음향초음파와 음향방출에 의한 복합재료-금속 접착접합부의 피로손상 평가

권오양,이경주 한국비파괴검사학회 2001 한국비파괴검사학회지 Vol.21 No.4

복합재료-금속 접착접합부가 사용 중 반복 하중을 받을 때 발생하는 피로 손상도를 음향초음파(acousto-ultrasonics; AU)법과 음향방출(acoustic emission; AE)법을 이용하여 평가하였다. 피로시험에는 단일겹치기(single-lap) 시험편을 사용하였으며, AU법을 통해 취득한 신호로부터 음향초음파변수(acousto-ultrasonic parameters; AUP)와 피로손상과의 상관관계 곡선을 얻고, AE법에서는 누적 AE events를 통한 피로손상과의 상관관계 곡선을 얻어, AU법과 AE법의 결과를 비교하였다. 이 곡선들은 피로손상에 의한 고분자기지 복합재료의 강성 저하(E/E0)를 나타내는 곡선과 매우 유사하며, 이를 바탕으로 피로 손상도의 예측과 잔여 수명의 예측이 가능하다. 또한 피로 하중의 초기 단계와 피로손상의 누적에 의해 급격한 변화가 나타나는 단계의 파형과 주파수 성분을 비교하여, 피로 파괴의 마지막 단계에서 나타나는 신호 중에는 본격적인 피로손상에 의해 발생하는 AE 신호 성분이 포함되어 있음을 확인할 수 있었다. A correlation between fatigue damage and acousto-ultrasonic (AU) parameters has been obtained from signals acquired during fatigue loading of the single-lap joints of a carbon-fiber reinforced plastic (CFRP) laminates and as A16061 plate. The correlation showed an analogy to those representing the stiffness reduction (E/E0) of polymer matrix composites by the accumulation of fatigue damage. This has been attributed to the transmission characteristics of acoustic wave energy through bonded joints with delamination-type defects and their influence on the change of spectral content of AU signals. Another correlation between fatigue cycles and the spectral magnitude of acoustic emission (AE) signals has also been found during the final stage of fatigue loading. Both AU and AE can be applied almost in real-time to monitor the evolution damage during fatigue loading.

핸드스프링 무릎굽혀 앞공중돌기동작과 몸펴 앞공중돌기동작의 운동학적 비교분석

권오석,윤양진 부산대학교 사범대학 2002 교사교육연구 Vol.41 No.-

In this study, 4 gymnasts who were students of B University at that time were taken and their performance of handspring salto forward tucked and handspring salto forward stretched at through 3 dimensional movement analysis to tell the duration for each phase of the movement, the movement of the articulation of the body, the tract of moving center of the body, and its kinematic element. It is all to provide basic data for efficient training of gymnasts and the findings are as follows: 1. The time duration for phase 1 and 2 differed each other and faster landing on hands in forward handspring salto forward stretched than in forward salto with the body bent helped the straight-line movement change to circular movement giving the handspring a big circular movement, and forward jumping on feet with rapid upright of the upper body maximized the circular radius on the axis of the jaw, contributing to rapid backward circular movement of the lower part of the body. 2. In the observation of the position of the body center, the sway of the body center and the power dispersion was smaller in general in forward salto with the body stretched than in forward salto with the body bent. And in its forward and backward position, it showed lower position in handspring phase of 1 and 2, but higher in the salto of phase 3, 4 and all these contributed to bigger and more stable circular motion. 3. Articulation angle of the body in each phase of handspring forward salto with the body bent and in forward salto with the body stretched appeared to be different through 5 phases. It had more centripetal force in forward salto with the Elbows, shoulders, hips, knees having more curve. In forward salto with the body stretched, centrifugal force appeared to be strong with the elbows, shoulders, hips, knees all being extended. To summarize, Handspring forward salto with the body bent seems to have curved articulation and be slow, while in forward salto with the body stretched, its circular movement appeared be faster with speedy landing on hands, extended knees angle for good jump, and with accelerated hips articulation. Handspring forward salto with the body stretched appeared to enhance its technical performance with far-reaching circular motion. Therefore, forward salto with the body stretched is considered to produce more gracious and dynamic motion than forward salto with the body bent does.

조기위암에서 침윤, 유형 및 분화도에 따른 p53, bcl-2의 발현

권오선,조현득,오미혜,김의한,양승하 순천향의학연구소 2006 Journal of Soonchunhyang Medical Science Vol.12 No.2

Purpose: For evaluation of the role of tumohgenesis of p53 over expression and bcl-2 inhibition in early gastric cancer, the immunohistochemical tissue status of 31 primary early gastric cancer patients was investigated, and also the association between p53 , bcl-2 expression status and clinicopathologic parameters was analyzed for evaluation of prognostic relevance. Materials and Methods: DO7, a monoclonal antiserum to p53 protein and clone 124, monoclonal antibody to bcl-2 protein were used for the immunohistochemical analysis in 31 primary early gastric cancer tissue. The expressions were scored and divided into negative, positive, low expression, and over expression. Results: The clinocopathologic parameters; tumor depth of invasion, histologic type and differentiation were not related with the expression status of p53 and bcl-2. In 31 cases, the p53 over expression was 14 cases(45.2%), and the bcl-2 positive expression was 15 cases(48.4%), and 9 cases(29.0%) were the status of p53 over expression and bc1-2 positive expression. Conclusions: These results suggest that altered cell cycle and apoptosis control by p53 and bcl-2 may be an event in carcinogenesis of early gastric cancer but there are many other mediators that may fascilitate tumorigenesis.

노후항공기의 비파괴시험 평가

권오양 韓國非破壞檢査學會 1999 한국비파괴검사학회지 Vol.19 No.1

전 세계적으로 항공기의 노후화에 따른 안전성 확보와 수명연장을 위한 대책 연구가 활발하다. 미국의 경우 군용기(주로 수송기)의 평균수명은 40년을 넘어서고 있으며 이들은 아지고 20-30년 더 사용될 예정이다. 민간항공기의 경우에도 군용기만큼은 아니지만 노후화하고 있기는 마찬가지이다. 수명연장을 위해 여러 가지 비파괴검사 기술이 활용되고 있으며, 새로운 비파괴시험·평가·검사 방법들이 속속 개발되고 있다. 항공기의 안전을 위험하는 기체구조 손상의 2대 주범으로는 부식과 피로를 꼽을 수 있으며, 이를 탐지하고 평가하기 위한 경제적인 검사방법에 대한 연구가 미국을 중심으로 활발하게 진행되고 있는데, 이에 대한 최근 현황을 살펴본다.

工團地域 小河川의 底泥中 重金屬 含量

權五億,梁成鎬,姜善泰 대구산업정보대학 1992 논문집 Vol.6 No.-

This study was carried out to investigate the contents of six heavy metals (Cd, Cr, Cu, Mn, Pb and Zn) in sediment collected at seven sites of 3-Gongdan stream receiving industrial wastewater. The mean Zn, Cu, Mn, Pb, Cr and Cd contents in sediment of all sites investigated was 1496.6mg/kg, 764.4mg/kg, 562.0 mg/kg, 231.6 mg/kg, 37.3 mg/kg and 9.5 mg/kg, respectively. It can be esteimated that the high amount of heavy metals is possibly due to the industrial wastewater, and alkaline pH water when most of the heavy metals are precipitated.

ASNT 60주년 기념식과 추계학술발표회 및 기기전시회 참관기

권오양 한국비파괴검사학회 2002 한국비파괴검사학회지 Vol.22 No.1

미국비파괴검사학회(ASNT)가 올해로 창립 60주년을 맞이하였다. 지난 10월 ASNT의 본부가 있는 오하이오주 컬럼버스에서 개최된 ASNT 추계학술발표회 겸 기기전시회에 한국비파괴검사학회를 대표하여 정기총회, 학술발표회 등 행사에 참석하고 ASNT 사무국, 기기전시회를 둘러본 내용을 지면을 통하여 보고하고자 한다. 워낙 회의에는 ASNT와 자매결연을 맺은 세계 여러나라 학회의 대표들이 초청되었으나 공교롭게도 시기가 9.11 테러사태 직후였던 관계로 캐나다, 멕시코, 컬럼비아 등 몇몇 미주권 국가 외에는 모두 참가를 취소하여 실제로는 필자가 거의 유일하게 다른 대륙의 외국학회 대표인 셈이었다.

매트운동에서 핸드스프링 앞수완동작의 운동학적분석

권오석,윤양진 釜山大學校 附設 體育科學硏究所 2002 體育科學硏究所 論文集 Vol.18 No.1

In this study, 4 gymnasts who were students of B University at the same time was taken and their performance of forward Handspring salto with body stretched was looked at through 3 dimensional of the body, the tract of moving and its kinematic element. It is all to provide basis data for efficient training of gymnasts and the findings are as follows: 1. From the examination of the sequence of duration phase, it appeared that in phase 1, the superior group had longer duration with long strider in home step, in phase 2, they bent their upper body making big shoulder angle and changed the straight-line motion to circular motion. And it appeared to result in efficient circular motion while in flight phase of 4 and 5. 2. It appeared that in the event 2 in which the movement of support with hands took place, the Superior group had bigger shoulder angle so that the Handspring movement was faster in its rotation on the axis of hands supporting. In event 3 of jump in feet, the hips angle was big enough to produce with its weight sufficient pressure on feet to maximize the reaction of the floor. 3. For the speed in each phase, the Superior group spurred rapid speed with the hips angle curved a little bit in event 4 in which the body made vertical angle to the floor while in handspring salto forward piked movement of the body and in event 5, the hips angle extended rapidly producing good rotation speed. In summery of all the elements considered above, big strider with the body bent to produce decisive support on the hands seemed to result in increased rotation speed in handspring, bigger pressure on feet, and good speed in handspring salto forward stretched.

조기위함에서 침윤, 유형 및 분화도에 따른 p53, bcl-2의 발현

권오선,조현득,오미혜,김의한,양승하 순천향대학교 의학연구소 2006 Journal of Soonchunhyang Medical Science Vol.12 No.2

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음향방출을 이용한 저어널 베어링의 조기파손감지(Ⅱ) : Part Ⅱ : Intervention of Foreign Particles in Lubrication 윤활유 이물질 혼입의 영향 및 감시

권오양,윤동진,김경웅,정민화 韓國非破壞檢査學會 1994 한국비파괴검사학회지 Vol.14 No.2

일반적으로 회전기기의 저어널 베어링 부분은 윤활유 공급의 부족이나 윤활층에 이물질이 혼입되면 시스템의 고장이나 가동중단 등의 원인이 되기도 한다. 따라서 베어링 손상에 기인하는 사고와 관련된 안전운전 문제와 유지비용의 절감을 위해 여러가지 파괴 및 비파괴시험법들이 사용되어 왔다. 본 연구에서는 저어널 베어링에서 가장 발생하기 쉬운 윤활층에의 이물질이 혼입에 의해 야기되는 베어링 파손의 조기검출을 위해 음향방출 기술을 적용하였으며, 전보의 연구에 이어 좀더 정량적이고 체계적인 실험을 수행하였다. 실험실용으로 직접 제작한 모의베어링 시스템을 이용하여 여러 형태의 인위적인 이물질 흔입 상태를 만들어 실험하였으며 베어링 손상 및 결함 형태의 해석을 위해 AE rms level, 파형분석, AE 변수 등의 여러 파라메터를 사용하여 분석 고찰하였다. 그 결과 AE rms level의 변화가 이물질 흔입의 영향에 민감함을 보여주었으며 AE변수등 다른 정보들로부터 손상 원일별로 신호형태를 확인할 수 있었다. Journal bearings in the rotating machineries are vulnerable to the contamination or the insufficient supply of lubricating oil, which is likely to be the cause of unexpected shutdown or malfunction of these systems. Various destructive and nondestructive testing methods had been used for the reduction of maintenance cost and the operational safety problems due to the accidents related to bearing damages. In this experimental approach, acoustic emission monitoring in employed to the detection of incipient failure caused by intervention of foreign particles most probable in the journal bearing systems. Experimental schedules for the intervention of foreign particles was composed to be more quantitative and systematic than last study in consideration of minimum oil film thickness and particle size . The experiment was conducted under such designed conditions as inserting alumina particles to the lubrication layer in the simulated journal bearing system. Several parameters such as AE rms level, waveform, AE energy distribution and other AE event parameter are used for analysis and characterization of damage source. The results showed that the history of damage was well correlated with the changes of AE rms level and the types of damage source signal can be verified using other informations such an waveform, distribution of AE parameter etc.

핸드스프링 몸펴 앞공중1회 비틀기 동작의 운동학적 분석

권오석,윤양진,서국웅 한국운동역학회 2001 한국운동역학회지 Vol.11 No.3

The purpose of this study was to determine the mechanical factors that govern success in the performance of handspring salto forward stretched with 1/1 turn. The subjects were two all-around gymnasts who registering sophomore in college. By means of three-dimensional film analysis, it was to analyze the sequence of duration phase, angle change of the body joint, and body of the center gravity during performance of handspring. The findings of this study were following as: 1. The sequence of duration phase indicated that Sub.1 has more stride than Sub.2 in the first interval and the shoulder joint has greatly extended, in which the linear movement at take off is transferred into the rotation movement with supporting on the ground. 2. In the several states, sub.1 has more flexor on the elbow of the left on the center of rotation, more twisted on the shoulder joint far from the axis of rotation than sub.2, in which resulted in constant twisting momentum. 3. Body center gravity showed to be low until supporting hands on the ground with taking steps. It was therefore to generate greatly the initial force of handspring based on the rotation of hands. In the fourth, upper extremities is bending forward and lower extremities is extending backward. These results were therefore of interest to determine the magnitude of flight in the air with support of greatly rotation. Of all the variables analyzed, the large stride, high rotation of vertical velocity based on axis of hands, and bending upper extremities forward, are important determinant for successful results.