• Title/Summary/Keyword: 증거 추론

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Uncertainty Data Reasoning Considering User Preferences Based on Dempster-Shafer Theory (사용자 성향을 고려한 Dempster-Shafer Theory 기반의 불확실한 데이터 추론)

  • Kim, Hee-Seong;Kang, Hyung-Ku;Youn, Hee-Yong
    • Proceedings of the Korean Information Science Society Conference
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    • 2012.06b
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    • pp.510-512
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    • 2012
  • 상황인식 서비스 분야에서 불확실한 데이터를 추론하는 것은 매우 어렵고 복잡하다. 이러한 상황정보들에서 얻어지는 데이터는 불확실성을 내포하고 있어서 불확실한 추론 결과를 초래할 수 있다. 비록 불확실성 문제들을 해결하기 위해 퍼지 이론, 뉴런 네트워크, 동적 베이지안 네트워크, 은닉 마르코프 모델과 같은 여러 종류의 방법들이 제시되었지만 이러한 방법들은 가설들을 하나의 숫자에 의해 신뢰의 정도를 표시하기 때문에 많은 어려움이 있다. 본 논문에서는 사용자들이 제공받는 서비스들에 대하여 만족도를 평가한 후 수집된 데이터를 활용하여 사용자들의 상관 관계를 분석한다. 그리고 Dempster-Shafer 이론을 사용하여 사용자들로부터 측정된 믿음 값을 융합한다. 이는 불확실성 값을 낮추어 추론결과의 정확성을 높이고 증거구간을 재설정하여 사용자들에게 신뢰성 있는 적응형 서비스를 제공하게 한다.

Investigation of Elementary Students' Scientific Communication Competence Considering Grammatical Features of Language in Science Learning (과학 학습 언어의 문법적 특성을 고려한 초등학생의 과학적 의사소통 능력 고찰)

  • Maeng, Seungho;Lee, Kwanhee
    • Journal of Korean Elementary Science Education
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    • v.41 no.1
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    • pp.30-43
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    • 2022
  • In this study, elementary students' science communication competence was investigated based on the grammatical features expressed in their language-use in classroom discourse and science writings. The classes were designed to integrate the evidence-based reasoning framework and traditional learning cycle and were conducted on fifth graders in an elementary school. Eight elementary students' discourse data and writings were analyzed using lexico-grammatical resource analysis, which examined the discourse text's content and logical relations. The results revealed that the student language used in analyzing data, interpreting evidence, or constructing explanations did not precisely conform to the grammatical features in science language use. However, they provided examples of grammatical metaphors by nominalizing observed events in the classroom discourses and those of causal relations in their writings. Thus, elementary students can use science language grammatically from science language-use experiences through listening to a teacher's instructional discourses or recognizing the grammatical structures of science texts in workbooks. The opportunities in which elementary students experience the language-use model in science learning need to be offered to understand the appropriate language use in the epistemic context of evidence-based reasoning and learn literacy skills in science.

The Method on Value Evaluation of IS using CBR (CBR을 활용한 정보시스템의 가치평가 방법에 관한 연구)

  • Park Ki-Nam;Kim Jong-Weon
    • Proceedings of the Korea Society for Industrial Systems Conference
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    • 2006.05a
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    • pp.63-73
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    • 2006
  • 대부분의 CEO들은 대규모 투자가 선행되는 정보시스템의 화폐적 가치에 확신을 가지고 싶어 한다. 지금까지 MIS 연구자들은 정보시스템의 조직적 성과에 관한 여러 가지 간접적인 증거를 보여주었으나 경영자들이 요구하는 정보시스템에 대한 화폐적 확신을 주는데 실패하였다. 본 연구는 최근 각 기업들이 도입하고 있는 BSC의 성과지표 중 정보시스템 관련 지표를 활용하여 기업의 계량적 및 비계량적 성과측정을 활용함으로써 조직의 정보시스템 성과를 화폐가치로 환산할 수 있는 방법을 제시하고자 한다. 이때 사례기반추론 시스템을 활용하면 사례베이스로부터 유사사례를 도출하고 이를 통하여 정보시스템 도입에 필요한 주요 정보를 추론할 수 있게 되어 조직에서 도입할 정보시스템의 잠재적 화폐가치를 어느 정도 가늠할 수 있다. 본 연구는 정보시스템의 화폐적 가치분석을 위하여 실물옵션 가격결정모형을 활용하였고 객관적 화폐가치 추론을 위한 웹 사이트 구축을 목표로 한다.

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Development of Arousal Level Estimation Algorithm by Membership Function and Dempster-Shafer′s Rule of Combination in Evidence (소속함수와 Dempster-Shafer 증거합 법칙을 이용한 긴장도 평가 알고리즘 개발)

  • 정순철
    • 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.

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Rule-based Detection of Vehicles in Traffic Scenes (교통영상에서의 규칙에 기반한 차량영역 검출기법)

  • Park, Young-Tae
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.37 no.3
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    • pp.31-40
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    • 2000
  • A robust scheme of locating and counting the number of vehicles m urban traffic scenes, a core component of vision-based traffic monitoring systems, is presented The method is based on the evidential reasoning, where vehicle evidences m the background subtraction Image are obtained by a new locally optimum thresholding, and the evidences are merged by three heuristic rules using the geometric constraints The locally optimum thresholding guarantees the separation of bright and dark evidences of vehicles even when the vehicles are overlapped or when the vehicles have similar color to the background Experimental results on diverse traffic scenes show that the detection performance is very robust to the operating conditions such as the camera location and the weather The method may be applied even when vehicle movement is not observed since a static Image IS processed without the use of frame difference.

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Rainfall Frequency Analysis and Uncertainty Quantification Using Dempster-Shafer Theory (Dempster-Shafer 이론을 이용한 강우빈도분석 및 불확실성의 정량화)

  • Seo, Young-Min;Jee, Hong-Kee;Lee, Soon-Tak
    • Proceedings of the Korea Water Resources Association Conference
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    • 2010.05a
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    • pp.1390-1394
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    • 2010
  • Dempster-Shafer 이론은 미지의 매개변수 추정시 베이지안 기법의 제약을 완화시키기 위한 베이지안 접근법의 일반화로 해석될 수 있으며, 상호배타적인 싱글톤에만 확률이 할당되는 것이 아니라 가능한 결과의 부분집합들이 기본확률할당을 위한 대상으로 고려된다. 베이지안 접근은 우연적 불확실성 및 지식의 불확실성을 효율적으로 구분할 수 없으며, 특정도가 낮고 애매한 증거들을 다룰 수 없는 반면, Dempster-Shafer 증거추론은 이러한 문제들을 효율적으로 평가할 수 있다. 따라서 본 논문에서는 홍수위험평가 및 수자원 계획 수립시 가장 기본이 되는 강우빈도해석에서 확률분포의 매개변수에 대한 불확실성 고려한 확률강우량의 산정 및 불확실성의 영향을 평가하기 위하여 Dempster-Shafer 이론을 이용하여 불확실성을 고려한 강우빈도해석모델 구축 및 적용을 통해 홍수위험평가 및 수자원 계획 등에 있어서 불확실성 표현 및 처리기법을 제시하였다.

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Analysis of Student Science Writing and Perception on Argument-Based Claim and Evidence Writing Approach (논의를 강조한 주장과 증거 글쓰기 수업을 경험한 학생들의 과학 주제 글쓰기 및 인식 분석)

  • Park, Sunyoung;Choi, Aeran
    • Journal of The Korean Association For Science Education
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    • v.34 no.8
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    • pp.787-794
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    • 2014
  • The purpose of this study was to examine the science writing and perception of students who experienced the argument-based claim and evidence writing approach. One hundred and eight grade 11 students were assigned to an experimental group, while 99 grade 12 students were assigned to a comparative group in their earth science classes. Students' science writings on two science topics were scored using an analytic rubric developed in this study. The comparison of experimental and comparative groups in science writing was carried out using an independent two samples t-test. Students' perception on the instruction was examined using an open-ended survey. Science writing by the experimental group scored significantly higher than that by the comparative group, except for the big idea of 'green energy'. For six concepts in 'green energy' and four concepts in 'plate tectonics, there were more students in the experimental group than the comparative group who indicated them in their science writing. Students' perception on the instruction was positive in that they mentioned planning and conducting inquiry, citing of claims and evidence, and developing inquiry questions were helpful in science learning. The results of this study imply that the argument-based claim and evidence writing approach should be implemented in science classrooms for students to develop a conceptual framework for science.

Development and Application of the Scientific Inquiry Tasks for Small Group Argumentation (소집단의 논변활동을 위한 과학 탐구 과제의 개발과 적용)

  • Yun, Sun-Mi;Kim, Heui-Baik
    • Journal of The Korean Association For Science Education
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    • v.31 no.5
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    • pp.694-708
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    • 2011
  • In this study, we developed tasks including cognitive scaffolding for students to explain scientific phenomena using valid evidences in science classroom and sought to investigate how tasks influence the development of small group scientific argumentation. Heterogeneous small groups in gender and achievement were organized in one classroom and the tasks were applied to the class. Students were asked to write down their own ideas, share individual ideas, and then choose the most plausible opinion in a group. One group was chosen for investigating the effect of tasks on the development of small group argumentation through the analysis of discourse transcripts of the group in 10 lessons, students' semi-structured interview, field note, and students' pre- and post argument tests. The discrepant argument examples were included in the tasks for students to refute an argument presenting evidences. Moreover, comparing opinion within the group and persuading others were included in the tasks to prompt small group argumentation. As a result, students' post-argument test grades were increased than pre-test grades, and they argued involving evidences and reasoning. The high level of arguments has appeared with high ratio of advanced utterances and lengthening of reasoning chain as lessons went on. Students had elaborate claims involving valid evidences and reasoning by reflective and critical thinking while discussing about the tasks. In addition, tasks which could have various warrants based on the data led to students' spontaneous participation. Therefore, this study has significance in understanding the context of developing small group argumentation, providing information about teaching and learning context prompting students to construct arguments in science inquiry lessons in middle school.

Understanding Bayesian Statistics

  • Jeong, Yun-Sik
    • Proceedings of the Korean Statistical Society Conference
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    • 2002.11a
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    • pp.61-68
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    • 2002
  • 통계학은 불확실성(uncertainty)에 대한 연구이다. 베이지안 통계 방법은 불확실성 아래서 통계 추론과 의사 결정 모두를 위한 완전한(complete) 패러다임을 제공한다. 베이지안 방법론은 합리적인 초기 정보와 결합하는 것을 가능하게 만들고, 전통적인 통계적 방법론에 의하여 직면하는 많은 어려움들을 풀 수 있는 coherent 방법론을 제공하면서 엄격한 수학적 기본에 근거하고 있다. 베이지안 패러다임은 일반적인 용어로써 확률이란 단어의 사용을 가장 잘 어울리게 하는 불확실성의 조건부 측도(conditional measure of uncertainty)로써 확률의 해석에 근거한다. 관심있는 것에 대한 통계적 추론은 증거의 관점에서 그 값에 대한 불확실성의 변형으로써 묘사되며, 베이즈 정리(Bayes' theorem)는 이러한 변형이 어떻게 만들어지는 가를 자세히 설명할 수 있다. 베이지안 방법들은 전통적인 통계적 방법론에 접근할 없는 복잡하고, 다양한 구조적 문제들에 응용할 수 있다.

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A Novel Method of Basic Probability Assignment Calculation with Signal Variation Rate (구간변화율을 고려한 기본확률배정함수 결정)

  • Suh, Dong-Hyok;Park, Chan-Bong
    • The Journal of the Korea institute of electronic communication sciences
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    • v.8 no.3
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    • pp.465-470
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    • 2013
  • Dempster-Shafer Evidence Theory is available for multi-sensor data fusion. Basic Probability Assignment is essential for multi-sensor data fusion using Dempster-Shafer Theory. In this paper, we proposed a novel method of BPA calculation with signal assessment. We took notice of the signal that reported from the sensor mote at the time slot. We assessed the variation rate of the reported signal from the terminal. The trend of variation implies significant component of the context. We calculated the variation rate of signal for reveal the relation of the variation and the context. We could reach context inference with BPA that calculated with the variation rate of signal.