• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.13 no.6
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• pp.526-532
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• 2000

The paste on the glass or fabrication of the PDP(Plasma Display Panel) barrier rib was selectively etched using focused A $r_{+}$ laser(λ=514 nm) and Nd:YAG(λ=532, 266 nm) laser irradiation. The depth of the etched grooves increase with increasing a laser fluence and decreasing a laser beam scan speed. Using second harmonic of Nd:YAG laser(532 nm) the etching threshold laser fluence was 6.5 mJ/c $m^2$ for the sample of PDP barrier rib. The thickness of 180 ${\mu}{\textrm}{m}$ of the sample on the glass was clearly removed without any damage on the glass substrate by fluence of 19.5J/c $m^2$beam scan speed of 20${\mu}{\textrm}{m}$ /s. In order to increase the etch rate of the barrier rib material barrier rib samples heated by a resistive heater during laser irradiation. The heated sample has many defects and becomes to be fragile. This imperfection of the structure compared to the sample without heat treatment allows the effective etching by the focused laser beam. The etch rates were 65${\mu}{\textrm}{m}$/s and 270 ${\mu}{\textrm}{m}$/s at room temperature and 20$0^{\circ}C$, respectively.y.

• Proceedings of the KWS Conference
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• 2002.10a
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• pp.187-192
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• 2002

Applicability of laser micro welding process to the fabrication of medical devices was investigated. Austenitic stainless steel wire (SUS304) was spot melted and crosswise welded, which is one of the most possible welding process for the fabrication of medical devices, by using a Nd-YAG laser. Effects of welding parameters on the microstructure, tensile strength and corrosion resistance were discussed. In the spot melting, melted metal width decreased with decreasing the input energy and pulse duration. Controlling the laser wave to reduce laser noise which occurred in the early stage of laser irradiation made reasonable welding condition wider in the welding condition of small pulse duration such as 2ms. The microstructure of the melted metal was a cellular dendrite structure and the cell size of the weld metal was about 0.5~3.5 ${\mu}{\textrm}{m}$. Tensile strength increased with the decrease of the melted metal width and reached to a maximum about 660MPa, which is comparable with that for the tempered base metal. Even by immersion test at 318K for 3600ks in quasi biological environment (0.9% NaCl), microstructure of the melted metal and tensile strength hardly changed from those for as melted material. In the crosswise welding, joints morphologies were classified into 3 types by the melting state of lower wire. Fracture load increased with input energy and melted area of lower wire, and reached to a maximum about 80N. However, when input energy was further increased and lower wire was fully melted, fracture load decreased due to the burn out of weld metal.

• Journal of The Korean Association For Science Education
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• v.15 no.1
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• pp.116-125
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• 1995

This study is to consider hypotheses with integral view on the respect of creative thinking. Subjects of this study are Korean students in the 5th grade who participated in the Field Trip Contest of the second Korean Youth Science Festival, an openended inquiry investigation. Objectives of this study are as follows: 1) to measure the inquiry level of the Field Trip Contest activity 2) to find how many hypotheses were made on different types in the inquiry investigation 3) to measure the quality level of hypotheses made in the scientific inquiry investigation 4) to find out the correlation between the 1st and 2nd hypotheses and the final activity score in the two staged scientific investigation In the consequence of it, inquiry level of the Field Trip Contest was very high with good activity topics and openended way of investigation. Hypotheses were made in the prediction, plan, and conclusion parts in the field trip activity report. They used hypothesis-as-prediction typed statements(3.41/team) more than hypothesis-as-explanation(1.28/team) and descriptive hypothesis(0.03/team) types. Content-related hypothesis(5.03/team) and process-related hypothesis(6.16/team) were usually coupled each other. Most of them had difficulties in hypothesis-from-evidence(0.31/team, 10/32 teams) in the comparison of hypothesis-from-simple conjecture(10.62/team). The quality level of content-related hypotheses(0.74point/statement) and process-related hypotheses(1.98point/statement) were very low by the hypothesis-quality scale(Quinn and George, 1975) for the content-related hypotheses and the process-related hypothesis quality scale developed in this study. There was considerable correlation between the activity score and the 1st and 2nd hypothesis in the 2 staged inquiry investigations with the 2nd and 3rd topics($0.41{\ast}$, $0.59{\ast}{\ast}$ repectively).

• Maxillofacial Plastic and Reconstructive Surgery
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• v.31 no.6
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• pp.510-518
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• 2009

Purpose: In this study, we analyzed and compared the anatomical position of the mandibular canal in normal occlusion and mandibular prognathism patients. Patients and Methods: Computed tomography image from 58 patients were divided into normal occlusion group and mandibular prognathism group, and each measurement were taken in the each measuring points(2nd premolar, 1st molar, 2nd molar, 3rd molar, ramus). Measurements were statistically analyzed by student's t-test. Results: BC (Thickness of the buccal cortex) value was 2.3~2.7 mm, CB (Distance from the canal to the lingual aspect of the buccal cortex) value was 1.3~4.3 mm, MC (Diameter of the canal) value was 3.2~3.8 mm, LI (Distance from the canal to the lingual aspect of the lingual cortex) value was 2.0~3.7 mm, TM (Thickness of the total mandible) value was 9.5~12.9 mm and CM (Distance from the canal to the inferior border of the mandible) value was 6.9~17.5 mm. Conclusion: In the comparison between two groups, there was statistically significant difference in CB value of 2nd, 3rd molar between normal occlusion and mandibular prognathism, and other value in the rest of the measuring points didn't show statistically significant difference.

• Korean Journal of Biological Psychiatry
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• v.5 no.1
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• pp.114-121
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• 1998

Bethanechol, a cholinergic agonist, has been recommended for the management of peripheral anticholinergic side effects during the treatment of antipsychotic medications. But there have been few studies which have evaluated the drug interactions of antipsychotics and bethanechol, even the treatment effects of bethanechol on anticholinergic side effects. So the authors have evaluated whether psychopathology and plasma haloperidol and reduced haloperidol concentrations are significantly changed or not when bethanechol was administrated with maintained doses of haloperidol and other coadministrated drugs(such a benztropine). Also we have evaluated the abating effects of bethanechol on anticholinergic side effects during the treatment with haloperidol. Fifteen schizophrenics with higher than 5 of total score of anticholinergic side effects of 'Rating scale for side effect' were assigned to two groups, and bethanechol 30mg/day and 60mg/day were applied on each group for 4 weeks. The daily haloperidol dosages were fixed before 2 weeks of study. We assessed anticholinergic side effects by 'Rating scale for side effect' and psychopathology by BPRS, and plasma haloperidol and reduced haloperidol concentrations by HPLC at baseline, 2nd week and 4th week. The results were as followed, 1) there was no significant change of plasma haloperidol and reduced haloperidol concentration, 2) at baseline, the dosage of haloperidol showed significant correlation with the total score of anticholinergic side effect, but not at 2nd week and 4th week, 3) in 60mg/day group, dry mouth and the total score of anticholinergic side effects were significantly improved, but not in 30mg/day group, 4) there was no significant change of BPRS except withdrawal at 2nd week. These results suggest that coadministration of bethanechol influenced neither on psychopathology nor on plasma haloperidol and reduced haloperidol concentrations and that improved dry mouth and total score of anticholinergic side effects at 60mg/day.

• The Korean Journal of Food And Nutrition
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• v.27 no.5
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• pp.837-844
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• 2014

This study was carried out to analyze the differences in p-hydroxylbenzyl alcohol (HBA) content, antitumor and anti-obesity activities and tyrosinase inhibitory activity between non-fermented G. elata (NFGP) and fermented G. elata powder. The HBA content, which is an index-component of G. elata decreased from 1.58 mg/g before fermentation to 1.07, 0.32, and 0.13 mg/g after the $1^{st}$ fermentation ($1^{st}$ FGP), $2^{nd}$ fermentation ($2^{nd}$ FGP) and $3^{rd}$ fermentation ($3^{rd}$ FGP), respectively. The anti-proliferation effects on the cell lines HT29 and AGS were significantly higher for the fermented G. elata than the NFGP. The antitumor activity was also increased in a fermentation number-dependent manner. During adipocyte differentiation, the ethanol extract of the $3^{rd}$ FGP inhibited lipid accumulation in 3T3-L1 cells significantly better than NFGP and the $1^{st}$ FGP, treated at the concentration of $10{\mu}g/mL$. The tyrosinase inhibitory activity of the $2^{nd}$ FGP at $600{\mu}g/mL$ over was higher than that of kojic acid. At the concentration of $1,000{\mu}g/mL$, the tyrosinase inhibitory activity was increased in a fermentation number-dependent manner. From these results, the fermented G. elata, especially the $3^{rd}$ FGP, is expected to be good candidate for the development of functional food and agents with antitumor, anti-obesity, and tyrosinase inhibitory potential.

• The Journal of Korean Society of Virology
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• v.30 no.1
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• pp.11-18
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• 2000

Since $Hantavax^{TM}$, formalin inactivated Hantaan virus vaccine (10,240 ELISA units/ml), has been developed in 1990 to prevent against haemorrhagic fever with renal syndrome (HFRS) caused by Hantaan or Seoul virus, it has been commercially available in Korea. Twenty-one healthy people were booster shot once and twice after primary basic vaccination with $Hantavax^{TM}$. Seroconversion rates were measured by immunofluorescent antibody technique (IFAT), enzyme-linked immunosorbent assay (ELISA), high density composite particle agglutination (HDPA), and plaque reduction neutralization test (PRNT). Seroconversion rates of 21 vaccinees at one year after primary basic vaccination were 52.3%, 95.2%, 0.0%, 47.6%, and 28.6%, and 13 vaccinees at one month after 1st booster vaccination were 100%, 100%, 30.7%, 100% and 100% by IFAT, ELISA (IgG, IgM), HDPA and PRNT, respectively. Seroconversion rates declined slightly by twenty months, and they were 84.6%, 92.3%, 0.0%, 84.6% and 69.2% by IFAT, ELISA (IgG, IgM), HDPA and PRNT, respectively. Seroconversion rates of 9 vaccinees at three months after 2nd booster vaccination were 100%, 100%, 0.0%, 100%, and 88.9%, and 16 vaccinees at one year after the 2nd booster vaccination were 87.5%, 93.8%, 0.0%, 87.5% and 81.3% by IFAT, ELISA (IgG, IgM), HDPA and PRNT, respectively. Based on the above result $Hantavax^{TM}$ has proved a vigorous anamnestic response after the 1st and the 2nd booster vaccination and has persisted higher fluorescence, agglutination and neutralizing antibody titers in vaccinees.

• Korean Journal of Veterinary Service
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• v.13 no.1
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• pp.96-102
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• 1990

The immune responses of commercial layer chickens against Newcastle disease(ND) were compared among different administration methods and times of vaccination during 4 weeks of age. A total of 372 day-old chickens were divided into 4 groups of 93 birds each. Each of 3 groups was received a commercially available B$_1$live vaccine via drinking water, eye instillation or spray method at one, 14 and 28 days of age. One group was used as an unvaccinated control. At two and 4 weeks after each time of vaccination, 15 birds from each group were collected randomly out and challenged with virulent ND virus at the dose of $10^5E1D_{50}$ per bird. Ten to 15 birds from each group were bled at two weeks intervals from day old to 8 weeks of age for hemagglutination inhibition antibody titer, The protection rate was generally low regardless of the times of vaccination although two or more times vaccination gave higher protection than once vaccination. The low protection was considered due to low titer of the vaccine used since the vaccine titer was less than $10^{3.5}EID_{50}$ per bird. Spray method gave better protection compared to eye instillation or drinking water method which resulted in lowest response. Majority of birds showed clinical signs of ND between 3 and 6 days after challenge. Death occured one or two days after onset of symptoms. Major clinical signs observed were depression(94%), anorexia(84%), diarrhoea(29%), difficult breath(15%) and torticollis(10%). Hemorrhagic lesions on post mortem were seen in duodenum(51%), trachea(35%), illeum(13%), ceacal tonsil(11%), proventriculus(10%) and some other odrgans.

• Journal of the Korean institute of surface engineering
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• v.41 no.2
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• pp.57-62
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• 2008

Electrochemical properties of Ti-30Ta-$(3{\sim}15)$Nb alloys coated by HA/Ti compound layer have been studied by various electrochemical method. Ti-30Ta binary alloys contained 3, 7, 10, and 15 wt% Nb contents were manufactured by the vacuum furnace system. The specimens were homogenized for 24 hrs at $1000^{\circ}C$. The samples were cut and polished for corrosion test and coating. It was coated with HA/Ti compound layer by magnetron sputter. The HA/Ti non-coated and coated morphology of Ti alloy were analyzed by x-ray diffractometer(XRD) and filed emission scanning electron microscope(FE-SEM). The corrosion behaviors were investigated using potentiodynamic method in 0.9% NaCl solution at $36.5{\pm}1^{\circ}C$. The homoginazed Ti-30Ta-$(3{\sim}15wt%$)Nb alloys showed the ${\alpha}+{\beta}$ phase, and ${\beta}$ phase peak was predominantly appeared with increasing Nb content. The microstructure of Ti alloy was transformed from needle-like structure to equiaxed structure as Nb content increased. HA/Ti composite surface showed uniform coating layer with 750 nm thickness. The corrosion resistance of HA/Ti composite coated Ti-alloys were higher than those of the non-coated samples in 0.9% NaCl solution at $36.5{\pm}1^{\circ}C$. Especially, corrosion resistance of Ti-Ta-Nb system increased as Nb content increased.

• Fire Science and Engineering
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• v.32 no.5
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• pp.57-66
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• 2018

A sports center fire in Jecheon that caused 29 deaths and 40 injuries was analyzed based on initial response and management in order to investigate the causes of the casualties. The aspects of initial response included delay of reporting 119, not being guided to the exit for the body scrubber on the $2^{nd}$ floor for escape, opening the fire doors of the exits on the $1^{st}$ floor and $3^{rd}$ floor, not closing the fire door of the main stairs on the $3^{rd}$ floor, and not doing an emergency broadcast. The management aspects included closing the alarm valve of the sprinkler system on the $1^{st}$ floor, starting-stop of the fire pump controller, neglecting leakage of water and electricity between the false ceiling and ceiling in the parking lot, hiding the exit light in the ladies bathroom lounge on the $2^{nd}$ floor and piling up things in the exit, neglecting the button of an automatic door on the $2^{nd}$ floor, conventional fire safety management, insufficient inspection of fire equipment, and not working fire shutters and smoke exhaust windows.