• 한국안전학회지
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• 제22권4호
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• pp.1-6
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• 2007

In this study, we provided an index for the quantitative and systematic performance based fire risk assessment. A complex cinema was adopted for the fire scenario and the fire simulation was carried out by using FDS. Also evacuation time was calculated by using SIMULEX. We obtained a big different fire risk assessment result by the focus on the between space basis and the time basis. As a result of this study, performance based fire risk assessment should be performed on the basis of individual evacuee's path line.

• 대한전기학회논문지:전력기술부문A
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• 제54권9호
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• pp.441-448
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• 2005

On-line dynamic security assessment is becoming more and more important for the stable operation of power systems as load level increases. The necessity is getting apparent under Electricity Market environments, as operation of power system is exposed to more various operating conditions. For on-line dynamic security assessment, fast transient stability analysis tool is required for contingency selection. The TEF(Transient Energy Function) method is a good candidate for this purpose. The clustering of critical generators is crucial for the precise and fast calculation of energy margin. In this paper, we propose a new method for fast decision of mode of instability by using stability indices. Case study shows very promising results.

• 한국소프트웨어감정평가학회 논문지
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• 제17권2호
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• pp.151-159
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• 2021

도표로 작성된 양식 문서에서 도표의 레이아웃 해석에 필요한 그리드 라인을 추출하기 위해 다양한 필터링 또는 모폴로지 등의 방법을 사용하여 직선 성분을 선명하게 개선시키기 위한 연구들이 많이 진행되고 있다. 도표의 직선 성분을 선명화하더라도 직선 내부에 절단 점들이 존재하거나 기울어진 경우에는 직선 추출이 어렵고 도표 셀들의 레이아웃을 논리적으로 표현하는데 여전히 어려움을 겪을 수 있다. 본 연구에서는 직선에 절단점들이 존재하거나 기울어져도 직선을 검출할 수 있는 라인 추적 알고리즘을 제안하였다. 이를 이용하여 그리드 라인을 추출하고 라인들의 교차점 및 셀 정보들을 찾아 도표의 구조를 분석할 수 있는 알고리즘을 마련하였다. 제안한 알고리즘을 실제 양식 문서 영상을 대상으로 실험한 결과 평균 0.41초 처리시간에 96.4%의 도표 구조를 분석할 수 있음을 확인하였다.

• International Journal of Automotive Technology
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• 제8권3호
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• pp.375-382
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• 2007

The multi-driver off-road vehicle drive-line consists of many components, with close connections among them. In order to design and analyze the drive-line efficiently, a modular methodology should be taken. The aim of a modular approach to the modeling of complex systems is to support behavior analysis and simulation in an iterative and thus complex engineering process, by using encapsulated submodels of components and of their interfaces. Multi-driver off-road vehicles are comparatively complicated. The driving-line is an important core part to the vehicle, it has a significant contribution to the performance. Multi-driver off-road vehicles have complex driving-lines, so performance is heavily dependent on the driving-line. A typical off-road vehicle's driving-line system consists of a torque converter, transmission, transfer case and driving-axles, which transfers the power generated by the engine and distributes it effectively to the driving wheels according to the road condition. According to its main function, this paper proposes a modularized approach for design and evaluation of the vehicle's driving-line. It can be used to effectively estimate the performance of the driving-line during the concept design stage. Through an appropriate analysis and assessment method, an optimal design can be reached. This method has been applied to practical vehicle design, it can improve the design efficiency and is convenient to assess and validate the performance of a vehicle, especially of multi-driver off-road vehicles.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1995년도 추계학술대회 논문집 학회본부
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• pp.131-136
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• 1995

This paper presents a functional ability improvement of auto-reclosing relay in the power transmission line protection. When the high speed auto-reclosing is successful, Auto-reclosing is practically valuable to improve the transient stability limit of a power system, but it is fail due to surviving fault, both electrical and mechanical stresses can result on the transformers and turbine-generator. It is true that the longer dead time of the reclosing relay gives the higher rate of successful reclosing, On the other hand, the power system does not always need high speed reclosing because of enough stability margin. This paper proposed "stability margin based dead time reclosing" in order to decrease not only the rate of unsuccessful reclosing, but the possibility of the harmful stress also. On-line transient stability assessment using artificial neural network, for implementing the proposed scheme, has studied and tested with resonable results.

• 한국해양공학회지
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• 제23권1호
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• pp.135-139
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• 2009

In the line heating for the plate forming of a ship's hull, an in line assessment of completion is necessary for an automated production system. In the current curved plate forming process, a fabricated plate is compared to a template that is made in the mold loft and is used for the determination of the heating line for the next step. In this paper, a new method is presented for the in line assessment of completion for curved plate forming. This method uses a 3-D scanner. For the registration of the scanned data for a surface and the target surface, the ICP (Iterative Closest Points) method was adopted. A computer program was developed to carry out the registration, check for similarities, visualize the surface, and control the results. This program was applied to a sample curved plate forming process.

• 대한안전경영과학회지
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• 제8권3호
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• pp.51-66
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• 2006

This study was attempted to analyze risk factors and suggest accident prevention in live line works for power transmission lines to be developed and applied in Korea. Safety problem cannot but occur at development of live line works and application to the field. With respect to this, problems likely to occur in the field among works adopting methods of works including live line works for power transmission lines were investigated and analyzed through documentary survey and risk assessment method. The results are summarized as follows. A risk assessment method model was suggested. This method enables scientific and systematic development of safety control. That is, the owner may autonomously induce safety control and build risk assessment database by work process to use them as best training data for workers. Also, in the field, it may induce all workers to participate in safety program and secure safety by making workers seek for safety working method under smooth flow from looking at risk factors to accident prevention activities. It is deemed that this humble study will prevent both accident and injury likely to occur in live line works for power transmission lines.

• 대한전기학회논문지:전력기술부문A
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• 제48권2호
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• pp.107-114
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• 1999

This paper presents an application of artificial neural networks(ANN) to assess the dynamic security of power systems. The basic role of ANN is to provide assessment of the system's stability based on training samples from off-line analysi. The critical clearing time(CCT) is an attribute which provides significant information about the quality of the post-fault system behaviour. The function of ANN is a mapping of the pre-fault, fault-on, and post-fault system conditions into the CCT's. In previous work, a feed forward neural network is used to learn this mapping by using the generation outputs during the fault as the input data. However, it takes significant calculation time to make the input data through the network reduction at a fault as the input data. However, it takes significant calculation time to make the input data through the network reduction at a fault considered. In order to enhance the speed of security assessment, the bus data and line powers are used as the input data of the ANN in thil paper. Test results show that the proposed neural networks have the reasonable accuracy and can be used in on-line security assenssment efficiently.

• 조명전기설비학회논문지
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• 제25권6호
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• pp.115-121
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• 2011

Intelligent distribution equipment is inevitable to realize self-healing which is one of smart grid functions in distribution network. Therefore, most of distribution equipment have been developed with self diagnostic sensors. However, it is not effective to construct on-line monitoring system for underground distribution cable because of high cost and low sensitivity. Recently, optical fiber composite cable is being considered for communication and power delivery in order to cope with increasing communication in distribution network. This paper presents the design and performance assessment results of underground cable on-line monitoring system using DTS(Distributed Temperature Sensing) and optical fiber composite underground cable.

• Structural Engineering and Mechanics
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• 제6권7호
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• pp.773-784
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• 1998

To assess the collapse risk of transmission line structures subject to natural hazards, it is important to identify what hazard may cause the structural collapse. In Australia and many other countries, a large proportion of failures of transmission line structures are caused by severe thunderstorms. Because the wind loads generated by thunderstorms are not only random but time-variant as well, a time-dependent structural reliability approach for the risk assessment of transmission line structures is essential. However, a lack of appropriate stochastic models for thunderstorm winds usually makes this kind of analysis impossible. The intention of the paper is to propose a stochastic model that could realistically and accurately simulate wind loading due to severe thunderstorms. With the proposed thunderstorm model, the collapse risk of transmission line structures under severe thunderstorms is assessed numerically based on the computed failure probability of the structure.