• Proceedings of the Korean Nuclear Society Conference
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• 1996.05a
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• pp.349-354
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• 1996

SACOM(Simulation Analyser with Cognitive Operator Model) is being developed at Korea Atomic Energy Research Institute to simulate human operator's cognitive characteristics during the emergency situations of nuclear power plans. An operator model with error mechanisms has been developed and combined into SACOM to simulate human operator's cognitive information process based on the Rasmussen's decision ladder model. The operational logic for five different cognitive activities (Agents), operator's attentional control (Controller), short-term memory (Blackboard), and long-term memory (Knowledge Base) have been developed and implemented on blackboard architecture. A trial simulation with a scenario for emergency operation has been performed to verify the operational logic. It was found that the operator model with error mechanisms is suitable for the simulation of operator's cognitive behavior in emergency situation.

• Korean Chemical Engineering Research
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• v.58 no.4
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• pp.596-603
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• 2020

In this study, a mathematical model for optimal operation of the fusion fuel cycle is developed based on scheduling approach. The fusion fuel cycle consists of a system for storing and supplying deuterium and tritium, and receiving and separating process after the fusion reaction. Except that tritium is a radioactive material, most of these processes consist of catalytic reactions and separation process. For these reasons, it is possible to apply scheduling approach which is also widely utilized to chemical plants to derive the optimal operating scenarios. The developed model determined the optimal regeneration cycle to minimize the amount of tritium inside the vacuum pumps. Based on the characteristics of various device in the fusion reactor, the optimal tritium plant operation scenario is evaluated. The formulated model was applied to the actual tokamak scenario and utilized to analyze the fuel flow and balance of ITER fuel cycle.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.34 no.4
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• pp.1261-1267
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• 2014

It is generally recognize that the weight of energy cost for railroad alignment in the life cycle cost is higher than that for roadway. This study analyzed the relative weights of railroad road-bed construction cost and energy cost in the case of Seoul-Pusan High Speed Rail. Recently, the optimization of railroad alignment with computerized methodology has been studies. The optimization is supposed to aim the minimization of life cycle cost including the energy cost as well as the minimization of the construction cost. The operation period of the Seoul-Pusan High Speed Rail is limited to ten years, then various future operation scenario were developed for the next 20 years. The weight of energy cost is estimated 10~30% of the construction cost by scenario, and it is lower than the figure generally expected. It may be meaningful to provide the method to include the energy cost in the railroad alignment optimization.

• Journal of Digital Convergence
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• v.10 no.11
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• pp.197-202
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• 2012

Block Train Services(BTS) are actively studied in many countries for higher productivity and eco-friendly systems of inland freight distribution. However it is difficult for an ordinary student or researcher to approach for understanding and studying BTS because rail transport is operated monopolistically by Korea government and most freight information in each company belongs to its business secret due to the industrial characteristics. For such reasons, the study aimed to develop a BTS simulation model that it supports understanding and strategic decision required for BT operation. To build the result, expert depth-interviews were conducted with analysis of relative references through the domestic representative BT operating company K. The simulator refers to the Busan NewPort-Uiwang section and functionally, it supports scenario generation and analysis on BT operation. It makes a contribution to study a new type's technological application for learning and strategic analysis of BTS.

• Korean Journal of Agricultural Science
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• v.47 no.2
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• pp.337-347
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• 2020

Since 2012, despite the fact that tariff rate quotas (TRQ) in the form of dried peppers has not been imported, the imports of pepper-related items such as low- tariff frozen peppers (27%) and other sauces (45%) have increased, there has been a problem in the domestic pepper industry, in which the domestic self-sufficiency rate has declined. The purpose of this study was to find out whether the operation of chili pepper TRQ has the effect of suppressing the imports of pepper-related items from China. We analyzed the import substitution effect (import suppression effect) through causal analysis of the imports of red pepper TRQ, frozen peppers, and other sauces using the structural equation model analysis method. As a result of the hypothetical scenario analysis, when the government imports and releases 7,185 tons of pepper TRQ in 2019/20 (scenario), private imports were estimated to decrease by only 3,060 tons. In other words, the import substitution effect between imported items was estimated to decrease about 2,079 tons of private dried peppers, and about 981 tons of imported pepper-related items. There was an effect of suppressing the imports of pepper-related items such as frozen peppers, but it was analyzed to be insignificant. That reason was that the replacement substitution elasticity of the pepper-related items for TRQ import was less than 1 (inelastic). Therefore, it is judged that the government's operation of the pepper TRQ is preferably focused on stabilizing domestic prices rather than focusing on import control of pepper-related items.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.66 no.12
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• pp.1905-1912
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• 2017

In recent years, Ulaanbaatar, a capital of Mongolia has witnessed major problem that air quality reaches hazardous level during the winter season. Coal combustion for heating of every house in "Ger" district is main reason. One way to reduce the air pollution is mass usage of electric heater. However, there are several difficulties such as overload and degradation of transformers and other equipment used in distribution and transmission systems as well as power shortage occurrence in evening peak period due to residential consumption. This study aims to contribute for solving the air pollution and power shortage problem in Mongolia. One possible solution could be distributed generation (DG) with photovoltaic (PV) penetration. In this study, PV with energy storage (ES) hybrid system to reduce peak load is analyzed. We proposed the suitable structure of PV-ES hybrid for Mongolian household, and suggested several operation scenarios. Optimal operation algorithm is carried out based on a comparison aspect from economical, grid impact and PV penetration possibility. The economic analyse shows annual income of 520USD, and has a payback period of 8 years for selected scenario. The proposed PV-ES system structure is verified by experimentation set on the building rooftop in city center. The suggested scenario is planned to apply for system in further research.

• International Journal of Internet, Broadcasting and Communication
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• v.13 no.4
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• pp.103-111
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• 2021

In modern society, digital lifestyles are spreading to minimize contact with people and to receive contactless information. The spread trend has established an unmanned distribution system in which transactions through contactless technologies such as kiosks and chatbots are activated in face-to-face transactions with sellers and consumers. In order to streamline logistics supply worldwide, digital new deal based joint logistics hubs, unmanned courier storage platforms, and fresh logistics based last mile services have been developed into unmanned logistics systems, focusing on the intelligent logistics system automation process. Unmanned courier storage system installed in urban areas and home to daily logistics where volume is concentrated are provided with fresh logistics services through cold chain and receiving freights in contactless environments. Development is also underway to minimize safety accidents caused by courier services, such as managing various information based on the integrated control system. This paper defines the concept of integrated operation for the development of a platform for contactless unmanned courier storage device developed into next-generation logistics system. In addition, we intend to develop systems engineering-based output for deriving safety requirements and specifications by identifying risk sources that may occur in the operational scenario. Therefore, the goal is to establish a foundation for safety and reliability between interfaces of logistics systems to be installed in apartment and subway station environments that want to provide unmanned logistics services to various consumers.

• Nuclear Engineering and Technology
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• v.42 no.5
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• pp.582-589
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• 2010

As a part of the back-end fuel cycle, transportation of spent nuclear fuel (SNF) from nuclear power plants (NPPs) to a fuel storage facility is very important in establishing a nuclear fuel cycle. In Korea, the accumulated amount of SNF in the NPP pools is troublesome since the temporary storage facilities at these NPP pools are expected to be full of SNF within ten years. Therefore, Korea cannot help but plan for the construction of an interim storage facility to solve this problem in the near future. Especially, a decision on several factors, such as where the interim storage facility should be located, how many casks a transport ship can carry at a time and how many casks are initially required, affect the configuration of the transportation system. In order to analyze the various possible candidate scenarios, we assumed four cases for the interim storage facility location, three cases for the load capacity that a transport ship can carry and two cases for the total amount of casks used for transportation. First, this study considered the currently accumulated amount of SNF in Korea, and the amount of SNF generated from NPPs until all NPPs are shut down. Then, how much SNF per year must be transported from the NPPs to an interim storage facility was calculated during an assumed transportation period. Second, 24 candidate transportation scenarios were constructed by a combination of the decision factors. To construct viable yearly transportation schedules for the selected 24 scenarios, we created a spreadsheet program named TranScenario, which was developed by using MS EXCEL. TranScenario can help schedulers input shipping routes and allocate transportation casks. Also, TranScenario provides information on the cask distribution in the NPPs and in the interim storage facility automatically, by displaying it in real time according to the shipping routes, cask types and cask numbers that the user generates. Once a yearly transportation schedule is established, TranScenario provides some statistical information, such as the voyage time, the availability of the interim storage facility, the number of transported casks sent from the NPPs, and the number of transported casks received at the interim storage facility. By using this information, users can verify and validate a yearly transportation schedule. In this way, the 24 candidate scenarios could be constructed easily. Finally, these 24 scenarios were compared in terms of their operation cost.

• 한국방재학회:학술대회논문집
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• 2009.02b
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• pp.43-50
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• 2009

Strong ground motion attenuation relationship represents a comprehensive trend of ground shakings at sites with distances from the source, geology, local soil conditions, and others. It is necessary to develop an attenuation relationship with careful considerations of characteristics of the target area for reliable seismic hazard/risk assessments. In the study, observed ground motions from the January 2007 magnitude 4.9 Odaesan earthquake and the events occurring in the Gyeongsang provinces are compared with the previously proposed ground attenuation relationships in the Korean Peninsula to select most appropriate one. In the meantime, a few strong ground motion attenuation relationships are proposed and introduced in HAZUS, which have been designed for the Western United States and the Central and Eastern United States. The selected relationship from the ones for the Korean Peninsula has been compared with attenuation relationships available in HAZUS. Then, the attenuation relation for the Western United States proposed by Sadigh et al. (1997) for the Site Class B has been selected for this study. Reliability of the assessment will be improved by using an appropriate attenuation relation. It has been used for the earthquake loss estimation of the Gyeongju area located in southeast Korea using the deterministic method in HAZUS with a scenario earthquake (M=6.7). Our preliminary estimates show 15.6% damage of houses, shelter needs for about three thousands residents, and 75 life losses in the study area for the scenario events occurring at 2 A.M. Approximately 96% of hospitals will be in normal operation in 24 hours from the proposed event. Losses related to houses will be more than 114 million US dollars. Application of the improved methodology for loss estimation in Korea will help decision makers for planning disaster responses and hazard mitigation.

• Proceedings of the Korea Water Resources Association Conference
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• 2018.05a
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• pp.443-443
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• 2018

새만금유역의 동진강유역에 위치한 동진강제수문은 서해 바닷물 역류에 따른 농경지의 염분피해를 예방하고 고부천과 연계된 부안지역의 농업용수 공급을 위해 설치되었다. 동진제수문은 그간 정읍시 신태인읍, 김제시 부량면, 부안군 백산면의 약 770 ha 농경지에 대해 염분피해를 예방하였고 영농과 한발 시에는 부안군 일대 농경지에 농업용수를 공급할 수 있었다. 하지만 새만금 간척사업등 대규모 국토개발로 주변 자연환경이 크게 변화하여 제수문은 염해방지기능을 상실하게 되었고 현재는 농업용수 공급원으로써의 기능만 남아 있다. 현재 동진강제수문은 관개기에 농업용수 취수를 위해 수문을 닫아 본류의 유량을 저류시키고 있으며, 비관개기에도 대부분 제수문을 닫아놓는 형태로 운영되고 있다. 이러한 갑문폐쇄로 인해 하류의 유입유량이 차단되고 상류 체류시간이 증가되어 수질에 영향을 미칠 것으로 사료된다. 농업용수사용을 위해 저류되어있는 유량을 효율적으로 방류한다면, 외부수자원에 의존하지 않고 유역 내에서 자체적으로 새만금호의 유입량을 확보할 수 있을 뿐만 아니라 동진강 하류의 수질개선에도 기여할 것으로 판단된다. 본 연구에서는 동진강제수문의 내용적을 산정하여 용수공급능력을 파악하였고, 새만금유역과 호 내의 복잡한 수체 형상, 유입 및 유출 구조를 반영하는데 적합한 모델을 적용하였다. 재현성이 검토된 모델 결과를 이용하여 새만금호의 유입부인 동진강 하류의 수질을 모의하였으며, 구성한 모형의 결과와 용수공급능력을 바탕으로 동진강제수문에서의 방류조건을 가정하여 모의를 수행하였다. 방류조건별 수질개선효과를 살펴보면, Scenario 3 > Scenario 2 > Scenario 1의 순서로 수질개선율이 크게 나타났다. 동진강제수문에서의 방류량이 증가할수록 하류의 농도가 점차 감소하는 것으로 나타났으며, 이러한 결과는 동진강제수문의 방류량으로 인해 유황이 개선되고 호 내 오염부하농도가 감소하는 것으로 판단된다. 따라서 농업용수 필요량을 제외한 유량을 하류의 환경유지용수로 확보하고 이를 수질관리취약 시기에 탄력적으로 방류하여 정체수역의 수질오염을 감소시키고 목표수질을 만족하도록 운영되어야 할 것으로 판단된다.