DIFOTI 영상 최적화를 위한 광량에 대한 연구

김종빈,김종수,유승훈,김용기 大韓小兒齒科學會 2010 大韓小兒齒科學會誌 Vol.37 No.1

기존 DIFOTI 시스템의 문제점 중 디지털 영상 처리의 개선을 위하여 light emitting diode(LED)를 광원으로 사용하여 prototype DIFOTI 시스템을 개발하였다. 효율적이고 우수한 화질을 제공 할 수 있는 광량을 산출하기 위해 1일부터 20일까지 유치 법랑질을 Carbopol 907 인공 우식 용액을 사용하여 탈회시키고 실험 기간에 따른 법랑질 탈회 정도를 기존의 DIFOTI 시스템과 영상 분석을 통해 비교 평가하였으며, 탈회 정도에 대한 gold standard로 사용된 편광 현미경 소견과 비교하여 다음과 같은 결론을 얻었다. 1. 탈회 기간에 따라 두 시스템 모두 탈회 법랑질의 광도가 감소하는 양상을 보였다. 2. 정상 및 탈회 법랑질간의 광도의 차이는 DIFOTI 시스템이 prototype DIFOTI 시스템보다 더 큰 값을 보였다. 3. 편광현미경 관찰 소견과 비교해 볼 때, DIFOTI 시스템은 병소 깊이와 매우 유사한 변화 양상을 보여준 반면, prototype DIFOTI 시스템은 병소 깊이의 변화를 충분히 반영하지 못하였다. 보다 우수한 영상을 얻기 위해서는 광량의 최적화 과정과 함께 디지털 카메라의 조리개 조절도 병행되어야 할 것으로 판단되며, 이러한 단점은 소프트웨어적인 보완을 통해 개선될 수 있을 것으로 사료된다. This study was performed to compare the quality of image processing between the newly developed prototype using light emitting diode(LED) and the conventional DIFOTI system(EOS Inc., USA). To estimate the optimal light emitting power for the improved images, primary enamel surfaces treated under Carbopol 907 de-mineralizing solution were taken daily during 20 days of experimental periods by both DIFOTI systems. The results of comparative analyses on the images obtained from both systems with polarized image as gold standard can be summarized as follows: 1. Trans-illumination indices of images taken from primary enamel surfaces were decreased with time in both systems. 2. The differences of intensity of luminance between sound and de-mineralized enamel surface in prototype DIFOTI system was shown to be relatively smaller than conventional DIFOTI system. 3. From the comparative analysis of images from both DIFOTI system with polarized images as gold standard, the difference between sound and de-mineralized enamel surface of intensity of luminance of DIFOTI system was more correlated to polarized images than prototype of DIFOTI system. With the optimal LED emitting power, the control of aperture of digital camera is considered as the another key factor to improve the DIFOTI images. For the best image quality and analysis, the development of the improved image processing software is required.

Lip Bumper를 이용한 치료의 성공과 실패

김용기,김종수,김종빈,맹명호 大韓小兒齒科學會 1999 大韓小兒齒科學會誌 Vol.26 No.3

혼합치열기의 소아환자의 경미한 하악 전치부의 총생을 해결하는 문제와 하악 제 2 유구치의 조기 상실로 인한 하악 제 1 대구치의 근심경사 그리고 이에 따른 제 2 소구치의 맹출 공간 부족등을 해소하기 위한 여러가지의 방법들이 시도되어왔지만 저마다 그 술식의 적용범위나 방법 등에는 많은 어려움 들이 있어왔다. 이 연구의 목적은 이런 선택이 어려움을 가만하여 실제 임상에서 보다 간편하고 환자의 불편감을 줄여줄 수 있는 한 방법으로 Lip bumper를 이용한 술식을 소개하고 그 적용례를 통하여 성공과 실패 사례들을 소개함으로써 임상가들에게 보다 유익한 정보를 주기 위함이다. In the mixed dentition,many chidren have mild crowing of anterior dentition on the mandibular arch and mesial of mandibular molar.Lip bumper have been used to gain arch length for the alignment of mild to moderate crowded dental arches.As such,they may provide an alternative to extraction therapy.The claimed therapeutic effect of the lip bumper is bodily forward incisor movement,flaring of the low incisors,and distal tipping of the molar.The dental changes can be attributed to removal of lip pressure on the lower anterior dentition and the distal forces exerted at the molar at the abutment.The purpose of this study is to show more easily method of treatment for mild anterior crowding of mandible.

지혈적 치수 절단술의 효과에 관한 조직학적 연구

김종여,김종수,김용기,최장규 大韓小兒齒科學會 1998 大韓小兒齒科學會誌 Vol.25 No.1

The efficacy of several polpotomy methods were svaluated histologically on animal model using 6 beagles. At 1, 4, 6 weeks after pulpotomy, animals were sacreficed by perfusion method. Histomorphometric analysis was performed using computerized image analyzing system. Statistical comparisons were done using SPSS program. The following results were obtained: 1. Tissue responses after ferric sulfate treatment mainly consisted of fibrous ourface layer with the underneath pulpal tissue layer containing well-preserved odontoblasts. 2. Bleeding, fibrosis and necrosis are the main reactions obsereved in electrosurgical pulpotomy and the normal pulpal tissues were limited to the apical portion. 3. In the aspect of preserving the normal pulpal tissue, ferric sulfate pulpotomy was evaluated to be superior to formocresol or electrosurgical pulpotomy.

數種의 弗素製材에 의해 前處置 再植 齒牙의 祖織學的 反應에 關한 硏究

金鐘秀,金殷淑,金鐘好,金容琦 大韓小兒齒科學會 1997 大韓小兒齒科學會誌 Vol.24 No.2

The effect of fluoride pretreatment upon root resorption after delayed replantation was studied in beagle dogs. Upper and lower incisors were extracted and bench dried for 45minutes. 1% Stannous Fluoride solution, 2% neutral sodium fluoride gel and 1.23% acidulated phosphate fluoride gel were used for the pre-treatment of replanted root surface in the experimental groups. Replantation was done with no treatment in control group. After of an experimental periods 3 weeks, animals were sacrificed by perfusion followed by sample preparation. A histomorphometric method was applied for evaluation of tissue reactions observed in each group under light microscope. Scanning electron microscopic observation was done to find out any different surface topography between groups. The results were as follows: 1. Fluoride-treated groups showed in general the better healing patterns than untreated control group. 2. Comparisons between three experimental groups revealed the superiority of APF-treated group over the other groups in terms of tissue healing reaction by showing the highest frequency in uncomplicated healing pattern and surface resorption and the lowest in inflammatory resorption, but with no statistical significance(p>.05) 3. Scanning elecron micrographs showed the irregular distribution of resorption cavitie s and the attached bone of variable size and shape in all groups. 4. It can be conclued that the types of fluoride did not have significant impact on the early tissue reactions after delayed replantation under the condition of the present experiment.

내구성을 고려한 표면피복재의 성능평가에 관한 실험적 연구

김영덕,조봉석,윤종기,김용로,장종호,김무한 대한건축학회 2003 대한건축학회 학술발표대회 논문집 - 계획계/구조계 Vol.23 No.2

It is recognized that reinforcement corrosion is the main distress behind the present concern regarding concrete durability. The basic method to prevent reinforcement corrosion is coating the reinforcement concrete with surface coating materials but evaluating their performance is necessary to the work satisfactory because they have different performance for each other. In this study. to evaluate performance of surface coating materials, we compare their properties in terms of sticking strength and permeability of carbonation, chloride ion and water with actual reinforcement corrosion under environment of complex deterioration. The results showed that an increase in age also decreases Carbonation velocity coefficients, increases Chloride ion diffusion coefficients and increases water absorption coefficients. As well, an increase in age also increases corrosion of reinforcement due to permeability of carbonation and chloride ion. And sticking strength of inorganic coating material is higher than organic coating material.

遲延再植 時 齒根處理에 따른 齒周組織의 治癒에 關한 硏究

김종여,김종수,김용기,임성수 大韓小兒齒科學會 1998 大韓小兒齒科學會誌 Vol.25 No.1

The purpose of this study was to analyze comparatively the effect of various root pretreatments prior to delayed replantation. Total 6 beagle dogs were used for the experiment and 8 teeth per each animal were treated by several prepared regimens before replantation. After 3 & 6 weeks of experimental periods, animals were sacrificed by perfusion method. The results obtained form the present study can be summarized as follows: 1. All root pretreatment regimen used in this experiment showed effectiveness in the periodontal repair of delayed replanted teeth. 2. The teeth treated by the regimen of stannous fluoride combined with tetracycline revealed more favorable tissue response and less frepuent root resorption or ankylosis than other groups. 3. The long term effect of Group Ⅳ-regimen seems to be worth further study since the result at 6-weeks showed the significant progress in periodontal healing when compared to 3-week result which was not indicated in any other group.

한국 정신장애의 역학 조사 연구[I] : 각 정신장애의 유병률

조맹제,함봉진,김장규,박강규,정은기,서동우,김선욱,조성진,이준영,홍진표,최용성,박종익,이동우,이기철,배재남,신정호,정인원,박종한,배안,이충경 大韓神經精神醫學會 2004 신경정신의학 Vol.43 No.4

Objectives : This study aims to estimate the prevalence of the DSM-IV psychiatric disorders in Korean population using the Korean version of Composite International Diagnostic Interview (K-CIDI). Methods : Subjects were selected by taking multi-stage, cluster samples of 7,867 adult household residents, 18 to 64 years of age, in ten catchment areas. Total 78 trained interviewers administered the K-CIDI to the selected respondents, from June 1 to November30,2001. Results : Total 6,275 respondents completed the interview. Some 33.5% of respondents reported at least one lifetime disorder, 20.6% reported at least one-year disorder, and 16.7% reported at least one-month disorder. The most common lifetime disorders were alcohol abuse/dependence (17.24%), nicotine dependence/withdrawal (11.19%), specific phobia (5.16%), and major de-pressive disorder (4.25%). The lifetime prevalence of substance abuse/dependence (0.25%) and schizophrenia (0.16%) was very low. Nicotine and alcohol use disorder showed very high male/female ratio. Mood disorder and anxiety disorder were more prevalent among female than male. Conclusion : The prevalence of psychiatric disorders was high. In comparison with other studies, remarkable differences in distributions of psychiatric disorders across the areas and times were observed.

등고선 지도에서의 등고선 복원/인식에 관한 연구

金俊植,金基順,金海正 湖西大學校工業技術硏究所 1999 工業技術硏究所論文集 Vol.18 No.-

In this paper, we proposed the algorithm which extracts the contour lines in the contour map and reconstructs the broken ones. The contour lines is extracted by the algorithm using fairing method. Then the broken lines by symbols and the height number datum are reconstructed by using the Bezier polynomial function. In the reconstruction process, the control points which is searched by tracking the extracted contour lines are used. The reconstruction results is affected by the selection of the control points. The best selection is the choosing respectively the position of 6/10 between starting point and the cross point and between ending point and the cross one. The proposed algorithm has solved the problems with the conventional method by the division of the processing steps between the main contour lines and others. In the simulation results, the proposed method can be used in the digital elevation map generation. Also because the proposed one is consist of the automatic processing step, all the results can be obtained by the processing of computer.

탄산가스 레이저 조사가 법랑질 표면구조와 치면열구 전색재의 결합강도에 미치는 효과

김종수,김용기,윤동식 大韓小兒齒科學會 1998 大韓小兒齒科學會誌 Vol.25 No.4

In this study, sttempt has been made to evaluate the effect of CO₂laser irradiation on enamel surface structure and the bond strength of sealant material. Conventional acid etching was used as a control technic for comparison. The results obtained from this experiment were as follows: 1. The highest mean shear bond strength value was observed in samples of Group Ⅰ(acidetching) with the statistical significance(p<.05) between all the other groups. 2. The shear bond strength in Group Ⅳ was the lowest among laser etching groups. but there were no significant difference berween them(p>.05). 3. Scanning electron microscopic observation showed that the rough and irregular surface was created by CO₂laser treatment with the formation of numerous pores, micro-cuacks, and small bubble-like inclusion. Increasing the energy density induced localized surface melt with a thin smooth glaze-like appearance. 4. In acid-etched control stecimen cohesive failure predominated. whereas adhesive failure was the main mode in laser-treated group. Based upon the above-mentioned results, it can be assumed that the CO₂laser is not an adequate substitute for the acid-etch technique in enamel preconditioning. More studies are required to explore the effective condition of laser irradiation which could attain the better bond strength of restorative materials.

조건부가치평가법을 활용한 공공사업의 경제적 타당성 분석

김종대,조문기 한국환경경제학회 한국자원경제학회 2005 자원·환경경제연구 Vol.14 No.1

정부가 시행하는 환경정책등의 공공사업에 대한 경제적 타당성 분석은 그 성격이 영리 조직과는 질적으로 다르다. 공공사업의 경제적 타당성 분석에서 고려되어야 할 편익(benefit)으로는 계량적으로 측정할 수 있는 경제적 편익뿐만 아니라 시장에서 평가할 수 없는 공익적 편익까지도 고려되어야만 사업시행 여부에 대한 정확한 타당성 분석이 이루어질 수 있다. 그러나 시장가격이 존재하지 않는 공익적 편익의 추정은 매우 어렵다. 본 연구의 목적은 구미시의 하수관거정비 사업의 경제적 타당성 분석의 사례를 통해 보다 정확하고 엄밀한 타당성 분석 모델을 제시함에 있다. 이를 위해 시장에서 평가할 수 없는 환경보전이나 생활환경개선 등과 같은 공익적 편익을 경제학 분야에서 널리 이용되고 있는 조건부가치평가법(Contigent Valuation Method CVM)을 이용하여 추정하였다. 조건부가치평가법(CVM)에 의해 추정된 구미시 하수관거정비 사업에 대한 주민들의 가구당 월평균 지불의사액(willing-to-pay : WTP)은 2,865원으로 추정되었다. 추정된 생활환경개선 편익을 경제적 타당성 분석에 포함시켜 분석한 결과, 구미시 전체의 편익/비용 비율(B/C Ratio)은 0.97로 )보다 작은 것으로 나타났다. 본 연구는 조건부가치평가법(CVM)을 활용하여 공공사업에 대한 경제적 타당성 분석의 전형적인 모형을 처음으로 제시하였다는 점에서 향후 공공사업의 시행여부에 대한 정책적 의사결정과 학문발전에 크게 기여할 것으로 기대된다. Economic feasibility analysis for the public projects such as sewer improvement project differs from the one for the project by profit organization in that the former has to take into consideration the public benefit that cannot be priced in the market. This study presents a model case study for the economic feasibility analysis for the sewer improvement project by the City of Gumi, Korea. The project is planned for the period of 2003~2021. It utilized Contingent Valuation Method(CVM) to assess the public benefits such as improvement of environmental quality and quality of life that can not be priced in the market. WTP(Willing-to-pay) of a household of the Gumi was estimated at 2,865 Korean Won on average. The result of an economic feasibility test including the estimated WTP indicates that B/C ratio of the project turned out to be 0.97, slightly less than 1. This study is the first application of WTP estimated by CVM to the economic feasibility analysis of public project in Korea. It is expected to contribute to the decision makings in the public policy domain as well as academic development.