• Journal of the Korea Society for Simulation
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• v.29 no.4
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• pp.47-54
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• 2020

North Korea has recently developed and deployed missiles with various ranges as asymmetrical forces. Among them, short-range ballistic missiles with improved accuracy are expected to aim at achieving tactical goals by hitting important military facilities in Korea with a small number of missiles. Damage to the air force airfields, one of North Korea's main targets of missiles attack, could limit the operation of air force fighters essential to gaining air superiority. Based on the attack by the short range ballistic missiles, the damage probability of military airfields was simulated. And as the one of the concepts of passive defense, the way to reduce the loss of combat power was studied through the changes of the air force squadrons deployment. As a result, the effective deployment plan could be obtained to reduce the amount of power loss compared to the current deployment.

• Journal of The Korean Association For Science Education
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• v.36 no.1
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• pp.147-158
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• 2016

This study examined the changes of preservice biology teachers' NOS pedagogical content knowledge through two consecutive science methods courses: NOS understandings; attitudes toward teaching science; difficulties of NOS teaching; NOS teaching strategies; and views of orientation of NOS teaching. During the science methods course I, the preservice teachers engaged in discussions and reflections on what science is and how scientific knowledge has produced, drawing NOS aspects from episodes of history of science, and planning the lessons cooperating NOS instructional objectives. Then the next semester, through the science methods course II, the preservice teachers had a chance of the simulated teaching by adopting NOS teaching and learning activities in the context of the secondary biology context. The preservice teachers, further, reflected on their NOS teaching. The results showed that the preservice teachers constructed the NOS pedagogical content knowledge. They significantly improved their views of NOS and its teaching(p<.05) after the science methods course I, and retained their understanding after the science methods course II(p>.05). The preservice teachers mentioned the difficulties of teaching NOS in the secondary biology context, and further suggested effective NOS teaching methods in their reflective journals.

• Journal of the Korean Society of Hazard Mitigation
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• v.10 no.1
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• pp.89-102
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• 2010

Future uncertainty on water demand caused by future climate condition and water consumption leads a difficulty to determine the reservoir operation rule for supplying sufficient water to users. It is, thus, important to operate reservoirs not only for distributing enough water to users using the limited water resources but also for preventing floods and drought under the unknown future condition. In this study, the reservoir storage is determined in the first stage when future condition is unknown, and then, water distribution to users and river stream is optimized using the available water resources from the first stage decision using 2-stage stochastic linear programming (2-SLP). The objective function is to minimize the difference between target and actual water storage in reservoirs and the water shortage in users and river stream. Hedging rule defined by a precaution against severe drought by restricting outflow when reservoir storage decreases below a target, is also applied in the reservoir operation rule for improving the model applicability to the real system. The developed model is applied in a system with five reservoirs in the Han River basin, Korea to optimize the multi-reservoir system under various future water demand scenarios. Three multi-purposed dams - Chungju, Hoengseong, and Soyanggang - are considered in the model. Gwangdong and Hwacheon dams are also considered in the system due to the large capacity of the reservoirs, but they are primarily for water supply and power generation, respectively. As a result, the water demand of users and river stream are satisfied in most cases. The reservoirs are operated successfully to store enough water during the wet season for preparing the coming drought and also for reducing downstream flood risk. The developed model can provide an effective guideline of multi-reservoir operation rules in the basin.

• Journal of Environmental Impact Assessment
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• v.26 no.6
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• pp.479-494
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• 2017

After Fukushima incident, negative sentiment towards nuclear power has led to transition in policies that reduce the dependency on nuclear power in some countries. President Moon of Republic of Korea also announced a national plan of decommissioning retired nuclear power plants stage by stage. Therefore, nuclear power that once was considered the critical solution to energy security and climate change is now a limited option. This study aims to find an optimal energy mix in Korea's electricity system from 2016 through 2030 to combat climate change through energy transition with minimum cost. The study is divided into two different scenarios; energy transition and nuclear sustenance, to compare the total costs of the systems. Both scenarios show that electricity generated by wind technology increases from 2018 whereas that of photovoltaic(PV) increases from 2021. However, the total cost of the energy transition scenario was USD 4.7 billion more expensive than the nuclear sustenance scenario.

• Journal of the Korean Institute of Landscape Architecture
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• v.49 no.3
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• pp.11-28
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• 2021

Due to its size and complex characteristics, it is not often to newly create a large park within an existing urban area. Also, there has been a lack of research on the planting design methodologies for a large park. This study aims to elucidate how ecological ideas can be applied to planting practice from a designer's perspective, and eventually suggest a planting design framework in the actual case, the Central Park in the City of Gwangju. This framework consists of spatial structure of planting area in order to connect and unite the separated green patches, to adapt to the changes of existing vegetation patterns, to maintain the visual continuity of landscape, and to organize the whole open space system. The framework can be provided for the spatial planning and planting design phase in which the landscape designer flexibly uses it with the design intentions as well as with an understanding of the physical, social, and aesthetic characteristics of the site. The significance of this approach is, first that it can maintain ecological and visual consistency of the both existing and introduced landscapes as a whole in spite of its intrinsic complexity and largeness, and second that it can help efficiently respond to the unexpected changes in the landscape. In the case study, comprehensive site analysis is conducted before developing the framework. In particular, wetlands and grasslands have been identified as potential wildlife habitat which critically determines the vegetation patterns of the green area. Accordingly, the lists of plant communities are presented along with the planting scheme for their shape, layout, and relations. The model of the plant community is developed responding to the structure of surrounding natural landscape. However, it is not designed to evolve to a specific plant community, but is rather a conceptual model of ecological potentials. Therefore, the application of the model has great flexibility by using other plant communities as an alternative as long as the characteristics of the communities are appropriate to the physical conditions. Even though this research provides valuable implications for landscape planning and design in the similar circumstances, there are several limitations to be overcome in the further research. First, there needs to be more sufficient field surveys on the wildlife habitats, which would help generate a more concrete planting model. Second, a landscape management plan should be included considering the condition of existing forest, in particular the afforested landscapes. Last, there is a lack of quantitative data for the models of some plant communities.

• Journal of Korean Neurosurgical Society
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• v.29 no.9
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• pp.1228-1232
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• 2000

Objective : This study was undertaken to analysis gamma knife radiosurgery(GKR) effect for trigeminal neuralgia after long term follow-up. Methods : There were 11 trigeminal neuralgia patients. The authors irradiated 67-85 Gy maximally to the nerve root entry zone(NREZ) using single 4mm collimator, just 1-6mm lateral side from the junction of the trigeminal nerve and pons. For the first 3 cases, we targeted the junction between the nerve and the pons. In theses cases, the pons was irradiated 56 or 60 gray in the surface. In the later 8 cases, the isocenter is positioned more distal side so that the brain stem surface would receive less than the 20% isodose. Results : The average follow-up duration was 25 months(13-50 months). Pain relief was noticed within a week to 5 months. In 3 patients, pain was relieved completely and in other 3 patients, mark improvement was achieved(80-90%). Remaining 4 patients showed significant improvement(30-50%). There was recurrence in only one case and she complained with similar intensity of pain at the last follow-up. There was no significant complication related to GKR. Conclusion : GKR is considered effective for trigeminal neuralgia based on the long term follow-up evaluation, but more clinical experience is needed to evaluate the efficacy of GKR for trigeminal neuralgia as a primary treatment modality.

• Proceedings of the Korean Society for Quality Management Conference
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• 2007.04a
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• pp.334-339
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• 2007

인터넷은, 전화로 대변되는 과거의 정보통신 서비스와는 달리 사회 전반에 막대한 영향력을 행사하는 서비스로 발전하였다. 인터넷에 대한 의존도는 향후 모든 정보통신서비스가 인터넷을 기반으로 제공되는 All-IP 디지털 컨버전스 시대에 더욱 더 심화될 것이다. 이 경우 오늘날의 인터넷보다도 QoS(Quality of Service)에 관한 이슈가 더욱 중요해질 것은 자명하다. 이러한 배경에서 ITU(International Telecommunication Union)나 IETF(Internet Engineering Task Force)등의 국제표준화 기구에서 차세대 인터넷 (Next Generation Network, NGN)에 대한 QoS 문제를 연구하고 있다. 그러나 이들 국제기구는 주로 기술공학적인 측면에서 QoS 문제에 접근하고 있어서 현실적으로 완전한 대안을 제공하지는 못하고 있다. 즉, 인터넷 산업의 특성상 사업자간 끊김없는 연동(seamless inter-operations)과 협력이 필수적인데, 이는 기술공학적 측면보다도 비즈니스 및 정책적 관점에서 다루어져야 되기 때문이다. 통신 사업자 및 벤더(vendor)의 글로벌 컨소시엄으로 출발한 TMF(TeleManagement Forum)나 QuEST Forum 등의 역할이 중요해지는 이유가 여기에 있다. 이미 이들 단체는 사업자간 합의에 의해 자발적으로 구축한 NGOSS 및 TL9000 인증시스템을 바탕으로, 망사업자를 비롯한 서비스공급자 및 벤더 등과의 원활한 협력관계를 구축하는 글로벌 de facto 표준을 마련한 바 있다. 본 연구에서는 QoS 보장을 목표로 하는 차세대 인터넷(NGN)의 현실적 성공 가능성을 높이기 위한 글로벌 표준화 노력을 소개하고 이들을 비교/검토한다. 특히, ITU 및 IETF 등의 NGN 개발계획을 비즈니스/정책점 관점에서 보완할 수 있는 TMF와 QuEST Forum의 접근법을 고찰하여, All-IP 컨버전스 환경에서의 QoS 이슈에 시사하는 바를 살펴본다.

• Journal of Korea Water Resources Association
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• v.30 no.3
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• pp.257-268
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• 1997

Reservoir operators and managers need to present a rational basis of determining releases for a flood event. This study divides a forecasted flood hydrograph by two parts on the basis of non-damaging discharge, which consists of one part con,trolled by non-damaging discharge and another controlled by using flood control storage of the reservoir. In case of using flood control storage, a new reservoir operation method. called TRF (Transformed Reservoir Flood) ROM, is suggested for the operating rules during a flood to consider the reservoir security as well as the operational efficiency. This paper presents an application of the methodology to the operation of a single multipurpose reservoir at the Taechong Dam during flood and the results analyzed.alyzed.

• Proceedings of the Korea Water Resources Association Conference
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• 2011.05a
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• pp.223-227
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• 2011

유역 특히 상습침수지구의 통합관리는 유역이라는 한정된 범위 내에서 물에 영향을 미치거나 물에 의하여 영향을 받는 모든 인간 활동과 자연현상을 통합적으로 고려하는 것이다. 이러한 관점에서 유역관리는 유역 차원에서 물을 경제적이고 공평하게 관리하고 분배하여 수자원에 대한 장기적이고 지속가능한 해결방안을 마련하는 것이다. 여기에는 정부, 시민사회 및 기업 행위자가 사회경제적 개발목표와 정책형성, 집행계획을 수립하는 것으로부터 시작된다. 유역관리를 위한 의사결정들은 행위자들과의 영향으로 수정되며, 이런 과정에서 토지와 수자원에서 분쟁이 발생하며, 수자원 관리자는 자연현상, 물 사용, 재정적, 인적자원 및 외부적인 요인으로 인해 목적을 달성하는데 부합하지 않을 수도 있다. 효과적인 유역관리를 위해서는 제약조건하에서 수자원 관리자가 의사결정에 정보를 주고 주요 행위자들과 협력을 통해서 이루어 질 수 있다. 본 논문에서는 유역관리를 위한 의사결정을 행위자기반모형(Agent based Model, ABM)으로 이해하고자 하며, ABM은 유역관리의 이해당사자간의 정책과정을 도출하고 다양한 유역관리 대안을 평가하고 유역관리의 영향을 설명하는 모델이다. 본 모형은 관측자료를 통해 상향식 접근법으로 가능한 많은 세부사항을 모의할 수 있다. 분석과정은 자료의 수집, 모델 확립, 모델의 개발, 통계자료 수집 및 모델의 결과와 실제 시스템의 보충된 관측자료를 비교하는 검증 순으로 진행되며, 본 모델에서의 행위자는 과거의 행동으로부터 주위 환경의 반응하는 패턴을 확인하고 개발하며, 이러한 패턴은 정책들을 구별하기 위해서 이용되며, 이러한 과정에서 강화학습이 이루어진다. 이를 통해 행위자의 익숙한 방식의 합리적인 행동과 정책들의 상관관계를 평가할 수 있으며, 강화학습을 통해 실제적인 통계적인 모델이 가능하다.

• Korean Business Review
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• v.17 no.2
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• pp.185-202
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• 2004

There is an increasing interest in measuring and comparing the efficiency of organization units whose operations are functionally similar and autonomous. Data Envelopment Analysis(DEA) has been extensively used to evaluate the efficiency of non-profit organizations as a whole. This study applies a modified DEA model (Input-oriented BCC model with Nondiscretionary variables) to identify the performance of local government in Korea. It is found that utilizing DEA as a mean of evaluating the performance of local governments yields useful information to decision makers trying to maintain more efficient practices.