• 설비공학논문집
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• 제20권2호
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• pp.97-105
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• 2008

This paper presents simulated and experimental test results of optimal control algorithm for an encapsulated ice thermal storage system with full capacity chiller operation. The algorithm finds an optimal combination of a chiller and/or a storage tank operation for the minimum total operation cost through a cycle of charging and discharging. Dynamic programming is used to find the optimal control schedule. The conventional control strategy of chiller-priority is the baseline case for comparing with the optimal control strategy through simulation and experimental test. Simulation shows that operating cost for the optimal control with chiller on-off operation is not so different from that with chiller part load capacity control. As a result from the experimental test, the optimal control operation according to the simulated operation schedule showed about 14 % of cost saving compared with the chiller-priority control.

• Journal of Advanced Marine Engineering and Technology
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• 제31권5호
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• pp.592-598
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• 2007

The fuel charge is getting higher in navigation cost. Therefore, shipowners try to find the method for reducing oil consumption. ESS(Energy Saving System) is one of he method. ESS is the system consisted with two inverters, ESS control unit and monitoring system. Two inverters control two main sea water cooling pumps. In the ESS control Unit, the control algorithm finds optimized point to decrease a power consumption of main sea water cooling pumps. Monitoring system observes ESS not to work improperly. ESS is experimented in the laboratory with real condition and analyzed in every view. After experiment, the result of the experiment shows that the control algorithm works correctly and safely. ESS has a plan to be operated in the ship soon. In that case, additional devices are needed to connect ESS with cooling system of the vessel. So the development of addition device is needed and being studied.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.344-346
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• 2006

In this paper, a novel algorithm for increasing the steady state efficiency during light load operation of the induction generator that integrated with a wind power generation system is presented. The proposed algorithm based on the flux level reduction, where the flux level is estimated using Support-Vector -Machines for regression (SVR) for the optimum d-axis current of the generator. SVR is trained off-line to estimate the unknown mapping between the system's inputs and outputs, and then is used online to calculate the optimum d-axis current for minimizing generator loss. The experimental results show that SVR can define the flux-power loss accurately and determine the optimum d-axis current value precisely. The loss minimization process is more effective at low wind speed and the percent of power saving can approach to 40%.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년 학술대회 논문집 정보 및 제어부문
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• pp.428-430
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• 2006

This paper proposes a new means of performance optimization for multimedia algorithm utilizing the Microscopic DVS (Dynamic Voltage Scaling). The Microscopic DVS technique controls the operating frequency and the supply voltage levels dynamically according to the processing requirement for each frame of multimedia data. The huffman decoding algorithm of MPEG-2 AAC audio decoder is optimized to maximize the power saving efficiency of Microscopic DVS technique. The experimental results show the reduction of computational complexity by more than 30% and the reduction of power consumption by more than 17% compared with those of the conventionally fast method.

• 대한전기학회논문지:시스템및제어부문D
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• 제55권12호
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• pp.544-546
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• 2006

This paper proposes a new means of performance optimization for multimedia algorithm utilizing the Microscopic DVS (Dynamic Voltage Scaling). The Microscopic DVS technique controls the operating frequency and the supply voltage levels dynamically according to the processing requirement for each frame of multimedia data. The huffman decoding algorithm of MPEG-2 AAC audio decoder is optimized to maximize the power saving efficiency of Microscopic DVS technique. The experimental results show the reduction of computational complexity by more than 30% and the reduction of power consumption by more than 17% compared with those of the conventionally fast method.

• 한국컴퓨터정보학회논문지
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• 제21권3호
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• pp.91-96
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• 2016

We have surrounded undesired living noises in our life. One of biggest noises coming out of range hood during cooking in the kitchen. A range hood is one of the most important appliances in the kitchen because it ventilates polluted air out during cooking, and maintains air quality in the kitchen. But current kitchen range hoods bring up some issues; First, the range hoods consume massive amount of standby power not in use condition. Second, current models have designed manual fan operating system with sudden onset of noise with starting. In this paper, we propose an auto control system entire processes from air ventilation to noise reduction. Our system is consist of three parts (Eco-sensors pack, Main Controller and Active Noise Controller); Eco-sensors pack detects air pollution of kitchen areas and sends the detection values to Main Controller. Main Controller determines operation of range hood by detected values. Active Noise Controller is located inside of the range hood. It received starting signals from Main Controller which elicits degrees of polluted air condition and fan operating speed from 1 to 3. Once Active Noise Controller detected the signals, it runs a ventilating fan until new value from Main Controller becomes 0. while the range hood works, A noise cancellation algorithm inside of Active Noise Controller become activated to reduce levels of noise. As a result, the proposed system clearly shows reduction in power consumption include standby power and decreases in levels of noise.

• 정보과학회 논문지
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• 제43권11호
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• pp.1298-1306
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• 2016

휴대용 기기에서 사용 비중이 높은 디스플레이인 TFT-LCD에서는 백라이트가 소모 전력의 대부분을 차지하므로 백라이트의 세기를 줄이는 디밍 기법을 통한 전력 절감이 많이 시도되고 있으며, 이 때 일어나는 디스플레이 상 이미지의 밝기 저하로 인한 시각적 왜곡을 개선하는 이미지 보상 기법 연구가 동시에 진행되고 있다. 하지만 히스토그램 평활화와 같은 기존 이미지 보상 기법들은 인간 시각 만족도를 잘 충족하는 것에 한계점을 가진다. 본 논문에서는 히스토그램 명세화와 픽셀 보정의 결합을 통해 전력 절감과 함께 시각 만족도 개선 효과가 향상된 디밍 기법을 제안한다. 이 기법은 인간 시각을 만족하기 위해 탐색 알고리즘을 수행하므로, 빠른 이미지 처리를 위해 단순화한 계산을 통해 인간 시각 만족의 이미지를 얻어낼 수 있는 자동화 알고리즘을 포함한다. 실험 결과, 기존 백라이트 디밍에 비해 전력 절감 대비 높은 시각 만족도 개선을 보였다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1991년도 한국자동제어학술회의논문집(국내학술편); KOEX, Seoul; 22-24 Oct. 1991
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• pp.1057-1062
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• 1991

Recently, due to the development of new technology and products, FA has been accelerating for obtaining high-quality and saving of resources and power. Introduction of automation to the field which has bad working condition is needed and welding is one of these field. In this study, solving algorithm for down hand control which requires in the automatic are welding system is proposed. For the verification of the algorithm, numerical examples are shown and visualization is carried out using developed graphic tools.

• 한국정밀공학회지
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• 제23권7호
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• pp.84-92
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• 2006

This paper deals with determination of motions of a humanoid robot using genetic algorithm. A humanoid robot has some problems of the structural instability basically. So, we have to consider the stable walking gait in gait planning. Besides, it is important to make the smoothly optimal gait for saving the electric power. A mobile robot has battery to move autonomously. But a humanoid robot needs more electric power in order to drive many joints. So, if movements of walking joint don't maintain optimally, it is hard to sustain the battery power during the working period. Also, if a gait trajectory doesn't have optimal state, the expected lift span of joints tends to be decreased. Also, if a gait trajectory doesn't have optimal state, the expected lift span of joints tends to be decreased. To solve these problems, the genetic algorithm is employed to guarantee the optimal gait trajectory. The fitness functions in a genetic algorithm are introduced to find out optimal trajectory, which enables the robot to have the less reduced jerk of joints and get smooth movement. With these all process accomplished by PC-based program, the optimal solution could be obtained from the simulation. In addition, we discuss the design consideration fur the joint motion and distributed computation of tile humanoid, ISHURO, and suggest its result such as structure of the network and a disturbance observer.

• 한국인터넷방송통신학회논문지
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• 제15권4호
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• pp.71-78
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• 2015

대학 등의 교육 기관은 대량의 PC들을 갖추고 있으므로, 이들의 전원 상태를 관리하지 않으면 많은 전력을 낭비할 수 있다. 본 논문은 대학 내 PC들에 대해, 원격으로 PC 들의 상태를 모니터링하여 PC의 전원 상태를 확인하거나, PC 전원을 끌 수 있는 전원 관리 시스템(Remote Power Manager, RPM)을 개발한 사례를 소개한다. RPM은 PC에서 독립적으로 전원을 관리하는 Power Controller 소프트웨어 모듈과, 전체 PC의 전원 상태를 관리하는 Power Server, 그리고 관리자가 각 PC의 전원 상태를 보거나 끌 수 있는 Power Viewer 소프트웨어 모듈로 구성된다. RPM 시스템을 설치하여 대학 내에서 실험한 결과 40% 정도 에너지를 절약하는 결과를 얻었다.