• KIPS Transactions on Software and Data Engineering
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• v.7 no.9
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• pp.335-344
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• 2018

The power model is needed to handle the power consumption of mobile AMOLED display at the software level. However, the existing studies to generate the power model have required the experimental environment and equipment for the power measurement activity. In addition, the combination of RGB values used for modeling was imprudent and small, so it was difficult to reflect the mutual influence between the RGB values into the model. To solve these problems, we propose an RGB color space partitioning method, which is used to prudently sample the combinations of the RGB values based on the color or the power. We also propose a process for generating a mapping table composed of . We analyzed the characteristics of the samples generated according to the proposed partitioning methods, taking into account the color and the power, and generated the mapping table for the AMOLED display. Furthermore, we confirmed the reusability of the mapping table by utilizing one mapping table multiple times in evaluating different power models. These mapping tables are provided to researchers and can be used to generate and evaluate power models without power measurement activities.

• Proceedings of the Korea Information Processing Society Conference
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• 2010.11a
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• pp.1662-1665
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• 2010

그린 컴퓨팅의 일환으로 데이터 센터(Data Center)의 전력 효율을 고려한 소프트웨어/하드웨어 기술연구가 활발하게 진행되고 있다. 데이터 센터에서는 부하 분산(Load Balancing) 서비스의 마이그레이션(Migration) 기법을 통해 서비스의 품질을 높이고 데이터 센터의 효율성을 극대화 시킨다. 본 논문에서는 데이터 센터에서 냉각으로 소모되는 전력 절감을 위해 데이터 센터의 환경과 시스템 부하(Work Load)량에 기반을 둔 프로세스 마이그레이션(Process Migration) 기법을 제안한다.

• Proceedings of the Korea Society for Simulation Conference
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• 2005.11a
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• pp.108-112
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• 2005

유비쿼터스 컴퓨팅의 기반 설비인 센서 네트워크는 많은 수의 센서 노드들로 구성되며, 각 센서 노드의 하드웨어는 매우 작은 규모이다. 또한 센서 네트워크는 구축 목적에 따라 네트워크 토폴로지 및 라우팅 방식이 결정되어야 하고, 이와 더불어 센서 노드의 하드웨어와 소프트웨어도 필요에 따라 다양하게 변경되어야 한다. 따라서 센서 네트워크가 구현되기 전에 시스템 동작과 성능을 예측할 수 있는 센서 네트워크 시뮬레이터가 필요하다. 기존의 센서 네트워크 시뮬레이터들은 특별한 응용을 위한 특정 기반의 하드웨어와 운영체제에 국한되어 개발되었기 때문에 다양한 센서 네트워크 환경을 지원하기에는 한계가 있으며, 센서 네트워크 설계상의 주요 요소인 전력소모량과 실행 시간에 대한 분석이 포함되지 않았다. 따라서 본 연구에서는 특정한 응용이나 운영체제에 제한을 받지 않으면서 다양하게 센서 네트워크 환경을 설계 및 검증할 수 있고, 더불어 전력소모량과 실행시간 추정도 가능한 시뮬레이터를 개발하는 것을 목표로 하였다. 이를 위해 본 연구에서 개발한 시뮬레이터는 기계명령어-레벨(machine instruction-level)의 이산-사건 시뮬레이션(discrete-event simulation) 기법을 이용함으로써 실제 센서 노드의 프로그램 실행 및 관련 동작들을 세부적으로 예측하는 데 사용될 수 있도록 하였다. 시뮬레이션의 작업부하(workload)인 명령어 트레이스(instruction trace)로는 ATmega128L 마이크로컨트롤러용으로 크로스 컴파일된 인텔 핵스-레코드(.hex) 형식을 사용한다.

• Journal of Korea Society of Industrial Information Systems
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• v.12 no.3
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• pp.95-103
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• 2007

Portable multimedia Player (PMP) devices have been gaining in its popularity with the emerging digital convergence of data, video, audio, etc. Since the PMP devices are typically equipped with DSP, a bigger LCD screen, and a hard disk, efficient power management has become more crucial than the other portable devices. This paper builds up a hardware/software-based power measurement system based on data acquisition devices. Subsequently, it measures and analyzes the power consumed in commercial PMP devices under different types of events: the system boot & shutdown, video playback, and the use of different video-coding types. Finally, our analysis of the measured power consumption patterns reveals useful information for the design of low-power PMP devices.

• Proceedings of the Korean Information Science Society Conference
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• 2004.10c
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• pp.37-39
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• 2004

Mobile IPv6 기술은 단말의 이동성을 제공하는 기술로서 AII-IP기반의 차세대 유무선 통합 망 구축을 위한 핵심 기술이다. 기존의 소프트웨어 Mobile IPv6는 특정 OS에 의존적일 뿐 아니라, OS 구동 시 발생하는 오버 헤드로 인한 높은 전력 소모로 인해 시스템의 성능이 저하되는 문제점이 있다. 이에 본 논문에서는 기존 소프트웨어 기반 Mobile IPv6의 문제점을 해결하고 최신 표준에 따르는 이동성과 고속 통신을 제공하기 위한 하드웨어 Mobile IPv6를 설계 및 구현하였다. 그리고 구현된 모듈은 시험 망 패킷 데이터와 시뮬레이션을 통해 동작을 검증하였다.

• Proceedings of the Korea Information Processing Society Conference
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• 2014.04a
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• pp.836-839
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• 2014

전력 소모가 심한 전광판을 소프트웨어를 통해서 전력 소비를 줄이고 전광판 관리자가 인터넷이 가능한 환경이라면 App 으로 언제 어디서나 광고 및 정보를 관리할 수 있다. 또한 사용자들은 전광판 앞에서 간단한 손동작으로 다양한 광고 넘겨가며 볼 수 있도록 구현했다.

• Journal of KIISE:Computing Practices and Letters
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• v.15 no.11
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• pp.801-805
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• 2009

Hardware based dynamic voltage and frequency scaling is a promising technique to reduce power consumption in a globally asynchronous locally synchronous system such as a homogeneous or heterogeneous multi-core system. In this paper, FPGA prototype design of hardware based dynamic frequency scaling is proposed. The proposed techniques are applied to a FIFO based multi-core system for a software defined radio and Network-on-Chip based hardware MPEG2 encoder. Compared with a references system using a single global clock, the first prototype design reduces the power consumption by 78%, but decreases the performance by 5.9%. The second prototype design shows that power consumption decreases by 29.1% while performance decreases by 0.36%.

• The KIPS Transactions:PartA
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• v.18A no.3
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• pp.93-98
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• 2011

While the use of battery-powered embedded systems has been rapidly increasing, the current level of battery technology has not kept up with the drastic increase in power consumption by the system. In order to prolong system usage time, the battery size needs to be increased. The amounts of power consumption by embedded systems are determined by their hardware configuration and software for manipulating hardware resources. In spite of that, the hardware provides features for lowering power consumption, if those cannot be utilized efficiently by software including operating system, reduction in power consumption is not optimized. In this paper, we propose a BET(Break Even Time)-based scheduling method using task partition to reduce power consumption of multimedia applications in a mobile embedded system environment.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.46 no.9
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• pp.39-48
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• 2009

Human face tracking has gradually become an important issue in applications for portable multimedia devices such as digital camcorder, digital still camera and cell phone. Current embedded face tracking software implementations lack the processing abilities to track faces in real time mobile video processing. In this paper, we propose a power efficient hardware-based face tracking architecture operating in real time. The proposed system was verified by FPGA prototyping and ASIC implementation using Samsung 65nm CMOS process. The implementation result shows that tracking speed is less than 8.4 msec with 150K gates and 20 mW average power consumption. Consequently it is validated that the proposed system is adequate for portable multimedia device.

• KIPS Transactions on Software and Data Engineering
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• v.9 no.12
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• pp.419-430
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• 2020

This paper investigated methods to improve the forecasting accuracy of the electricity consumption prediction model. Currently, the demand for electricity has continuously been rising more than ever. Since the industrial sector uses more electricity than any other sectors, the importance of a more precise forecasting model for manufacturing sites has been highlighted to lower the excess energy production. We propose a double encoder-decoder model, which uses two separate encoders and one decoder, in order to adapt both long-term and short-term data for better forecasts. We evaluated our proposed model on our electricity power consumption dataset, which was collected in a manufacturing site of Sehong from January 1st, 2019 to June 30th, 2019 with 1 minute time interval. From the experiment, the double encoder-decoder model marked about 10% reduction in mean absolute error percentage compared to a conventional encoder-decoder model. This result indicates that the proposed model forecasts electricity consumption more accurately on manufacturing sites compared to an encoder-decoder model.