http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
정석영(S.Y. Jung),윤성준(S.J. Yoon) 한국전산유체공학회 2008 한국전산유체공학회 학술대회논문집 Vol.2008 No.-
For simulation of a wing unfolding motion for the various aerodynamic conditions, equation governing unfolding motion and moments applying to the unfolding wing were modelled. Aerodynamic roll moment consists of the static roll moment and the damping moment, which were obtained through wind tunnel tests and numerical analyses respectively. Panel method was used to compute the roll damping coefficient with twisted wing, whose deflection angle was equivalent to angle of attack due to the deployment motion. Roll damping coefficient is a function of angle of attack, sideslip angle, and deployment angle but not of angular velocity of deployment. Simulation with aerodynamic damping model gave more similar deployment time compared to wing deployment test results.
수술적 폐경과 자연 폐경에서 호르몬 보충요법 후 골반응의 차이
서유석(Y. S. Suh),박형무(H. M. Park),박선영(S. Y. Park),윤성준(S. J. Yoon),허민(M. Hur) 대한산부인과학회 1999 Obstetrics & Gynecology Science Vol.42 No.10
목적: 수술적 폐경은 난소 기능의 갑작스럽고 완전한 소실로 인하여 골밀도의 변화에 있어서 자연 폐경과는 다른 양상을 보이게 되고 이로서 호르몬 보충요법에 의한 치료효과도 다르게 나타나게 될 것으로 생각하고 이를 확인하고자 하였다. 연구 방법: 중앙대학교 용산병원 폐경기 클리닉에서 수술적 폐경을 한 73명의 여성을 대상으로 하여 접합마 estrogen 0.625mg을 사용하여 호르몬 치료를 1년간 시행하고 그 전후에 척추와 대퇴경부의 골밀도를 측정하여 자연 폐경 여성과 비교하여 보았다. 28명의 환자에서는 QCT를, 43명의 환자에게는 DXA를 사용하여 골밀도를 측정하였으며 1) 골밀도의 변화 2) 폐경기간에 따른 호르몬 보충요법에의 반응 정도 3) 호르몬 보충요법에도 불구하고 골밀도의 감소를 보이는 여성의 빈도를 비교하였다. 결과 : 1) 수술적 폐경여성에서는 estrogen 단독요법으로 척추의 골밀도가 QCT에서는 6.86%가 감소하였으며 DXA에서는 1.15%가 감소하였다. DXA로 측정한 대퇴경부의 변화는 1.65% 감소한 것으로 나타났다. 2) QCT군에서 2년 이하의 폐경기간을 가진 22명의 여성의 골밀도는 7.89%가 감소하여 4.33%가 증가한 폐경여성과 유의한 차이를 보였으며 2년 이상의 폐경기간을 가진 여성에서는 폐경 경로와 관계없이 유의한 차이를 보이지 않았다. DXA군에서는 2년 이하의 폐경기간을 가진 여성에서 척추와 대퇴경부에서 2.80%와 3.08%가 감소한 것으로 나타나 2.36%와 1.84%가 증가한 자연폐경군에 비하여 유의한 차이가 있었다. 폐경기간 2년 이상에서는 수술적 폐경군에서 4.31%, 3.10% 증가로 5.00% 증가, 2.99% 증가로 나타난 자연 폐경군과 유의한 차이가 없었다. 3) 호르몬 치료에도 불구하고 유의한 정도로 골밀도가 감소한 여성의 빈도는 수술적 폐경후 2년 이내의 폐경기간을 가진 여성이 QCT에서 59.0%, DXA에서 척추가 60.6%, 대퇴경부가 56.7%로 반 이상의 여성이 호르몬 치료에도 불구하고 골밀도가 유의한 감소를 하였으며 자연 폐경 여성과 비교하여 훨씬 높은 빈도를 보였다. 결론: 수술적 폐경은 자연 폐경과 달리 급속한 골밀도의 변화가 나타나므로 좀 더 적극적이고 철저한 검사와 치료로 초기의 골밀도 감소를 예방하여야 할 것이다. Objectives: surgical menopause, state of both oophorectomy, shows some different features compared to natural menopause. The purpose of this study was to compare effectiveness of hormone replacement therapy(HRT) in surgical menopause with it in natural menopause. Methods: bone mineral density was assessed in 71 surgically menopausal women at the time of starting HRT and was repeated after one year HRT. 28 were evaluated by quantitative computed tomography (QCT) and 43 were done by dual energy X ray absorptiometry (DXA). We divided the subjects into two groups according to the intervals between oophorectomy and the start of HRT(group 1: within 2 years after surgery, group 2: more than 2 years after surgery). Results: QCT-group 1 included 22 subjects, QCT-group 2 included 6. In group using DXA, 33 subjects were in group 1, and 10 in group 2. In natural menopause, 76 subjects were included and their bone mineral densities were assessed pre- and post-HRT(QCT: group 1, n=13, group 2, n=13, DXA: group 1, n=32, group 2, n=18) 1) Incidences of significantly decreased BMD in spite of HRT in surgically menopaused women were 59.0% in QCT-group 1, 60.6% in spine of DXA-group 1. These incidences are higher than those of natural menopause. 2) After 1 year estrogen replacement in surgical menopause, BMD decreased 6.86% by QCT and 1.15% by DEXA. But, surgical menopause women in group 1, BMD by QCT decreased 7.89%, spine BMD by DXA decreased 2.80%, femur neck BMD decreased 3.08%. Contrary to these results, BMD of natural menopause women increased 4.33%, 2.36%, and decreased 1.83%, respectively. Conclusion: Usual dosages of HRT cannot prevent acute bone loss effectively after both oophoectomized women. So, additional therapy will be prescribed to surgically menopaused women.
화학반응을 수반하는 극초음속 희박류 유동의 직접모사법 개발
정찬홍(C. H. Chung),윤성준(S. J. Yoon) 한국전산유체공학회 1999 한국전산유체공학회지 Vol.4 No.3
A Direct simulation Monte-Carlo (DSMC) code is developed. which employs the Monte-Carlo statistical sampling technique to investigate hypersonic rarefied gas flows accompanying chemical reactions. The DSMC method is a numerical simulation technique for analyzing the Boltzmann equation by modeling a real gas flow using a representative set of molecules. Due to the limitations in computational requirements, the present method is applied to a flow around a simple two-dimensional object in exit velocity of 7.6 km/see at an altitude of 90 km. For the calculation of chemical reactions an air model with five species (O₂, N₂, O, N, NO) and 19 chemical reactions is employed. The simulated result showed various rarefaction effects in the hypersonic flow with chemical reactions.
화학반응을 수반하는 극초음속 희박류 유동의 직접모사법 개발
정찬홍(C. H. Chung),윤성준(S. J. Yoon) 한국전산유체공학회 1999 한국전산유체공학회지 Vol.4 No.3
A Direct simulation Monte-Carlo (DSMC) code is developed. which employs the Monte-Carlo statistical sampling technique to investigate hypersonic rarefied gas flows accompanying chemical reactions. The DSMC method is a numerical simulation technique for analyzing the Boltzmann equation by modeling a real gas flow using a representative set of molecules. Due to the limitations in computational requirements, the present method is applied to a flow around a simple two-dimensional object in exit velocity of 7.6 km/see at an altitude of 90 km. For the calculation of chemical reactions an air model with five species (O₂, N₂, O, N, NO) and 19 chemical reactions is employed. The simulated result showed various rarefaction effects in the hypersonic flow with chemical reactions.
압축착화 디젤엔진의 모사 EGR 시스템에 의한 소음 특성 변화 분석
박범 ( B Park ),윤성준 ( S Yoon ),박성욱 ( S Park ),박준흥 ( J Park ) 한국분무공학회 2014 한국액체미립화학회지 Vol.19 No.4
Experimental study was conducted to investigate the effect of EGR(exhaust gas recirculation) on engine noise using single cylinder combustion ignition engine. Under constant engine rotary speed of 1200 RPM, 8 mg fuel quantity was injected with 15, 18 and 21% of oxygen ratio and 1400 bar of injection pressure. Using the in-cylinder pressure data acquired by a piezoelectric transducer, the engine performance parameters were calculated. Radiated engine noise measured for 10 seconds was analyzed using spectral characteristics and sound quality metrics such as loudness, sharpness, roughness. From the obtained engine performance parameters and sound quality metrics, effect of oxygen ratio of the premixed air, start of injection timing on frequency characteristic and sound quality metrics were analyzed. Correlation analysis was conducted between MPRR(maximum pressure rise rate), RI(ringing intensity) and sound quality metrics. RI was identified as the most important factor having influence on the sound quality metrics.