• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.34 no.12
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• pp.75-81
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• 2006

In this paper, the 6-dof electric motion platform system designed for the helicopter simulator satisfying the class of the CASA(Civil Aviation Safety Authority) level 2 is presented. From the kinematic, dynamic and structural analyses for motion base and electrical actuator systems, we show the feasibility of the developed motion platform system by producing the acceptable results of the test and evaluation according to the requirements specified in the CASA level 2. Furthermore through this development we suggest newly the adaptability of the electrical actuator system up to 10 ton class motion platform system, whose usage will be broaden rapidly, substituting with the advantage over the conventional hydraulic system.

• Proceedings of the Korea Water Resources Association Conference
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• 2004.05b
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• pp.532-536
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• 2004

최근 수자원개발의 한계와 수질의 오염으로 인하여 제한된 수자원의 적절한 배분과 지속 가능한 수자원의 이용이라는 문제가 크게 대두되고 있어 개발의 한계 속에서 수질을 보존하기 위한 노력이 필요한 시점이다. 그러나, 수량과 수질을 동시에 고려할 수 있는 수자원계획 도구는 흔치 않다. 이러한 종합적인 수자원계획 수립 및 분석을 위할 도구를 개발하기 위하여 한국건설기술연구원에서는 SEI-B(Stockholm Environment Institute - Boston Center)와 공동으로 기존에 SEI-B에서 개발된 WEAP(Water Evaluation And Planning System)을 국내 실정에 맞도록 수정보완 한 K-WEAP을 개발하였었다. 이를 바탕으로 본 연구에서는 K-WEAP에 수질 모의 기능을 추가하여 개발함으로써 수량-수질을 연계하여 수자원계획수립이 가능하도록 하였다. 개발된 K-WEAP은 원단위 개념을 이용한 발생량의 산정과 보존성 물질의 수질 모의와 일반적인 지수감소형 물질 및 BOD, DO 등과 같은 1차 분해성 물질의 모의가 가능하다. 이러한 기능을 이용하여 수자원 계획 시 수질등급을 만족시키기 위한 하수처리장의 설치 계획과 유역관리를 위한 여러 가지 대안의 수립이 가능하며, 여러 가지 대안에 대하여 장래 수질의 변화 경향을 비교 분석할 수 있는 기초 자료를 제공한다. 본 연구에서는 K-WEAP에 탑재된 수질 모형의 내용을 분석하고 수량과 수질의 통합과정을 알아본 후, 가상의 시험유역에 적용한 길과를 바탕으로 수량-수질 통합수자원계획의 적용성을 살펴보았다,

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2017.05a
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• pp.120-127
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• 2017

High temperature oxygen and water vapor was generated from catalytic decomposition of rocket grade highly concentrated hydrogen peroxide, and monopropellant thruster system was developed and applied into space propulsion system. In this research, background research and conceptual design of underwater propulsion system using catalytic decomposition of hydrogen peroxide was progressed. Two types of system was designed with different steam injection methods. Propulsion system that has ring-type steam injector was manufactured and performance estimation of system was performed with different nozzle exit area. Performance evaluation with central steam injection type jet engine will be progressed in the future.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.5A
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• pp.623-629
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• 2008

New high strength bolts are required due to the development of the high strength steel, the ultra-thick steel plates, and the long-span bridge, though high strength bolts with tensile strength of 1,000 MPa are mainly used in construction site of every country. Consequently, in this study, we estimated the fatigue strength by performing fatigue test of slip-resistant splices with slip coefficients applying the newly developed F13T high strength bolts. The fatigue test satisfied the Category B requirements with the fatigue strength of slip-resistant splices. Also we analyzed the fatigue fracture characteristics of slip-resistant splices.

• The Journal of the Convergence on Culture Technology
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• v.9 no.3
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• pp.851-859
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• 2023

This paper proposes a web service that provides consumers with necessary information to make rational purchases of bottled water. The web service or dedicated mobile application introduced in this paper offers brand-specific manufacturer information and bottled water brand information produced by manufacturers. In addition, detailed information about the manufacturer such as location, environmental quality grade of the Ministry of Environment, and brand/capacity-specific prices are provided to consumers who use the proposed service in this paper. By utilizing the proposed service in this paper, users can receive guidance on how to make rational purchases of the bottled water they need, enabling them to consume economically and healthily.

• Journal of radiological science and technology
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• v.32 no.4
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• pp.461-469
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• 2009

To predict the tumor grading, various imaging modalities have been applied clinically. This study determines clinical usefulness of perfusion MRI, using relative cerebral blood volume in grading of the gliomas. We did a retrospective review of 17 patients (mean age, 57.5 years; 11 male, 6 female) who underwent perfusion MR and conventional MRI, and then correlated pathologically after operation. Statistical analysis of regional cerebral blood volume and relative cerebral blood volume(rCBV) was performed by using softwares such as PAT by SIEMENS and Xmap ver 2.0 developed by ourselves. Six patients out of 13 were low-grade gliomas while eleven patients were the high-grade gliomas. Mean relative CBV (m_rCBV/white matter) in the low-grade gliomas was 1.62, and mean relative CBV(m_rCBV/cortex) was 0.12. In the high-grade gliomas, mean relative CBV(m_rCBV/white matter) and mean relative CBV(m_rCBV/cortex) were 33.53 and 0.96. Mean relative CBV of gliomas were elevated with a statistical difference(P<.05), compared with contralateral white matter(P=.019) or cortex(P=.025). Furthermore mean relative CBV(m_rCBV/white matter) was much higher than mean relative CBV(m_rCBV/cortex). Perfusion MRI using regional cerebral blood volume and rCBV is very useful imaging modality for grading the glioma.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2004.11a
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• pp.504-509
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• 2004

Safety assessment of construction projects may be affected by various factors such as types and scale of projects, construction methods, procedure, climactic, and site conditions etc. Presently, in planning and design phases, designers are still often uncertain of their responsibilities, l3i]I information and training of safety. Therefore, designers are still failing to exploit the potential that have to eliminate and reduce risks on site. In this study, the concepts of safety impact assessment is introduced in order to derive the performing design for safety in design phase. For this purpose, a framework for safety impact assessment model using risk-based approach for construction projects is suggested. The suggested model includes of information survey and scenarios, classification of safety impact factors occurred by design and construction, and quantitative estimation of magnitude and frequency. Moreover, the checklist which is enable to identify relationship between safety impact factors and design factors is developed and the methodology of safety impact assessment model using risk-based approach is also proposed.

• Journal of Korea Water Resources Association
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• v.55 no.8
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• pp.589-601
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• 2022

Although drought is a natural phenomenon, its damage occurs in combination with regional physical and social factors. Especially, related to the supply and demand of various waters, drought causes great socio-economic damage. Even meteorological droughts occur with similar severity, its impact varies depending on the regional characteristics and water supply system. Therefore, this study assessed regional drought risk considering regional socio-economic factors and water supply system. Drought hazard was assessed by grading the joint drought management index (JDMI) which represents water shortage. Drought vulnerability was assessed by weighted averaging 10 socio-economic factors using Entropy, Principal Component Analysis (PCA), and Gaussian Mixture Model (GMM). Drought response capacity that represents regional water supply factors was assessed by employing Bayesian networks. Drought risk was determined by multiplying a cubic root of the hazard, vulnerability, and response capacity. For the drought hazard meaning the possibility of failure to supply water, Goesan-gun was the highest at 0.81. For the drought vulnerability, Daejeon was most vulnerable at 0.61. Considering the regional water supply system, Sejong had the lowest drought response capacity. Finally, the drought risk was the highest in Cheongju-si. This study identified the regional drought risk and vulnerable causes of drought, which is useful in preparing drought mitigation policy considering the regional characteristics in the future.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2019.05a
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• pp.464-466
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• 2019

Controllers used in nuclear power plants require high reliability. A controller including a Field Programmable Gate Array (FPGA) and a Complex Programmable Logic Device (referred to hereinafter as FPGA) has been applied to many Nuclear Power Plants (NPP) in the past, including the APR1400 (Advanced Power Reactor 1400), a Korean digital nuclear power plant. Initially, the FPGA was considered as a general IC (Integrated Circuit) and verified only by device verification and performance testing. In the 1990s, research on FPGA verification began, and until the FPGA became a chip, it was regarded as software and the software Verification and Validation (V&V) using IEEE 1012-2004 was implemented. Currently, IEC 62566, which is a European standard, has been applied for a lot of verification. This method has been evaluated as the most sensible method to date. This is because the method of verifying the characteristics of SoC (System on Chip), which has been a problem in the existing verification method, is sufficiently applied. However, IEC 62566 is a European standard that has not yet been adopted in the United States and maintains the application of IEEE 1012 for FPGA. IEEE 1012-2004 or IEC 62566 is a technical standard. In practice, various methods are applied to meet technical standards. In this paper, we describe the procedure and important points of verification method of Nuclear Safety Class FPGA applying SoC verification method.

• The Journal of Engineering Geology
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• v.32 no.3
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• pp.327-338
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• 2022

This study aims to empirically and statistically predict soil depths across areas affected by landslides. Using soil depth measurements from a landslide area in Korea, two sets of soil depths are calculated using a Z-model based on terrain elevation and a probabilistic statistical model. Both sets of calculation results are applied to derive landslide risk using the saturated infiltration depth ratio of the soil layer. This facilitates analysis of the infiltration of rainfall into soil layers for a rainfall event. In comparison with the probabilistic statistical model, the Z-model yields soil depths that are closer to measured values in the study area. Landslide risk assessment in the study area based on soil depth predictions from the two models shows that the percentage of first-grade landslide risk assessed using soil depths from the probabilistic statistical model is 2.5 times that calculated using soil depths from the Z-model. This shows that soil depths directly affect landslide risk assessment; therefore, the acquisition and application of local soil depth data are crucial to landslide risk analysis.