• Journal of Bio-Environment Control
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• v.27 no.2
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• pp.158-165
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• 2018

The effects of different kinds of supplementary lighting or heating lamps on the yield, cut flower life, and leaf color of cut rose were compared and analyzed. For this purpose, light emitting diode lamp (LED), metal halide lamps (MH), and high-pressure sodium lamps (HPS) as the supplementary lamps, and carbon fiber infrared lamp (NCFI) were installed on hydroponic cultivation bed in a cut rose farm. The yield of cut flower rose and the number of marketable flowers were greatly increased in spring and autumn by HPS treatment, but not in winter. The length of flower stalk was longer than that of control in the spring but decreased in winter. It seemed likely that the shorter flower stalk in winter was due to the shortened period of vegetative growth compared to the control because flowering was promoted by supplementary lighting. Vase life was not different among treatments in the autumn when the lighting time was short, but in winter, it was prolonged to 3 more days by only HPS, compared with the control. Leaf color was significantly affected by light treatment in winter rather than autumn. Leaf color was darkened in all supplementary lamps (LED, MH, HPS) treatment, whereas NCFI was similar to the control in leaf color. In conclusion, HPS is considered to be a very good supplementary lamp because it increases the length of flower stalk and the yield and prolongs vase life in cut roses. Even though NCFI could function as a heating lamp radiating a lot of heat, it was considered that the role as a supplementary light is unsatisfactory because the number of marketable flowers decreases and the quality index of cut rose deteriorates by NCFI.

• Journal of the Korean Vacuum Society
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• v.17 no.6
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• pp.481-486
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• 2008

The different degrees of blackening were observed at the inner surface of borosilicate, soda-lime, and aluminosilicate glass tubes having different sodium (Na) contents. The sodium contents ($Na_2O$) within the borosilicate, soda-lime, and aluminosilicate glass tubes were found to be 4%, 14%, and 0.06%, respectively. The degree of blackening was shown to increase as the sodium content within the glass of the fluorescent lamp containing Ne+Ar+Hg gas mixture. Higher degree of blackening was observed from the inner surface of the glass tube coated with $Y_2O_3$. The blackening was found to be originated from the amalgam of $NaHg_2$ generated by the chemical reaction between the mercury ions within the discharge gas and sodium within the glass tube during operation.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.57 no.3
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• pp.336-343
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• 2008

In this study, a transition of power quality was characterized by non-linear voltage electric equipments under voltage sag. The test was inputted voltage sag to IPC(Sag Generator) from AVR, and then to equipments by IPC which adjust voltage magnitude and duration. The load test which non-linear voltage electric equipments used PLC, Magnetic Contactor, SMPS, HID Lamp. The test result was different from each other according to a manufacturing companys, models, and equipments. PLC was greatly described to be stabilized voltage sag in case of no load then rated load. Magnetic Contactor was made a difference to phase angles on voltage sag, which was $0^{\circ}$, $30^{\circ}$, $60^{\circ}$, $90^{\circ}$. HPD Lamp was described to be stabilized the sodium lamp, and to be unstabilized the metal hailed lamp. The test result was showed CBEMA curve that stand for evaluated responsiveness of voltage sag. This study was tested description to dynamic characteristics on non-linear voltage electric equipment under voltage sag. There was hoped that power system designed the essential particulars.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2002.11a
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• pp.259-260
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• 2002

본 논문에서는 250 [W] 고압나트륨램프용 전자식 안정기를 제작하여 전기적 특성을 측정하였다. 개발한 전자식 안정기는 입력전압 220 [V]용으로, 안정된 전기적 특성을 갖는 것으로 입증되었다.

• 한국정보디스플레이학회:학술대회논문집
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• 2007.08a
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• pp.367-370
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• 2007

An EEFL with the sodium free alumino-silicate glass of high K and low $tan{\delta}$, has been investigated. As compared with borosilicate and the soda-lime EEFLs, the luminous efficiency as well as the pinhole stability of new EEFLs improves remarkably without blackening of $NaHg_2$.

• Journal of Biosystems Engineering
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• v.35 no.6
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• pp.413-419
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• 2010

Plant growth was greatly affected by the spectral distribution and light intensity of artificial lighting sources. In this study, the spectral characteristics of high power sodium (HPS) lamps and metal halide (MH) lamps produced by three different manufacturers were measured. Even though the spectral distribution of HPS lamps with lamp wattage of 250 W and 400 W was very similar, but the spectral light intensity by the manufacturers was different. Difference in the spectral light intensity of MH lamps by the manufacturers was increased with the increasing lamps wattage. Light intensity at the region of blue (B), green (G), red (R) and far-red (FR) light of HPS and MH lamps was also analyzed. HPS lamps showed the light intensity in order of R, FR, B and G light. The ratio of G, B, R and FR to photosynthetic photon flux (PPF) of HPS lamps with the lamp wattage of 250 W was 3.0-3.2%, 5.5-5.9%, 17.3-19.2% and 6.5-7.8%, respectively. For MH lamps, it showed the light intensity in order of R, FR, B, and G. The ratio of B, G, R, and FR to PPF of MH lamps with 250 W was 14.0-15.5%, 22.6-27.5%, 7.5-9.5% and 2.7-4.2%, respectively. HPS and MH lamps with 400 W had a relatively smaller ratio of R and FR to PPF than those with 250 W. HPS lamps showed that the ratio of light intensity of B and FR to R was 0.15-0.28 and 0.36-0.4, respectively. For MH lamps, the ratio of light intensity of B and FR to R was 1.26-2.72 and 0.27-0.56, respectively. From these results, it was concluded that the portion of blue light of MH lamps was higher than those of HPS lamps.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.28 no.4
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• pp.271-275
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• 2015

The floodlighting assists the pilot in taxiing the aircraft into and out of the final parking position and provide lighting suitable for passenger to embark and debark and for personnel to load and unload cargo. It is composed of sodium lamps which is consuming high energy. It needs to develop a dedicated LED lamp to replace the existing lamps. In this paper, We propose a suitable asymmetric angle of LED lamps to avoid a pilot's glare and to meet the standard illumination. For this, we analyze asymmetric angle of sodium lamps which are using in airport and confirm whether the illumination distribution and glare index meet the relating standards by using simulation method. Also, we study the needs of asymmetric characteristics of LED ramp by simulating the LED lamps with and without asymmetric characteristics of ramp respectively. With the simulation result, finally we propose the best asymmetric angle of LED lamp to meet the average illumination standard, and avoid a pilot's glare.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.16 no.2
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• pp.18-25
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• 2002

In this paper, We have researched about the Electronic Ballast for 250W HPS(High Pressure Sodium) lamp. This Electronic Ballast is capable to operate the Ignition and Steady State Using the Class D LCC resonant tank, and minimizing the full-bridge inverter's Switching Stress by implementation Quasi-square ZC-ZVS Soft Switching Method. And also, We have reduced the heat of MOS-FETs and high frequency switching surge noise using the RCD damp snubber. Therefore, We are sure that the developed ballast has the properties of the stable & reliable Control and the function of minimizing the total noise of the system.

• Journal of Environmental Science International
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• v.33 no.5
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• pp.305-322
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• 2024

The aim of this study was to investigate the effects of artificial light sources on the germination and seedling vigor of lettuce, aiming to identify the optimal artificial light source for producing high-quality seedlings. Lettuce cultivar of 'Tomalin' and 'Seonpunggold' exhibited the highest seed emergence in the Metal halide(MH) lamp and High-pressure sodium(HPS) lamp treatment group, while the emergence rate parameter, T50, was the fastest in the HPS lamp treatment group. Both cultivars showed good growth characteristics such as number of leaves, root length, and stem diameter under RGB-LED, and their seedling vigor was excellent as well. The plant height was smallest in the Red + Green + Blue LED treatment, but the leaves were round and thick, resulting in higher biomass and dry weight. Single light sources of Red LED and Blue LED led to reduced growth compared with that under the mixed light treatments. Chlorophyll content in lettuce varied with the type of artificial light, with both cultivars exhibiting the highest chlorophyll content in the Red + Green + Blue LED treatment. The most suitable artificial light for lettuce seedling growth was the Red + Green + Blue LED treatment.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 1999.11a
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• pp.114-118
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• 1999

This paper shows a structure for an electronic ballast of HID lamps. An electronic ballast for HID lamps usually employs a high-frequency resonant inverter and voltage-to-frequency converter to control the output. A half-bridge and series resonant circuit are chosen for the ballast. The inverter with V/F converter is modeled with a transfer function and a self-feedback controller is proposed. This structure is analyzed and the feedback gain is determined by using the inverter model. Experimental system is built with a commercial 250W high pressure sodium lamp and the results show a validity of the proposed ballast.