광탄성프린지 위상이동법을 이용한 에지균열판의 응력 해석

백태현,김명수,조성호 한국비파괴검사학회 2000 한국비파괴검사학회지 Vol.20 No.3

광탄성법은 투명한 물체에 힘을 가하면 복굴절 현상이 나타나며, 편광기에 의해 등색 및 등경프린지가 나타난다. 등색프린지를 이용하여 주응력차이 또는 평면상 전단응력을 계산할 수 있으며, 등경프린지에 의해 주응력 방향을 결정할 수 있다. 재래식 광탄성법에서는 특정한 위치에서 프린지를 개별적으로 측정해야 되는 불편한 점이 있어, 디지털 영상처리에 의해 광탄성 프린지로부터 전체적인 응력장을 해석할 수 있도록 프린지이동에 의한 위상이동법이 개발되었다. 프린지 위상이동법은 원형편광기에서 검광자를 0˚, 45˚, 90˚ 및 135˚회전시켜 프린지가 이동된 4개의 영상을 얻고, 이들로부터 위상차리로 나타나는 프린지분포를 측정한다. 본 연구에서는 프린지 위상이동법에 관한 광학적인 이론을 이용하여 압축하중을 받는 원형디스크의 프린지분포를 위상이동법으로 측정한 후 이론 값과 비교하였다. 또한, 인장하중을 받는 에지균열판의 응력분포 해석에 프린지 위상이동법을 적용하였다. 실험결과, 프린지 위상이동법으로 측정한 결과는 유한요소 해석 결과와 잘 일치하였다. 광탄성에서 위상이동법은 등경선과 평행하거나 직교하는 선상에서 응력분포를 용이하게 측정할 수 있으나, 일반적인 프린지 해석시 프린지 위상이동법을 적용하면 오차가 포함될 수 있다. The method of photoelasticity allows one to obtain principal stress differences and principal stress directions in a photoelastic model. In the classical approach, the photoelastic parameters are measured manually point by point. The previous methods require much time and skill in the identification and measurement of photoelastic data. Fringe phase shifting method has been recently developed and widely used to measure and analyze fringe data in photo-mechanics. This paper presents the test results of photoelastic fringe phase shifting technique for the stress analysis of a circular disk under compression and an edge-cracked plate subjectes to tensile load. The technique used here requires four phase stepped photoelastic images obtained from a circular polariscope by rotating the analyzer at 0˚, 45˚, 90˚ and 135˚. Experimental results are compared with those of FEM. Good agreement between the results can be observed. However, some error may be included if the technique is used to general direction which is not parallel to isoclinic fringe.

全蝎 抽出物이 血栓症, 全腦虛血 및 腦細胞毒性에 미치는 影響

백명현,황영근,정지천,강정준,김성훈 동국대학교 한의학연구소 1999 東國韓醫學硏究所論文集 Vol.8 No.1

본 실험은 전갈 추출물이 어혈병태 모델과 KCN으로 유발된 전뇌허혈, 뇌세포독성 등에 미치는 영향을 관찰하였다. 전갈은 Dextran에 의해 유도된 혈전으로 감소된 혈소판수, fibrinogen량, hemocrit치를 유의성 있게 증가시키고. 증가된 prothrombin time을 유의성 있게 단축시켰다. 전갈은 thrombin과 ADP에 의해 유도된 혈소판 응집을 억제하였으나 collagen에 의해 유도된 혈소판 응집에는 저해효과를 나타내지 않았다. 또한 collagen과 epinephrine에 의해 유도된 pulmonary embolism에 대하여 보호 효과를 나타내었다. 전갈은 KCN에 의한 전뇌허혈 유발 실험에서 혼수시간을 유의성 있게 단축시켰고, Amyloid β protein(25-35)에 의해 유도된 PC12 세포의 독성에 대하여 보호효과를 나타내었다. This following is effect of Buthus martensi Karsch (BMK) extract on dextran-thrombus model, KCN-induced coma, cytotoxicity of brain etc. BMK extract significantly increased number of platelet and fibrogen and significantly shortened the prothrombin time as compared with control group treated with dextran. BMK extract didn't affect the changes of hematocrit as compared with control group treated with dextran. BMK extract induced a significant inhibition of human platelet aggregation induced by thrombin and ADP but did not affect human platelet aggregation induced by collagen. BMK extract showed a protective effect on pulmonary thrombosis induced by collagen and epinephrine. BMK extract prolonged the duration of KCN-induced coma and showed a protective effect on cytotoxicity of PC12 cells induced by amyloid β protein(25-35) in a dose dependent manner. These results suggested that BMK extract might be usefully applied for prevention and treatement of thrombosis and brain damage.

一部 男子大學生들과 運動選手들의 一側優位性(左右差:手·足·體·眼)에 關한 比較硏究

백현중,윤태영,최중명,박순영 慶熙大學校 1991 論文集 Vol.20 No.-

This study is from March 1st, of 1988 to September 31, 1988. The subjects of study consists of students in general who are in attendance at university and all samples are selected at random. The total number of subjects counts to 187(sports man : 56, College students : 131) and the researcher measures and analyses the subjects' physique, physical strength, the test of dominance eye, the functional tests of hand, foot, body and eye. The results as follows : 1. Physical growth and development Mean values of body height are 177.19±5.01㎝ for sports man and 173.3±0.46㎝ for college student and superior to standard value of Korean. Mean values of body weight are 69.6.±6.17㎏ for sports man and 66.1±1.68㎏ for college student, and the mean values of chest girth are 91.86±4.83㎝ and 94.1±1.53㎝. Mean values of sitting height are 93.0±4.28㎝ and 93.3±1.05㎝. 2. Physical fitness Mean values of grin strength are 41.6±4.3 for right side and 44.0±6.0 for left side in sports man and 44.2±1.4 for right and 46.3±1.7 for left in college student. Mean values of arm strength are 29.7±3.9 for right and 31.8±2.9 for left in sports man 25.±1.4 or right and 28.7±1.9 for left in college student. Mean values of leg strength are 38.4±5.8 for right and 43.8±6.1 for left in sports man and 43.5±1.8 for right and 44.2±1.1 for left in college student. 3. Functional rate of foot, trunk, eye and hand As considered according to its functions, the rates of right foot, left foot, both of feet in both of the sports man and college student, total rates are each of 83.3%, 16.7%, 2.4% for sports man and 53.7%, 39.0%, 2.6% for college student. The rates of right side, left side, both of sides in both of the sports man and college student, the total rates are each of 53.3%, 37.4%, 6.7% for sports man and 39.1%, 46.1%, 5.1% for college student. The rates of right eye, left eye, both of eyes in both of the sports man and college student, the total rates are each of 53.6%, 31.7%, 4.1% for sports man and 53.3%, 20.8%, 22.7% for college student. The rates of right hand, left hand, both of hands in both of the sports man and college student, the total rates are each of 67.5%, 21.8%, 5.2% for sports man and 84.5%, 10.4%, 2.2% for college student, respectively. 4. Tests of dominance eye As considered according to tests of dominance eye, the results of right eye, left eye in both sports man and college student, results are each of 62.5%, 37.5% for sports man and 70.2%, 29.8% for college students, 67.9%, 32.1% for the total of sports man and college student, respectively.

광탄성 프린지 위상이동법을 적용한 디스크의 등경 및 등색프린지 분리법에 관한 시뮬레이션

백태현,김명수,조성호 한국비파괴검사학회 2001 한국비파괴검사학회지 Vol.21 No.2

광탄성법은 전체적인 응력장 해석을 위하여 가장 많이 사용되는 방법중의 하나이다. 광탄성법에서 주응력의 차이와 방향은 등색선과 등경선으로 나타난다. 재래식 방법으로는 주응력 방향은 평면 편광기의 편광자와 검광자를 동시에 회전시켜 수작업으로 측정하며, 이를 타디보간법이라 한다. 이러한 방법은 전체적인 응력장 해석시 매우 번거로우며 많은 시간이 걸린다. 재래식 광탄성법에서는 광탄성 프린지로부터 등경선을 분리시킬 수 없다. 본 연구에서는 광탄성이론을 Jones행렬로 나타내고 4단계와 8단계의 위상이동법에 대해서 기술하였다. 컴퓨터시뮬레이션을 통하여 압축하중을 받는 원형디스크의 광탄성 프린지로부터 등경선과 등색선을 분리시킬 수 있는 시험을 하였다. 디스크의 프린지는 응력-광 법칙에 의하여 생성하였다. 8단계 위상이동법으로 얻은 등경선과 등색선의 크기를 이론으로 계산한 값과 비교하였다. 컴퓨터 시뮬레이션으로부터 광탄성 프린지로부터 등경선과 등색선을 분리시킬 수 있는 가능성ㅇ르 예시하였다. Photoelasticity is one of the most widely used methods for whole field stress analysis. In photoelasticity, the difference and the directions of the principal stresses are given isochromatic and isoclinic fringe patterns. Conventionally, principal stress directions are measured by rotating the polarizer and analyzer of a plane polariscope at the same time. This is known to be the Tardy compensation method. This measurement can be very tedious and time consuming in whold field analysis. It is not possible to separate isoclincs from photoelastic fringes by conventional photoelastic technique. In this study, photoelastic theory is represented by Jones matrices and 4-steps and 8-steps phase shifting methods are described. A feasibility study using computer simulation is done to separate isoclincs and isochomatics from photoelastic fringes of a circular disk under diametrical compression. Fringe patterns of the disk are generated using stress optic law. The magnitudes of isoclincs and isochromatics obtained from 8-step phase shifting method are compared with those of theories. From computer simulation, it is verified to separate isoclincs and isochmatics from photoelastic fringes.

동형 모더나이트 상에서 일산화탄소 산화반응에 대한 속도론

정명수,이창용,최고열,하백현 漢陽大學校 環境科學硏究所 1989 環境科學論文集 Vol.10 No.-

모더나이트에 동을 이온교환 및 담지시킨 후 환원·산화 처리를 하여 동의 상태를 변화시킨 촉매에 대해 일산화탄소 산화반응의 속도론적인 고찰을 행하였다. 이온교환 촉매나 담지촉매 모두 동의 상태와는 관계없이 일산화탄소에 관한 반응차수는 1차이고 산소에 관한 반응차수는 0차였다. 이온교환 촉매의 경우는 수소로 환원시켜 동이 금속상태로 존재할때와 이를 재산화시켜 산화동 상태로 존재할때는 활성화에너지가 각각 16.4 및 20.3으로 비교적 큰 값을 나타냈으나 동의 담지촉매의 경우는 동이 금속일 때나 산화물 상태 모두 12∼13kcal/mole로 비슷한 값을 나타냈으며 이온교환 촉매보다 상당히 감소함을 알 수 있었다. 이와 같은 결과는 이온교환 촉매의 경우는 동이 제올라이트내부에 대부분 존재하는 반면, 담지촉매의 경우는 제올라이트 결정 표면에 존재하기 때문에 활성을 증가시키는 것으로 생각된다. Kinetics of oxidation of carbon monoxide over copper mordenite was carried out at the temperature range between 373K-443K in the micro-catalytic reactor. The experimental results indicated that the reaction order, with respect to carbon monoxide and oxygen was first and zero order respectively, regardless of the valence states such as copper metal, copper ion and copper oxide on the mordenite. The activation energy for metal-copper mordenite which is obtained by the ion-exchange revealed 20kcal/mol. But if this was reoxidized under the oxygen it decreased to 16.6kcal/mol. The activation energy of metal-copper mordenite which was obtained by impregnation and its reoxidized one under the oxygen were 12.2kcal/mol and 13.3kcal/mol respectively.

스펙클 간섭계를 이용한 시편 후면의 변형에 의한 변위 측정

김명수,백태현 국립7개대학공동논문집간행위원회 2005 공업기술연구 Vol.5 No.-

Speckle interferometry with 4-step phase shift method has been used for measurement of displacement in specimen using advantage of optical method that is whole filed and non-contact measurement. In this research, a specimen used for optical experiment has a deformation in its rear side, so that the deformation is invisible from the front side of specimen. By use of optical experiment for speckle interferometry with 4-step phase shift method, the invisible deformation is easily found, and in-plane displacement and out-of-displacement of specimens caused by the deformation are measured. It is shown that the measured displacements are quite comparable to the displacements that are calculated theoretically.

스펙클간섭계를 이용한 변위측정

김명수,백태현 국립7개대학공동논문집간행위원회 2003 공업기술연구 Vol.3 No.-

Measurement of displacement is studied by use of speckle interferometry with a laser. A quarter wave plate that is a birefringent optical device is investigated for phase shifting method in speckle interferometry to measure in-plane displacement or out-of-plane displacement on a specimen. Results of optical experiment for measurement of in-plane displacement are quite comparable to expected results. Also, the quarter wave plate for measurement of out-of-displacement is analyzed for phase shifting method in speckle interferometry.

Lactobacillus casei YIT9018로부터 분리ㆍ정제한 Whole Peptidoglycan의 In Vitro 항종양활성

金昌漢,李明燮,高時煥,朴相瑨,朴圭炫,白永振 건국대학교 생명과학연구원 1995 생명과학지 Vol.2 No.-

In vitro antitumor activity of whole peptidoglycan(WPG) purified from Lactobacillus casei YIT9018 was examined by clonogenic assay. WPG had antitumor activity against five human tumor cell lines and three mouse tumor cell lines. Antitumor activity of WPG against human tumor cell lines such as A-427, SKMES-1, SF-188, FARROW and RAJI was observed at 300, 1,000, 600, 800 and 900㎍/ml concentration, respectively. Antitumor activity of WPG against mouse tumor cell lines such as 3LL, S-180 and P388 was observed at 100, 500 and 1,000㎍/ml concentration, respectively.

피로와 의료이용, 업무상 사고 및 질병결근

장세진,고상백,강동묵,김성아,정진주,이철갑,강명근,현숙정,조정진,차봉석,박종구 大韓産業醫學會 2005 대한직업환경의학회지 Vol.17 No.4

Objectives: This study examined the relationship of fatigue to medical utilization, occupational accident and sickness absence. Subjects and Methods: Data were obtained from the National Study for Development and Standardization of Occupational Stress (NSDSOS Project, 2002~2004). A total of 30,146 employees categorized within the Korean Standard Industrial Classification and the Korean Standard Occupational Classification were recruited. A structured-questionnaire was used to assess the participants' sociodemo-graphics, job-related factors, health-related behaviors, personality trait, self=perceived fatigue (MFS) and the frequency of medical utilization, occupational accident and sickness absence. Data on medical utilization and occupational accident were confirmed from company health records. Chi-square test and logistic regression analysis were used to elucidate the relationship of self-perceived fatigue to medical utilization, occupational accident and sickness absence. Results: In logistic regression analyses, self-perceived fatigue was associated with medical utilization (outpatient), occupational accident and sickness absence although the strength of the associations was higher in the blue collar workers except for medical utilization. For medical utilization, the white collar worker's adjusted odds ratios of outpatient utilization for workers scoring in the third quartile and the highest quartile, compared to workers scoring in the lowest quartile were 1.50 (95% CI: 1.20-1.87) and 2.16 (95% CI: 1.69-2.75), respectively. The blue collar workers' adjusted odds ratios of outpatient utilization for workers scoring in the second (OR: 1.23, 95% CI: 1.06-1.43), third (OR: 1.42, 95% CI: 1.22-1.66) and highest quartile (OR:1.83, 95% CI: 1.55-2.17), respectively, compared to workers scoring in the lowest quartile were statistically significant. However, no associations were found between fatigue and inpatient utilization for either the white or blue collar workers. The blue collar workers' adjusted odds ratios of being injured for workers scoring in the second, third and highest quartile were 1.41 (95% CI: 1.00-2.00), 1.57 (95% CI: 1.10-2.22) and 2.41 (95% CI: 1.69-3.44), respectively, compared to those scoring in the lowest quartile, but, those of the white collar workers were not significant. There was more likely to an increased risk of sickness absence in workers scoring in the second, third and highest quartile compared to those scoring in the lowest quartile in both white and blue collar workers, but the magnitudes of risk were higher in the blue collar workers than the white collars workers. Conclusion: This result suggests that fatigue is a determinant predictor of medical utilization, occupational accident and sickness absence, and that the pattern of risks for the three outcomes differs according to the occupational type. Some limitations of this study and considerations for future study were also discussed.

Lactobacillus casei YIT9018로부터 분리, 정제한 Whole Peptidoglycan의 In Vitro 항종양활성

金昌漢,李明燮,高時煥,朴相瑨,朴圭炫,白永振 건국대학교 생명과학연구원 1995 생명과학지 Vol.2 No.1995