genetic correlations between CWT and BF, between CWT and REA, and between CWT and MS were in the ranges of -0.33 - -0.14, 0.73-0.84, and -0.01- 0.11, respectively. Genetic correlations between REA and BF, between MS and BF and between REA and MS were in the ranges of -0.82 ~ -0.72, 0.04~0.28 and -0.08 ~ -0.02, respectively. Variance and covariance components estimated varied by model with different slaughter endpoints. Body weight endpoint was more effective for direct selection in favor of yield traits and body weight endpoints affected more of the correlated response to selection for the traits of yield and quality of edible portion of beef.

영과잉 공간자료의 분석 (Zero In ated Poisson Model for Spatial Data)

  • 한준희;김창훈
    • 응용통계연구
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    • 제28권2호
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    • pp.231-239
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    • 2015
  • 가산자료(counts data)를 적합 하는 경우 보통 포아송 모형이 가장 먼저 고려된다. 과산포 문제가 있을 경우도 유사 포아송(quasi Poisson) 모형이나 음이항(Negative binomial) 모형으로 대부분 설명이 가능하다. 하지만, 가산자료 중에는 포아송분포를 가정한 기대 빈도 이상으로 많은 0이 관측되는 자료가 있고 이를 영과잉(Zero inflated) 가산 자료라고 부른다. 영과잉 가산자료를 설명하기 위해 영과잉 포아송(ZIP) 모형이나 영과잉 음이항(ZINB) 모형을 이용할 수 있다. 더 나아가 영과잉 가산자료가 공간상관관계까지 있을 경우 영과잉 문제뿐만 아니라 유의할 수 있는 공간효과까지 고려해야하고 이를 위해 혼합효과모형(mixed effects model)이 고려 될 수 있다. 본 연구에서 사용된 2004년 기준 부산시 남성동별 갑상선암 발생자수 자료를 이용하여, 일반선형 포아송모형, 영과잉 포아송모형, 공간 영과잉 포아송모형을 적합하여 비교해보았다.

전공 선택동기, COVID-19 불안, 직업가치관이 취업준비행동에 미치는 영향: 보건계열 대학생을 중심으로 (The Effects of Major Selection Motivation, COVID-19 Anxiety, and Work Values on Employment Preparation Behavior: Focused on Health College Students)

  • 김은정;박사라;임성범
    • 대한통합의학회지
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    • 제10권4호
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    • pp.49-56
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    • 2022
  • Purpose : The purpose of this study was to examine the effects of the motivation for choosing a major, COVID-19 anxiety, and work values on the employment preparation behavior of health college students and to provide evidence for developing programs for employment preparation behavior in the future. Methods : Employing a random sampling method, a survey was conducted from April 22 to June 3, 2022, using an electronically-disseminated questionnaire with college students majoring in medical technician, health administration, and nursing from D and K colleges located in Daegu. A total of 402 students who fully understood and agreed to the purpose of the study participated. The SPSS statistical program was used to analyze the collected data, which were verified using correlation and regression analyses. Results : The results of the study are: First, employment preparation behavior was positively correlated to major selection motivation, COVID-19 anxiety, and work values. Second, significant relationships were found between employment preparation behavior and motivation behind choosing a major, work values, and COVID-19 anxiety, in that order. The higher the major selection motivation, work values, and COVID-19 anxiety were, the better the employment preparation behavior was. Conclusion : The study's results indicate that it would be meaningful to provide health college students who were highly motivated to select their major and who possess sound work values with well-prepared job training programs. Various activities organized by the school for improving the students' self-satisfaction and self-efficacy, which can strengthen their long-term work values, could also be provided. In addition, due to the continuing COVID-19 pandemic, college students may feel anxious about new infectious diseases that might occur in the future. Therefore, considering the contemporary situation, a helpful educational program will be invaluable to fit the pupils for life's battle after they finish their education.

코로나19 팬데믹의 아세안 빈곤에 대한 잠재적 영향 추정 및 시사점 (Estimation of the Potential Impacts of COVID-19 on Poverty in ASEAN Countries)

  • 방호경;양은정
    • 경제분석
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    • 제27권1호
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    • pp.37-66
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    • 2021
  • 본 논문은 COVID-19가 아세안 빈곤에 미칠 잠재적 영향을 실증적으로 추정한다. 빈곤 감소는 국제개발협력의 가장 보편적인 목적이다. 지속가능발전목표(SDGs)에서도 2030년까지 빈곤종식을 목표로 전 세계적 노력을 촉구한 바 있으나 COVID-19는 이러한 노력에 부정적인 영향을 줄 것으로 예상된다. 이러한 배경에서 빈곤에 대한 COVID-19의 영향을 추정하는 것은 개발협력정책의 방향성 수립 및 효과성 제고에 있어 시사하는 바가 크다. 본 논문은 다양한 추정방법을 통해 COVID-19의 빈곤에 대한 잠재적 영향을 정량적으로 추정한다. 첫 번째는 Summer et al. (2020), Nonvide (2020)가 제안한 가계소득 감소 시나리오를 구성한 후 국제빈곤선 조정을 통한 빈곤추정이다. 두 번째는 회귀분석을 통한 추정으로 국가 간 이질성, 불균형데이터, 내생성을 통제한 상관임의효과 모형을 통해 추정한다. 분석결과 COVID-19는 아세안 각국의 빈곤에 악영향을 줄 것으로 나타났다. 특히 빈곤감소를 위해서는 아세안 각국이 경제성장과 더불어 소득불평등도를 감소시키는 정책적 노력을 함께 추진해야 하며, 이는 COVID-19 이전의 빈곤수준으로 빠르게 회복시킬 뿐만 아니라 더 빠른 빈곤감소에 기여할 것으로 분석되었다.

퇴행성 관절염 환자를 대상으로 새로운 진통제 평가를 위한 임상시험자료의 GEE 분석 (Analysis of Repeated Measured VAS in a Clinical Trial for Evaluating a New NSAID with GEE Method)

  • 임회정;김윤이;정영복;성상철;안진환;노권재;김정만;박병주
    • Journal of Preventive Medicine and Public Health
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    • 제37권4호
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    • pp.381-389
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    • 2004
  • Objective : To compare the efficacy between SKI306X and Diclofenac by using generalized estimating equations (GEE) methodology in the analysis of correlated bivariate binary outcome data in Osteoarthritis (OA) diseases. Methods : A randomized, double-blind, active comparator-controlled, non-inferiority clinical trial was conducted at 5 institutions in Korea with the random assignment of 248 patients aged 35 to 75 years old with OA of the knee and clinical evidence of OA. Patients were enrolled in this study if they had at least moderate pain in the affected knee joint and a score larger than 35mm as assessed by VAS (Visual Analog Scale). The main exposure variable was treatment (SKI 306X vs. Diclofenac) and other covariates were age, sex, BMI, baseline VAS, center, operation history (Yes/No), NSAIDS (Y/N), acupuncture (Y/N), herbal medicine (Y/N), past history of musculoskeletal disease (Y/N), and previous therapy related with OA (Y/N). The main study outcome was the change of VAS pain scores from baseline to the 2nd and 4th weeks after treatment. Pain scores were obtained as baseline, 2nd and 4th weeks after treatment. We applied GEE approach with empirical covariance matrix and independent(or exchangeable) working correlation matrix to evaluate the relation of several risk factors to the change of VAS pain scores with correlated binary bivariate outcomes. Results : While baseline VAS, age, and acupuncture variables had protective effects for reducing the OA pain, its treatment (Joins/Diclofenac) was not statistically significant through GEE methodology (ITT:aOR=1.37, 95% CI=(0.8200, 2.26), PP:aOR=1.47, 95% CI=(0.73, 2.95)). The goodness-of-fit statistic for GEE (6.55, p=0.68) was computed to assess the adequacy of the fitted final model. Conclusions : Both ANCOVA and GEE methods yielded non statistical significance in the evaluation of non-inferiority of the efficacy between SKI306X and Diclofenac. While VAS outcome for each visit was applied in GEE, only VAS outcome for the fourth visit was applied in ANCOVA. So the GEE methodology is more accurate for the analysis of correlated outcomes.

돼지의 번식형질과 산육형질에 대한 유전모수 추정 (Genetic Parameter Estimates for Reproductive and Productive Traits of Pig in a Herd)

  • 조충일;안진국;이준호;이득환
    • Journal of Animal Science and Technology
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    • 제54권1호
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    • pp.9-14
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    • 2012
  • 본 연구는 국내 특정 종돈장에서 보유하고 있는 종돈에 대한 번식형질 및 산육형질들에 대한 유전변이를 추정하고자 연구를 실시하였다. 본 분석에 이용된 자료는 2000년부터 2008년까지 개량을 진행한 국내 모종돈장에 있는 돼지(Landrace, Large white, Duroc) 2,447두에서 조사된 9,886복의 번식자료(실산자수, 이유자 돈수)와 10,181두의 산육검정자료(등심단면적, 90 kg 도달일령, 등 지방두께, 정육률)을 이용하여 분석을 실시하였다. 번식형질 및 산육형질에 적합한 모형을 찾기 위해 분산분석을 실시하였으며, 그 결과 번식형질에서 품종효과, 교배웅돈효과, 산차효과, 분만시 년도-계절효과, 산육형질에서 품종효과, 분만시 년도-계절효과, 성의 효과, 모산차 등이 환경요인으로 작용하는 것으로 나타나 이들을 혼합모형방정식에 적합시켜 유전모수를 추정하였다. 그 결과, 번식 형질의 실산자수에 대한 유전력은 0.07, 모체 유전효과에 대한 유전력은 0.02로 추정되었고 이유자돈수의 유전력은 0.03, 모체 유전효과에서 0.02로 추정되었으며 이들 두 형질 간의 유전상관은 0.14, 모체 유전효과에 대한 상관은 0.06로 추정되었다. 또한 등심 면적의 경우 0.19, 90 kg 도달일령은 0.39, 등지방두께 및 정육률은 각각 0.36 및 0.43으로 번식형질에 비해 높은 유전력을 나타내는 것으로 추정되었다. 또한 등심단면적과 등지방두께 간에는 0.04로 유전적 상관관계가 없으며, 등심단면적과 정육률 간에는 0.35로 중도의 유전적 상관관계를 갖는 것으로 추정되었다. 반면에 등지방 두께와 정육률 간은 -0.42로 중도의 부의 상관관계를 나타냈으며, 등지방두께와 90 kg 도달일령 간에는 유전상관이 없는 것(0.00)으로 추정되었다. 또한 번식형질과 산육형질 간 유전상관은 등지방두께를 제외한 나머지 산육형질에서 번식형질과의 부의 상관을 보여, 번식형질 또는 산육형질을 독자적으로 개량하고자 할 때, 부의 관계가 있는 형질과의 유전적 관계를 고려한 개량목표 설정이 필요할 것으로 사료된다.