• Asian-Australasian Journal of Animal Sciences
• /
• 제15권8호
• /
• pp.1222-1226
• /
• 2002

Estimates of genetic correlation between direct and maternal effects for weaning weight of beef cattle are often negative in field data. The biological existence of this genetic antagonism has been the point at issue. Some researchers perceived such negative estimate to be an artifact from poor modeling. Recent studies on sources affecting the genetic correlation estimates are reviewed in this article. They focus on heterogeneity of the correlation by sex, selection bias caused from selective reporting, selection bias caused from splitting data by sex, sire by year interaction variance, and sire misidentification and inbreeding depression as factors contributing sire by year interaction variance. A biological justification of the genetic antagonism is also discussed. It is proposed to include the direct-maternal genetic covariance in the analytical models.

• 경영과학
• /
• 제31권3호
• /
• pp.27-39
• /
• 2014

We derive a generalized statistic form of Q control chart, which is especially suitable for short run productions and start-up processes, for the detection of process mean shifts. The generalization means that the derived control chart statistic concurrently uses within lot variability and between lot variability to explain the process variability. The latter variability source is noticeably prevalent in lot type production processes including semiconductor wafer fabrications. We first obtain the generalized Q control chart statistic when both the process mean and process variance are unknown, which represents the case of implementing statistical process control charting for short run productions and start-up processes. Also, we provide the corresponding generalized Q control chart statistics for the rest of three cases of previous Q control chart statistics : (1) both the process mean and process variance are known (2) only the process mean is unknown and (3) only the process variance is unknown.

• 경영과학
• /
• 제31권1호
• /
• pp.49-61
• /
• 2014

We investigate the hedging effectiveness of incorporating single-stock futures into the corresponding stocks. Investing in only stocks frequently causes too much risk when market volatility suddenly rises. We found that single-stock futures help reduce the variance and risk levels of the corresponding stocks invested. We use daily prices of Korean stocks and their corresponding futures for the time period from December 2009 to August 2013 to test the hedging effect. We also use system trading technique that uses automatic trading program which also has several simulation functions. Moving average strategy, Stochastic's strategy, Larry William's %R strategy have been considered for hedging strategy of the futures. Hedging effectiveness of each strategy was analyzed by percent reduction in the variance between the hedged and the unhedged variance. The results clearly showed that examined hedging strategies reduce price volatility risk compared to unhedged portfolio.

• 지식경영연구
• /
• 제22권3호
• /
• pp.273-293
• /
• 2021

팬데믹(Pandemic)으로 인해 온라인 시장의 규모가 급속하게 커졌다. 일상에서의 비대면화는그동안 기술수용에 늦은 소비자마저 온라인구매의 편리함을 경험하게 하는 계기가 되었고, 이들은 팬데믹 이후에도 온라인구매의 이점을 선호하게 될 것이다. 하지만 이러한 변화의 시기에 소비자가 취할 수 있는 제품 정보는 편평한 디스플레이상의 시각적 정보만으로 축소되었다. 회사들은 차별적이고 경쟁력 있는 정보를 제공하기 위해 AR/VR, Streaming 기술 등을 도입하고 있지만, 정직한 사용자들이 남긴 리뷰는 회사가 제공하는 잘 가공된 정보만큼 소비자에게 강력하게 인식되고, 회사의 상품개발과 마케팅 및 판매 전략을 위한 인사이트를 얻을 수 있다는 점에서 중요하게 인식될 필요가 있다. 그렇다면 소비자의 입장에서, 구매 의사결정 전에 참고하는 리뷰의 평점이 크게 어긋난다면, 소비자들은 어떻게 리뷰정보를 처리할까? 수렴되지 않은 평점은 늘 신뢰할 수 없고 가치 없는 것일까? 본 연구에서는 소비자의 개인 성향으로 볼 수 있는 조절초점 성향이 어떻게 사고방식을 지배하여 수렴되지 않은 정보를 수용하고 처리하는지 보이고자 하였다. 실험은 화장품을 대상으로 제품 리뷰 평점의 분산(높음 vs 낮음)이 소비자의 조절초점(예방초점 vs. 향상초점)에 따라 제품 태도에 어떤 영향을 미치는지 2x2 연구로 설계하였다. 연구결과, 예방초점의 소비자는 분산이 작을 때 높은 제품 태도를 보이지만, 향상초점의 소비자는 분산이 클 때 높은 제품 태도를 보인다는 것을 발견하였다. 이와 같은 연구로, 본 논문은 동일한 평균값의 평가점수를 가진 제품이라도 후기의 분산 값에 따라 소비자의 조절초점 성향이 영향을 미쳐 제품 태도가 달라진다는 것을 설명할 수 있다. 본 논문은 평점이 수렴되지 않는 정보에 대한 소비자의 정보처리의 메커니즘을 밝힌 이론적 공헌이 있으며, 실무적으로 기업은 리뷰가 축적됨에 따라 개인화되고 최적화된 상품 정보를 제공하는 등 빅데이터를 바탕으로 지식경영을 응용한 고객경험설계가 가능함을 시사한다.

• 보건행정학회지
• /
• 제16권1호
• /
• pp.17-40
• /
• 2006

With the prospect of rapidly growing health insurance expenditures, particularly spending for ambulatory care, the introduction of a case-based payment method is discussed as an alternative to the current fee-for-service based method. A system to measure case mixes of providers is a core component of such payment systems. The objective of this study were to develop a classification system for ambulatory care, Korean Ambulatory Patient Group (KAPG) based on the U.S. APG version 2.0 and to evaluate the classification accuracy of the system. A database of 64,258,386 records was constructed from insurance claims submitted to the Health Insurance Review Agency (HIRA) during three months from August 2002. A total of 41,347,307 records with a single visit was used for the development and 7% random sample of the database was used for the evaluation. Additional groups were defined to include both physician and hospital fees in the classification, age splits were added to classify the entire population as well as the population older than 65, and the definition of medical groups used by the HIRA was adopted. The variance reduction in charges achieved by KAPGs was computed to evaluate the accuracy of classification. A total of 474 KAPGs was defined compare to 290 groups in the U.S. APG. The variance reduction for charges of all visits ranged from 20% to 37% depending on the type of provider, and ranged from 22% to 42% for non-outliers, that were better than those achieved by the system currently used by the .HIRA for its internal review purpose. Although further study is required to improve the classification for complicated care in larger hospitals, the results indicated that KAPGs could be used for better management of costs for ambulatory care.

• Journal of Smart Tourism
• /
• 제3권3호
• /
• pp.5-15
• /
• 2023

Given the increasing information overload among users of online review websites, understanding the manner in which cognitive costs are reduced and efficient information is made reliable has become increasingly important. This study targets a unique consumer review design and explores how reviews from an external peer-to-peer site embedded in an online travel agency (OTA) website influence subsequent evaluation behaviors. The empirical results indicate that (1) embedded external reviews with a high average valence tend to strengthen the influence of the positive evaluation ratio while diminishing the effect of the review volume, and (2) embedded external reviews with a large variance strengthen the positive effect of the review volume while weakening the effect of the positive evaluation ratio on subsequent positive evaluations. The findings provide practical insights for consumers and online platforms.

• 간호행정학회지
• /
• 제12권3호
• /
• pp.482-490
• /
• 2006

Purpose: The purposes were to survey the level of work stress, social support, burnout of insurance review nurses and to measure the main & buffering effect of perceived social support on burnout. Method: The samples were 285 insurance review nurses who were registered in Review Nurses Association of Korea at the period of 25 July and 12 August in 2005. Data were analyzed by using of t-test, Pearson's correlation, stepwise multiple regression, two-way ANOVA. Results: There were significant differences of burnout according to the work experience, position, and work satisfaction of insurance review nurses. Among the variables explaining the level of burnout of review nurses, the most significant variable was work stress, followed by current work satisfaction, social support, position and total variance explained was 40.8%. For the analysis of the buffering effects of perceived social support on work stress and burnout, the interaction between work stress and social support was not significant. Conclusions: It is necessary to construct the social support system and to reduce the work stress in order to reduce the level of the burnout of insurance review nurses.

• Asian-Australasian Journal of Animal Sciences
• /
• 제12권7호
• /
• pp.1142-1151
• /
• 1999

Today, laboratory animal production has decreased world-wide to half the number estimated in 1970 of more than 100 Mio. This is due to the cell-biological assays which replaced animal experimentation as a first allround method to solve biomedical problems. Animal experimentation remains the most significant experimental method for the study of higher organized physiological systems and their multifactorial connections. This requires maximal uniformity of all quantitative traits among the animals used for such studies (mainly mice and rats) and stability of these traits for reproducing such studies at any time world-wide. The success of the developed methods for the standardization of laboratory animals was analyzed and were found only partly be acceptable. Getting a higher degree of uniformity among standardized inbred animals is blocked by "intangible variance". This is caused by influences of ooplasm, shown by experimental twin and clone studies. Manipulation of this component of variance is essential in the future. - Genetic drifts impair the necessary stability of biological traits. There are a few disadvantages associated with the cryopreservation of embryos and other methods are required. - Dogs and cats were replaced by pigs as laboratory animals. A new line of animal production will evolve over the next 25 years with similarities to the present laboratory animal production, because in future pigs were used as donors for xenotransplants for men.

• 여성건강간호학회지
• /
• 제14권1호
• /
• pp.56-65
• /
• 2008

Purpose: The study was to develop an instrument to measure grandmothering stress for Korean day-care grandmothers and to test the validity and reliability of the instrument Method: The items of the instrument were based on a literature review and secondary data, After content validity tests and a pilot test, 20 items were developed. In order to test the reliability and validity of the scale, data were collected from 126 grandmothers. Result: After a factor analysis, five factors and 15 items were selected. These explained 67.2% of the total variance. The first domain was termed 'Health problems', and explained 18.1 % of the total variance, and the second domain of 'Possibility of role substitution' explained 13.8%. The third and the fourth domains were 'Relations with adult children' and 'Grandchildren's characteristics' explaining 12.5% and 12.1 %, respectively. The last domain explained 10.8% of the total variance with the theme 'Restriction of social life' After accomplishing the reliability analysis, Cronbach's alpha coefficient was determined to be .75. Conclusions : This initial step in the development of a Grandmothering Stress Index is valuable to reflect the subject of Grandmothering stress in senior citizens in Korea. Future study should to refine the constitution of the instrument.

• 통상정보연구
• /
• 제9권2호
• /
• pp.65-86
• /
• 2007

This paper reviews the properties and application methods of widely used types of risk measures, identifies the rationale and business-side effects of hedging, derives the theoretical formula of optimal hedging ratio, and analyzes the various functional aspects of VaR(Value-at-risk) as a risk measure and a hedging tool. Especially this paper focuses on the characteristics of VaR compared with other risk measures in terms of their own principal determinants and identifies its stronger aspects in the dimension of hedging strategy tools. As well, this paper provides the detailed processes deriving the optimal hedge ratios based on the distributional parameters and risk factors. In addition, this paper presents the detailed and substantial processes of estimating the minimum variance hedge ratio and minimum-VaR hedge ratio using the actual data and shows that the minimum variance hedge ratio proves helpful for many cases although it is not appropriate for the non-linear portfolio including the option contracts. We demonstrate the trade-off relationship between the minimum variance hedge strategy and the minimum-VaR hedge strategy in their hedging costs and performances through calculation of the respective VaRs and variances of unhedged and hedged portfolios and the optimal hedge ratio and hedging effectiveness values for the given long position in US Dollar with the short position in Euro.