• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.23 no.4
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• pp.1-7
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• 2009

This study investigated the actual conditions of the illumination environment from agricultural youth study room. The result, average space of the study room was 11.42[$m^2$]. The illuminant uses the fluorescent lamp mainly, Method of using illumination was only general illumination the case which uses 73.8[%]. Method of light distribution was a direct lighting mainly. The house which has a stand illumination was also 45.7[%], The percentage using the stand illumination which was a local illumination was nothing but in 20[%] of the whole subject of investigation, therefore eye work could not effective. The internal illuminance was average 131.82[lx], the desk illuminance was 253.64[lx] which was the minimum permitted limit and poor. Uniformity ratio of illuminance appeared with average 35.61[%]. The satisfaction with 3.93 points to be high for illumination environment, therefore it was thought that the recognition of illumination was very insufficient.

• Journal of Advanced Marine Engineering and Technology
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• v.35 no.5
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• pp.654-660
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• 2011

This paper dealt with a design guide of LED luminaires to replace the surface and watertight fluorescent lamp (FL) fixtures for naval vessels. Several standards such as Korean Industrial Standard (KS), Korea Defence Standard (KDS) and US Military Standard (MIL) were compared in terms of safety and performance of lighting fixtures. The electrical and optical characteristics like power consumption, total luminous flux, and illumination distribution of the FL fixtures were experimentally analyzed to acquire design rules for LED luminaires. Based on the results, four types of LED luminaires were fabricated, and we proposed a design guide of LED luminaires for naval vessels which save power consumption of 44~51 [%] and increase total luminous flux of 8~13 [%].

• Journal of Mushroom
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• v.12 no.4
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• pp.258-262
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• 2014

We aim to elucidate suitable mixed color of light during development of fruit body in Pleurotus ostreatus. The four mixed color of LED(Light Emitting Diode), blue and white, green and white, blue and green and green and red LED, were irradiated for formation of fruit-body. First, as effect of mixed color of LED, the properties of fruit body of P. ostreatus in blue and white LED irradiation were showed higher commercial yields than those in control(fluorescent lamp). And the ergothioneine was the highest at the blue and white LED. Second, we could obtain higher commercial yields than those at the $1{\mu}mol/m^2/s$ of light intensity by blue and white LED in P. ostreatus.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.1
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• pp.390-395
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• 2011

In order to develope piezoelectric transformer for the ballast of fluorescent lamp, the composition of piezoelectric ceramics was 0.95Pb($Zr_xTi_{1-x}$)O3+yPb($Mn_{1/3}Nb_{2/3}$)$O_3$+(0.05-y)Pb($Sb_{1/2}Nb_{1/2}$)$O_3$. PMN compound was selected to improve mechanical quality factor and PSN to prevent the decrease of dielectric constant and electromechanical coupling coefficient. Dielectric and piezoelectric characteristics in the region of MPB of 0.95Pb($Zr_xTi_{1-x}$)$O_3$+yPb($Mn_{1/3}Nb_{2/3}$)$O_3$+(0.05-y)Pb($Sb_{1/2}Nb_{1/2}$)$O_3$ ceramics was discussed both quantatively and qualitatively.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2017.11a
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• pp.220-221
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• 2017

The initial light emitting diode (LED) has been used as a display device for various mechanical devices due to its low power. The development of LED technology has made it possible to express color with high power and high brightness. Therefore, it is used as a display such as a traffic signal, a large electric signboard, and an automobile display, and is also adapted as an indoor or outdoor light source such as an incandescent or a fluorescent lamp which requires the high luminance. The bulb of marine lantern, which is used for the aids to navigation, was replaced to LED. The first marine LED lantern was manufactured using multiple LEDs. However, if the optical design is renewed by the development of LED or even if a few LEDs are used, it is possible to satisfy the brightness and the light distribution required by the marine LED lantern.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.48 no.5
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• pp.1-6
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• 2011

LED(Light Emitting Diode) components have advantages of longer lifetime, lower power consumption and easy-to-control, compare to normal lamp and fluorescent light, according to the development of recent technologies. Thus, lots of illuminations which utilize LED components could be used. Recently, Visible Light Communication(VLC) which is a part of communication technologies, utilizing high speed response characteristic of LED components, started receiving public attention. In case of VLC, there is no need of frequency allocation due to no use of radio, but also no interference exists during data transmission, much different in ISM((Industrial Scientific Medical band). This is the reason why a lot of research results about VLC are becoming issued. In this paper, a survey of feasibility for using VLC utilizing an original LED illumination for underwater applications has been done and a primitive possibility of its application has been examined.

• Korean journal of applied entomology
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• v.10 no.1
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• pp.43-48
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• 1971

This experiment was conducted to determine the most effective type of Bight·trap for pine catepillar moths (Dendrolimus spectabilis B.) and to investigate the environmental factors affecting the attractiveness of the moths.. The various types of light traps made used of: black light, white light, fluorescent light, yellow light, and red light and the environmental factors considered were rainfall, wind velocity and collecting time. All the traps were operated from 8 in the evening to midnight. The results obtained are summarized as follows; The most effective attraction of moths ($62\%$ of total number attracted) was observed with blacklight-lamp and the most abundant attraction of the moths was found from 8 to 10 in the evening. Attractiveness in terms of sex ratio attracted from 8 to 10 in the evening was found to the .approximately 7 female to 1 male, Environmental factors considered were found to have no influences in attractiveness of the moths in this experiment.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.14 no.1
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• pp.23-30
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• 2014

Recently, Light Emitting Diode(LED) light is changing the light equipment, which was considered just as a power-controlled device in home-network, into a IT convergence device by combining illumination function with wireless communication. As a result, Visible Light Communication(VLC) becomes a more practical solution to ubiquitous networks due to the more spread of LED light. One of representative applications using VLC is a VLC-based indoor navigation system which can provide high-accuracy indoor localization. In this paper, we model and implement a VLC based-indoor navigation system in which a fluorescent light type of LED lamp, which is normally used in large buildings, and smart devices, which are usually used by users, are utilized as main components for indoor navigation. Subsequently, it is expected that the paper can contribute to make VLC applications be more active.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.22 no.5
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• pp.560-567
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• 2011

In this paper, we reduced the optical noise interference using polarizers in a visible light communication system. In a transmitter, two light-emitting diodes(LEDs) are modulated synchronously by the original and the reversed signals of the transmitted data, and the two LED lights are radiated through orthogonal polarizers. In a receiver, two optical signals are detected through orthogonal polarizers and differentially amplified to remove the optical noise. In an environment that noise light from a fluorescent lamp is much stronger than the signal, the receiver with orthogonal polarizers removed the 120 Hz noise, and synchronous light transmission of the original and the reversed signals using two LEDs reduced the illumination flickering to about one-eighth that using one LED.

• Proceedings of the KIEE Conference
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• 1999.11d
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• pp.981-983
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• 1999

In this paper, the electrical characteristics of $\lambda$ vibration-mode piezoelectric transformer for applying to CCFL driving inverter was investigated. Piezoelectric transformer was made of PZT - PMN - 0.5wt% $Nb_{2}O_{5}$ composition. As a results of the electrical characteristics of piezoelectric transformer, when applied voltage was $35[V_{rms}]$ in $100[k{\Omega}]$ load resistance, output voltage was about $710[V_{rms}]$ and output power was more than 2[W]. As output power increased, step-up ratio and temperature was very stable until output power was 2.5[W]. Also, Efficiency was maximum in $70[k{\Omega}]$ load resistance, and about 89[%]. Also, when CCFL was used as load, the maintaining voltage was $700[V_{rms}]$ and the luminescence was $2000[cd/m^2]$ in applying $25[V_{rms}]$ to piezoelectric transformer. Conclusively, piezoelectric transformer fabricated in this paper can be applied to piezoelectric inverter for CCFL driving.