공간적 영상 분할에서 과분할 방지를 위한 개선된 분수령 알고리즘

윤영우,김상곤,전대성,장주석 영남대학교 공업기술연구소 2001 工業技術硏究所論文集 Vol.29 No.1

In this paper, we propose the improved watershed algorithm that resolves the oversegmentation problem shown in the previous watershed algorithm and its modifications when the spatial video segmentation is performed. The principal idea of the proposed algorithm is merging the shallow catchment basin whose depth is less than a given threshold into the deeper one during flooding step. In the flooding process, the growth of the existing catchment basins and the extraction of newly flooded ones are accomplished. We present the experimental results using several MPEG test sequences in the last part of the paper. As a consequence, the proposed algorithm shows good segmentation results according to the thresholds applied by adding very small amount of calculations.

교정력이 흰쥐의 치아이동량과 치근흡수에 미치는 영향

김일곤,김광원,윤영주 대한치과교정학회 1999 대한치과교정학회지 Vol.29 No.5

본 연구는 치아를 실험적으로 이동시킬 때, 교정력의 크기와 적용방법에 따른 치아이동 양상의 차이가 존재하는 지의 여부와 치근흡수와의 관련 여부에 대하여 평가하고자 하였다. 300g 전후의 건강한 수컷 흰쥐 24마리를 세 군으로 나누고 상악 제 1대구치와 상악중절치 사이에 NiTi closed coil spring을 장착하여, 각 군당 50g(A군), 100g(B군), 25g(C군)을 적용하였고 C군의 경우에는 교정력을 적용한 지 4일째 50g으로 힘을 증가하였다. 15일간 교정력을 적용하는 동안 매일 ehter로 흡입 마취를 시행하고 치아이동거리를 digital caliper로 측정하고 15일간의 실험기간 종료 후 상악 제1대구치 치근부의 조직표본을 제작하여 광학 현미경으로 관찰한 바 다음과 같은 결과를 얻었다. 1. 각 군별 15일간 총 치아이동거리는 B군에서 가장 컸고, 그 다음 C군, A군의 순이었으나 통계학적으로 유의성 있는 차이는 없었다. 2. A, B, C군 모두 전형적인 치아의 이동양상을 보여주었으며 치아이동 지체기가 끝난 날은 C, B, A군의 순서로 각각 7, 8, 9일째 끝났으나 통계학적으로 유의성있는 차이는 없었다. 3. A, B, C군 모두에서 치근의 흡수양사을 관찰할 수 있었고, 특히 B군에서 가장 심한 치근흡수양상을 보여주었고, C 군에서 치근흡수의 양상이 가장 적었다. 이상을 종합해볼 때, 교정력이 크다고 하여 더 바른 치아이동이 일어난다고 볼 수 없으며 교정력이 클수록 초자양변성대가 광범위하게 형성되어 오히려 치근의 흡수도 증가하므로 교정력을 적용할 때 초기 교정력을 보다 적게 적용하여 초자양변성대 형성범위를 줄인 뒤 교정력을 증가시키는 방법이 치근흡수를 최소화하면서 효과적인 치아이동을 얻을 수 있을 것으로 생각된다. This study was undertaken to investigate the relation between orthodontic force magnitude and the amount of tooth movement. And more light force application for reducing root resorption. Twenty-four rats were divided into three experimental groups(A,B,C) based on force magnitude and application method. Springs of 50g force were applied to A group, springs of 100g force were applied to B group and springs of 25g force were applied to C group initially, and after 4 days springs of C group were changed to springs of 50 force. Two kinds of sentalloy (GAC U.S.A) closed coil spring, 50g and 100g, were used. And we made 25g springs by heat treatment process of 50g springs. Each spring was inserted between the maxillary central incisor and the maxillary left first molar. Amounts of tooth movement were measured every day by digital caliper(Digimatic, Mitutoyo, Japan) under inhalation anesthesia for 15days. After 15days, all rats were sacrificed and histological samples were obtained with Hematoxyline-Eosin stain and Masson's trichrome stain. Following conclusion were made ; 1. Group B showed the mean cumulative tooth movement of 2.19±0.41㎜ at 15th day, which was greatest among three groups, followed by group C(2.06±0.10㎜), group A(1.90±0.49㎜) respectively. However, there was no statistically difference among three groups. 2. All groups showed general tooth movement pattern and A, B, C group finished lag phase at 9th, 8th, 7th day, but there was no statistical significance. 3. Group A, B, C showed root resorption and especially group B showed the most severe root resorption and group C showed milder root resorption than other groups. According to the above results, large initial force with the development of a fairly widespread hyalinized zone may cause severe root resorption, so initial force should be applied lightly to reduce hyalinized area and eventually root resorption and increased force will induce efficient tooth movement.

제습윤제의 적용이 상아질 접착에 미치는 효과

조영곤,박일윤,이영곤 大韓齒科保存學會 2003 Restorative Dentistry & Endodontics Vol.28 No.1

This study compared the dentin adhesion to composite resin according to air-dry. blot dry, application of rewetting agent on air-day or blot dry dentin surface by microleakag test and SEM observation. For microleakage test, class V cavity preparations with dential margins were prepared on both buccal and lingual surfaces of 40 extracted human molars. For SEM observation, occlusal dentin of 20 extracted human molars were exposed. After etched the dentin, prepared teeth were randomly divided into four groups; Dgroup: air dry for 10-15 sec., B group: blot dry with moist cotton pellet. D-R group: air dry and rewet with Aqua-Prep F for 20 sec., B-R group: blot dry and rewet with Aqua-Prep F for 20 sec. Treated cavities and surfaces were filled or constructed using One-Step adhesives and Aelitefil composite resins. Specimens were stored in distilled water for 24 hours. For microleakage test, the specimens were thermocycled and soaked into 2% methylene blue. The specimens were sectioned longitudinally and evaluated for microleakage under steromicroscope. The data were statistically analysed by Kruskal-Wallis Test. Mann-Whitney and Wilcoxon singed ranked tests. For SEM observation, the specimens were bisectioned mesiodiatally. After decalcified and deproteinized. specimens were observed uder SEM. The results of this study were as follows; 1. The microleakages on dentinal margin were the highest in D group compared with B group, D-R group, and B-R group(p<0.05). But there was no significant difference between B group, D-R group and B-R group. 2. D group showed gap and a few resin tags between dentin and composite resin. 3. B group, D-R group, and B-R groups showed close adaptation between dentin and composite resin, It showed that resin rags in B group were numerous and long, in D-R group were few and short, in B-R group were numerous and short or long. 4. Adhesive layer showed in D-R group (10㎛) and B-R group (3㎛)In conclusion, use of rewetting agent to dry dentin was efficient to dentin adhesion, also it did not provide reverse effect on blot dry dentin.

융기성 피부섬유육종 1예

강인경,윤영곤 朝鮮大學校 附設 醫學硏究所 1992 The Medical Journal of Chosun University Vol.17 No.1

Dermatofibrosarcoma protuberans(DFSP) is an uncommon tumor that arises in the dermis. It is characterized by slow invasive growth, frequent local recurrence after excision and infrequent metastasis. We report a case of DFSP who presented with an erythematous, firm nodule with satellite lesion on the left quadrant of the abdomen in a 52-year-old female. Histopathologically, this tumor showed a uniform cellular proliferation of fibroblast in a storiform or cartwheel pattern in the dermis and subcutis. The peripheral portions of the tumor may have a deceptively bland appearance, approaching that of normal collagen.

One-bottle 상아질 접착제의 전단결합강도와 접착성에 관한 부식시간의 효과

박광수,박일윤,조영곤 大韓齒科保存學會 1999 Restorative Dentistry & Endodontics Vol.24 No.1

광중합형과 자가중합형 글라스 아이오노머 시멘트의 변연 접합성에 관한 연구

허승면,조영곤,박일윤 大韓齒科保存學會 1994 Restorative Dentistry & Endodontics Vol.19 No.1

보-기둥 접합부의 이력거동을 고려한 RC 평면골조의 내진해석

조용부,김영곤,우종열,윤정배 慶尙大學校生産技術硏究所 1999 生産技術硏究所論文集 Vol.15 No.-

The analytical studies from the test results are presented. From experimental envelope curve, hysteretic behaviors under cyclic loading are modeled for beam-column subassemblages. Modelled curves show relatively good reproduction for experimental curves. Finally, seismic performances are investigated for 7 story plain framed structure by nonlinear dynamic analysis. The resulting responses are different by each beam-column joint design.

배달 미니 게임 개발:"최고의 웨이터를 꿈꾸며"

김정훈,정한교,김영옥,김중곤,박정윤,윤진성,김경식 호서대학교 반도체제조장비국산화연구센터 2001 반도체장비학술심포지움 Vol.2001 No.-

본 미니 게임은 웨이터라는 직업을 모티브로 하여서 남녀노소 누구나 재미를 느낌과 동시에 기억력 향상시켜 주는 게임제작이라는 목적아래 제작되었다.본 논문에서는 이 게임의 제작과정을 기술하고자 한다.이 게임은 제3회 AGC(한국 아마추어 게임제작 공모전)에서 우수 작으로 선정되었다.

화소 간축과 블록의 MAD를 이용한 고속 적응 블록 정합 기법

김준한,박준호,전대성,김상곤,윤영우 영남대학교 공업기술연구소 1999 工業技術硏究所論文集 Vol.27 No.2

We propose a fast block matching technique that adaptively limits searching depth using the value of MAD and the adjustment of the number of searching points by pixel decimation when estimating motions in the field of video compression. The underlying schemes of the proposed technique are the three step searching(TSS) scheme, pixel decimation, and the MAD as block matching criterion. In block matching schemes, the picture quality is proportional to the number of searching points that are used in estimating block motions. It also enhances the quality by increasing the points to be searched, because the probability of falling into the local minima can be decreased compared to the TSS scheme. The increasing computational complexity, proportional to the increased searching points, is reduced by introducing the pixel decimation method. Moreover, we can reduce the amount of computation by determining the search depth using the block MAD. With the proposed algorithm, we performed a lot of simulation for the various MPEG video data. As a consequence, it can improve the picture quality while reducing the amount of computation involved comparing to the TSS scheme.

백내장 수술환자 진료결과들간의 관계 : 사전 연구를 중심으로 Pilot study

박은철,김한중,홍영재,조우현,손명세,임승정,강형곤,최윤정 한국의료QA학회 1998 한국의료질향상학회지 Vol.5 No.1

Background : This study was done to assess the relationship among multiple patient outcomes of cataract surgery perioperatively, 3-4 months and 12 months after surgery. The patient outcomes include changes in visual acuity(operated eye, better eye), visual function(VF-14), patient satisfaction, subjective satisfaction with vision, and subjective overall health status. Methods : For the assessment of relationship, prospective study was performed with 92 patients who had undergone either one or both eye cataract surgery by 3 ophthalmologists practicing at a university hospital. Patients were interviewed, and clinical data were obtained. Doctors were questioned with self-entered questionnaire forms. Medical record was examined to understand surgery process. The survey was conducted at 4 stages : preoperatively, perioperatively, postoperative 3-4 months, and postoperative 12 months. Results : The correlations within patient outcomes at 4 stages - the visual acuity of operated eye and that of better eye, patient satisfaction and VF-14, subjective overall health status and relative health status as against others - were found to be positively correlated. The change in the visual acuity of operated eye and better eye was correlated with VF-14 as well as with patient satisfaction. The change was also correlated with overall health status. However, the correlations between variables were decreased as the postoperative period got longer. Conclusion : As for the postoperative clinical patient outcomes, VF-14 is acted to linker between visual acuity - clinical outcomes and overall health status - endpoint outcomes. Therefore, VF-14 is the index of patient-sided and disease-specific outcome for cataract surgery.