• The Korean Journal of Applied Statistics
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• v.30 no.5
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• pp.615-632
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• 2017

Unlike randomized trial, statistical strategies for inferring the unbiased causal relationship are required in the observational studies. The matching with the propensity score is one of the most popular methods to control the confounders in order to evaluate the effect of the treatment on the outcome variable. Recently, new methods for the causal inference in latent class analysis (LCA) have been proposed to estimate the average causal effect (ACE) of the treatment on the latent discrete variable. They have focused on the application study for the real dataset to estimate the ACE in LCA. In practice, however, the true values of the ACE are not known, and it is difficult to evaluate the performance of the estimated the ACE. In this study, we propose a method to generate a synthetic data using the propensity score in the framework of LCA, where treatment and outcome variables are latent. We then propose a new method for estimating the ACE in LCA and evaluate its performance via simulation studies. Furthermore we present an empirical analysis based on data form the 'National Longitudinal Study of Adolescents Health,' where puberty as a latent treatment and substance use as a latent outcome variable.

• Korean Journal of Social Welfare
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• v.57 no.1
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• pp.193-217
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• 2005

Due to the increasing concerns with the North Korean defectors, the researches have been increased. When it is compared with other areas, the researches about the North Korean defectors are rare. The sample size of this study is 164, which makes it possible to do statistical inferences. As statistical methods, t-test, ANOVA and hierarchical multiple regressions are used. This study examines the effect of the adjustment stress and the social support on the depressive symptoms. Demographic factors such as gender, age and education are controlled. The context factors-the period of the stay in the third place, the period of residence and the existence of the education in Korea- are used as control variables. The research results show that the level of social participation of the women is higher than that of men. Also, there are differences of the functional social support by the age group. The research result indicates the education of South Korea is an important factor to reduce the depressive symptoms. The research result also shows that the jobless is an important stressor. Among structural social support, the member of religious or social group is an important factor for reducing depressive symptoms. Among functional social support, the emotional social support is an important factor of adaptation, but the effect of instrumental social support is the opposite. Therefore, the adequacy of social support in a specific situation must be considered.

• Korean Journal of Culture and Social Issue
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• v.21 no.2
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• pp.177-203
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• 2015

The aims of this study were 1) to compare irrational gambling beliefs of gamblers and non-gamblers, 2) to investigate the role of cognitive error on winning probability thinking error, and 3) to examine the relationship between attributional bias and gambling behavior. A total of 248 subjects were recruited for this study. All subjects were classified into non-gamblers, social gamblers and pathological gamblers, and administered self-report questionnaires to measure irrational gambling beliefs, the probability inference error, the attriburional style, and the attributional bias. A pathological gambler group scored highest on irrational gambling beliefs, especially the overestimation of self-ability factor, and a social gambler group and a non-gambler group follow. All three groups scored higher on the magnification of gambling skills than the mean (4.0) of the scale. Pathological gamblers and social gamblers scored higher on the probability thinking error than non-gamblers. Pathological gamblers displayed higher external attribution, lower internal attribution in their daily life events and higher internal attribution in failure situation than social gamblers and non-gamblers. The results indicate that cognitive errors would be a factor that differentiates pathological gamblers from social gamblers and non-gamblers. In predicting gambling behaviors, overestimation of self-ability of irrational gambling beliefs, internal attribution in failure situation, external attribution in daily live event, and probability thinking error were identified as significant factors. It is concluded that a public education about common cognitive bias featured in gamblers might be important in prevention of pathological gambling behaviors.

• Journal of the Korean School Mathematics Society
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• v.12 no.1
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• pp.1-25
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• 2009

The purpose of this research is the investigation of mathematics pre service teachers' disposition. Their disposition will be used for preposition of preservice Leacher program for making pre service teachers' participate any program willingly and extend their thinking. For this research, the researcher collected various data from investigation-presentation, report for practice and beauty of mathematics, micro teaching, and peer-evaluation. Preservice teachers had positive attitude for mathematics. They described their feeling, thinking and reflection about various methods of instruction and prefer to have micro teaching. They described that the investigation-presentation was needed to change some. From the results, the teacher preparation program is needed to integrate theory and practice to make preservice teachers gain profound knowledge on pedagogical content knowledge by making them high their interest and sensitivity on mathematics.

• Proceedings of the Korean Information Science Society Conference
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• 2006.06b
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• pp.136-138
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• 2006

최근 이동통신 기술의 급격한 발전과 PPC(Pocket PC), 노트북 등의 휴대단말기의 보급 확산에 따라 위치기반 서비스(Location Based Service: LBS)가 주요한 응용분야고 부상하고 있다. 위치 정보에 대한 정확한 위치 추적 및 활용 방안에 대한 활발한 연구가 진행되고 있지만, 대부분 제공되는 서비스는 현재 사용자의 위치에 기반한 정적인 서비스를 제공하는 초보적인 단계에 있다. 이동경로는 사용자의 성향이나 상태를 반영하기 때문에 사용자의 이동패턴을 예측하거나, 사용자의 현재 상태를 추론하는데 도움을 줄 수 있다. 본 논문에서는 이동패턴에 따른 사용자의 의도를 예측하여 개별화 된 서비스 제공을 위해, RSOM(Recurrent Self Organizing Map)과 마르코프 모델을 단계적으로 구성하여 사용자의 이동패턴을 모델링하는 방법을 제안한다. 실제 연세대학교 캠퍼스 내에서 실제 대학원생의 생활을 모델로 GPS(Global Positioning System) 데이터를 수집하여. 이동패턴을 모델링하고 개별화된 서비스를 제공함으로써 제안하는 방법의 유용성을 검증하였다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.4
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• pp.304-310
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• 2017

This study is a methodological research study that tests the validity and reliability of the NCRC (Nurse Clinical Reasoning Competence scale), an instrument developed by Liou and his colleagues as the basic data for enhancing the clinical reasoning competence of nurses, by translating it into Korean and checking the similarity of the sentence structure and meaning (between the two versions?). This study verified its validity and reliability by examining 166 nurses working in four tertiary hospitals located in Seoul and Busan. An analysis of the content validity by experts showed that all of the items have a content validity higher than CVI 0.8. From the exploratory and confirmatory factor analysis, it was found that the instrument includes a total of 15 items consisting of one factor. In addition, the correlation with the Korean version of the Nurse Clinical Reasoning Competence scale is confirmed to test the concurrent validity, by using a measurement tool of nurses' critical thinking dispositions and clinical decision-making abilities (correlation coefficient =.55-.64(p<.001) and Cronbach's ${\alpha}=.93$). Thus, the Korean version of the NCRC may be a useful instrument for evaluating the clinical reasoning competence of Korean nurses and providing the basic data for assessing their clinical reasoning competence and developing their promotion strategies.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.10
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• pp.2232-2240
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• 2015

Recently in the field of Big Data, there is a trend of collecting and reprocessing the existing data such as products having high interest of customers and past purchase details to be utilized for the analysis of transaction propensity of users(product recommendations, sales forecasts, etc). Studies related to the propensity of previous users has limitations on its range of subjects and investigation timing and difficult to make predictions on detailed products with lack of real-time thus there exists difficult disadvantages of introducing appropriate and quick sales strategy against the trend. This paper utilizes the machine learning algorithm application to analyze the transaction propensity of users. As a result of applying the machine learning algorithm, it has demonstrated that various indicators which can be deduced by detailed product were able to be extracted.

• The Journal of the Korea Contents Association
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• v.17 no.5
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• pp.209-220
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• 2017

This study explores what are the factors which influence the perception of press professionalism and fairness of journalist in the process of their news production. This study focused on how the difference between mainstream media and online media, the political tendency and the degree of freedom during working effected on the judgement of the freedom of press based on the model of Shoemaker and Reese' hierarchical model. As a result, Research finding is as follows: First, online media journalist evaluated the fairness of press higher than offline media journalists. Second, the consistency of political tendency of offline media is different from online media. Online media journalists evaluated the fairness of the press higher than offline media journalists. Finally, the degree of freedom during performance is the most importance factor which affects the evaluation of press fairness. This study highlights the factors which influence the perception of journalists on the quality of the press based on the survey data which have conducted by Korean press foundation This study implicates how working environment is importance in journalist's writing as a journalist. The freedom of press is very important in the process of news production because the factors which influence the evaluation of the fairness and the professionalism of press reveals the quality of press.

• The KIPS Transactions:PartB
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• v.8B no.5
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• pp.485-492
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• 2001

Recently, character agents are used as a user-friendly interface. In this paper, we have studied a generic framework for emotional character agents which are designed to infer emotions from diverse personalities, situations, user behaviors and to express them. The method of emotion inference is based on blackboard systems which are used to solve the problems in AI. Because it keeps independence between knowledge sources which are rules of emotions, a blackboard-based inference engine is easy to manage knowledge sources, Blackboard-based systems gave the system flexibility. So we can adapt the engine to various application systems. Each emotional agent monitors user behavior, learns user profile and infers user behavior. And it generates characters emotions according to the user profile. So, in case of same situations, the agent can generate different emotions according to users. We have studied to build an personalized emotional character agent which according to situations and user modeling.

• Journal of Intelligence and Information Systems
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• v.10 no.3
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• pp.59-72
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• 2004

The range of Internet usage is drastically broadened and diversed from information retrieval and collection to many different functions. Contrasting to the increase of Internet use, the efficiency of finding necessary information is decreased. Therefore, the need of information system which provides customized information is emerged. Our research proposes Web Service based recommendation system which employes inference engine to find and recommend the most appropriate products for users. Web applications in present provide useful information for users while they still carry the problem of overcoming different platforms and distributed computing environment. The need of standardized and systematic approach is necessary for easier communication and coherent system development through heterogeneous environments. Web Service is programming language independent and improves interoperability by describing, deploying, and executing modularized applications through network. The paper focuses on developing Web Service based recommendation system which will provide benchmarks of Web Service realization. It is done by integrating inference engine where the dynamics of information and user preferences are taken into account.