• Journal of electromagnetic engineering and science
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• 제1권1호
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• pp.88-94
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• 2001

In this paper, the lightning-induced voltages on shielded twisted-pair wires with multipoint grounding on cable sheath are calculated by using finite-difference time domain (FDTD) method. The equivalent single-wire line that represents a bundle of twisted-pair wires is adopted for computational efficiency. A finitely conducting ground is also taken into account in both lightning electromagnetic field calculations and surge propagation along the shielded cable for a practical simulation. It is found that multipoint additional grounding on cable sheath provides more shielding effectiveness especially in the early time response of the lightning-induced voltages. From this study, the requirements for lighting surge protection devices in a telecommunication subscriber cab1e can be established.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2007년도 7th International Meeting on Information Display 제7권1호
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• pp.431-434
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• 2007

Rapid progress has been made in the development of commercially viable Light Emitting Polymer (LEP) materials for display and lighting applications. This presentation will focus on: ${\bullet}$ Degradation studies that have led to the design of new and improved materials ${\bullet}$ Recent lifetime and efficiency results for red, green, blue, and white polymers ${\bullet}$ Challenges of formulating inks that can be used in a production environment

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제55권1호
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• pp.50-54
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• 2006

The study on discharge of the flat lamp lighting source has been requested increasingly. To improve the brightness, life time and efficiency of flat lamp, the plasma diagnosis of flat lamp lighting source is very important. When a distance of discharge electrode is 5.5mm and width is 16.5mm, we measured electron temperature and electron density with single Langmuir probe in flat lamp. Pressure conditions to test the plasma discharge from 100 Torr to 300 Torr. The power supply was PDS-4000 with frequency 20kHz and duty ratio $20\%.$ Form these experimental results, electron temperature was decreased according to increase the gas pressure and the voltage while electron density was increased.

• Transactions on Electrical and Electronic Materials
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• 제17권1호
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• pp.41-45
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• 2016

The Cs₃Sb photocathode was formed by non-vacuum process technology and successive in-situ photocathode vacuum device fabrication carried out in a process chamber. Performance testing of the device was followed. Light emission from the devices was induced by photoemitted electrons, which were accelerated by an anode electric field that was shielded from the photoemitter surface. The luminescent characteristics of the devices were investigated by measuring the optical parameters as functions of the applied anode voltages. The results showed that this approach could produce a more easily directed and controlled stream of light. These features make these devices suitable for a variety of planar lighting applications.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 추계학술대회 논문집 전기물성,응용부문
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• pp.306-309
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• 2004

Recently, the environmental problem has received considerable attention. so, many lamps have been developing for environmental requirement and energy efficiency. also, at glow discharge lamp researchers try to reduce energy spending that is power saving lamp. this kind requirement agree with strong points of electrodeless fluorescent lamp has received to now lighting sauce. At low pressure as mTorr I.C.P make high density plasma easily, is good to maintain discharge, has high ionization and does not have failing lighting and losing ability of electron radiation by oxidation and volatilization of electrodes, because this tape does not have electrodes. This point of I.C.P can use at electrodeless fluorescent lamp in this study ICP display elements and Ar, Ne, Kr are researched for optical characteristic. each gas is looked into optical characteristic, also mixed gases is experiment for optical characteristic.

• KIEAE Journal
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• 제17권3호
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• pp.91-97
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• 2017

Purpose: Various studies on a light shelf are in progress, but it has the problem of glare occurrence. The present study suggested a diffusion film as the method for resolving the glare problem, and aimed to establish light shelf-related basic data by conducting the performance evaluation of a light shelf depending on the installation position of the diffusion film. Method: To carry out the light shelf performance evaluation depending on the diffusion film installation position, three cases were established: no diffusion film installation (Case 1), diffusion film installation on the reflector (Case 2), and diffusion film installation on the upper glass surface of the window for light shelf installation (Case 3); and the energy reduction performance, luminance, and luminance contrast were analyzed based on a testbed. Result: The conclusions of this study are as follows. 1) When the diffusion film was applied, the amount of light introduced through the light shelf decreased, and the average indoor illumination decreased accordingly. 2) For Case 3, the lighting energy reduction performance was identical to the lighting energy reduction efficiency of the existing light shelf; and for Case 2, it was found to be inappropriate as the lighting energy consumption increased compared to that of the existing light shelf. 3) The analysis of the glare for the cases established in this study showed that the luminance contrast was low for Case 3, and thus the glare problem could be minimized. 4) The specific angle of the light shelf could induce the glare problem by increasing the luminance depending on the external condition. 5) Based on the aforementioned contents, the installation position of the diffusion film for improving the lighting performance and glare problem of the light shelf was found to be the upper glass surface of the window for light shelf installation.

• 설비공학논문집
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• 제27권8호
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• pp.395-401
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• 2015

Recently, many research studies have been carried out on the efficiency of light-shelf daylighting systems, especially comparing performance improvements and the limitations of reflective surfaces and their lighting performance. In this study, a crystal face reflective surface is proposed. The objective of the study is to evaluate the lighting performance of a crystal face light-shelf through a performance study. The performance study was carried out in a full scale test-bed in order to calculate the light distribution and energy consumption utilizing the standard indoor illumination as an index. The conclusions of the performance study are as follows. 1) The optimal angle of incidence for daylighting for both the operable flat type light-shelf and the crystal face light-shelf are taken in the natural environment on the dates of the winter and summer solstices, as well as the autumn and spring equinoxes. 2) The application and installation of the crystal face light-shelf can produce a 29.9%~34.3% increase of light distribution within the indoor space. However, the increase of light distribution can also lead to a decrease in the uniformity ratio, a design challenge that should be considered when applying a crystal face light-shelf. 3) It is possible to achieve a 7.98%~13.3% greater reduction in energy consumption when applying a crystal face light-shelf than when applying a flat type light-shelf. The increase in the number of crystal faces should concur with the analysis of the energy reduction. A limitation of the study is that only one predetermined pattern was performance tested for a crystal face light-shelf. In order to carry out further research on crystal face light-shelves, additional performance studies are needed based on alternative patterns and designs.

• 조명전기설비학회논문지
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• 제27권3호
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• pp.16-25
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• 2013

Now it's a trend to install a series of white fluorescent light and orange high pressure sodium lamps because tunnel lighting should be opaque to the safety of drivers from soot, dust, humidity, and fog. Also fluorescent lighting is replaced to LED due to the fact that it improves amenity and object recognition and LED lighting has gradually been improved its nature. In this paper, we have implemented the circuits of the yellow series of high-pressure sodium lamps and white series of LED lights at one board to improve the transparency and recognition of objects. It is possible for inductive high-pressure sodium lamps and the capacitive LED drivers to circuit without power factor compensation. Two circuit parts share only a small number of parts, so low cost LED drivers compared to conventional ones are possible. Therefore, the implementation of the hybrid lighting with high-pressure sodium lamps and LED lights that can be driven at the same time by one driving circuit is possible. The LED capacitive power factor was 0.91 while individually implemented the sodium lamp power factor was 0.98. It shows not only the 2% improvement of hybrid forms but also the efficiency and THD.

• 한국산학기술학회논문지
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• 제16권5호
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• pp.3579-3586
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• 2015

본 논문은 온도 $25[^{\circ}C]$, 상대습도 50[RH%], 조도 1,000[lux] 및 기류 속도 0.02[m/sec]의 동일한 조건의 항온 항습실에서 감각자극에 노출되기 전, 쟈스민 향기 및 RED 조명의 단일감각자극, 쟈스민 향기와 RED 조명을 동시에 노출시킨 다감각 자극 변화에 따른 EEG, 학습능력, HRV 및 진동이미지를 측정하여 쾌적성, 집중력, 신체적 및 심리적 안정의 변화를 분석하였다. 연구결과 쟈스민 향기와 RED 조명의 다감각자극에서 상대 $S{\alpha}$파, SEF50, $SMR/{\theta}$ 및 SDNN이 향상되었고, 비대칭지수 $A_2$, 스트레스지수, 피로도 및 HRT는 감소하였다. 또한, 진동이미지의 긴장/불안과 스트레스는 감소하였다. 따라서 쟈스민 향기와 RED 조명의 다감각자극이 쾌적성, 작업능률의 생산성 및 주의집중력과 같은 뉴로에너지를 향상시키기 위하여 효과적인 것을 알 수 있었다.

• 조명전기설비학회논문지
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• 제23권12호
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• pp.176-183
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• 2009

대형병원의 에너지 소비패턴을 분석한 후 마이크로가스터빈을 적용할 경우 기존 시스템 대비 냉난방에너지 절감량 및 전기에너지 절감량과 경제성분석을 통해 대형병원의 에너지 소비량을 절감하기 위한 에너지성능평가 모의연구를 수행하였다. 0.5[MW]급 마이크로 가스터빈을 설치한 후 에너지 성능분석을 한 결과 터빈에서의 발전효율은 30[%]이며, 전기는 건물에서 사용되는 조명에너지 뿐만 아니라 전체 전기에너지의 40[%]을 절감할 수 있는 것으로 분석되었다. 또한 터빈에서 발전되는 전기량과 배열을 냉난방에너지원으로 이용할 경우 전체 시스템효율은 70[%]로 상승할 뿐만 아니라 난방에너지의 56[%], 냉방에너지의 67[%]를 절감할 수 있는 것으로 분석되었으며 현가등가법에 의한 시스템 투자회수 기간이 약 9년으로 분석되었다.