Comparative anatomical characteristics of cardiac valves in animals

남창훈,Hak Young Kim,Chun-Mei Lin,연정민 충북대학교 동물의학연구소 2014 Journal of Biomedical and Translational Research Vol.15 No.1

Although various animals have been used as models of cardiac valvular diseases in humans, the structural characteristics of cardiac valves in animals remain un- clear. In this study, we investigated cardiac valves in representative animal models for the purpose of com- parative anatomy. Adult hearts from three dogs, four goats, six rabbits, and six fowls were fixed with 10% neutral-buffered formalin and analyzed gross-anatom- ically. Cardiac appearance was spherical or oval in dogs, goats, and rabbits, whereas it had a long conical shape in fowls. Left atrioventricular (AV) valve was composed of membranous septal and parietal cusps connected to two papillary muscles in all animals. The right AV valve was composed of membranous septal, parietal, and angular cusps with three papil- lary muscles in dogs and goats, membranous septal and parietal cusps attached to four papillary muscles in rabbits, and a single muscular plate without any papillary muscles and chorda tendinae in fowls. Aortic valves with thin membranous right, left, and septal semilunar cusps in dogs, goats, and rabbits had a thick membrane with a bended free border in fowls. Pul- monary valve (PV) with membranous right, left, and intermediate semilunar cusps made a large central hole by being closely attached to the surrounding wall in dogs, goats, and rabbits, whereas it protruded into half of the lumen as a thick membrane in fowls. The membranous cusp of the PV was composed of several layers in dogs and goats but was a single layer in rab- bits and fowls. These findings indicate that even if animals have two completely separated atria and ventricles each, car- diac valves have species-specific morphological char- acteristics, especially between mammals and fowls.

An Introduction to the Long-Lasting Dispute on Empirical Methods of Measuring Local Expenditure Needs

Nam, Chang Woon 韓獨經商學會 1997 經商論叢 Vol.15 No.1

금속재료의 동적항복응력 결정을 위한 봉충격시험법

민옥기,이정민,남창훈,황재준 대한기계학회 1993 대한기계학회논문집 Vol.17 No.1

본 연구에서는 Gillis 이론의 이와같은 단점을 보완하기 위하여 Gillis에 의 하여 제시된 수정운동량 보존법칙과 Hawkyard에 의하여 제시된 에너지보존법칙을 일반 화한 수정에너지보존법칙을 동시에 고려하여 재료의 동적항복응력을 결정할 수 있으며, 봉충격시험편의 충돌완료 후의 변형형상간의 관계를 고려할 수 있는 이론을 제시하였 다. 또한 기존의 실험결과로부터 제시된 이론의 타당성을 분석하였으며, 시험편의 변형형상의 측정오차가 동적항복응력의 결정에 미치는 영향을 분석하였다. 한편 압 축공기를 이용한 시험편 가속정치에 의하여 봉충격시험을 수행하여 괘삭황동(free -cutting brass)의 고변형률속도하에서의 변형특성과 동적항복응력을 결정하였다. A new theory based on the modified momentum and energy conservation has been proposed in order to overcome the drawbacks included in previous theories which are used for the determination of dynamic yield stresses and the investigation of dynamic behavior of metals. Then the improvements suggested by the new theory have been manifested through the analysis of the error included in the measurement of deformed length and through the comparison between the new theory, existing theories, and experimental results performed by previous workers. Meanwhile rod impact test has been performed which uses a compressed- air system for the acceleration of flat-ended cylindrical free-cutting brass rods. From the geomtrical measurements of deformed length, the dynamic yield stress of free-cutting brass has determined.

이공계 대학생의 사회적 책임감 함양을 위한 ENACT 모형의 개발과 교육적 함의

이현주,최유현,남창훈,옥승용,심성옥,황요한,김가형 한국공학교육학회 2020 공학교육연구 Vol.23 No.6

This study aims to introduce the ENACT model, which is a systematic teaching-learning model for cultivating social responsibility of science and engineering college students, and to discuss its educational implications. For the development of the ENACT model, we conducted extensive literature reviews on RRI, STEM education, and science and technology studies (STS). In addition, we examined exemplary overseas education programs emphasizing social responsibility of scientists/engineers and citizens. The ENACT model consists of five steps; 1) Engage in SSIs, 2) Navigate SSIs, 3) Anticipate consequences, 4) Conduct scientific and engineering practice, and 5) Take action. This model links Socioscientific Issues (SSI) education with engineering education, dividing the major elements of social responsibility education for scientists and engineers into the dimensions of epistemology and praxis, and reflected them in the model. This effort enables science and engineering college students to pursue more responsible and sustainable development by carrying out the responsible problem-solving process based on an understanding of the nature of science and technology. We plan to implement ENACT model based programs for science and engineering college students and to examine the effects.

다양한 노면 조건에서의 능동 긴급 제동 시스템(AEBS) 성능 해석 시뮬레이션

손민혁(Minhyuk Son),남창훈(Changhoon Nam) 한국자동차공학회 2012 한국자동차공학회 학술대회 및 전시회 Vol.2012 No.11

This paper presents the use of software tools that together provide the ability to cover critical aspects of active safety system design and performance analysis simulation. One of the software tools (PreScan) focuses on the design of the sensing and control systems, as well as the evaluation for a wide range of traffic and weather scenarios. Another software tool (CarSim) takes care of the detailed vehicle dynamics and has the function for external tire model and road profiles. For detailed the tireroad contact patch and tire forces, a Short Wavelength Intermediate Frequency Tyre (SWIFT) model has considered. A road profile model can generate by OpenCRG easily and coupled with the tire models in the CarSim. By means of an application example of an Active Emergency Braking System (AEBS) under rough road conditions, the combined use of those software tools to design and evaluate the performance of active safety system is demonstrated.

고 변형률 속도하에서의 폴리카아보네이트의 동적 물성 결정을 위한 봉 충격 시험법에 있어서 종횡비의 효과

민옥기(Oak Key Min),남창훈(Chang Hoon Nam),이정민(Jeong Min Lee) 한국고분자학회 1992 폴리머 Vol.16 No.4

Bong-Han Corpuscles as Possible Stem Cell Niches on the Organ-Surfaces

김민수,홍주영,홍수,이병천,남창훈,우희종,강대인,소광섭,Kim, Min-Su,Hong, Ju-Young,Hong, Su,Lee, Byung-Cheon,Nam, Chang-Hoon,Woo, Hee-Jong,Kang, Dae-In,Soh, Kwang-Sup KOREAN PHARMACOPUNCTURE INSTITUTE 2008 Journal of pharmacopuncture Vol.11 No.1

목적 : 봉한소체가 성체줄기세포의 원천이며, 봉한관이 줄기세포 수송로일 가능성을 확인함. 방법 : 쥐의 내부 장기표면에서 봉한소체와 봉한관을 채취했다. 다양한 줄기세포 표지항체를 써서 면역조직학적 분석을 했다. 결과 : mesenchymal 줄기세포에 관한 Integrin ${\beta}1$, Collagen type 1, Fibronectin의 강한 발현을 확인했다. CD54는 발현되지 않았다. 조혈줄기세포에 관련하여 Thy 1의 발현이 있었다. 결론 : 골수조직과 유사하게 mesenchymal과 조혈줄기세포의 표지가 BHC에서 확인되었고, 봉한관에서는 vWF가 발현되어 줄기세포 수송로 가능성을 확인했다. Objectives : Showing that Bong-Han corpuscles(BHC) are suppliers of the stem cells in adulthood, and the Bong-Han ducts(BHD) are transportation routes of stem cells. Methods : BHC and BHD were obtained from the internal organ-surfaces of rats. The sliced BHC and BHD were immunostained with various stem cell markers. Extracellular matrices were also analyzed by immunohistochemistry. Result : The presence of mesenchymal stem cells was confirmed by the expression of Integrin beta 1, Collagen type 1 and Fibronectin. But CD54 was not expressed. The hematopoietic stem cell marker, Thy 1 was strongly expressed. BHDs showed Collagen type 1, Fibronectin, and vWF expression. Conclusion : Both hematopoietic and mesenchymal stem cell markers were expressed strongly in BHC similarly as in bone marrow. An endothelial cell marker(vWF) demonstrated the possibility of the stem cell transportation routes of BHD.

제어기 개발에서의 차량용 통신 연속 테스트 환경 구현

박시우(Siwoo Park),유창열(Changyeol Yoo),남창훈(Changhoon Nam) 한국자동차공학회 2024 한국자동차공학회 부문종합 학술대회 Vol.2024 No.6

EuroNCAP 정면충돌 시험의 신뢰성 분석

김요셉(Joseph Kim),범현균(Hyenkyun Beom),권성은(Sungeun Kwon),남창훈(Changhoon Nam) 한국자동차공학회 2009 한국자동차공학회 부문종합 학술대회 Vol.2009 No.4

Numerical simulation has played an important role in the vehicle development. Especially vehicle crash numerical simulations have been indispensable more and more in order to save the developing time and cost. However numerical simulation are usually deterministic. Crash tests results have scatter due to many variables such as manufactory condition of vehicle, test condition, margin for test procedures, slight deference of restraint system performance and so on. In order to consider these varieties under test situation, CAE based stochastic analysis has performed. In this paper, stochastic numerical simulations are carried out using MADYMO and ADVISER to investigate the variance of frontal EuroNCAP test results. In addition, influence of parameters on the result of frontal EuroNCAP tests are analyzed using stochastic post-processing tools. The results showed that EuroNCAP point varied from 9.7 to 11.1 according to calculation conditions and these value of bandwidth was 12 % of maximum point. In two cases, head bottoming out occurred.

과학기술자의 사회적 책임에 대한 이공계 대학생의 인식 탐색

고연주(Ko, Yeonjoo),심성옥(Shim, Sungok Serena),황요한(Hwang, Yohan),최유현(Choi, Yuhyun),옥승용(Ok, Seung-Yong),남창훈(Nam, Chang-Hoon),이현주(Lee, Hyunju) 한국공학교육학회 2022 공학교육연구 Vol.25 No.2

This study aimed to investigate the views of STEM college students on the social responsibility of scientists and engineers. A total of 660 students in STEM majors at several Korean universities participated in the study. We assessed social responsibility among college students in STEM majors using the VSRoSE scale, which taps into eight different domains of social responsibility: Concern for human welfare and safety (HUMAN), Concern for environmental sustainability (ENVIR), Consideration of societal risks and consequences (CONSEQ), Consideration of societal risks and consequences (CONSEQ), Consideration of societal needs and demands (NEEDS), Pursuit of the common good (COMGOOD), Civic engagement and services (CIVIC), Communication with the public (COMMU), and Participation in policy decision-making (POLICY). Group differences in social responsibility by gender, majors, and years in school were examined. Mean scores in HUMAN, ENVIR, and CONSEQ were relatively higher than those in NEEDS, COMGOOD, CIVIC, COMMU, and POLICY. Cluster analysis identified five different groups with similar patterns of social responsibility scores. In addition to two groups with overall high and low scores across all eight factors of VSRoSE, three additional groups with different combinations of high and low scores in different factors were identified. The results indicated that students with low social responsibility are not homogeneous and these heterogeneous sub-groups of students will need tailored interventions highlighting different factors of social responsibility that they lack. Pedagogical implications of social responsibility for education were discussed.