• 한국안전학회지
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• 제12권3호
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• pp.67-75
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• 1997

This paper presents a study on the application of Asynchronous Team(A-Team) theory for QVC(Reactive power control) and security assessment in a power system. Reactive power control problem is the one of optimally establishing voltage level given reactive power sources, which is very important problem to supply the demand without interruption and needs methods to alleviate a bus voltage limit violation more quickly. It can be formulated as a mixed-integer linear programming(MILP) problem without deteriorating of solution accuracy to a certain extent. The security assessment is to estimate the relative robustness of the system and deterministic approach based on AC load flow calculations is adopted to assess it, especially voltage security. A distance measure, as a measurement for voltage security, is introduced. In order to analyze the above two problem, reactive power control and static security assessment, In an integrated fashion, a new organizational structure, called an A-team, is adopted. An A-team is well-suited to the development of computer-based, multi-agent systems for operation of large-scaled power systems. In order to verify the usefulness of the suggested scheme herein, modified IEEE 30 bus system is employed as a sample system. The results of a case study are also presented.

• 산경연구논집
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• 제11권11호
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• pp.19-28
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• 2020

Purpose: The supply of and demand for medical services continue to increase as the current social environment changes. Consequently, competition among medical institutions is intensifying and hospitals must establish appropriate management strategies to improve the medical services they provide. This study suggests that the authenticity of doctors is a factor in improving medical-service quality and examines the effect authenticity has on the affective trust and satisfaction of patients. Design, methodology, and approach: The study utilized previous studies to examine the significance of potential variables, established hypotheses and used a questionnaire to confirm these hypotheses. The questionnaire was distributed to patients who had visited a hospital in the previous six months. Responses were analyzed empirically using structural equation modeling. Findings: The analysis found that a physician's authenticity has a significant impact on the affective trust of patients. While patients' affective trust does not have a similar strong impact on patient satisfaction, physician authenticity does have a significant impact on patient satisfaction. Conclusion and implications: This study examined the roles of authenticity, affective trust, and patient satisfaction in doctor-patient relationships in the medical services field. The implication of the findings is that physician authenticity is a prerequisite for patient satisfaction of medical services.

• 한국환경과학회지
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• 제22권8호
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• pp.965-977
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• 2013

Reliable long-term streamflow forecasting is invaluable for water resource planning and management which allocates water supply according to the demand of water users. It is necessary to get probabilistic forecasts to establish risk-based reservoir operation policies. Probabilistic forecasts may be useful for the users who assess and manage risks according to decision-making responding forecasting results. Probabilistic forecasting of seasonal inflow to Andong dam is performed and assessed using selected predictors from sea surface temperature and 500 hPa geopotential height data. Categorical probability forecast by Piechota's method and logistic regression analysis, and probability forecast by conditional probability density function are used to forecast seasonal inflow. Kernel density function is used in categorical probability forecast by Piechota's method and probability forecast by conditional probability density function. The results of categorical probability forecasts are assessed by Brier skill score. The assessment reveals that the categorical probability forecasts are better than the reference forecasts. The results of forecasts using conditional probability density function are assessed by qualitative approach and transformed categorical probability forecasts. The assessment of the forecasts which are transformed to categorical probability forecasts shows that the results of the forecasts by conditional probability density function are much better than those of the forecasts by Piechota's method and logistic regression analysis except for winter season data.

• 한국게임학회 논문지
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• 제10권4호
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• pp.91-101
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• 2010

본 연구의 목적은 게임을 활용한 학습이 교육현장에서 교수-학습을 지원하는 방법으로 활용되기 위해 교사들의 인식을 조사하여 분석하는데 있다. 이는 게임기반학습의 확산을 위한 중요한 지표로 활용할 수 있을 것이다. 본 연구의 결과를 종합해보면, 첫째, 교사들이 게임을 사용하는데 있어 교육과정과 관련된 학습주제와 내용을 지닌 게임을 찾는데 어려움이 있다는 것이다. 둘째, 학습자의 다양한 수준에 따른 게임 활용 수업을 준비하는데 많은 시간이 소요된다는 것이다. 셋째, 교사가 게임을 수업에 활용하기 위해 관련기관에서 다양한 정보와 지침을 제공해야할 필요가 있다는 것이다. 마지막으로, 행-재정적인 지원이 체계적으로 이루어져야할 필요가 있는 것으로 나타났다.

• 한국콘텐츠학회:학술대회논문집
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• 한국콘텐츠학회 2005년도 추계 종합학술대회 논문집
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• pp.590-595
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• 2005

RFID(Radio Frequency Identification)는 효율적이고 정확하게, 제품을 인식하는 새로운 수단으로 대두되고 있다. RFID 기술사용은 산업분야의 초과 재고조사, 위조품, 노동 비용을 감소시키고 공급망을 향상시킬 수 있을 것이다. RFID 기술은 제품을 인식하기 위해 RF를 사용한다. 각 제품에는 EPC(Electronic Product Code)라는 작은 태그가 부착되어 있으며, 특정 상품 정보를 포함하고 있다. 각각의 EPC는 유일하며 개개의 제품을 인식할 수 있다. EPC 태그가 특정 위치로 이동하게 되면 리더는 태그를 읽게 되며, 태그 데이터는 데이터 저장 시스템인 EPC 정보서비스에 저장된다. 모든 서비스가 웹 서비스를 통하여 EPC 정보서비스로 접근될 수 있으며, 사용자가 서비스를 요구할 때 마다 사용자에게 원하는 데이터를 제공해 준다. 본 연구에서는 EPC 정보서비스를 이용하여 재고관리 시스템을 구현해 보았다.

• Nuclear Engineering and Technology
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• 제39권5호
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• pp.655-662
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• 2007

Most decision makers in the electricity industry plan their electric power expansion program by considering only a least cost operation, even when circumstances change with differing complexities. It is necessary, however, to analyze a long-term power expansion plan from various points of view, such as environmental friendliness, benefit of a carbon reduction, and system reliability, as well as least cost operation. The objective and approach of this study is to analyze the proper role of nuclear power in a long-term expansion plan by comparing different scenarios in terms of the system cost changes, $CO_2$ emission reduction, and system reliability in relation to the Business-As-Usual (BAU). The conclusion of this paper makes it clear that the Korean government cannot but expand the nationwide nuclear power program, because an increased energy demand is inevitable and other energy resources will not provide an adequate solution from an economic and sustainability point of view. The results of this analysis will help the Korean government in its long-term resource planning of what kinds of role each electric resource can play in terms of a triangular dilemma involving economics, environmental friendliness, and a stable supply of electricity.

• 한국건설관리학회:학술대회논문집
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• 한국건설관리학회 2008년도 정기학술발표대회 논문집
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• pp.371-375
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• 2008

최근 우리나라 주택 시장은 잦은 정책 변화 등 내부적 요소와 해외 경제 환경 변화 등 외부적 요소에 의해 예측할 수 없는 상황이 계속되고 있다. 특히 미래 주택 시장에 대한 가격, 수요, 공급을 예측하는 데에 있어 어려움을 겪고 있다. 이에 따라 주택 시장 변화에 대한 다양한 분석이 이루어지고 있으나 부분적이고 단편적인 시각이 주를 이루고 있어, 인과관계에 따른 주택시장을 분석할 수 있는 시스템적 논리의 필요성이 대두되고 있다. 따라서 본 연구에서는 주택의 수요와 공급에 의해 결정되는 주택시장의 기본 원리를 바탕으로 시스템 다이내믹스(System Dynamics)를 이용한 주택 시장 작동 원리를 작성하여, 내 외부 환경변화에 따른 주택 시장의 영향을 파악할 수 있는 기본 모형을 구축하고자 한다.

• 한국건축시공학회지
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• 제8권5호
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• pp.67-73
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• 2008

Recent trends in construction towards larger scale and taller buildings are causing problems by ineffective existing management approach in construction industry have emerged. Delivering necessary materials and mobilizing the human resources and equipment In a timely manner to keep labor on schedule have become a critical issue to be addressed. In particular, many specialty contractors carrying out multiple projects have been experiencing difficulties mobilizing the manpower on time and in right places due to poor communication at each stage of labor supply, resulting in waste of valuable resources. Hence, it's imperative for the specialty contractors to obtain specific information on labor demand so as to set up a communication and labor management system to ensure the right human resources will be mobilized in the right place at the right time. The study therefore is aimed at developing an optimal human resources management system for specialty contractors performing multiple projects. To that end, the study is focused on rebar and concrete work. The outcome of the study is expected to help allocate the right human resources to the right place in a timely fashion, thereby achieving an effective workflow at construction sites.

• Industrial Engineering and Management Systems
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• 제9권2호
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• pp.97-106
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• 2010

Can eBay.com's fee structure coordinate the channel? It's a critical strategic problem in e-commerce operations and an interesting research hypothesis as well. eBay's fees include three parts: monthly subscription fee, insertion fee, and final value fee (i.e., a revenue sharing portion), which represent a generic form of revenue sharing fee structure between the retailer and the vendor in a supply chain. This research deals with such a channel consisting of a price-setting vendor who sells products through eBay's marketplace exclusively to the end customers. The up- and down-stream channel relationship is consignment-based revenue sharing. We use a game-theoretic approach with assumption of the retailer (i.e., eBay.com) being a Stackelberg-leader and the vendor being a follower. The Stackelberg-leader decides on the terms of revenue sharing contract (i.e., fee structure), and the follower (vendor) decides on how many units to sell and the items' selling price. This study formulates several profit-maximization models by considering the effects of the retail price on the demand function. Under such settings, we show that eBay's fee structure can improve the channel efficiency; yet it cannot coordinate the channel optimally.

• 사회경제평론
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• 제31권2호
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• pp.1-38
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• 2018

본 연구에서는 한국경제에 수출이 얼마만큼 영향력을 미치고 있는지, 그리고 과거에 비하여 영향력의 크기에 어떤 변화가 있는지에 대하여 정량적으로 분석한다. 이를 위해 첫째, 한국경제에서 수출승수 효과의 크기를 추정하고, 수출승수 효과가 2008년 금융위기 이후 감소하였음을 보이고자 한다. 둘째, 한계소비성향의 감소가 수출승수 감소의 주요 요인으로 작용하였을 가능성에 대하여 논해보고자 한다. 마지막으로, 이러한 분석을 통하여 향후 한국경제의 지속적인 성장을 위해 수출정책의 방향과 한계점에 대한 대응방안 등의 시사점을 제공하고자 한다.