• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2004년도 ICCAS
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• pp.1302-1306
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• 2004

This paper proposes a model for information filtering (IF) on the Web. The user information need is described into two levels in this model: profiles on category level, and Boolean queries on document level. To efficiently estimate the relevance between the user information need and documents by fuzzy, the user information need is treated as a rough set on the space of documents. The rough set decision theory is used to classify the new documents according to the user information need. In return for this, the new documents are divided into three parts: positive region, boundary region, and negative region. We modified user profile by the user's relevance feedback and discerning words in the documents. In experimental we compared the results of three methods, firstly is to search documents that are not passed the filtering system. Second, search documents that passed the filtering system. Lastly, search documents after modified user profile. The result from using these techniques can obtain higher precision.

• 유통과학연구
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• 제14권2호
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• pp.41-45
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• 2016

Purpose - Finding an optimal path is an essential component for the design and operation of smart transportation or logistics network. Many applications in navigation system assume that travel time of each link is fixed and same. However, in practice, the travel time of each link changes over time. In this paper, we introduce a new transportation problem to find a latest departing time and delivery path between the two nodes, while not violating the appointed time at the destination node. Research design, data, and methodology - To solve the problem, we suggest a mathematical model based on network optimization theory and a backward search method to find an optimal solution. Results - First, we introduce a dynamic transportation problem which is different with traditional shortest path or minimum cost path. Second, we propose an algorithm solution based on backward search to solve the problem in a large-sized network. Conclusions - We proposed a new transportation problem which is different with traditional shortest path or minimum cost path. We analyzed the problem under the conditions that travel time is changing, and proposed an algorithm to solve them. Extending our models for visiting two or more destinations is one of the further research topics.

• 의학교육논단
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• 제22권2호
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• pp.85-92
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• 2020

The purpose of this study is to discuss the main principles and concepts of social constructivism, examine the literature on the application of social constructivism in medical education, and explore the meaning and limitations of the utilization of social constructivism with learning theory. A literature search was carried out in two stages, utilizing PubMed, CINAHL and Education Source databases. The first search included both fields (social constructivism AND medical education), while the second search was performed by subject (Vygotsky or ZPD or zone of proximal development or scaffolding AND medical education). A total of 96 papers were found through the first and second searches, and after reviewing the abstracts of all 96 papers, 41 papers were deemed suitable for research purposes. In medical education, social constructivism is applied in areas such as (1) social and cultural behaviors (hidden curriculum), (2) social construct of "meaning" (dialogue and discourse), (3) learner's identity transformation (expert), and (4) instructional intervention (ZPD and scaffolding). Social constructivism has provided many ideas to explore in terms of the composition of knowledge in the sociocultural context of health care, but it has not demonstrated an explicit instructional method or educational effects.

• Journal of Information Science Theory and Practice
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• 제2권3호
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• pp.6-17
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• 2014

The purpose of this study is to examine to what extent the context in which people interact with online information affects people's credibility perceptions. In this study, credibility assessment is defined as perceptions of credibility relying on individuals' expertise and knowledge. Context has been characterized with respect to three aspects: Context as user goals and intentions, context as topicality of information, and context as information activities. The data were collected from two empirical studies. Study 1 was a diary study in which 333 residents in Michigan, U.S.A. submitted 2,471 diary entries to report their trust perceptions associated with ten different user goals and nine different intentions. Study 2 was a lab-based study in which 64 subjects participated in performing four search tasks in two different information activity conditions - information search or content creation. There are three major findings of this study: (1) Score-based trust perceptions provided limited views of people's credibility perceptions because respondents tended to score trust ratings consistently high across various user goals and intentions; (2) The topicality of information mattered more when study subjects assessed the credibility of user generated content (UGC) than with traditional media content (TMC); (3) Subjects of this study exerted more effort into making credibility judgments when they engaged in searching activities than in content creation. These findings indicate that credibility assessment can or should be seen as a process-oriented notion incorporating various information use contexts beyond simple rating-based evaluation. The theoretical contributions for information scientists and practical implications for web designers are also discussed.

• 정보관리학회지
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• 제8권1호
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• pp.100-116
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• 1991

본 연구에서는 지식베이스의 용어간 관계와 증거추론이론을 이용한 정보검색 시스템을 설계하였다. 실험을 위한 문헌파일은 한국전자통신연구소의 통신분야 기술문서를 대상으로 작성하였으며, 지식베이스는 INSPEC 시소러스의 통신분야 용어 및 용어간 관계들을 발췌하여 구성하였다. 그리고 용어간의 관련성은 용어간 관계의 종류에 따라 수치로 표현하였으며, 이들 수치를 이용하여 뎀스터-셰이퍼 이론에 따라 질문과 문헌간의 관련성을 추론, 산출하였다. 실험결과 질문의 탐색어외에도 관련된 용어의 확장검색을 통하여 포괄적인 검색을 할 수 있었으며, 용어간 관계를 반영하여 질문과 문헌간의 관련성을 산출하고, 관련성 순위에 따라 검색결과를 제시할 수 있었다.

• 한국군사과학기술학회지
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• 제15권5호
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• pp.601-614
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• 2012

Since the optimized use of sonar systems available for detection is a very practical problem for a given ocean environment, the measure of mission achievability is needed for operating the sonar system efficiently. In this paper, a theory on Measure Of Effectiveness(MOE) for specific mission such as detection is described as the measure of mission achievability, and a recursive Cumulative Detection Probability(CDP) algorithm is found to be most efficient from comparing three CDP algorithms for discrete glimpses search to reduce computation time and memory for complicated scenarios. The three CDPs which are MOE for sonar-maneuver pattern are calculated as time evolves for comparison, based on three different formula depending on the assumptions as follows; dependent or independent glimpses, unimodal or non-unimodal distribution of Probability of Detection(PD) as a function of observation time interval for detection. The proposed CDP algorithm which is made from unimodal formula is verified and applied to OASPP(Optimal Acoustic Search Path Planning) with complicated scenarios.

• 대한수학교육학회지:수학교육학연구
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• 제18권1호
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• pp.1-24
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• 2008

본 논문에서는 수학적 지식의 구성에 대한 구성주의자들의 설명이 안고 있는 문제점을 드러내고, 이를 보완할 수 있는 방안을 모색하고자 하였다. 이를 위해 마음의 중층구조의 틀로 지식의 구성 능력과 구성 작용 간의 관계를 고찰하고, 수학적 지식의 구성은 수학적 지식이 반영하는 실재로서의 위층의 마음을 경험하고 드러내는 일로 규정하였다. 구조주의와 구성주의의 대립과 관련을 성리학에서 주리론과 주기론의 대립과 관련에 비추어 논하고, 수학적 지식의 구성은 수학적 지식의 구조를 구성하는 것이어야 함을 논하였다. 수학적 지식의 구조의 구성이 구체적으로 어떤 과정을 통해 이루어질 수 있는가 하는 문제에 답하기 위하여 본 논문에서는 폴라니의 인식론을 고찰하고, 수학화 이론과 역사-발생적 원리, 수학적 사고 수준 이론을 수학적 지식의 구조의 구성 과정에 대한 이론으로 재해석하였다. 끝으로, 수학적 지식의 구조의 구성을 위한 학생과 교사의 자세와 역할에 대하여 논의하였다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1997년도 한국자동제어학술회의논문집; 한국전력공사 서울연수원; 17-18 Oct. 1997
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• pp.60-64
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• 1997

Designing fuzzy controller, there are difficulties that we have to determine fuzzy rules and shapes of membership functions which are usually obtained by the amount of trial-and-error or experiences from the experts. In this paper, to overcome these defects, genetic algorithms which is probabilistic search method based on genetics and evolution theory are used to determine fuzzy rules and fuzzy membership functions. We design a series compensation fuzzy controller, then determine basic structures, input-output variables, fuzzy inference methods and defuzzification methods for fuzzy controllers. We develop genetic algorithms which may search more accurate optimal solutions. For evaluating the fuzzy controller performances through experiments upon an actual system, we design the fuzzy controllers for the speed control of a DC series motor with nonlinear characteristics and show good output responses to reference inputs.

• 소성∙가공
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• 제16권2호
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• pp.138-143
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• 2007

Superplastic forming/diffusion bonding (SPF/DB) processes were analyzed using a 3-D rigid visco-plastic finite element method. A constant-triangular element based on membrane approximation and an incremental theory of plasticity are employed for the formulation. The coulomb friction law is used for interface friction between tool and material. Pressure-time relationship for a given optimal strain rate is calculated by stress and pressure values at the previous iteration step. In order to improve the contact searching, hierarchical search algorithm has been applied and implemented into the code. Various geometries including sandwich panel and 3 sheet shape for 3-D SPF/DB model are analyzed using the developed program. The validity fer the analysis is verified by comparison between analysis and results in the literature.

• 한국정보과학회논문지:시스템및이론
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• 제26권3호
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• pp.282-290
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• 1999

본 논문에서는 영상 데이터베이스에서의 색인화를 위해 화소간의 엔트로피(inter-pixel entropy)측면에서 영상을 해석하여 특징을 추출하는 색인기법을 제안하였다. 엔트로피를 정량적으로 나타내기 위하여 PIM(picture information measure)에 기반한 특징을 각각의 영상들로부터 추출하여 색인으로 사용하였다. 엔트로피에 기반 하는 특징은 한 영상에 대하여 3가지를 추출하였다. 첫 번째 특징은 원 영상으로부터 직접 값들을 추출하였고 영상의 해상도와 그레이 레벨을 낮추어 가면서 얻어지는 영상들로부터 두 번째, 세번째 의 엔트로피 특징을 각각 추출하였다. 일반적으로 영상의 경우에 엔트로피가 높은 영역에 정보가 집중되는 경향이 있고 엔트로피가 낮은 영역에서는 배경 영역 등의 정보를 추출하게된다. 이러한 이유로 색채 특쟁은 엔트로피에 따라서 분리된 영역에서 추출하였다. 전역검색(global search)은 엔트로피 특징을 이용하였고 색채 특징을 이용하여 지역 검색(local search)을 시도하였다. 실험은 색채와 엔트로피로 식별이 유용한 꽃 영상을 사용하였는데 원치 않는 영상이 상위 단계에서 나타나는 빈도가 기존의 타 기법에 비해 줄어들었다.