• 한국IT서비스학회지
• /
• 제12권4호
• /
• pp.369-380
• /
• 2013

The advent of the state-of-the-art technologies such as cloud computing and big data processing stimulates the provision of various new IT services, which implies that more servers are required to support them. However, the need for more servers will lead to more energy consumption and the efficient use of energy in the computing environment will become more important. The next generation nonvolatile RAM has many desirable features such as byte addressability, low access latency, high density and low energy consumption. There are many approaches to adopt them especially in the area of the file system involving storage devices, but their focus lies on the improvement of system performance, not on energy reduction. This paper suggests a novel approach for energy reduction in which the MRAM-based SSD is utilized as a storage device instead of the hard disk and a downsized page is adopted instead of the 4KB page that is the size of a page in the ordinary file system. The simulation results show that energy efficiency of a new approach is very effective in case of accessing the small number of bytes and is improved up to 128 times better than that of NAND Flash memory.

• 한국정보통신설비학회:학술대회논문집
• /
• 한국정보통신설비학회 2009년도 정보통신설비 학술대회
• /
• pp.349-352
• /
• 2009

WBAN/USN systems are applied from the various environment. Therefore, it is coming to be important efficient use power and communication method. The present paper materialize Slave node system which get power from light energy. Also, it materialize Wake-up module and self-power-off circuit which use S-R Flip Flop for efficient using power. This system can be efficient using power at Slave node system. Also, it can be possible application of Self sustaining system by performance verification Wake-up module which determine system "on" without power and Self-power-off circuit.

• 한국통신학회논문지
• /
• 제38A권6호
• /
• pp.528-534
• /
• 2013

센서 네트워크에서 기본적으로 고려되어야 하는 것은 센서 노드의 에너지 소모 문제이다. 이를 해결하기 위해 많은 연구들이 진행되어 왔지만 에너지 소모 문제와 더불어 트레이드오프 관계를 갖는 지연 문제도 간과할 수 없는 부분이다. 본 논문은 생체시스템을 모방하여 무선 센서망에서 에너지의 소모와 지연시간을 줄이기 위한 BISA(Bio-inspired Scheduling Algorithm)를 제안한다. BISA는 에너지 효율성이 높은 라우팅 경로를 탐색하고 다중채널을 이용하여 데이터 전송의 경로를 다중화하여 데이터 전송을 위한 에너지 소모와 지연시간을 최소화한다. 모의실험을 통해 제안한 방식이 효율적으로 에너지를 소모함과 동시에 요구지연시간을 보장함을 확인한다.

• 한국태양에너지학회 논문집
• /
• 제30권3호
• /
• pp.33-38
• /
• 2010

The evaporative desalination system using solar thermal energy would be the efficient and attractive method to get fresh water from brine due to low carbon dioxide generation. In this research the solar desalination system as a heating source of refrigerant R123 in the evaporator was considered. The circulation of refrigerant in the evaporator can reduce the energy consumption of the system, because of using the latent heat of the refrigerant 123 instead of the sensible heat of present hot water. The system was comprised of the single-stage fresh water production unit on the capacity of 1ton/day with shell and tube type evaporator, heaters instead of solar collector to supply the proper heat to refrigerant, and refrigerant and brine circulation systems. Various operating flowrate and temperature ranges were varied in the experiments to get the optimum design data. The results showed that the optimum flow rate of brine feed rate to evaporator was 1.2Liter/min, and the yield of fresh water was increased as higher temperature of feed brine. It was confirmed that the circulation flowrate of heating source of refrigerant was decrease of one fifth of the present warm water system, and very efficient system for solar desalination.

• 한국철도학회:학술대회논문집
• /
• 한국철도학회 2009년도 춘계학술대회 논문집
• /
• pp.966-971
• /
• 2009

The recent environmental protection trend requires more strict energy saving, therefore every transportation system should reduce energy consumption to the minimum value. High-efficiency operation system, energy saving and CO2 emissions shall be addressed as important issue in railway system. These issues are the most essential factors of railway, compared to major public transportation system. Recently, saving energy in the electric railway system has been studied. For such new energy saving, the Energy storage system is considered for saving energy. Energy saving is possible by efficient use of regenerated energy. Regenerated energy is recycled amongst vehicles by mean of charge and discharge corresponding to powering and braking of electric vehicle operations. This energy saving contributes to cut CO2 to reduce greenhouse gas emissions. Recycling regenerated energy demonstrate significant effect on peak cut of consumption energy in railway substation. Absorption of excess energy avoids regeneration failure due to high traction voltage. This paper presents effects by applying the energy storage system to SeoulMetro Line 2.

• KIEAE Journal
• /
• 제13권5호
• /
• pp.97-102
• /
• 2013

Many countries over the world have acknowledged the global warming problem by greenhouse gas emission and tried to solve the problem. The Korean government has also taken many actions such as The Act on Low Carbon, Green Growth and on Promoting Green Building in that architectural building section takes 1/4 of national greenhouse gas emission. Under the situation that buildings constructed 15 years ago when insulation standards were reinforced take about 74%, The Plan on Vitalizing Green Remodeling, finally established on July 2013, will induce energy-efficient remodeling of deteriorated buildings. Using the energy simulation by the Visual DOE 4.0 program, this paper proposed the ways of energy-efficient remodeling of deteriorated high school buildings by measuring energy saving performance of factors that were drawn from the previous study. The factors considered are insulation, window's SHGC, south louver, system efficiency, and indoor setting temperature. Among them, all factors except SHGC proved contribution to reducing energy use at deteriorated high school buildings, compared with the baseline energy consumption.

• 신재생에너지
• /
• 제4권4호
• /
• pp.10-16
• /
• 2008

Nowaday, The Sustainable Development about global environment is the most important subject. In urban environment, a variety of the nature energy utilization such as the solar energy are the most efficient solution to solve this issue. One of these efficient solutions, a photovoltaic system using sunlight has been introduced to the building with an advantage such as cost-effective, safe for using and good for environment friendly in light with energy utilization. Recently, many of the apartment housings are built in domestic country. The apartment buildings have been constructed since early of 1970's. now apartment is taking over 50% out of entire housing in korea. The apartment housing applying to a photovoltaic system has been extensively studied in the foreign country but our county runs short. So, It was necessary to technical development of PV application which is suitable in Korean house culture. The objective of this study is to develop the building integrated PV application method for apartment building.

• 한국정보통신학회:학술대회논문집
• /
• 한국해양정보통신학회 2010년도 추계학술대회
• /
• pp.531-534
• /
• 2010

본 논문에서는 공유형 태양 에너지 기반 센서 시스템을 위한 가상 에너지 시스템의 개념을 이용한 효율적인 에너지 관리 기법을 소개한다. 가상 에너지 시스템은 한 센서 노드에서 동시에 수행되는 여러 응용들이 각각 자신이 사용할 에너지양을 예약하여 사용할 수 있게 하는 추상화 계층이다. 이렇게 함으로서 응용과 시스템의 수정 없이, 수집되는 태양 에너지를 각 응용에서 조화롭게 사용할 수 있고, 따라서 태양 에너지의 효율적 사용이 가능하게 된다. 실험 결과는 가상 에너지 시스템이 효율적이고 안정적으로 동작하여, 한 센서 노드에서 여러 응용이 조화롭게 실행됨을 보여주고 있다.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제7권12호
• /
• pp.3018-3036
• /
• 2013

In this paper, we investigate power allocation scheme and outage performance for a physical-layer network coding (PNC) relay based secondary user (SU) communication in cognitive multi-antenna relay networks (CMRNs), in which two secondary transceivers exchange their information via a multi-antenna relay using PNC protocol. We propose an optimal energy-efficient power allocation (OE-PA) scheme to minimize total energy consumption per bit under the sum rate constraint and interference power threshold (IPT) constraints. A closed-form solution for optimal allocation of transmit power among the SU nodes, as well as the outage probability of the cognitive relay system, are then derived analytically and confirmed by numerical results. Numerical simulations demonstrate the PNC protocol has superiority in energy efficiency performance over conventional direct transmission protocol and Four-Time-Slot (4TS) Decode-and-Forward (DF) relay protocol, and the proposed system has the optimal outage performance when the relay is located at the center of two secondary transceivers.

• 청정기술
• /
• 제16권1호
• /
• pp.59-63
• /
• 2010

가소제 등의 중간원료로 사용하는 2-에틸헥산올의 농축공정에 기존의 2 탑 증류 시스템 대신 에너지 절약형 증류탑인 열복합 증류탑을 사용할 때의 에너지 절감효과를 시뮬레이션을 통하여 계산하였다. 기존의 2탑 증류방식에 비해 약 41%의 에너지 절감효과가 있음을 계산의 결과로부터 알 수 있었으며, 에너지 절감의 원인을 증류곡선으로 설명하였다. 또, 기존 공정 대신 열복합 증류탑을 사용하면 증류탑의 운전비용뿐만 아니라 설비비의 절감도 가능한 추가적인 이득이 있다.