• 한국정보통신설비학회:학술대회논문집
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• 2005.08a
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• pp.358-363
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• 2005

본 논문에서는 전력 제어를 통해 에너지 소비를 최소화하여 네트워크 수명을 극대화 시킬 수 있는 효율적인 라우팅 방안을 제안하였다. 제안한 프로토콜에서 센서 노드들은 여러 개의 단위 전력을 가지고 있어 독립적인 라우팅 테이블을 형성하게 된다. 이를 토대로 가장 에너지 소비가 적은 경로를 설정하여 데이터를 전송하게 된다. 또한 특정 노드가 더 이상 기능을 하지 못하는 경우에도 적응적으로 경로를 재설정하여 데이터를 전송할 수 있도록 설계하였다. 이렇게 제안한 프로토콜과 기존의 방식과의 비교 실험을 통해 제안한 라우팅 방식의 성능을 효율적 에너지 소비 측면에서 분석하였다. 그 결과 논문에서 제안한 프로토콜의 성능이 기존의 방식과 비교하여 향상되었음을 확인하였다.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.44 no.11
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• pp.51-55
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• 2007

Generally, PLC (Power Line Communication) based home automation devices such as wall switch, walt socket, gas controller, etc, must maintain wake-up status at all time to control other electronic devices and monitor their on/off status whether they are in service or not. In order to reduce the unnecessary energy consumption during the standby mode, the new power-saving PLC 2 ports wall switch has been developed, separating PLC communication part and controller part and introducing sleep mode. In addition, to expand life cycle of PLC product and to reduce the rate of product failure in active mode, the instant controlling method in controlling process is adopted instead of the maintenance controlling method. In comparison to the earlier model, the new 2 ports PLC wall switch has reduced power by 0.95[W] less in standby mode and 3.2[W] less in active mode than the previous one.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.9 no.1
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• pp.39-45
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• 2009

OFDM is used for achieving a high-speed data transmission in mobile wireless communication systems. Conventionally, fast Fourier transform that is the main signal processing of OFDM is implemented using digital signal processing. The DSP FFT LSI requires large power consumption. Current-mode FFT LSI with analog signal processing is one of the best solutions for high speed and low power consumption. However, for the operation of current-mode FFT LSI that has the structure of parallel-input and parallel-output, current-mode serial-to-parallel and parallel-to-serial converter are indispensable. We propose a novel current-mode SPC and PSC and full chip simulation results agree with experimental data. The proposed current-mode SPC and PSC promise the wide application of the current-mode analog signal processing in the field of low power wireless communication LSI.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.45 no.8
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• pp.37-43
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• 2008

This paper introduces a high-speed low-power self-timed current-mode logic (STCML) that reduces both dynamic and leakage power dissipation. STCML significantly reduces the leakage portion of the power consumption using a pulse-mode control for shorting the virtual ground node. The proposed logic style also minimizes the dynamic portion of the power consumption due to short-circuit current by employing an enhanced self-timing buffer. Comparison results using a 80-nm CMOS technology show that STCML achieves 26 times reduction on leakage power consumption and 27% reduction on dynamic power consumption as compared to the conventional current-mode logic. They also indicate that up to 59% reduction on leakage power consumption compared to differential cascode voltage switch logic (DCVS).

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2008.10a
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• pp.600-603
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• 2008

In this paper, a new circuit design named memory-in-pixel for low power consumption of the liquid crystal display (LCD) is presented. Since each pixel has a memory, it is able to express 8 color grades using the data saved in the memory without the operation of the gate and source driver ICs so that it can reduce the power consumption of the LCD panel. A memory circuit consists of modified S-R flip-flop (NAND-type) implemented in the pixel, which can supply AC bias for operating the liquid crystal (LC) with the interlocking clocks (CLK_A and CLK_B). This circuit is more complex than the inverter-type memory circuit, but it has lower power consumption of approximately 50% than the circuit. We have investigated the power consumption both NAND and inverter-type memory circuit using a Smart SPICE for the resolution of $96{\times}128$. The estimated power consumption of the inverter-type memory was about 0.037mW. On the other hand, the NAND-type memory showed power consumption of about 0.007mW.

• The KIPS Transactions:PartA
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• v.19A no.3
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• pp.139-146
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• 2012

In the server cluster environment, one of the ways saving energy is to control server's power according to traffic conditions. This is to determine the ON/OFF state of servers according to energy usage of data center and each server. To do this, we need a way to estimate each server's energy. In this paper, we use a software-based power consumption estimation model because it is more efficient than the hardware model using power meter in terms of energy and cost. The traditional software-based power consumption estimation model has a drawback in that it doesn't know well the computing status of servers because it uses only the idle status field of CPU. Therefore it doesn't estimate consumption power effectively. In this paper, we present a CPU field based power consumption estimation model to estimate more accurate than the two traditional models (CPU/Disk/Memory utilization based power consumption estimation model and CPU idle utilization based power consumption estimation model) by using the various status fields of CPU to get the CPU status of servers and the overall status of system. We performed experiments using 2 PCs and compared the power consumption estimated by the power consumption model (software) with that measured by the power meter (hardware). The experimental results show that the traditional model has about 8-15% average error rate but our proposed model has about 2% average error rate.

• Environmental and Resource Economics Review
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• v.22 no.3
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• pp.547-580
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• 2013

As energy conservation can be realized through changes in the composition of goods and services consumed, there is a need to assess indirect and total household energy consumption. The Korean household sector was responsible for more than 55% of Korea's total energy consumption in the 1995 to 2010 period. More than 69% of household energy consumption was indirect. Thus, not only direct but also indirect household energy consumption should be the target of energy conservation. Electricity consumption became in 2009 the main source of household energy consumption in Korea. Households consume more and more electricity intensive goods and services, a sign of increasing living standards. Decrease in energy intensities of products consumed by Korean households contributed greatly to reduce the increase in the total household energy consumption. However, switching took place towards more energy intensive products, thus the structure effect was negative. It is necessary to direct consumption and production towards much less energy intensive goods and services as to reduce energy consumption or its growth rate. The Korean government should readjust low energy and electricity prices to cost-reflective prices levels as these low prices are one of the main reasons for the consumption of more energy intensive products. This study differentiates prices of oil products and electricity between households and industries, as to allow more accurate estimation.

• Proceedings of the Korea Institutes of Information Security and Cryptology Conference
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• 2006.06a
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• pp.141-147
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• 2006

부채널 정보를 이용한 공격이 제안된 이후, 스마트카드와 RFID와 같은 저 전력 정보보호 장치 내부의 암호 프로세서에서 소비되는 전력을 분석하여 암호 연산에 사용된 비밀 정보를 알아내는 공격 방법은 가장 위협적인 물리적 공격 방법으로 알려져 있다. 하지만 측정된 소비 전력 신호를 시간 영역에서 분석하는 기존의 분석 기법들은 암호 연산 시점이 시간 축 상에서 동일하여야 된다는 단점을 가지고 있다. 제안하는 주파수 분석 공격 방법은 공격이 적용되는 장치에서 측정된 시간 영역에서 정렬되지 않는 신호를 Fourier 변환을 하여 주파수 영역에서 분석함으로써 기존 전력 분석 공격이 시간 영역에서 정렬된 소비 전력 신호를 필요로 하는 문제점을 해결하였다. UC Berkeley에서 제작된 능동형 RFID 모듈에 국내 표준인 ARIA 알고리즘을 응용프로그램으로 탑재하여 기존 전력 분석 공격과 제안하는 주파수 분석 공격을 적용하여 결과를 분석 하였다.

• Proceedings of the Korean Information Science Society Conference
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• 2012.06d
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• pp.4-6
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• 2012

모바일 환경에서는 배터리 용량의 한계로 에너지 효율성이 매우 중요하나, CPU의 이용률에 기반한 DVFS로는 소비 전력 감소에 한계가 존재한다. 모바일 어플리케이션은 사용자와의 상호 동작에 따라 다른 성향을 보여주기 때문에, 이 특성을 이용하여 사용자가 체감하는 성능저하 없이 소비 전력을 줄일 수 있다. 본 논문에서는 사용자 입력과 어플리케이션 간의 상관 관계를 바탕으로 수행 단계를 분석하였으며, 이에 맞추어 CPU 동작 주파수 범위를 조절함으로써 사용자 반응성을 유지하면서 소비 전력을 줄이는 방법을 제안한다. 이를 안드로이드 플랫폼에 적용하여 실험한 결과, 기존 대비 휴대폰의 이용 시간을 최대 2시간 증가시켰다.

• 한국정보통신설비학회:학술대회논문집
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• 2004.08a
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• pp.105-108
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• 2004

유비쿼터스 컴퓨팅에서 센서 네트워크는 상황인지를 위한 가장 기본적인 인프라 기술이다. 또한 기존의 네트워크를 이용하지 않고 독립적인 네트워크를 구성한다. 그러므로 센서 네트워크는 각자 독립적인 전력을 사용한다. 이러한 특성상 전력 소비의 문제가 가장 중요한 기술적 난제로 존재한다. 전력소비의 문제를 개선하기 위해서는 다양한 방법이 존재 한다. 네트워크를 형성하기위한 센싱정보의 효율적인 전송 방법이 필요하다. 본 논문에서는 상황정보를 표현하기 위한 방법을 제안하고 표현된 정보를 사용하여 RF 데이터 전송의 여부를 결정함으로써 전송에 따른 전력 소비를 효율적으로 추구한다.