• Restorative Dentistry and Endodontics
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• 제8권1호
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• pp.133-137
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• 1982

Radiography is one of the important tool adopted in daily dental practice and medical diagnosis. To visualize soft tissuechange various contrast media has Been introduced. Any cavity or space can be easily determined by increasing the X-ray absorption of the cavity using the radiopaque contrast media which widely employed in medical radiography to show much of the digestive, cardiovascular, pulmonary, and renal system. The essential part of any radiopaque medium is a heavy element that can absoarb most of the X-ray beam. The element must be noninjurious and easily eliminated. Both aqueous and oil suspensions of iodine containing compounds' are available to the dental profession, for example Lipiodol and Dionosil. The study was designed to determine toxic effect of Lipiodol to the vital pulp and to confirm visualization ioprovement in pulp canal. 1. Thin mixture of Calcium hydroxide and Lipiodol was applied to 19 deep vital cavities for 24 hours. Only one case complained slight pain for short time. 2. Cotton pellet over-saturated in Lipiodol was inserted in coronal chamber of which 6 were non vital and 5 were vital. The transference of Lipiodol was not noticed in every case after 24 hours. 5 cases with vital pulp tissue in the canals showed no clinical symptome. 3. Extracted 20 teeth were routinely prepared for endodontic treatment and applied Lipiodol in conjunction with cotton fiber as deep as midportion of the roots. After 24, hours the medicament reached to nearly the end of apex, but there were no evidence of penetration in dentine layer and migrate into ramified canal.

• Restorative Dentistry and Endodontics
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• 제15권1호
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• pp.20-32
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• 1990

The plane strain fracture toughness of a material characterize the resistance to fracture in the presence of a sharp crack under severe tensile condition. Fracture toughness can be determined by indentation method. The purpose of this study was to investigate the fracture toughness of dental amalgams by measuring the plane strain fracture toughness and the fracture toughness from indentation method. Two conventional and four high copper amalgam alloys were employed for this study. The amalgams were prepared according to the A.D.A. spec. No. 1 and inserted into the specially designed mould with the single edge notch specimen to use in 3-point bending method. The specimens (20mm long, 4mm wide, 2mm thick) were stored at $37^{\circ}C$ for 1 week, and tested in 3-point bending by means of Instron at a cross-head speed of 1mm/min. In indentation method, the specimens were made in same manner as single edge notch specimens. The test was conducted with Vickers hardness tester at 10kg load. The following results were obtained. 1. The plane strain fracture toughness and the fracture toughness from indentation method were higher in the low copper amalgams than the high copper amalgams. 2. In high copper amalgams, the fracture toughness of amalgams decreases according as the copper contents increase. 3. In similar copper contents, the single composition amalgams have a higher fracture toughness than the admixed amalgams.

• Restorative Dentistry and Endodontics
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• 제16권1호
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• pp.25-40
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• 1991

Four root canal sealers, Apatite Root Sealer I and II composed mainly of hydroxyapatite/tricalciumphosphate, Sealapex containing calcium hydroxide, and Roth Sealer composed of zinc oxide - eugenol were compared on the culture of L929 fibroblasts. MIT (Methyl Thiazole Tetrazolium Bromide) colorimetric technique was used to measure the mitochondrial dehydrogenase activity. Results were as follows: 1. Hydroxyapatite/tricalcium phosphate mixed sealers were significantly less toxic compared with calcium hydroxide and zinc oxide - eugenol type sealers. High pH of the calcium hydroxide sealer and release of eugenol component from the zinc oxide - eugenol type sealer were presumed to be the cause of the toxicity of these two sealers. In no cases, there were more cytoblastic effects in hydroxyapatite/tricalcium phosphate mixed sealers compared to the control groups. 2. In all experimental groups, toxicity was decreased as dilutions were increased. However in zinc oxide-eugenol type sealer the cell activity was weakened for all dilution groups. 3. Regarding the effect of setting time, Apatite I and Sealapex were less toxic as the setting progressed. Apatite II kept constant regardless of the different time ellapsed after setting but Roth sealer revealed significantly higher toxicity for all experimental groups. 4. Comparing two different culture periods of 24 hours and 72 hours, Apatite I showed higher cell activities in longer period(72 hours) while Apatite II did not. Sealapex and Roth sealer, however, showed significantly lower cell activities in longer period.

• Restorative Dentistry and Endodontics
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• 제10권1호
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• pp.161-168
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• 1984

The purpose of this study was to examine the effect of heat generated by rotating bur on the dental hard tissue in vitro. Freshly extracted molar teeth with normal appearance from early 20's male were collected and experimental teeth were divided into 4 groups and the teeth in each group were prepared class I cavity with different clinical procedures as follows. The four methods were. I. 20,000rpm without coolant II. 20,000rpm with coolant III. 500,000rpm without coolant IV. 500,000rpm with coolant Five teeth were reserved intact as a control group. These teeth were longitudinally split into two parts by means of chisel after class I cavity preparation. In a control group 5 parts were boiled in water for 20 minutes and the other 5 specimens were not boiled. All specimens were immersed in 2% methylene blue dye solution and the image of dye penetration was examined and photographed under stereomicroscope. Followings were the results obtained through the study. 1. In control group, dye penetration of the unboiled specimens was increased than with the boiled group. 2. The specimens prepared cavity without coolant showed decreased dye penetration than with the coolant group. 3. 20,000rpm without coolant group showed the least dye penetration. 4. 500,000rpm with coolant group showed similar level of dye penetration to the unboiled specimens from the control group.

• 한국GIS학회:학술대회논문집
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• 한국GIS학회 2004년도 GIS/RS 공동 춘계학술대회 논문집
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• pp.429-434
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• 2004

현재 우리나라는 육역에 대한 조사와 영해관리를 위한 조사는 이루어져 있으나 연안해역에 대한 해저정보조사는 부족한 실정이다. 비록 국토지리정보원은 1976년부터 연안 해역기본도를 제작 및 배포하고 있으나 갱신주기가 매우 길며, 소축척으로 제작하여 정확도가 낮다. 따라서 해양수산행정 서비스를 위한 기초 자료가 매우 부족한 실정이다. 그리고 NGIS와 MGIS(해양수산부에서 추진하고 있는 해양 GIS사업)와의 연계를 위해 해양 분야에 대한 국가기본지리정보 D/B를 구축하여 디지털 국토 완성할 필요성이 있다. 관련법규를 조사하여 연안해역 해저정보의 조사 필요성과 타당성에 대해 법적인 근거를 마련하였고, 과거 진행되어왔던 연안관련 사업에 대한 조사를 현재 제작되거나 제작중에 있는 자료의 종류와 정확도에 대해 조사하고, 이미 제작된 자료의 문제점에 대해분석 하였다. 효과적인 연안해역 해저정보조사를 위해 우리나라 연안을 아래 그림과 같이 10개 권역으로 구분하고, 이를 다시 7.5'x 7.5'의 소구역으로 구분한 후 각 소구역의 중요도에 따라서 등급을 부여하고, 각 등급별로 IHO S-44 기준의 관측정확도를 따르도록 하였다. 또한 자료조사항목을 선정하여 중요도가 높은 조사항목에 대해 우선적으로 조사할 수 있도록 하였다. 연안해역 해저정보에 대한 조사가 이루어지면 연안 행정 업무 효율성 증대되고 긴급상황에 대처한 신속한 의사결정 가능하며, 다양한 자료의 복합적인 분석 가능할 것이다. 또한 NGIS와 MGIS를 연계하여 많은 부가가치를 창출할 수 있을 것이라 예상된다.

• 정보교육학회논문지
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• 제17권4호
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• pp.467-474
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• 2013

본 연구에서는 STEAM 교육과 미래 유망직종인 사이버네트워크 전문가의 교육활용 연구 사례를 살펴보고 이를 토대로 초등학교 3-4학년을 위한 사이버 네트워크 주제 STEAM 진로 교육프로그램과 수업 방안을 제시한다. 3-4학년의 지적 발달 수준과 흥미를 고려하여 교육프로그램을 구성하고 이에 따른 교재와 교사용 지도서를 개발하였다. 개발된 교재의 실효성을 검증하기 위해 제주도내 3-4학년 학생을 대상으로 단계별로 교육을 진행하였으며, 향후 추적연구 및 확대 적용도 이루어질 예정이다. 본 연구에서 제공하는 사이버 네트워크 주제 STEAM 진로 교육프로그램을 지도함으로써 IT관련 진로 탐색과 관련 소양 발달에 좋은 효과를 얻을 수 있을 것으로 기대된다.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2018년도 추계학술대회
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• pp.167-169
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• 2018

2020년부터 전 세계적으로 IMO 선박연료유 규정은 한층 강화될 것으로 예상되며, 일부 지역은 배출규제해역(Emission Control Area; ECA)를 지정하여 선박으로부터 배출되는 대기오염물질을 통제하고 있다. 우리나라는 항만도시의 대기오염 정도가 높으며 대기오염물질의 주요 배출원은 선박으로 밝혀지고 있어 이에 대한 대책으로써 ECA 지정을 위한 검토가 시급하다. 본 연구에서는 국내 항만을 대상으로 ECA 지정 필요성을 검토하고 우리나라 여건에 적합한 ECA 지정방식과 절차 등 종합적인 도입방안을 제시하는 것을 목적으로 한다. 연구목적 달성을 위해 우리나라 항만도시의 대기환경 현황을 분석하고, 해외 ECA 지정 사례 분석을 통해 그 지정현황, 규제 수준 및 효과를 파악하였다. 또한 ECA 도입 타당성을 제시하기 위해 항만도시 거주민과 업계 종사자를 대상으로 수행한 설문조사 결과를 활용하였다. 결과적으로, 우리나라의 ECA 도입은 필요하며 향후 5년을 목표로 단계적으로 추진하는 것이 바람직하다. 우선적으로 자발적으로 영해 내 ECA 도입을 추진하되, 선박 통항량이 많은 주요항만구역을 대상으로 한다. 제도의 초기 장착을 위한 인센티브 제도 마련, 관리인력 확보 및 법 제도 구축을 통해 실효성을 확보하도록 해야 한다. 장기적으로는 IMO 승인을 통해 ECA가 이행될 수 있도록 타당성 조사가 선행되어야 한다.

• 지역사회간호학회지
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• 제20권2호
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• pp.169-178
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• 2009

Purpose: This study was conducted to find perceived health status, ADL, depression, and life satisfaction among the rural elderly and to explore differences according to gender and the stage of exercise change. Methods: This is an exploratory survey study. The subjects were 365 elders consisting of 140 men (38.4%) and 225 women (61.6%) in a rural area in Korea. Data were collected from December, 2006 to January, 2007 using a structured questionnaire. The data were analyzed by Pearson's correlation, t-test, ANOVA, and Scheffe's test using the SPSS/WIN 10.0. Results: The mean scores of perceived health status and ADL were lower and depression was higher in women than in men. There were statistically significant differences in perceived health status according to the stage of exercise change. Also there were significant differences in the scores of ADL, depression, and life satisfaction according to the stage of exercise change. Conclusion: The tailored exercise seems to decrease depression while promoting physical health status and life satisfaction among the rural elderly. We suggest considering the client's intention and motivation when developing exercise programs.

• Restorative Dentistry and Endodontics
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• 제6권1호
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• pp.63-70
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• 1980

This study was to determine the incidence of pulp stone in each tooth by means of analyzing 375 orthopantomograph taken from 375 patients (252 male), 125 female). The pictures were grouped by age, 20s, 30s, 40s, 50s, and sex. The results were as follows 1. In the group of 20s, male showed the highest incidence in the first molar (40~50%) and the second highest was in the 2nd molar about 35%~50%. In the female group, the first molar and the second molar showed 25%~40%. 2. In the group of 30s, the highest value was found on the first molar and the next was the 2nd molar which appeared 30%~40% in male. In the female, the first molar was 55%~70% and the 2nd molar 30%~50% 3. In the group of 40s, the first molar represented highest value about 45%~60% and the 2nd molar was 40~60% in the male. Female group also showed in the first molar 30%~50% and the second molar 25~30%. 4. In the group of 50s, the highest incidence was 40%~60% on the first molar and next was 35%~50% on the second molar in male, in femalegroup showed 30%~50% on the first molar and 25%~50% on the second molar. 5. The incidence in upper was higher than that of lower. 6. Comparison between right and left showed right was slightly higher than left side.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2009년도 공동학술대회
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• pp.471-474
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• 2009

해양교통시설측정선 한빛호는 우리나라 영해에서 수신 가능한 해양교통시설 관련 신호에 대한 감시 및 평가를 수행한다. 그러나 GPS에 이어, GLONASS, QZSS, GALILEO 등 새로운 GNSS의 구축이 진행되고 있으며, 보정위성항법 역시 SBAS 보정서비스를 이용하는 것이 가능해졌다. 따라서 이렇게 급변하는 해양교통환경을 효과적으로 감시하고, 평가하기 위한 새로운 측정시스템이 필요하며, 본 논문에서는 이를 위한 한빛호 측정시스템 고도화 방안에 대해 제시한다.