• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2007년도 춘계종합학술대회
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• pp.657-660
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• 2007

정보화의 진전에 따라 교육은 동일한 지식의 일방적 전달인 전통적인 교육에서 시 공간을 초월하여 학습자-내용간, 학습자-교수자간, 학습자-학습자간 다차원적으로 학습자 스스로가 자기 주도적으로 학습을 하는 양방향 교육 및 수요자 중심의 평생교육으로 전환되고 있다. 이러한 시대적 조류에 맞추어 학습자의 요구에 부응하는 교육방법론이 필요하다. 따라서 본 논문에서는 학습자 주도의 상호 작용을 극대화할 수 있는 학습자 중심의 WBI를 활용한 실시간 원격교육 시스템을 제안한다. 학습자가 스스로 학습을 설계하고 계획하여 다양한 상호작용을 통하여 자기주도적으로 학습에 참여할 수 있는 개별학습과 학습자들의 건전한 토론과 대화의 장을 마련하여 모둠원들 간의 집단별 프로젝트 학습을 할 수 있도록 하였다.

• Nuclear Engineering and Technology
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• 제53권10호
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• pp.3236-3246
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• 2021

Lessons learned from the Fukushima Daiichi nuclear power plant accident directed that multiple failures should be considered more seriously rather than single failure in the licensing bases and safety cases because attempts to take accident management measures could be unsuccessful under the high radiation environment aggravated by multiple failures, such as complete loss of electric power, uncontrollable loss of coolant inventory, failure of essential safety function recovery. In the case of the complete loss of electric power called station blackout (SBO), if there is no mitigation action for recovering safety functions, the reactor core would be overheated, and severe fuel damage could be anticipated due to the failure of the active heat sink. In such a transient condition at CANDU-6 plants, the seal failure of the primary heat transport (PHT) pumps can facilitate a consequent increase in the fuel sheath temperature and eventually lead to degradation of the fuel integrity. Therefore, it is necessary to specify the regulatory guidelines for multiple failures on a licensing basis so that licensees should prepare the accident management measures to prevent or mitigate accident conditions. In order to explore the efficiency of implementing accident management strategies for CANDU-6 plants, this study proposed a realistic accident analysis approach on the SBO transient with multiple-failure sequences such as seal failure of PHT pumps without operator's recovery actions. In this regard, a comparative study for two PHT pump seal failure modes with and without coolant seal leakage was conducted using a best-estimate code to precisely investigate the behaviors of thermal-hydraulic parameters during transient conditions. Moreover, a sensitivity analysis for different PHT pump seal leakage rates was also carried out to examine the effect of leakage rate on the system responses. This study is expected to provide the technical bases to the accident management strategy for unmitigated transient conditions with multiple failures.

• 한국산학기술학회논문지
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• 제19권3호
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• pp.260-266
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• 2018

고객의 기술 채택에 영향을 미치는 고객효용도의 개념에 대한 이해는 다세대 기술의 확산 및 대체 과정을 이해하는데 중요하다. 본 연구에서는 다세대 기술의 속성 기반 고객효용도의 개념에 대해 정의하고, 고객효용도를 측정할 수 있는 모형을 개발하였다. 문헌리뷰 및 모형화를 바탕으로 다세대 기술의 속성 기반 고객효용도에 대해 정의 및 측정 모형을 제시하였고, 도출한 모형의 정합성을 반도체 산업 사례를 바탕으로 검증하였다. 다세대 기술에서 속성 기반 고객효용도는 세대별로 또는 같은 세대 내에서 시간별 변화를 고려해야하고, 기술적 속성과 경제적 속성에 대해 가중치를 고려한 모든 효용도들의 합으로 정의된다. 또한 속성 기반 고객효용도는 효용도 변환표를 통해 속성들의 값을 효용도로 전환한 후 가중치를 고려한 모든 속성들의 효용도의 합으로 모형화 가능하다. 본 연구를 통해 다세대 기술이 확산 및 대체되는 과정에서 고객의 기술 채택의 근본 동인으로서 영향을 미치는 고객효용도에 대해 이해 가능하고, 고객효용도를 바탕으로 확산 및 대체 경로를 예측하여 기술전략을 수립하는데 유용할 것이다.

• 한국항공우주학회지
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• 제43권6호
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• pp.488-496
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• 2015

본 연구에서는 각각 다른 목적지에서 다수의 임무를 수행해야하는 복수 무인항공기(Unmanned Aerial Vehicle, UAVs)의 경로를 결정할 때, 무인항공기의 생존가능성을 고려하여 경로를 결정하는 프레임워크를 제안하였다. 본 라우팅 문제는 무인항공기 안전과 임무 완료시간 간의 trade-off 를 나타내는 비용 매트릭스를 이용한 차량경로문제(Vehicle Routing Problem, VRP)로 정의할 수 있다. 특정위치에서 무인항공기의 위험 레벨은 감지될 확률과 격추될 확률을 고려하여 모델링 하였고, 위협 레벨과 비행거리를 고려한 두 지역간의 최소비용경로는 육각형격자(Hexagonal cells)에서 Dijkstra 알고리듬을 사용하여 결정하였다. 또한, 지속적으로 다수의 적을 감시 정찰하는 임무를 수행하는 복수 무인항공기의 최적경로를 결정하는 case study를 수행하였으며, 그 결과를 논의하였다.

• Journal of Preventive Medicine and Public Health
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• 제54권4호
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• pp.238-244
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• 2021

Objectives: Previous pandemics have demonstrated that several demographic, geographic, and socioeconomic factors may play a role in increased infection risk. During this current coronavirus disease 2019 (COVID-19) pandemic, our aim was to examine the association of timing of lockdown at the county level and aforementioned risk factors with daily case rate (DCR) in the United States. Methods: A cross-sectional study using publicly available data was performed including Americans with COVID-19 infection as of May 24, 2020. The United States counties with >100 000 population and >50 cases per 100 000 people were included. The independent variable was the days required from the declaration of lockdown to reach the target case rate (50/100 000 cases) while the dependent (outcome) variable was the DCR per 100 000 on the day of statistical calculation (May 24, 2020) after adjusting for multiple confounding socio-demographic, geographic, and health-related factors. Each independent factor was correlated with outcome variables and assessed for collinearity with each other. Subsequently, all factors with significant association to the outcome variable were included in multiple linear regression models using stepwise method. Models with best R² value from the multiple regression were chosen. Results: The timing of mandated lockdown order had the most significant association on the DCR per 100 000 after adjusting for multiple socio-demographic, geographic and health-related factors. Additional factors with significant association with increased DCR include rate of uninsured and unemployment. Conclusions: The timing of lockdown order was significantly associated with the spread of COVID-19 at the county level in the United States.

• 유통과학연구
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• 제20권1호
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• pp.109-114
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• 2022

Purpose: The purpose of this study is to confirm that multichannel distribution strategies may be used for cultural and artistic products such as musicals, just as for general consumer goods, through a case study on the distribution strategy for a musical title. In addition, a distribution strategy for cultural and artistic products is proposed based on the analysis of the case. Research design, data, and methodology: Qualitative research methods, such as case study research and in-depth interviews, were used in this study. Results: The case study of the Korean musical Myeongdong Romance confirmed that multichannel distribution strategies may be used for musicals, including performances at theaters, Naver TV screenings (a service linked to an Internet portal), LGU+ screenings (an IPTV and OTT media service), DVD releases, and screenings of recordings of Romance Hall performances. Conclusion: For cultural and artistic products such as musicals, distribution channels can be diversified to incorporate the simultaneous use of multiple channels. New cases involving other cultural and artistic products and services to which this distribution strategy is applicable may be identified, and the strategy may be implemented along with new technologies to reduce costs further.

• Journal of Korean Neurosurgical Society
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• 제38권1호
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• pp.16-22
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• 2005

Objective : The authors characterize a syndrome of multiple neurogenic tumors in the spinal canal, which is unclassifiable by the current National Institute of Health[NIH] criteria for neurofibromatosis. Methods : We retrospectively examined cases in which two or more spinal neurogenic tumors were detected by magnetic resonance[MR] imaging and which had been pathologically confirmed. Eighteen patients were recruited between February 1986 and March 2002. According to NIH criteria, eight cases were neurofibromatosis type 1[NF1], four were type 2[NF2], and six were neither type 1 nor type 2 [Unclassifiable : UC]. The locations of lesions, clinical presentations, radiological findings, and pathological results with immunohistochemistry were reviewed. Results : In the case of NF2, three of four cases were intradural tumors. Pathological examinations revealed neurilemmomas in two of four NF2 and all of the UC cases. In the case of NF1, pathological examinations showed seven neurofibromas and one neurilemmoma. Concerning UC, the age at presentation was middle-aged to late [mean age 48.5, range 35 to 64], which contrasted with ordinary NF2, where patients tended to become symptomatic before 20years of age. The pathological examinations of UC cases revealed neurilemmoma similar to most of NF2 and the immunohistochemical study showed characteristic of NF1. Conclusion : Multiple neurogenic tumors in the spinal canal are an under-recognized disease entity. Further studies for genetic aberration in multiple spinal neurogenic tumors are needed.

• Journal of Astronomy and Space Sciences
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• 제29권1호
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• pp.11-21
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• 2012

In this paper, the authors introduced a new approach to find the optimal collision avoidance maneuver considering multi threatening objects within short period, while satisfying constraints on the fuel limit and the acceptable collision probability. A preliminary effort in applying a genetic algorithm (GA) to those kinds of problems has also been demonstrated through a simulation study with a simple case problem and various fitness functions. And then, GA is applied to the complex case problem including multi-threatening objects. Two distinct collision avoidance maneuvers are dealt with: the first is in-track direction of collision avoidance maneuver. The second considers radial, in-track, cross-track direction maneuver. The results show that the first case violates the collision probability threshold, while the second case does not violate the threshold with satisfaction of all conditions. Various factors for analyzing and planning the optimal collision avoidance maneuver are also presented.

• 대한산업공학회지
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• 제39권6호
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• pp.517-534
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• 2013

In this study, we propose the guideline with strategic model for new product development. To establish the guideline, 1) we classify several types of successful surveyed cases that achieved open innovation through applying crowdsourcing into new product development environment, 2) draw case maps using two or three axis with characteristics such as: step of product development process, crowdsourcing frequency, and product type of each case, 3) define the type of applying crowdsourcing into new product development environment based on case analysis results, and tabulate a crowdsourcing type based on the defined crowdsourcing type, 4) finally, suggest the guideline with multiple points of view which embrace type of crowd, community management, participation method, knowledge adoption method, and reward policy. Using the suggested guideline will help a company to design and establish open innovation in new business model related to product development area.

• 한국전자거래학회:학술대회논문집
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• 한국전자거래학회 2000년도 종합학술대회발표논문집
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• pp.207-214
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• 2000

Over the last several decades, the topic of the source selection and evaluation has gained a great attention in the information systems community as an effective tool to acquire information systems in an organization. The source selection and evaluation process is a multiple-criteria decision-making problem associated with several evaluation issues. In this case study, evaluation issues include management, technologies, logistics, and cost. This case study was conducted to compare a new source selection and evaluation process by using the analytic hierarchy process with the traditional approach. This study provides useful insight about how to apply the analytic hierarchy process technique to the traditional approach.