• Bulletin of the Society of Naval Architects of Korea
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• v.21 no.2
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• pp.35-42
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• 1984

A line integral is exhibited which has the same value for all paths surrounding the tip of crack in a two dimensional strain field of elastic-plasticc material. Finite element method was used to determine Rice's J-integral value in centrally cracked plate. These numerical J-integral values were compared with corresponding values of reference with low hardening and high yield strength. The J-integral value was also computed for a crack extension and different load condition. For increasing crack length the value of J-integral also increases, this means that the crack is unstable. To prove path independent, three paths were used in the analysis and proved.

• Korean Journal of Computational Design and Engineering
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• v.7 no.3
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• pp.141-147
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• 2002

Profile machining using cutter diameter compensation is widely used in die and mould manufacturing. Especially automotive die makers try to use 3D-profile machining for trimming or flange dies. But the technological requirements and implementation issues haven't been defined. In this paper we summarized the requirements and issues of 3D-profile machining. Approximation of input profiles into sequences of line and helical arc is the first major issue. The second major issue is removing cutter inter- ference from the approximated curves holding z-values when the maximum cutter diameter is given. Keeping constant machining width, local machining, path linking problems and several detail technological requirements are also discussed.

• Proceedings of the Korean Society of Computer Information Conference
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• 2015.07a
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• pp.63-66
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• 2015

본 논문에서는 미러링 환경에서 동작하는 악성링크 차단 및 URL 필터링 시스템에서 URL 접속을 차단할 수 있는 페이지 리다이렉션 기술을 소개한다. 미러링(Mirroring: Out of Path) 환경에서 URL 패킷을 차단하기 위해서 많이 사용하고 있는 방법으로는 RST (Reset) 패킷을 전송하여 세션을 종료하는 방법이다. 이 방법은 요청 서버에 RST(Reset) 패킷을 보내 강제로 종료하는 방식이기 때문에 사용자에게 접근 차단과 관련된 상태 등의 정보를 알려줄 수 없다. 현재 인라인(In-line) 방식에서 사용되고 있는 페이지 리다이렉션 기술을 미러링 환경에서 구현하여 사용자에게 차단 정보를 보여줄 수 있으며 다양한 장비 개발 환경에서 유용하게 사용할 수 있는 기술이라고 판단한다.

• Journal of Korean Vacuum Science & Technology
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• v.7 no.1
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• pp.1-7
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• 2003

The pressure distributions in the test stand built for developing KSTAR NBI ion sources were obtained using a network system composed of conductance elements modeling the ion source, the neutralizer, and other beam line components. The allowable regime was defined on the coordinates of the gas supply rate to the ion source and the neutralizer, considering the proper conditions of the three critical parameters, the ion source pressure for good arc discharge, the pressure integral in the neutralizer for sufficient neutralization, and the chamber pressure for minimum neutral beam loss. The neutral beam evolution along the path from the ion source extraction grid to the calorimeter through the neutralizer, the bending magnet and the vacuum chamber was estimated for typical pressure distributions.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.45 no.2
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• pp.310-318
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• 1996

It is very important for a mobile robot to estimate its current position With precise information about the current position, the mobile robot can do path-planning or environmental map building successfully. In this paper, a position estimation method using one color image is presented. The mobile robot(K2A) takes an image of a corridor and searches for the door and pillar, which are the given landmarks. The color information is used to distinguish the landmarks. In order to represent the presence of the landmarks, Image Mode is defined. This method adopts Kullback information distance. If a landmark is detected, with the color information, the mobile robot identifies the vertical line of the landmark and its crossing point and an experimental navigation is performed.

• Journal of the Korean Home Economics Association
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• v.38 no.12
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• pp.111-129
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• 2000

The purpose of this study is to investigate the level of consumer instantly impulse buying in cuber market user. Also this study analyzes causal effect on consumer instantly impulse purchasing by demographic and social, place and promotion, consumer emotion state, and consumer internal and psychological variables. The data had been collected from on-line research method with 1,034, as using cuber market. The major statistical methods used for data analysis are frequency, percentile, mean, factor analysis, multiple regression analysis, Pearson's correlation analysis, and path analysis. The result of causal effect analysis were as follows; First, the variables affecting possession oriented materialism were sex and age. Second, the variables affecting self-control were sex, income, account of credit card, and instantly state of mind. Third, variables directly affecting instantly impulse purchasing were serif employed, banner advertisement, experience of cuber shopping, shopping mall pattern, instantly state of mind, purpose of shopping, happiness and success oriented materialism, and self-control. Also sex, income account of credit card, and instantly state of mind emerge to indirectly effect via self-control. Especially, the variables of success oriented materialism and instantly state of mind influenced on the highest of relative variables in consumer instantly impulse purchasing.

• Journal of Power Electronics
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• v.11 no.5
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• pp.655-661
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• 2011

This paper presents two topologies for single-stage single-phase double-buck type PFC converters, designed to operate at high power factor, near sinusoidal input currents and adjustable output voltage. Unlike the known buck type PFC topologies, in which the output voltage is always lower than the maximum input voltage, the proposed converters can operate at output voltages higher than the ac input peak voltage. A reduced number of switches on the main path of the current are another characteristic of the two proposed topologies. To shape the input line currents, a fast and robust controller based on a sliding mode approach is proposed. This active non-linear control strategy, applied to these converters allows high quality input currents. A Proportional Integral (PI) controller is adopted to regulate the output voltage of the converters. This external voltage controller modulates the amplitude of the sinusoidal input current references. The performances of the presented rectifiers are verified with experimental results.

• Proceedings of the KIEE Conference
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• 1999.07g
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• pp.2989-2991
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• 1999

We design the stable controller with variable gains and reference velocity in order to apply to this controller the proper gains and reference velocity generated with fuzzy logic in on-line. The proposed controller is applied to solve two problems including the reference velocity tracking problem and speedy tracking problem. The result of the simulation show a robust performance under the different conditions

• Proceedings of the KIEE Conference
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• 2003.07d
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• pp.2414-2416
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• 2003

In this raper, we present a Wavelet Neural Network(WNN) approach to the solution of the tracking problem for mobile robots that possess complexity, nonlinearity and uncertainty. The neural network is constructed by the wavelet orthogonal decomposition to form a wavelet neural network that can overcome the problems caused by local minima of optimization and various uncertainties. This network structure is helpful to determine the number of the hidden nodes and the initial value of weights with compact structure. In our control method, the control signals are directly obtained by minimizing the difference between the reference track and the pose of a mobile robot that is controlled through a wavelet neural network. The control process is a dynamic on-line process that uses the wavelet neural network trained by the gradient-descent method. Through computer simulations, we demonstrate the effectiveness and feasibility of the proposed control method.

• Proceedings of the KIEE Conference
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• 2003.07d
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• pp.2453-2455
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• 2003

We propose a path planning method to reduce the inspection time of AOI (automatic optical inspection) machines in SMT (surface mount technology) in-line system. Inspection windows of board should be clustered to consider the FOV (field-of-view) of camera. The number of clusters is desirable to be minimized in order to reduce the overall inspection time. We newly propose a genetic algorithm to minimize the number of clusters for a given board. Comparative simulation results are presented to verify the usefulness of proposed algorithm.