• Journal of Advanced Marine Engineering and Technology
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• v.27 no.7
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• pp.879-888
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• 2003

Swirling air flow in a horizontal round tube was experimentally studied for its visualization. The present investigation deals with swirl angle, flow visualization studies and accompanying vortex core behavior by using oil smoke and a hot wire anemometer for Re = 40,000 and 50000 at X/D = 41, 59 and 71. In the swirl air flow, a vortex core was formed at high swirl intensity along the test tube. The swirl angle and the vortex core depended on the swirl intensity along the test tube. The results of swirl angles measured by flow visualization and hot wire reasonably agree with those of previous studies.

• Journal of the Korean Society for Railway
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• v.9 no.4 s.35
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• pp.419-424
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• 2006

In this paper we study on a method to predict and to demonstrate the reliability of the Korea high speed train control system in quantitative point of view. For the prediction of the reliability in train control system which is composed of electronic parts, Relax Software 7.7 automation tool is employed and MIL-HDBK-217 Handbook that is a standard for the prediction of the failure rate in electronic components is used. Mean Time Between Failure (MTBF) is predicted based on the failure rate of the subsystems, State Modeling and Markov Modeling method is used to express a reliability function of the train control system composed by hardware redundancy as a function of time. We propose a Reliability Test which is performed on the level of the subsystems and Failure Report, Analysing, Correction action system which use the test operation data to prove the predicted reliability.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 1995.03a
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• pp.252-263
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• 1995

It is visualized that dislocations move straightly in polycrystalline structure and the trans-grain dislocation moving occur from yield point to ultimate tensile stress. Some fracturemodes in uniaxial tensile test are ilustrated in order to explain that after the ultimate point the grains deforms by twins and the rotations of grains make cracks at the grain-boundaries by the incompatibility . The luders banks. which propagates along the axis of the specimen, are twin bands whcih are formed by rearrangement of the atoms within the structure of three-dimensional crystallizing $\pi$-bondings. The fatigue limit can be found through the atom's rolling back motion during elastic deformation inthe uniaxial tensile test by the change of the gradient.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.239-240
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• 2008

Korea Electric Power Research Institute has being carried out an IEC 61580 communication service test on IED trial products developed related to power IT project, "Development of Prototype for Advanced Substation Automation System based on the Digital Control Technology". This paper describes GOOSE testing, one of the IEC 61850 conformance testing items, which consists of 14 publish and subscribe test cases.

• Journal of the Korean Operations Research and Management Science Society
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• v.17 no.1
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• pp.85-106
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• 1992

Much attention currently is being aimed to OA (office automation). OA has a potential for improving management decision making as well as increasing productivity of secretarial and clerical workers. This study construct a model that may be useful to the OA manager, in channeling OA efforts in the right direction. The purpose of this study is to analyze the improtance of critical success strategy for OA implementation, to test 5 hypotheses and 11 subsidiary hypothese of organizational characteristics and OA propulsion characteristics, and to suggest and evaluate a cussess strategy for OA implementation. The population consists of the Korean business in Seoul, 292 response of the 1000 questionaires were available and analyzed. The analytical methods are adopted on the frequency analysis to analyze the general characteristics, the one-way ANOVA, the Pearson's correlation analysis, the regression analysis for the test of the hypotheses.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.51 no.6
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• pp.302-310
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• 2002

This paper presents an application of a improved branch exchange (IBE) algorithm with a tie branch power (TBP) flow equation to solve the Optimal Routing problem for operation of a radial Power system including power distribution system. The main objective of the Optimal Routing problem usually is to minimize the network real power loss and to improve the voltage profile in the network. The new BE algorithm adopts newly designed methods which are composed by decision method of maximum loss reduction and new index of loss exchange in loop network Thus, the proposed algorithm in this paper can search the optimal topological structures of distribution feeders by changing the open/closed states of the sectionalizing and tie switches. The proposed algorithm has been evaluated with the practical IEEE 32, 69 bus test systems and KEPCO 148 bus test system to show favorable performance gained.

• Proceedings of the KIEE Conference
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• 2002.11b
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• pp.265-267
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• 2002

In this paper, the communication between Over-Current Relay agents is realized using DNP(Distributed Network Protocol), which is the standard communication protocol of distribution automation system in KEPKO. The key words in OCR agent communication are defined and represented by use of DNP application function code. And the DNP index for OCR agent is defined. The proposed communication scheme is tested by use of Communication Test Harness, a test tool for DNP protocol to show its soundness.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.16 no.9
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• pp.872-880
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• 2004

The fault detection and diagnosis technology may be applied in order to decrease the energy consumption and the maintenance cost of the air-conditioning system. In this study, an air handling unit fault test apparatus was built and fault diagnosis algorithms were applied to diagnose various faults of an air handling unit. Test results showed the good diagnosis for applied faults. Therefore, these algorithms may be effectively used to develope the real time fault detection and diagnosis system for the air handling unit.

• Journal of Welding and Joining
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• v.32 no.1
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• pp.47-52
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• 2014

Due to of high intensity, lower noise and easy controllability of the heat, induction heating system became well known. Induction heating method has been suggested as substitute for the gas heat source and adopted in the automation of curved hull forming system. In this study, an investigation was accomplished to find the effects on the change of material properties when the induction heating was applied on the mild steel plate. Plates were heated using weaving method to get sufficiently heat affected zone and then cooled with water or in the air. The mechanical properties of the heated plate were evaluated. As results, the tensile test, impact test and microstructures satisfied the class rule.

• International Journal of Contents
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• v.3 no.3
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• pp.32-37
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• 2007

Up to now, several tools to evaluate visual perception tests have been introduced for different purposes. However, they were mostly manual tools, paper books in which the therapists would turn the pages while working together with patients. This paper discusses a potential plan to develop motor-free visual perception test software for Korean patients with brain injury, and to construct a centralized database for their evaluated data in a client/server environment. Through its development, we eventually hope to achieve effective management of the data for better understanding of patients' visual perceptual skills and the standardization of the evaluation for Korean patients. With the help of the computerized environment, we also expect some advantages such as acquisition of reliable results from patients with brain injury, automation for storing and accessing patients' data, construction of the patients' database and the management of a vast amount of the data within it and the provision of a foundation to promote further development of various perceptual-cognitive rehabilitation programs.