• Membrane Journal
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• v.12 no.1
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• pp.41-50
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• 2002

The streaming potential generated by the electrokinetic flow within electric double layer of charged microchannel is applied to determine the zeta potential of hollow-fiber membrane pore by using the general Helmholtz-Smoluchowski equation. The streaming potential is know to provide a useful real-time information on the surface property and the interaction between pore and particles in actual situations and physicochemical conditions. The influence of physicochemical parameters upon the filtration with hollow-fibers has been examined with an in-situ and simultaneously monitoring the streaming potential as well as permeate flux. In particular, the present study examined an experimental method to identify the effect of cake layer which can vary according to the axial position of a hollow-fiber and the progress of membrane fouling by measuring the position-dependent streaming potential. As the latex concentration increases, the permeate flux decreased but the streaming potential increased. The growth of cake layer has been mire developed with increasing latex concentration, however, the effect of surface charges of latexes deposited on the membrane surface leads to increase the streaming potential. With increasing ionic concentration of KCI, both the permeate flux and the streaming potential decrease. The increase of ionic concentration provides a compact cake layer due to the shrinkage of Debye length and the decreased streaming potential results from the weakened ionic flows owing to a thin diffusive double layer.

• KASI NEWSLETTER
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• s.50
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• pp.1-4
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• 2005

기숙사 신축공사 기공식/ 2004년 기관평가 결과 : '보통'/ 연구원 STRM 워크샵 개최/ 멕시코와 초대형 망원경 건설 공동협력　의향서 체결/ 대형망원경 건설 사업 과제 제안서 공모/ 삼국시대 일식도 발간/ 제13회 천체사진공모전 당선작 선정 및 시상/ 2005 별의 축제 개최/ 제2회 보현산별빛문화축제 개최/ 직원동정/ 학회동정/ 콜로키움/ 과학기술위성 1호 FIMS (원자외선 우주망원경) 관측

• Journal of the Korea Convergence Society
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• v.2 no.1
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• pp.31-36
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• 2011

This study was performed to investigate the problems of using asbestos for dental technicians. Samples for analysing were sampled by personal sampler in 40 sampling points of 10 dental laboratories in Daegu city from December 2010 to January 2011 and counted with phase contrast microscopy. The results were as follows: 1. Asbestos concentration(geometric mean) of 40 sampling points in 10 dental laboratories was 0.0061 f/cc and it was under recommended industrial and indoor air standard, but the concentration of asbestos in only two dental laboratories was over indoor recommended standard. 2. The concentration of asbestos in processing room and burnout room was 0.0099 f/cc and 0.0037 f/cc, respectively. 3. The mean concentration(GM) of asbestos by kinds of casting ring liners was 0.0159 f/cc in dental laboratories using industrial asbestos, 0.0104 f/cc in them using asbestos containing ring liners, and 0.0026 f/cc in them using non-asbestos ring liners. Casting ring liners using in dental laboratories should be substituted with non-asbestos liners, because most of dental laboratories were using asbestos containing ring liners and a few of them showed higher concentration than recommended standard.

• The Journal of the Korea Contents Association
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• v.11 no.10
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• pp.355-369
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• 2011

The purpose of this study was to determine the subjective symptoms of respiratory disease and factors related to prevalent status among dental technicians by analyzing the questionnaire data from 300 dental technicians in Seoul and GyeongGi-Do, using SPSS WIN 18.0 program. The results are followings; 1. There were significant differences among subjects in the normal complaints rate for cough by presence smoking, total career, and work days per week. 2. There was significant difference among subjects in the normal complaints rate for sputum only by work days per week.(P<0.05) 3. There were significant differences among subjects in the normal complaints rate for continuance of sputum or congestion by work days per week and required measures for improvement in pain. 4. There were significant differences among subjects in the normal complaints rates for blocked nose and coryza by sex, age, work days per week and average length of breaking time during working (P<0.05). 5. There were significant differences among subjects in the normal complaints rates for shortness of breath by sex, exercise frequency, average length of exercise, main job. 6. There was significant difference among subjects in the experience rate due to symptom of pulmonary disease only by main job.(P<0.05).

• Membrane Journal
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• v.28 no.6
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• pp.395-405
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• 2018

Poly(ethylene-co-vinylalcohol) EVOH hollow fiber membranes were successfully fabricated via a thermally induced phase separation (TIPS) method. It was observed that all membranes fabricated under different spinning conditions had interconnected and bicontinuous structures through liquid-liquid phase separation. Glycerol and poly(ethylene glycol) 200 were used as diluents for the TIPS method. Glycerol was used as a mixing component in quenching bath to control pores on the outer surface of the hollow fiber membrane. Hot quenching bath with a mixing component to generate large pores on the outer surface of the hollow fiber membrane. The effects of polymer concentration, diluent and quenching bath on the morphologies, water permeabilities, and mechanical properties of the EVOH hollow fiber membranes were systematically investigated. The relationship between water permeability, mechanical properties and spinning conditions was discussed in detail.

• Journal of the Korean Academy of Esthetic Dentistry
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• v.27 no.2
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• pp.105-115
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• 2018

Not to recreate the final prosthesis is the shortest way to get a successful outcome. In the case of an aesthetic prosthesis, it is important not only the condition of the oral cavity but also the whole harmony in the face such as the interpupillary line and the smile line. But the dental technician creates the prosthesis only based on the oral model. So if you want to prevent the failure of the prosthesis due to discordance with the face, it is a good idea to use patient's facial photography and provisional restorations to reproduce facial features, shapes and aesthetics before switching to a final prosthesis. To prevent the failure of the final prosthesis, it is important to communicate among the patient, the technician and the doctor according to the model diagnosis, facial and oral photos. Then all the technicians will get satisfactory results. In addition, the technician have to understand the form of natural teeth, to analyze and reproduce colors, and to understand materials in order to produce a successful aesthetic prosthesis. From now on, I will explain two parts. At first, the communication in the dental office for the successful production of aesthetic prosthesis through the clinical case. And the second, my opinion for the successful aesthetic prosthesis.

• Journal of the Korea Convergence Society
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• v.6 no.4
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• pp.153-159
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• 2015

Dental assistant in South Korea, The work is overlapped considerably between dental hygienist and dental practical nurse. Moreover, dental technician, hospital coordinator work in dentistry consultation deeply. It cause friction among work scope of occupation's type. Accordingly It is purpose to get basic data which is necessary to deduce division of work training and utilization of human resources in oral health distinguish clearly between business occupations. Also compared and analyzed via analysis of frequency and ANOVA above 10 works around something legal work of dental hygienist regarding work reality of dental assistant in dental clinic and hospital. Compare with scaling, representative item about 10 works center on legal work of dental hygienist, is implementing dental technician 9(75%), practical nurse 64(87.67%), etc. 11(64.71%). Dental assistant except dental hygienist is implementing indigenous legal work of dental hygienist. Dental institution secure enough man power, It is suggested necessity for policy means regarding role and work scope of dental assistant.

• Journal of Technologic Dentistry
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• v.36 no.1
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• pp.39-49
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• 2014

Purpose: The purpose of this study is to investigate the improvement measures of dental technician practical examinations. Methods: A survey was performed on 37 professors through a questionnaire. The results were analyzed by SPSS 12.0. The collected data was analyzed by frequency and the chi-square test. Results: The education compared to the satisfaction of practice examinations only differs in the method of enforcement(p<.05). The evaluations on the ability to perform the job with practical subjects were inadequate (37.8%). Questions with the most necessary work tools through the articulator was highest at 48.7%, Electric wax carver was 32.4%, and heating clear was 3.5%. Conclusion: There must be an improvement to increase the cooperation within the clinical department, while considering the practical exam environment.

• Journal of Technologic Dentistry
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• v.19 no.1
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• pp.63-89
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• 1997

This survey aimed at the analysis of the consciousness of the dental technicians on the college education ; 205 dental technicians who graduated the relavant school answered. Following is the result of the analysis with its ststistcal number. 1. About the time when they chose their major, 84 people(41.1%) answered the prepartion period for the college. And, 74(36.1%) said that they applied on their own thought to their major. The reason why they chose it was first the prosperity expected in the near future, 93(45.4%) replied. 2. 161(78.5%) were satisfied with their college days. On the other hand, the most regretful one those days, 69(33.7%) answered, was the scarcity of the study seminar. 3. About the exercise courses, 120(58.6%) showed dissatisfaction, and 66(32.3%) people of the dissatisfied pointed out the lack of the instruments. 4. The suitable number in a class, 124(60.5%) supported, is 20 heads. The appropriate period of education was said three years by 71(34.6%), four years 53(25.9%) and the extension to the graduate school by 41(20.0%) 5. About the tips for the professors, 147(71.7%) proposed they would research and lecture further more. To the college administration, 116(56.5%) suggested it should accomo-data enough instruments for practicing.

• Journal of Technologic Dentistry
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• v.44 no.3
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• pp.104-110
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• 2022

Purpose: This study analyzes the difficulty and discrimination of the paper-based test (PBT) and the computer-based test (CBT) according to item response theory, focusing on the National Dental Technician Examination. Methods: A mock test was conducted from September 15 to 23, 2020, and the final 179 (1 out of 180 absentees)people were the subjects of this study. Both frequency analysis and factor analysis were performed. The collected data were analyzed using IBM SPSS Statistics ver. 18.0 (IBM) and jMetrik programs. The significance level was set to 0.05. Results: The difficulty of the mock test was more easily responded to in CBT. It was also predicted that the CBT could better measure the ability of test takers than the PBT could. Conclusion: The difficulty, discrimination, and reliability of the questions were not affected by the examination method through the mock test. The feasibility of a future change to the CBT was confirmed by the National Dental Technician Examination.