• International journal of advanced smart convergence
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• 제8권4호
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• pp.169-178
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• 2019

Due to the characteristics of an ad hoc network without a control center, self-organization, and flexible topology, the trust evaluation of the nodes in the network is extremely difficult. Based on the analysis of ad hoc networks and the blockchain technology, a blockchain-based node-level trust evaluation model is proposed. The concepts of the node trust degree of the HASH list on the blockchain and the perfect reward and punishment mechanism are adopted to construct the node trust evaluation model of the ad hoc network. According to the needs of different applications the network security level can be dynamically adjusted through changes in the trust threshold. The simulation experiments demonstrate that ad-hoc on-demand distance vector(AODV) Routing protocol based on this model of multicast-AODV(MAODV) routing protocol shows a significant improvement in security compared with the traditional AODV and on-demand multipath distance vector(AOMDV) routing protocols.

• 대한교통학회지
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• 제26권3호
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• pp.199-209
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• 2008

본 연구는 전통적인 중방향 설계시간교통량 산정에 대한 개념적 내용을 살펴보고 사례연구를 통해 문제점을 도출하였으며, 이를 개선하기 위해 확률적인 중방향 설계시간교통량 산정 모형을 이론적으로 정립하였다. 도로구간의 교통혼잡을 표현하기 위해서 도로용량이 희망하는 서비스수준을 수용할 수 있도록 확률 분포를 적용한 링크통행시간과 임계치를 정립하였다. 본 연구에서 제안된 확률적인 중방향 설계시간 교통량 모형은 설계속도, 구간길이, 교통량, 차로수, 중차량계수 등을 고려하여 산정하며, 도로용량에 따른 교통혼잡과 경제성 측면을 유동적으로 고려할 수 있기 때문에 도로계획 및 설계단계에 객관적으로 반영할 수 있다. 또한, 이러한 결과는 다양한 유형의 도로에 대해 결측치가 존재하는 상시조사지점이나 수시조사지점의 중방향 설계시간 교통량 예측 모형을 포함한 여러 현실문제들의 더 나은 이해를 제공할 수 있을 것으로 기대된다.

• 한국멀티미디어학회논문지
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• 제7권9호
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• pp.1312-1320
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• 2004

최근 다양한 시각적 특징 표현들이 연구되고 많은 시스템들이 만들어졌음에도 불구하고 기존의 내용기반 영상 검색 접근 방식들은 유음성에서 한계가 있었다. 특히 사용자의 고 수준개념들과 시스템의 저 수준 특징 사이의 차이와 시각적 내용에 대한 인간의 유사성 인식의 주관성이 배제되는 한계를 지니고 있었다. 따라서 영상정보의 정확한 데이터 전달과 이를 효율적으로 검색하기 위한 방법이 요구된다. 적합성 피드백은 멀티미디어 검색에 있어 사용자가 요구하는 정보를 반영할 수 있어 영상의 검색 효율을 높일 수 있다. 본 논문에서는 기존의 적합성 피드백 기법의 성능을 향상시키기 위해 경계 값과 pre-fetching을 이용하여 긍정적 피드백과 부정적 피드백을 혼합한 개선된 영상 검색 기법을 제안한다. 또한, 제안된 피드백 기법을 이용하여 기존의 검색시스템을 보다 발전시킨 영상 검색 시스템을 구현한다.

• 보건행정학회지
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• 제19권4호
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• pp.98-120
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• 2009

The purpose of this study is to elicit preference for drug listing decision criteria and to estimate the ICER threshold in South Korea using the discrete choice experiment (DCE) method. To collect the data, a DCE survey was administered to a subject sample either educated in the principle concepts of pharmacoeconomics or were decision makers within that field. Subjects chose between alternative drug profiles differing in four attributes: ICER, uncertainty, budget impact and severity of disease. The orthogonal and balanced designs were determined through computer algorithm to take the optimal set of drug profiles. The survey employed 15 hypothetical choice sets. A random effect probit model was used to analyze the relative importance of attributes and the probabilities of a recommendation response. Parameter estimates from the models indicated that three attributes (ICER, Impact, Severity of disease) influenced respondents' choice significantly(p${\pm}$0.001). In addition, each parameter displayed an expected sign. The Lower the ICER, the higher the probability of choosing that alternative. Respondents also preferred low levels of uncertainty and smaller impact on health service budget. They were also more likely to choose drugs for serious diseases rather than mild or moderate ones. Uncertainty however is not statistically significant. The ICER threshold, at which the probability of a recommendation was 0.5, was 29,000,000 KW/QALY in expert group and 46,500,000 KW/QALY in industry group. We also found that those in our sample were willing to accept high ICER to get medication for severe diseases. This study demonstrates that the cost-effectiveness, budget impact and severity of disease are the main reimbursement decision criteria in South Korea, and that DCE can be a useful tool in analyzing the decision making process where a variety of factors are considered and prioritized.

• 품질경영학회지
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• 제40권4호
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• pp.441-452
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• 2012

Purpose: In this paper, we have considered a problem of newsvendor model in an environment of random yields in quality and customer balking behavior, in which only the mean and the variance of the demand are known. In practice, the distributional information of the demand is very limited and only the mean and variance are guessed by experience. In addition, due to the customers balking behavior occurring when the available inventory level decreases, the product's demand becomes a function of inventory level so that the classical newsvendor's optimal order quantity is no longer optimal. Methods: We have developed an optimal order quantity model that enables us to incorporate the random yield of a product and the customer balking information such as a threshold inventory level of balking and the corresponding probability of a sale during the balking. Results: We illustrated the concepts developed here through simple numerical examples and showed the robustness of our model in a various setting of parameters. Conclusion: This paper provides a useful analysis showing that our distribution-specific and distribution-free approach to the optimal order quantity in the newsboy model can act as an effective tools to match supply with demand for these product lines.

• 한국실내디자인학회논문집
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• 제14호
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• pp.90-98
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• 1998

At the threshold of the 21st century People have been exploring the future of each field. Accordingly In the area of housing the increase in income level and high-technology development facilitated full scale research on the future housing. The purpose of this research is to try to set up a systematic theory on the future housing by investigating theoretical backgrounds of the future housing and development of the future housing planning concept, A document research method was used to analyze the development of the future housing planning concept of three periods from its origin in the 19th century to present : the burgeoning period growing period and maturing period. In particulary this research examines development of the future housing planning concept from the 19th century in which future housing planning concept was emerged to the early part of the 20th century: the burgeoning period. The future housing planning concepts of this period are analyzed as follows ; In order to solve the social problems arising in the process of the Industrial Revolution, the concept such as ; "ideal city", "high rise apartment housing" and "industrialized housing" was formulated. housing" was formulated.ated.

• 인지과학
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• 제2권2호
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• pp.309-339
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• 1990

인간이 서로 통신하는 가장 일반적인 방법은 자연어로 말하거나 글로 나타내는 방법이다.그러나 현재 기술로는 컴퓨터를 사용하려면 인위적인 프로그램밍 언어를 별도로 습득하여만 한다.만약 컴퓨터가 사람들이 말하거나 또는 글로 나타낸 자연어들을 이해할 수 있다면 사람들은 월씬 더 쉽고 자연스럽게 컴퓨터를 사용하게 될 것이다. 그러나 여기서의 문제점은 인간이 사용하는 언어가 많은 경우에 애매 모호하다는 것이다.예를 들어 '키큰'혹은 '젊은'과 같은 주관적 느낌을 표현하는 단어를 기존의 컴퓨터 시스템에서는 처리할 수없어,오히려 '25세이상'과 같이 정확한 조건을 명시해야만 원하는 정보를 얻을수 있다.본 연구에서는 이와 같은 fuzzy 정보를 포함하는 문장을 처리할수 있는 지식 기반형 자연어 질의 응답 시스템 개발을 목표로 블랙보드 개념을 도입하고 있다.이러한 시스템을 개발하려는 목표는 임의의 데이타베이스 시스템 및 음성 이해 시스템을 연결사용이 가능한 portable질의 응답 시스템을 개발하려는데 있다.

• 의학교육논단
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• 제15권3호
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• pp.144-150
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• 2013

Before Outcome-based curriculum reform, medical graduate school and medical schools of korea need to understand limit or threshold of outcome-based education's point of view. This article examines the multi-dimensional concept of competence suggested by Stoof and colleagues and discusses about implication for outcomebased education in medical education of Korea. Because Stoof and colleagues's five dimensions of competence reveal various concepts and educational methods of competence. Therefore, It is possible to use to identify the strengths and weaknesses of outcome-based education of Korea as a reference standard. Five dimensions of competence suggested by Stoof and colleagues is consist of 'personal vs. task characteristics,' 'individual vs. distributed competence,' 'specific vs. general competence,' 'levels of competence vs. competence as a level,' and 'teachable vs. non-teachable.' Implication for outcome-based education in medical education of Korea is, first, that It should recognize to outcome-based education as a one of educational models approaching to competence. Second, discussion about competence should be expanded from pre-medical education to graduated medical education and continuing medical education.

• 한국콘텐츠학회논문지
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• 제3권4호
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• pp.55-62
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• 2003

본 논문에서는 무선망에서 핸드오프 호의 분실확률을 줄일 수 있는 호 제어 기법을 제안한다. 제안한 기법은 진행 중인 시스템 용량인 유효로드와 임계치를 이용하여 호의 수락 여부를 결정하며 측정된 유효로드가 미리 정해진 임계치보다 크면 신규 호는 차단시키고, 핸드오프 호는 큐잉을 허용한다. 호 수락 제어 기법의 성능분석을 위하여 추계적 페트리 네트의 확장인 SRN 모델이 개발된다. SRN 모델링 기법은 성능분석을 위하여 필요한 마르코프 체인의 복잡한 해석적 분석대신 보상 개념에 의한 손쉬운 성능분석 수행방법을 보여준다.

• 간호행정학회지
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• 제19권3호
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• pp.414-426
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• 2013

Purpose: The purpose of this study was to identify the process of overcoming the intention toward turnover experienced by career nurses. Methods: Data were collected from 10 career nurses though in-depth interviews about their experiences. The main question was "How do you describe your experience of the process of overcoming intention to turnover as a career nurse?" Qualitative data from field and transcribed notes were analyzed using Strauss & Corbin's grounded theory methodology. Results: From the participants' statement, 127 concepts, 34 subcategories and 13 categories were extracted through the open coding process. The core category was discovered to be 'back to the original place'. Phenomenon was identified as 'reached the threshold that cannot be withstood' and this series of process was categorized as having four stages: 'conflict', 'meditation', 'discovery' and 'conquest'. There were three types of overcoming turnover intention in career nurses, 'adjustment', 'compromise', 'self-led'. Conclusion: The results of this study produced useful information about the needs of career nurses during the process of overcoming turnover intention based on their stage and overcoming types of turnover intension. Ultimately this study may help decrease the turnover intention of career nurses.