• The Journal of Korean Institute of Communications and Information Sciences
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• v.39C no.10
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• pp.930-936
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• 2014

Smart Multiple-Tap to be introduced in this paper, is an electronic device that controls the Multibple-Tap through the Smartphone. It runs on network and has an inbuilt Zigbee communication module. Thus, users can control home devices from remote through home server. Mentioned home server is operated as a gateway and is connected with smart devices on the Internet. To sum up, Users using this Smart Multiple-Tap can check the state information of the multi-tap ON/OFF and can control immediately by smartphone. also, Smart Multiple-Tap perfectly shut down the standby power. when users turn off each of the Smart Multiple-Tap's circle, It drives automatically lowest electricity-consuming mode and shut down the standby power by its own built-in SSR module. therefore, it will bring the energy saving effect on environment using Smart Multiple-Tap.

• KSBB Journal
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• v.23 no.4
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• pp.281-284
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• 2008

A simple and efficient microwave-assisted extraction procedure was developed and optimized for the extraction of paclitaxel from the plant cell cultures of Taxus chinensis. The biomass, immersed in a methanol-water mixture, was irradiated with microwaves in a closed-vessel system. The microwave-assisted extraction was compared with the existing conventional solvent extraction in terms of yield, extraction time, and solvent consumption. The use of microwave energy allows rapid recovery of paclitaxel from biomass and dramatically reduces extraction time and solvent usage compared to conventional solvent extraction. The paclitaxel was completely extracted from biomass by microwave-assisted extraction for 3 min at $50^{\circ}C$, for 6 min at $30^{\circ}C$ and $40^{\circ}C$, respectively.

• Transactions of the Korean Society of Mechanical Engineers
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• v.14 no.1
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• pp.251-258
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• 1990

Optimal design of heat exchanger for closed CO$_{2}$ gas turbine plant of three processes selected from the result of cycle analysis have been discussed previously paper(I) has been carried out under specified inlet and outlet conditions. Independent variables such as number of parallel connection, tube diameter, shell side and tube side pressure loss as well as dependent variables such as shell diameter, number of tubes, number of serial connections were all characterized according to the standardization or so. Search method was used to construct a computer simulation together with the calculation of heat transfer rate by logarithmic mean temperature difference method. Strength analysis of major parts was carried to examine their dimensions satisfying heat transfer and pressure loss requirements.

• Journal of the Korean Institute of Gas
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• v.5 no.4 s.16
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• pp.21-26
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• 2001

Because of the continuous growth of energy consumption, and also tile tendency to site power lines and pipelines along the same routes, the close proximity of high voltage structures and metallic pipelines has become more and more frequent. Recently, the results of assessment about a system integrity are needed in korea also when a gas pipeline is running parallel with high voltage power line in same submarine tunnel, Therefore, we analyze the system integrity(AC corrosion of pipe, melting of pipeline coating, safety of insulation flange, especially cathodic protection system which are rectifier and CI(cathodic Isolator)) resulting from the influence of high voltage power system.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.21 no.3
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• pp.125-131
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• 2007

Electric motor efficient improvement from home appliance field is important to the effect reducing the energy consumption. But the electric motor design/analysis technology is still insufficient. Specially the electric motor design/analysis technology of satisfying characteristic of both the induction motor and the synchronous motor such as Line start permanent motor. Therefore the electric motor design/analysis technology is urgently demanded reliability. This paper proposes the sing1e-phase line-start permanent magnet motor to develop the motor it with be able to alternate the sing-phase induction motor it is a refrigerator compressor motor. The sing-phase induction motor is analyzed in the steady state. And we have a certification test to compare our single-phase line-start permanent magnet motor with the sing-phase induction motor. In order to improve the performance, the stator of the single-phase line-start permanent magnet motor is same as the stator of the sing-phase induction motor and changes the rotor form and has the permanent magnet. It used the Finite Element Method(FEM) which is widely used with electronic-magnetic field numerical analysis method.

• Journal of Korean Society of Environmental Engineers
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• v.38 no.5
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• pp.219-227
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• 2016

As the largest source of food waste is housing, and the food waste properties are good enough to recycle, the proactive approach to conventional food waste disposal is highly regarded. This research is to examine food waste management in the Seoul Metropolitan Area (SMA) and non-SMA and to analyze the public inclination to disseminate zero-food waste system (ZFWS) with fermentation and extinction technology in multifamily housing estates. The self-administered questionnaire survey was conducted and the collected data were statistically analyzed. The main findings are summarized as follows: food waste in multifamily housing estates were retrieved by refuse truck and largely recycled for compost and forage. Also, many local governments were in favor of ZFWS, and unwilling to invest in it due to financial constraint. It's found that logistics of ZFWS is likely to be influenced by important features such as a considerable amount of cost saving, effective energy recovery, and efficient operation/management.

• Journal of Bio-Environment Control
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• v.9 no.4
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• pp.212-222
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• 2000

This study was performed to investigate the performance of heat recovery device attached to exhaust gas flue connected to combustion chamber of greenhouse heating system. The experimental heat recovery system is mainly consisted of LPG combustion chamber and two heat recovery units; unit-A is attached directly to the exhaust gas flue, and unit-B is connected with unit-A. Heat recovery performance was evaluated by estimating total energy amounts by using enthalpy difference between two measurement points together with mass flow rate of gas and/or air passing through each heat recovery unit depending on 5 different flow rates controlled by voltage meter. The results of this experimental study, such as heat exchange behavior of supply air tubes and exhaust air passages crossing the tubes, pressure drop between inlet and outlet, heat recovery performance of exchange unit, etc., will be used as fundamental data for designing optimum heat recovery device to be used for fuel saving purpose by reducing heat loss amounts mostly wasted outside of greenhouse through flue.

• Proceedings of the KIEE Conference
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• 2006.07d
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• pp.2134-2135
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• 2006

전력거래소는 발전경쟁시장(CBP; Cost-Based Pool) 장기화에 따른 운영상의 효율성을 개선하고 기 개발된 시장운영시스템(MOS; Market Operation System)을 활용하여 급전체계를 개선하기 위해 준비중이다. 현행 급전체계에서는 거래 전일에 수행한 수요예측을 바탕으로 1시간 단위운영발전계획을 전일에 수립하고 EMS(Energy Management System)를 이용하여 발전기에 대한 경제부하배분(ED; Economic Dispatch)을 시행하고 있지만, 현 EMS는 시장체제 환경 전에 도입된 설비로 시장환경에 대한 고려가 되어 있지 않고 계통운영 보조서비스의 실시간 반영이 어려운 점이 있다. 전력거래소는 실시간 급전 운영을 위해 기존 EMS에 MOS를 연계하여 MOS의 5분 단위 수요예측량을 기반으로 송전망 제약과 예비력 요구량 등을 고려한 발전기별 경제부하 배분량 및 예비력 배분량을 결정하고, 추가적으로 EMS에서 수요예측 오차 및 주파수 보정량을 실시간으로 계산하여 발전기별로 배분하도록 함으로써, 1일 전 시행하던 급전계획을 취득 자료를 기반으로 5분 단위로 실시간 계산할 수 있도록 급전 체계를 개선할 계획이다. 이를 통해 실시간으로 에너지와 예비력을 동시에 최적화함으로 전력시장 및 전력계통 운영을 한층 선진화 할 수 있는 계기를 마련하였으며 또한 저비용 발전기 사용을 극대화함으로 발전비용의 절감에도 기여하는 효과를 기대할 수 있다. MOS-EMS간 자료연계에는 ICCP(Inter-Control Communication Protocol)와 FTP 프로토콜을 사용하였고, 수차례 모의운영을 통하여 데이터베이스 및 현장 취득 자료의 정확도(accuracy)가 양 시스템 간 연계 및 전력 계통의 안정적 운영에 매우 중요한 요소로 나타났다. 전력거래소는 장기적으로 CIM(Common Information Model)기반의 표준 전력계통 데이터베이스를 구축하고 시스템 간 자료 연계를 위해 XML을 활용하여 시스템 간 상호 운영성(Interoperability)과 자료 연계의 안정성을 높일 계획이다. 본 논문은 MOS-EMS 연계에 따른 시스템 간 자료의 흐름 및 처리에 대해 주로 설명하고자 한다.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.28 no.11
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• pp.421-427
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• 2016

The indoor temperature of a building increases during the day due to solar radiation. This behavior is significant in school buildings that are finished with high thermal capacity materials. Moreover, in school buildings, windows cannot be opened until the class has finished owing to the security policy of schools. Consequently, classrooms maintain a high temperature throughout the morning. It is thus important to remove the indoor heat before the commencement of classes in order to reduce the cooling energy needed. The Energy Recovery Ventilator (ERV) system is currently being installed in school buildings for ventilating the classrooms. Night-purge control using ERV can be a good strategy to cool the classroom in advance of the operation of the cooling system. However, the optimal operation method of the ERV for night-purge control has not yet been reported. In this study, the effect of night-purge control with ERV in school buildings is analyzed by simulation method. The results of this study showed that the energy saving effect of night-purge control with ERV is most effective in the case of 2 hours operation prior to the commencement of the first lass and when enthalpy based outdoor air cooling is used.

• Journal of Convergence Society for SMB
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• v.2 no.1
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• pp.19-24
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• 2012

In this paper, we propose the battery life time extension method in the multi-interface terminal by using the state information in an optical wireless integrated network architecture. When the bottlenecks occurs in the network, the terminal receives data packets via multipath. However, the battery life time is rapidly reduced because the power consumption of the terminal is bigger than single interface. For reducing the power consumption in the multi-interface terminal, the Optical Line Terminal (OLT) confirms whether the bottleneck phenomenon is occurred or not. And the network state information is transmitted to the terminal. The terminal turns one of the interfaces off to reduce the power consumption. In order to estimate the performance, we compare the power consumption between single and dual interfaces.