• Title/Summary/Keyword: Evidence Theory

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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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    • v.10 no.4
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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.

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

  • Kim, He-Chul;Lee, Seung-Jae;Kang, Sang-Hee;Ahn, Bok-Shin;Park, Jong-Kuk
    • Proceedings of the KIEE Conference
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    • 1998.07c
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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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    • v.9 no.1
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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.

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

  • Lee, Jong-Chan;Park, Sang-Joon
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.17 no.9
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    • pp.2055-2062
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    • 2013
  • Digital evidence which is the new form of evidence to crime makes little difference in value and function with existing evidences. As time goes on, digital evidence will be the important part of the collection and the admissibility of evidence. Usually a digital forensic investigator has to spend a lot of time in order to find clues related to the investigation among the huge amount of data extracted from one or more potential containers of evidence such as computer systems, storage media and devices. Therefore, these evidences need to be ranked and prioritized based on the importance of potential relevant evidence to decrease the investigate time. In this paper we propose a methodology which prioritizes order in which evidences are to be examined in order to help in selecting the right evidence for investigation. The proposed scheme is based on Fuzzy Multi-Criteria Decision Making, in which uncertain parameters such as evidence investigation duration, value of evidence and relation between evidence, and relation between the case and time are used in the decision process using the aggregation function in fuzzy set theory.

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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    • v.11 no.4
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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
    • Journal of Distribution Science
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    • v.16 no.5
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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.

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

  • 정재준
    • Spatial Information Research
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    • v.12 no.1
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    • pp.111-125
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    • 2004
  • Improvements of classification accuracy are main issues in satellite image classification. Considering the facts that multiple images in the same area are available, there are needs on researches aiming improvements of classification accuracy using multiple data sets. In this study, orthogonal summation method of Dempster-Shafer theory (theory of evidence) is proposed as a multiple imagery classification method and posterior probabilities and classification uncertainty are used in calculation process. Accuracies of the proposed method are higher than conventional classification methods, maximum likelihood classification(MLC) of each data and MLC of merged data sets, which can be certified through statistical tests of mean difference.

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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
    • Journal of the Korean Society of Clothing and Textiles
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    • v.44 no.2
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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.