2021년 OECD 농업정책평가: 중국, 미국

김충만 한국농촌경제연구원 2022 세계농업 Vol.245 No.-

채움벽 두께에 따른 철근콘크리트 조적채움벽 골조의 면내하중에 대한 유한요소해석

김충만,유은종,김민재,Kim, Chungman,Yu, Eunjong,Kim, Minjae 한국전산구조공학회 2016 한국전산구조공학회논문집 Vol.29 No.1

본 논문에서는 범용유한요소해석 프로그램인 ABAQUS를 사용하여 국내에서 사용되는 콘크리트벽돌을 조적채움벽으로 가진 철근콘크리트 골조를 대상으로 유한요소해석을 실시하였다. 해석대상은 순수골조, 채움벽의 두께가 0.5B인 골조, 두께가 1.0B인 골조의 3종류이다. 철근콘크리트 골조 및 채움벽의 재료특성은 재료시험 결과로부터 구하였으나 두께가 1.0B인 채움벽의 경우 벽돌의 쌓기방법의 차이에 의해 0.5B 두께의 실험체보다 4배 정도 증가된 인장강도를 사용하였다. 유한요소 해석결과는 실험을 통해 구한 하중-변위관계 및 변위각에 따른 균열양상을 상당히 정확하게 예측하였다. 유한요소해석 결과의 분석을 통해 조적채움벽과 골조사이의 접촉응력 및 골조의 전단력과 휨모멘트를 산정하였다. In this study, finite element analyses of masonry infilled frames using a general purpose FE program, ABAQUS, were conducted. Analysis models consisted of the bare frame, infilled frames with masonry wall thickness of 0.5B and 1.0B, respectively. The masonry walls were constructed using the concrete bricks which were generally used in Korea as infilled wall. The material properties of frames and masonry for the analysis were obtained from material tests. However, four times increased the tensile strength was used for 1.0B wall, which is seemingly due to the differences in locating the bricks. The force-displacement relation and development of crack from the FE analysis were very similar to those from the experiments. From the FEA results, contact force between the frame and masonry, distribution of shear force and bending moments in frame members were analyzed. Obtained contact stress shows a trianglur distribution, and the contact length for 0.5B speciment and 1.0B specimen were close to the value estimated using ASCE 41-06 equation and ASCE 41-13 equation, respectively. Obtained shear force and bending moment distribution seems to replicate actual behavior which originates from the contact stress and gap between the frame and masonry.

연료 물성에 따른 저독성 접촉점화 추진제의 점화 특성

김충만,강홍재,이경환,이종광 한국항공우주학회 2024 韓國航空宇宙學會誌 Vol.52 No.2

The ignition performance of hypergolic propellant is judged by ignition delay. Ignition performance could be evaluated through a drop test and a impinging jet test. The impinging get test is a method that induces a rapid chemical reaction through mixing and atomization of propellant by impinging propellant column. Physical properties of propellant affect the propellant column injected into the injector, so that the ignition performance could be changed by physical properties of propellant. In this paper, We were performed a drop test and a impinging jet test by using fuel with large differenced viscosity and vapor pressure. High-viscosity fuel had improved ignition performance with momentum, while Low-viscosity fuel with high vapor pressure had sporadic ignition phenomena and short ignition delay regardless of the momentum. 접촉점화 추진제의 점화성능은 점화지연시간으로 판단하며 이는 액적 낙하 실험과 액주 충돌 실험을 통해 평가할 수 있다. 액주 충돌 실험은 추진제 액주를 직접 충돌시킴으로써 추진제의 혼합 및 미립화를 통해 빠른 화학반응을 유도하는 실험 방법이다. 추진제의 점도나 증기압과 같은 물성은 인젝터로 분사되는 추진제 액주에 직접적인 영향을 미치기 때문에 추진제의 물성에 따라 점화성능이 변화될 수 있다. 이 연구에서는 저독성 산화제인 과산화수소를 사용하여 점도와 증기압을 기준으로 큰 차이를 갖는 연료를 선정하여 액적 낙하 실험과 액주 충돌 실험을 수행하였다. 점도가 높은 연료는 모멘텀 크기가 증가함에 따라 점화성능이 개선되었으며, 점도가 낮고 증기압이 높은 연료는 산발적인 점화현상과 모멘텀 크기에 관계없이 짧은 점화지연시간이 측정되었다.

황사와 반응하는 기체상 질산의 반응계수 연구

김충만,송철한 한국대기환경학회 2006 한국대기환경학회 학술대회논문집 Vol.- No.-

등분포 중심축 하중을 받는 단층래티스돔의 좌굴거동

김충만,유은종,나창순,Kim, Choong-Man,Yu, Eun-Jong,Rha, Chang-Soon 한국전산구조공학회 2015 한국전산구조공학회논문집 Vol.28 No.1

본 논문에서는 대공간구조에 폭넓게 사용되는 단층 래티스돔의 비선형거동에 관한 비교 연구를 수행하였다. 단층 래티스돔은 특성상 두께가 얇은 쉘구조의 거동과 유사하므로 전통적인 쉘좌굴 이론을 적용하여 내력을 산출할 수 있으며 또한 이 결과를 유한요소해석 프로그램을 이용한 수치해석의 결과와 비교, 분석하였다. 쉘좌굴 이론을 이용하여서는 래티스 돔의 전체좌굴하중과 부재좌굴하중을 산정하였으며, 유한요소해석법을 이용하여서는 고유치 해석에 의한 좌굴하중과 기하학적 비선형 해석에 의한 극한하중을 각각 산정하였다. 래티스돔의 절점은 강절점 및 핀절점으로 각각 모델링하였다. 쉘좌굴이론에 의한 좌굴내력은 전체좌굴하중과 부재좌굴하중의 작은 값으로 결정되며 이 값은 유한요소해석을 이용한 고유치 해석보다는 비선형 해석에 의한 극한하중에 보다 근사한 값을 제공하였으며 또한 좌굴하중의 형식을 예측하는데에 유용하게 활용되었다. This paper presented the nonlinear behaviors of the single-layered lattice dome, which is widely used for the long-span structure system. The behaviors were analysed through the classical shell buckling theory as the single-layered lattice dome behaves like continum thin shell due to its geometric characteristics, and finite element analysis method using the software program Nastran. Shell buckling theory provides two types of buckling loads, the global- and member buckling, and finite element analysis provides the ultimate load of geometric nonlinear analysis as well as the buckling load of Eigen value solution. Two types of models for the lattice dome were analysed, that is rigid- and pin-jointed structure. Buckling load using the shell buckling theory for each type of lattice dome, governed by the minimum value of global buckling or member buckling load, resulted better estimation than the buckling load with Eigen value analysis. And it is useful to predict the buckling pattern, that is global buckling or member buckling.

응용미학으로서의 드라마-쉴러의『빌헬름 텔 Wilhelm Tell』연구

김충만 한국외국어대학교 외국문학연구소 2002 외국문학연구 Vol.- No.10

Schiller's Wilhelm Tell: A Drama asan Applied Aesthetics

RGB와 열화상 카메라를 이용한 차량 모델 분류

김충만,이화민,홍민,남윤영 순천향대학교 부설 산업기술연구소 2016 순천향 산업기술연구소논문집 Vol.22 No.2

In this study, we propose a system for classifying vehicle models. In the proposed system, the vehicle area is separated, the headlight and grill area are classified, and then texture characteristics are extracted and used as a feature to classify the model. In addition, we used the image with features for the vehicle by thermal and visible light images. We conducted an experiment to classify the vehicle model and showed the recognition rate in experiments.

산화제 첨가물이 포함된 과산화수소의 농도 측정 방법

김충만(Chungman Kim),최은규(Eunkyu Choi),이종광(Jongkwang Lee) 한국항공우주학회 2023 한국항공우주학회 학술발표회 논문집 Vol.2023 No.4

동남참게 초기유생에 대한 생리 생태학적 연구

김충만(Choong Man KIM),정규화(Gyu Hwa CHUNG),한창희(Chang Hee HAN) 전남대학교 수산과학연구소 1994 수산과학연구소논문집 Vol.3 No.-

The present experiment was designed to obtain the adequate condition of temperature, daylength and salinity on the gonadal maturation of adult female, spawning and hatching of egg, and growth of larvae of the freshwater crab Eriocheir japonicus. Gonadal maturation was influenced by water temperature, but not daylength. GSI of female crabs more increased in experimental regime of 18℃ than that of 10℃ without regard to photoperiod conditions(12L/12D and 15L/9D). However, in both photoperiod conditions of 26℃ regime, GSIs were not changed, and vitellogenic oocytes were not observed. Spawning was considerably influenced by water temperature and salinity without regard to daylength. Vitellogenic female crabs did not spawn at 10℃ in any conditions of salinity. However, at 18℃ and 26℃, over a half of rearing female crabs spawned in condition of 30% sea water(salinity 9.6‰) and 60% sea water(salinity 19.2‰), while no spawned females appeared in freshwater condition(salinity 0.0‰). In 20% sea water(salinity 6.4‰) and less conditions, ovigerous female crabs removed eggs from the abdormal egg-chamber of one s own self before hatching out. However, all ovigerous female crabs hatched out in 40% sea water(salinity 12.8‰) and more conditions. Hatching rates were 33.3% and 83.3% in 40% sea water condition and in 60% and 80% sea water conditions, respectively. In experiment of effects on temperature on hatch out of eggs, hatching rates of eggs were 66.7% and 83.3% at 18℃ and 26℃, respectively. whereas, at 10℃ and 32℃ conditions, ovigerous females died or removed eggs before hatching out. In investigation of days required to hatch out from brooding time according to the water temperature, required days to hatch out were 28.0±1.7 days in 18℃ condition and 14.0±0.3 days in 26℃. In 20% sea water and less conditions, zoea larva died before metamorphosing to larvae of megalopha stage. However, in 40% sea water and more conditions, zoea larva metamorphosed to megalopha stage. Rates of metamorphosed zoea larva to megalopha stage were 32%, 44% and 48% in conditions of 40%, 60% and 80% sea water, respectively. Under rearing condition of 80% sea water, all of the first stage of zoea larva reared at 10℃ did not metamorphose to the second zoea stage and than died within 24 days. At 15℃, 16% of zoea larva metamorphosed to the fifth zoea stage. However, larva metamorphsing to meglaopha stage were observed from 20 and 14 days rearing at 20℃ and 26℃, respectively.

기독학교 교목의 정체성과 사역 비전

김충만(Kim, Chung-Man) 경성대학교 인문과학연구소 2017 인문학논총 Vol.43 No.-

경성대학교는 1955년 故 김길창 목사에 의해 ‘기독교 정신’으로 세워졌지만 건학 이념 보다는 대학의 성장과 발전이라는 현실적 목표를 추구해 왔다. 하지만 2014년에 경성채플과 기독교 정책과목들의 개설, 2015년에는 경성대학 교회를 설립하여 건학 이념 구현의 토대를 마련하였다. 본 논문 2-3장에서는 이러한 사명을 감당하는 교목의 정체성과 사역에 대한 문헌 연구와, 교목실 사역을 돌아보았다. 특별히 2016년 2학기 경성채플을 수강하는 692명(성별/ 남–274/39.6%, 여–398/57.5%, 무응답–20/2.9%, 종교별/ 기독교-108/15.6%, 천주교-35/5.1%, 불교-102/14.7%, 무교-440/63.6%, 기타-7/1%)을 대상으로 실시한 채플 평가와 만족도 분석을 통해 교목사역의 현재적 유의미성과 앞으로의 사역 비전을 제안한다. KyungSung University committed to ‘Christian Gospel’ was founded by the late reverend Gil Chang Kim in 1955. KyungSung has put more efforts on the highest standards of academic excellence over the last 60 years. Since 2014, several core classes focused on Christian Gospel were instituted through KS Chapel and Global KS. Celebrating 60th anniversary in 2015, KSU Church was officially dedicated to strengthen Christian Gospel and Campus Ministry. While treating in the 2nd and 3rd chapter of this paper, I introduce the office of KS Campus Chapel to answer for the identity and Christian ministry with further written studies. Particularly, I analyzed 692 students" questionaries of 2016 Second Semester (sex: male students 274 or 39.6%, female 398 or 57.5%, and none 20 or 2.9%; religion: Christians 108 or 15.6%, roman catholics 35 or 5.1%, buddhists 102 or 14.7%, atheists 440 or 63.6%, and none 7 or 1%). By this way, I want to suggest the present significance of and future tasks of Christian schools" campus chaplain ministry.