• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2001년도 추계학술대회 논문집
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• pp.103-107
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• 2001

The major studies of an ocean circulation of the East/Japan Sea related to evaluate the feasibility and utilization of deep ocean water are reviewed. The major feature of surface current system of the East/Japan Sea is an inflow of the Tsushima Warm Current through the Korea/Tsushima Strait and the outflow through the Tsugaru and Soya Straits. The Tsushima Warm Current has been known to split into two or three branches in the southern region of the East/Japan Sea. In the cold water region of the East/Japan Sea, the North Korean Cold Current turns to the east near 39$^{\circ}$N after meeting the East Korean Warm Current, then flows eastward. The degree of penetration depends on the strength of the positive wind stress curl, according to the ventilation theory. Various current meter moorings indicate strong and oscillatory deep currents in various parts of the basin. According to some numerical experiments, these currents may be induced by pressure-topography or eddy-topography interaction. However, more investigations are needed to explain clearly the presence of these strong bottom currents. This study concludes the importance of topographical coupling, isopycnal outcropping, different wind forcing and the branching of the Tsushima Warm Current on the circulation of the East/Japan Sea.

• Advances in Energy Research
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• 제5권3호
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• pp.255-275
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• 2017

The advantages of using natural circulation (NC) as a cooling system, has prompted the worldwide development to investigate this phenomenon more than before. The interesting application of the NC in low power experimental facilities and research reactors, highlights the obligation of study in these laminar flows. The inherent oscillations of NC between hot source and cold sink in low Grashof numbers necessitates stability analysis of cooling flow with experimental or numerical schemes. For this type of analysis, numerical methods could be implemented to desired mass, momentum and energy equations as an efficient instrument for predicting the behavior of the flow field. In this work, using the explicit, implicit and Crank-Nicolson methods, the fluid flow parameters in a natural circulation experimental test loop are obtained and the sensitivity of solving approaches are discussed. In this way, at first, the steady state and transient results from explicit are obtained and compared with experimental data. The implicit and crank-Nicolson scheme is investigated in next steps and in subsequent this research is focused on the numerical aspects of instability prediction for these schemes. In the following, the assessment of the flow behavior with coarse and fine mesh sizes and time-steps has been reported and the numerical schemes convergence are compared. For more detail research, the natural circulation of fluid was modeled by ANSYS-CFX software and results for the experimental loop are shown. Finally, the stability map for rectangular closed loop was obtained with employing the Nyquist criterion.

• 대한공간정보학회지
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• 제11권4호
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• pp.29-34
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• 2003

본 연구의 목적은 지리정보유통 활성화를 위한 가격정책 수립측면의 가격산정 기준을 제시하는데 있다. 가격정책은 공급자 측면과 사용자의 측면을 동시에 고려하였다. 본 연구에서 제안한 가격정책에서는 개발단계 비용은 매몰비용으로 산정하였으며, 유지관리 및 갱신비용은 지리정보를 사용하는 사용자에게 부과하였다. 지리정보의 배포비용은 사용매체에 따라 사용자에게 부과하며, 사용목적, 자료의 최신성에 따라 가격을 차등적용 하였다. 또한 지리정보를 유료로 제공하는데 있어 저작권료를 적용해야 한다는 가격정책을 제시하였다. 본 연구에서 수행된 각종 항목을 고려하여 가격산정 기준(안)을 제시하였으며, 이를 통해 지리정보 유통이 더욱 활성화 될 것으로 기대된다.

• 한국유기농업학회지
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• 제21권3호
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• pp.351-362
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• 2013

The Purpose of this paper is to suggest sustainable strategies of the project for developing large-scale environment-friendly agricultural districts (LSEAD). This study used assessment 3 indicators, efficiency, impact and sustainability of environment-friendly agricultural certification area and farmers, management situations of crop-livestock circulation center, educations for environment-friendly farming, changes of farmer's income and so on. This project has contributed to develop environment- friendly agriculture and model of LSEAD. And for sustainable development of LSEAD, it is necessary to renovate crop-livestock circulation centers, promote organic farming of resource-circulation type, converse to non-pesticide or organic farming of low pesticide one, do active marketing activities, establish a governance system of business projects and so forth.

• 대한건축학회논문집:계획계
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• 제35권2호
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• pp.3-10
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• 2019

The purpose of the study is to survey the effective methodology of composition and connection for the third pedestrian routes in mixed-use building by case studies. The study is performed as follows: First of all, pedestrian routes are classified into malling route, evacuation route, and the Third route. Secondly, case studies are conducted based on the classification. Thirdly, it is investigated about the composition and connection of the malling and the Third pedestrian route. The investigation is focused on gate, path, central area, vertical circulation(EV and escalator) and the four circulation elements. Finally, the effective methodology is extracted for setting the Third route in mixed-use buildings. The conclusion of the study is as follows: The enhancement of consistency and connection between the main route and the Third route is important for providing convenient paths especially to users who needs shortcut, EV/ES users. Additionally, the connections between EV and gate, between shortcut and EV/ES should be increased to enable users choosing their path as needed.

• 한국해양공학회지
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• 제14권3호
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• pp.20-28
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• 2000

Using the hydraulic and numerical model of semi-enclosed bay (Chinhae Bay), the efficiencies of flow-control structures on the seawater-circulation in the inner bay were investigated. Expecially, this study was confirmed the effectiveness of the flow-control structures at the mouth and narrow channel of Chinhae Bay through the experiments. The system of flow-control structures could enhance the water exchange improvement appropriately. The results of this study can be used as the long-term and integrated environmental impact assessment model in the inner bay.

• 한국환경과학회지
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• 제29권4호
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• pp.339-349
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• 2020

This study aims to identify participating resident awareness of the improvements to forest carbon cycle villages created by the Korea Forest Service by introducing a system for district heating basedon forest biomass in mountainous areas. Hwacheon Forest Carbon Circulation village was established in Paroho-neureup village in Yuchon-ri, Hwacheon-gun between 2011 and 2013. However, its operation has not been smooth due to the increasing number of households rapidly leaving the district heating system. This study surveyed 76 households that participated in the district heating system using forest biomass in the early stages of the project. This includes households participating in the district heating system(participating households) and households not currently participating in the district heating system(withdrawal households) from September 2019. Surveys focused on the process of participating in forest carbon cycle village projects, and satisfaction in local heating and policy requirements. Of the 67 households, excepting those not allowed to participate in the survey due to death or having moved elsewhere, 36 households participated and 31 households the were in the process of leaving the village were also included. As a result, there was a significant difference between participating and exiting households in the motivation and satisfaction level of district heating. The results of this study are expects to reflect the importance of awareness of residents in the operation of the forest carbon cycle village. This will be utilized as an important dataset for improvement as a means to promote the re-entry if outgoing households. It will also help set the direction of the forest town revitalization project, utilizing forest biomass in the future.

• Nuclear Engineering and Technology
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• 제55권1호
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• pp.330-338
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• 2023

In this study, impacts of an enhanced-moderation Fuel Assembly (FA) named Truly Optimized PWR (TOP) lattice, which is modified based on the standard 17 × 17 PWR FA, are investigated in a natural circulation Soluble-Boron-Free (SBF) Small Modular Reactor (SMR). Two different TOP lattice designs are considered for the analysis; one is with 1.26 cm pin pitch and 0.38 cm fuel pellet radius, and the other is with 1.40 cm pin pitch and 0.41 cm fuel pellet radius. The NuScale core design is utilized as the base model and assumed to be successfully converted to an SBF core. The analysis is performed following the primary coolant circulation loop, and the reactor is modelled as a single channel for thermal-hydraulic analyses. It is assumed that the ratio of the core pressure drop to the total system pressure drop is around 0.3. The results showed that the reactor power could be increased by 2.5% and 9.8% utilizing 1.26/0.38 cm and 1.40/0.41 cm TOP designs, respectively, under the identical coolant inlet and outlet temperatures as the constraints.

• 한국산학경영학회:학술대회논문집
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• 한국산학경영학회 2006년도 춘계학술발표대회 발표논문집
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• pp.103-123
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• 2006

환경문제 해결과 지속적 발전을 위하여 자원순환형 사회시스템이 구축이 논의되고 있으며 물류분야에서도 그 중요성이 부각되고 있다. 본 연구의 목적은 순환형 사회시스템 구축요인인 감량화, 재사용, 재활용과 기업의 물류운영 특성인 통합성, 혁신성, 대응성과의 관계 및 물류성과와의 관계, 이들 요소가 기업규모별로 물류성과에 미치는 효과와 그 영향요인을 분석하여 방향을 제시하고자 하는데 있다. 이 목적을 달성하기 위하여 제조기업을 대상으로 문헌연구와 실증연구를 병행하였다. 본 연구는 기존의 물류 연구들과 달리 자원순환형 사회시스템 구축요인과 물류운영특성이 물류성과에 미치는 영향을 분석하였다는데 의의가 있다고 하겠다.

• 정보관리학회지
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• 제34권1호
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• pp.31-50
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• 2017

본 연구에서는 2001년 개발을 시작으로 학교도서관의 자료 관리를 해결하고, 자료의 공동 활용을 위한 데이터 구축을 지원해 온 DLS의 근본적인 문제점을 조사하고, 이를 해결할 수 있는 개선방안을 모색하고자 한다. 연구방법으로 DLS 전문위원 9명을 대상으로 자료선정, 자료등록, 대출반납, 장서점검, 통계, 이용자검색의 6가지 영역에서 DLS의 사용현황과 문제점을 조사하고 이를 해결할 개선방안을 제안하였다. 자료선정 측면에서는 수서시스템 도입 및 온라인 희망도서 구입신청 기능 추가가 필요하다. 자료등록 측면에서는 데이터 품질 관리 향상과 검색기능 향상을 위한 색인어의 체계적 입력 및 어휘통제가 필요하다. 대출반납 측면에서는 대출속도 향상이, 장서점검 측면에서는 폐기자료의 복원 기능이, 통계 측면에서는 정확한 통계자료 생성이 필요하다. 이용자검색에서는 검색속도 향상 및 이용자 인터페이스 기능 향상이 필요하다. 본 연구는 앞으로 DLS 시스템 개선에 많은 기여를 할 것이며 이에 따라 DLS 이용도 향상될 것이다.