3원호 미끄럼 베어링을 적용한 공작기계 주축계의 정적 및 동적 특성 해석시스템 개발

조재완,김석일,이군석,김춘배 韓國工作機械學會 2000 한국생산제조학회지 Vol.9 No.4

In this study, a static and dynamic characteristics analysis system for machine tool spindle systems with 3 lobe sliding bearings is developed based on Timoshenko theory, finite element method and windows programming techniques. And the characteristic values of 3 lobe sliding bearings such as eccentricity ratio, attitude angle, friction coefficient, stiffness coefficients, damping coefficients and so on, are determined by using the thermal equilibrium condition of spindle sys-tems. Since the developed system has various analysis modules related to static deformation analysis, modal analysis, fre-quency response analysis and so on, it can be utilized to perform systematically the design and evaluation processes of spindle systems with 3 lobe sliding bearings under windows GUI environment.

크랭크샤프트의 기상 계측 시스템 개발

조현용,이원재,조재완,김석일 한국공작기계학회 2008 한국공작기계학회 추계학술대회논문집 Vol.2008 No.-

On-machine measurement (OMM) is considered as an effective approach to increase productivity in small batch production. This paper presents a specialized OMM system based on a touch probe, which can be used to measure and estimate the accuracies of crankshaft machined by a 5-axis multitasking machines. Measurement paths were created based on the CAD model of crankshaft and probe radius compensation, and were verified by virtual measurements. An NC program was created by performing the postprocessing of measurement paths, and was transferred to the multitasking machine, directly via RS232C interface. And the accuracies of crankshaft were measured through the touch probe controlled by the NC program. Especially, this specialized OMM system is more effective in case of measuring a large crankshaft because of handling difficulty due to its huge size and heavy weight.

내장형 모터와 리니어 모터를 적용한 초고속 수평형 머시닝센터의 열 특성 해석

김석일,조재완 한국공작기계학회 2004 한국공작기계학회 춘계학술대회논문집 Vol.2004 No.-

This paper presents the thermal characteristic analysis of a high-speed horizontal machining center with spindle speed of 50,000rpm and feedrate of 120m/min. The spindle system is designed based on the built-in motor, angular contact ceramic ball bearings, oil-air lubrication and oil-jacket cooling method. The X-axis and Y-axis feeding systems are composed of the linear motors and linear motion guides, and the Z-axis feeding system is composed of the servo-motor, ball screw and linear motion guides. The thermal characteristics such as the temperature distribution, temperature rise, thermal deformation and step response, are estimated based on the finite element model of machining center and the heat generation rates of heat sources related to the machine operation conditions. Especially, the thermal time constant assessed from the step response function is introduced as an index of thermal response characteristics.

내장형 모터와 리니어 모터를 적용한 초고속 수평형 머시닝센터의 열 특성 해석

김석일,조재완 한국공작기계학회 2004 한국생산제조학회지 Vol.13 No.5

This paper presents the thermal characteristic analysis of a high-speed horizontal machining center with spindle speed of 50,000rpm and feedrate of 120m/min. The spindle system is designed based on the built-in motor, angular contact ceramic ball bearings, oil-air lubrication and oil jacket cooling method. The X-axis and Y-axis feeding systems are composed of the linear motors and linear motion guides, and the Z-axis feeding system is composed of the servo-motor, ball screw and linear motion guides. The thermal characteristics such as the temperature distribution, temperature rise, thermal deformation and step response, are estimated based on the finite element model of machining center and the heat generation rates of heat sources related to the machine operation conditions. Especially, the thermal time constant assessed from the step response function is introduced as an index of thermal response characteristics.

내장형 모터와 리니어 모터를 적용한 초고속 수평형 머시닝센터의 구조 특성 해석

김석일,조재완 한국공작기계학회 2004 한국공작기계학회 추계학술대회논문집 Vol.2004 No.-

This paper presents the structural characteristics analysis of a high-speed horizontal machining center with spindle speed of 50,000rpm and feedrate of 120m/min. The spindle system is designed based on the built-in motor, angular contact ceramic ball bearings, oil-air lubrication and oil jacket cooling method. The X-axis and Y-axis feeding systems are composed of the linear motor and linear motion guides, and the Z-axis feeding system is composed of the servo-motor, ball screw and linear motion guide. The structural analysis model of the high-speed horizontal machining center is constructed by the finite element method, and the validity of structural design is estimated based on the structural deformation of the high-speed horizontal machining center and spindle nose caused by the gravity and inertia forces.

급성 백혈병 환자에서 수두양 피부병변을 보인 파종성 Fusarium 감염 1예와 국내 파종성 Fusarium 감염증에 대한 고찰

오수진,정희선,김준성,김태석,조병식,최수미,김명신,이연수,이석,신완식 대한감염학회 2007 감염과 화학요법 Vol.39 No.5

최근 면역저하환자의 증가와 함에 국내에서도 점차 침습성, 파종성 Fusarium 감염증 보고가 증가하고 있다. Fusarium 감염은 아스페르길루스 감염과 유사한 임상양상을 보이지만 특징적인 피부병변을 동반하고 혈액배양에서 균이 분리되는 경우가 더 많다. 저자들은 급성 림프구성 백혈병으로 진단받고 치료중인 30세 남자 환자에서 중증의 호중구 감소 상태에서 비특이적인 피부병변을 동반한 파종성 Fusarium 혈류감염을 경험하였기에 국내 증례 고찰과 함께 보고하는 바이다. 환자의 초기 피부병변은 구진에서 시작하여 주로 소포성 병변과 일부 통증을 동반한 결절 등 여러 형태로 나타났고, Tzank 도말검사 양성으로 비정형 수두로 오인되었다. 이후 피부병변은 농포로 변하였고, 혈액배양 및 피부 조직검사에서 파종성 Fusarium 감염으로 진단받았다. 환자는 liposomal amphotericin B, voriconazole 병합요법과 G-CSF 투여, 과립구 수혈을 받았으나, 호중구 감소증에서 회복하지 못하고 급성 호흡곤란증후군과 다장기 기능부전으로 사망하였다. 본 증례는 파종성 Fusarium 감염의 경우에도 수두양 병변으로 비특이적인 양상으로 나타날 수 있으므로, 감별진단을 위해 적극적으로 혈액배양과 피부조직검사를 시행해야 함을 보여준다. Recently, we experienced a case of disseminated fusarial blood stream infection with varicelloid skin eruptions, who had suffered from persistent neutropenic fever after salvage chemotherapy for relapsed acute lymphocytic leukemia (ALL). Neutropenia continued in spite of G-CSF and granulocyte transfusion, and he failed to respond to conventional amphotericin B initially, and then liposomal amphotericin B and voriconazole combination therapy. Disseminated fusariosis can be diagnosed by blood cultures in 50% of patients and present skin lesions in more than 80% of patients. So, typical skin lesions are important clue to diagnose of the disseminated fusariosis. However, many skin lesions in immunocompromised hosts are due to various infectious and non-infectious causes. So, this case shows that it is important to obtain biopsy specimens of skin lesions for histopathologic examination, culture and staining. Here, we present our case with the review of the literatures reported in our country, so far.

A Case of Pneumatosis Cystoides Intestinalis in an Allogenic Stem Cell Transplant Recipient Who had Bronchiolitis Obliterans and Pulmonary Infection by Mtcobacterium abscessus

김윤정,전은경,조병식,최수미,이석,민창기,신완식 대한감염학회 2008 감염과 화학요법 Vol.40 No.5

Hematopoietic stem cell transplantation (HSCT) can cause various complications involving lung, liver intestine and other organs, Chemotherapy, radiation therapy, and graft-versus-host disease (GVHD) may injure the cells in the intestinal mucosa of HSCT recipients. Pneumatosis cystoides intestinalis (PI) is a condition that presence of air in the bowel wall is demonstrated by radiologic or pathologic tests, It is one of the infrequent complications after HSCT and is associated with several medical and surgical conditions. However its pathogenesis and definite etiologic factors are still unknown. Here, we present a case of PI in a HSCT recipient, who was diagnosed of bronchiolitis obliterance accompanied with chronic GVHD and pulmonary disease caused by Mycobacterium abscessus.

바터 팽대부에 생긴 유암종 1예

강명주,지삼룡,박석주,이재익,조영완,김준영,박성재,박은택,이연재,이상혁,설상영,배상균 인제대학교 2006 仁濟醫學 Vol.27 No.-

Carcinoid tumors have been reported in a wide range of organs but most commonly involve the lungs, bronchi and gastrointestinal tract. Within the gastrointestinal tract, appendix is the most common location for carcinoid, followed by the distal small intestine, the rectum, and the stomach. Among these, primary involvement of the ampulla of Vater is extremely rare. We report a case of carcinoid tumor of ampulla of Vater. A 62-year-old man presented with epigastric soreness. Gastroduodenal endoscopy showed hyperemic bulging mass on ampulla of Vater and diagnosed as carcinoid tumor by histologic finding, with immunohistochemical study. In ^(111)In-octreoscan, tumor had regional lymph node metastasis, but no evidence of distant metastasis. Pancreatoduodenectomy with lymph node dissection was performed.

The Syndrome of Inappropriate Antidiuretic Hormone Secretion (SIADH) in a Patient with Systemic Lupus Erythematosus (SLE): A Case Report

( Min Seok Cho ),( Dae Hyun Kim ),( Woo Kyun Bae ),( Youn Kyoung Lee ),( Seong Kwon Ma ),( Shin Seok Lee ),( Soo Wan Kim ),( Nam Ho Kim ),( Ki Chul Choi ) 대한신장학회 2004 춘계학술대회 초록집 Vol.24 No.1

저 악성도 중심성 연골육종의 광범위 소파술 후 종양학적 및 기능적 예후

조완형(Wan-Hyeong Cho),이수용(Soo-Yong Lee),송원석(Won-Seok Song),공창배(Chang-Bae Kong),조상현(Sang-Hyun Cho),전대근(Dae-Geun Jeon) 대한정형외과학회 2011 대한정형외과학회지 Vol.46 No.5

목적: 저 악성도 중심성 연골육종의 치료방법 중 광범위 소파술 후 종양학적 및 기능적 결과에 대하여 알아보고자 하였다. 대상 및 방법: Grade Ⅰ으로 진단되어 광범위 소파술을 시행하고 보조 요법으로 과산화수소에 의한 화학적 소작술을 시행한 후 24개월 이상 추시가 가능하였던 160명의 연골육종 환자를 대상으로 하여 환자의 특성 및 국소 재발 및 원격 전이, 술후 기능 평가를 시행하였다. 결과: 5년 무병 생존율을 87.5%였다. 평균 추시 기간은 82.7개월이었으며 최종 추시까지 질환으로 인한 사망은 없었다. 술후 16명 환자의 평균 MSTS는 27.5(91.6%)로 측정되었다. 결론: 저 악성도 중심성 연골육성의 치료에 있어서 철저한 광범위 소파술과 보조요법을 병행하는 것은 광범위 절제술에 비하여 생존율에 영향을 주지 않으면서 광범위 절제술로 인한 합병증과 기능 소실을 피할 수 있는 방법이라 판단된다. Purpose: We analyzed the oncological and functional outcome of extended curettage for low-grade central chondrosarcoma Materials and Methods: We retrospectively reviewed 16 patients with Grade I central chondrosarcomas treated with extended curettage and adjuvant therapy of chemical cauterization with H₂O₂ at a minimum follow up of 24 months Results: Five-year disease free survival rate was 87 .5%. Mean follow up was 82.7 months and no patient developed metastases or died of disease. The mean final Musculoskeletal Tumor Society functional score was 27.5 (91 .6%) Conclusion: Extended curettage is an effective treatment strategy for low-grade central chondrosarcoma with improved functional outcomes and lower complication rates compared to wide re section and reconstruction