• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.29 no.1
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• pp.31-36
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• 2015

In this paper, an LED lighting system that is capable of automatic or maunal dimming control using a ultrasonic sensor and Bluetooth wireless communication technology is presented. The LED lighting system consists of a ultrasonic sensor, microcontroller unit, Bluetooth wireless communication, LED driver, and LED light source. By using the implemented LED lighting system sample, it is shown that the automatic and manual dimming control is realized. By using the ultrasonic sensor, the LED lighting is automatically brighter or dimmer depending on the distance between the sensor and an object. When using a smartphone that includes Bluetooth wireless communication function, one can not only manually control the brightness of the LED lighting from level 1 to 10, but also monitor the distance between the sensor and object on the smartphone.

• Journal of the Korean Solar Energy Society
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• v.24 no.4
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• pp.1-10
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• 2004

In view of global environmental problems and resource exhaustion, we must develop new energy resources that are abundant and provide substitutes for fossil fuels. Renewable energies, such as solar, are ideal because they are clean, inexhaustible, and available everywhere in the world. Photovoltaic(PV) system, in general, are operated as a stand-alone, grid-tied, or hybrid system. Many of the stand-alone PV systems are installed. Although the pre-installation cost of PV system is high, it poorly has been operated due to the absence of optimal management standards. Therefore a study on the performance of PV system is important for the system design and maintenance. In this paper a photovoltaic lighting system was resigned according to load consumption. Then a PV lighting system which used electrodeless lamp as a load was installed. In order to investigate the system operating characteristics we've added a monitoring system to the PV lighting system. The monitoring system using the LabVIEW program regularly checks the operation of the PV lighting system and records the system data. According to the system data, the stability and availability of the PV lighting system were evaluated.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.17 no.1
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• pp.23-33
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• 2018

In the general manual feeder of an LED lighting assembly system, many workers are needed to supply parts to the main conveyor. The automatic feeder for modern automation lighting assembly systems consists of a completely automated feeding system and a magazine system that supplies the parts automatically. A standardized LED panel and diffusion cover is stacked in the cartridge of the magazine system. The structural safety of the automatic feeding system with regard to handling the load from the panels and covers stored in the cartridge should be guaranteed. LED convergency lighting modules are assembled using two LED panels and one diffusion cover in an automatic feeder. In this study, the structural safety and fatigue life of the automatic feeder and magazine were analyzed by considering the load generated in the automatically assembled LED convergency lighting system. In addition, the dynamic behavior of each auto-feeding system and magazine delivery system was visualized, and the working process was evaluated via dynamic simulation using a virtual engineering method. A tack time table for automatic feeding systems was derived by developing a virtual prototype.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.29 no.9
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• pp.1-9
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• 2015

The aim of this study is to deduce color temperature and illuminance by conducting the preference & affective evaluation consequent on illuminance change of ambient light in case of the lighting method of ambient light mixed with task light in time of reading which is visual work action among the action in learning space. As a result of the prior survey on preferred lighting method in time of the act of reading targeting 20 experts before doing evaluation, the method of lighting mixed with ambient light and task light was found to be the highest. Such a result is analyzed to be attributable to the fact that the less the difference in illuminance of nearby space and work surface because of the mixed method of lighting, the less the glare, which makes a reader feels easy and concentrate on reading. On the basis of descriptive statistics of evaluation results and impact analysis by category, this study recommends the application of combinations of ambient light illuminance ranging from 40lx to 100lx with color temperature of 5500~6000K in case of the method of lighting mixed with general light and task light.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.22 no.3
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• pp.429-436
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• 2013

In this study, we researched a pendant-type aspherical optical system, which could be applied to street lighting and security lighting in Europe. The goal of this research was eco-friendly artificial lighting that could be used for the one-to-one replacement of ordinary lighting. LED lighting was miniaturized by using one COB LED Module and one aspherical optical system, which could control the luminosity of the LED. Through the aspherical optical system, the light distribution angle could be controlled in a range of $140^{\circ}$ for the X-axis and $40^{\circ}$ for the Y-axis. This means that this optical system is appropriate for catenary-type lighting, which is widely used in Europe on both narrow and broad roads. The performance was determined using a lighting simulation program. This lighting system simulation showed that road rates M4 and M5 could be satisfied, with the condition of a 13-m height and 50-m distance (U0 and TI). The simulation program estimated that light pollution, which disturbs sleep, could beeliminated in the European streetlight case. Determining methods for the light distribution control, performance, and optimal lighting setup conditions is very important to prevent light pollution. Moreover, the initial step of developing the lighting system design and post management will require an effort with much analysis.

• International Journal of Highway Engineering
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• v.14 no.6
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• pp.111-120
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• 2012

PURPOSES : This study is to suggest suitable lighting facility installation plans by finding out driver's preference for combination of lighting facility installation among landscape factors that affect driver visibility in tunnels. METHODS : SD method is used to extract emotional factors that affect drivers' preference, Components of tunnel lighting facility installation are evaluated through conjoint analysis and it suggested relative importance of attributes and utility values. RESULTS : In the aspects of satisfaction levels of components of tunnel lighting facility installation, Tunnel side, two lows, and solid line arrangement type has the highest level of satisfaction. Extract emotional factors that affect drivers' preference are "safety", "openness" and "amenity." In addition, the result of analyzing relative importance of attributes of tunnel lighting facility shows that numbers of lighting array has the highest importance and lighting facility arrangement has the lowest importance. Result of analyzing partial utility shows that the 2 low type among number of lows, the solid line arrangement type between arrangement types, placing in the middle part among lighting facility arrangement were highly preferred. CONCLUSIONS : In the case of lighting numbers, utility values of the first line and the second line showed us a big difference. Increasing the number arrays in the future reformation of lighting facility installation combination will be effective in enhancing the utility of the driver.

• Proceedings of the KIPE Conference
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• 2018.07a
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• pp.522-524
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• 2018

A New Direct AC LED Driver has been proposed for wide output power range and precise constant current regulation using an advanced auto commutation topology. The conventional shunt regulation method provides a stepped input current shape by fixed regulation references in the linear regulator of the each channel, which results in poor current regulation and high THD. The conventional method needs to assign a linear regulator in each LED channel so that the number of linear regulator increases when extending the number of channels especially at high power application. The proposed regulation method can drive multiple switches to regulate each LED channel current by a single amplifier with sinusoidal reference so that large number of LED channel can be simply extended with less BOM cost and low THD is obtained with the accurate current regulation thanks to the sinusoidal input current control in the closed loop control. To confirm the validity of the proposed circuit, theoretical analysis and experimental results from a 20-W LED driver prototype are presented.

• 한국정보디스플레이학회:학술대회논문집
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• 2008.10a
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• pp.1347-1348
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• 2008

The efficacy and its degradation of light emitting diode(LED) are related to its PN junction's temperature(Tj). Currently efficacy in certain temperature and thermo-resistant are defined for the depending. However, the definitions are quite inconvenient for lighting application. The paper focuses on the issue and presents a method to evaluate the thermal characteristics of LED efficay.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.27 no.2
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• pp.7-13
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• 2013

The portion of lighting power consumption for our country is up to 20~30% of the total amount. Currently, most of the DSM(Demand side management) of lighting power is delivered in supply of high efficient lighting to customers. On the contrary, applications of lighting power to power load leveling are still rare. In this paper, the simulations for various control types of lighting power for load leveling are tried, and we obtained the cost effective and optimal control method through that. This simulation was executed in test office with fluorescent light by us based on applying 8 control types(on, off & dimming), considering customers' satisfaction, for instance, minimum intensity of illumination allowed. According to the result of this test, we found that mixed type(chessboard(on-off) plus dimming control(10%)) is most effective.

• Journal of Applied Reliability
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• v.10 no.1
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• pp.11-24
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• 2010

Lighting industry is rapidly being developed as the ubiquitous society based on sensor network emerges. This kind of paradigm shift brings the society convergence of technologies which leads to smart lighting system as well as the integration of interior and sensibility control. However, standards for sensors have not been firmly established, and problems related to quality and malfunction have been brought up, thereby calling for careful approach to the enhancement and assessment of reliability of the item. In this article reliability assessment criteria for sensor module for lighting fixtures is established in terms of performance assessment criterion and reliability assessment criterion.