• 한국경영정보학회:학술대회논문집
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• 한국경영정보학회 2007년도 International Conference
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• pp.395-400
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• 2007

Previous studies present the mixed results on online reputation mechanism. In this study, we have found that an approach based on Bayesian statistics can explain most results of previous studies which are conflicting with each others. With this model, we explain why negative ratings have more significant marginal impacts on sellers' reputation than positive ones do. Furthermore, we even show why the feedbacks with a few negative ratings may increase the value of the item and final prices by confirming buyers' prior beliefs on the sellers' reputation much more than those without negative ratings. Also, we explain why there are not many negative ratings. Even though some studies suggest this because of generosity of users, our model shows that the reason is that the existence of FS itself prevents bad sellers from participating to the market as a signal itself. Even further, we show how this extreme tendency of positive ratings gets even stronger as markets evolve. Finally, to validate our analytical results, we examine the previous studies and see what factors effect the outcomes of their analyses.

• 한국수학교육학회지시리즈A:수학교육
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• 제50권4호
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• pp.507-520
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• 2011

Teaching and learning in schools can be influenced by the ways in which curriculum is understood in terms of its characteristics and range. Viewing curriculum as encompassing all activities pertaining to teaching and learning allows us to examine various aspects of education through curriculum studies. In this respect, this study explores the trends in research on K-12 mathematics curriculum by examining prior studies' research topics categorized into five themes in curriculum studies. In addition, implications for future research are discussed based on the findings of this study.

• 아동학회지
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• 제8권2호
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• pp.1-15
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• 1987

Prior studies on child development have focused mainly on environmental variables including mother variations. However, several studies proved that child variables, especially inherited temperament, influence or change the environment. The current study investigates the temperament of 5 - to 8 - month - old infants. One hundred and forty-three mothers of the infants responded to the RITQ that was devised by Carey and McDevitt (1978). The RITQ examined 9 temperamental categories. Based on the score, the subjects were divided into five subgroups-Difficult, Slow-to-Warm-Up, Intermediate High, Intermediate-Low, and Easy. The important findings are as following : (1) There were significant sex differences. Females appeared to have significantly more representation in the slow-to-warm-up, intermediate-high, and intermediate-low groups. There were more males in the easy group. In the comparison of the two sexes as to the mean score in the nine categories males were found to be more approaching, less intensive, positive mood, and highly distractible. (2) Infants' temperament was not related to the mothers' education level and their work status. (3) The mothers' global ratings were consistent with subgroup temperament characteristics.

• 대한예방의학회:학술대회논문집
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• 대한예방의학회 1994년도 교수 연수회(역학)
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• pp.188-195
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• 1994

To an increasing extent, case-control studies are being undertaken to determine if use of early detection procedures is associated with reduced mortality from cancer. The authors recommend that in such studies the analysis focus on screening activity in cases that occurs during an interval prior to diagnosis in which the cancer is believed to be detectable and still curable and to a corresponding time period in controls. This approach places a heavy burden on the investigator to estimate accurately the period during which the tumor ought to be detectable using the test in question and to sort out reliably tests done in response to signs or symptoms of the cancer from screening tests per se. Nonetheless, the authors feel that it offers the greatest ability to discern a true benefit of screening, while minimizing the numerous potential biases that can be present in this type of study.

• 한국수학교육학회지시리즈D:수학교육연구
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• 제25권1호
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• pp.45-63
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• 2022

Multicultural students are a rapidly growing population in South Korea. Previous studies from the South Korean mathematics education community have reported low mathematics achievement levels of this population compared to Korean-born students. However, a systematic literature review was hardly employed. This study aims to synthesize the factors that affect the mathematics achievement of multicultural students to provide directions for future research and practical directions. Using an Opportunity-Propensity framework suggested by Byrnes and Miller, this study analyzed twenty-seven peer-reviewed journal articles on this topic. The results showed that the majority of the studies focused on the impact of the opportunity factors such as mathematics curriculum and teachers on mathematics achievements. We suggest that more studies regarding distal factors (e.g., students' prior achievement) and propensity factors (e.g., prerequisite knowledge) are needed.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제10권6호
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• pp.2627-2647
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• 2016

With the rapid growth of microblog, expert identification on microblog has been playing a crucial role in many applications. While most previous expert identification studies only assess global authoritativeness of a user, there is no way to differentiate the authoritativeness in a particular aspect of topics. In this paper, we propose a novel model, which jointly models text and following relationship in the same generative process. Furthermore, we integrate a similarity-based weight scheme into the model to address the popular bias problem, and use followee topic distribution as prior information to make user's topic distribution more precisely. Our empirical study on two large real-world datasets shows that our proposed model produces significantly higher quality results than the prior arts.

• 디지털산업정보학회논문지
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• 제12권4호
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• pp.135-143
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• 2016

The purpose of this study is to investigate the user's attitude and usage of smart banking application in terms of user's benefits and personalization. While the prior researches on mobile banking adoption focus on the characteristics of service itself, this paper intends to investigate the smart banking application in terms of user's benefits, which are personal value consumers attach to the product or service attributes. Based on prior studies functional benefits, social benefits, experiential benefits, and personalization are identified as affecting factors of the user's attitude and usage of smart banking application. According to the results of multiple regression analysis, all benefit factors(functional benefit, experimental benefit, social benefit) and personalization were found to be significantly related to the user's attitude. Users' attitude on smart banking was found to be significantly related to the real usage as well. This paper has value in that it investigates the attitude and usage of smart banking in terms of benefits.

• 응용통계연구
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• 제22권3호
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• pp.607-616
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• 2009

In many epidemiological studies, the occurrence times of the event of interest are right-censored or interval censored. In certain situations such as the AIDS data, however, the incubation period which is the time between HIV infection and the diagnosis of AIDS is usually doubly censored. In this paper, we impute the interval censored HIV infection time using three imputation methods. Mid imputation, conditional mean imputation and approximate Bayesian bootstrap are implemented to obtain right censored data, and then Gibbs sampler is used to estimate the coefficient factor of the incubation period. By using Bayesian approach, flexible modeling and the use of prior information is available. We applied both parametric and semi-parametric methods for estimating the effect of the covariate and compared the imputation results incorporating prior information for the covariate effects.

• 기술혁신연구
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• 제7권1호
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• pp.78-97
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• 1999

This study aims at analysing the role of crisis in the technological innovation. It has been taken for granted that organizational crisis has detrimental effects on the survival of organizations. But recent studies showed that organizational crisis has positive effects on organizational learning. They argued that crisis would provide a opportunities for reflecting the effectiveness of existing organizational routine. This study analyses the process and role of crisis in the development of CDMA mobile communication system and argues that crisis has effects on technological innovation when organizations have prior knowledge base which can be exploited in organizational learning. Secondly, it is argued that crisis can result in organizational transformation which facilitates organizational learning by integrating prior knowledge base and new knowledge. Thirdly, it is suggested that crisis may be good facilitator for organizational learning in case of competence-enhancing innovation rather than competence-destroying innovation.

• 한국군사과학기술학회지
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• 제22권5호
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• pp.667-673
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• 2019

We present an orienteering problem with unknown stochastic reward(OPUSR) model for persistent monitoring tasks with unknown event probabilities at each point of interest. Prior studies on orienteering problem for persistent monitoring task assume that rewards and event probabilities are known as a prior. In this paper, we propose a stochastic reward model with unknown event statistics and a path re-planning algorithm based on Bayesian reward inference. Experiments demonstrate the efficiency of our method.