• 대한안전경영과학회지
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• 제8권2호
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• pp.115-128
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• 2006

The study analyzes those relations of customer service level of each sales branch, level of cooperations among branches, and overall system-wide service level for an item. Under the continuous review method, each sales branch places an order to the outside supplier, and the each branch receives the order quantity after elapsing a certain lead time. Under these circumstances, those branches with stockout condition may be supplied by other branches with keeping stocks to cover the shortages. This policy generally increases the system-wide customer service level for an item throughout cooperations for the safety plan among branches. Therefore, in the context of inventory policy, the decision rules to determine the proper branch levels of service and cooperation levels of service are important goals in terms of attaining desired system-wide service level. This research has suggested the method and procedure to reach above goals.

• 한국정밀공학회지
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• 제15권2호
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• pp.35-44
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• 1998

This paper describes multiple fault diagnosis method in complex system with hierarchical structure. Complex system is divided into subsystem, item and component. For diagnosing this hierarchical complex system, it is necessary to implement special neural network. We introduced Modular Artificial Neural Network(MANN) for this purpose. MANN consists of four level neural network, first level for symptom classification, second level for item fault diagnosis, third level for component symptom classification, forth level for component fault diagnosis. Each network is multi layer perceptron with 7 inputs, 30 hidden node and 7 outputs trained by backpropagation. UNIX IPC(Inter Process Communication) is used for implementing MANN with multitasking and message transfer between processes in SUN workstation. We tested MANN in reactor system.

• Journal of Electrical Engineering and Technology
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• 제13권5호
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• pp.2033-2044
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• 2018

This study presents states-of-the art overview of the system level electrostatic discharge (ESD) analysis and testing. After brief description of ESD compliance standards and ESD coupling mechanisms, the study provides an in-depth review and comparison of the various techniques for the system level ESD coupling analysis using time and frequency domain techniques, full wave electromagnetic modeling and hybrid modeling. The methods used for improving system level ESD testing using troubleshooting and determining the root causes of soft failures, the optimization of ESD testing and the countermeasures to mitigate ESD problems are also discussed.

• International Journal of Computer Science & Network Security
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• 제24권2호
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• pp.169-177
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• 2024

Interacting Spherical tank has maximum storage capacity is broadly utilized in industries because of its high storage capacity. This two tank level system has the nonlinear characteristics due to its varying surface area of cross section of tank. The challenging tasks in industries is to manage the flow rate of liquid. This proposed work plays a major role in controlling the liquid level in avoidance of time delay and error. Several researchers studied and investigated about reducing the nonlinearity problem and their approaches do not provide better result. Different types of controllers with various techniques are implemented by the proposed system. Intelligent Adaptive Neuro Fuzzy Inference System (ANFIS) based Sliding Mode Controller (SMC) with Fractional order PID controller is a novel technique which is developed for a liquid level control in a interacting spherical tank system to avoid the external disturbances perform better result in terms of rise time, settling time and overshoot reduction. The performance of the proposed system is obtained by analyzing the simulation result obtained from the controller. The simulation results are obtained with the help of FOMCON toolbox with MATLAB 2018. Finally, the performance of the conventional controller (FOPID, PID-SMC) and proposed ANFIS based SMC-FOPID controllers are compared and analyzed the performance indices.

• 한국통신학회논문지
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• 제31권6A호
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• pp.563-574
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• 2006

본 논문에서는 OFDM(Orthogonal Frequency Division Multiplexing) 기반 다중 안테나 시스템의 링크레벨 성능 분석을 위하여 실제 전파 환경과 유사한 특성을 갖는 Ray-tracing 방식 채널의 하나인 SCM(Spatial Channel Model) 채널을 구현한다. 3GPP & 3GPP2 Spatial Channel AHG(Ad-hoc Group)에서 시스템레벨 성능 비교용으로 제안한 SCM 채널을 링크레벨 성능의 비교 분석을 위하여, 본 논문에서는 시스템레벨 채널에 대한 채널 계수 및 파라메터들을 링크레벨 성능 비교용으로 변환하여 구현한다. 모의실험을 통하여 구현한 SCM 채널의 특성을 검증하고, 이를 이용하여 기존의 OFDM 기반 MIMO (Multiple Input Multiple Output) 적용 시스템 및 스마트 안테나 적용 시스템에서의 실제적인 링크레벨 성능을 분석하고, 정확한 비교 검증을 위하여 SCM 채널과 동일한 파라메터를 적용한 I-METRA 채널 및 독립 채널 상황에서의 링크 레벨 성능을 함께 비교 분석한다. MIMO 및 스마트 안테나 적용 시스템에 대하여 여러 채널 환경에서 채널 상관도에 따른 링크레벨 성능을 분석함으로써, 채널 상관도의 영향에 따라 주어진 환경에 적합한 다중 안테나 시스템을 제안한다.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2001년도 추계종합학술대회
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• pp.300-303
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• 2001

The first 7 years of altimeter data from the TOPEX/POSEIDON (T/P) were analyzed to study the surface circulation and its variability in the East Asian Marginal Seas. Long term averaged T/P sea level time series data where compared with in situ sea level measurements from a float-operated type tide gauge around of south Korea and Japan. T/P data are a large contaminated by 60-day tidal aliasing effect, very near the alias periods of M2 and S2. When this 60-day effect is removed, the data agree well with the tide gauge data with 4.6 cm averaged RMS difference. The T/P derived sea level variability reveals clearly the well-known, strong current-topography such as Kuroshio. The T/P mean sea level of North Pacific (NP) was higher than Yellow Sea (YS) and East Sea (ES). The T/P sea level valibility, with strong eddy and meandaring, was the largest in eastern part of Japan and this variability was mainly due to the influence of bottom topography in Kuroshio Extention area.

• 한국BIM학회 논문집
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• 제7권2호
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• pp.25-35
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• 2017

Building information modeling (BIM) can improve to communicate with project participants by early construction involvement (ECI) from the beginning of the project. Therefore, they can minimize design changes and improve design quality and construction. However, because there is insufficient research on the scope and application level of BIM according to project delivery system and project characteristics, construction companies have efficiently not been using the BIM. Therefore, this study intends to conduct basic research as a basis for confirming appropriate BIM application and level according to project delivery system and project characteristics. To do this, we investigated the project delivery system and project characteristics of domestic and foreign projects that have successfully applied BIM, and compare and analyze them based on BIM application and BIM level framework derived from theory reviews and experts. Therefore, this study can be used as a basis for strategically establishing the scope and level of BIM according to project delivery system and project characteristics through the result of this study.

• 한국철도학회논문집
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• 제5권2호
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• pp.112-117
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• 2002

Reduction of noise level in the cabin of urban transit unit is an important issue to enhance the comfortability of passengers. It is made clear that a cause of increased noise level in cabin is the imperfect airtightness of entrance doors. In this study, the sliding-plug door system is developed to reduce the noise level of cabins by securing the airtightness of entrance door. The sliding-plug door system is composed of air-driven engine, swing arms, guide rails, guide rollers and locking devices. It is economical owing to using the previous door engine system. It is also adequate for the platform system of our subway station. It was tested to prove the reliability of system and was applied to standard urban transit unit. The effectiveness of noise reduction in cabin resulting form the sliding-plug door system was confirmed by test results.

• 전기전자학회논문지
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• 제28권2호
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• pp.204-208
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• 2024

본 논문에서는 ESD 보호회로의 전류구동 특성을 향상시키기 위해 일반적인 저전압용 ESD 보호회로인 LVTSCR의 구조적 변경을 적용한 ESD 보호회로를 제안한다. LVTSCR 구조에서의 electric field와 ESD 전류 경로가 형성 되는 영역을 분리하여 전력 소모를 최소화 하였으며 이에 대한 전기적 특성을 분석하고 전류 구동 특성을 개선하였다. 시뮬레이션을 통한 System-level 특성 저하에 기인하는 구조적인 문제를 분석하였으며 이를 반영하여 특성을 검증하였다. 제안된 ESD 보호회로의 전기적 특성은 TCAD 시뮬레이션을 통해 검증하였으며 HBM 모델링 및 System-level 모델링을 통해 분석하였다. 또한, DB-Hitek사의 0.18um BCD 공정을 통해 silicon 제작 및 HBM 10kV 특성 검증하였다.

• 한국전자통신학회논문지
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• 제6권2호
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• pp.249-255
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• 2011

국방분야 무기체계 형상관리를 위한 자료관리 정보체계인 국방조달관리체계와 국방형상관리정보체계에 대하여 상호운용성수준을 측정하고, 측정된 결과를 분석하여 두 정보체계간의 상호운용성 수준을 판단하여, 장차 정보체계 성능개선사업시 반영하기 위한 방향을 제시하였다.