• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.26 no.4
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• pp.371-377
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• 2017

In this study, the heat dissipation performances of metal printed circuit boards (MPCBs) and flexible printed circuit boards (FPCBs) used in light-emitting diode (LED) lights were compared and analyzed by performing a heat dissipation simulation using a thermal flow analysis program. The results were summarized graphically. The temperature distribution of the MPCB was found to be better than that of the FPCB, indicating the better heat dissipation performance of the MPCB. For the two FPCB structures studied, we confirmed the LED temperature and temperature distribution by thermal flow analysis and found that for better overall heat dissipation performance, PCBs should preferably have an asymmetric structure. We confirmed the possibility of using FPCBs, which are characterized by a flexible structure, for LED lighting.

• Journal of Fisheries and Marine Sciences Education
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• v.29 no.2
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• pp.552-559
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• 2017

To assess the effect of LED lights on marine microalgae growth in the laboatory, Tetraselmis suecica, Chaetoceros simplex and Isochrysis galbana were cultured under $20{\pm}1^{\circ}C$, Walne's medium and aeration using 3.6 L glass vessels. The LED light sources were Blue, Red, Blue+Red, CoolWhite and WarmWhite. The experiments were conducted three times. The density of microalgae was shown as the counted number of cells per day, and the specific growth rate was calculated by using the density. The statistical analysis was performed by analysis of variance using the SPSS 20.0 program. T. suecica culture was the highest density under the Blue LED light source, so the light source was the most effective for the growth of this alga. C. simplex and I. galbana culture had the highest density under the Blue+Red LED light source, therefore this light source was the most effective for the growth of these algae. The result of analysis of variance showed significant between groups.

• KIEAE Journal
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• v.15 no.4
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• pp.21-28
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• 2015

Purpose: Although security lights are used to secure pedestrian visibility and safety at nighttime, they can generate light trespass in the neighboring residential space. To prevent this, standards for acceptance limits on vertical illuminance and light pollution by the windows of residential buildings are presented. Method: This study thus representatively selected three types of lamps and, through an evaluation and analysis of the physical and subjective discomfort glare per lamp, proposed a discomfort glare index for each lamp. The evaluation and analysis according to the lamps were conducted through experiments. The variables were the security lights' lamps (NH 100W, MH 70W, LED 50W), installation angles ($0^{\circ}$, $20^{\circ}$), and installation distances (3m, 5m, 7m, 9m). Result: According to the results of the discomfort glare evaluation depending on the angles and distances of the security lights, the following minimum standards are proposed: for NH 100W, a discomfort glare index of 30 and an installation distance of 4m; for MH 70W, a discomfort glare index of 32 and an installation distance of 4m; and, for LED 50W, a discomfort glare index of 31 and an installation distance of 6m, respectively. In addition, this paper recommends the use of MH 70W, when the road width is 4m-6m, and LED 50W, when the road width is over 6m, respectively.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2010.10a
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• pp.730-733
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• 2010

The Green Lamp Fixture (GLF) of LED prepared with thin panel structure was investigated for illumination of street lamps and other lighting system uses, which was also very useful to aquaculture and aquafarm lighting uses, or fish luring lights and marine aquanautics of aquamarinautics (aquamarine+aquanautics) uses, etc. In the case of fish luring lights, it was verified that the fish luring of Green Lamp Fixture of LED was very effective for phototaxis movement and ecological community promotion to the micro-living things of organisms and the small fries and fishes, like as 'crowding together'. For the aquaculture lightings, it was also very excellent in waterproof and heat-sink properties, photosynthetic growing of algae and micro-organisms, water-weeds and seaweeds living underwater.

• Journal of Institute of Control, Robotics and Systems
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• v.20 no.9
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• pp.984-993
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• 2014

In this paper, we propose a design for an efficient hybrid LED street lighting management system using standalone solar photovoltaic. The proposed efficient hybrid LED street lighting management system was composed of hybrid power conditioning system, gateways, LED street lights and a monitoring server. The hybrid power conditioning system was designed to charge produced power by solar photovoltaic panels in day time, and supply power to the LED street lights in night time. If there is insufficient power, the system was designed to operate using firm power, because the system utilizes photovoltaic power. A system control algorithm allied to the lighting management system, and experimented by being configured to the functions that are able to perform real-time monitoring and remote control through the lighting management system even when absent. In the result of the efficiency analysis of the hybrid lighting management system proposed in this paper, we were able to increase the energy efficiency compared to existing lighting control systems by reducing power consumption and electricity costs.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2008.10a
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• pp.101-104
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• 2008

This paper is a report of designing for LED lights driver unit. The main purpose of driver designing is high electrical efficient performance and intelligent control LED driver. This LED driver can be used for intelligent light control. This product expects to improve the light control by dimming instead of interlace on/off light control that increases the social cost such as car accidents and etc.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.1486-1492
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• 2011

The Development of science and technology began with the use of fire. In addition to the invention of an artificial light, more time and activity areas were provided so that continuous technological development has continued. Also, artificial lights brought an improvement in productivity through the applications in various fields such as agriculture, livestock farming, fisheries, and so on. Especially, in the field of agriculture, LED has come to the front as an alternative for food security against extreme climatic change. Meanwhile, with great interest, many researches about the convergence of agricultural biotechnology and LED industry are ongoing over the world. This paper shows the correlation of the plants growth using the LED artificial lighting similar to sunlight, which is needed for photosynthesis, in subway station which has actually no natural lights. Also, it is expected that this paper will lay out the groundwork for improving an environmentally friendly image which gives a relief and an emotional effect to passengers by using nature friendly lighting.

• Proceedings of the KSR Conference
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• 2006.11b
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• pp.885-889
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• 2006

Metro Subway System is widely known as the leader of public transportation in a metropolitan area. The signal interlocking is one of the most important organs that plays a major role in the system. By improving the quality of signal lights on the traffic system and keeping its maintenance on a high level will not only repair the current state, but it will also let the LED type signal semi-permanent. The device, which underwent a process of fine manufacture establishment and a close examination, obtained a patented article (2004, as a new device). Utilizing the equipment with cautious preservation on the system will enhance the current state of the signal device. Especially, the test for improvement and development based upon the technique that decreases the frequency of defect produced will further precipitate its efficiency. With authorization of imposing the LED lights on production, installment, and investigation of the system, the newly made equipment will bring improvement to the signal technology and to the industry at largest extent.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.1
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• pp.233-239
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• 2015

The demand of remote control and monitoring for efficiency and applications of LED streetlight is increasing continuously because the demand of LED streetlight was increase last few years. Existing street light remote control system is wired using a power line network. The wireless connection exists, but due to its low data transmission rate, it cannot support specialized applications. It can only support simple control and monitoring. In this paper, we propose a system that uses a IEEE 802.11s wireless mesh network based on WLAN, as a backbone network for remote control and monitoring of the LED street lights along with other specialized applications. Using the wireless mesh network for remote control and monitoring the LED street lights, the same can be used to act like a public Wi-Fi access point. We have designed Wi-Fi integrated LED streetlight controller and implemented our system. We evaluated the performance of our system on a real test bed. Our proposed system is expected to perform the role of a U-city infrastructure by utilizing the wireless mesh network.

• International Journal of Advanced Culture Technology
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• v.4 no.4
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• pp.6-12
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• 2016

Due to the development of technology, the modern people became to require not only more convenient life but also more comfortable and emotional environment, and individually suitable living environment is applied to residents in a residential space. Recently, while the LED lighting was variously attempted in every sector in society, it is needed to express differentiated lighting according to the resident's individual lifestyle in a residential space. In this paper, we analyze the role of LED lighting suitable for the digitalized lifestyle of the modern people through the relevant literature survey and case studies. The following results are obtained in summary of the rapidly changed recent trends of LED lighting. First, LED light replace existing light sources due to the advanced new technology in LED industry, and take the spotlight as a new lighting solution with the development of variable color LED bulb and the control technology by the wired and wireless communications. Second, LED lighting can be structurally applicable to every lighting device because of its compact and lightweight units, can produce abundant light environment by expression of variable colors and moods with the easy coloring and dimming control, can be reborn as emotional lighting design. Third, as recently practices are constantly appeared that integrate LED lights in the interior elements, such as object and furniture, and combine advanced LED lighting technology to new materials, the portion of illumination on the indoor environment is further increased after integrating the LED lighting and interior elements make boundaries of lighting and product architecture become blurred. LED lighting is confirmed that is being changed from the external functionality including material, shape, color, and etc. into the contextual emotion design including the lights expression, variable color, brightness control, making image, and etc. as the light source in current smart lighting era.