• Title/Summary/Keyword: selection effects

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Longitudinal Analysis of Body Weight and Feed Intake in Selection Lines for Residual Feed Intake in Pigs

  • Cai, W.;Wu, H.;Dekkers, J.C.M.
    • Asian-Australasian Journal of Animal Sciences
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    • v.24 no.1
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    • pp.17-27
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    • 2011
  • A selection experiment for reduced residual feed intake (RFI) in Yorkshire pigs consisted of a line selected for lower RFI (LRFI) and a random control line (CTRL). Longitudinal measurements of daily feed intake (DFI) and body weight (BW) from generation 5 of this experiment were used. The objectives of this study were to evaluate the use of random regression (RR) and nonlinear mixed models to predict DFI and BW for individual pigs, accounting for the substantial missing information that characterizes these data, and to evaluate the effect of selection for RFI on BW and DFI curves. Forty RR models with different-order polynomials of age as fixed and random effects, and with homogeneous or heterogeneous residual variance by month of age, were fitted for both DFI and BW. Based on predicted residual sum of squares (PRESS) and residual diagnostics, the quadratic polynomial RR model was identified to be best, but with heterogeneous residual variance for DFI and homogeneous residual variance for BW. Compared to the simple quadratic and linear regression models for individual pigs, these RR models decreased PRESS by 1% and 2% for DFI and by 42% and 36% for BW on boars and gilts, respectively. Given the same number of random effects as the polynomial RR models, i.e., two for BW and one for DFI, the non-linear Gompertz model predicted better than the polynomial RR models but not as good as higher order polynomial RR models. After five generations of selection for reduced RFI, the LRFI line had a lower population curve for DFI and BW than the CTRL line, especially towards the end of the growth period.

Sperm Selection in Frozen-semen Using Progesterone and BSA (Progesterone과 BSA를 이용한 동결정액내 정자의 선별)

  • 박영식
    • Journal of Embryo Transfer
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    • v.11 no.3
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    • pp.309-316
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    • 1996
  • The aim of this study is to elucidate sperm chemotaxis and to set up the optirnal condition for selection of motile and capacitated sperm from hovine frozen-semen. Thus, the effects of semen-washing after thawing, concentrations of progesterone (P4) and bovine serum albumin (BSA), and sperm-washing frequency on sperm selection were examined. For evaluating their effects, number, viability and acrosome reaction of sperm swim-up seperated from semen, which were incubated for 30 minutes at 36$^{\circ}C$ in the M2 solution containing P4 and BSA, were investigated. For frozen-semen just after thawing, sperm recovery and viability were not significantly different between P4-treated and -untreated semen. However, washing frozen-semen decreased the number of sperm and increased the viability of sperm that were recovered from semen treated with P4. Progesterone affected the recovery rate, the viability and the acrosome-reaction rate of sperm recovered from washed frozen-semen. Especially, number of motile and capacitated sperm were highest in semen treated with 50$\mu$g /ml among 0, 20, 50 and 100$\mu$g /ml of P4 concentrations. BSA affected the recovery rate and the viability of sperm recovered from washed frozen-semen that were treated with 50$\mu$g /ml of P4. Especially, the percentage of viable sperm were highest in semen treated with 4mg /ml among 0, 2, 4, and 6mg /ml of BSA concentrations. Repeatedly sperm-washing did not affect the recovery rate and the viability of sperm recovered from washed frozen-semen that were treated with 50$\mu$g /ml of P4 and 4mg /ml of BSA In conclusion, using progesterone and BSA could efficiently make the selection of motile and capacitated sperm from washed frozen-semen.

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A Study on the Effects of Paramedic Students' Major Selection Motivation and Occupational Values on Employment Preparation Behavior (응급구조(학)과 대학생의 전공선택동기와 직업가치관이 취업준비행동에 미치는 영향에 관한 연구)

  • Park, Daesung;Kim, Yongseok
    • Journal of Digital Convergence
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    • v.18 no.8
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    • pp.263-270
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    • 2020
  • This study was conducted to identify the effects of major selection motivation and occupational values on employment preparation behavior for paramedic students', and to provide basic data for improving employment preparation behavior based on the results. After receiving the consent to participate in the research from November 4 to 8, 2019, a self-written questionnaire was conducted for 3rd and 4 year university paramedic students' located in D Metropolitan City and J Province. Among the collected data, 341 parts, except for the 9 parts with insufficient response, were finally analyzed with SPSS ver. 12.0 (Window). Results, personal motivation of major selection motivation, intrinsic work values of occupational values, and extrinsic work values were influenced in order to employment preparation behavior.Therefore, it is considered that it is necessary to open a vocational value course in individual and group counseling and regular or non-regular curriculum considering the characteristics of gender and grade, major selection motivation, and occupational oalues.

Effects of Food Selection Attribute on Post-purchase Consumer Behavior in Big Discount Stores (대형 할인점에서 식품 선택 속성이 소비자의 구매 후 행동에 미치는 영향)

  • Jung, Gi-Jin
    • Culinary science and hospitality research
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    • v.15 no.3
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    • pp.248-261
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    • 2009
  • The purpose of this study is to examine the effects of selection attribute in big discount stores upon post-purchase consumer behavior and provide reference materials required for big discount stores to develop customer satisfaction strategies. As a result, this study shows the following findings: First, product-related factors had positive effects on post-purchase consumer behavior. Second, service-related factors had positive effects on post-purchase consumer behavior. Third, store-related factors had positive effects on post-purchase consumer behavior. Conclusively, it is advisable that big discount stores provide a variety of personalized services for customers to create and attract their trust, motivating effective recommendation to their acquaintances.

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Mixed-effects LS-SVR for longitudinal dat

  • Cho, Dae-Hyeon
    • Journal of the Korean Data and Information Science Society
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    • v.21 no.2
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    • pp.363-369
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    • 2010
  • In this paper we propose a mixed-effects least squares support vector regression (LS-SVR) for longitudinal data. We add a random-effect term in the optimization function of LS-SVR to take random effects into LS-SVR for analyzing longitudinal data. We also present the model selection method that employs generalized cross validation function for choosing the hyper-parameters which affect the performance of the mixed-effects LS-SVR. A simulated example is provided to indicate the usefulness of mixed-effect method for analyzing longitudinal data.

A Selection Attributes' Importance-Satisfaction Study for the Hotel and Independent Buffet Restaurants (호텔 뷔페레스토랑과 독립 뷔페레스토랑 선택속성의 중요도와 만족도에 관한 연구)

  • Jeong, Ji-Eun;Kim, Chung-Ah
    • Culinary science and hospitality research
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    • v.22 no.4
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    • pp.319-332
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    • 2016
  • The purpose of this study is to suggest management strategies for both upscale hotel buffet restaurants and independent buffet restaurants by conducting an IPA(Important-Performance/satisfaction Analysis) on the selection attributes for buffet type restaurants. Additionally, the effects of the selection attributes' satisfaction on the "intention to recommend" was tested. Surveys were conducted from April 15th through May 4th, 2016 by using both SNS and off-line surveys of consumers with buffet restaurants dining experiences within the previous year, of which a total number of 160 questionnaires were used for the statistical analysis. The result showed a few different selection attributes in each quadrant; additionally, food quality and menu had positive effects on the "intention to recommend" for hotel buffet restaurants, while food quality was the only selection attribute with positive effects for independent buffet restaurants. Based on the results of the study, it can be suggested for the hotel buffet restaurants to constantly develop new and unique menu items to lead the needs of the fast changing consumers of today instead of focusing on the premium characteristics of upscale hotels and their brand names. In addition, offering a variety desserts seems to be something to re-consider for both types of buffet restaurants.

A Study on the Potential Effects of Consumer Preference for Beef and Involvement in the Attributes of Beef Selection on Consumers' Purchase Intentions (쇠고기 선택 속성의 관여도와 선호도가 구매 의도에 미치는 영향에 관한 연구)

  • Kim, Gi-Jin;Byun, Gwang-In;Jung, Woo-Seok
    • Culinary science and hospitality research
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    • v.15 no.4
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    • pp.286-298
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    • 2009
  • The purpose of this study is to determine potential associations among consumer preference for American beef, consumers' involvement in selection of desired beef, and their intentions to purchase beef. In order to meet the above purpose, this study surveyed the visitors who shopped at 2 big discount stores selected in each of 3 metropolitan cities(Seoul, Daejeon and Daegu) from July 11 to 13, 2008. Total 278 sheets of the questionnaire were collected and used for final data analysis. As a result, it was found that the consumers responded most sensitively to the safety of food when buying beef but didn't care much about the amount of fat and beef brand. In terms of imported beef, it was found that Australian beef was considered reliable by consumers, and their preference for Korean beef was positively correlated with that for Australian beef. In addition, in regard to the attributes of beef selection, it was found that low involvement group had higher intentions to purchase American beef than high involvement group. In order to determine the potential effects of consumers' involvement in the attributes of beef selection on their intentions to purchase American beef, this study conducted data analysis in control of consumer preference for American beef. As a result, it was found that consumers' involvement in the attributes of beef selection had significant effects on their intentions to buy American beef. And sex was found to be one of the demographic characteristics associated with involvement in the attributes of beef selection, particularly associated with low involvement. Depending on sex, it was found that women had lower preference for American beef than men.

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The Effects of the Decrease in Inter-organizational Risks through IRCM on the Supply-chain Performance of a Firm (파트너 선택과 계약 체결을 통한 조직간 위험 감소가 공급망 성과에 미치는 영향)

  • Choe, Jong-Min
    • Management & Information Systems Review
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    • v.36 no.2
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    • pp.187-206
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    • 2017
  • This study empirically investigated the direct and indirect effects of inter-organizational relationships control mechanisms (IRCM; prudent partner selection and complex contract) on the decrease of inter-organizational risks (i.e., relational risk and performance risk). The empirical results showed that prudent partner selection has a positive impact on the degrees of inter-organizational cooperation and the levels of inter-organizational information flow. The effects of complex contract on the inter-organizational cooperation and information flow were not significant. In the results of the decrease of inter-organizational risks, it was observed that inter-organizational cooperation has significant positive effects on the decrease of both relational risk and performance risk. It was found that partner selection only influences the decrease of performance risk. The impact of inter-organizational information flow on the decrease of inter-organizational risks was not statistically significant. The indirect effects of IRCM on the decrease of performance risk through inter-organizational cooperation were also empirically demonstrated. The significant impact of inter-organizational cooperation on the decrease of risks implies that high levels of collaborations among employees decrease the risk of opportunistic behavior as well as the possibility of low degrees of performance through cooperative efforts. According to the results of the effects of risks on supply-chain performance, only the impact of performance risk was negatively significant. This result points out that the low levels of performance cause delays in delivery and product launch, deterred production and delayed market response, and these deteriorated managerial activities necessarily decrease the degrees of supply-chain performance.

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Identification and Characterization of Human Genes Targeted by Natural Selection

  • Ryu, Ha-Jung;Kim, Young-Joo;Park, Young-Kyu;Kim, Jae-Jung;Park, Mi-Young;Seo, Eul-Ju;Yoo, Han-Wook;Park, In-Sook;Oh, Berm-Seok;Lee, Jong-Keuk
    • Genomics & Informatics
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    • v.6 no.4
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    • pp.173-180
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    • 2008
  • The human genome has evolved as a consequence of evolutionary forces, such as natural selection. In this study, we investigated natural selection on the human genes by comparing the numbers of nonsynonymous (NS) and synonymous (S) mutations in individual genes. We initially collected all coding SNP data of all human genes from the public dbSNP. Among the human genes, we selected 3 different selection groups of genes: positively selected genes (NS/S${\geq}$3), negatively selected genes (NS/S${\leq}$1/3) and neutral selection genes (0.9