• NEWSLETTER 전기공업
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• no.97-11 s.180
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• pp.8-13
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• 1997

• Journal of Power System Engineering
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• v.17 no.6
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• pp.79-87
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• 2013

The improvement of cooling efficiency for the cabinet of automatic controller is the most efficient method of it's application. Therefore, this study has been analyzed and investigated the improvement of cooling efficiency and reduction of energy for the cabinet of automatic controller, respectively. So this study was conducted to enhancement of cooling efficiency for the cabinet of automatic controller by making a structure which produces difference of air pressures in the entrance tube of external air. And the structure has capacity of the pyrogen source (PTC elements) to make temperature range from $145^{\circ}C$ to $155^{\circ}C$. Consequently, temperatures of the upper, the lower in the interior of the cabinet of automatic controller and the exhaust part were revealed $28.57^{\circ}C$, $23.38^{\circ}C$and $36.14^{\circ}C$(average temperature of the exhaust part in case of existing method : $45^{\circ}C$) in target test of this study, respectively. It was found that the cabinet of the automatic controller has better cooling ability than the cabinet of automatic controller by using an existing method.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.5 no.3
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• pp.503-516
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• 2001

At present, environmental control system of greenhouses related with industrial automation in the korea is composed of on/off-type control machine using a timer in facilities requiring intensive labor. This system, however, makes it difficult for us to find out any status of environmental control system in greenhouses when we are situated in a remote area or at midnight. In this paper we improved a system to monitor status for manual and automatic control by means of PC by replacing an existing on/off-type controller with a display panel, It also attempts to implement DB for information on corps and to provide a user with the efficiency of getting information for plants.

• Proceedings of the KIEE Conference
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• 2007.04c
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• pp.24-28
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• 2007

공장 내에서 부적절한 배선 및 설치 등에 의하여 검사과정을 수행할 경우 noise나 오결선을 유발시키며, 이는 측정해야할 신호가 부적절한 동작을 발생시키거나 검사가 되어 출하 후에 하지 않아도 될 A/S 지원을 해야 하는 등의 추가 경비가 소요되는 문제까지도 야기시킬 수 있다. 이때, 사용자측에서 발생될 불만에 따른 회사 및 제품의 신뢰도 저하는 더 큰 문제가 아닐 수 없다. 본 개발에서는 GUI(Graphic User Interface) 환경과 통신기술을 접목하여 다양한 제품의 검사를 위한 시스템을 개발하고자 한다.

• Journal of the Korean Society of Radiology
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• v.5 no.6
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• pp.421-426
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• 2011

This research was accomplished to assess dose effects on image quality at computed radiography (CR). The ultimate target of the research was finding optimized exposure that provides necessary image quality for the clinical chest diagnosis. Modulation transfer function (MTF), normalized noise power spectrum (NNPS), and Noise equivalent quanta (NEQ) corresponding to the different doses were measured for the assessment of image quality. The preparation of "edge test device" used in MTF measurement and experimental geometry setup were followed by the recommendations of International Electrotechnical Commission (IEC). The experimental results show the necessary image quality can be achieved even at a half of the automatic exposure control (AEC) setting dose for chest diagnosis. It means that the patient exposure can be reduced dramatically by using optimized dose.

• Journal of Advanced Navigation Technology
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• v.21 no.4
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• pp.413-421
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• 2017

In this paper, we designed and fabricated a compact UHF receive module for efficient operation such as tactical and operation situation, target location information confirmation, target reset using Link-K(Korean joint tactical data link system). And the effect of target reset was analyzed by simulation. The designed module consists of UHF(ultra high frequency) receiver section, control section, and power distribution section. The UHF receiver section performs frequency down conversion, filtering and automatic gain control, etc. The control section demodulates frequency down-converted signals, extracts information, and performs external interworking. The power distribution section supplies external power, generates and supplies the power required by each section. The fabricated module was dimension of $105{\times}105{\times}80mm$ and weighed 1.10 kg and The receiving distance is more than 50 km.

• Journal of the Korean Institute of Gas
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• v.16 no.4
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• pp.52-58
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• 2012

Recently, waste gas incineration is increasing due to strong environmental regulatory system in Korea. These incinerating facilities are usually connected with the top of the storage tank through pipeline and incinerate off gas with the flame. Therefore, the flame originated from these facilities is likely to move back into pipeline and might cause an explosion of the storage tank. Accordingly, the purpose of this study is to suggest the preventive measures and the way to improve the safety of these incineration systems through the cause analysis of a major industrial accident occurred in a acrylic acid manufacturing process in Korea. As a result of the study, the preventive measures are suggested as follows. (1) Air or inert gas inflow facilities should be well designed to dilute flammable gases into air or inert gas sufficiently before the blower is restarted in order to prevent the explosion (2) It is needed for the detonation-type flame arresters to be installed on the top of the storage tanks. (3) In case of using the deflagration-type flame arresters, it is necessary to install a rupture disk before the arresters, or blow off the flame outside tanks by connecting the tank top and the incinerator with hood-type pipe. (4) TDR should be installed to be restarted automatically after the momentary power failure.

• Journal of Bio-Environment Control
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• v.26 no.4
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• pp.353-360
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• 2017

In this study, the design and performance test of the air to water heat pump capable of producing hot water for greenhouse heating by using the surplus solar heat inside the greenhouse and the air heat outside greenhouse as the selective heat source were conducted. The heat storage operations using the surplus solar heat and the outside air heat were designed to be switched according to the setting temperature of the greenhouse in consideration of the optimum temperature range of the crop. In the developed system, it was possible to automatically control the switching of heat storage operation, heating and ventilation by setting 12 reference temperatures on the control panel. In the selective heat storage operation with the surplus solar heat and outside air heat, the temperature of thermal storage tank was controlled variably from $35^{\circ}C$ to $52^{\circ}C$ according to the heat storage rate and heating load. The heat storage operation times using the surplus solar heat and outside air heat were 23.1% and 30.7% of the experimental time respectively and the heat pump pause time was 46.2%. COP(coefficient of performance) of the heat pump of the heat storage operation using the surplus solar heat and outside air heat were 3.83 and 2.77 respectively and was 3.24 for whole selective heat storage operation. For the comparative experiment, the heat storage operation using the outside air heat only was performed under the condition that the temperature of the thermal storage tank was controlled constantly from 50 to $52^{\circ}C$, and COP was analyzed to be 2.33. As a result, it was confirmed that the COP of the heat storage operation using the surplus solar heat and outside air heat as selective heat source and the variable temperature control of the thermal storage tank was 39% higher than that of the general heat storage operation using the outside air heat only and the constant temperature control of the thermal storage tank.