• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.18 no.6
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• pp.169-180
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• 2018

White light-emitting diodes (LEDs) are more economical than fluorescent lights, and provide high brightness, a high lifetime expectancy, and greater durability. As LEDs are closely connected with people's daily lives, dimming control of LED is an important component in providing energy savings and improving quality of life. In visible light communications systems using these LEDs, multiple input multiple output (MIMO) technology has attracted a lot of attention, in that it can attain the channel capacity in proportion to the number of antennas. This paper analyzes the power performance of three kinds of modulation in visible light communications (VLC) systems applied space-time block code (STBC) techniques. The modulation schemes are return-to-zero on-off keying (RZ-OOK), variable pulse position modulation (VPPM), and overlapping pulse position modulation (OPPM), and dimming control was applied. The power requirements and power consumption were used as metrics to compare the power efficiency in $2{\times}2$ STBC-VLC environments under the three kinds of modulation. We confirm that dimming control affects the communications performance of each modulation scheme. VPPM showed greater consumption among the three modulations, and OPPM showed energy savings comparable to VPPM.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.316-317
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• 2011

본 연구에서는 일반 사무 건물을 대상으로 주광을 이용 하여 작업 시 조도에 따른 사용자의 만족도를 높이고 가변 전기요금에 따른 요금을 절감 하는 최적의 조도를 설정하여 조광을 제어하는 방식으로 조명 에너지를 절감하는 기법을 제안한다.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2001.02a
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• pp.251-256
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• 2001

• The Magazine for Energy Service Companies
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• s.83
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• pp.60-67
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• 2013

본 문서는 정보통신산업진흥원에서 실시한 2012년 IT기반 ESCO시범사업의 수행결과를 활용한 것이다. 향후 IT 기술을 활용한 에너지 절감 사업을 수행하게 될 에너지 사용자 및 사업자에게 IT 기술을 활용한 에너지 절감 방법과 시스템 구축 및 운영 노하우를 공유하도록 제작되었다.

• The Korean Publising Journal, Monthly
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• s.152
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• pp.12-12
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• 1994

사학사는 역사서술의 역사이자 역사적 사유의 역사이기도 하다. 그런 점에서 사학사에 대한 연구는 인간지성의 전개과정에 대한 고찰이다. "한국의 역사가와 역사학"은 한국지성사 이해의 길라잡이다. 그러나 세계정신사적 스펙트럼에서 우리 역사인식의 고유한 특성.수준을 규명하는 데 미흡하다. 이 책은 그것을 뒷날의 연구자들에게 위임한다.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.17 no.5
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• pp.8-14
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• 2003

The daylight responsive dimming system, which uses daylight and automatically controls the light output of electric lighting according to the amount of 3.vailable daylight, is an energy saving system Successful performance relies on how photosensor signal can precisely represent workplace illuminance. However, it is not accurately identified due to the dynamic nature of the sun and the sky changed with respect to different seasons or time. The purpose of this research is to identify the correlation between workplace illuminance and photosensor signals, and propose an optimal location and spatial characteristics of the photosensor through experiments, which minimizes the above impacts and improve system performance.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.9 no.4
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• pp.792-797
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• 2005

Lighting control switches based on the power line communication technology are developed and extended to incorporate dimming control to provide energy saving and appropriate illumination. The developed switch uses a general purpose microprocessor and associated electronics. Both the power line communication and the dimming function are implemented in one microprocessor, and it enables the low price commercialization. The frequency of the carrier was set at 250kHz considering the transmission data length and signal attenuation in power lines. Tests on prototypes in an low-voltage power lines have shown that the switches have a robust operation characteristics with the length of power lines and the variation of load capacities.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.22 no.11
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• pp.788-797
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• 2010

This study examines the influence of fluctuating daylight illuminance on daylight dimming control systems. Field measurements were performed for a full-scale mocked-up model under various daylight conditions in winter. Fluctuating ranges for a partially-shielded photosensor were great when the variation of sky ratio was great. When solar altitude was lower the illuminance and fluctuating range of illuminance were great due to the influence of direct components of daylight and the interrefelction between surfaces in rear area of space. It implies that daylight dimming system would not function effectively, unless the desktop illuminance by daylight is enough. Fluctuation ranges of photosensor illuminance were lower than 50 lx under clear sky conditions, but they were greater than 100 lx under partly-cloudy sky conditions. It means that the fluctuation range of electric light output of lighting fixture would greater under the partly-cloudy conditions and cause potential visual annoyance to occupants. Outdoor vertical illuminance reaching the windows would be an effective factor that can be used to predict the fluctuation of photosensor signals for effective controls of daylight dimming system.

• JOURNAL OF ELECTRICAL WORLD
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• s.264
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• pp.70-78
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• 1998

석유 등의 화석연료가 연소되면서 발생하는 이산화탄소를 주체로 하는 ''온실효과가스''의 배출량이 점점 더 증가해 감에 따라 지구온난화가 국제적으로도 커다란 환경문제가 되고 있다. 이산화탄소의 배출을 억제하기 위한 구체적인 시책은 바로 자에너지(에너지 절약/ 이용합리화)의 수행이다. 이번에 자에너지를 주목적으로, ISO14001의 환경매니지먼트 모델을 전체적으로 지원하는 공장에너지관리시스템과 조명$\cdot$빌딩분야에서 환경매니지먼트 모델을 지원하는 조명제어시스템 및 빌딩 설비 감시시스템을 구축하였다. 신규개발한 Controller의 소프트웨어는 24시간 가동가능한 OS(Operating System)에 제어미들웨어를 탑재하여 Object설계방법으로 제작된 기능별 어플리케이션 소프트웨어를 각 시스템별로 조합한다. 하드웨어는 퍼스컴과 동일한 DOS/V머신 구성으로 하여 시스템의 주체가 되는 부송부의 하드웨어를 개발하였다. 구축한 각 시스템의 내용은 다음과 같다. (1)공장에너지관리시스템 수집한 에너지사용량 데이터를 관리$\cdot$분석용으로 가공하는 생에너지 지원용 어플리케이션 소프트웨어를 탑재하고있어 환경매니지먼트 시스템(ISO14001)을 실행하는 데에도 유용하다. (2)조명제어시스템 지금까지 단독기기였던 조도일정제어의 조광컨트롤러에 B/NET 전송기능을 탑재하여 스케줄 및 디맨드 감시에 의한 조광제어를 시행하여 한층 더 생에너지를 실현한다. (3)빌딩설비 감시시스템 빌딩의 에너지관리, 조명$\cdot$공조제어에 의한 생에너지화, 보전업무의 효율화$\cdot$생력화를 실현한다.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.45 no.2
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• pp.83-91
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• 2008

To design the light control system using the PLC(Power Line Communication) with the ballasts of MH(Metal Halide) lamps, we analyzed the noise effect on the power line by the electronic ballast. For the power line characteristics are changed by the loads, the ballast have to be designed to be suitable to the PLC. Therefore, this paper proposed the optimal ballast and designed two kinds of PLM(Power Line Modem) which one is ASK type and the other is FSK type. Two type of PLM have used the manchester codes or DS/SS code. Experimental results have shown that the FSK type modem by the DS/SS coding technique have the best characteristics.