• Proceedings of the International Microelectronics And Packaging Society Conference
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• 2001.04a
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• pp.57-65
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• 2001

Economical consumption of energy, longer life of lamps, higher lighting comfort and new aesthetic of illumination is subject of numerous research and development works. The halogen lamps are an example of positive solution some of above mentioned problems. The electronic transformers are more frequent used for their supply. In comparison with conventional transformers they have less weight, less volume and 60% less power tosses. Their advantages are particular visible, when the hybrid technique is applied. The paper presents the results of engineering research and development works carried out ill Private Institute of Electronic Engineering, in R. & D. Center for Hybrid Microelectronics and Resistors and in Technical School of Communications in Krakow, in the field of the design and exploitation tests of hybrid converters 220V AC /12V DC (electronic transformers) and electronic ballasts destined for the supply of halogen lamps 20W to 150W and fluorescent lamps respectively. To perform the converters, thick film technology and surface mount technology were used. For the protection of converter electronic circuit the thick film temperature sensor and transistors were applied. Moreover the paper presents the base application circuits of elaborated converters, their technical parameters and exploitation results. The development perspectives of hybrid domain of hybrid circuits are also discussed.

• Journal of the Optical Society of Korea
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• v.20 no.4
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• pp.488-499
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• 2016

We present a design and optical simulation of a cost-effective hybrid daylighting/LED system composed of mixing sunlight and light-emitting diode (LED) illumination powered by renewable solar energy for indoor lighting. In this approach, the sunlight collected by the concentrator is split into visible and non-visible rays by a beam splitter. The proposed sunlight collector consists of a Fresnel lens array. The non-visible rays are absorbed by the solar photovoltaic devices to provide electrical power for the LEDs. The visible rays passing through the beam splitters are coupled to a stepped thickness waveguide (STW) by tilted mirrors and confined by total internal reflection (TIR). LEDs are integrated at the end of the STW to improve the lighting quality. LEDs’ light and sunlight are mixed in the waveguide and they are coupled into an optical fiber bundle for indoor illumination. An optical sensor and lighting control system are used to control the LED light flow to ensure that the total output flux for indoor lighting is a fixed value when the sunlight is inadequate. The daylighting capacity was modeled and simulated with a commercial ray tracing software (Lighttools^TM). Results show that the system can achieve 63.8% optical efficiency at geometrical concentration ratio of 630. A required accuracy of sun tracking system achieved more than ±0.5^o . Therefore, our results provide an important breakthrough for the commercialization of large scale optical fiber daylighting systems that are faced with challenges related to high costs.

• Journal of the Optical Society of Korea
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• v.18 no.5
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• pp.507-516
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• 2014

We present a hybrid method for spectral reflectivity recovery, using 3D extrapolation as a supplemental method for 3D interpolation. The proposed 3D extrapolation is an extended version of 3D interpolation based on the barycentric algorithm. It is faster and more accurate than the conventional spectral-recovery techniques of principal-component analysis and nonnegative matrix transformation. Four different extrapolation techniques (based on nearest neighbors, circumcenters, in-centers, and centroids) are formulated and applied to recover spectral reflectivity. Under the standard conditions of a D65 illuminant and 1964 $10^{\circ}$ observer, all reflectivity data from 1269 Munsell color chips are successfully reconstructed. The superiority of the proposed method is demonstrated using statistical data to compare coefficients of correlation and determination. The proposed hybrid method can be applied for fast and accurate spectral reflectivity recovery in image processing.

• Journal of the Microelectronics and Packaging Society
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• v.8 no.2
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• pp.43-48
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• 2001

Economical consumption of energy, longer life of lamps, higher lighting comfort and new aesthetic of illumination is subject of numerous research and development works. The halogen lamps are an example of positive solution some of above mentioned problems. The electronic transformers are more frequent used for their supply. In comparison with conventional transformers they have less weight, less volume and 60% less power losses. Their advantages are particular visible, when the hybrid technique is applied. The paper presents the results of engineering research and development works carried out in Private Institute of Electronic Engineering, in R. & D. Center for Hybrid Microelectronics and Resistors and in Technical School of Communications in Krakow, in the field of the design and exploitation tests of hybrid converters 220V AC /12V DC (electronic transformers) and electronic ballasts destined for the supply of halogen lamps 20W to 150W and fluorescent lamps respectively. To perform the converters, thick film technology and surface mount technology were used. For the protection of converter electronic circuit the thick film temperature sensor and transistors were applied. Moreover the paper presents the base application circuits of elaborated converters, their technical parameters and exploitation results. The development perspectives of such domain of hybrid circuits are also discussed.

• Journal of IKEEE
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• v.23 no.3
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• pp.826-831
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• 2019

The stand-alone photovoltaic power systems are widely used for lighting equipment and CCTV. In order for these devices to be competitive, the life of power storage devices such as batteries is very important. The characteristic Hybrid supercapacitor is the high power density and long life. We have proposed a stand-alone photovoltaic power system that uses hybrid supercapacitor. The charge and discharge characteristics and the internal resistance of the hybrid capacitor were measured to configure the power converter. A stable maximum output point tracking control algorithm is proposed even with the change in solar radiation. In order to verify the validity of the proposed system, a prototype was fabricated and tested using a 18W hybrid capacitor and a 10W solar cell.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.29 no.11
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• pp.6-17
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• 2015

In this paper, colors of broadcast lightings composed of Red, Green, and Blue LED(Light Emitted Diode) can be linearly and quantitatively controlled in low illuminance. Because LED cannot emit uniform illuminance in low illuminance, the colors of RGB LED are unmixable. Furthermore, the illuminances are nonlinear with the dimming values of the RGB LED due to the nonlinearity of the output illuminance with the current through the LED. This nonlinearity generated errors of the target colors and illuminances. The proposed algorithm set up the target colors, which is expressed by the color coordinates in CIE 1931 color space, and the target illuminances. Then the illuminances of RGB LED were calculated using color mixing theory. The calculated illuminances determined the dimming values of the RGB LED for transmission via DMX512 communication. After the broadcasting lighting received the dimming values of the RGB LED via DMX512 communication,.RGB LED can emit target color and illuminance, and be controlled by calculating the PWM(Pulse Width Modulation) duty ratio of the hybrid LED driver which be considered the nonlinearity for the illuminances of the LED. As a result, the proposed algorithm can linearly and quantitatively control the colors and illuminances in full range of illuminance. Then we verify experimentally that the errors of the emitted color coordination x, y and illuminance are 2.27%, 3.6% and 1.5%, respectively.

• Fisheries and Aquatic Sciences
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• v.26 no.8
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• pp.500-513
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• 2023

The effects of prolonged photoperiod (additional night lighting) were investigated on the production of Ocimum basilicum (lemon basil) and fish/crayfish raised in a nutrient film technique aquaponic system. Hybrid lemon fin barb and red claw crayfish juveniles were co-cultured with O. basilicum and subjected to 12 h of ambient natural daylight and additional 0, 4, 8, and 12 h of night lighting for 14 weeks (two batches of 7 weeks each). The water quality parameters and the performance characteristics of the fish/crayfish/plant were evaluated, and the nutri- ent uptake (nitrogen, phosphorus, and potassium) in the system by the three organisms was also measured. The fish growth performance showed no significant differences (p > 0.05) in all the growth parameters measured across the treatments. The body proximate and nitrogen, phosphate, and potassium (NPK) composition of the fish and crayfish were not significantly (p > 0.05) different across the treatments. Similarly, there was no significant difference (p > 0.05) in the NPK uptake by the fish and crayfish across the treatments. The plant growth performance showed that there were no significant (p > 0.05) differences in the plant growth parameters measured, except for % plant height gained in the 12 h-light treatment (403.2 ± 26.0%) which was significantly (p < 0.05) higher than other treatments and cycles. Hence, this study demonstrat- ed that varying supplementary night lighting has no significant effect on the growth performance of O. basilicum, hybrid lemon fin barb, and red claw crayfish. This study, therefore, suggests that supplementary night lighting should not be considered for O. basilicum production as it does not significantly improve the performance characteristics of the plant nor the fish co-cultured with it in a polyculture aquaponic system.

• Horticultural Science & Technology
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• v.35 no.1
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• pp.21-29
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• 2017

This study was conducted to determine the effects of artificial lighting sources on vegetative growth of Phalaenopsis and Doritaenopsis (an intergeneric hybrid of Doritis and Phalaenopsis) orchids. One - month - old plants were cultivated under fluorescent lamps, cool - white light - emitting diodes (LEDs), or warm - white LEDs at 80 and $160{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$. The blue (400 - 500 nm) : green (500 - 600 nm) : red (600 - 700 nm) : far - red (700 - 800 nm) ratios of the fluorescent lamps, cool-white LEDs, and warm-white LEDs were 1 : 1.3 : 0.8 : 0.1, 1 : 1.3 : 0.6 : 0.1, and 1 : 2.7 : 2.3 : 0.4, respectively. Each light treatment was maintained for 16 weeks in a closed plant-production system maintained at $28^{\circ}C$ with a 12 h photoperiod. The longest leaf span, as well as the leaf length and width of the uppermost mature leaf, were observed in plants treated with warm-white LEDs. Plants grown under fluorescent lamps had longer and wider leaves with a greater leaf span than plants grown under cool-white LEDs, while the maximum quantum efficiency of photosystem II was higher under cool-white LEDs. The vegetative responses affected by different lighting sources were similar at both 80 and $160{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$. Leaf span and root biomass were increased by the higher light intensity in both cultivars, while the relative chlorophyll content was decreased. These results indicate that relatively high intensity light can promote vegetative growth of young Phalaenopsis plants, and that warm - white LEDs, which contain a high red-light ratio, are a better lighting source for the growth of these plants than the cool-white LEDs or fluorescent lamps. These results could therefore be useful in the selection of artificial lighting to maximize vegetative growth of Phalaenopsis plants in a closed plant - production system.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.30 no.1
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• pp.48-53
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• 2017

We report the studies on the red organic phosphor by using perylene bisimide derivatives. Even though perylene bisimide derivatives have excellent thermal stability and luminous efficiency, they have low solubility in organic solvents. In this research, modified perylene bisimide derivative, N,N'-Bis(4-bromo-2, 6-diisopropylphenyl)-1, 6, 7, 12-tetraphenoxyperylene-3, 4, 9, 10-tetracarboxyl bisimide (1C), has been prepared by the reaction of phenol with N,N'-Bis(4-bromo-2, 6-diisopropylphenyl)-1, 6, 7, 12-tetrachloroperylene-3, 4, 9, 10-tetracarboxyl bisimide (1B) in presence of DMF, at $70^{\circ}C$. The synthesized (1C) was characterized by using $^1H-NMR$, FT-IR, UV/V is spectroscopy, and TGA. The absorbtion and emission of (1C) was shown at 576 nm and 610 nm in UV/V is spectrum. In TGA thermogram, (1C) showed good thermal stability without significant weight loss to $220^{\circ}C$. And in the solubility analysis, (1C) with phenoxy group showed the good solubility in general organic solvents. The blended films of (1C) with PMMA (polymethyl methacrylate) at different weight % concentration such as 10, 5, 1 weight % have been prepared. The blended film was shown at 616 nm when monitored at 450 nm in PL emission spectra.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.33 no.3
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• pp.194-200
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• 2020

Perylene bisimide derivatives are developed for red organic phosphor because of their advantages, such as excellent luminous efficiency and high thermal stability. Despite these advantages, they have poor solubility characteristics in organic solvents and short emission wavelength as red organic phosphor for hybrid light-emitting diodes (LEDs). In this study, we prepared terrylene bisimide using a coupling reaction and swallow-tail imide group, which has excellent solubility. The structures and properties of swallow-tail terrylene bisimide (9C) were analyzed using ¹H-nuclear magnetic resonance (¹H-NMR), Fourier-transform infrared (FT-IR), UV/Vis spectroscopy, and thermal gravimetric analysis (TGA). The maximum absorption wavelength of (9C) in the UV/Vis spectrum was 647 nm, and the maximum emission wavelength was 676 nm. In the TGA, (9C) demonstrated good thermal stability with less than 5 wt% weight loss up to 415℃. In the solubility test, (9C) has a good solubility of more than 5 wt% in chloroform and dichloromethane. When the compounds (9C) were mixed with PMMA (polymethly methacrylate), the films showed peaks at 680 nm in the PL spectra. The results verify the suitability of (9C) as a red organic phosphor for hybrid LEDs.