• 제목/요약/키워드: Evidence theory

검색결과 581건 처리시간 0.021초

Application of Joint Electro-Chemical Detection for Gas Insulated Switchgear Fault Diagnosis

  • Li, Liping;Tang, Ju;Liu, Yilu
    • Journal of Electrical Engineering and Technology
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    • 제10권4호
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    • pp.1765-1772
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    • 2015
  • The integrity of the gas insulated switchgear (GIS) is vital to the safety of an entire power grid. However, there are some limitations on the techniques of detecting and diagnosing partial discharge (PD) induced by insulation defects in GIS. This paper proposes a joint electro-chemical detection method to resolve the problems of incomplete PD data source and also investigates a new unique fault diagnosis method to enhance the reliability of data processing. By employing ultra-high frequency method for online monitoring and the chemical method for detecting SF6 decomposition offline, the acquired data can form a more complete interpretation of PD signals. By utilizing DS evidence theory, the diagnostic results with tests on the four typical defects show the validity of the new fault diagnosis system. With higher accuracy and lower computation cost, the present research provides a promising way to make a more accurate decision in practical application.

Dempster-Shafer 증거 이론을 이용한 배전계통 보호도 평가 (Protection Level Evaluation of Distribution Systems Based on Dempster-Shafer Theory of Evidence)

  • 김희철;이승재;강상희;안복신;박종국
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1998년도 하계학술대회 논문집 C
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    • pp.896-898
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    • 1998
  • Recent development of the digital computer and communication technology has made the concept of the adaptive protection possible, which is to adapt the operating parameters of the protective devices to the system changes, so that the best protection function can be maintained all the time. In order to achieve the adaptive protection, it is necessary to have the way to determine whether the change of the settings is needed under the certain system change or how good the current protection level is. This paper proposed the protectability index, which is a way to evaluate the protection level of the system under arbitary conditions and the operating strategy of the adaptive protection utilizing this index. It is based on an hierachical evaluation model and the evidence combination rule of the Dempster-Shafer theory.

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The Nexus Between Monetary Policy and Economic Growth: Evidence from Vietnam

  • NGUYEN, Hoang Chung
    • The Journal of Asian Finance, Economics and Business
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    • 제9권1호
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    • pp.153-166
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    • 2022
  • The study estimates the Structured VAR and the Dynamic Stochastic General Equilibrium Model for the Vietnamese economy based on the new Keynesian model for small and open economies, with the output gap, inflation, policy interest rate, the Vietnamese exchange rate, and the inflation and interest rate in the United States. The paper aims to clarify the impulse response of the macro variables through their shocks. It offers to model the SVAR and DSGE processes, as well as describe why and how interest rate policy is important in the impulse response of macro variables like the output gap and inflation process. The study supports the central role of monetary policy by giving empirical evidence for the new Keynesian theory, according to which an interest rate shock causes the output gap to widen and inflation to decrease. Finally, the application of the DSGE model is becoming more and more popular in the State Bank of Viet Nam to improve its policy planning, analyzing, and forecasting policy towards sustainable and stable growth.

포렌식에서 디지털 증거의 우선순위 스케쥴링 (Priority Scheduling of Digital Evidence in Forensic)

  • 이종찬;박상준
    • 한국정보통신학회논문지
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    • 제17권9호
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    • pp.2055-2062
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    • 2013
  • 범죄 증거의 새로운 형태인 디지털 증거는 기존의 증거와 기능 및 역할에 있어서 거의 차이점이 없으며, 증거로서의 법적 인정 및 역할이 점차 증가할 것으로 예상된다. 포렌식 수사관은 다수의 증거 보유 장치(예, 컴퓨터 시스템, 저장 매체 등)에 저장되어 있는 막대한 양의 데이터로부터, 사건과 관련된 실마리를 찾기 위하여 많은 시간을 소모해야 한다. 따라서 조사 시간을 단축하기 위해서는 잠재적인 관련 증거의 중요성에 근거하여 순서화 및 순위화가 필요하다. 본 연구에서는 포렌식 조사 시에, 정확한 증거를 선정하게 함으로서 증거 분석 우선순위를 결정하는 방법을 제안한다. 제안된 방식은 증거 조사 소요시간, 증거의 가치, 증거간의 연관성 그리고 사건과 시간과의 연관성과 같은 다수의 부정확한 요소가 퍼지 집합 함수를 사용한 의사 결정에 사용되는 다기준 의사 결정에 근거한다.

Improved Dynamic Subjective Logic Model with Evidence Driven

  • Qiang, Jiao-Hong;Xin, Wang-Xin;Feng, Tian-Jun
    • Journal of Information Processing Systems
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    • 제11권4호
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    • pp.630-642
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    • 2015
  • In Jøsang's subjective logic, the fusion operator is not able to fuse three or more opinions at a time and it cannot consider the effect of time factors on fusion. Also, the base rate (a) and non-informative prior weight (C) could not change dynamically. In this paper, we propose an Improved Subjective Logic Model with Evidence Driven (ISLM-ED) that expands and enriches the subjective logic theory. It includes the multi-agent unified fusion operator and the dynamic function for the base rate (a) and the non-informative prior weight (C) through the changes in evidence. The multi-agent unified fusion operator not only meets the commutative and associative law but is also consistent with the researchers's cognitive rules. A strict mathematical proof was given by this paper. Finally, through the simulation experiments, the results show that the ISLM-ED is more reasonable and effective and that it can be better adapted to the changing environment.

Corporate Social Responsibility and Financial Performance in Korean Retail Firms

  • Lee, Jeong-Hwan;Kang, Yun-Sik;Kim, Sang-Su
    • 유통과학연구
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    • 제16권5호
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    • pp.31-43
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    • 2018
  • Purpose - We examine how a Korean retail firm's social responsibility is related to its financial performances. The traditional view of corporation expects a negative relationship, while the stakeholder theory expects a positive one. Research design, data, and methodology - We adopt the ESG score, published by Korean Corporate Governance Service to measure the level of socially responsible activity for the Korean retail firms. The ordinary least square method is adopted to investigate this relationship. The publicly traded retail firms are examined from 2011 to 2016. Results - We find that the total ESG score is negatively related to ROE but shows no statistically significant relationship with ROA and Tobin's Q value. However, a firm's environmental score is negatively related with both of ROE and ROA. Its social score is no conclusive relationship with the performance measures. The governance score is negatively related to the value of Tobin's Q. Conclusions - This paper generally supports the traditional view of corporate theory, especially in terms of ROE. This evidence is not well aligned with the existing study for Korean corporations generally documenting positive relationships. We find almost no empirical evidence supporting the stakeholder theory of corporation in the Korean retail industry.

사후확률 결합에 의한 분류정확도 향상에 관한 연구 (A study on classification accuracy improvements using orthogonal summation of posterior probabilities)

  • 정재준
    • Spatial Information Research
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    • 제12권1호
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    • pp.111-125
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    • 2004
  • 위성영상 분류에 관한 주요 주제 중 하나는 분류 정확도 향상에 있다. 동일지역에 대한 동일시기의 위성영상을 취득할 수 있는 기회가 많아지는 현실을 감안할 때, 복수의 위성영상 데이터를 이용하여 분류정확도가 향상된 분류결과를 도출하는 것은 의미 있는 일일 것이다. 본 연구 주제는 최대우도법을 사용하여 계산된 데이터의 사후확률 및 분류 불확실도를 Dempster-Shafer의 증거이론에 적용하여 분류정확도를 향상시키고자 하는 것이다. 분석결과 개별적인 데이터 분류나 데이터간 융합에 의한 분류보다 본 연구에서 제안한 방법이 전체정확도와 Kappa 지수 모두 높은 정확도를 나타냈으며, 정확도 차에 대한 검정을 실시하여 본 연구에서 제안한 방법이 다른 방법에 비해 우수함을 통계적으로 증명하였다.

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A Systematic Review Exploring the Current State of Fashion Criticism -A Focus on the Fashion Designer Exhibition Reviews of Fashion Theory-

  • Choi, Kyung-Hee
    • 한국의류학회지
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    • 제44권2호
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    • pp.273-294
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    • 2020
  • Considering the complex relationship between fashion curating and the critical approach of fashion exhibition reviews, this study explores the current state of fashion criticism in museology, focusing on fashion designer exhibition reviews of Fashion Theory. The author selected eighteen exhibition reviews of individual fashion designers' works from 1997 on to the current 2020 issues of Fashion Theory, which provides an interdisciplinary forum to analyze fashion as a cultural construction. The author performed a systematic review that qualitatively summarizes and/or synthesizes the findings of the studies on the topic with the process of a systematic review, such as key question formulation, analytic framework building, evidence mapping, critical appraisal, and evidence synthesis. The results of this study are as follows. First, the exhibition reviews included almost all stages of the inclusive fashion criticism model, based on an artifact study. Second, they reflected various critical discourses that offered current interpretations of historical and contemporary fashion. Third, they showed that fashion criticism in the museum context is the result of an interdisciplinary collaboration of various fashion agents. Finally, they offered a bridge for crossing the boundaries of various scholarly fields, as they combine multidisciplinary scholarship with object-based methods.