• 한국동물학회지
• /
• 제26권2호
• /
• pp.95-106
• /
• 1983

Drosophila melanogaster의 Oregon-R 계통과 lethal free 집단을 대상으로 connected test tube apparatus를 사용하여 보행행동에 관한 rapid와 slow 행동을 방향성도태의 방법으로 15세대 동안에 걸쳐 도태하였다. 한편 10세대째부터 natural selection을 행하여 유전적 효과를 분석하였다. 1. 보행행동의 rapid와 slow 성질은 초기세대에서부터 뚜렷한 도태효과를 나타내어 제 7세대 이후에 각각 selection plateau에 달하였다. 2. 방향성 도태를 10세대 동안 실시한 후 realized heritability를 계산한 결과 rapid 성질은 $9\\sim14%$, slow 성질은 $11\\sim16%$로서 rapid행동보다 slow 행동의 유전율이 다소 높게 나타났다. 3. Rapid 성질을 지배하는 유전자와 slow 성질을 지배하는 유전자의 우열관계를 밝히기 위한 hybridization 실험결과 slow 유전자가 rapid 유전자에 대하여 partial dominance의 효과가 있었다. 4. 10세대 동안에 걸쳐 방향성 도태를 실시한 후 natural selection을 5세대 동안 실시한 결과 rapid 성질은 단 5세대만에 neutral의 상태 (6.5)로 복원되었으나 slow 성질은 모집단의 보행지수와 비교하여 전혀 변화가 없었다. 실험결과로 미루어 rapid와 slow 형질은 polygenic system에 의하여 control 되는 양적 형질임을 알았다. 한편 rapid 유전자는 natural selection에 의한 homeostasis의 효과가 있으나 slow 행동은 소수의 major gene에 의하여 지배되는 것을 알았다.

• 한국병원경영학회지
• /
• 제27권3호
• /
• pp.1-14
• /
• 2022

Purposes: This purpose of this study was to check how much the online word of mouth influences on customer's hospital selection according to Kano's model. Methodology: Kano classified the attributes that affect customer's satisfaction into attractive, one-dimensional, indifferent, must-be, and reverse attributes. Among them, attractive and one-dimensional attributes make up the largest portion in hospital selection. Based on this, the influence of positive or negative online reviews on the selection of hospitals was investigated. Differentiated service was selected as the attractive attributes, and a kind, sufficient explanation was selected as the one-dimensional attributes. Then a questionnaire was conducted how much the positive or negative online reviews influence on hospital selection, respectively. It was conducted from August 7 to September 7, 2021 for medical consumers in their 20s and older who have used medical services for the past 3 years, and the final 142 questionnaires were analyzed. All data was analyzed by chi-square and two-way ANOVA using SPSS ver 25.0. Findings: The results showed that, in one-dimensional attributes, the difference between positive and negative reviews was not statistically significant, but in attractive attributes, positive and negative reviews showed a statistically significant difference. It suggests that positive reviews on attractive attributes had a greater influence on hospital selection. In terms of hospital selection, when the experimental participants were exposed to the positive reviews, the hospital selection ratio did not differ by Kano's attributes, but to the negative reviews it differed. The hospital selection ratio, even after they were exposed to negative reviews, was higher in the attractive attributes than in the one-dimensional attributes. Practical Implication: This study confirmed that hospital selection is influenced differently depending on the Kano's attributes and the direction of the reviews, and suggests that marketers should respond differently to each Kano's attributes when they deal with online reviews of hospitals.

• Animal Bioscience
• /
• 제35권6호
• /
• pp.804-813
• /
• 2022

Objective: A formula is needed that is practical for current livestock breeding methods and that predicts the approximate rate of inbreeding (ΔF) in populations where selection is performed according to four-path programs (sires to breed sons, sires to breed daughters, dams to breed sons, and dams to breed daughters). The formula widely used to predict inbreeding neglects selection, we need to develop a new formula that can be applied with or without selection. Methods: The core of the prediction is to incorporate the long-tern genetic influence of the selected parents in four-selection paths executed as sires to breed sons, sires to breed daughters, dams to breed sons, and dams to breed daughters. The rate of inbreeding was computed as the magnitude that is proportional to the sum of squared long-term genetic contributions of the parents of four-selection paths to the selected offspring. Results: We developed a formula to predict the rate of inbreeding in populations undergoing four-path selection on genomically enhanced breeding values and with discrete generations. The new formula can be applied with or without selection. Neglecting the effects of selection led to underestimation of the rate of inbreeding by 40% to 45%. Conclusion: The formula we developed here would be highly useful as a practical method for predicting the approximate rate of inbreeding (ΔF) in populations where selection is performed according to four-path programs.

• Asian-Australasian Journal of Animal Sciences
• /
• 제18권6호
• /
• pp.772-779
• /
• 2005

The objectives of this study were to examine problems with using F$_1$ data by simulation, association of marker loci and QTL from crosses of inbred parental lines and to enumerate the preliminary characterization of genetic superiority within inbred parental lines. In this study, the association between markers for QTL used as covariates and estimates of variance components due to effects of lines was investigated through computer simulation. The effects of size of population to develop inbred lines and initial frequencies and magnitudes of effects of QTL were also considered. Results show that estimates of variance components due to line effects are influenced by including marker information as covariates in the model for analysis. Estimates of line variance were increased by adding marker information into the analysis, because negative covariances between effects associated with the markers and the remaining effects associated with other loci existed. However, the fit of the model as indicated by the log likelihood improved by adding more markers as covariates into the analysis. Marker assisted selection will be beneficial when markers explain unexplained genetic difference during selection procedure. Markers can be used to identify QTLs affecting traits, and to select for favorable QTL alleles. To efficiently use genetic markers, location of markers at the genome must be identified. The estimates of variance due to effects of with and without marker information used as covariates in the analysis were investigated. The estimates of line variances were always increased when markers were included as covariates for the model because a negative covariance were existed.

• Geomechanics and Engineering
• /
• 제25권1호
• /
• pp.1-16
• /
• 2021

Machine learning models have been widely used for landslide susceptibility assessment (LSA) in recent years. The large number of inputs or conditioning factors for these models, however, can reduce the computation efficiency and increase the difficulty in collecting data. Feature selection is a good tool to address this problem by selecting the most important features among all factors to reduce the size of the input variables. However, two important questions need to be solved: (1) how do feature selection methods affect the performance of machine learning models? and (2) which feature selection method is the most suitable for a given machine learning model? This paper aims to address these two questions by comparing the predictive performance of 13 feature selection-based machine learning (FS-ML) models and 5 ordinary machine learning models on LSA. First, five commonly used machine learning models (i.e., logistic regression, support vector machine, artificial neural network, Gaussian process and random forest) and six typical feature selection methods in the literature are adopted to constitute the proposed models. Then, fifteen conditioning factors are chosen as input variables and 1,017 landslides are used as recorded data. Next, feature selection methods are used to obtain the importance of the conditioning factors to create feature subsets, based on which 13 FS-ML models are constructed. For each of the machine learning models, a best optimized FS-ML model is selected according to the area under curve value. Finally, five optimal FS-ML models are obtained and applied to the LSA of the studied area. The predictive abilities of the FS-ML models on LSA are verified and compared through the receive operating characteristic curve and statistical indicators such as sensitivity, specificity and accuracy. The results showed that different feature selection methods have different effects on the performance of LSA machine learning models. FS-ML models generally outperform the ordinary machine learning models. The best FS-ML model is the recursive feature elimination (RFE) optimized RF, and RFE is an optimal method for feature selection.

• 한국조리학회지
• /
• 제24권3호
• /
• pp.204-214
• /
• 2018

The study set up research models and hypotheses to examine the influence of HMR selection attributes on satisfaction and repurchase intention by distribution channels(convenience store/large market), verify the research hypothesis through empirical analysis, respectively. The purpose of this study is to investigate the convenience sampling method of HMR purchase from convenience store and large market in Seoul and Gyeonggi area. The survey was conducted from January 8, 2018 to January 26, 2018, and 300 questionnaires were distributed and 289 of them were used as an effective data. For the empirical analysis, SPSS 20.0 was used. The results of the analysis are as follows. First, product quality only has a significant effect on satisfaction among HMR selection attributes at convenience store, and product safety and convenience have no significant effect on satisfaction. Second, only the convenience of HMR selection attributes in the large market has a significant effect on satisfaction, and product safety and product quality have no significant effect on satisfaction. Third, HMR satisfaction in convenience stores and large markets has a significant effect on repurchase intention. The purpose of this study is to investigate the relationships among HMR selection attributes, satisfaction, and repurchase intention, which are important in the existing HMR research, by each distribution channel(convenience store/large market). It is meaningful to help them establish an effective sales strategy for each segment.

• Journal of Nutrition and Health
• /
• 제23권7호
• /
• pp.504-512
• /
• 1990

In experiment 1, dietary self-selection of the 3 macronutrients, protein, fat, and carbohydrate were examined in male rats given 3 food cups of 80% carbohydrate, 80% protein, and 70% fat diets simultaneously. All the rats showed normal growth pattern and organ weight, which means they have ability to select just right kinds and amounts of nurients in order to support their growth and development. Mean values of caloric intake, body weight gain, serum lipid values and empty carcass compositions were not significantly differ between the upper and lower quartile groups of fat proportion of empty carcass compared to the lower quartile group(LF). Same feeding design was employed in experiment 2 where the effect of mild electric stress on food selection was studied. The rats in both control and electric stress group revealed a normal growth curve and organ weights. The rats in both control and electric stress group revealed a normal growth curve and organ weights. The stress group showed higher caloric intake and body weight gain than control group, but no significant effects of stress on serum and empty carcass components was found. Even though normal rats seemed to select macronutrients according to their physiolosical needs, there were individual differences in food selection whether they were exposed to stress or not. Therefore life long individual food selection pattern may have a great influence on nutritional status and chronic degenerative diseases of eldery, and on aging process.

• 한국식생활문화학회지
• /
• 제25권5호
• /
• pp.516-524
• /
• 2010

Consumers are highly interested in processed fishery products that are healthy and superior in terms of convenience, nourishment, and taste. However, current domestic research on processed fishery products is marginal. We systematically analyzed consumer consumption patterns and the relationship to pursuit benefits, selection attributes, satisfaction levels, and reasons for purchase. Consumers considered product information the most important selection attribute, whereas convenience scored highest for pursuit benefits. Furthermore, the influences of selection attributes and pursuit benefits on satisfaction level and the reason for purchasing an item were analyzed using demographic properties as control variables. The variables that affected satisfaction level were residential district (region: B= -0.268, p<0.05.), recipe (B=0.098, p<0.05), nutrients (B=0.124, p<0.05), convenience (B=0.283, p<0.001), and economics (B=0.138, p<0.05). The variables affecting the reason for purchasing were nutrients (B=0.173, p<0.001), convenience (B=0.277, p<0.001) and satisfaction level (B=0.163, p<0.001). Pursuit intention had significant effects on purchase intention; however, selection attributes had no significant effect on purchase intention. Therefore, consumer satisfaction had a significant effect on purchase intention. This result showed that if consumers were satisfied, they intended to repurchase. Attempts to increase repurchases by consumer are needed by fulfilling consumer satisfaction. These data can be utilized as a fundamental reference for sales promotions.

• 보건의료산업학회지
• /
• 제6권1호
• /
• pp.105-116
• /
• 2012

Some radiology majors at three-year colleges in Daegu and Gyeongsangbuk-Do Province were selected for the research. The survey was conducted by explaining its objectives and distributing the self-administered questionnaires from March 7 to 30, 2011; then, the final analysis was carried out on 122 copies, drawing the following conclusions : 1) 31.1% of the radiology majors were motivated to enter their department by good employment after graduation, and 37.7% were getting information from their parents or relatives in selecting their major. 2) The majority of the respondents wanted to get a job in a big city after graduation on the basis of good pay. 3) Department selection was significantly affected by transportation, department and school image, and school facilities, and the effects were higher among females. 4) Department satisfaction was significantly affected by professor satisfaction, prospects for the department, and support for employment activities, and the effects were higher among females. 5) School satisfaction was significantly affected by satisfaction with school selection decision, good selection, and school environment, and the effects were higher among females. 6) Females were found to have higher professional consciousness as a radiologist, showing statistically significant differences: "the occupation as a radiologist will continue to be developed" at $3.97{\pm}.837$ for males and at $4.55{\pm}.663$ for females and "the occupation as a radiologist is stable and will be help get a life-long job" at $3.82{\pm}.9.08$ for males and at $4.41{\pm}.787$ for females.

• 한국산학기술학회논문지
• /
• 제16권3호
• /
• pp.1795-1805
• /
• 2015

본 연구는 온라인 저널리즘의 추천기사가 대학생들의 뉴스기사 선택에 미치는 영향을 두 차원에서 분석하였다. 하나는 추천기사이고, 다른 하나는 이들 뉴스기사의 배치순위와 이용지수이다. 분석결과 11개의 추천기사 유형 중 7개 유형은 뉴스기사 선택에 긍정적인 영향을 미치는 것으로 나타난 반면, 4개 유형은 유의미하지 않은 것으로 나타났다. 뉴스기사 선택에 영향을 미치지 않은 것으로 나타난 추천기사 유형의 대부분은 댓글이나 SNS의 트윗과 관련된 것들이다. 또한 뉴스기사 및 검색어 배치순위는 뉴스기사 선택에 영향을 미치는 것으로 나타났으나 이용지수는 영향을 미치지 않은 것으로 나타났다. 한편, 뉴스기사 이용시간과 추천기사 유형 간 그리고 추천기사 유형 간 상관관계는 대부분 유의미한 것으로 나타났다. 분석결과를 종합하면, 뉴스기사 게재위치와 온라인 저널리즘의 추천기사와 같은 형식적 요인은 뉴스기사 헤드라인과 검색어 등의 내용과 더불어 뉴스 이용자들의 뉴스기사 선택에 긍정적인 영향을 미치는 것으로 결론지을 수 있다.