• Proceedings of the Korean Society of Precision Engineering Conference
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• 2009.06a
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• pp.373-374
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• 2009

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2009.05a
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• pp.190-192
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• 2009

LED를 광원으로 사용하는 조명기구는 용도에 맞는 적합한 배광을 가져야 한다. LED 조명기구의 배광을 달성하는 LED 2차 렌즈의 설계를 위해서는 LED의 기본 배광이 고려되어야 하며 일반적으로 기본 배광은 LED 돔의 형태에 따라 달라진다. 일반적으로 사용되는 램버시안 배광을 갖는 LED를 기본으로 하여 돔 형태 및 기본배광이 다른 각각의 LED에 대한 2차 렌즈를 설계하고 시뮬레이션을 통해 그 성능을 평가하였다.

• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.1316-1318
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• 2009

Nonideality of LED lens and diffuser as well as crosstalk between backlights should be compensated because they have large effects on image qualities. The computation complexities of conventional compensations are greatly increased as resolution becomes higher. The block based compensation is proposed to alleviate the computation complexity considering backlight profiles and image pixel characteristics.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.23 no.6
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• pp.471-476
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• 2010

This paper has studied dissymmetrical light distribution design using the secondary optics in the simulation. fundamental Lambertian radiation distribution based on LED has been cut off by the secondary optics, and the first surface slope of lens and second surface slope of total reflection area have been calculated through formula. PMMA (the index of refraction: 1.49361) which is material of lens has been selected. critical angle($42.02993^{\circ}$) between Air and PMMA has been calulated by snell's law, and total reflection angle slope has been selected about $16.67^{\circ}$ to occur the total reflection. when the first surface slope and the second surface slope has been set up, Rays of all total reflection area have generated the total reflection. finally, designed LED Module has been estimated by Korean Industrial Standards for LED safety street lighting. dissymmetrical light distribution have been analyzed with reached effect of road illuminance, and average road illuminance which are each 70.6 lx, 40.35 lx, and 25.88 lx have been satisfied with Korean Industrial Standards for LED safety street lighting.

• Biomolecules & Therapeutics
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• v.10 no.2
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• pp.85-88
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• 2002

Systematic fractionation of Angelica gigas roots led to the isolation of linear coumarins such as decursinol angelate, decursin and nodakenin. These compounds were tested for their effects on rat lens aldose reductase. Nodakenin was demonstrated to exhibit significant inhibition of rat lens aldose reductase activity with $IC_{50}$ value of $7.33\Mu\textrm{M}$.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.6
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• pp.1178-1182
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• 2011

The best methods for distribution controled of LED lighting fixtures is control to designed LED chip array, lens and reflector. However, lens design need distribution design to reflector for low-wattage LED lighting because of difficulty of production and reduction of light efficiency. In addition, it needs maximize of thermal performance to improve the efficiency and reliability of device. As a result, for the height of reflector 40[mm] and Inclination 25[$^{\circ}$], we can see the best distribution properties, and, in the thermal properties, junction temperature MCPCB 62.9 [$^{\circ}C$], FR4 PCB 89.6 [$^{\circ}C$], FR4 PCB from Via-hole is 63.1 [$^{\circ}C$]. it may improve for thermal properties for makes the Via-hole.

• Journal of the Institute of Electronics and Information Engineers
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• v.53 no.5
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• pp.37-46
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• 2016

In this paper, we propose the beam-steering system using Rotman lens antenna operating at 2.442GHz which is to replace an expensive phase shifter. The overall system consists of the transmission antennas, Rotman lens and switch box. Setting the initial design conditions, it was designed and fabricated satisfying the requirements. From the result tested in the anechoic chamber, it was found that the beam can be steered using Rotman lens in the anechoic chamber. We also visually checked the beam-steering by turning on the LED of the rectenna showing the real-time beam receiving.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.29 no.1
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• pp.62-67
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• 2016

In this paper, the IES file was measured by applying a secondary optical lens to a 21 W LED engine, and the lighting calculation software RELUX was used to perform simulations with the data file of this measurement. For two-lane (two way) concrete paved roads, six LED engine are applied to each streetlight and simulation results show that Uo (uniformity) 0.56, UI (longitudinal uniformity) 0.86 and TI (threshold iIncrement) 9% which satisfies the required standards. RELUX was also used to LED streetlights by designing them in three dimensions, that is ${\pm}25%$ of the arm length of 2.8 m standardized by the road lighting standards of the Korea Expressway Corporation. Comparative analysis was carried out on adjustments were made in increments of 0.1 m that Uo, UI, and TI values in the range of arm lengths from 2.1 m~3.5 m. For the arm length range of 2.1 m~2.4 m, Uo was high, whereas UI was low. Therefore, we present the optimal light distribution values designed for an arm length of 2.5 m.

• Journal of the Korean Society for Precision Engineering
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• v.25 no.2
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• pp.43-48
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• 2008

This paper proposes a new method for measuring the power of spherical and cylindrical lens with 6 points light source, which is composed of a LED and six holes, and magnification ellipse fitting algorithm. Each measured diagonal length of 6 points light source is determined by the target lens power. After finding the center position of each light point with threshold method, 3 axis-diagonal lengths were calculated. The long axis and short axis power of cylindrical lens can be calculated by using magnification ellipse fitting algorithm with the magnification relationships between the initial diagonal lengths and the measured diagonal lengths changed by lens power.

• Proceedings of the Optical Society of Korea Conference
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• 2007.02a
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• pp.299-300
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• 2007