• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.12a
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• pp.103-106
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• 2006

Semiconductor laser diode has a reflective facet in a both-ends side fundamentally. Laser performance for improving, Anti-Reflection and High-reflection coating on the facet of semiconductor laser diode. To prevent internal feedback from both facets for realizing superluminescent diode and reducing the reflection-induced intensity noise of laser diode, it's key techniques are AR/HR coatings. In the study AR coating film were manufactured by Ion-Assisted Deposition(IAD) system. Then manufactured coating film measurement electrical properties(L-I-V, Se, Resistor) and Optical properties (wavelength FFP)

• Journal of Environmental Health Sciences
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• v.33 no.2 s.95
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• pp.137-144
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• 2007

Yam, Prunella was stepwise extracted with hexane, chloroform, ethyl acetate, butanol, and water. Anti-microbial activity of each extract was investigated. Hexane extract was tested for anti-microbial effect on Streptocaccus mutans, one of causative factor of dental caries. Methanol extracts of 7 plants were investigated to anti-microbial effects on S. mutans KCTC 5316, P. gingivalis KCTC 5352, S. aureus KCTC 1927 by means of agar diffusion method. Methanol extract of Yam and Prunella revealed anti-microbial activity against S. mutans, P. gingivalis, and S. aureus. Also, hexane fraction of Yam revealed anti-microbial activity against S. mutans. In sequence of hexane, chloroform, ethylacetate, butanol fraction by Prunelia acted as potent anti-microbial agent on P. gingivalis. The measured MIC of hexane fraction of Yam and Prunella on S. mutans KCTC 5316 strain was 0.25 mg/ml and 0.5 mg/ml and the MIC of hexane fraction of Prunella on S. aureus was 0.5 mg/ml. The hexane fraction of Yam and Prunella suppressed viable ceil counts(VCC) of S. mutans, especially after 24 hrs. The Prunella hexane fraction suppressed VCC of S. aureus, after 12 and 24 hrs. Tested concentrations were 0.1, 0.25 and 0.5 mg/ml. the results were compared with control (0 mg/ml). The pH of S. mutans media and GTase activity were determined to evaluate the anticariogenic activity of Yam, Prunella hexane fraction. The pH were increased from 5.6 to 7.0-7.2 in concentration of 2.0 mg/ml. Yam hexane extraction revealed 35% inhibition to GTase activity and Punella inhibited 25% of GTase. These results suggest that the hexane extracts of Yam and prunella have Antibacterial activities against S. mutans, P. gingivalis, S. aureus and have preventive effect on dental caries.

• Physical Therapy Korea
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• v.7 no.3
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• pp.1-18
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• 2000

The present study was performed to investigate the prevalence rate of idiopathic scoliosis and to determine the effect of exercise training on scoliotic angle in elementary school children. In this study, two out of five elementary schools in Seosan city were chosen by random sampling. Seven hundred sixty four students (from four grade to the sixth grade student) were selected in two schools. Screening tests were conducted to find idiopathic scoliosis. Among the 764 individuals, 139 subjects who showed positive sign in physical examination took whole spine radiography. Thirty six subjects who had a curve of 10 or greater and consented to participate in the exercise program were selected for the exercise program. The exercise program was performed four times a week for 5 months. The results of this study were as follows: 1) One hundred thirty nine subjects showed positive sign in the scoliosis screening test. 2) The overall prevalence of curve of $10^{\circ}or$ greater in X-ray finding was 8.15%. The prevalencies of curve of $10^{\circ}or$ greater in male and female were 7.1% and 9.2%, respectively. 3) Scoliosis curves were observed at thoracic area (48.4%), at thoracolumbar area (27.4%) and at lumbar area(24.4%). 4) Right side curve was 59.7%, and left side curve was 40.3%. 5) After the 5 month exercise program for scoliosis, the Cobb's angle was significantly decreased. 6) There was no significant difference of Cobb's angle change respect to sex, grades, and scoliosis curve site. Results shown here indicates that an early detection and early exercise for scoliosis can result in decreased the Cobb's angle in elementary school children.

• Journal of Mushroom
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• v.14 no.3
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• pp.75-80
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• 2016

Morphological and culture characteristics of the novel Phellinus linteus variant KACC93057P collected in Korea were characterized in this study. The surface of the was angular, sessile, tough-woody, concentrically zonate, and dark brown in color. Basidiocarppores were circular, with 5-7 pores per mm. The hyphal system was dimitic, and basidiospores were ellipsoid or oval, $4.5-6{\times}4-5$, exhibiting characteristics typical of P. linteus. The optimum temperature for mycelial growth was $25-30^{\circ}C$, and optimal pH for growth was 5-7. The mycelial growth rate of P. linteus KACC93057P was faster than that of other P. baumii isolates. On growth medium, KACC93057P formed aerial mycelia with density higher than that of other isolates. The internal transcribed spacer (ITS)-ribosomal DNA sequences were closely related to the sequences P. linteus complex.

• Journal of Environmental Health Sciences
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• v.24 no.3
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• pp.99-106
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• 1998

This study was performed to investigate the bioconcentration of dichlorvos, methidathion and phosalone in zebrafish (brachydanio rerio), red sword tail(Xiphophorus hellieri). The fishes were exposed to 0.05 ppm, 0.01 ppm, 0.50 ppm, one-hundredth concentration of 96-hrs LC$_{50}$ and one-thousandth concentration of 96-hrs LC$_{50}$ and test periods were 3, 5 and 8 days. The deputation rate of each pesticide from the whole body of fish was determined over the 24-hr period after treatment. Obtained results are summerized as follows: In the case of dichlorvos, dichlorvos concentration in zebrafish extract and BCF$_{s}$ of dichlorvos were increased as increasing test concentration. In the case of same experimental concentrations, dichlorvos concentration in zebrafish extract and BCF$_{s}$ of dichlorvos were decreased as proloning test periods, especially dropped after 5days. Dichlorvos concentration in red sword tail extract were increased as increasing test concentration, lyat BCF$_{s}$ in concentration of 0.05 ppm, 0.01 ppm and one-hundredth of 96-hrs LC$_{50}$ were decreased. Methidathion and phosalone concentration in zebrafish extract in zebrafish extract were increased as increasing test concentration, but there was little difference in BCF$_{s}$. In the case of same experimental concentrations, there were little differences in BCF$_{s}$ and concentration in zebrafish extract. In the case of red sword tail, it was impossible to calculate on BCF$_{s}$ data because test concentration was under the detecting limit on GC or test fish were die. Determined deputation rate conatant were highest on dichlorvos, and followed by methidathion, and phosalone. The results of determining depuration rate of these pesticides showed that the high BCF in fish might be due to the slow depuration rate in fish, it is thought to be responsible for vapor pressure, water solubility and partition coefficient. It is suggested that one-hundredth concentration of 96-hrs LC$_{50}$ will be proper test concentration because one-thousundth of LC$_{50}$ was under the detecting limit on GC. Dichlorvos, methidathion and phosalone, organophosphorous pesticides, were examined to their BCF$_{s}$ and depuration rates by means of fish test.

• Journal of Environmental Health Sciences
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• v.22 no.1
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• pp.36-44
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• 1996

A comparison was made of two detection methods(UV absorbence detection and fluorescence detection with pre-column derivatization, with trifluoroacetic acid) coupled with HPLC for the simultaneous determination of aflatoxin $B_1, B_2, G_1$ and $G_2$. A good separation of the four aflatoxins was achieved on a reversed-phase $C_{18}$ column (30 cm x 3.9 mm) with methanol-acetonitrile-water(20+20+60) for absorbence detection or acetonitrile-water(25+75) for fluorescence detection at the flow rate of 1.0 ml/min. The calibration graphs were linear over the ranges 100 ppb-1 ppm for $B_1/G_1$ and 30~300 ppb for $B_2/G_1$ with absorbence detection, and 1~500 ppb for $B_1/G_1$ and 0.3~150 ppb for $B_2/G_2$ with fluorescence detection. The correlation coefficients were greater than 0.94 and 0.99 for absorbance detection and for fluorescence detection, respectively. The detection limit was 100 ng for $B_1/G_1$ and 30 ng for $B_2/G_2$ with absorbence detection, and 1 ng for $B_1/G_1$ and 0.3 ng for $B_2/G_2$ with fluorescence detection. Recovery rates of aflatoxin $B_1, B_2, G_1$ and $G_2$ added to yeast-extract sucrose broth medium were 66.6%, 59.4%, 67.5% and 59.2%, respectively, for absorbence detection and 82.9%, 71.5%, 80.0% and 69.3%, respectively, for fluorescence detection. The four aflatoxins in culture medium were quantitatively detected by the two methods. The aflatoxins in the rice sample were not detected the absorbence detection method, but were below 10 ppb using the fluorescence detection method. Analysis of aflatoxins by both the absorbence and fluorescence methods coupled with HPLC showed acceptable linearity and good recovery. The absorbence detection was less timeconsuming and safer for treatment. The fluorescence detection was more elective and sensitive though elevated $B_1$ and $G_1$ contents were determined from the TFA-induced conversion of $B_1$ to $B_{2a}$ and $G_1$ to $G_{2a}$.

• Journal of Environmental Health Sciences
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• v.34 no.1
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• pp.55-61
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• 2008

This study was carried out to investigate the antioxidative and antitumor activities of Saussurea lappa for the purpose of developing a functional food. The methanol extract of Saussurea lappa was fractionated with five solvents (hexane, chloroform, EtOAc, BuOH, water) and examined for antioxidative activities and xanthine oxidase inhibitory activity in addition to growth inhibitory activity of human cancer cell (HT-29, SNU-1, HeLa). Total phenol compound contents were higher in EtOAC fraction than other fractions. Also, electron donating ability was over 90% at $500{\mu}g/ml$ (93.1 %) and $1000{\mu}g/ml$ (94.3%). The hexane fraction revealed stronger nitrite scavenging ability than the positive control (ascorbic acid) and its abilities were 22.4% and 42.8% at $500{\mu}g/ml$ and $1000{\mu}g/ml$, respectively. Xanthine oxidase inhibitory activity had similar tendency to electron donating ability. The EtOAc fraction showed high inhibition to xanthien oxidase activities at $500{\mu}g/ml$(81.9%) and $1000{\mu}g/ml$(90.4%). In the antitumor activity test, the hexane fraction exhibited potent growth inhibition activity against HT-29, SNU-1 and HeLa cells. Therefore, we believe that Saussurea lappa can be developed into a functional food with antioxidant activity. Additional studies are required for the hexane and chloroform fractions of Saussurea lappa to develop them into therapeutic supplements for stomach cancer, colon cancer, and cervical cancer.

• Korean Journal of Health Education and Promotion
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• v.18 no.2
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• pp.141-156
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• 2001

This study was performed to identify the occupational diseases in the dental technicians working in Korea, and to elucidate the main related affecting factors for the occurrence of the occupational diseases. The research was carried out using a mail questionnaire and data collection was done for two months from April 15, 2000. The questionnaires were delivered to 1000 dental technicians working at 250 dental laboratories which were chosen among the total 1330 dental laboratories in south Korea. And 763 questionnaires were collected, then 739 questionnaires were used for a logistic and a multiple regression analyses. The results obtained in this study are summarized as follows: 1. The occupational diseases in the dental technicians included pneumoconiosis, chronic bronchitis, asthma, pneumonia, hyposmia, allergic dermatitis, eczema, contagious dermatitis, central nervous disorder, dysfunction of finger, vertebral disorder, dysfunction of interphalangeal joint, ophthalmitis, auditory dysfunction, otitismedia, optic trauma, and bum. 2. The main related affecting factors for the occurrence of the occupational diseases in the dental technicians were elucidated as follows: On the ccurrence of chronic bronchitis, vibration of equipment and job career were affected positively. On the ccurrence of asthma, job career and career on current working part were affected positively, but exhaust ventilation, work hour were affected negatively. On the occurrence of eczema, career on current working part and vibration of equipment were affected positively, but personal protective equipment, local exhaust ventilation, isolation of gas source were affected negatively. And eczema was occurred more in methyl methacrylate work than in any other work part. On the occurrence of finger dysfunction, vibration of equipment and noise of work place were affected positively. But personal protective equipment, local exhaust ventilation, isolation of dust and gas source were affected negatively. But finger dysfunction was occurred more in metal polishing than in any other work part. On the occurrence of auditory dysfunction, noise of work place were affected negatively. The results obtained in this study can give a valuable information for a prevention of the occupational diseases in the dental technicians working in Korea, and for keeping them in healthy. This study also can be helpful for a researcher who is aiming at a identification of occupational diseases and a elucidation of related affecting factors in a similar occupation.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.2
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• pp.772-779
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• 2010

This study measured the bonding strength of various porcelain prosthesis materials before and after thermocycling to select prosthesis materials that can maximize beauty and tolerance. To measure bonding strength, various porcelain materials were baked on with-Beryllium metals, non-Beryllium metals 8group and Zirconia 1 group among commercially available base alloys, and measured the bonding strength was measured before and after thermocycling. The findings of this study are as follows: 1) PTM(press-to-metal) porcelain non-Beryllium metal showed the, highteat bonding strength each 73.2MPa, 59.2MPa before and after thermocycling. 2) The porcelain materials baked on non-Beryllium metal showed higher bonding strength before and after thermocycling than those baked on with-Beryllium metal. 3) Zirconia products showed the lowest 38.7MPa bonding strength before and after thermocycling.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.2
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• pp.758-764
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• 2010

This study showed effective and new applicative direction of CRM of medical management after arranging CRM researches, measuring CRM activity and the results of medical institutions and clearing factors having an effect. In other words, 'Human Factors' variables and 'Physical Factors' variables have an effect on the result of CRM. 'Human Factors' variables have an effect on the qualitative result and 'Physical Factors' variables have an effect on the quantitative performance. In more strategic CRM continuum, Human Factors have a significant effect on the whole performance of CRM. And in more tactical, CRM continuum Human Factors and Physical Factors have significant effect on the whole performance of CRM. Consequently, The key point is grasp of what characteristics exist in CRM between strategic level and tactical level. This provides the foundation for the variables in marketing practice.