• 제목/요약/키워드: variance components

검색결과 529건 처리시간 0.023초

Survival in Fry and Juvenile Stages of Masu salmon Oncorhynchus masou : Estimates of Heritabilities and Correlations

  • Choe, Mi-Kyung
    • 한국양식학회지
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    • 제12권3호
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    • pp.185-191
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    • 1999
  • A genetic analysis for survival in fry and juvenile stages of masu salmon was described. Data from two year-classes of masu salmon were analyzed to estimate the heritability for survival during the fresh water-rearing period. The overall survival for each year-class during 8 months of freshwater rearing were 17.8 and 11.6%, respectively. Whirling disease virus (WDV) was the main cause of death in all year-classes. Survival data obtained for offspring of 42 sires and 60 dams of masu salmon (two year classes of data) was analyzed. Average survival rates in the observation period ranged 2-87% for 1994; 0-98% for 1995, repectively. In both year-classes, heritabilities for survival derived from the sire components of variance were low(0.13-0.18), except one. Heritabilities derived from the dam components of variance ranged 0.14-0.61, including non-additive genetic and /or common enviromental effects. Correlations between survival in two long-term periods were all positive and medium to high in magnitude(0.345-0.918). Correlations between survival in non-succeeding periods were, in general, low and insignificant. Correlation between long-term survival and growth rate was found in masu salmon. The corresponding correlation in masu salmon was not significantly different from zero. Correlations between sire survival and body weight, length and condition factor of slaughter were not significant, but varied.

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Relationship between Meteorological Elements and Yield of Perilla in Yeosu Area

  • Kwon, Byung-Sun;Park, Hee-Jin
    • Plant Resources
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    • 제6권3호
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    • pp.178-182
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    • 2003
  • This study was conducted to investigate the relationship between yearly variations of climatic elements and yearly variations of productivity in perilla. In addition, correlation coefficients among yield and yield components were estimated. The data of yield and yield components were investigated for 10 years from 1991 to 2000. The meteorological data gathered at the Yeosu Weather Station for the same period were used to find out the relationships between climatic elements and productivity. Yearly variation of the amount of precipitation in September was large with coefficients of variation(c. v.) of 11.1%, but the coefficient of variance(c. v.) in July and August were relative small with 1.8, 2.1%, respectively. Number of cluster per hill and weight of 1,000 grains were greatly with c. v. of 76.1, 79.3%, respectively, but the coefficients of variance(c. v.) of plant height and seed yield were more less with 9.58, 10.60%, respectively. Correlation coefficients between precipitation of September and seed yield were positively significant correlation at the level of 5.1%, respectively, but the duration of sunshine in September and seed yield were negatively significant at the level of 5.1%, respectively. Correlation coefficients of these, the plant height, number of branches per plant, cluster length, number of cluster per hill, weight of 1,000 grains and seed yield were positively significant at the level of 5.1% respectively.

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Evaluation of clinical usefulness of reference interval of some selected hematological parameters in canine blood

  • Pak, Son-Il;Han, Ho-Jae
    • 대한수의학회지
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    • 제44권4호
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    • pp.649-653
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    • 2004
  • To estimate the source of variance components for some hematological parameters and assess the utility of the conventional population-based reference interval, this study computed index of individuality for blood samples, which were from 13 dogs drawn once weekly for 4 consecutive weeks. Results were subjected to nested analysis of variance. For all parameters measured between-dog variations were greater than within-dog variation. Except for the parameters RBC and MCHC the index of individuality was <1.4. The low reliability coefficient and high index of individuality of ${\leq}0.8$ were found for the majority of hematological parameters. In practical term, the present study indicated that use of hemogram profiles alone in the evaluating clinical state of a single patient should be avoided because of their physiological or natural random variations, and that comparing a single measurement on the blood analytes from an individual dog to the conventional population-based reference range may be too insensitive to detect any significant changes in the blood components of that particular dog. A single measurement may not characterize an individual's average concentration of the parameters even shortterm period.

The effect of missing levels of nesting in multilevel analysis

  • Park, Seho;Chung, Yujin
    • Genomics & Informatics
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    • 제20권3호
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    • pp.34.1-34.11
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    • 2022
  • Multilevel analysis is an appropriate and powerful tool for analyzing hierarchical structure data widely applied from public health to genomic data. In practice, however, we may lose the information on multiple nesting levels in the multilevel analysis since data may fail to capture all levels of hierarchy, or the top or intermediate levels of hierarchy are ignored in the analysis. In this study, we consider a multilevel linear mixed effect model (LMM) with single imputation that can involve all data hierarchy levels in the presence of missing top or intermediate-level clusters. We evaluate and compare the performance of a multilevel LMM with single imputation with other models ignoring the data hierarchy or missing intermediate-level clusters. To this end, we applied a multilevel LMM with single imputation and other models to hierarchically structured cohort data with some intermediate levels missing and to simulated data with various cluster sizes and missing rates of intermediate-level clusters. A thorough simulation study demonstrated that an LMM with single imputation estimates fixed coefficients and variance components of a multilevel model more accurately than other models ignoring data hierarchy or missing clusters in terms of mean squared error and coverage probability. In particular, when models ignoring data hierarchy or missing clusters were applied, the variance components of random effects were overestimated. We observed similar results from the analysis of hierarchically structured cohort data.

A Study of Edge Detection for Auto Focus of Infrared Camera

  • Park, Hee-Duk
    • 한국컴퓨터정보학회논문지
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    • 제23권1호
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    • pp.25-32
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    • 2018
  • In this paper, we propose an edge detection algorithm for auto focus of infrared camera. We designed and implemented the edge detection of infrared image by using a spatial filter on FPGA. The infrared camera should be designed to minimize the image processing time and usage of hardware resource because these days surveillance systems should have the fast response and be low size, weight and power. we applied the $3{\times}3$ mask filter which has an advantage of minimizing the usage of memory and the propagation delay to process filtering. When we applied Laplacian filter to extract contour data from an image, not only edge components but also noise components of the image were extracted by the filter. These noise components make it difficult to determine the focus state. Also a bad pixel of infrared detector causes a problem in detecting the edge components. So we propose an adaptive edge detection filter that is a method to extract only edge components except noise components of an image by analyzing a variance of pixel data in $3{\times}3$ memory area. And we can detect the bad pixel and replace it with neighboring normal pixel value when we store a pixel in $3{\times}3$ memory area for filtering calculation. The experimental result proves that the proposed method is effective to implement the edge detection for auto focus in infrared camera.

단기선 GPS측위 모델을 이용한 관측오차 분석 (Analysis of Measurement Errors Using Short-Baseline GPS Positioning Model)

  • 홍창기;한수희
    • 한국측량학회지
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    • 제35권6호
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    • pp.573-580
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    • 2017
  • GPS 관측값을 이용하여 측위를 하는 경우 조정계산이 수반되면 이때 관측오차에 대한 정확한 모델링이 필수적이다. 본 연구에서는 GPS 관측타입별 관측오차를 분석하기 위해 MINQUE(Minimum Norm Quadratic Unbiased Estimators) 방법을 사용하였으며 단기선 GPS측위 모델을 기반으로 하였다. C1, P2, L1, L2 관측타입에 대해 각각 단위분산을 계산하였으며 그 결과 관측오차는 각각 22.3cm, 27.6cm, 2.5cm, 2.2cm로 나타났다. 단위분산 계산에는 대용량의 컴퓨터 메모리와 복잡한 계산이 필요하다. 이러한 단점을 극복하기 위해 epoch별로 단위분산을 추정하였으며 결과를 분석함으로써 epoch별 계산방법의 유효성을 검증하였다. 분석 결과, 계산된 결과값에 차이가 있긴 했으나 그 차이가 비교적 작기 때문에 대부분의 GPS 응용분야에서의 활용에는 문제가 없을 것으로 판단된다.

고등학교 전정의 공간 Image와 시각적 선호도 조사에 관한 연구 (A Study on the Spatial Image and Visual Preference for Front Gardens of High School)

  • 진희성;서주환
    • 한국조경학회지
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    • 제13권2호
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    • pp.37-70
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    • 1985
  • The purpose of this study is to present objective basic data for environmental design by the quantitative analysis of visual quality emboded in physical environment. For this, as for the front garden of high schools, the spatial image was measured by the S.D. Scale Method, Factor Analysis was proceeded by the principal component analysis and the visual preference was investigated by the Paired Comparision Method. The scale values of plain and unpleasant road surface and external appearance of buildings, which are related to emotions of simpleness fell from straightness and stability, were found to be high. But, except for the road surface of Kyunggi High School, scale values of variables explaining the variation of the quality of materials, level of floor and rythm were generally low. For all green spaces, scale values of variables explaining the degree of pleasantness was found to be generally high. And, those explaining tidiness and characteristics of green spaces were not in the same tendency. But, the green spaces of Youngdong High school can be considered to the space with plenty of visual absorption uniqueness were high. As for the correlation between variables, variables for green spaces(12 and 26) and those for overall view of front garden( 1 and 4) revealed high positive correlation. Also, "order - disorder" and "convenient- incovenient" included in road surface variable can be regarded to have the same meaning since the correlation coefficient between them is very high, 0.7045. Image variables including road surface, external appearance of buildings, green spaces and overall view of front garden showed 91.21~61.08% of total variance. Thus, the remains can be considered to be the error valiance or specific variance. In Fctor I, II and III, main components explaining the road surface image of front gardens are order, hardness, texture, color, gradient and rythm. As for the external appearance of b wilding, variables of color, hardness, stability, peculiality and shape revealed high values of factor load. For all variables, communality was drastically high and ellen values and common variance were found to be very high in Factor I. As for the front gardens, variables explaining volume and peculiarity were found to be the main components of Factor I. In Factor II and III, variables of factor load were tidiness, pleasantness.

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Genetic parameters and litter trait trends of Danish pigs in South Vietnam

  • Tinh, Nguyen Huu;Hao, Tran Van;Bui, Anh Phu Nam
    • Animal Bioscience
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    • 제34권12호
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    • pp.1903-1911
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    • 2021
  • Objective: The objective of this study was to estimate the genetic parameters and various litter trait trends of Danish pigs in South Vietnam, including the number born alive (NBA), number weaned (NW), and litter weight at the 21st day (LW21). Methods: Records of 936 Yorkshire sows with 3361 litters and 973 Landrace sows with 3161 litters were used to estimate the variance components, genetic parameters, and trends of NBA, NW, and LW21. The restricted maximum likelihood method was applied using VCE6 software to obtain the variance components and genetic parameters. Thereafter, the best linear unbiased prediction procedure with an animal model was applied using PEST software to estimate the breeding values of the studied traits. Results: The heritability estimates were low, ranging from 0.12 to 0.21 for NBA, 0.03 to 0.04 for NW, and from 0.11 to 0.13 for LW21. The genetic correlation between the NBA and NW was relatively strong in both breeds, at 0.77 and 0.60 for Yorkshire and Landrace, respectively. Similarly, the genetic correlation between the NW and LW21 was considerably stronger in Landrace pigs (0.71) than in Yorkshire pigs (0.48). The estimates of annual genetic progress were 0.0431, 0.0233, and 0.0461 for NBA, NW, and LW21 in Landrace pigs and 0434, 0.0202, and 0.0667 for NBA, NW, and LW21 in Yorkshire pigs, respectively. Conclusion: The positive genetic trends estimated for the additive genetic values of the selected traits indicated that the current breeding system has achieved favorable results.

웨이브릿에 기반한 영상의 잡음추정 (Wavelet-Based Noise Estimation in Image)

  • 안태경;우동헌;김재호
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2001년도 제14회 신호처리 합동 학술대회 논문집
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    • pp.747-750
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    • 2001
  • The paper presents an algorithm for estimating the variance of additive zero mean Gaussian noise in an image. The algorithm uses the wavelet transform which is a good tool for energy compaction. The algorithm consists of three steps. At first, high frequency components, wavelet coefficients in HH band, are generated from a noisy image by the wavelet transform. In a second step, high frequency components which are out of the noise range ate eliminated. Finally, if the image has many components eliminated in the previous step, then its noise estimated value is reduced. Experimental results show that the wavelet filter has better performance than the other high pass filters such as a Laplacian filter, residual from a median filter, residual from a mean filter, and a difference operator. In various images, the algorithm reduces 50% of estimated error on an average.

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전기자동차의 유럽 OFFSET 충돌 특성 기초 연구 (A Basic Study of the European Offset Characteristics of Electric Vehicle)

  • 조용범;신효철
    • 한국자동차공학회논문집
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    • 제10권3호
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    • pp.111-122
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    • 2002
  • European offset impact analysis of an electric vehicle was done using the robust design method. Section properties of some of the vehicle structure components which influence the european offset impact characteristics were chosen as the main factors fur the design. Eight factors were considered for the analysis: one with two level and seven with three level combinations comprising the L$\_$18/(2$^1$$\times$3$\^$7/) orthogonal array. It is shown that the sensitivities of the factors and the best combination of the factors can be obtained. One of the noteworthy results is that the design with the lower stiffness of the front components of engine room than the rear components can absorb more crash energy. Also it is shown that there exist interactions between some of factors considered.