• Applied Chemistry for Engineering
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• v.26 no.3
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• pp.247-250
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• 2015

Organic light-emitting diode (OLED) research field has received great attention from academic and industrial circles. Recently, The technical feature of OLEDs is more and more attractive in the lighting market, including area emission characteristics different from other existing light sources. Features are environmentally friendly and efficient use of energy, large area, ultra-light weight, and ultrathin shape, etc. Furthermore, OLED light became the mainstream of next-generation lighting to replace the light emitting diode (LED) fluorescent light. This article summarizes phosphorescent emitting materials that have been applied to white OLEDs. In particular, the chemical structures and device performances of the important yellow, orange, and red phosphorescent emitting materials is discussed. Systematic classification and understanding of the phosphorescent materials can aid the development of new light-emitting materials.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.10 no.1
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• pp.23-30
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• 2017

Currently, road lightings are installed with less than 400W of existing metal halide lamps. These road lightings are being replaced by energy-saving lightings. Induction lamps are expected to be more actively replaced with targets for tunnel lighting and high ceiling lighting. Therefore, it is necessary to develop high efficiency, high power induction lamps system. In this study, the gas type & pressure, amalgam type were designed for the high power of the induction lamps. And induction lamp system was optimized through electrical, optical characteristics analysis. It is optimized to the gas pressure 300~350 [mmHg] for the discharge tube of high power induction lamp and ferrite core. The driving circuit matching was completed with a induction lamp using indium amalgam. The rated power consumption of the induction lamp was optimized with 250 W (rated ${\pm}10%$)

• Journal of Satellite, Information and Communications
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• v.6 no.1
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• pp.57-62
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• 2011

The VLC (visible light communication) system is communication technology using visible rays (RGB) that come out in LED device. It is energy curtailment effect and possible in ubiquitous network service applications. Also, VLC system has the above advantage about that the communication throughout the whole room is enabled by high power lighting and lighting equipment with white colored LED which are easy to install and have good outward appearance. However, the signal detection performance for the receiver near the network of transmitter boundary is severely degraded and the transmission efficiency decreased due to the influence of the interference signal from the adjacent networks. In this paper, we propose an interference mitigation method with optical beamforming in VLC systems, and evaluate the reception performance. For the system BER, the proposed optical beamforming transmission demonstrates the performance enhancement compared to the not using the optical beamforming scheme, and up to about 5~6dB SNR performance gain is achieved.

• Journal of Satellite, Information and Communications
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• v.7 no.3
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• pp.63-68
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• 2012

The VLC (visible light communication) system is communication technology using visible rays (RGB) that come out in LED device. It is energy curtailment effect and possible in ubiquitous network service applications. Also, VLC system has the above advantage about that the communication throughout the whole room is enabled by high power lighting and lighting equipment with white colored LED which are easy to install and have good outward appearance. However, the signal detection performance for the receiver near the network of transmitter boundary is severely degraded and the transmission efficiency decreased due to the influence of the interference signal from the adjacent networks. In this paper, we propose an interference mitigation method with optical relay and optical beamforming scheme in VLC systems, and evaluate the reception performance. For the system BER, the proposed system demonstrates the performance enhancement compared to the not using the optical relay and optical beamforming scheme, and SNR performance gain and higher channel capacity is achieved.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.9 no.4
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• pp.43-51
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• 2010

In this paper, we studied line coding technology tendency for high speed data communication at LED-ID (Identification) communication system in indoor environment. A LED-ID technology is a communication using visible ray (RGB) that come out in LED device. It is energy curtailment effect and possible in ubiquitous network service applications. The LED-ID system has the above advantages about that the communication throughout the whole room is enabled by high power lighting and lighting equipment with white colored LED which are easy to install and have good outward appearance. Therefore, the transmission by light waves is more suitable for wireless networks than by radio waves. We compared with the NRZ, AMI, 4B5B, HDB3, 8B10B line coding for efficient in error detection and serves data transmission of high speed.

• International Journal of Internet, Broadcasting and Communication
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• v.12 no.2
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• pp.1-7
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• 2020

The secure access the lighting, Heating, ventilation, and air conditioning (HVAC), fire safety, and security control boxes of building facilities is the primary objective of future smart buildings. This paper proposes an authorized user access to the electrical, lighting, fire safety, and security control boxes in the smart building, by using color grid coded optical camera communication (OCC) with face recognition Technologies. The existing CCTV subsystem can be used as the face recognition security subsystem for the proposed approach. At the same time a smart device attached camera can used as an OCC receiver of color grid code for user access authentication data sent by the control boxes to proceed authorization. This proposed approach allows increasing an authorization control reliability and highly secured authentication on accessing building facility infrastructure. The result of color grid code sequence received by the unauthorized person and his face identification allows getting good results in security and gaining effectiveness of accessing building facility infrastructure. The proposed concept uses the encoded user access authentication information through control box monitor and the smart device application which detect and decode the color grid coded informations combinations and then send user through the smart building network to building management system for authentication verification in combination with the facial features that gives a high protection level. The proposed concept is implemented on testbed model and experiment results verified for the secured user authentication in real-time.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.14 no.5
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• pp.95-102
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• 2014

In this paper, we propose the high speed PLC-based automatic control system for a smart LED streetlight. The proposed the automatic control system were constructed of a power line modem part and monitoring part, streetlight controller part for the high speed communication frequency band and streetlight ballasts characterization and real-time remote control using a high-speed PLC network, and it was designed to meet to lighting grades conditions of KS road lighting standards. The proposed automatic control system were easy monitoring of the power consumption using PC through to the comparison result of the existing streetlight system. As a result, it was confirmed to the possibility of efficient operation for the real-time monitoring and maintenance by induction of reasonable power consumption through to the LED streetlight state checking and remote-control. In addition, we proved to improvement of expected effects for the power cost savings, the energy efficiency, and streetlight differentiation and advanced.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.3
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• pp.730-739
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• 2013

More than 30% of energy in Korea was spent in lighting part and then the consumption level and $CO_2$ emission will be increase from now. In this like situation, control-system construction for street-lamp of a smart grid-based that it has important meaning. Nowadays as a result, as an trying to utilize using Power-line-network communication modem and application a terminal in industrial fields, in this paper, we are want to implement the Power-line-network communication control system of PC-based. Therefore it will be use varied communication test-equipment and tools through the system. For experimentation, using the MODEM was able to use Planet production of based on the ZIC protocol and then the application program use the LabView. The result is primarily focused on equipments control by the PLC, and that we are able to perform each test with PLC equipment for experiment it.

• Journal of the Speleological Society of Korea
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• no.95
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• pp.15-21
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• 2009

Global village warming and carbon dioxide CO2 gas, and the human efforts for their healing and necessary alternative technology would be much more difficult things than that of making necessary funds and efforts to lay to sleep angry nature on the earth. The limited natural resources of fossil fuel would be dried up in several decades, and the intensity of diplomatic negotiations for natural resource guarantee among countries may be showed looking alike an war. The drain of fossil fuel called a new word of alternative policy like an environment-friendly green-growth, and the solar-cell and lighting technology for the solar energy applications were developed still more repeatedly day by day from oil lantern to LED high-tech illumination in great economy. Therefore, it was studied that the low-carbon green-growth illumination technology in cave applications with SOLAR-LED system which was produced and unified in connection with solar-cell and LED from the semiconductor production technology, and it was also clarified in necessary with useful cave lighting in heatless and with no photosynthesis of plant production in underground space.

• Korean Chemical Engineering Research
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• v.53 no.4
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• pp.468-471
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• 2015

Microalgae have the advantages of being able to utilize the solar energy and culturing at a low cost. In particular, microalgae have a great potential in the production of biodiesel due to the high lipid content. Lipids produced from microalgae are converted to fatty acid methyl ester (FAME) by trans-esterification reaction and FAME is called a biodiesel in general. In addition, microalgae can also be utilized as a substrate for ethanol fermentation after saccharification reaction. In this study, three types of microalgae (Nanochloris, Dunaliella tertiolecta, Tetraselmis) were cultured and their lipid contents were compared. In addition, the effects of lighting period on the growth rate and lipid content were studied. Finally, the amounts of glucose produced from each saccharified microalgae were investigated. As a result, we demonstrated that D. tertiolecta has 43.6% higher lipid content and 22% higher glucose conversion than two others.