• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.35 no.6
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• pp.562-567
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• 2022

Novel self-illuminated smart windows were fabricated consisting of Cu-doped ZnS (ZnS:Cu) powder and polymer-dispersed liquid crystal (PDLC). This smart window shows not only switchable transparency but also self-illumination without any attachable luminous body. Its electro-optical characteristics, transmittance, and luminance were investigated in relation to various applied voltages and composition ratios. The optical transmittance and luminous intensity increased with increasing applied voltages. However, the optical transmittance decreased with increasing ZnS:Cu powder content. One of the self-illuminated smart windows, which was fabricated with 9 wt% of ZnS:Cu, achieved the optical transmittance of 60.5% (at 550 nm) and the luminance of 11.0 cd/m² at 100 V. This smart window could be used as a normal switchable smart window in daytime and light-emitting signage at night.

• 한국정보디스플레이학회:학술대회논문집
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• 2005.07b
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• pp.1221-1224
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• 2005

The improvement of luminance and luminous efficiency is the one of the most important parts in AC-PDPs. To achieve high luminance and luminous efficiency, high VUV emission efficiency is needed. We measured the emission spectra of the vacuum ultraviolet(VUV) rays in surface discharge AC-PDP with ternary gas mixture of He-Ne-Xe. The influence of He-Ne-Xe gas-mixture ratio on excited $Xe^{\ast}$ resonant atoms and $Xe_2\;^{\ast}$ dimers has been investigated. It is found that luminous efficiency of ternary gas mixture, He-Ne-Xe, is shown to be much higher than that of binary gas mixture of Ne-Xe. For improving discharge luminous efficiency, we have studied VUV emission characteristics of ternary gas mixture, He(50%)-Ne-Xe and He(70%)-Ne-Xe with Xe concentration and filling gas pressure.

• Korean Institute of Interior Design Journal
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• v.22 no.4
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• pp.86-93
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• 2013

Illumination in church building has played an important role in making workship space more suitable for divine service. As time has changed, however, the worship space of Protestantism is no longer somber and reverent, but changing into practical and multipurpose space with bright and colorful image. This study investigates intensity of illumination of worship space during day and night respectively and figures out the change of psychological change of congregation in accordance with brightness and color temperature in worship space in order to find out preference and look into the usage and change of illumination in recent Protestantism in compliance with the needs of the time and influence. Then, result value is to be compared to Korean Standard intensity of illumination. Also, the correlation between intensity of illumination and color temperature by Kruithof's curve theory is used to identify the comfortableness of the worship space during day and nigh. And it is a common task of space designers and pastors to map out the worship space in terms of illumination suitable for its own purpose with even more modern and Korean sensibility and to create spiritual space for worshippers by collecting opinions from congregation, the main user of the space. With appropriate usage of illumination in Protestantism worship space, the atmosphere and purpose of worship can be enhanced.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.11B
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• pp.1383-1388
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• 2011

Due to many recent activities on enforcement of the intensified environmental regulation such as the policies of curbing the greenhouse gas and the Restriction of Hazardous Substances (RoHS), the usage of Light emitting diode (LED) has been rapidly increased and energy efficient management of LED light system is regarded as an important technology to enhance the energy efficiency. In this paper, we propose an energy-efficient control scheme of LED light, being composed of multiple light sources. The proposed scheme controls the intensity of LED light source to minimize the total intensity while providing the quality of lighting service. The intensity of light is assumed to be proportional to power consumption, thus the objective is to minimize the total power consumption. A linear programming problem is formulated to find the optimal intensity of each light source and procedure to apply the proposed scheme in the real system is suggested. The performance evaluation results elucidate that the proposed scheme achieves over 20% improvement in power consumption of light intensity in comparison with the conventional dimming control scheme.

• Journal of Advanced Marine Engineering and Technology
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• v.38 no.6
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• pp.737-743
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• 2014

This paper dealt with a retrofit high power LED searchlight to replace conventional 1kW halogen searchlights. The design specification meets KDS 6230-1046-1 and KS V 8469. An optical lens with the beam angle of $6^{\circ}$ was used to meet the luminous intensity of 800,000cd at $0^{\circ}$ in horizontal line. Heat dissipation of the LED searchlight adopted a free air cooling type which does not use a fan or a heat-pipe. From the test results, power consumption of the prototype LED searchlight was 148W which was saved by 85% comparing a halogen searchlight of 1kW. Luminous intensity was 945,000cd at $0^{\circ}$ in horizontal line, satisfying KS V 8469. Luminous efficacy was improved by 4.7 times higher than that of the halogen searchlights. Beam angle, color temperature, and color rendering index(CRI) was $5.4^{\circ}$, 5,500K, and 70, respectively. Surface temperature of the LED searchlight was below $60^{\circ}C$ and surrounding temperature of the SMPS installed inside was below $50^{\circ}C$ which were satisfied with the IEC 60092-306.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2002.11a
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• pp.71-75
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• 2002

The prismatic luminaire named as a dome pendent is considered to save energy and improve visibility. This luminaire is using prismatic rome, and is designed to be used in commercial and industrial high-bay applications where quality light levels and energy savings are imperative. Although this kind of luminaire needs an accurate optic calculation process, the lumanires are manufactured without such a process. Therefore the purpose of this study is to develop a numerical model to accurately predict luminous intensity distribution of luminaire with prism.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2009.10a
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• pp.137-140
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• 2009

본 논문에서는 반사판을 이용하여 LED 보안등기구의 배광을 제어하였다. 먼저, 광학 설계를 용이하게 하기 위하여 집적화된 LED 모듈의 적정 배열을 도출한 후 반사판 설계를 하였으며, 광학 성능 예측 프로그램을 이용하여 결과물의 성능을 확인하였다.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2002.11a
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• pp.3-8
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• 2002

In this paper, We measured an electric and optical characteristics for electrodeless fluorescent lamp system. We used the CCD(charged couple device) and Integrating Sphere Photometer to detect the accurate variation of data and got a characteristic of output voltage and current, luminance, luminous flux etc. And then we come to understand that the efficiency of electrodeless fluorescent lamps are similar to CFLs(compact fluorescent lamp) or HID(high intensity discharge lamp).

• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.20-23
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• 2009

The efficacy improvement issues in a unit discharge cell have been approached from the structural considerations. The tested cell designs include (a) a coplanar type with annular auxiliary electrode buried in barrier ribs, (b) a coplanar type with split auxiliary electrodes also burred in barrier ribs and (c) a coaxial type with a floating electrode stacked on the base electrode. From spatiotemporally resolved optical images of near-IR emission taken by a gated-ICCD camera and relative VUV emission intensity estimated by laser absorption spectroscopy, the differences in the discharge and light emission performances of those three cell types have been compared and discussed.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.29B no.1
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• pp.67-75
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• 1992

A new method of driving the PDP(Plasma Display Panel) was proposed and its characteristics were investigated. Applying high frequency non-discharge pulses to an auxiliary anode resulted an increased region of stable operation, decreased delay time and increased light intensity. It is suggested that PDP with DPM (Double Pulse Memory) drive technique improves the delay time, luminance, region of stable operation and luminous efficacy compared to PDP with PPM(Planar Pulse Memory) drive technique developed by NHK Lab. in Japan.