• Asian-Australasian Journal of Animal Sciences
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• v.14 no.2
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• pp.280-287
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• 2001

These studies aimed to determine how lighting might be used to improve feed intake and reduce aggressive behavior in newly weaned pigs. To examine whether this objective could be achieved an experiment was conducted to compare performance, behavior and body condition of weaners over 17-45 days, provided similar lighting quality (i.e. color temperature, color rendering index and lighting distribution) after weaning that piglets experienced prior to weaning. Triphosphor (TP) lighting to simulate daylight was provided during the day while at night, Pascal red (PR) lighting was provided to simulate the night-light piglets previously had received from infrared heating lamps. This treatment was compared to weaners provided conventional cool-white fluorescent light during the day only. Weaners on treatment lighting from 17-45 days of age showed no improvement in body weight or feed conversion at 24, 31, 38 and 45 days compared to the controls. There was, however, a significant improvement (p<0.05) in feed intake in the first week of weaning for weaners provided TP/PR lighting. Over the first 3 days of weaning, pigs on TP/PR lighting showed an increase (p<0.05) in the incidence of ear chewing but reduced (p<0.05) levels of nosing the abdomen of other pigs and reduced (p<0.05) occurrences of being stood on by other pigs. Females exhibited more (p<0.05) mounting and nosing behaviors and rubbing the heads of other pigs than males. On the other hand, males engaged in more (p<0.05) fighting, nipping, ear chewing and standing on other pigs compared to females. Pigs provided PR lighting on the first night of weaning engaged in higher (p<0.05) incidences of nosing and tail sucking behaviors, more (p<0.05) head thrusting, fighting and ear chewing compared to control pigs. The body condition of weaners provided the TP/PR lighting treatment was significantly poorer (p<0.05) compared to weaners on control lighting. In conclusion there was no improvement in production performance of weaners provided new technology lighting apart from the improvement in feed intake in the first week weaners were exposed to the TP/PR lighting.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.2
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• pp.666-671
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• 2016

This paper introduces a device providing close local lighting to the affected part, where the operation-purpose astral lamp alone cannot shed light directly, in an operation room of hospitals or clinics, which helps clinical doctors perform safe treatment of the affected part deep inside a human body. This medical assisting lighting is a device necessary to prevent fatal operation failures, which can occur with minute operation processes, such as tumor removal or angiorrhaphy. The components, such as the light source and power supply were designed to be low power consuming and small in size, have a narrow angle lens was used to increase the light spreading effect and focused illumination. The end-caps of the light transmission device using an optical cable and the lighting device were designed in the waterproof type to enable disinfection of these devices after use for the next patients. According to the measurement of the light source properties made after development of the retractor lighting device, the illumination intensity was 490 lux, the brightness was $11,550cd/m^2$, general color rendering index was 78, color temperature was 11,000K, and the intensity distribution was even, which were confirmed to be adequate for medical assisting local lighting.

• Journal of Surface Science and Engineering
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• v.47 no.4
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• pp.192-197
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• 2014

Red-emitting nitride phosphors recently attracted considerable attention because of their high thermal stability and high color rendering index properties. For excellent phosphor of white light-emitting-diode, ternary nitride phosphor of $Sr/SmSi_5N_8:Eu^{2+}$ with different $Eu^{2+}$ ion concentration were synthesized by solid state reaction method. In this work, red-emitting nitride $Sr/SmSi_5N_8:Eu^{2+}$ phosphor was successfully synthesized by using multi-step high frequency induction heat treatment. The effects of molar ratio of component and experimental conditions on luminescence property of prepared phosphors have been investigated. The structure and luminescence properties of prepared $Sr/SmSi_5N_8:Eu^{2+}$ phosphors were investigated by XRD and photoluminescence spectroscopy. The excitation spectra of $Sr/SmSi_5N_8:Eu^{2+}$ phosphors indicated broad excitation wavelength range of 300 - 550 nm, namely from UV to visible area with distinct enhanced emission peaks. With an increase of $Eu^{2+}$ ion concentration, the peak position of emission in spectra was red-shifted from 613 to 671 nm. After via multi-step heat treatment, prepared phosphor showed excellent luminescence properties, such as high emission intensity and low thermal quenching, better than commercial phosphor of $Y_3Al_5O_{12}:Ce^{3+}$. Using $Eu_2O_3$ as a raw material for $Eu^{2+}$ dopant with nitrogen gas flowing instead of using commercial EuN chemical for $Sr/SmSi_5N_8:Eu^{2+}$ synthesis is one of characteristic of this work.

• Journal of the Korea Safety Management & Science
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• v.12 no.4
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• pp.41-51
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• 2010

This paper describes the development of various lighting equipment adapting Ultra Constant Discharge Lamp that has newly been on commercial supply in the market. Meeting the required conditions of lighting equipment, various types of UCD Lamp equipment with excellent performances could be successfully developed. In order to provide a guideline for the economical lighting product selection, the analyzed data comparison between Hi-pressure Sodium Lamp which has been the most popular lamp for street lighting and UCD Lamp is provided. The conclusions of the study are made as follows; (1) The performance measurement result of UCD Lamp shows excellent Luminous Efficacy as 108Lm/W, daylight-like Color Rendering Index as 90Ra, and the best operating temperature range as $-50^{\circ}C{\sim}+85^{\circ}C$. Comparing to the Hi-pressure Sodium Lamp, UCD could be evaluated as much superior products. (2) In an assembled status with the lighting fixture (Type STB형-60W), UCD Lamp was tested OK for one hour duration at the temperature range form $-50^{\circ}C$ to $+85^{\circ}C$ and the humidity of 98%. The operation at the extremely low temperature can be an excellent feature to enable the export to the cold temperature regions such as Northern Europe and Russia and the specific applications for defense systems and special industry. (3) As UCD Lamp is a genuine Korea made product following Energy-saving and Eco-friendly policy, it should be appreciated as one of the best $CO^2$ reduction Green product.

• Korean Journal of Optics and Photonics
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• v.24 no.2
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• pp.64-70
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• 2013

In this paper, two white light emitting diodes(LEDs) were manufactured by using two kinds of yellow phosphor, YAG:Ce and $(Sr,Ba)_2SiO_4:Eu$, and their spectroscopic properties were compared and analyzed. We found that the asymmetric double sigmoidal function can be applied to both white LEDs to obtain the center wavelength, the half width, and the skewness parameters. According to this analysis, the half width of the emitting spectrum of silicate phosphor was smaller than that of YAG phosphor, indicating smaller color rendering index. However, the silicate phosphor exhibited better color stability depending on the driving current than the YAG phosphor. The current dependence of the luminous efficacy of both white LEDs was investigated, which showed that efficacy decreased monotonically with current. The efficacy of the silicate-based white LED was lower than that of the YAG-based LED by about 10~12 lm/W.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.22 no.12
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• pp.1-9
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• 2008

This paper is about l00[W] discrete LED floodlight lighting system, light color and color temperature to be controlled using the 3[W] RGBA LED, is developed the product with optical, heat dissipation, circuit, luminaire and system design. The result, color temperature is changed corresponding to black body locus from 2,000[K] to 10,000[K] and The Color Rendering Index(C.R.I) is achieved from 71 to 91 by high C.RI. Driving voltage is $90{\sim}250[Vac]$, circuit efficiency is 87[%], P.F is more than 93. moreover the LED lens is designed to achieve narrow, middle, wide beam angle, heat dissipation design is executed to minimize variation of luminous output by the surroundings temperature and to ensure reliability.

• Journal of Surface Science and Engineering
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• v.48 no.5
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• pp.211-217
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• 2015

To fabricate white LED having a high color rendering index value, red color phosphor mixed with the green color phosphor together in the blue chip, namely the blue chips with RG phosphors packaging is most favorable for high power white LEDs. In our previous papers, we reported on successful syntheses of $Sr_{2-}$ $Si_5N_8:Eu^{2+}$ and $CaAlSiN_3$ phosphors for red phosphor. In this work, for high power green phosphor, greenemitting ternary nitride $Ba_3Si_6O_{12}N_2:Eu^{2+}$ phosphor was synthesized in a high frequency induction furnace under $N_2$ gas atmosphere at temperatures up to $1400^{\circ}C$ using $EuF_3$ as a raw material for $Eu^{2+}$ dopant. The effects of molar ratio of component and experimental conditions on luminescence property of prepared phosphors have been investigated. The structure and luminescence properties of prepared $Ba_3Si_6O_{12}N_2:Eu^{2+}$ phosphors were investigated by XRD and photoluminescence spectroscopy. The excitation spectra of $Ba_3Si_6O_{12}N_2:Eu^{2+}$ phosphors indicated broad excitation wavelength range of 250 - 500 nm, namely from UV to blue region with distinct enhanced emission spectrum peaking at ${\approx}530nm$.

• Journal of the Institute of Convergence Signal Processing
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• v.19 no.4
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• pp.167-173
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• 2018

We propose an air purification system that utilizes aerial plant parts and root zone of indoor plants where light is insufficient and air circulation is bad. In order to maximize the air purification effect of the plant, the aerial plant parts illuminates mixed light combining blue and green LED and CRI(Color Rendering Index) LEDs close to natural light, respectively. And the root zone was forcibly circulated by the fan to use the soil as a filter. The indoor air purification system combined with the light source and the fan removed most polluted air in the shortest. In the case of mixed light and CRI LEDs of indoor air purification system, fine dust decreased by 14%, 14.2%, and TVOC(Total volatile organic compounds) decreased by 7.5% and 9.4%, respectively. In the experiment in which the fan was operated for 15 minutes, the TVOC decreased to 97.8%. The photosynthesis of the plant and the use of soil as a filter were able to purify polluted air in a short time. And the fan's temporary operation gave the similar effect of continuous operation.

• Journal of The Korea Institute of Healthcare Architecture
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• v.24 no.4
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• pp.69-87
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• 2018

Purpose: This study has been started with the awareness that light and color are the main visual sensors of the multi-sensory stimulation environment to achieve the therapeutic environment for demented elderly. The purpose of this study therefore is for clarifying the application characteristics of therapeutic light and color for dementia care facilities. Methods: Internal and external literature reviews have been conducted for the investigation into a)disorders and visual system in demented elderly, b)therapeutic effects of light and color, c)heliotherapy, light therapy and color therapy to deduce the therapeutic characteristics of light and color for demented elderly, and finally into d)the application characteristics of it for dementia care facilities. Results: The application characteristics of the therapeutic light and color for dementia care facilities are classified into both qualitative and quantitative characteristics. Qualitative application characteristics of light represented using of daylight, using of lighting approximate to daylight, expansion of iluminance level, equality in iluminance Level, reduction of shadow, and as well as exclusion of blare. Quantitative application characteristics of it represented iluminance level, color temperature and color rendering index prescribed in international lighting standards. Qualitative application characteristics of color represented non-monochromatic color, color contrast, long wavelength of yellow-red colors, exclusion of short wavelength of blue colors and patterns, and as well as different colors for idenfication. Quantitative application characteristics of it represented kontrast(K) prescribed in DIN32975:2009 and light reflectance value(LRV) prescribed in BS8300:2009. Implications: To form dementia care facilities as therapeutic environment both qualitative and quantitative application characteristics of therapeutic light and color in dementia care facilities are needed.

• Korean Journal of Materials Research
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• v.29 no.2
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• pp.116-120
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• 2019

We prepared $Y_3Al_5O_{12};Ce^{3+},Pr3^{+}$ transparent ceramic phosphor using a solid state reaction method. By XRD pattern analysis and SEM measurement, our phosphors reveal an Ia-3d(230) space group of cubic structure, and the transparent ceramic phosphor has a polycrystal state with some internal cracks and pores. In the Raman scattering measurement with an increasing temperature, lattice vibrations of the transparent ceramic phosphor decrease due to its more perfect crystal structure and symmetry. Thus, low phonon generation is possible at high temperature. Optical properties of the transparent ceramic phosphor have broader excitation spectra due to a large internal reflection. There is a wide emission band from the green to yellow region, and the red color emission between 610 nm and 640 nm is also observed. The red-yellow phosphor optical characteristics enable a high Color Rendering Index (CRI) in combination with blue emitting LED or LD. Due to its good thermal properties of low phonon generation at high temperature and a wide emission range for high CRI characteristics, the transparent ceramic phosphor is shown to be a good candidate for high power solid state white lighting.