• 한국수소및신에너지학회논문집
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• 제30권1호
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• pp.83-94
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• 2019

LPG is increasingly being used as a clean energy source due to the continuous strengthening of environmental regulations. In addition, the demand of propane which is the basic compound for petrochemicals is increasing for propylene production. In the study, a divided wall column was used as de-propanizer and de-butanizer, which is expected to save large amount of energy among the four conventional distillation columns used for processing LPG. The simulation results showed a decrease of energy duty with ESI by 30.30% using two divided wall columns. Furthermore, simulation case studies were carried out with respect to design and operation condition. The main column tray and withdrawal tray were determined from the design case studies while the internal liquid flow and vapor flow were decided from the operating case studies. Also, ESI of 1.06% could be achieved from the case studies. According to the results, the simulation method used showed that it is greatly helpful to the design and evaluate a highly efficient divided wall column.

• 설비공학논문집
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• 제29권10호
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• pp.504-514
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• 2017

The insulation performance of aircaps has been recognized and various studies regarding the aircap as a solution to increased building energy consumption are being carried out. However, the aircap is not durable and therefore it cannot play the role of an independent finishing material. Accordingly, the purpose of this study is to suggest an aircap wall module with improved durability through the lamination of the aircap and verify its effectiveness by evaluating its energy saving performance for lighting and air conditioning through a full-scale testbed. The conclusions of this study are as follows. 1) The aircap wall module featuring a laminated aircap that is being proposed in this study can save lighting energy due to the permeability of the aircap in comparison to previous insulating materials. 2) The aircap wall module with a laminated aircap is effective in improving heating and air-conditioning energy saving when it is more than 15 cm-thick during summer and winter in comparison to a 5 cm-thick prefabricated panel. 3) The aircap wall module featuring a laminated aircap is effective in improving lighting and heating and air-conditioning energy saving when it is 10 cm- and 5 cm-thick during summer and winter, respectively, in comparison to a 5 cm-thick prefabricated panel.

• Journal of Information Processing Systems
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• 제16권2호
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• pp.460-477
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• 2020

As one of the most significant challenges in the virtual data center, the virtual data center embedding has attracted extensive attention from researchers. The existing research works mainly focus on how to design algorithms to increase operating revenue. However, they ignore the energy consumption issue of the physical data center in virtual data center embedding. In this paper, we focus on studying the energy-aware virtual data center embedding problem. Specifically, we first propose an energy consumption model. It includes the energy consumption models of the virtual machine node and the virtual switch node, aiming to quantitatively measure the energy consumption in virtual data center embedding. Based on such a model, we propose two algorithms regarding virtual data center embedding: one is heuristic, and the other is based on particle swarm optimization. The second algorithm provides a better solution to virtual data center embedding by leveraging the evolution process of particle swarm optimization. Finally, experiment results show that our proposed algorithms can effectively save energy while guaranteeing the embedding success rate.

• 설비공학논문집
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• 제16권10호
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• pp.969-976
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• 2004

Building energy saving is one of the most important issues in these days. Energy saving control strategies should be developed properly to achieve the saving. One of such area we could apply is the HVAC (Heating, Ventilation and Air-Conditioning) system. Through the optimal control algorithm for building energy management system (EMS), you can not only save the cost of building energy, but also protect HVAC system components against the unexpected condition. In order to verify the effectiveness of building energy saving, field test was accomplished for several months at 'A' building. And to get the measured data, remote control was used. If the remote control is used in BAS (Building Automation System), control and monitoring can be done for all of the building systems, such as HVAC, power, lighting, security and fire-alarm etc. anywhere any time. Using the remote control, Control and monitoring is possible for the testing system without going there. As the results of field test, we could reduce $5{\sim}10\%$ of the building energy cost.

• 한국실내디자인학회논문집
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• 제20권5호
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• pp.3-12
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• 2011

The purpose of this study is to analyze the sustainable characteristics of London city hall designed by Norman Foster. The most important part of sustainable architecture might be the energy reduction including minimizing CO$_2$ emission but social and economical aspects of sustainability should not be neglected. London City Hall as a successful example of sustainable architecture depends its success on the harmony of social, environmental and economical aspects of sustainability. Social sustainability in London City Hall appears on appropriateness and public good in the facility. London City Hall act as a symbol of redevelopment and civic community. Environmental sustainability of London City Hall summarized as using unique building form, double skin and underground water cooling system for the purpose of energy saving. Computer modeling technology was introduced to save construction cost for economic aspect of sustainability. Rational configuration of mechanical system strengthen the durability of facility. In case of London City Hall, the function of building, site condition and architectural concept fulfill the every aspects of sustainability in architecture. Besides these conditions, Foster applied sustainability to London City Hall as active and concrete design concept to complete its design goals.

• 에너지공학
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• 제22권2호
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• pp.83-89
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• 2013

에너지사용은 우리생활과 밀접한 관계성을 유지하고 있다. 사계절이 뚜렷한 우리나라로서는 건물분야에 냉,난방이 필수품처럼 여겨지는 세대에 살고있어 에너지 사용과 유지에 새로운 트렌드를 요구하고 있다. 이에따라 정부는 신축 및 기존건축물의 에너지효율 개선을 위해서 단열기준을 지속적으로 강화하여 에너지절감을 꾀하고 있다. 공동주택의 에너지효율 분석중 가장 중요한 요소가 열관류율이며 그값은 외피면적비에 대한 창면적비에 따라 난방에너지 요구량이 큰차이를 보여주고 있다. 그러므로 지속적인 효율개선 정책과 외피면적에 대한 창면적비의 규제가 필요한 시점이라 생각한다.

• 한국태양에너지학회 논문집
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• 제33권6호
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• pp.54-61
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• 2013

This is study on the glazing performance of the apartment house to predict energy saving rate when the early design stage by calculating heating load. there are various factors of the window type in apartment building to save energy such as window's U-value, SC or SHGC, window wall ration, frame factor, sunshade coefficient and so on. In this study, we analyzed the heating load focused on the U-value, SC and window wall ration using variable heating degree days method for a small and middle size units $59m^2$, $84m^2$, respectively. Each cases were calculated heating load of the real models compared to standard model to predict energy saving rate. From those cases it was drew the conclusion that were window's U-value, SC and window wall ration for the small and middle size units to expect 10% energy saving rate at least.

• 한국태양에너지학회:학술대회논문집
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• 한국태양에너지학회 2012년도 춘계학술발표대회 논문집
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• pp.331-336
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• 2012

Nowaday the conventional solar collector material prices are rising up because of pricy metal material over the world. The solar collector is too expensive to recycle to save the earth. Advanced polymer research is founded a high thermal resistant polymer and also it has high sun energy transmission. It also has cheaper material and easy manufacturing process, compare with conventional solar collector material. This paper is focussing on glazing simulation of polymer solar collector against wind pressure. The modeling geometry of polymer solar glazing are purposed by single layer, double layer hollow, zig-zag and tower. A simulation by using the Finite Volume was conducted to get Factor of Safety (FoS). The purpose of this paper is to find the best polymer glazing design, which can be as reference for the solar collector company to build Polymer. Hope fully new model of polymer solar collector has cheap, light, high sun energy transmitter, easy to be made and strong against wind force characteristics.

• 한국통신학회논문지
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• 제31권4A호
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• pp.393-401
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• 2006

배터리로 동작하는 휴대용 임베디드 시스템에서 에너지 소모는 중요한 설계 파라미터이며, 동적 전력 관리는 잘 알려진 저전력 설계 기법중의 하나이다. 본 논문에서는 실시간 시스템에서 에너지를 고려한 태스크 스케줄링 알고리듬을 제안한다. 제안한 스케줄링 알고리듬은 시스템에 여유 시간이 존재할 경우 장치 중첩도가 높은 태스크가 우선적으로 수행되도록 스케줄링 하여 장치의 전력 상태 전환 횟수를 줄여준다. 전력 상태 전환 횟수가 줄어들 경우 상태 전환에 따른 전력 소모가 감소하고, 동적 전력 관리의 기회를 더욱 얻을 수 있다. 실험 결과 EDF 알고리듬으로 동작 하는 시스템에서 동적 전력 관리를 한 경우와 비교하였을 때 에너지 소모가 약 23% 감소하였다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제15권1호
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• pp.114-130
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• 2021

With the drastic growth of Information and Communication Technology (ICT) industry, global energy consumption is exponentially increased by mobile communications. The huge energy consumption and increased environmental awareness have triggered great interests on the research of dynamic distribution of cell user and traffic, and then designing the energy efficient cellular network. In this paper, we explore the temporal and spatial characteristics of human mobility and traffic distribution using real data set. The analysis results of cell traffic illustrate the tidal effect in temporal and spatial dimensions and obvious periodic characteristics which can be used to design Base Station (BS) dynamic with sleeping or shut-down strategy. At the same time, we designed a new Cell Zooming and BS cooperation mode. Through simulation experiments, we found that running in this mode can save about 35% of energy consumption and guarantee the required quality of service.