• Journal of the Korean Society for Precision Engineering
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• v.14 no.1
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• pp.84-89
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• 1997

Recentely, a compact and small size air-cleaning Electrostatic Precipitator(ESP) is needed to develop for air conditioning devices. From Deutsch formula for ESP efficiency, collection efficiency is affected not only the structure of collection section but also the charge rate of dust. In terms of collection area, the most useful type is a scroll type ESP. In this work, we investigated experimentally aptimum design factor of scroll type ESP by application of Taguchi method. And we developed the scroll type ESP by using optimal condition of control factor.

• Journal of Korea Multimedia Society
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• v.9 no.12
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• pp.1617-1627
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• 2006

The concept of middleware for digital TV receivers is not new one. Using middleware for digital TV development has a number of advantages. It makes it easier for manufacturers to hide differences in the underlying hardware. It also offers a standard platform for application developers. Digital TV middleware enables set-top boxes(STBs) to run video, audio, and applications. The main concern of digital TV middleware is now to reduce its memory usage because most STBs in the market are small footprint. In this paper, we propose several ideas about how to reduce the required memory size on the runtime area of DTV middleware using a new native process technology. Our proposed system has two components; the Efficient Native Process Module, and Enhanced Native Interface APIs for concurrent native modules. With our approach, the required memory reduced from 50% up to 75% compared with the traditional approach. It can be suitable for low end STBs of very low hardware limitation.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.21 no.4
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• pp.53-60
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• 2007

In this study, an experiment on the efficient construction method of plate electrodes, the influence of electric potential interference in plate electrodes, and building foundations were explored. The experimental result of the electric potential measurement was taken on the basis of the direction of movement and the condition in which the plate electrodes are laid underground in building foundations. It shows that the construction method of laying the plate electrodes vertically exhibits a more efficient reduction of electric potential in a diagonal direction and on an X axis than laying plates horizontally. For plate electrode construction in an area that has uniform conditions, the parallel joint construction method is more effective than a single construction to reduce earth electrical potential and ground resistance. In addition, a straight arrangement performs well in ground efficiency, compared to the parallel arrangement.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2013.10a
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• pp.887-888
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• 2013

본 논문에서는 엘리베이터에서 발생할 수 있는 다양한 고장 요소들을 실시간으로 진단하고 일정시간 이상 운행이 정지된 경우 고장으로 판단하여 운행상태를 CAN 통신을 이용하여 원격으로 모니터링이 가능한 시스템을 설계하였다. 엘리베이터 내의 승객 탑승여부 확인, 현재 운행위치, 주요 고장내용을 실시간으로 진단하고 CAN 메시지를 이용 메인 컨트롤러에 송신하고 엔지니어는 서버기반의 어플리케이션을 통해 확인이 가능하도록 하였다. 또한 자동차, 선박 등 전장분야에 적용되고 있는 CAN 프로토콜을 이용하여 통신의 신뢰성을 확보하고 엘리베이터 관련 운행 및 고장 상태 등을 실시간을 파악할 수 있도록 하여 효율적인 엘리베이터 유지보수를 가능하도록 하였다. 설계된 시스템의 성능평가는 시뮬레이션 및 프로토콜 모니터링을 통해 수행하였다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2007.06a
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• pp.917-920
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• 2007

In this research, a typhoon model has been reproduced on the Masan area which had a great damage caused by a tidal wave of the typhoon "MAEMI" at that time. In addition, after calculating the highest level of a tide that happens in the case, it can be compared with one in a real situation, and the accuracy of the typhoon model could be analyzed as well by comparing the actual overflow area with the greatest overflow area computed by the data of the highest level of a tide. This research is to provide some fundamental and primary materials for the design of stable harbor structure by predicting such as tidal changes that follow some typhoon matrixes hereafter.

• Journal of the Korean Society of Industry Convergence
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• v.24 no.6_1
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• pp.683-691
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• 2021

Bipolar plates with channel width of 0.5 mm, 0.4 mm, and 0.3 mm respectively were printed using a 3D printer. The shape of three b ipolar plates was rectangular, the channel depth was 0.5 mm, and the thickness of base was 0.5 mm. The bipolar plate with channel width of 0.5 mm had 45 channels, and their active area was 44.5 mm × 50 mm. The bipolar plate with channel width of 0.4 mm had 57 channels and its active area was 45.2 mm × 50 mm, and the bipolar plate with channel width of 0.3 mm had 75 channels and its active area was 44.7 mm × 50 mm. The bipolar plates were printed using PLA filament. The cross-sectional lengths of the bipolar plates with channel widths of 0.5 mm and 0.4 mm were identical by 96% of the designed cross-sectional length. Whereas the bipolar plate with a channel length of 0.3 mm had a large difference of 25% from the designed cross-sectional length.

• Journal of the Korean Society of Food Culture
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• v.17 no.3
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• pp.225-239
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• 2002

This is the research on the observing annual customs, the annual custom foods and the application of the annual custom foods to the school foodservice. We sample 419 housewives live in Kyungnam area and 174 dieticians work at the primary and secondary schools. Annual customs the housewives and dieticians observe at high degree are Chuseok, Seolral, Jeongwoldaeboreum, Dongji, Chopail, Sambok etc. The housewives observe more Seolral, Chuseok and Dongji than the dieticians and the dieticians observe more Sambok than the housewives.(P<.001) When they provide school foodservice, the dieticians observe Dongji at the highest degree. In Kyungnam they eat most the gakjongnamul as annual custom foods on Chuseok and Seolral. They eat most ogokbap and mugeunnamul on Jeongwoldaeboreum, minarinamul on Chopail, and samgyetang on Sambok and patjuk on Dongji as the annual custom foods. Most of dieticians (94.3%) answer that it is good to provide annual custom foods as the school foodservice on annual customs. However, they indicate some practical problems to do such as inadequacy of the school cooking facilities, its not suiting students' tastes, etc. The rate of housewives' answers that we have to transmit annual customs is higher than that of dieticians.(P<.001) Seolral topped the list of annual customs both housewives and dieticians answer must be transmitted, followed by Chuseok, Jeongwoldaeboreum, Dongji. Dongji is followed by Chopail(P<.001) in the housewives' answers while Sambok(P<.001) in the dieticians' answers. Though most of the respondents know the origins, dates and details of annual customs they think must be transmitted, they don't know well those of the other ones. By their mothers both housewives and dieticians have come to know about annual customs and mostly affected. Secondly housewives affected by their mothers-in-law while dieticians by their school education.(P<.001)

• Journal of the Korean Society of Industry Convergence
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• v.25 no.4_2
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• pp.699-706
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• 2022

In this study, Directed energy deposition (DED) among additive manufacturing is applied to repair damaged spindle key parts of planner miller. The material of the spindle key is SCM415, and the P21 Powder is used. In order to find the optimal deposition conditions for DED equipment, a single-line deposition experiment is conducted to analysis five parameters. The laser power affects the width, and the height is a parameter affected by coaxial gas and powder gas. In addition, laser power, powder feed rate, coaxial gas, and powder gas are parameters that affect dilution. Otimal deposition is that 400 W of laser power, 4.0 g/min of powder feed rate, 6.5 L/min of coaxial gas, 3.0 L/min of powder gas and 4.5 L/min of shield gas. By setting the optimum conditions, a uniform deposition cross section in the form of an ellipse can be obtained. Damage recovery process of spindle key consists of 3D shape design of the base and deposition parts, deposition path creation and deposition process, and post-processing. The hardness of deposited area with P21 powder on the SCM415 spindle key is 336 HV for the surface of the deposition, 260 HV for the boundary area, and 165 HV for the base material.

• Journal of Electrical Engineering and Technology
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• v.10 no.1
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• pp.288-294
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• 2015

Recently, the module-integrated converter has shown an interest in the photovoltaic generation system. In this system, the high frequency transformer should be compact and efficient. The proposed method is based on the correlation characteristic between the copper and core loss to minimize the loss of transformer. By sizing an effective cross-sectional area and window area of core, the amount of loss is minimized. This paper presents the design and analysis of high frequency transformer by using the 3D finite element model coupled with DC-DC converter circuit for more accurate analysis by considering the nonlinear voltage and current waveforms in converter circuit. The current waveform in each winding is realized by using the ideal DC voltage source and switching component. And, the thermal analysis is performed to satisfy the electrical and thermal design criteria.

• Journal of Korean Library and Information Science Society
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• v.33 no.4
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• pp.241-259
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• 2002

This paper is a study on the current statues of the shared acquisition system of occidental journals in 6 university libraries belonging to Pusan-Kyungnam Area University Information Cooperation Council. The study discusses theoretical background of a shared acquisition in general and historical development and analyzes the current status of the system. Also the study examines the usefulness. effectiveness and problems of the system.