• Journal of IKEEE
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• v.25 no.2
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• pp.267-272
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• 2021

Recently, attention has been focused on renewable energy and carbon neutrality to resolve fossil energy depletion and environmental problems. In addition, high-rise urban buildings and an increase in building energy are rapidly increasing. There are many restrictions on installing solar power in urban areas. In addition, as buildings become taller, a lot of low-light environments in which shade is formed occur. Therefore, in this study, we intend to develop a power plant capable of generating electric power in an outdoor low-light environment and indoor lighting environment. The power plant in a low-light environment used a dye-sensitized solar cell. A unit cell and a 20cm×20cm module were manufactured, and the electrical characteristics of the power plant were measured using light sources of LED, halogen lamp, and 3-wavelength lamp. The photoelectric conversion efficiency of the unit cell was 17.2%, 1.28%, 19,2% for each LED, halogen lamp, and 3-wavelength lamp, and the photoelectric conversion efficiency of the 20cm×20cm module was 10.9%, 8.7%, and 11.8%, respectively. In addition, the maximum power value of the module was 13.1mW, 15.7 mW, and 14.2 mW for each light source, respectively, confirming the possibility of power generation in a low-light environment

• Journal of Korean Ophthalmic Optics Society
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• v.19 no.2
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• pp.253-260
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• 2014

Purpose: The present study was conducted to investigate whether near work with smartphone could induce the change of accommodative function. Methods: Total 63 subjects(26 male and 37 female) in their 20s were firstly examined their visual functions related to accommodation and uncorrected spherical equivalent power as the control. After that, the subjects were asked to read a book for 30 min and sequentially watch a movie on smartphone for the same time after 30 min-break under the indoor light or as it was in the reverse order to avoid time-ordered effect. Their accommodative functions, 1) accommodative amplitude, 2) accommodative facility, 3) relative positive/negative accommodation, and 4) accommodative lag and their uncorrected spherical equivalent power were examined again following each task and compared with the control values. Results: The monocular accommodative amplitude was significantly decreased after smartphone watching compared with it after reading. The monocular and binocular accommodative facilities were tended to reduce after smartphone watching and book reading but were not significantly different. Neither significant change in positive relative accommodation was determined after smartphone watching nor book reading. Negative relative accommodation after smartphone watching was almost unchanged unlike reading a book. The accommodative lag after smartphone work was significantly higher than after book reading. Conclusions: The near work with a smartphone for 30 min induced the change of some accommodative functions, which was significantly greater than when reading under the same working environment.

• Radiation Oncology Journal
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• v.9 no.1
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• pp.123-130
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• 1991

A docking intraoperative electron beam applicator system, which is easily docking in the collimator for a linear accelerator after setting a sterilized transparent cone on the tumor bearing area in the operation room, has been designed to optimize dose distribution and to improve the efficiency of radiation treatment method with linear accelerator. This applicator system consisted of collimator holder with shielded metals and docking cone with transparent acrylic cylinder, A number of technical innovations have been used in the design of this system, this dooking cone gives a improving latral dose coverage at therapeutic volume. The position of $90\%$ isodose curve under suface of 8 cm diameter cone was extended $4\sim7$ mm at 12 MeV electron and the isodose measurements beneath the cone wall showed hot spots as great as $106\%$ for acrylic cone. The leakage radiation dose to tissues outside the cone wall was reduced as $3\sim5\%$ of output dose. A comprehensive set of dosimetric characteristics of the intraoperative radiation therapy applicator system is presented.

• The Korean Journal of Mycology
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• v.16 no.4
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• pp.220-225
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• 1988

This study was carried out to investigate the effect on the system of crop rotation of sesame(Sesamum indicum L). The results of infected plant percentage and yield of sesame wilting disease, fluctuation of density of Fusarium oxysporum and Actinomycetes, and their pathogenicity test on Fusarium spp isolated from sesame cultural soil were investigated. Density of F. oxysporum was the highest in a sesame continuous cropping soil but that of Actinomycetes was the lowest in that soil. And that of F. oxysporum and Actinomycetes according to investigation date was the highest at June. 30 and July. 30, respectively. Their pathogenicity of F. oxysporum and F. solani isolated from sesame cultural soil to sesame, peanut and green gram were recognized to all isolates except one isolate among F. oxysporum 8 isolates and one isolate to sesame, 2 isolates to peanut and all isolates to green gram among F. solani 4 isolates. F. oxysporum density and infected plant of wilting disease were increased as a result of replanted cultivation of sesame, and yield of that was prominantly reduced. Relation between density of F. oxysporum in cultural soil and infected plant percentage showed positive correlation and yield index highly negative. There was little difference between sesame-upland rice and sesame-peanut in the system of crop rotation.

• Journal of the Korean Society of School Health
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• v.12 no.1
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• pp.131-141
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• 1999

The purpose of this study was to serve as a basis for the planning of oral health education and the development of an oral health-promotion program for patients who visited dental clinics by examining how much dental hygienists offered oral health education to adult patients at dental clinics. A parent group was selected, being made up of 1,600 dental hygienists who registered with the Dental Hygienist Association and worked in Seoul. The questionnaire survey was carried out and an ${\chi}^2-test$ was made using the data collected from 218 subjects to determine how their practice of oral health education was different according to certain general characteristics(the sort of organization for which they worked, age, the term of their service, and the mean number of patients per day). As a result, the following findings were obtained: 1. Thees general characteristics made the following differences to the content of oral health, education: The sort of organization for which the subjects worked made a significant difference in the following tooth brushing instruction (p<0.05), the effect of oral prophylaxis or education about aftereffects (p<0.05), the regular examination of prosthesis (p<0.05), smoking-prohibition education (p<0.05), and the prevention poor-quality fillings (p<0.01). The mean number of patients per day made significant differences to the regular examination of prosthesis (p<0.05) and the prevention poor-quality fillings (p<0.01). But no significant disparity was generated by age or the term of service. 2. The general characteristics made the following differences to education about nutrition and diet counseling: The sort of organization for which the subjects worked had a significant effect just on the importance of a balanced menu (p<0.05). Age made significant differences in advice for vitamin, mineral, protein or other nutrients (p<0.01), and the importance of balanced menu (p<0.001). The term of service made significant differences in the importance of balanced menu (p<0.01), and advice for nutrients including vitamin, mineral or protein (p<0.01). 3. The general characteristics made the following differences to the recommendation and use of oral hygiene aids: The sort of oragnization for which they worked made significant differences only to a gingival massager and water pick (p<0.05). No significant difference was produced by age, the term of service or the mean number of patients per day. 4. The use of educational media for oral health was different according to the general characteristics: The use of pamphlets or booklets significantly varied depending on the organization for which they worked and with the mean number of patients per day (p<0.05). The use of slides or slide projectors was significantly affected by age (p<0.05). But no significant disparity was yielded by the term of service. 5. The general characteristics made the following difference as to whether a continued oral management system was carried out or not: The sort of organization for which they worked had very a significant effect on this result (p<0.001), and no significant disparity was made by age, the term of service or the mean number of patients per day. 6. The place where oral health education was giver differed according to the following general characteristics: The sort of organization for which they worked made very a significant difference as to the use of an examination room's dental unit chair or waiting room (p<0.01), and to the use of an oral health education room or reception counter (p<0.001). The term of service had a significant effect on the use of a counseling room (p<0.01). And the mean number of patients per day made significant differences in the use of a dental unit chair or reception counter (p<0.05), and to the use of an oral health education room or waiting room (p<0.01).

• Korean Journal of Agricultural Science
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• v.5 no.2
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• pp.136-144
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• 1978

A series of experiments over three years was planned for practical application of rhizobia in farms and grass lands in Korea. This is the report for the studies of the first year mainly on the isolation and characterization of rhizobial strains, and on the assessment of their nodulation abilities and nitrogen fixation capacities. 1. Total number of 88 strains for soybean group and 22 st ra ins for pea and vetch group was isolated from nodules which were taken from legumes grown in Daekwanyong, Cheju and various places in Korea. 2. Morphological and cultural characteristics of the strains were studied, and attempts were also made to investigate their antigenic properties and to demonstrate lysogenic strains in these groups. The results were : i) the isolates varied in cultural characteristics on yeast mannitol broth and agar, and in degree of congo reel absorption ; ii) similarities in their antigenic properties were found between/among the strains: G-3/G-9/D216, G-20/G-52 in soybean group; iii) no lysogeny was found in the strains of these groups. 3. Plant infection tests by test tube and bottle method in light room were carried out to elucidate the ability of the strains to nodulate specific legumes and of the capacity of such nodules to fix atmospheric nitrogen. The isolates were grouped into non- invasive, ineffective, or effective to the legumes. Those strains which produced effective nodules, supporting similar level of growth as nitrate control, were: P-3, 4 and 8 in pea and vetch group; G-23, 27, and, D-216 in soybean group.

• Sleep Medicine and Psychophysiology
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• v.9 no.1
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• pp.41-47
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• 2002

Objectives: In a number of simulated night shift studies, timed exposure to bright light improves sleep quality and work performance. We evaluated the effect of bright light on adaptation to night shift work with a field study. Methods: Five female nurses working shifts at Korea University Hospital were recruited for participation in this study. We investigated two series of six consecutive shift rotations comprising three day and three night shifts, using wrist Actigraphy, the Stanford Sleepiness Scale, Visual-analogue scales, STIM and tympanic membrane temperature for daytime sleep quality, alertness, subjective feeling, attention performance, and temperature rhythm. The subjects were exposed to bright light (2,500 lux) from 24:00 to 04:00 a.m. on three consecutive night shifts during the second series, whereas they worked under normal lightening (650 lux) conditions during the first series. Results: Actigraphic assessment of daytime sleep showed no significant difference between the first and third night shift in both baseline and light exposure phase. The mean lowest temperature shifted earlier during baseline phase but not during the light exposure phase. Also, the score for subjective feelings of depression, anxiety, physical discomfort and sleepiness was significantly higher in the third night shift than the first during baseline phase but not during the light exposure phase. Attention and attention switching ability was significantly improved in the third night shift compared to the first night during the light exposure phase but there were no significant changes during the baseline phase. Conclusion: This result suggests that there were no significant differences between the two phases in measures of quality of daytime sleep, but subjective feelings, attention and alertness were enhanced during light exposure. Although some placebo effects and learning effects might influence this result, bright light exposure between midnight and 4:00 a.m. may improve adaptation to night shift. In future, further controlled studies with a larger sample size, including melatonin measurement, are needed for real shift workers.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.2
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• pp.270-277
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• 2012

The purpose of this study was to evaluate the importance and satisfaction level foreigners place on human and physical evidence service in Korean restaurants based on nationality such as American/European, Japanese, Chinese, and Southeast Asian. The research was performed by using questionnaires conducted from August to September on 365 foreigners living in Busan. Total mean scores for the importance (3.96/5.00) and satisfaction (3.33/5.00) of Korean restaurant human and physical evidence service were significantly different (p<0.01), as the gap was -0.63. The mean scores of the gap were -1.03 for cleanliness of dining area, -1.01 for cleanliness of tableware, and -0.95 for easily understandable menu board. The mean scores of satisfaction for Southeast Asian individuals (3.77) were significantly (p<0.01) higher than those of American/European (3.40), Chinese (3.37), and Japanese (2.81). The importance and satisfaction grid showed that an easily understandable menu board and a brief description of the food or menu scored high for the importance and low for the satisfaction in American/European, Chinese, and Japanese individuals. Cleanliness of the dining area, cleanliness of tableware, cleanliness of staff appearance, kindness of employees, rapid resolution of complaints, and prompt and quick service scored high for importance and low for satisfaction in Japanese. However, Southeast Asians were satisfied with human and physical evidence service of Korean restaurants.

• Tuberculosis and Respiratory Diseases
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• v.41 no.4
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• pp.328-338
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• 1994

Background: Effect of sulfur dioxide($SO_2$) exposure on airway is well known but little about the effect of $SO_2$ exposure on lung parenchyme. This study is to determine if short tenn exposure to $SO_2$ in concentration commonly found in industrialized environment cause potentially harmful effect on the lung parenchyme, and to evaluate the exposure time-response relationship between short tenn exposure to $SO_2$ and the inflammatory response in mouse lung. Method: 5ppm $SO_2$ gas was used and 48 mice were grouped into control(10), 30(9), 60(11), and 120 minute exposure(18) group. In each group, bronchoalveolar lavage(BAL) was done immediately after and at 1,2,3 days after exposure. Histological examination was performed in control and 120 minute exposure group. Results: 1) Cell response in bronchoalveolar lavage fluid. In 30 and 60 minute exposure group, compared to the control group, lymphocyte count has significantly increased(p<0.05) at 1 day after exposure but did not differ at 2 days after exposure. In 120 minute exposure group, also compared to the control group, there was significant increase in total cell, macrophage, and lymphocyte count at 1 day after exposure, (p<0.05) which lasted for 2 days but did not significantly differ at 3 days after exposure. 2) Histological findings in 120 minute exposure group. In the airway, mild epithelial cell damage and ciliary loss were noted but there was no evidence of inflammatory cell infiltration. Interstitial inflammatory infiltration was noted at 1 day after exposure, which lasted for 3 days after exposure and there was no evidence of edema or fibrosis in the interstitium Conclusions: These data indicate potentially noxious effect of $SO_2$ on the lung parenchyme as well as the airway at exposure level that are regarded as relatively safe, and the duration of injury depends on the exposure time.