• 한국건설관리학회논문집
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• 제12권6호
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• pp.101-109
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• 2011

온실가스 배출로 인한 기후변화가 심각한 문제로 대두되면서, 국내 외에서 건물 에너지 절감을 위한 노력이 전개되고 있다. 특히, 국내 주거용 건축물 사용단계의 에너지 사용에 따른 온실가스 배출량은 전 생애주기에서 매우 큰 비중을 차지하고 있으며, 노후 공동주택의 수가 급격히 증가하고 있는 상황에서 기존 공동주택의 개선을 통한 에너지 절감의 중요성은 더욱 높아지고 있다. 그러나, 기존 공동주택의 개선에 대한 의사결정 과정에서, 에너지 절감에 대한 부분은 주요 고려사항으로 반영되지 못하고 있으며, 이를 반영하기 위해 필요한 의사결정 지원도구 역시 미비한 실정이다. 본 논문은 공동주택 개선여부의사결정 단계에서 활용할 수 있는 의사결정 지원 시스템을 개발하는 첫 단계로서, 유사 특성을 지닌 공동주택 단지간의 군집을 형성하는 분류체계를 구축하고자 했다. 이를 위해 데이터마이닝 기법 중 하나인 의사결정나무를 활용하여 공동주택 단지 특성 및 전력, 가스, 지역난방 에너지 사용량 기반의 군집을 형성했다. 향후 본 연구의 결과를 더욱 발전시켜 공동주택 개선단계에서의 의사결정 시 에너지 사용량을 고려사항으로 반영함으로써, 노후 공동주택 개선을 통한 에너지 절감 및 이산화탄소 배출량 감축 효과를 극대화할 수 있을 것으로 기대된다.

• Journal of Advanced Marine Engineering and Technology
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• 제28권3호
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• pp.516-521
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• 2004

In this paper, the effects of ethanol blended gasoline on emissions and their catalytic conversion efficiencies characteristics were investigated in gasoline engine with an electronic fuel injection. The results showed that the increase of ethanol concentration in the blended fuels brought the reduction of THC and $CO_2$ emissions from the gasoline engine. THC emissions were drastically reduced up to thirty percent. And brake specific fuel consumption was increased. but brake specific energy consumption was similar level. However. unburned ethanol and acetaldehyde emissions increased. The conversion efficiency of Pt/Rh based three-way catalysts and the effect of ethanol on CO and NOx emissions were investigated by the change of engine speed. load and air/fuel ratio. Furthermore, the ethanol blended fuel results in the reduction effect of THC. CO and NOx emissions at idle speed.

• 농업과학연구
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• 제38권3호
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• pp.525-532
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• 2011

The aim of this study was to develop a portable electronic nose system for freshness measurement of meats, which could be an alterative of subjective measurements of human nose and time-consuming measurements of conventional gas chromatograph methods. The portable electronic system was o optimized by comparing the measurement sensitivity and hardware efficiency, such as power consumption and dimension reduction throughout two stages of the prototypes. The electronic nose systems were constructed using an array of four different metal oxide semiconductor sensors. Two different configurations of sensor array with dimension were designed and compared the performance respectively. The final prototype of the system showed much improved performance on saving power consumption and dimension reduction without decrease of measurement sensitivity of pork freshness. The results show the potential of constructing a portable electronic system for the measurement of meat quality with high sensitivity and energy efficiency.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 춘계학술대회 논문집
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• pp.619-626
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• 2011

In this paper, while electric multiple unit is moving on the rail, the content of measuring and analysing electric power consumption is mentioned. In order to measure the electric power consumption, we developed the power record analysis equipment and installed it the inside of the converter and inverter system to record the electric power consumption measured by voltage sensor and current sensor. Moving on the rail, we analysed traction power used up and regenerative power by using the measuring instrument. We expect that the measured and analysed data will offer basic research material to devise a energy reduction plan and introduce a new EMU system with high efficiency.

• 동력기계공학회지
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• 제19권3호
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• pp.29-35
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• 2015

Environmental pollution is produced by consumption of fossil fuel, therefore alternative fuels is interested for development of new energy resources and reduction of exhaust emissions for air pollution prevention. Biofuels are produced from new vegetable oil and animal fat, may be used as fuel without change of engine structure in diesel engine. In this paper, the test results on specific fuel consumption, combustion characteristics of neat diesel oil and biodiesel blends(10 vol.% biodiesel and 20 vol.% biodiesel) were presented using four stroke, direct injection diesel engine, especially this biodiesel was produced from biodiesel fuel at our laboratory by ourselves. This study showed that specific fuel consumption is increased slightly, on the other hand cylinder pressure, rate of pressure rise, rate of heat release and soot were decreased slightly in the case of biodiesel blends than neat diesel oil.

• 한국환경복원기술학회지
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• 제8권6호
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• pp.34-44
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• 2005

The objective of this study is to analyze the thermal properties of various green roof type. The experimental districts, have different soil thickness, soil type, the existence of module and the different kinds of vegetation, had installed. A measurement was conducted in Seoul University to investigate the thermal impacts of rooftop greening. The measurement point of temperature were 30, located in soil surface, middle of the soil layer, under the module, hard surface and soffit surface of each experimental district. The experimental investigation lasted from 6th August to 29th August, a total of 24 days. The results showed that green roof can contribute thermal benefits by soil and vegetation and reduce building energy consumption by a role of insulation. It's also better to make soil thickness over 20cm and various vegetation that should be more effective. The district installed only soil also could be effective for reducing the temperature of roof surface. Therefore, the increase of soil thickness and various vegetation could reduce more temperature of roof surface and building energy consumption. Also, it's helpful to reduce temperature that plant coverage rate be raised.

• 한국지열·수열에너지학회논문집
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• 제11권3호
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• pp.7-12
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• 2015

Currently water supply system with water storage is generally applied except for small building such as single-family houses, and water supply system on replacing water storage installed system by direct connecting system has been increasing because of sanitary and energy-saving aspects. The purpose of this study is to evaluate energy-saving and environmental efficiency of direct connecting booster pump system in comparison with the water storage installed system. The architectural condition of the evaluation subject is ten-story apartment house in which sixty households live. To calculate the power consumption of the pump, the volume of water supply was determined from existing data and other data, such as head, efficiency of the pump, was the value used for general application in design office. The power consumption of the water supply pump for one day was 8.5 kWh for direct connecting booster pump system, and 22.5 kWh for water storage installed system, and the former system showed energy savings of 62% compared to the latter system. Reduced power consumption also leads to reduction of $CO_2$ emission. According to the criteria presented in the Korea Energy Management Corporation, reducing the 2,410 kg $CO_2$ emission is possible per year.

• 에너지공학
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• 제23권2호
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• pp.119-124
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• 2014

1970년대 오일쇼크 이후 많은 국가들이 석유에 대한 에너지 의존도를 줄이는 정책을 펼쳤다. 특히, 한국은 빠른 속도의 탈석유화가 일어났으며, 이러한 탈석유화는 급속한 전기화로 이어져 전력수요 급증의 한 요인이 되었다. 본 연구에서는 OECD 34개국을 대상으로 한 1985년부터 2011년까지의 패널자료를 이용하여 탈석유화와 전기화의 관계를 분석함으로써 최근 벌어지고 있는 전력수급난에 대한 정책적 시사점을 제공하고자 한다. 패널분석을 위해 확률효과모형 및 고정효과모형을 적용하였 다. 분석결과 총에너지 소비에서 에너지유 소비 비중(탈석유화 척도)이 10%p 증가하면 전력 소비량이 약 15% 감소하는 것으로 나타났다. 특히 산업용 전력소비가 전체 전력소비에서 차지하는 비중을 국제 비교해보면 우리나라의 경우 OECD 34개 중 4위(2011년 기준)로 나타나는 등 주로 산업부문에서 석유에서 전력으로의 급격한 수요 전환이 현재의 전력수급 위기의 주요 원인 중 하나라는 점을 알 수 있다.

• 유기물자원화
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• 제20권2호
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• pp.44-52
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• 2012

본 연구에서는 고유가 시대의 대안으로 정부에서 추진하고 있는 농촌형 녹색마을에 재생에너지를 도입하는 경우 $CO_2$ 저감효과를 분석하고, 재생에너지의 보급 활성화 방안을 제시하고자 하였다. 전라북도 G시에 조성하고 있는 소규모 농촌형 녹색마을의 에너지 잠재량을 조사한 결과 태양에너지를 이용하면 연간 6.73 GWh의 전력생산이 가능하고, 바이오매스로는 연간 134.06 GWh의 전략생산이 가능한 것으로 분석되었다. 따라서 전체 전력생산량은 연간 233.19 GWh로서 대상지역에서 연간 사용하고 있는 총 에너지 소비량 705.80 GWh의 33%를 부담할 수 있는 것으로 판단되었다. 한편 이산화탄소 감축잠재량을 산정한 결과 농산부산물은 1,891 ton_$CO_2$, 축산폐기물은 43,635 ton_$CO_2$, 도시폐기물은 395 ton_$CO_2$, 임산부산물은 50,324 ton_$CO_2$로 분석되었으며, 바이오매스로 인한 효과는 연간 총 96,245 ton_$CO_2$ 으로 나타났다. 또한 태양광에너지 2,251 ton_$CO_2$, 태양열에너지 1,383.3 ton_$CO_2$로 태양에너지로 인한 효과는 3,634 ton_$CO_2$이었으며, 총 99,879 ton_$CO_2$의 배출을 감축할 수 있는 것으로 나타났다.

• 전기학회논문지
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• 제64권1호
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• pp.136-142
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• 2015

In the paper, a design method of knee and pelvis joint in the biped robot is proposed for shock absorption and gravity compensation. Similarly to the human's body, the knee joints of the biped robot support most body weight and get a shock from the landing motion of the foot on the floor. The torque of joint motor is also increased sharply to keep the balance of the robot. Knee and pelvis joints with the spring are designed to compensate the gravity force and reduce the contact shock of the robot. To verify the efficiency of the proposed design method, we develope a biped robot with the joint mechanism using springs. At first, we experiment with the developed robot on the static motions such as the bent-knee posture both without load and with load on the flat ground, and the balance posture on the incline plane. The current of knee joint is measured to analyze the impact force and energy consumption of the joint motors. Also, we observe the motor current of knee and pelvis joints for the walking motion of the biped robot. The current responses of joint motors show that the proposed method has an effect on shock reduction and gravity compensation, and improve the energy efficiency of walking motions for the biped robot.