• FLOWER RESEARCH JOURNAL
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• v.26 no.4
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• pp.166-178
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• 2018

In this study, the principal objective was to investigate the effect of light quality and vessel ventilation on the growth and development, physiology, activities of antioxidant enzymes, and contents of mineral nutrients of carnation (Dianthus caryophyllus L.) 'Marble Beauty'. Single node cuttings stuck into the plant growth regulator (PGR)-free MS medium in containers covered with caps with or without a ventilation filter were cultured first four weeks under white and then additional four weeks under either white (control), blue, red, or red + blue light emitting diodes (LEDs) for 56 days. Interestingly, a ventilated culture condition not only reduced the percentage of the hyperhydricity, but also increased the total chlorophyll content (Chl a + Chl b) of the plantlets as compared to the non-ventilated condition. In addition, blue LEDs produced plantlets with the greatest number of shoots and red LEDs produced plantlets with the greatest shoot length. The quality of plantlets was improved under a ventilation condition. Besides, under a ventilated condition, red + blue LEDs raised APX activity, and blue LEDs not only raised the activity of the CAT, but also increased tissue contents of such elements as K, Ca, Mg, Zn, Mn and Fe. The red LEDs increased contents of B and Si under a ventilated condition, and Na accumulation under a non-ventilated condition. Thus, including blue or red LEDs as the light source in a ventilated culture condition will produce plantlets of carnation 'Marble Beauty' in vitro with improved quality.

• Korean Journal of Agricultural Science
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• v.10 no.2
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• pp.242-248
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• 1983

The effects of light source, plant growth regulators (GA, BA, ABA), and sodium hypochlorite (4% Cl, SH) on germination of 'G rand Rapid' lettuce (Lactuca sativa L.) seed were studied. Seed did not germinate under the conditions of dark and blue light. The treatment of GA or BA did not promote on germination under dark or blue light. The germination percentage under red light was very high, it was similar to the condition of white light. ABA inhibited lettuce seed germination. Although ABA was treated, BA 10ppm treatment was moderately effective under white light condition and BA 10ppm or 50ppm combined with GA 50ppm were also effective on seed germination under dark condition. Presoaking in sodium hypochlorite solution induced germination of lettuce seed in any condition of dark or white light. The optimum presoaking time in sodium hypochlorite solution was twenty min.

• Journal of the Korean Society of Systems Engineering
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• v.18 no.1
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• pp.1-13
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• 2022

The Yongin Light Rail train was manufactured by Bombardier Transportation in Canada in 2008 and is a privately invested railway line that has been operating in Yongin-si, Gyeonggi-do, since 2013. When the frequency of train failure increases due to aging, and there is a delay in the delivery period of imported parts used in the Bombardier manufactured trains, timely vehicle maintenance may not be performed due to lack of parts. To solve this problem, it is necessary to build a 'vehicle parts maintenance demand forecasting system' that analyzes the accurate and actual maintenance demand annual based on the condition of vehicle parts. The full scope of analysis in this paper analyzes failure data from various angles after opening of Yongin light rail vehicle to analyze failure patterns for each part and identify replacement cycles according to possible failures and consumption of parts. Based on this study, it is expected that Yongin Light Rail's maintenance system will change from the existing time-based replacement (TBM) concept to the condition-based maintenance (CBM) concept. It is expected that this study will improve the efficiency of the Yongin Light Rail maintenance system and increase vehicle availability. This paper is a fundamental for establishing of a system for predicting the replacement timing of vehicle parts for Yongin Light Rail. It reports the results of data analysis on some vehicle parts.

• Asian Journal of Turfgrass Science
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• v.9 no.3
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• pp.253-260
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• 1995

This study is aimed to understand the effects of temperature, light and GA soaking treatment on the seed germination of perennial ryegrass 'Dandy', creeping hentgrass 'Penlinks', tall fescue 'Arid' and Kentucky hluegrass 'Nasaw'. These experiments are carried in vitro, and their results obtained are summarized as the followings ; The optimum temperature for seed germination of perennial ryegrass 'Dandy' was found to he ranged at 20~30$^{\circ}C$, and the optimum temperature for germination of creeping bentgrass 'Penlinks', tall fescue 'Arid' and kentucky bluegrass 'Nasaw' seeds was found to be ranged at 20~25$^{\circ}C$, whereas the germination percentage under the below or above temperature of this range decreased. The germination of perennial ryegrass 'Dandy' and tall fescue 'Arid' seeds showed no effect on light, and while the germination percentage of creeping hentgrass 'Penlinks' increased more highly under the dark condition than under the light condition. The germination percentage decreased according to the higher temperature. The germination of Kentucky bluegrass 'Nasaw' seeds increased more highly under the dark condition than under the light condition at 20~25$^{\circ}C$, whereas the germination percentage under the dark condition at 15$^{\circ}C$ and 30$^{\circ}C$ decreased. In case of GA soaking treatment of seeds, all the cool season turfgrasses tested showed their own promoting effects on seed germination. The early germination of tall fescue 'Arid' was good without the soaking times. Creeping bentgrass 'Penlinks' and perennial ryegrass 'Dandy' had re-spectively the highest germination percentage at 10min and 1hr soaking treatment, and the longer the soaking time, the lesser the germination percentage. Kentucky bluegrass 'Nasaw' obtained the best results at 24has soaking treatment, and the longer the soaking time, the better the ger-mination percentage.

• Korean Journal of Plant Tissue Culture
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• v.22 no.2
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• pp.71-76
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• 1995

The effects of light on the activities of several antioxidative enzymes, catalase (CAT), superoxide dismutase(SOD), ascorbate oxidase(AO), and peroxidase(POD) were examined in the hairy root cultures of Phytolacca esculenta van Houtte induced by Agrobacterium tumefaciens $A_4$T. Activities of CAT, SOD, and AO were significantly decreased with incresing light intensity (500-2,000 lx). The activity of AO under high light condition (2,000 lx)was decreased by 92% compared to the dark condition. The activities of glutathoine peroxidase (GPO), ascorbate peroxidase (APO) and general POD were increased under lower light intensify below 500 lx. The activity of GPO under 2,000 lx was decreased by 85% compared to the dark condition. The activities of antioxidative enzymes were more decreased in blue light (400-500nm). The activities of antioxidative enzymes in blue light intensity were increased in lower light intensity below 30 lx, but decreased 21-70% under 200 lx. The activity of AO was decreased by 70% under 200 lx with increasing blue light intensity. Our results suggest that the activities of antioxidative enzymes in hairy roots might be inhibited by endogenous oxidants generated under the high blue light conditions.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1998.11a
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• pp.61-64
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• 1998

We have investigated the effects of ultraviolet (UV) light irradiation condition and imidization temperature for the generation of pretilt angle in nematic liquid crystal (NLC) on the two kinds of the polyimide (PI) surfaces. High pretilt angle of NLC is generated with oblique p-polarized UV light irradiation of 30$^{\circ}$ on PI surface for 20 min. Also, the high pretilt angle of NLC is generated with oblique p-polarized UV light irradiation of 10-30$^{\circ}$ on PI surface at 20min. The pretilt angle of NLC decreases with increasing the imidization temperature on all rubbed PI surfaces ; the pretilt angle of NLC with oblique p-polarized UV light irradiation of 30$^{\circ}$on PI surface decreases with increasing the imidization temperature. The high pretilt angle of NLC is observed due to high photo-depolymerization reaction by low surface energy at low imidization temperature. We suggest that the pretilt angle of NLC is strongly attributed to the photo-depolymerization reaction with the UV light irradiation condition and imidization temperature.

• Journal of the Korea Institute of Military Science and Technology
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• v.5 no.2
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• pp.149-158
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• 2002

Static Characteristics of the system, such as weight, center of gravity etc., are inspected and regulated through the whole design process of a light weight torpedo system, and the nominal condition of the characteristics is prescribed for standardization of manufacturing and fabrication. It is possible that a real system or assembled system has different static characteristics from that of the nominal condition. It is required to evaluate the tolerance of the static characteristics within which the performance of the system should not be contaminated by the static characteristics. In this paper, an evaluation method of the tolerance is described for light weight torpedo systems. The method is to check on the performance and related critical parameters of light weight torpedoes. The checking items are composed of general conditions of underwater mobile systems such as stability and dynamic sensitivity and specified performance requirements for light weight torpedoes.

• Journal of Animal Reproduction and Biotechnology
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• v.35 no.2
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• pp.171-176
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• 2020

Advancing the estrous cycle of mares is an essential breeding strategy that is routinely conducted by Thoroughbred breeders to improve economic outcomes. For this purpose, Equilume light masks have been developed as an alternative to existing technologies such as artificial lighting or hormonal treatments because they are considered as valid as existing methods with additional animal welfare advantages. For example, with the Equilume light masks, horses can be let out into the pasture, whereas they have to be kept indoors during lighting treatment. Because the function of Equilume light mask on the estrous cycle of mares is influenced by environmental factors such as nutrition condition and temperature, Equilume light mask should be studied in various environments. The objective of the present study was thus to verify the effect of Equilume light masks on the onset of the estrous cycle in Thoroughbred mares in South Korea. Mares were randomly selected and separated into two groups at two Thoroughbred horse breeding farms. The mares in the treatment group were equipped with Equilume light masks from November 18 to February 10 the following year. The body condition, the number and size (> 35 mm) of uterine follicles, and the uterine horn score of the mares were assessed on January 6 and February 10. The body condition scores were not different between the two groups. The treatment with the Equilume light mask had no positive effects on developing follicles and the reproductive tract. In conclusion, the use of Equilume light masks did not influence the seasonal resumption of the estrus cycles in Thoroughbred mares in South Korea.

• Journal of the Korean Institute of Landscape Architecture
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• v.27 no.5
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• pp.114-119
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• 2000

This study was carried out to obtain fundamental information of growth response of ground cover plants under artificial light quality at indoor. Aglaonema 'Silver Queen', Hedera helix L., Hoya carnosa 'Tricolor' and Saintpaulia ionantha 'Frances' were examined under a 400lux light intensity consisted of Mercury lamp, True-lite lamp, incandescent lamp, dark-room and sunlight indoor condition. A data analysis were performed by GLM, Duncan's multiple range test and mean score with SAS program. Results of experiments are as follows; 1. A plant growth status was better showed under the True-lite lamp than sunlight. 2. A Saintpaulia ionantha flower color was responded in the first place, the deep pinkish red color of Saintpaulia ionantha flower was obtained under Mercury lamp and "True-lite lamp", "sunlight", and incandescent lamp were follow. Flower numbers of Saintpaulia ionantha after 60 days tended to decrease under every artificial light quality. 3. Leaf length and leaf width were increased under True-lite lamp, but most of plants was not significantly affected by artificial light quality. 4. A stem length of Hedera helix was increased the highest rank under sunlight also, one of artificial light, the highest increase rank was showed under incandescent lamp. 5. Chlorophyll content was highly increased under Mercury lamp, but was responded poor under incandescent lamp.

• Sleep Medicine and Psychophysiology
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• v.28 no.1
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• pp.27-33
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• 2021

Objectives: The purpose of this study is to investigate the difference in the effects of eye-mask and light-off on sleep status according to a commercial fitness tracker and a sleep diary of psychiatric in-patients in correctional facilities where nocturnal light is compulsory. Methods: This study was conducted over 3 consecutive nights. In-patients of the National Forensic Psychiatric Hospital (n = 29) were assigned random subject numbers and slept as usual in the light-on condition on the first night. The subjects slept with eye-masks in the light-on condition on another night and without an eye-mask in the light-off condition on the other night. Subjects were asked to sleep wearing a commercial fitness tracker and to keep a sleep diary. The order of these changes in bedroom lighting condition on the second and third nights was assigned randomly to participants. Results: In comparison of the sleep variables between the light-on condition and the eye-mask condition, the Wakefullness After Sleep Onset (WASO) was shorter and sleep satisfaction was higher in the latter.(respectively, Z = 3.66, p < 0.017 ; Z = 2.69, p < 0.017) In comparison of the sleep variables between the light-on and light-off conditions, the WASO was shorter and sleep efficiency and sleep satisfaction were higher in the latter (respectively, Z = 2.40, p < 0.017 ; Z = 3.02, p < 0.017 ; Z = 3.88, p < 0.017). However, there were no differences in the sleep variables between the eye-mask condition and the light-off condition. Conclusion: Subjective improvements in sleep variables were noted in sleep diaries of institutionalized psychiatric patients under either the 'eye-mask' or 'light-off' condition. However, there were no significant differences between the 'eye-mask' and 'light-off' conditions. Therefore, we suggest that psychiatric patients in correctional facilities use eye-masks when sleeping.