Incisional Hernia in Adult Liver Transplant Recipients

( Ji Soo Lee ),( Kyeong Sik Kim ),( Chan Woo Cho ),( Kyo Won Lee ),( Gyu-seoung Choi ),( Jong Man Kim ),( Choon Hyuck David Kwon ),( Jae-won Joh ) 대한간학회 2017 춘·추계 학술대회 (KASL) Vol.2017 No.1

Aims: Incisional hernia is one of the complication following abdominal operation. Patients undergoing liver transplantation have a high risk of developing an incisional hernia because of immunosuppression. The purpose of this study is to review incisional hernia cases after liver transplantation and to identify the risk factors for hernia formation. Methods: We retrospectively reviewed and analyzed the medical records of the ninety-four incisional hernia patients after liver transplant recipients from January 2000 to December 2015 in single center institution. Results: 1463 underwent adult liver transplantation during the study period. 94 Incisional hernia patients were found among them. The overall incisional hernia rate was 6.4 %. Mean age was 54 years old and 76.6 % were men. No significant difference was observed for sex, diagnosis, smoking, alcohol, albumin, Child-Pugh score, MELD score, intensive care unit stay, hepatorenal syndrome, ventilator, spontaneous bacterial peritonitis, diabetes, bile leakage, wound problems between patients with incisional hernia and patients without incisional hernia. The characteristics of patients with incisional hernia showed old recipient, more body weight, higher body mass index, living donor recipient compared with patients without incisional hernia. Hypertension, tuberculosis, rejection, postoperative complication event before hernia were significant risk factor (p<0.05). Conclusions: Present study identifies the risk factors for incisional hernia. Surgeons should strive to reduce the risk of incisional hernia after adult liver transplantation.

무누액 배터리기판 격자의 전단공정 개발

이춘만,김대성,정종윤,조형찬 한국공작기계학회 2004 한국공작기계학회 추계학술대회논문집 Vol.2004 No.-

This study has been focused on the development of shear forming process of grid for lead-acid battery. The grid plays an important role in the flow of electricity because the grid is a skeleton of the pasted plate. Therefore, it must be of the highest quality to prevent plate failures and then, battery failure, and ensure the best battery performance possible. The finite element analysis of the shear forming process is carried out and the result is compared with the experimental data. The influence of the numerical parameters such as clearance, velocity of punch and critical damage value on the simulation results turns out to be very considerable.

축대칭 전기업셋단조 공정의 유한요소해석

이춘만 國立 昌原大學校 産業技術硏究所 1994 産技硏論文集 Vol.8 No.-

A thermo-viscoplastic finite element analysis is made for axisymmetric electro-upsetting process which is used for production of preforms of engine valves, flanged shaft and so on. The analysis of deformation and heat transfer are carried out for the process by decoupling the two analysis. An automatic remeshing technique is proposed by employing specially designed mesh structure. Process parameters, such as, heart transfer coefficient, upsetting temperature, heating current, feedrate of billet bar are discussed to obtain properly deformed shape.

타워식 자동 공구 교환장치의 성능 평가

이춘만,노영화,박동근 한국공작기계학회 2006 한국공작기계학회 추계학술대회논문집 Vol.2006 No.-

This study is concerned about the development and performance evaluation of a tower type ATC(Automatic Tool Changer). Recently, many studies have been undergoing to reduce working time in field of machine center. Tower type ATC have been developed to reduce the stand-by time by shortening tool exchanging time. The developed system can store more number of tools in small space. In order to evaluate the performance of tower type ATC, feeding speed and noise are measured by a laser interferometer and a noise level meter.

볼 나사의 BCD 정밀 측정기 개발에 관한 연구

이춘만,임상헌 국립7개대학공동논문집간행위원회 2004 공업기술연구 Vol.4 No.-

Amongst mechanical elements, a ball screw is the most important for feeding system. The ball screw requires high precision during machining process because a machine tool demands high accuracy. The high quality ball screw can be obtained by sustaining the lead accuracy, pre-load torque, and constant ball screw center diameter (BCD), etc. In this study, we are focused on the measurement of BCD and development of precision measuring instruments for the evaluation high quality ball screw. Finally, we can control the quality of a ball screw through the measurement of BCD.

레이저 절단기의 구조해석 및 모드해석

이춘만,임상헌 國立 昌原大學校 産業技術硏究所 2002 産技硏論文集 Vol.16 No.-

A laser cutting M/C is designed for the precise fabrications in the machine recently. The cutter is a gantry type one with specified functions of movability and strength in order to satisfy the workability. The gantry frame should move with a certain velocity in a relatively short time for the proper cutting of the object materials. The gantry is fitted with rank and pinion and the acceleration field is formed by actuating this rack and pinion. The relative displacement should be within the allowable design criteria to make sure the precise cutting of the materials by the laser. In this paper, modal and structural analysis for a laser cutter which is commonly used in the fabrication of machine, is carried out to check the design criteria of the system. The system is modeled by placing the proper shell and solid finite elements and fictitious mass properties to represent the real one.

곡선을 포함한 임의형상의 최적자동배치에 관한 연구

이춘만,백창현 國立 昌原大學校 産業技術硏究所 1998 産技硏論文集 Vol.12 No.-

Nesting is a difficult problem which is frequently encountered in a number of industries where raw material has to be cut enconomically from a given stock part. The problem is present in industerial applications like shipbuilding, parts of a machine, clothing, manufacturing, paper or leather cutting. An algorithm for automatic nesting is proposed to obtain optimal allocation on a given part. The goal is to cut the part out of the material in such a way as to minimize the waste. Some typical nesting problems are simulated by the developed program.

센서응용을 이한 CMOS열전대의 공정기술 개발

이광만,김진섭,이춘흥,Liu, C.C. 경북대학교 센서기술연구소 1995 연차보고서 Vol.1995 No.-

마이크로 열전센서는 마이크로히터와 열전소자로 구성된다. 열전도율이 낮고 내부응력이 최소화된 NON절연막 다이아프램을 LPCVD법, APCVD법 및 실리콘 이방성식각법을 각각 활용하여 형성하였다. Si_3N_4 및 SiO_2의 두께가 각각 1500Å 및 3000Å의 조합인 NON막이 가장 양호한 응력특성을 나타내었다. 고주파 스퍼터링법으로 형성된 백금박막을 이용한 히터와 온도감지기로 형성된 마이크로 가스유량센서를 제조하고 그 동작특성을 측정하였다. 유량센서의 동작특성은 100∼500sccm의 유량범위에서 양호한 선형성을 보였다. CMOS공정기술과 호환성을 갖는 마이크로 유량센서의 마스크패턴과 공정을 각각 설계하였다. A micro thermosensor is composed of a microheater and a thermo element. NON insulator diaphragm with low thermal conductivity and minimum internal stress was fabricated^by using LPCVD, APCVD and silicon anisotropic etch techniques. The deposited NON film represented the best stress characteristics when the thickness of Si_3N_4 and SiO_2 are 1500Å and 3000Å, respectively. A micro gas-flow sensor was fabricated and characterized that is consist of platinum thin film heater and temperature detector. The performance characteristics of the micro gas-flow sensor shows a good linearity within 100-500sccm flow rate range. Mask pattern and CMOS process of micro gas-flow sensor have been designed according to CMOS process technology.

트레이 자동 투입기 설계 및 개발에 관한 연구

이춘만,신성우 국립7개대학공동논문집간행위원회 2005 공업기술연구 Vol.5 No.-

A tray inserting machine is developed for automation of inserting plastic mold tray into a cardboard box. Plastic mold tray is used for protecting breakage of glass bottles. In this paper, two types of processes to divide the plastic mold tray are proposed. As a result, adhesion method by vacuum pad is accepted. And, static and modal analysis for the machine are also carried out to check the machine design using the commercial software, CATIA V5.

MQL 선삭가공시 가공조건의 표면거칠기 영향 분석

이춘만,황영국,정종윤 한국공작기계학회 2004 한국공작기계학회 추계학술대회논문집 Vol.2004 No.-

At present, industry and researchers are looking for ways to reduce the use of lubricants because of ecological and economical reasons. Therefore, metal cutting is to move toward dry cutting or semi-dry cutting. This paper presents an investigation into MQL(Minimum Quantity Lubrication) machining with the objective of deriving the optimum cutting conditions for the turning process of SM45C. To reach these goals several finish turning experiments were carried out, varying cutting speed, feed rate and oil quantity, with MQL. The surface roughness results of tests were measured and the effects of cutting conditions were analyzed by the method of Analysis of Variance(ANOVA). From the experimental results and ANOVA, it is found that a better surface roughness can be obtained by decreasing oil quantity and feed rate.