• 제목/요약/키워드: Evidence Theory

검색결과 581건 처리시간 0.027초

Representing Fuzzy, Uncertain Evidences and Confidence Propagation for Rule-Based System

  • Zhang, Tailing
    • 한국농업기계학회:학술대회논문집
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    • 한국농업기계학회 1993년도 Proceedings of International Conference for Agricultural Machinery and Process Engineering
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    • pp.1254-1263
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    • 1993
  • Representing knowledge uncertainty , aggregating evidence confidences , and propagation uncertainties are three key elements that effect the ability of a rule-based expert system to represent domains with uncertainty . Fuzzy set theory provide a good mathematical tool for representing the vagueness associated with a variable when , as the condition of a rule , it only partially corresponds to the input data. However, the aggregation of ANDed and Ored confidences is not as simple as the intersection and union operators defined for fuzzy set membership. There is, in fact, a certain degree of compensation that occurs when an expert aggregates confidences associated with compound evidence . Further, expert often consider individual evidences to be varying importance , or weight , in their support for a conclusion. This paper presents a flexible approach for evaluating evidence and conclusion confidences. Evidences may be represented as fuzzy or nonfuzzy variables with as associat d degree of certainty . different weight can also be associated degree of certainty. Different weights can also be assigned to the individual condition in determining the confidence of compound evidence . Conclusion confidence is calculated using a modified approach combining the evidence confidence and a rule strength. The techniques developed offer a flexible framework for representing knowledge and propagating uncertainties. This framework has the potention to reflect human aggregation of uncertain information more accurately than simple minimum and maximum operator do.

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RISK-INFORMED REGULATION: HANDLING UNCERTAINTY FOR A RATIONAL MANAGEMENT OF SAFETY

  • Zio, Enrico
    • Nuclear Engineering and Technology
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    • 제40권5호
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    • pp.327-348
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    • 2008
  • A risk-informed regulatory approach implies that risk insights be used as supplement of deterministic information for safety decision-making purposes. In this view, the use of risk assessment techniques is expected to lead to improved safety and a more rational allocation of the limited resources available. On the other hand, it is recognized that uncertainties affect both the deterministic safety analyses and the risk assessments. In order for the risk-informed decision making process to be effective, the adequate representation and treatment of such uncertainties is mandatory. In this paper, the risk-informed regulatory framework is considered under the focus of the uncertainty issue. Traditionally, probability theory has provided the language and mathematics for the representation and treatment of uncertainty. More recently, other mathematical structures have been introduced. In particular, the Dempster-Shafer theory of evidence is here illustrated as a generalized framework encompassing probability theory and possibility theory. The special case of probability theory is only addressed as term of comparison, given that it is a well known subject. On the other hand, the special case of possibility theory is amply illustrated. An example of the combination of probability and possibility for treating the uncertainty in the parameters of an event tree is illustrated.

베이즈주의에서의 증거 개념 (Bayesian concept of evidence)

  • 이영의
    • 논리연구
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    • 제8권2호
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    • pp.33-58
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    • 2005
  • 오래된 증거의 문제는 가설이 제안되기 이전에 이미 알려진 증거는 그 가설을 입증할 수 없다는 문제를 제기한다. 오래진 증거의 문제는 베이즈적 입증 개념에 심각한 문제를 제기하는데 그것은 관련 학자들의 많은 노력에도 불구하고 여전히 미해결의 상태로 남아있다. 이 글의 목적은 오래된 증거의 문제가 베이즈적 입증 개념에 대한 심각한 오해에서 비롯되었다는 점을 보임으로써 그 문제를 해결하는 것이다. 먼저 논의의 출발점인 오래된 증거의 문제가 분석되고 이어서 베이즈주의자들이 그 문제를 해갈하기 위해서 제안한 두 가지의 대표적 입장이 비판적으로 검토된다. 이러한 과정을 통하여 오래된 증거의 문제에 대한 기존의 논의들에서 공통적으로 발견되는 오해, 즉 설명과 예측의 맥락에서 나타나는 입증의 비대칭성이 무시되는 현상이 지적된다. 마지막으로 입증의 비대칭성을 이용하여 두 종류의 구별되는 베이즈적 입증 개념이 제시되고 오래된 증거의 문제에서 가정된 입증은 진정한 입증이 아니라는 점이 주장된다.

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과학적 증거와 설명에 대한 초등학교 6학년 학생의 이해 (Sixth Graders' Inquiry Understanding for Scientific Evidence and Explanation)

  • 정혜선;오은아
    • 한국과학교육학회지
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    • 제23권6호
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    • pp.634-649
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    • 2003
  • 본 연구는 초등학생들의 과학적 증거와 설명에 대한 이해 진단을 목적으로 하였다. 과학적 증거의 수집, 자료의 객관성, 증거의 관련성, 자료 해석, 지식과 증거, 반복 관찰 이렇게 6개의 하위 탐구 능력이 Jeong, Songer와 Lee(2002)가 미국의 6학년 학생들의 과학적 탐구 능력을 측정하기 위해 개발한 문항을 사용하여 진단되었다. 춘천시에 소재한 초등학교 6학년 학생들을 대상으로 자료를 수집한 결과, 전체적으로 약 절반에 해당하는 학생들에게서 체계적인 과학적 사고 능력이 결여되어 있음이 드러났다. 특히 학생들은 지식과 관련되는 구체적인 예나 증거를 연결하는 것을 어려워했고, 반복관찰의 개념에 대해 잘 모르고 있는 것으로 나타났다. 본 연구에 참가한 학생들의 수가 적고 지역적 특성으로 인해 본 연구의 결과를 우리나라 초등학생의 전반적 과학적 탐구 능력으로 일반화하기는 어렵지만, 본 연구의 결과는 초등학생의 과학적 탐구 능력이 아직 만족할 만한 수준은 아니며, 이들의 탐구력 신장을 위해서 체계적인 노력이 필요함을 시사한다.

학교에서 진화론과 함께 지적설계론도 가르쳐야 하는가 (Do We Have to Teach Intelligent Design along with Evolution in Public Schools?)

  • 송광한
    • 한국융합학회논문지
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    • 제9권8호
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    • pp.185-198
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    • 2018
  • 본 논문은 학교에서 진화론과 함께 지적 설계론도 가르쳐야 한다는 요구가 강해지고 있는 상황에서 그에 대한 판단의 이론적 기초 자료로 활용하기 위한 목적으로 쓰였다. 진화론과 달리 경험적 증거가 거의 없는 지적 설계론이 과학이론이 될 가능성을 검증하기 위해 문헌들을 통해 지능이 무엇인지 밝히고, 그 지능의 흔적이 실제 자연 속에서 발견되고 있는지를 확인해 보았다. 자연에서 지능의 흔적인 '지적 요소'가 경험적으로 발견되면 지적 설계론도 과학이론으로서 인정받게 되어 진화론과 함께 학교 교육의 대상이 될 수 있지만 그렇지 않다면 논쟁할 가치조차 없어지게 된다. 지금까지 지능에 대한 문헌들을 종합한 결과 지능의 정체와 그 흔적을 찾을 수 있었으며, 그 흔적이 사고, 지식, 문명 등 인간으로부터 비롯된 다양한 인위적 산물에서 뿐만 아니라 자연의 모든 현상에서도 발견되고 있음이 확인되었다. 이런 결과를 바탕으로 본 논문은 진화론과 지적 설계론 간의 첨예한 대립과 갈등의 문제를 해결할 방법과 함께 진화론과 지적 설계론이 학교교육의 현장에서 어떻게 다루어져야 되는지에 대한 논의를 제공하고 있다.

지식확산에 의한 감염병 실험실의 자율적 생물안전관리 학습조직 설계 및 실행 (Design and Implementation of a Learning Organization for Autonomous Biosafety Management of Infectious Disease Laboratories by Knowledge Translation)

  • 신행섭;유민수
    • 한국환경보건학회지
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    • 제41권2호
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    • pp.102-115
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    • 2015
  • Objectives: A learning organization was designed and implemented on the basis of the selection criteria and essential elements of knowledge translation theory. Methods: The learning organization was designed on the basis of biosafety harmonization criteria and risk management strategy and was implemented as the learning organization for biosafety management by the National Institute of Health, Korea Centers for Disease Control & Prevention. The effect of knowledge translation in the research institutions by evidence-based policy was verified. Results: The result of applying the knowledge translation theory involving all stakeholders showed a positive reaction in establishing and implementing biosafety management strategy and embodied risk assessment criteria and evoked sympathy with the necessity of learning and using of expert knowledge about risk assessment and risk management. All stakeholders initiated voluntarily action toward new human-network construction and communication between similar organizations. The learning organization's capability expanded the base of knowledge translation. Conclusion: These results showed that a learning organization could enhance the autonomous safety management system by diffusion of knowledge translation.

Development of an Effective Strategy to Teach Evolution

  • Ha, Min-Su;Cha, Hee-Young
    • 한국과학교육학회지
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    • 제31권3호
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    • pp.440-454
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    • 2011
  • This study proposes a new instructional strategy and corresponding materials designed from various alternative frameworks to help students understand evolution as a biologically acceptable theory. Biology teachers have normally taught the evolutionary mechanism by means of comparing Lamarckism with natural selection. In this study, a new instructional strategy in which the Lamarckian explanation is first excluded because Lamarckism is known to be subsumed in a learner's cognitive structure as a strong preconception of evolution is suggested for teaching evolution. After mutation theory is introduced, Darwinism including natural selection is explained separately during the next class hour. Corresponding instructional materials that aid student understanding of the evolutionary mechanism were developed using recently published articles on human genetic traits as scientific evolutionary evidence instead of the traditional evolutionary subject matter, giraffe neck. Evolutionary evidence from human genetic traits allows students to exclude anthropocentric thoughts effectively and raise concern for the phenomenon of evolution positively. The administered instructional strategy and materials in this research improved student conception, concern, and belief of evolution and it is believed that they helped students understand the evolutionary mechanism effectively.

Involvement of Board Chairmen in Audit Committees and Earnings Management: Evidence from Malaysia

  • AL-ABSY, Mujeeb Saif Mohsen;ISMAIL, Ku Nor Izah Ku;CHANDREN, Sitraselvi;AL-DUBAI, Shehabaddin Abdullah A.
    • The Journal of Asian Finance, Economics and Business
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    • 제7권8호
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    • pp.233-246
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    • 2020
  • This paper investigates the effect of the involvement of the board chairman in the audit committee (AC) on earnings management (EM). It examines Bursa Malaysia-listed companies with the lowest positive earnings for the years 2013 to 2015. The Modified Jones Model by Kasznik (1999) was used to determine discretionary accruals. An AC that includes its board chairman as an ordinary member is associated with greater discretionary accruals. However, a board chairman who is also the chairman of the AC does not seem to influence discretionary accruals. This paper supports the agency theory and policy-makers' efforts to prevent board chairmen from sitting on ACs. It is the first study that uses the agency theory to describe the association between the board chairman's involvement in the both AC and EM. This study alerts policy-makers, stakeholders and researchers to the influence of a board chairman serving on the AC in curbing EM. Furthermore, it provides empirical evidence that the majority of Malaysian companies whose board chairmen are involved in the AC appoint the chairman as an ordinary member of the AC. This indicates that executive directors may affect such actions. Hence, more policies are needed to improve AC independence.

Political Connections and CSR Disclosures in Indonesia

  • SARASWATI, Erwin;SAGITAPUTRI, Ananda;RAHADIAN, Yan
    • The Journal of Asian Finance, Economics and Business
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    • 제7권11호
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    • pp.1097-1104
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    • 2020
  • This research seeks to provide evidence about how political connections, proxied by government ownership and the existence of politically connected board members, affect the extent of corporate social responsibility (CSR) disclosures in Indonesian listed companies. This research uses the legitimacy theory as a basis for explaining management's motivation for disclosing its CSR. The sample consists of 131 firm-year observations from 38 non-financial public companies that published sustainability reports from 2013 to 2017. We measured the CSR disclosures using a disclosure checklist on the sustainability reports. We subsequently processed the data using a random effect (RE) linear regression. The result shows that CSR disclosures were greater in government-owned companies but lower in companies that have politically connected board members. The results support the legitimacy theory that the government intends to demonstrate legitimate national economic and political conditions by showing that government-owned companies are sustainable. However, CSR disclosures seem to have a substitutive relationship with the existence of politically connected board members, since those political connections may protect the company from public pressure and/or the risk of litigation, reducing the need for CSR disclosures. This research provides evidence that different types of political connections may have different impacts on corporate disclosures.

본국 정부지원이 기업의 국제화 성과에 대한 효과: 중국기업을 대상으로 한 실증적 연구 (The Effects of Home Country Government Support on International Business Performance: Evidence from Chinese Firms)

  • 장약남;오한모
    • 아태비즈니스연구
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    • 제9권1호
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    • pp.91-106
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    • 2018
  • An appreciable number of Chinese firms have successfully expanded their businesses into foreign economics although they have limited resources. Advocating that home country government supports can mitigate firms' resource-disadvantages in international expansions, we attempted to investigate whether and how the Chinese government's support enables Chinese firms to compete in foreign markets. Based heavily on the knowledge-based theory of the firm and the resource-based theory of the firm, we developed a model that explain and predicts the effects of home-country government-supports on superior financial performance. The model was empirically tested using a accounting dataset regarding Chinese firms' 323 international expansion events from 2008 to 2015. Empirical evidence presents that the Chinese government's support has a positive effect on Chinese firms' international success and that these firms' marketing, technological, and managerial resources positively moderate the effect of the government support on the firms' international success. Nonetheless, because we employed an event-study method, the limitations of the method can be applied to the current research. In addition, because of the empirical context, the results of the research might lack generalizability. We, however, provided an understanding how firms from emerging countries can succeed in international expansions specifically when they have lack of resources for international competition.

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