저항 점 용접 로봇에서 서보건의 가압력 제어를 통한 용접 강도 향상에 대한 연구

박영환,이종구,이세헌,Park, Young-Whan,Lee, Jong-Gu,Rhee, Se-Hun 대한용접접합학회 2006 대한용접·접합학회지 Vol.24 No.6

Resistance spot welding is widely used for joining sheet metals in the automotive manufacturing process. Recently, servo-gun is used to increase the productivity and precise control the acting force. However, force control mechanisms have not been investigated with servo-guns until now. In this paper, it is proved that servo-motor current is proportional to torque and by experiment, experimental equation between servo-motor current and electrode force was derived. Algorithm for feedback control of electrode force was suggested using current measurement. In addition, applying soft touch method to this system the impact between electrode and specimen, which is the problem of air gun, could be reduced. Indentation made the force decrease in holding time of resistance spot welding. In order to overcome this problem, force compensation using the servo gun was used and it improved weld strength in good welding current range.

자동차 차체 적용을 위한 레이저-아크 하이브리드 용접의 동축 모니터링 시스템 개발

박영환,이세헌,김철희,Park, Young-Whan,Rhee, Se-Hun,Kim, Cheol-Hee 대한용접접합학회 2009 대한용접·접합학회지 Vol.27 No.6

In this paper, the coaxial monitoring system to capture image of weld pool was developed in laser-arc hybrid welding. In order to obtain the reliable image, green laser was used as a illumination system and measuring components such as band pass filter, ND (Neutral Density) filter and shutter speed was designed and optimized. Using this monitoring system, weld pool images were captured according to laser power, welding speed, welding current and interspace between laser and arc through the experiment. ANOVA (Analysis of Variation) was carried out to identify the influence of process variables on bead widths extracted from captured images of monitoring system. Welding speed and current were major factor to affect weld pool.

한힌샘 주시경선생의 생애와 학문세계

박영환,Park, Yeong-Hwan 대한출판문화협회 1991 출판저널 Vol.92 No.-

주시경은 국어의 연구와 운동을 병행했다는 점에서 대개 국엉ㄴ구에만 그친 다른 학자들과 구별된다. 그는 연구에 매진했을 뿐 아니라 끊임없이 후학들에게 자신이 고구한 바를 가르쳤으며, 나아가 겨레에게 국어에 대한 올바른 이해와 사랑의 정신을 심어주기 위해 애썼다.

소양(瘙痒)의 병인(病因), 병기(病機)에 관한 문헌적(文獻的) 고찰(考察)

박영환,백태현,김성현,Park, Yeong-Hwan,Baek, Tae-Hyeon,Kim, Seong-Hyeon 대한한방내과학회 1995 大韓韓方內科學會誌 Vol.16 No.1

레이저 용접에서 용접 공정 모니터링 기술

박영환,Park, Young-Whan 대한용접접합학회 2012 대한용접·접합학회지 Vol.30 No.1

방사선 전신조사 환자의 말초혈액 검사를 통한 급성장애 지표개발에 관한 연구

박영환,Park, Young-Hwan 대한방사선치료학회 2001 大韓放射線治療技術學會誌 Vol.13 No.1

골수이식 수술을 위해 10MV X-ray로 전신 방사선 치료 환자 중 18명을 무작위 추출하여 조사한 후 25일간 말초혈액의(백혈구, Seg. neutrophil, 임파구, 적혈구, 헤모글로빈, 헤마토치, GOT, GPT 등) 수치변화를 대조군 32명과 본인의 방사선 조사전과 비교하여, 고선량의 방사선 피폭이 인체의 말초혈액에 미치는 영향을 평가하였다. 말초혈액 변화 중 백혈구는 방사선 치료 전 검사 $2.51{\times}103{\pm}1.29{\times}103/mm^3$에 비해 $0.22{\times}103{\pm}0.19{\times}103/mm^3$로 최저 $8.63\%$을 나타냈고, 대조군 $7.17{\times}103/mm^3{\pm}1.46{\times}103/mm^3$에 비해서는 $6.35\%$로 낮은 수준을 나타내어 통계적인 유의성이 있었다(P<0.01, r2=0.9151). 백혈구 형태학적 검사 중 Seg. neutrophil은 조사 전 $69.00{\pm}25.60\%$에 비해 $14.17{\pm}21.60\%$로 최저 $20.53\%$수준으로 낮았고, 대조군 $58.09{\pm}7.62\%$에 비해서는 $24.39\%$ 수준으로 감소하였다(P<0.05, r2=0.6316). 임파구 수는 조사 전 $20.29408{\pm}21.15\%$에서 $79.91{\pm}27.30\%$로 최고 3.94배로 높게 나타났고, 대조군 $33.46{\pm}6.79\%$에 비해 2.39배 높게 나타났다(P<0.05, r2=0.7337). 적혈구 수의 변화는 조사 전 $3.18{\times}106{\pm}0.41{\times}106/mm^3$과 대조군 $4.66{\times}106{\pm}0.43{\times}106/mm^3$에 대해 낮은 수준을 나타냈으나 통계적인 유의성은 없었다(P>0.05). 헤모글로빈과 헤마토치의 수치도 조사전과 대조군에 대한 비교에서도 낮게 나타났으나, 모두 통계적인 유의성은 없었다. 그러나 조직학적 검사인 GOT와 GPT값은 조사전과 대조군에 비해 모두 통계적인 유의성이 있었다(P<0.05). 이와 같이 고선량의 방사선 전신 조사 후 말초 혈액 중 백혈구의 수치가 일정 기간에 급격 히 감소하였고, 백혈구 형태학적 검사중 Seg. neutriphil과 임파구수치도 현저하게 감소하였다. 따라서 본 연구 결과로 인체에 고선량의 방사선에 피폭되었을 때, 일반적인 말초혈액 검사를 이용하여 방사선 급성장해 유발 가능자를 1차 적으로 선별 할 수 있는 지표 개발 가능성을 제시하였다고 사료된다. In those patients who underwent radiation therapy with 10 MV X-ray for bone marrow transfer, compared the effect of high dose irradiation on peripheral blood were investigated in randomly selecting 18 patients. thus, changes in the levels of peripheral blood (WBC, Seg. neutrophil, Lymphocyte, RBC, Hemoglobin, Hematocrit ratio, GOT, GPT) were observed for 25 days after irradiation with the peripheral blood levels before irradiation in these patients and in 32 controls. Among changes in peripheral blood, the level of WBC was $8.63\%$ after radiation therapy with as much decrease as $0.22{\times}103{\pm}0.19{\times}103/mm^3$ compared with $2.51{\times}103{\pm}1.29{\times}103/mm^3$ before radiation therapy, and was only $6.35\%$ of $7.17{\times}103/mm^3{\pm}1.46{\times}103/mm^3$ in the controls, showing statistical significance (P<0.01, r2=0.9151). In the morphologic test of WBC, the level of Seg. neutrophil was decreased as much as to $20.53\%$ with $14.17{\pm}21.60\%$ compared with $69.00{\pm}25.60\%$ before irradiation, and decreased down to $24.39\%$ compared with $58.09{\pm}7.62\%$ in the controls (P<0.05, r2=0.6316). The number of lymphocyte increased as much as 3.94 folds at $79.91{\pm}27.30\%$ compared with $20.29{\pm}21.15\%$ before irradiation and was 2.39 times higher than $33.46{\pm}6.79\%$ in the controls (P<0.05, r2=0.7337). Although the change in the number of RBC was little with $3.18{\times}106{\pm}0.41{\times}106/mm^3$ before irradiation and $4.66{\times}106{\pm}0.43{\times}106/mm^3$ in the controls, no statistical significance was present (P>0.05). In addition, The number of hemoglobin was low compared with before irradiation and with the controls, but none showed statistical significance (P>0.05). Similarly, although the hematocrit ratio was low compared with before irradiation and with the controls, no statistical significance was present (P>0.05). In the values of the histologic examinations GOT and GPT, there is statistical significance between those from with before irradiation and with the controls (P<0.05). Thus, among peripheral blood, the number of WBC decreased drastically for a certain period after total body irradiation with high dose radiation, and the levels of Seg. neutriphil and lymphocyte decreased significantly after irradiation in the lymphocyte morphologic test. The results of the present study suggest that the possibility of developing the first to determine initially those patients who might develop radiation acute impairment using the usual peripheral blood test of patients to be exposed to high dose irradiation.

레이저 용접의 모니터링 기술

박영환,Park, Young-Whan 대한용접접합학회 2009 대한용접·접합학회지 Vol.27 No.1

BMT 구동장치의 유한요소해석 및 형상변수 최적화

박영환,곽재섭,엄가정,Park, Young-Whan,Kwak, Jae-Seob,Jiating, Yan 한국생산제조학회 2010 한국생산제조학회지 Vol.26 No.2

Base-mounted type(BMT) driving assembly in CNC machine tools is an indispensable part to improve productivity by reducing tool changeover time and to meet the ever-increasing demand of precision machine tools. This study aimed to perform finite element analysis and geometric parameter optimization to improve the efficiency of BMT driving assembly. First, simulations for three-dimensional structural and vibration analysis were performed using ANSYS/Workbench on the initial geometric models of BMT driving assembly. After analyzing stress and deformation concentration zones, several new geometrical models were designed and evaluated by design of experiments and ANSYS/DesignXplorer. Through a series of analysis-evaluation-modification cycles, it was seen that designed models were effective in determining optimal geometry of BMT driving assembly.

침금동인(鍼金銅人)의 제작(製作)에 대한 고찰(考察)

박영환,Park, Yung-Hwan 한국의사학회 2012 한국의사학회지 Vol.25 No.2

The Chimgeumdongin(鍼金銅人) is a Acupuncture Bronze Man that casted by Choe Cheonyak(崔天若) the meister and directed by O Jicheol(吳志哲) the royal chief acupuncture doctor of Chosen dynasty(朝鮮) in 1741. Choe Cheonyak casted the Chimgeumdongin at least 12 parts. After welding the parts, engrave the names of acupuncture point on it. It is suggested that there maybe one or more Wooden Acupuncture Man that remedy mistakes for a longtime before 1741. This became a prototype of Chimgeumdongin. The contents of Chimgeumdongin's acupuncture points are equal to <Buzhutongrenjing : 補註銅人經> which was recited by royal acupuncture doctors for hundreds years. Chimgeumdongin rigorously apply the bone proportional unit measurement of <the chapter on Measurement of the bone, chapter 14 of the Lingshu : 靈樞.骨度篇>. and the range of error was between 0.01cm~1.67cm. Specially, they made it's head 1.34 times bigger, by long experience. Accoding to <Seungjeongwonilgi : 承政院日記>, the Chimgeumdongin was used for training inexperienced royal acupuncture doctors. As shown above, the Chimgeumdongin could be represents standard acupuncture technology of Chosen dynasty.

학술중계-인공피혁 선진기술도입및 개발시급

박영환,Park, Yeong-Hwan 한국과학기술단체총연합회 1988 과학과 기술 Vol.21 No.2