풍선 확장술을 이용한 소아 식도 협착의 치료

주성욱,이기재,김인원,김우선,연경모,박귀원,김우기,유필문,한만청 대한영상의학회 1992 대한영상의학회지 Vol.28 No.5

Balloon dilatation has been applied in treatint of various pathologic narrowing of the hollow viscus. It is now accepted as a very effective modality especially in treating esophageal stenosis obviating surgical procedure. We performed 128 ballon dilatations in 29 patients with the number of dilatations in each patient ranging from once to 12 times. The age distribution of the patients was from 3 weeks to 6 years, with the median age of 3 months. Twenty ninepatients consisted of 25 postoperative esophageal strictures (21 esophageal atresia with tracheoesophageal fistula, 1 congenital esophageal stenosis, 2 tracheobronchial remnant, and 1 congenital esophageal stenosis with esophageal atresia), 2 achalasia, 1 congenital esophageal stenosis, and 1 corrosive esophagitis. We had successful dilatation in 22 patients, who showed subsequent relief of symptoms and improvement in the diameter of stenotic segment. In 4 patients, esophageal perforation occured during the procedure, one r quiring emergency thoracotomy and the other threeconservative managment. Seven patients had no improvement in stenotic sites after several balloon dilatations. Failed cases were congenital stenosis, achalasia, corrosive esophagitis and four postoperative strictures. We believe that balloon dilatation is the procedure of choice in the treatment of postoperative esophageal stricture in infants and children and is a safe method as the perforation which can complicate the procedure could be managed conservatively.

초초임계압 발전용 소재의 장시간 열처리에 따른 미세조직 변화와 기계적 특성의 상관관계 연구

주성욱,유정훈,신기삼,허성강,이재현,석진익,김정태,김병훈,Joo Sungwook,Yoo Junghoon,Shin Keesam,Hur Sung Kang,Lee Je-Hyun,Suk Jin Ik,Kim Jeong Tae,Kim Byung Hoon 한국재료학회 2005 한국재료학회지 Vol.15 No.1

For the good combination of high-temperature strength, toughness and creep property, $9-12\%$ chromium steels are often used for gas turbine compressors, steam turbine rotors, blade and casing. In this study, the correlation of microstructural evolution and mechanical properties was investigated fur the specimens heat-treated at 600, 650 and $700^{\circ}C$ for 1000, 3000 and 5000 hrs. The microstructure of as-received specimen was tempered martensite with a high dislocation density, small sub-grains and fine secondary phase such as $M_23C_6$. Aging for long-time at high temperature caused the growth of martensite lath and the decrease of dislocation density resulting in the decrease in strength. However, the evolution of secondary phases had influence on hardness, yield strength and impact property. In the group A specimen aged at $600^{\circ}C\;and\;650^{\circ}C$, Laves phase was observed. The Laves phase caused the increase of the hardness and the decrease of the impact property. In addition, the abrupt growth of secondary phases caused decrease of the impact property in both A and B group specimens.

9-12%Cr강의 첨가원소 및 열처리에 따른 미세조직거동과 경도변화

주성욱,유정훈,신기삼,허성강,이재현,석진익,김병훈,김정태 국립7개대학공동논문집간행위원회 2004 공업기술연구 Vol.4 No.-

9-12%Cr steel are getting increasing attention for expanded application as high temperature materials applicable for gas turbine compressors, steam turbine rotors, blade and casing. For efficient and extensive application of 9-12%Cr steel, the data in addition to the improvement of mechanical properties on the correlation of microstructural evolution and mechanical properties are inevitable and thus the investigation in this study is performed for the determination for the specimens heat-treated at 600, 650 and 700℃ for 1000, 3000 and 5000hrs. The microstructure of as-received specimen was tempered martensite, with a high dislocation density and secondary phases. Upon high temperature heat-treatment, the martensite lath got larger and dislocation density decreased resulting the reduction of the strength. In addition, sharp growth of secondary phases was observed in the specimen heat-treated at 700℃ for 5000hrs. A specimen aged at 600℃ and 650℃ Laves phase was observed. The hardness showed close relationship with the secondary phase particle and dislocation density.

The Balloon Dilatation and Large Profile Catheter Maintenance Method for the Management of the Bile Duct Stricture Following Liver Transplantation

주성욱,신성욱,도영수,Wei Chiang Liu,박광보,Yon Mi Sung,주인욱 대한영상의학회 2006 Korean Journal of Radiology Vol.7 No.1

Objective: We wanted to evaluate the therapeutic efficacy of the percutaneous balloon dilatation and large profile catheter maintenance method for the management of patients with anastomotic biliary strictures following liver transplant. Materials and Methods: From May 1999 to June 2003, 12 patients with symptomatic benign biliary stricture complicated by liver transplantation were treated with the percutaneous balloon dilatation and large profile catheter maintenance method (1 6 months). The patients were eight males and four females, and their ages ranged from 20 to 62 years (mean age: 44 years). Ten patients underwent living donor liver transplantation and two underwent cadaveric liver transplantation. Postoperative biliary strictures occurred from two to 21 months (mean age: 18 months) after liver transplantation. Results: The initial technical success rate was 92%. Patency of the bile duct was preserved for eight to 40 months (mean period: 19 months) in 10 of 12 (84%) patients. When reviewing two patients (17%), secondary balloon dilatations were needed for treating the delayed recurrence of biliary stricture. In one patient, no recurrent stenosis was seen during the further 10 months follow-up after secondary balloon dilatation. Another patient did not response to secondary balloon dilatation, and he was treated by surgery. Eleven of 12 patients (92%) showed good biliary patency for 8 40 months (mean period: 19 months) of follow-up. Conclusion: The percutaneous balloon dilatation and large profile catheter maintenance method is an effective therapeutic alternative for the treatment of most biliary strictures that complicate liver transplantation. It has a high success rate and it should be considered before surgery.

고강도 강판의 스프링백 거동 연구

주성욱(S.W. Joo),이승욱(S.U. Lee),문지훈(J.H. Mun),백남종(N.J. Baek) 한국생산제조학회 2015 한국생산제조시스템학회 학술발표대회 논문집 Vol.2015 No.10

효율적인 NC 밀링 시뮬레이션을 위한 삼각형 메쉬 감소 알고리즘의 개발

주성욱(Sung-Wook Joo),이상헌(Sang Hun Lee),김현수(Hyun-Soo Kim),박기현(Kee Hyun Park) 한국정밀공학회 1999 한국정밀공학회 학술발표대회 논문집 Vol.1999 No.11월

실시간 3축 NC 밀링 시뮬레이션을 위한 메쉬 간략화 방법

주성욱(Joo, S. W.),이상헌(Lee, S. H.),박기현(Park, K. H.) (사)한국CDE학회 2000 한국CDE학회 논문집 Vol.5 No.4

Median Modified Wiener Filter for Noise Reduction in Computed Tomographic Image using Simulated Male Adult Human Phantom

주성욱(Sunguk Ju),안병헌(Byungheon An),강성현(Seong-Hyeon Kang),이영진(Youngjin Lee) 한국방사선학회 2021 한국방사선학회 논문지 Vol.15 No.1

전산화단층촬영장치 (computed tomography, CT)는 다른 방사선 촬영 장치와 비교하면 피폭이 많다는 문제점이 있다. 이러한 피폭을 감소하기 위하여 저선량 촬영을 하게 되면 영상에 잡음이 증가하게 된다. 이를 보완하기 위해 환자의 피폭선량은 감소시키면서 영상의 화질을 향상하는 다양한 잡음 제거 알고리즘이 개발되었으며, 그 중 우수한 시간 분해능을 가진 CT 장치에 효과적으로 적용할 수 있는 median modified Wie ner filter (MMWF) 알고리즘이 제시되었다. 본 연구의 목적은 MMWF 알고리즘의 마스크 크기를 최적화하고, 기존의 알고리즘들에 대한 MMWF 알고리즘의 잡음 제거의 우수성을 보는 것이다. MATLAB 프로그램을 이용하여 획득한 Gaussian 잡음이 부가된 MASH 팬텀 복부 영상들로부터 각각의 마스크 크기가 설정된 MMWF 알고리즘을 적용한 후 root mean square error (RMSE), peak signal-to-noise ratio (PSNR), coefficient co rrelation (CC) 그리고 universal image quality index (UQI) 값을 비교하였다. 그 결과 5 × 5 마스크 크기에서 RMSE 값이 가장 낮고, PSNR, CC, UQI 값이 가장 높았다는 것을 확인할 수 있었다. 또한, 최적화된 마스크 크기로 Gaussian 필터, median 필터, Wiener 필터에 대한 MMWF의 RMSE, PSNR, CC, UQI 값을 비교하였으며 그 결과 MMWF 알고리즘에서 가장 개선된 RMSE, PSNR, CC, UQI 값을 얻을 수 있었다. Computed tomography (CT) has the problem of having more radiation exposure compared to other radiographic apparatus. There is a low-dose imaging technique for reducing exposure, but it has a disadvantage of increasing noise in the image. To compensate for this, various noise reduction algorithms have been developed that improve image quality while reducing the exposure dose of patients, of which the median modified Wiener filter (MMWF) algorithm that can be effectively applied to CT devices with excellent time resolution has been presented. The purpose of this study is to optimize the mask size of MMWF algorithm and to see the excellence of noise reduction of MMWF algorithm for existing algorithms. After applying the MMWF algorithm with each mask sizes set from the MASH phantom abdominal images acquired using the MATLAB program, which includes Gaussian noise added, and compared the values of root mean square error (RMSE), peak signal-to-noise ratio (PSNR), coefficient correlation (CC), and universal image quality index (UQI). The results showed that RMSE value was the lowest and PSNR, CC and UQI values were the highest in the 5 x 5 mask size. In addition, comparing Gaussian filter, median filter, Wiener filter, and MMWF with RMSE, PSNR, CC, and UQI by applying the optimized mask size. As a result, the most improved RMSE, PSNR, CC, and UQI values were showed in MMWF algorithms.

Depth 정보를 이용한 CamShift 추적 알고리즘의 성능 개선

최한고,주성욱 한국융합신호처리학회 2017 융합신호처리학회 논문지 (JISPS) Vol.18 No.2

This study deals with a color-based tracking method of a moving object effectively in case that the color of the moving object is same as or similar to that of background. The CamShift algorithm, which is the representative color-based tracking method, shows unstable tracking when the color of moving objects exists in the background. In order to overcome the drawback, this paper proposes the CamShift algorithm merged with depth information of the object. Depth information can be obtained from Kinect device which measures the distance information of all pixels in an image. Experimental result shows that the proposed tracking method, the Camshift merged with depth information of the tracking object, makes up for the unstable tracking of the existing CamShift algorithm and also shows improved tracking performance in comparison with only CamShift algorithm. 본 연구에서는 이동 물체의 색상이 배경 내 색상과 동일하거나 유사한 색상이 존재하는 경우 컬러기반 에서 효과적으로 이동 물체의 추적 방법을 다루고 있다. 대표적인 컬러 기반 추적방법인 CamShift 알고리즘은 배경 영상에 이동물체의 색상이 존재하는 경우 불안정한 추적을 보여주고 있다. 이러한 단점을 극복하기 위해 본 논문에서는 물체의 Depth 정보를 병합한 CamShift 알고리즘을 제안하고 있다. Depth 정보 영상의 모든 픽셀의 거리정보를 측정하는 Kinect 장치로부터 구할 수 있다. 실험결과 이동물체의 거리정보를 병합시킨 제안 된 추적 방법은 기존 CamShift 알고리즘의 불안정한 추적기능을 보완하였고, CamShift 알고리즘만 사용한 경 우와 비교해 볼 때 추적성능을 향상시켰다.

IN 738LC 합금의 미세조직 열화와 물성의 상관성 연구

유정훈,주성욱,신기삼,허성강,이재현,김의현,정진성,장성호,송기욱,하정수,Yoo Junghoon,Jo Sungwook,Shin Keesam,Hur Sungkang,Lee Je-Hyun,Kim Eui-Hyun,Jung Jine-sung,Chang Sungho,Song Geewook,Ha Jeongsoo 한국재료학회 2004 한국재료학회지 Vol.14 No.1

IN 738LC, the major material for gas-turbine for power generation, was heat treated at $750^{\circ}C$, $850^{\circ}C$, $950^{\circ}C$ for 1000, 2000, and 4000 hrs and the microstructural evolution and mechanical properties were examined using optical microscope, XRD, SEM/EDS. The results showed ${\gamma}$', the main strengthening elements in this alloy, was about 300 nm in size and was about 56% by area fraction in as-cast samples. The area fraction of ${\gamma}$' peaked at 2000 hours at $750^{\circ}C$. The average diameter of the ${\gamma}$' which was about 300 nm at ascast specimen increased to about 1 $\mu\textrm{m}$ after heat treatment at $950^{\circ}C$ for 4000 hrs. Carbides were formed at dendrite, cell or grain boundaries which was ascribed to the segregation caused by solute redistribution during solidification. It was found that MC type carbides formed at low temperature, whereas carbides of $M_{23}$ /$C_{ 6}$/ type formed at higher temperature or at longer degradation. The hardness and impact energy decreased as the heat treatment temperature or time of retention increased, which was inaccrodance with the area fraction of ${\gamma}$'.