• Proceedings of the Korean Information Science Society Conference
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• 2005.07b
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• pp.784-786
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• 2005

본 논문에서는 웹 문서의 논리적 구조분석을 위한 전처리 과정으로서 웹 문서에 포함된 잡음 영역을 제거하는 클리닝 방법을 제안한다. 제안된 방법은 잡음 영역을 내비게이션 영역, 광고 영역, 상호작용 영역, 특수정보 영역, 그리고 스크립트/스타일 영역의 5종류로 구분한 후, 이를 제거할 수 있는 규칙을 제안한다. 제안된 방법의 성능을 평가하기 위하여 웹으로부터 추출된 726개의 다양한 문서를 대상으로 실험한 결과 $91.16\%$ 확률을 보였다.

• Korean Journal of Logic
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• v.18 no.1
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• pp.83-133
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• 2015

In this paper, I pose a problem for Hitchcock's arguments for two concepts of effects that are intended to explicate double causal effects, and put forth a theory that is intended not just to meet the problem but also to accommodate Hitchcock's theory and Eells' theory both. First, I introduce an example of dual causal effects, and examine the accounts of Otte(1985) and Eells(1987) on how to explicate the dual effects. I show that their accounts of the dual effects help us understand the problem of dual effects and see how different it is for Cartwright(1979, 1989, 1995), Eells(1991, 1995), and Hitchcock(2001a) to meet the problem. Second, I introduce two concepts of effects on Hitchcock(2001a), that is, net effect and component effect that are allegedly analogous to two effects of structural equation model. Third, I reveal the significance of homogeneous subpopulation and causal interaction regarding the problem of dual effects while examining Cartwright's theory and Elles' theory. Fourth, I critically examine the two concepts of effects on Hitchcock and argue against Hitchcock's criticism of Eells' theory. Fifth, I take a moderator variable of structural equation model and a moderator effect into the probabilistic theory of causality, and formally generalize causal interaction due to the dual effects in terms of disjunctive relation and counterfactual conditionals. I expect my account of disjunctive relation and counterfactual conditionals to contribute not just to several problems the received theories of causal modelling confront but also to the structural equation models many people exploit as a promising statistical methodology.

• Korean Journal of Logic
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• v.20 no.1
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• pp.1-19
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• 2017

In modern cosmology, it is controversial whether the existence of human consciousness can be used as evidence to support the hypothesis that many parallel universes are actualized. In this paper, we want to explore the nature of self-consciousness information that I am awake now. Consider the following experiment participating Al and Bob. We throw a fair coin on Sunday. If the coin lands heads we wake up just one of Al and Bob on Monday. If the coin lands tails we wake up both of Al and Bob. On Monday, at least one of Al and Bob will wake up, to what degree ought they believe that the outcome of the coin toss is heads? We will argue that the correct answer to this question is 1/3. To this end, we will argue the awakened person's information that "I am awake" is given to himself through a random procedure.

• Korean Journal of Logic
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• v.17 no.1
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• pp.109-136
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• 2014

Every (semantic) antirealist accepts one or another form of verification principle. The principle has strong and weak forms, the strong form being highly counterintuitive but the weak one being more plausible. Understandably, antirealists have preferred the weak form of verification principle. Unfortunately, the socalled knowability paradox shows that those two forms are indeed equivalent. To solve this problem, Edgington suggests a yet new form of verification principle. Unfortunately, her new principle has its own difficulty. To overcome this difficulty, Edgington provides a new model of knowledge, according to which every true proposition is somehow associated with a known counterfactual conditional. In this paper, I shall argue that even this new model of knowledge confronts with an insurmountable problem. It is a well-known fact that, in the microscopic levels, some facts manage to occur despite very low physical chances. I will argue that the counterfactuals linked with those facts cannot be known due to the existence of epistemic defeaters. Hence, Edgington's knowledge model does not work in all cases.

• Korean Journal of Logic
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• v.22 no.1
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• pp.1-23
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• 2019

Gott, Carter, Leslie, Bostrom and so on, as Descartes did, have made the evidence that is "I am here as an observer" to support many other beliefs. Bostrom and others who studied observation selection effects are missing two points. First, the self-consciousness information of the ones who just came up is distinct from that of the ones who have awoken. The awoken 'I' can trace back by memory to the past, but the 'I' who just came up can not. Second, when calculating credence, we must distinguish the ones in the possible worlds from the ones in the actual worlds. An estimate of credence where only one possible world is actualized among all possible worlds, differs fundamentally from that where all possible worlds are actualized. Keeping these two points in mind, we have explored what is the nature of the self-consciousness information of the one who just came up. We examine in depth the two human embryos thought experiment.

• Journal of Educational Research in Mathematics
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• v.15 no.3
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• pp.315-334
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• 2005

The purpose of this study is to find out the implications on when and how the correlation concept can be taught. we investigate the development time and method of the concept in a statistical perspective those initially have discussed in psychology by Piaget. We first reviewed the 1958 research by Inhelder and Piaget. It was the first one which researched the development of the correlation and has become the foundation of psychological perspective. According to them, the correlation concept needs proportional and probability concept ahead of its development and argued on the coefficient of correlation based on formal and logical position. However, from a statistical perspective, the correlation concept is a part of the distribution concept. So, the level of the correlation concept grows from the comparison of conditional distributions to the conditional probability distribution where the proportional concept and probability concept are applied. As reviewed through the literature, we found that 11-12 years old students in early formal operation stage reasoned about correlation through the comparison of conditional distributions. In our study, we argue that we need to consider the possibility of beginning didactic mediation for correlation concept earlier and the method approaching it in a distribution perspective.

• Science of Emotion and Sensibility
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• v.20 no.2
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• pp.149-160
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• 2017

In hypothesis testing, the interpretation of a statistic obtained from the data analysis relies on a probabilistic distribution of the statistic constructed according to several statistical theories. For instance, the statistical significance of a mean difference between experimental conditions is determined according to a probabilistic distribution of the mean differences (e.g., Student's t) constructed under several theoretical assumptions for population characteristics. The present study explored the logic and advantages of random-resampling approach for analyzing event-related potentials (ERPs) where a hypothesis is tested according to the distribution of empirical statistics that is constructed based on randomly resampled dataset of real measures rather than a theoretical distribution of the statistics. To motivate ERP researchers' understanding of the random-resampling approach, the present study further introduced a specific example of data analyses where a random-permutation procedure was applied according to the random-resampling principle, as well as discussing several cautions ahead of its practical application to ERP data analyses.

• Journal of Korean Society of Transportation
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• v.27 no.3
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• pp.111-118
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• 2009

Factors causing traffic accidents are various and traffic law violations can be among them. The efforts to increase traffic law obedience rates of drivers are common in many other countries to reduce traffic accidents, and one of generally applied methods is to increase the amounts of violation fines. Expensive levels of traffic law violation fines could have drivers choose "obey the law" in their decision-making stages since they are economically better-off by following the law. In this sense, this study has developed an economic model to verify whether the current levels of the traffic violation fines of Korea are effective for drivers to choose "obey-the-law" decisions. Speed violations and traffic signal violations have been selected for the case study to verify the relationships between "expected probabilities of being-caught" and "levels of violations fines".

• Journal of the Korean Institute of Gas
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• v.1 no.1
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• pp.81-86
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• 1997

This study is to estimate the possibility of accident in chemical plants from the analysis of system component which affects the occurrence of top event. Among the various risk assessment techniques, the Fault Tree Analysis which approaches deductively on the route of accident development was used in this study. By gate-by-gate method and minimal cut set, the qualitative and quantitative risk assessment for hazards in plants was performed. The probability of occurrence and frequency of top event was calculated from failure or reliability data of system components at stage of the quantitative risk assessment. In conclusion, the probability of accident was estimated according to logic pattern based on the Fault Tree Analysis. And the failure path which mostly influences on the occurrence of top event was found from Importance Analysis.

• Proceedings of the KSR Conference
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• 2007.05a
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• pp.605-613
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• 2007

In order to overcome the difficulties of quantitative risk analysis such as complexity of model, we propose a systematic methodology for risk quantification of railway system which consists of 6 steps: The identification of risk factors, the determination of major scenarios for each risk factor by using event tree, the development of supplementary fault trees for evaluating branch probabilities, the evaluation of event probabilities, the quantification of risk, and the analysis in consideration of accident situation. In this study, in order to address the feasibility of the propose methodology, this framework is applied to the prototype risk model of nation-wide railway level crossings. And the quantification result based on the data of 2005 in Korea will also be presented.