• 한국가스학회지
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• 제13권5호
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• pp.1-6
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• 2009

본 논문에서는 LPG 차량의 연비효과에 미치는 대기온도, 증발기의 가스누출, 엔진오일의 점도, 엔진의 부하조건을 실험적으로 고찰하고자 한다. 연비에 대한 시험결과에 의하면, 엔진의 온도가 상승할수록 연비효과도 함께 점차 높아지고 있다. 대기온도가 $24.2^{\circ}C$일 때의 연비는 $1^{\circ}C$일 때보다 13.6% 정도 높게 나타난 것을 알 수 있다. LP가스 누출이 없는 증발기의 연비는 가스누출이 있는 경우에 비해 5.3%나 좋아지는 것으로 확인되었다. 반면에 엔진오일을 새로 교환한 경우의 연비는 9,500km를 주행한 오일에 비해 1.1% 정도 향상된 것으로 나타났으며, 이것은 대기온도나 증발기의 누설조건에 비해 상대적으로 낮은 영향을 미치는 것으로 관찰되었다. 연비에 더 많은 영향을 미치는 요소는 급제동, 급출발, 급가속과 같은 운전조건으로 판단된다. 연비시험 결과에 의하면, 정상출발은 급출발에 비해 32.3%나 연비가 향상되었고, 급가속은 급출발보다 10.8%나 우수한 연비조건을 보여주고 있다. 또한, 급제동은 급출발보다 18.3%나 우수한 연비상태를 나타내고 있다. 결국 비정상적인 주행조건은 정상적인 운전패턴에 비해 연비가 나쁜 것으로 나타났으므로, 연비를 높이기 위해서는 차량의 주행조건을 정상상태로 유지하는 것이 대단히 중요함을 알 수 있다.

• 한국지열·수열에너지학회논문집
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• 제3권2호
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• pp.25-30
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• 2007

The final energy consumption in the building sector in Korea represents almost 20% of the total energy consumption. Besides, Space heating and hot water generation in Korea are based on fossil fuels, with a serious environmental impact. This study describes thermal performance of heating demonstration system using close-loop ground source heat pump installed at Korean minjok leadership academy. The results of the experimental study, it retrieve the investment cost for 3years 8months and reduction amount of $CO_2$are 293,900 $kgCO_2$.

• International Journal of Advanced Culture Technology
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• 제2권2호
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• pp.19-24
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• 2014

Many people all over the world have been conducting a great deal of research to solve the problem of global warming since the great majority consider reduction of CO2 as the only solution for that. That is why the production and conservation of energy is thought to be highly crucial. while it is important to produce energy with the high efficiency, the efficient use of the energy is also important. This paper focused on the development of devices for the reducing electricity which is a primary energy source used in homes, shops, buildings, factories and so on. Also the objective of this paper is to develop the inference mechanism as the core component of the devices. Therefore, in this paper, we propose the inference algorithm for reducing the electricity consumption using SARIMA mode and present the feasibility of the procedure.

• 펄프종이기술
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• 제35권3호
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• pp.29-36
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• 2003

Reducing the energy consumption while maintaining pulp quality is an important objective of today's paper industry. Enzymatic treatment of fibers and the application of dry strength agent were investigated as methods to reduce energy consumption during refining and to upgrade fiber characteristics. Modification of recycled fibers with an enzyme was effective in improving relining efficiency and reducing refining energy. Optimization of dry strength agent application conditions including stock pH, cationic demand, zeta potential, etc. were found to be very important for improving its effectiveness.

• 한국태양에너지학회 논문집
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• 제32권1호
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• pp.56-66
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• 2012

This study evaluated the economic benefits by comparing Cooling-Heating System with the existing system in the public library. The building's annual energy consumption was measured by adding the figures of the absorber chillers, the air conditioners and heaters in the building. The total amount of annual energy consumption was 143.51RT in air-conditioning and 83.66RT in heating. So, We made the capacity of geothermal heat pumps three 50RTs in order to check up this system. In order to estimate each construction and equipment cost and to evaluate economical efficiency, LCC(Life Cycle Cost) method was used and the service life of the building was sixty years. The result of analysis was that the geothermal cooling-heating system was more efficient than the existing system in public library.

• International journal of advanced smart convergence
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• 제7권4호
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• pp.19-26
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• 2018

One of the distinct features of Wireless Sensor Networks (WSNs) is duty cycling mechanism, which is used to conserve energy and extend the network lifetime. Large duty cycle interval introduces lower energy consumption, meanwhile longer end-to-end (E2E) delay. In this paper, we introduce an energy consumption minimization problem for duty-cycled WSNs. We have applied Q-learning algorithm to obtain the maximum duty cycle interval which supports various delay requirements and given Delay Success ratio (DSR) i.e. the required probability of packets arriving at the sink before given delay bound. Our approach only requires sink to compute Q-leaning which makes it practical to implement. Nodes in the different group have the different duty cycle interval in our proposed method and nodes don't need to know the information of the neighboring node. Performance metrics show that our proposed scheme outperforms existing algorithms in terms of energy efficiency while assuring the required delay bound and DSR.

• KIEAE Journal
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• 제12권4호
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• pp.105-110
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• 2012

Recently, all of the world are facing with a serious environmental crisis of global warming due to excessive energy consumptions. The Korean Government, taking over 97% of dependence on foreign energy, has made various efforts on reducing energy and greenhouse gas emission under the motto of "Low-Carbon Green Growth". Since the building sector takes 24% of domestic energy consumption, many design standards and regulations on saving energy in new buildings have been established. However, applications of energy saving designs and techniques on the remodeling process at deteriorated buildings including educational ones have been lack. Under a situation where the number of deteriorated schools accounts for up to 50%, this paper evaluated the performances of factors for reducing energy at deteriorated middle school buildings through an energy simulation tool on a standard school model. As a result, among factors of insulation, window's SHGC, southern louver, indoor setup temperature, and system efficiency, all other factors except window's SHGC and southern louver proved contribute to reduce energy at deteriorated middle school buildings, compared with the baseline energy consumption.

• 한국농업기계학회:학술대회논문집
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• 한국농업기계학회 1993년도 Proceedings of International Conference for Agricultural Machinery and Process Engineering
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• pp.453-472
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• 1993

Two types of solar energy-latent heat storage system have been developed to minimize the fossil fuel consumption and maximize the solar energy utilization in greenhouse heating during the winter season. The one was installed on the greenhouse floor, and the other in the underground of the greenhouse . Sodium suphate decahydrate was selected as a highly concentrative solar energy storage medium and its unstable thermophysicla properties were adjusted by some additives. Thermal efficiency of them was analyzed by numerical and experimental method.

• 대한환경공학회지
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• 제32권12호
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• pp.1119-1125
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• 2010

하수 슬러지의 혐기성 소화성을 향상시키기 위한 다양한 전처리 방법이 제시되어 있지만, 대부분 낮은 경제성 등의 문제로 현장 적용에 제한을 받고 있다. 본 연구는 장치의 구성 및 유지관리가 용이한 수리동력학적 캐비테이션 방법을 이용한 venturi cavitation system (VCS)의 전처리 효율을 향상시키기 위한 최적 설계 및 운전조건을 도출하기 위하여 수행하였다. VCS에서 벤츄리의 직렬 연결 개수는 3개일 때 가장 높은 전처리 효율을 나타내었고, 펌프는 흡입방식이 압송방식에 비하여 단위 에너지 투입량 당 1.6배 높은 전처리 효율을 나타내었다. 캐비테이션이 발생하는 조건에서 벤츄리의 목 직경 조합은 전처리 효율에 영향을 주지 않았다. 또한 3개의 벤츄리가 직렬로 연결된 벤츄리를 병렬로 설치할 경우 에너지 투입량 당 전처리 효율이 30% 향상되었다. 병렬 연결 운전조건으로 슬러지를 처리하였을 때, 에너지 소모량 당 가용화 효율은 5.6 mg ${\Delta}SCOD/g$ TS/kWh로 기존의 수리동력학적 전처리장치보다 우수하였다.

• 펄프종이기술
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• 제47권5호
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• pp.98-103
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• 2015

The reduction of the energy consumption in papermaking process become more important issue because of the regulation of green house gas (GHG) emission. Since more than half of energy for papermaking process is consumed during drying process, the increase of the drying efficiency would be very important solution for saving energy and reduction of GHG emission. The improvement of drying efficiency could be very difficult for the liner board mill because the liner board are usually made of recycled paper, OCC (old corrugated container). The short fiber and fines originated the OCC lead to compact sheet structure and delay the water flow out during wet pressing process and drying process. The application of lignocellulose spacer could provide more loose wet sheet structure and result in the higher drainage rate and the improved drying efficiency. In this study, the effects of the application of lignocellulose spacer to the liner board mill were evaluated based on the mill trial. In order to overcome the common disadvantage of the spacer, the loss of strength properties, the spacer was pretreated with amphoteric polyelectrolyte during mill trial. The results showed the application of pretreated spacer improved the drying efficiency by reducing steam consumption. And the loss in the strength properties by the spacer could be supplemented by the pretreatment.