상장간동맥 색전증 2예

최경현,서재관,안병권 대한혈관외과학회 1988 Vascular Specialist International Vol.4 No.1

The superior mesenteric artery embolism is a rare disease, and diagnosis and treatment were delayed. The mortality was very high. In recent years, the mortality has decreased gradually because of the development of vascular surgery including angiography, fogarty catheter etc. There were a few cases reports in korean literature. We experienced two cases of superior mesenteric artery embolism in recent years: one case was successfully treated with the embolectomy and distal thrombectomy of the necrotized jejunum and segmental resection of the necrotized jejunum, and at next day, the necrotized jejunum was resected in second look operation, another was also treated with the embolectomy of abdominal aorta and superior mesenteric artery and the resection of the necrotized intestine, but died. These cases had no abnormality in EKG, echocardiography and upper aorta on angiography, and no evidence of cardiac disease clinically. There were thrombocytosis as well as leukocytosis. The sigmificance of thrombocytosis in arterial embolization is not certain now. Subsequent bone marrow aspiration in the living case did'nt show abnormality.

감성공학적인 접근법을 이용한 그래픽 주행 시뮬레이션 개발

최경현 濟州大學校 産業技術硏究所 2000 산업기술연구소논문집 Vol.11 No.1

This research focuses on the evaluation of the perceived velocity in a graphic environment. The investigation of virtual driving reveals that the perceived velocity is closely related to the virtual environment. Especially. the major two factors are distance between the virtual driver and the array of environmental objects and the repetition pattern i.e.. density of environmental objects. Experiments were carried out to acquire a relationship between the perceived velocity and each factor. A graphical representation of a vehicle and its surrounding environment have been constructed by three-dimensional tools, Pro/ENGINEER and dVISE. Based on the experimental results, nonlinear regression equations are derived for the relationships between the perceived velocity and distanceldensity.

엑시머 레이저를 이용한 3차원 마이크로 가공

최경현 제주대학교 공과대학 첨단기술연구소 2001 尖端技術硏究所論文集 Vol.12 No.2

A new 3D micromachining method, called Hole Area Modulation(HAM), has been introduced to enhance the current micromachining technology. In this method, information on the depth of machining is converted to the sizes of small holes in the mask. The machining is carried out with a simple 2D movement of the workpiece. This method can be applied for machining various kinds of microcavities in various materials. In this paper, the mathematical model for excimer laser micromachining based on HAM and the determination of the optimal laser ablation conditions(width, hole radius, step size, path etc.) is suggested completed by employing using Genetic Algorithm(GA).

항문 주위 피부로 전이한 위암 1례

최경현,윤기영,이상호 고신대학교의과대학 2007 고신대학교 의과대학 학술지 Vol.22 No.2

Gastric adenocarcinoma can metastasize to various organ sites such as regional and distant lymph node(s), peritoneum, liver, ovary, lung, brain, bone, adrenal gland, skin and other sites via lymphatics and blood flow, or by direct seeding. But isolated perianal metastasis without other skin area involvement was rare and we could not find in the literature survey. So we are going to report this case; Patient was 48 year-old male with Borrmann type III adenocarcinoma(tubular poor type) located lesser curvature side of the Upper and Middle stomach invaded to underlying pancreas. He received total gastrectomy and Roux en Y gastrojejunostomy, distal pancreatectomy and splenctomy at Feb 26th 1999. Four out of 33 regional nodes were metastatic. He recovered farely well after operation and resumed work as full time farmer until Jul 11th 2003 follow up exams when he was diagnosed as multiple liver metastases. Tumor markers was as follow; CEA 5.2 ng/ml(he smokes a pack per day), CA 19-9 11.5 U/ml and urine pepsinogen 30.6 ng/ml(the pre-hepatic recurrence level was 8.1 ng/ml). He received 7 cycles of taxotere and cisplatin intravenous chemotherapy with complete remission on CT scan at Nov 18th 2003. Then he developed a metastatic perianal adenocarcinoma at May 4th 2004. It did not respond to radiation therapy. So it was completely resected out with two resection procedures and an end type sigmoid colostomy for fecal diversion. There are no recurrence until Jul 24th 2007 when he received IM injection of vitamin B12 and follow up exams. The tumor markers was normal limit including urine pepsinogen 11 g/ml. With this experience, all patients should be carefully followed up after gastric cancer operation for recurrence. Urine pepsinogen level can be a useful tumor marker after total gastrectomy for gastric adenocarcinoma. Don't give up patient with recurrences before various efforts to eradicate it.

수직형 머시닝센타 이송시 스틱-슬립에 관한 연구

최경현,조규재,박종남,이승철 朝鮮大學校 機械技術硏究所 2004 機械技術硏究 Vol.7 No.2

볼나사 미끄럼 시스템에서 고속과 고정밀도를 이루는데 중대한 문제들은 마찰과 각 구성 요소들 사이에서의 마찰과 축 방향의 강성이 감소하여 나타난다 특히, 안내면에서의 마찰은 이송정밀도를 떨어뜨리는 좋지 않은 영향을 준다. 더욱이 스틱-슬립현상과 같은 특수한 마찰 형태는 미끄럼 시스템의 저 강성에서 일어난다. 스틱-슬립은 정밀도에 나쁜 영향을 가진다. 본 논문에서는 미끄럼 시스템의 정밀도에 있어서 스틱-슬립 마찰에 의한 운동오차에 따른 변화들을 고찰하여 이송정밀도의 해결 방안을 제시하려 하였다. In the ball screw slide system the major problems in accomplishing the high-speed and high-precision are the friction between elements and the decrease of axial stiffness. Especially the friction on the guide have a bad effect on the precision of sliding. Furthermore stick-slip occur when the low stiffness of slide system. The stick-slip have a bad influence on the precision. In this research, the affection of stick-slip friction to the precision of the slide system is studied and the possible solution of the precision is proposed.

하이브리드 ? 플로워 제어를 위한 오퍼레이션 모델에 관한 연구

최경현,배창현 濟州大學校 産業技術硏究所 2000 산업기술연구소논문집 Vol.11 No.1

Manufacturing system is composed of many activities that can be monitored and controlled at different level. A shop floor can be considered as an important level to develop Computer Integrated Manufacturing(CIM). However. a shop floor is the dynamic environment where the unexpected events continuously occur. and impose changes to planned activities. In this paper. task-oriented control model. called (MuLOM(Multi-Layered Operation Model), is suggested to represent control model for a hybrid control architecture which is composed three levels. i.e.. shop floor controller(SFC). intelligent agent controller( IAC) and equipment controller( EC).

멀티 에이전트 기반 샾 플로워 제어 시스템

최경현,조수정 朝鮮大學校 機械技術硏究所 2006 機械技術硏究 Vol.9 No.1

This paper addresses an intelligent agent-based shop floor control system for Flexible Manufacturing System(FMS). With an intelligent agent approach, the FMS will be achieve a adaptability to change of manufacturing environment. As the development methodology of shop floor control system, an object-oriented modeling technique is employed for building models associated with FMS operation. The active agent is contributed to control components of FMS in real-time, whereas the coordinator agent has great role. It communicates with other active agents to get information about status on system and generates the next optimal task through the making-decision logic and dispatch it to other active agent.

웹사이트 소개 : 최적화 소프트웨어의 벤치마킹 사이트

최경현 대한산업공학회 2002 ie 매거진 Vol.9 No.2

제32차 학술대회 : 81. 담낭 및 담도의 초음파 조영술

최경현,박영훈 () 대한외과학회 1980 대한외과학회 학술대회자료집 Vol.- No.-

Meniscus Height as a Function of Dimensionless Variables for Drop-on-demand Applications

최경현,Syed Murtuza Mehdi 한국물리학회 2013 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.62 No.9

This paper reports experimental correlations for the dimensionless meniscus height (h/D) as a function of the dimensionless variables that govern the physics of meniscus generation for dropon-demand applications. Two liquids were considered in this study: namely, ethylene glycol and ethanol. These liquids were selected because of their wide applicability in drop-on-demand applications. The dimensionless governing variables were found by performing a dimensional analysis of the system under consideration. The dimensionless meniscus height (h/D) was found to depend on two dimensionless numbers: the S number (S = σ/ρD2g) and the P number (P = pabs/ρDg). The behaviors of h/D for both the liquids were found to increase with increasing variables of interest and are discussed in terms of correlations.