점탄성 해석을 통한 도어 웨더스트립의 영구변형 예측

문형일(Hyung-il Moon),김현영(Heon Young Kim),박준철(Joon Chul Park),민병권(Byung-Kwon Min),오정석(Jeong Seok Oh),이성훈(Seung Hoon Lee) 한국자동차공학회 2009 한국자동차공학회 학술대회 및 전시회 Vol.2009 No.11

The automotive weather strip has functions for isolating of water, dust, noise and vibration from outside. To achieve good sealing performance, weather strip should be designed to have the high contact force and wide contact area. However, these design causes excessive permanent deformation of weather strip. The causes of permanent deformation is generally explained to be the chemical material detrioration and physical variation and cyclic loading, etc. This paper introduces a numerical method to predict the permanent deformation using the time dependent viscoelastic model which is represented by Prony series in ABAQUS. Uniaxial tension and creep tests were conducted to obtain the material data. And the lab. test for the permanent deformation was accelerated during shorter time, 300 hours. The permanent deformation of weather strip were successfully predicted under the different loading conditions and different section shapes using the suggested numerical process.

마그네슘 합금 판재용 반복하중 시험기 개발

문형일(Hyung-il Moon),서오석(Oh Suk Seo),김헌영(Heon Young Kim) 대한기계학회 2011 대한기계학회 춘추학술대회 Vol.2011 No.5

Recently, application of magnesium alloy sheets to automotive industry has been rapidly increasing However, the application is still challenging due to the inferior formability, which should be overcome by proper design of forming process. Therefore, reliable experimental data to be used for the complex material models for the optimization of forming process with magnesium alloys are essential. In this paper, a new cyclic load tester, which can measure the stress-strain curves of thin sheet metals under non-monotonous condition such as tension/compression or compression/tension, was developed. Especially, the new cyclic loading tester has a direct heating system being heated up to 400℃, thus the stress-strain curves under various level of temperature can be measured. Preliminary test results are demonstrated for the commercially available magnesium alloy sheet. But more investigations are necessary to improve the current feature of the tester.

백서에서 Depulpin^®과 Formocresol에 대한 치수와 치근단 조직의 반응

문형인,김선호,황윤찬,오병주,황인남,김선헌,정선와,윤창,오원만,Moon, Hyung-In,Kim, Sun-Ho,Hwang, Yun-Chan,Oh, Byung-Ju,Hwang, In-Nam,Kim, Sun-Hun,Jeong, Sun-Wa,Youn, Chang,Oh, Won-Mann 대한치과보존학회 2002 Restorative Dentistry & Endodontics Vol.27 No.4

One fifth dilution of formocresol is usually used for pulpotomy of the primary teeth and emergency pulpotomy of the permanent teeth. However the use of formaldehyde has been subjected to criticism because it may be absorbed into the blood stream and become distributed systemically, it nay also alter the pulp tissue rendering it immunologically active, and have carcinogenic potential. Recently Depulpin$^{\circledR}$(VoCo., Germany) gains popularity as a devitalizing agent during root canal therapy in spite of high concentration of 49 % paraformaldehyde because it facilitate devitalization of pulp and make root canal therapy easier But there have been not enough publications about the reaction of pulp and periapical tissue caused by Depulpin. This study was performed to evaluate the histological changes in pulp and periapical tissue of rats after pulpotomy using formocresol and Depulpin and to elucidate the toxic effects of these agents. Thirty six Sprague-Dawley rats were anesthetized by intraperitoneal injection of ketamine Maxillary first molar teeth were used for pulpotomy with formocresol and Depulpin. Rats were sacrificed after 2 days, 4 days, 1 week, 2 weeks, 3 weeks and 4 weeks respectively. Specimens were histologically observed by light microscope changes in pulp and periapical tissue. The obtained results were as follows. 1. Formocresol group A zone of fixed tissue. in which odontoblasts could clearly be defined, was present directly underneath the pulpotomy dressing in almost all teeth of this group. This was followed by an area of necrotic tissue which resembled dried out fibrous tissue with no cellular detail except some pyknotic nuclei. In the specimens of after 2 days, 4 days, 1 week, 2 weeks in which vital tissue was present, it was separated from the fibrous area by a zone of inflammation. In the specimens of after 3 weeks and after 4 weeks, inflammatory infiltrate was in the periodontal ligament adjacent to the apical foramina of the teeth. 2. Depulpin$^{\circledR}$ group The area of necrotic tissue which had no cells and fibers, was present adjacent to the dressing. This was followed by dried out fibrous tissue with no cellular details except some pyknotic nuclei, A short stump of vital pulp with odontoblasts was present at the end of the canal after 2 days. Inflammatory infiltrate was in the periodontal ligament after 4 days and after 1week. Severe root resolution and necrosis of periapical tissue opposite the root resorption site were defined after 2 weeks and after 3 weeks. Periapical lesion which consist of necrotic tissue surrounded by a fibrous connective wall, was found after 4 weeks. The results indicated that Depulpin can cause more adverse reaction to the dental pulp and periapical tissue than formocresol, and further studies are needed for its clinical use with safety.

자동차용 웨더스트립의 변형 해석 및 형상 최적화

문형일(Hyung-il Moon),민병권(Byung-Kwon Min),오정석(Jeong Seok Oh),박준철(Joon Chul Park),이성훈(Seung Hoon Lee),김헌영(Heon Young Kim) 한국자동차공학회 2009 한국자동차공학회 부문종합 학술대회 Vol.2009 No.4

A weatherstrip is a mechanical element, which has the function of isolating dust, rain, noise and vibration from outside of a car. The basic requirement of door seal is a good sealing and minimizing door closing effort. But better sealing performance requires both higher reaction force and wider contact area, while better door-closing performance requires just the opposite. This paper was introduced the optimization process of automotive door seal using response surface method, downhill simplex method, and a three dimensional door closing analysis using explicit code for more realistic solution. In addition, we showed the material test method of door seal for reliability analysis result.

자동차용 도어 닫힘 성능 예측

문형일(Hyung-il Moon),민병권(Byung-Kwon Min),오정석(Jeong Seok Oh),박준철(Joon Suk Park),이성훈(Seung Hoon Lee),김헌영(Heon Young Kim) 한국자동차공학회 2008 한국자동차공학회 춘 추계 학술대회 논문집 Vol.- No.-

오동나무꽃의 항암성분

오좌섭,지옥표,문형인,Oh, Joa-Sub,Zee, Ok-Pyo,Moon, Hyung-In 한국생약학회 2000 생약학회지 Vol.31 No.4

In search for plant-derived cytotoxic compounds, it was found that the $CHCl_3$ and EtOAC extracts obtained from the flowers of Paulownia coreana Uyeki (Scrophulariaceae) exhibited significant cytotoxic activity against human tumor cell lines, A549, SK-OV-3, SK-MEL-2, XF498, and HCT15. Activity-guided fractionation on the basis of the inhibitory activity against the growth of human tumor cell lines, in vitro, and repeated column chromatography afforded several cytotoxic compounds from P. coreana. The structures and stereochemistry of these compounds were established, on the basis of analysis of spectra including IR, UV, EI-MS, $^{1}H-NMR,\;^{13}C-NMR$ and some chemical transformations, as Compound PCCl $(2-hydroxy-4(15),11(13)-eudesmadien-8{\beta},12-olide)$, Compound $PCC2(2,3-dihydro-4-hydroxy-1(15),11(13)-xanthadien-8{\beta},12-olide)$, Compound PCE1 (chrysophanol), Compound PCE2 (emodin), Compound PCE3 (physcion). Cytotoxic activity of compounds obtained from P. coreana. on five tumor cells lines was evaluated by procedure of SRB methods.

한국 옛사람과 현대사람 치아의 체질인류학적 특징

허경석(Kyung-Seok Hu),오현주(Hyun Joo Oh),문형순(Hyung Soon Moon),강민규(Min Kyu Kang),최종훈(Jong Hoon Choi),김기덕(Kee Deog Kim),백두진(Doo Jin Paik),고기석(Ki Seok Koh),한승호(Seung Ho Han),정락희(Rak Hee Chung),박선주(Sun Joo Par 대한체질인류학회 1999 해부·생물인류학 (Anat Biol Anthropol) Vol.12 No.2

치아는 씹기와 발음 뿐만 아니라, 미용적인 측면에서도 매우 중요한 역할을 담당한다. 또한 치아의 계측적, 비계측적 특징은 종족간 인류학적 비교나 고고학적 의의 그라고 개인의 신원 확인에 이용될 수 있으므로 체질인류학적, 고고학적 그리고 법치학적인 중요성을 갖는다. 그러나 이에 대한 연구가 국내에서는 활발히 이루 어지지 않아 한국사람 치아의 제정인류학적 특성에 관한 포괄적인 자료는 찾아보기 힘들다. 이에 연구자들은 가야, 고려 및 조선인의 치아 1085 (71 구 ) 개와 한국 현대사람 남녀의 치아 1397 (96 구 ) 개를 대상으로 각 치아마다 5 가지 항목을 계측하고,9 개 항목의 비계측 특정을 조사하였다. 이러한 치아 계측치와 비계측적 특정이 옛 사람과 현대 사람에서 나타나는 차이 점을 비교하였다. 한국 옛사람과 현대사랍 치아의 계측치들을 비교해 보았을 때, 치아의 얼굴쪽혀쪽 너비는 옛사람과 현대사람에서 계측치의 차이가 나타나지 않은 반면, 치아의 안쪽먼쪽 너비 항목에서는 약간의 차이를 나타내었다. 한국사람 치아의 비계측 특정을 조사해 본 결과, 위턱 안쪽앞니에서 삽모양앞니의 출현율은 옛사람에서 96.4%, 현대사람에서 94.2% 를 보였으며, 위턱 가쪽앞니에서 삽모양앞니는 옛사람 93.1%, 현대사람 90.6% 의 빈 도로 옛사람에서 삽모양앞니의 출현빈도가 더 높았다. 아래턱 둘째작은어금니의 혀쪽 교두의 수를 비교한 결과, 옛사람에서는 l 개 (48.0%) 또는 2 개 (52.0%) 의 혀쪽 교두만야 관찰되었으나, 현대사람의 아래턱 둘째작은어금니는 1 개 (52.3%),2 개 (46.7%) 또는 3 개 (1.0%) 의 혀쪽 교두를 가지고 있였다. 현대사람 위턱 첫째작은어금니에서 테라결절은 치아의 안쪽면에 나타난 경우가 53.7% 로 가장 많았으나, 위턱 둘째작은어금니에서는 결절이 나타나 지 않은 경우가 48.7% 호 가장 많았다. 반면에 옛사람은 현대사랍보다 더 높은 빈도의 테라결절 발현 양상을 보 였다. 위턱 첫째큰어금니에서 카라벨리결절의 출현빈도는 옛사람에서 18.4%, 현대사랑에서 36.2% 로 현대사람에서 더 많이 나타나는 경향을 보였다. 교합면 고랑모양은 위턱 첫째큰어금니에서 ‘4-’ 모양이 가장 많았으나 ( 옛 사람 94.3%, 현대사람 94.3%), 위택 둘째큰어금니에서는 ‘+4’모양이 가장 많이 나타났다 ( 옛사랍 40.5%, 현대 사람 76.5%) 옛사랍 , 현대사람 모두에서 아래턱 첫째큰어금니 교합변 고랑의 형태는 ‘Y5’모양이 가장 많았으며, 아래턱 둘째큰애금니에서는 ‘+4’모양이 가장 많이 나타났다.

자동차용 웨더스트립의 영구변형 예측

박준철(Joon Chul Park),민병권(Byung-Kwon Min),오정석(Jeong Seok Oh),문형일(Hyung-il Moon),김헌영(Heon Young Kim) 한국자동차공학회 2010 한국 자동차공학회논문집 Vol.18 No.4

월상골 주위 탈구 및 골절탈구

김용진(Yong-Jin Kim),오문형(Moon-Hyung Oh),서정탁(Jeung-Tak Suh),유총일(Chong-Il Yoo) 대한정형외과학회 1995 대한정형외과학회지 Vol.30 No.3

합리적인 하천수 관리체계 구축을 위한 자료기반 방류량 예측모형 개발

유형주,이승오,최서혜,박문형,Yoo, Hyung Ju,Lee, Seung Oh,Choi, Seo Hye,Park, Moon Hyung 한국방재안전학회 2020 한국방재안전학회 논문집 Vol.13 No.4

일반적으로 물수지 분석 시 공급에 해당되는 회귀수량의 경우 용수별 회귀율을 일률적으로 정하여 산정하는 방법을 채택하고 있어 정확한 가용유량을 산정하지 못하는 한계를 갖고 있다. 이에 본 연구에서는 회귀수 중 하·폐수에 초점을 두었고 인공신경망 등의 기계학습 모형을 적용하여 하수종말처리장의 방류량 예측 모형을 개발하였다. 시계열 자료예측 시 사용되는 주요 기계학습 모형인 LSTM (Long Short-Term Memory), GRU (Gated Recurrent Units), SVR (Support Vector Regression)모형을 적용하였으며 관측 값과 예측 값을 비교하는 오차지표를 통하여 방류량 예측의 최적의 모형을 선정하였다. 모형 적용 결과, GRU 모형의 평균제곱근 오차(Root Mean Square Error, RMSE)는 LSTM 모형과 SVR 모형보다 작으며 Nash-Sutcliffe 계수(NSE)는 LSTM 모형과 SVR 모형보다 큰 것을 확인하였고, 이를 근거로 하수종말처리장의 방류량 예측에 최적모형은 GRU 모형이라고 판단하였다. 다만, 극값에서는 예측 값이 과소 및 과대 산정되는 경향을 보여 추후 예측 정확도 향상을 위해서는 극한사상에 대한 추가자료 구축 및 입력 자료의 최소시간단위를 축소하는 것이 필요할 것으로 판단되었다. 또한, 예측하고자 하는 대상지의 용수이용량을 검토하고 계절적 영향을 반영할 수 있는 추가인자를 고려하게 되면 기후변동성에 대비하여 정확한 방류량 예측이 가능하며 예측 결과를 토대로 종합적인 하천수 사용관리 및 물이용 계획 수립을 위한 기초자료로 활용될 수 있을 것으로 기대된다. In most cases of the water balance analysis, the return flow ratio for each water supply was uniformly determined and applied, so it has been contained a problem that the volume of available water would be incorrectly calculated. Therefore, sewage and wastewater among the return water were focused in this study and the data-driven model was developed to forecast the outflow from the sewage treatment plant. The forecasting results of LSTM (Long Short-Term Memory), GRU (Gated Recurrent Units), and SVR (Support Vector Regression) models, which are mainly used for forecasting the time series data in most fields, were compared with the observed data to determine the optimal model parameters for forecasting outflow. As a result of applying the model, the root mean square error (RMSE) of the GRU model was smaller than those of the LSTM and SVR models, and the Nash-Sutcliffe coefficient (NSE) was higher than those of others. Thus, it was judged that the GRU model could be the optimal model for forecasting the outflow in sewage treatment plants. However, the forecasting outflow tends to be underestimated and overestimated in extreme sections. Therefore, the additional data for extreme events and reducing the minimum time unit of input data were necessary to enhance the accuracy of forecasting. If the water use of the target site was reviewed and the additional parameters that could reflect seasonal effects were considered, more accurate outflow could be forecasted to be ready for climate variability in near future. And it is expected to use as fundamental resources for establishing a reasonable river water management system based on the forecasting results.