• Korean Journal of Logic
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• v.12 no.2
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• pp.89-114
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• 2009

We have many causal beliefs, and they play an important role in our decision making. Unlike evidential decision theory, causal decision theory claims that an account of rational choice must use causal beliefs to identify the considerations that make a choice rational. I claim that evidential decision theory is refuted by the original Newcomb's problem but not by the medical Newcomb problem. The latter is taken to be the best example to point out the weakness of evidential decision theory. However, by the explicit statement about causal relations, I argue that the medical Newcomb problem loses its strength in refuting evidential decision theory. With this argument, this paper clarifies the difference between evidential decision theory and causal decision theory.

• Journal of The Korean Association For Science Education
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• v.36 no.4
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• pp.551-561
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• 2016

The purpose of this study is to investigate both theoretically and empirically the roles of models in abductive reasoning for scientific problem solving. The context of the study is design-based research the goal of which is to develop inquiry learning programs in the domain of earth science, and the current article dealt with an early process of redesigning an abductive inquiry activity in geology. In the theoretical study, an extensive review was conducted with the literature addressing abduction and modeling together as research methods characterizing earth science. The result led to a tentative scheme for modeling-based abductive inference, which represented relationships among evidence, resource models, and explanatory models. This scheme was improved by the empirical study in which experts' reasoning for solving a geological problem was analyzed. The new scheme included the roles of critical evidence, critical resource models, and a scientifically sound explanatory model. Pedagogical implications for the support of student reasoning in modeling-based abductive inquiry in earth science was discussed.

• Annual Conference on Human and Language Technology
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• 1989.10a
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• pp.296-301
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• 1989

본 논문의 목적은 매개변항(parameter)과 부분집합원리(subset principle)를 재귀대명사 구조분석 및 습득에 적용하여 보편문법(Universal Grammar)과 언어습득의 상호관계를 검토하는 데에 있다. 본 논문은 첫째, 재귀대명사 '자기'를 매개변항이론에 근거하여 분석하고, 둘째, 재귀사의 구조를 부분집합원리에 적용하여 '자기'의 습득과정을 관찰한다. 본 논문의 목적을 위해 두 가지 가설을 세워 실험적으로 검증하였다. 실험결과, 선행사자격 습득단계의 가설이 확증되었으며, 지배변항 습득단계의 가설은 결정적 증거가 미비해 앞으로의 과제로 남아 있다.

• Science of Emotion and Sensibility
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• v.5 no.1
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• pp.17-24
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• 2002

This research was the first step to develop Expert System for Evaluation of Human Sensibility, where human sensibility can be inferred from objective physiological signals. The study aim was to develop an algorithm in which human arousal level can be judged using measured physiological signals. Fuzzy theory was applied for mathematical handling of the ambiguity related to evaluation of human sensibility, and the degree of belonging to a certain sensibility dimension was quantified by membership function through which the sensibility evaluation was able to be done. Determining membership function was achieved using results from a physiological signal database of arousal/relaxation that was generated from imagination. To induce one final result (arousal level) based on measuring the results of more than 2 physiological signals and the membership function of each physiological signal, Dempster-Shafer's Rule of Combination in Evidence was applied, through which the final arousal level was inferred.

• Management & Information Systems Review
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• v.39 no.3
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• pp.83-98
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• 2020

This study analyzes how investors' irrational behavior (or pessimistic sentiment) affects stock market returns and investors' market activity using mass media that delivered public information from January 1998 to December 2012 as a sample. According to pessimistic investor theory, investor pessimism leads to downward pressure on the price of equity capital, thereby making market sentiment pessimistic and lowering market yields. It also shows that investor pessimism increases transaction costs in the market, which in turn dampens investors' trading activities. In other words, pessimistic reporting on public information disseminated by mass media induces investors to act irrationally, eventually having a direct impact on the stock market. This study conducted an empirical analysis of the existing theoretical and empirical studies using domestic mass media as a sample. First, the study revealed a negative correlation between pessimistic reporting and returns as well as excess returns, while it did not show statistically significant results. Second, evidence has been suggested that pessimistic sentiment in the stock market has a negative impact on future pessimistic reporting by mass media. Third, the analysis of the impact of pessimistic reporting on investors' market activity using proxy variables for various market activities found that pessimism dampens market activity, while it did not show statistically significant results. It is assumed that low statistical significance is due to the fact that sample collection was carried out on a monthly basis. While the results of the study have low statistical significance, statistical signs support predictions of the theory.

• Korean Journal of Crystallography
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• v.10 no.2
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• pp.110-113
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• 1999

x의 범위가 0.5

• Journal of Distribution Research
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• v.16 no.3
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• pp.33-75
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• 2011

The ownership structure of a franchise system is determined by the franchisor's strategic choice. A close look at the extant theories and perspectives in economics and management such as resource scarcity theory, agency theory, transaction cost analysis, and mixed ownership theory reveals that firms choose their ownership structure for the sake of economic efficiency, profit potentials, the chance of survival, and other strategic concerns. The present study, on the basis of strategic choice perspective, reviews the divergent theories of a franchise system's ownership structure and its determinants, thus providing a theoretical framework for comparing the contradictory arguments along the several critical dimensions. We also developed and tested the conflicting hypotheses regarding key determinants of ownership structure including firm's age, size, transaction-specific investments, uncertainty, and risk-sharing propensity. Using a FDD (Franchise Disclosure Document) data set of 543 Korean franchisors, we found that the years in business, the total number of employees, days of training, the inverse of the years of franchising, and the requirement of royalty payment have positive relationships with the proportion of company-owned outlets to total number of outlets. On the other hand, the proportion of company-owned outlets was found to have negative relationships with the total number of outlets and the extent of geographic dispersion of outlets, but to have no significant relationships with the initial investment required and the inverse of contract length. Based on the findings, we provide several theoretical and managerial implications for studying ownership structure of franchise systems.

• The Korean Journal of Financial Management
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• v.25 no.2
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• pp.33-68
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• 2008

The purpose of this paper is to test the market timing hypothesis and impact of macro economic variables on capital structure choice as well as the traditional static trade-off and pecking order theories of capital structure in a integrated framework. Through a two stage test of target capital structure and capital structure choice, none of theories was consistently supported, but most of them were partly supported. In the first stage analysis of target ratio, coefficients of firm-specific variables generally supported the predictions of pecking order theory rather than those of the static trade-off theory. However, the result of the second stage test on capital structure choice supported the hypothesis of the static trade-off theory, which claims that firms usually set and pursue the target leverage ratio. Further, the result of the seconde stage shows that a simple pecking oder theory does not hold because firms with deficit of internal fund tend to issue bonds rather than stocks to raise outside fund. Also, the result indicates that the market timing hypothesis holds because firms with over-valued stocks tend to issue stocks rather than bonds. However, contrary to Korajczyk and Levy(2003), the impact of macro economic variables such as term or credit spreads on capital structure choice was negligible, and the impact of macro economic and market timing hypothesis variables were not greater in financially unconstrained firms as Korajczyk and Levy(2003) suggested.

• Informatization Policy
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• v.27 no.4
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• pp.47-66
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• 2020

The rapid development of artificial intelligence technologies such as machine learning and deep learning is expanding its impact in the public administrative and public policy sphere. This paper is an exploratory study on policy decision-making in the age of artificial intelligence to design automated configuration and operation through data analysis and algorithm development. The theoretical framework was composed of the types of policy problems according to the degree of problem structuring, and the success and failure cases were classified and analyzed to derive implications. In other words, when the problem structuring is more difficult than others, the greater the possibility of failure or side effects of decision-making using artificial intelligence. Also, concerns about the neutrality of the algorithm were presented. As a policy suggestion, a subcommittee was proposed in which experts in technical and social aspects play a professional role in establishing the AI promotion system in Korea. Although the subcommittee works independently, it suggests that it is necessary to establish governance in which the results of activities can be synthesized and integrated.

• The Korean Journal of Financial Management
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• v.12 no.1
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• pp.33-56
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• 1995

본(本) 연구(硏究)는 자본구조이론과 전통적 연구에서 제시된 변수를 통합하고 횡단면(橫斷面) 요인(要因)과 시계열(時系列) 요인(要因)을 결합하여 우리나라의 자본구조결정 요인을 식별할 수 있는 이론적(理論的) 모형(模型)을 제시하여, 또한 제시된 모형을 한국증권시장(韓國證券市場)의 자료(資料)를 이용하여 실증적(實證的)으로 분석(分析)하였다. 그리고 실증적 분석에는 횡단면(橫斷面) 자료(資料)와 시계열(時系列) 자료(資料)를 결합하는 패널자료추정법(資料推定法)을 사용하였다. 본(本) 연구(硏究)에서 제시된 자본구조이론(資本構造理論)과 관련된 결정 요인으로는 기업(企業)의 성장기(成長機)을, 내부주주(內部株主)의 지분율(持分率) 그리고 내부주주수(內部株主數)의 비율 등을, 전통적 횡단면 요인으로는 경영위험(經營危險), 자산구성(資産構成), 수익성(收益性), 기업규모(企業規模) 등을, 그리고 전통적 시계열 요인으로는 법인세율(法人稅率)과 물가수준(物價水準) 등을 제시하였다. 본(本) 연구(硏究)에서 다루는 실증분석기간은 1981년 1월부터 1990년 12월까지의 10년간이었으며, 추출된 표본기업(標本企業)의 수(數)는 104개사이다. 실증적 분석결과, 본(本) 연구(硏究)에서 제시된 설명변수들이 자본구조(資本構造)의 변동(變動)을 49.91%정도 설명하고 있으며 설명변수 중 기업(企業)의 성장기회(成長機會), 내부주주(內部株主)의 지분을, 경영위험(經營危險), 수익성(收益性), 기업규모(企業規模), 물가수준(物價水準) 등은 자본구조의 결정 요인으로 통계적인 의미를 갖는 변수로 밝혀졌으며 회귀계수(回歸係數)의 부호도 기대하였던 바와 일치하고 있다. 질산으로 처리된 것이 컸고 0.75 M과 1.0 M의 질산을 사용했을 때는 작음이 확인되었다. 이상의 실험결과들로부터 친수성인 $NH_4Y$형 제올라이트를 소수성의 것으로 변환시키기 위한 수증기의 온도는 $500^{\circ}C$와 $600^{\circ}C$가, 그리고 질산의 농도는 0.5 M이 적합한 것으로 결론지을 수 있고, 이와 같은 결론은 BET비표면적과 TPV값과 같은 경향을 보인 벤젠과 톨루엔의 흡착용량측정결과로 입증되었다. 탈알루미늄된 제올라이트들의 수분에 대한 Si/Al비와 흡착용량은 각각 높은 농도의 질산으로 처리된 것일수록 증가하고 감소하여 소수성이 증가함을 나타내었다.(不適合性)이 나타났다. 본 연구는 기존의 기대수익률(期待收益率) 위주의 요일효과(曜日效果) 분석에서 주식수익률(株式收益率)의 분산(分散) 즉, 변동성(變動性)에 촛점을 두어 분석하였으며, 이는 투자자의 정확한 위험측정(危險測定)수단의 제공이라는 면에서 의의(意義)가 있을 것으로 생각된다.據金) 운용(運用)에 관한 정책수립시(政策樹立時) 금융선진국(金融先進國)의 증거금(證據金) 정책운용(政策運用)을 통한 시장관리(市場管理) 경험(經驗)을 어느 정도 참고할 수 있음을 시사한다고 할 것이다. 한다. 실증분석결과는 본문의 <표 1>에 제시되어 있으며 그 내용을 간략하게 요약하면 다음과 같다. (A) 실증분석모형 : 본 연구에서는 다기간 자산가격결정모형중에서 대표적인 Lucas (1978)모형을 직접 사용한다. $$1={\beta}\;E_t[\frac{U'(C_{t+1})\;P_t\;s_{t+1}}{U'(C_t)