• The Transactions of The Korean Institute of Electrical Engineers
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• v.56 no.6
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• pp.1031-1034
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• 2007

Electric transmission lines pass through a variety of area. Foundation supporting the conductors and tower are selected properly in accordance with external load, for example dead load, wind load, snow load, construction load etc, and topography and geology condition. Typical types of foundation are as follows: pad foundation for small load and hard soil or rock in mountainous area, pile foundation for medium or large load and soft soil in plain field area. This paper introduced cylindrical foundation design & construction for large load and mountainous area. This foundation failure mode against pulling-out show splitting failure by tensile force toward circumferential direction.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2005.05a
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• pp.217-220
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• 2005

Zero tail type mini excavator is small in size and capacity compared with medium or large excavator. Therefore noise and heat problems are major issues in design due to layout of each components such as engine and hydraulic module. It is necessary to assure reduction of noise and vibration in construction machine, due to be enforced regulation for high noise construction machinery at home and abroad. The objective of this study is to provide basic data which is apply to predict noise effect in detail design stage by estimating noise of cabin for zero tail type mini excavator.

• Journal of Korean Society of Water and Wastewater
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• v.28 no.3
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• pp.305-314
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• 2014

A pilot plant (Q=5 $m^3/d$) study was implemented for small and medium sized personal wastewater treatment plant effluent to evaluate MBR and A/O processes utilizing self-sufficient energy composed of wind and solar energy. The removal efficiencies of BOD, SS, turbidity and color were sufficient for legal water quality standards for gray water. However, those of nitrogen and phosphorus could not meet legal regulations which suggested that further removal of those contaminants were needed for reuse of the treated water. Self-sufficient energy rate was 100 % for the pilot plant due to excessive design capacity. In this research, wind and solar energy system was applied considering geological characteristics, which significantly improved energy self-sufficiency. Substantial improvement on energy self-sufficiency can be obtained by optimized investment and operation at a full scale wastewater treatment plant.

• Proceedings of the Korea Water Resources Association Conference
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• 2006.05a
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• pp.735-739
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• 2006

중 소규모 댐의 경우 대부분 홍수에 취약한 것으로 확인되고 있으나 투자의 우선순위에 밀려 안전의 사각지대에 놓여 있는 것이 현실이다. 그러나 만약 댐이 붕괴될 경우에는 그 피해가 막대하므로 현실적인 대책수립과 함께 보강조치가 필요하다. 본 연구에서는 치수 및 경제적인 측면에서 현실적인 대안을 강구하기 위하여 기존의 중.소규모 댐들을 저수지 규모 및 여수로 형식별로 분석하였고, 홍수배제능력증대사례를 조사하여 중.소규모 댐들에 적용 가능하다고 판단되는 몇 가지의 여수로 개축모형(안)을 선정하였다. 또한 선정된 개축모형(안) 중에서 1차적으로 Labyrinth spillway의 경우에 대한 방류능력증대 효과를 3차원 수치해석을 통하여 검토한 결과 초기방류량의 증가에 따른 홍수조절효과로 개축전의 월류수심 2.40m를 2.05m로 낮출 수 있고 기준 여유고를 확보할 수 있는 것으로 분석되었다.

• Korean Journal of Microbiology
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• v.18 no.3
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• pp.115-122
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• 1980

We have demonstrated that both L-histidine as an amino acid factor and dextrin as a carbon source were required for the glucose repression. 1% glucose was sufficient to the glucose repression of aerial mycelium formation in Streptomyces lavendulae and Streptomyces aureofacience. the synthesized medium, KK, which is lack of all orgnic nutrients except dextrin was able to induce glucose repression, but the addition of 0.003% or more L-histidiner recovers the capacity of glucose repression. 0.02% or more histidine was reuqired for glucose repression of aerial mycelium formation in the absence of dextrin. Treatments of $5{\mu}M$ ormore ethidium bromide (EtBr0 gave rise to bald mutants at high frequency in Streptomyces aureofaciens, and it is probable that the gene(s) for the function of aerial mycelium formation is linked to plasmed DNA in this species.

• 한국정보통신설비학회:학술대회논문집
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• 2007.08a
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• pp.223-226
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• 2007

This paper first outlines the technology used in Power Line Communications(PLC) systems, and the political support being offered to the technology, from the point of view of its effect on electromagnetic compatibility (EMC). The radio spectrum needs protection from other interferers, and there is a regime in place to provide this interference avoidance/mitigation. Nevertheless, PLC has several features that mean that it is capable of creating such interference. These features are discussed, and some published field trial results are reviewed. Difficulties in achieving compatibility between the requirements for radio protection and the requirements for operation of the PLC system mean that there is no consensus as yet as to how PLC system components can be made compliant with EMC requirements. It is concluded that there is little prospect of an accommodation between the competing demands, so that if PLC is to become widespread it will be at the expense of the radio environment.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.1664_1665
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• 2009

Many years ago, most of thermal power plants built in this country were of subcritical pressure, of medium or small size, of constant pressure operations and of drum type steam generators with circulation type boilers. But, nowadays almost all of them were of high efficiency, of supercritical pressure, of big capacity, of sliding pressure operations, and of once through type steam generator. It has such advantage as the reduction of startup duration, but it control system and operation method are very complicated. It has a big difference in operation method of turbine and boiler. The feedforward control needs to be introduced to prevent such problems as thermal shock during the transit from normal operation into bypass operation. This paper introduces the turbine control and turbine bypass control during startup of thermal power plants.

• 한국신재생에너지학회:학술대회논문집
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• 2006.11a
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• pp.561-565
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• 2006

The paper presents a method of assessing the adequate tapaclty of photovoltaic generation systems for public buildings based on analysis of load variation patterns of customers. When PV systems are installed for supplying power for the customer load, reverse power relay is required by the guideline to be installed at the point of common coupling with the power network. The suggested method analyzes daily, weekly and monthly load demand of the customer that Irishes PV system installation, and determines the appropriate rating of the PV system for preventing PV generation from exceeding the customer demand. This work is expected to support renewable energy dissemination projects of public organizations.

• Journal of Electrical Engineering and Technology
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• v.12 no.4
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• pp.1435-1441
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• 2017

Distributed generation (DG) in the future will play an important role in the electricity supply systems, in wich can provide DG capacity from a few hundred kW to tens of MW. However, it is connected to the local power grid, DG will have certain influence on the power quality of the power grid. One of the most significant effects is that they will change the configuration of the local power grid as well as affecting the operation mode of the grid. This paper presents a method of finding the optimal open loop, analyzing and selecting the appropriate mode of operation to reduce power losses of power distribution networks that includes DG.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.07b
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• pp.801-804
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• 2002

Electrochemical capacitors are becoming attractive energy storage systems particularly for applications involving high power requirements such as hybrid systems consisting of batteries and electrochemical capacitors for electric vehicle propulsion. Both of amorphous cobalt oxide and manganese dioxide were prepared by sol-gel process reported in our previous work. Nanostructured supramolecular oligomer of 1,5-diaminoanthraquinone(DAAQ) coated metal oxides were successfully prepared by electrochemical oxidation from an acidic non-aqueous medium. We established process parameters of the technique for the formation of nano-structured materials. Furthermore, improved the capacitive properties of the nano structured metal oxide electrodes using controlled solution chemistry. $CoO_2$ and $MnO_2$-based composite electrode showed relatively good electrochemical behaviors in acidic electrolyte system with respect to specific capacity and scan rate dependency.