힌지모델을 이용한 강 거더 교량의 비선형 지진해석

이도형,김용일,이두호,전정문,Lee, Do Hyung,Kim, Yong Il,Lee, Doo Ho,Jeon, Jeong Moon 한국강구조학회 2009 韓國鋼構造學會 論文集 Vol.21 No.4

In the present study, nonlinear earthquake analysis was carried out for a steel girder bridge that had been damaged by the 1995 Kobe earthquake. For such analysis, the use of hysteretic models describing flexure-axial and shear-axial interaction was suggested. The models were incorporated into a structural analysis program in terms of the joint elements representing hinge models, and then a simplified analysis scheme using the hinge models was employed for bridge piers. The analytical predictions of the flexure-axial interactive hinge model show a good correlation with those of the detailed fiber element model. In addition, the analytical predictions of the flexure-shear-axial interactive hinge model enable a displacement component to be separately captured. It is thus recognized that the present study can be a useful scheme for the healthy evaluation of the global displacement performance of piers subjected to earthquake excitation. 본 연구에서는 1995년 고베 지진에 의해 손상을 입은 강 거더 교량에 대해 비선형 지진해석을 수행하였다. 해석수행을 위해 휨-축력 및 휨-전단-축력간의 상호작용을 모사할 수 있는 이력모델을 제안하였다. 제안된 이력모델은 힌지모델 형태로 구조해석 프로그램에 조인트 요소로 연결한 후, 힌지모델 사용한 간편한 해석기법을 교량 교각에 적용하였다. 휨-축력 상호작용을 고려한 해석결과는 상세한 화이버 요소 해석결과와 비교하였고, 좋은 상관관계를 나타내었다. 또한, 휨-축력-전단 상호작용을 고려한 해석결과는 지진하중을 받는 교각의 변위 요소별 검토가 가능하여 교각의 전체 변위성능 분석에 유용하게 사용할 수 있을 것으로 판단된다.

하절기 고온스트레스에 따른 생산성 저하 방지를 위한 착유우 사양관리(상)

이도형,Lee, Do-Hyeong 한국단미사료협회 2004 사료산업 Vol.2 No.6

푸르른 실록의 5월이 지나 6월에 접어들면 우리나라의 경우 더위의 시작과 장마가 찾아오는 시기로 접어든다. 덥고 습윤한 환경은 우리 인간 뿐만 아니라 가축에게도 스트레스를 주고 생산성 저하를 유발시키고 경제적인 손실을 준다. 특히 착유우에 있어 덥고 다습한 환경은 체유지와 유생산을 위한 영양소의 섭취를 저해시키는 요인으로 작용하고 있다. (중략)

홀스타인 착유우에서 중성세제불용섬유소의 수준과 조사료유래 중성세제불용섬유소의 수준이 사료섭취량 및 유생산성에 미치는 영향

이도형,권찬호,김은중,김현진,김겸헌,김수기,Lee, Do Hyung,Kwon, Chan Ho,Kim, Eun Joong,Kim, Hyun-Jin,Kim, Gyeom-Heon,Kim, Soo-Ki 한국초지조사료학회 2013 한국초지조사료학회지 Vol.33 No.4

본 연구는 사료 내 총NDF 수준과 조사료에서 기인된 NDF 수준(fNDF)이 착유우에서의 영양소 섭취량과 유생산성에 미치는 영향을 평가하기 위하여 실시하였다. 분만우 36두를 대상으로 6개의 처리구를 나누어 $2{\times}3$ 요인실험으로 설계를 하였고, 각 처리구별 사료는 건물기준 NDF 38%에 1) fNDF 18%, 2) fNDF 15%, 3) fNDF 12% 와 건물기준 NDF 34%에 4) fNDF 18%, 5) fNDF 15%, 6) fNDF 12%로 구분하여 분만 후 3주부터 20주까지 급여하였으며 결과의 처리는 분만 4주부터 영양소 섭취량 및 산유성적을 분석하였다. 사료 내 총 NDF 함량과 fNDF 함량이 감소함에 따라 건물섭취량, NEl 섭취량 그리고 비구조탄수화물 섭취량이 유의적으로(p<0.01) 증가하였고, 통계적인 유의성은 없었으나 유생산량 또한 다소 증가하는 경향이었으며 유지방율은 감소하였다(p<0.01). 건물섭취량의 증가에 따른 NEl 섭취량의 증가가 유발되었고, NDF 섭취량은 감소하였음에도 불구하고 NDF 함량이 낮은 처리구와 높은 처리구간의 비교에서 유지방율에 대한 유의적인 차이를 나타내지는 않았다. 총 NDF와 조사료유래 NDF의 사료 내 함량변화는 유단백질율과 무지유고형분 함량에는 영향을 미치지 않았지만, 유단백질 함량과 무지유고형분 생산량에 있어서는 유량 증가에 의한 영향으로 증가하는 경향을 나타내었다. 조사료유래 NDF 섭취량과 유지방율 간의 상관관계는 저수준 NDF 함량에서 고수준 NDF 함량보다 높게 나타났으며 유량과 영양소 섭취량간의 상관관계 또한 저수준의 NDF 처리구에서 고수준 처리구보다 높게 나타났다. This study was conducted to investigate the effect of total neutral detergent fiber (NDF) and forage-derived NDF (fNDF) on nutrient intake and milk production in Holstein dairy cows. Thirty-six Holstein dairy cows at weeks 4 to 20 of lactation were included in this study. The cows were arranged in a randomized complete block design and assigned to one of six diets: 1) 38% NDF with 18% fNDF (HN-HF); 2) 38% NDF with 15% fNDF (HN-MF); 3) 38% with 12% fNDF (HN-LF); 4) 34% NDF with 18% fNDF (LN-HF); 5) 34% NDF with 15% fNDF (LN-MF); and 6) 34% with 12% fNDF (LN-LF). The cows were fed a total mixed ration twice daily (07:00 and 18:00 h) and given ad libitum access to feed and water throughout the experiment. Data on the intake of nutrients (DM, NEl, CP, NDF, fNDF, NFC), milk yield, composition, fat-corrected milk (FCM), fat and protein corrected milk (FPCM), and energy corrected milk (ECM) were analyzed. Lower dietary concentrations of total NDF or fNDF resulted in an increase in DM, NEl, and NFC intake (p<0.01), milk yield (p<0.05) and a lower milk fat concentration (p<0.01). The LN treatment showed no significant differences in milk fat concentration compared to the HN however, further reduction in fNDF decreased milk fat content (p<0.01). The lowest level of milk fat was observed in the LN-LF diet group. Changes in the dietary concentrations of NDF or fNDF did not affect the concentrations of milk protein or SNF (solid not fat), although the yield of milk protein and SNF increased with higher milk yield (p<0.01). The level of fNDF influenced the level of FCM (p=0.07), as well as FPCM and ECM yield (p<0.05). A highly positive correlation between fNDF intake and milk fat concentration was observed in animals with low NDF compared to those offered high NDF. A strong correlation was also observed between milk yield and low NDF intake compared to high NDF intake.

철근콘크리트 구조물의 성능기반 평가방법

이도형,Lee, Do-Hyung 배재대학교 공학연구소 2006 공학논문집 Vol.8 No.1

In order to evaluate the seismic performance of a reinforced concrete building structure, four different analyses are carried out. Firstly, conventional pushover analysis with code-specified inverted triangular load pattern is conducted. Secondly, the pushover analysis with uniform load pattern is performed. Thirdly, adaptive pushover analyses with spectral amplification for both EC 8 artificial and Northridge earthquake are carried out. Lastly, Incremental dynamic analyses under a number of scaled PGA for both EC 8 artificial and Northridge earthquake record are performed. Comparative studies demonstrate that the adaptive pushover analysis may be able to explain the response characteristics that conventional pushover analysis with fixed load distribution fails to capture.

Langmuir 미끄럼 경계조건을 이용한 미소 박리유동의 예측

이도형,맹주성,최형일,나욱상,Lee, Do-Hyung,Meang, Joo-Sung,Choi, Hyung-Il,Na, Wook-Sang 대한기계학회 2003 大韓機械學會論文集B Vol.27 No.8

The current study analyzes Langmuir slip boundary condition theoretically and it is tested in practical numerical analysis for separation-associated flow. Slip phenomenon at the channel wall is properly implemented by various numerical slip boundary conditions including Langmuir slip model. Compressible backward-facing step flow is compared to other analysis results with the purpose of diatomic gas Langmuir slip model validation. The numerical solutions of pressure and velocity distributions where separation occurs are in good agreement with other numerical results. Numerical analysis is conducted for Reynolds number from 10 to 60 for a prediction of separation at T-shaped micro manifold. Reattachment length of flows shows nonlinear distribution at the wall of side branch. The Langmuir slip model predicts fairly the physics in terms of slip effect and separation.

수평스티프너를 이용한 철골 기둥-보 약축접합부 상세 개발에 관한 연구

이도형,함정태,김성배,김영호,김상섭,Lee, Do Hyung,Ham, Jeong Tae,Kim, Sung Bae,Kim, Young Ho,Kim, Sang Seup 한국강구조학회 2004 韓國鋼構造學會 論文集 Vol.16 No.5

The strong beam-to-column axis connections in steel structures have been studied for a long time to develop the strength and resistance of the connections. There have been very few studies, however, related to weak axis connections. Domestically, the bracket-type connection is commonly used in weak axis connections to elevate the efficiency of the constructions when the steel structures are constructed. The bracket-type connection detail has been applied moderately to weak axis connections. Therefore, the bracket-type connection in weak axis connections might be brittle and over-designed. The results of this study showed that the welding on the web of the column and the beam was unnecessary. In addition, this study confirmed that the new weak axis connection proposed in this study was superior to the previous connection in terms of strength and ductility. 철골 기둥-보 강축 접합부에 대한 연구는 그 동안 국내외에서 오랜 기간 연구가 진행되어 내진성능 및 접합부의 강도를 개선시킬 수 있는 많은 접합 형식이 개발되어 사용 중에 있으나, 약축 접합 형식에 대한 연구는 거의 없는 실정이다. 또한 현재 국내에서는 시공성을 고려하여 기존의 브라켓형식 용접 접합부를 선호하고 있으나, 용접량이 많아 취성적인 거동이 우려되며 과대 설계된 경향이 있다. 본 연구의 실험 결과에서 기존 브라켓 형식 용접접합은 용접량이 과도한 것으로 나타났으며, 기둥 웨브와 보의 웨브의 용접은 불필요한 것으로 판단된다. 그리고 본 연구에서 제안한 새로운 기둥-보 약축 접합형식들에 대한 실험 결과에서 기존 브라켓형식 용접접합보다 우수한 내력 및 연성을 보유하여 구조적으로 안전함을 확인할 수 있었다.

사매가 대장암 세포에 미치는 영향

이도형,김진성,윤상협,류기원,류봉하,Lee, Do-Hyoung,Kim, Jin-Sung,Yoon, Sang-Hyub,Ryu, Ki-Won,Ryu, Bong-Ha 대한한방내과학회 2005 大韓韓方內科學會誌 Vol.26 No.2

Objectives: The aim is to identify any anti-tumor effects of Duchesnea indica(Andr.) Focke on colon cancer cells. Materials & Methods: Colo201 human adenocarcinoma cells were obtained from American Type Culture Collection. The boiled extract of Duchesnea indica(Andr.) Focke was added (10 and 20 microliters) to cultures and observed at 0, 6, and 12 hours, and at 12-hour intervals thereafter. Morphological changes in colon cancer cells were observed through an inverted microscope, Destruction of colon cancer cells was measured through Trypan blue exclusion testing. Suppression of the viability of colon cancer cells were measured via MTT assay. Anti-cancer mechanisms in the cell cycle of colon cancer cells were analysed via flow cytometry. Results: After introduction of Duchesnea indica(Andr.) Focke to cultures several changes were seen. Significant atrophy of the nucleus and cytoplasm of colon cancer cells was observed, indicating cell injury. Destruction of colon cancer cells was observed in direct proportion to dosage and duration. Suppression of viability of colon cancer cells for each test group was greater than that of the control group increasingly over time(36h, 48h, 60h, 72h), which was statistical significant (p<0.05). Cell numbers of the mitosis phase of the colon cancer cell cycle reduced. Conclusions: Statistcally significant anti-tumor effects of Duchesnea indica(Andr.) Focke were observed in this in vitro experiment. Results support a role for Duchesnea indica(Andr.) Focke in treatment of colon cancer. though it will required progressive research to develop a practical treatment.

전단이 RC 교각의 지진성능 및 파괴모드에 미치는 영향

이도형,Lee, Do-Hyeong 배재대학교 공학연구소 2004 공학논문집 Vol.6 No.1

본 연구에서는 지진하중을 받는 철근콘크리트 교각의 지진성능 및 파괴모드에 전단이 미치는 영향을 조사하였다. 본 연구에서 개발된 전단-축력간의 상호거동 이력응답 모델의 검증을 위하여 철근콘크리트 기둥 실험에 대한 비교해석을 수행하였다. 비교결과, 예측된 해석치는 전단에 관한 하중-변위 이력응답에 있어서 실험결과와 좋은 상관관계를 보여주었다. 아울러, 본 연구에서 개발된 모델을 이용하여 고베 지진에 의해서 손상된 철근콘크리트 교량의 비선형 시간이력 해석을 수행하였다. 교각의 변위응답에 관한 분석결과, 축력의 변화를 고려한 전단의 영향으로 인하여 최대변위가 상당히 증가하였고, 전반적인 교각 강성의 감소와 함께 진동주기의 증가를 유발한다는 것을 알 수 있었다. 따라서 전단과 축력의 영향을 동시에 고려한 응답에 철근콘크리트 교각의 지진손상 평가에 관해서 보다 나은 설명을 제공할 수 있을 것으로 사료된다. In this paper, influence of shear on the seismic performance and failure mode of reinforced concrete piers subjected to earthquake loading is investigated. Comparative study has been carried out for reinforced concrete column tests to verify the shear-axial interaction model presented in this paper. Comparison shows that predicted shear hysteretic response agrees well with the test results. Also conducted is a nonlinear time-history analysis of a reinforced concrete bridge damaged by the Kobe earthquake using the current development. Displacement response for piers reveals that maximum displacement is considerably increased due to the effect of shear coupled with axial force variation, which leads to overall stiffness degradation and period elongation. It is therefore concluded that the response considering both shear and axial force gives better explanation regarding the seismic damage evaluation of reinforced concrete bridge piers.

The combined effects of telmisartan and ramipril on hypertension and cardiovascular injury

이도형,Kim Min-Tae,Lee Hyung-Won,한주희,명창선 한국약제학회 2022 Journal of Pharmaceutical Investigation Vol.52 No.4

Purpose More than half of hypertensive patients receive combination therapy with two or more drugs. For combination therapy with antihypertensive drugs, it is recommended to use complementary drugs with different mechanisms. In this study, the effects of combination therapy with telmisartan (an angiotensin II receptor type 1 blocker) and ramipril (an angiotensinconverting enzyme inhibitor) on blood pressure control and cardiovascular protection were verified. Methods The systolic blood pressure (SBP), mean arterial pressure (MAP), and heart rate of spontaneously hypertensive rats (SHRs) were measured using a telemetry system. The protective effect of the drug combination against cardiovascular injury was determined by examining ligation-induced myocardial ischemia/reperfusion in SHRs and cuff-induced neointimal formation in C57BL/6 mice. Results The combination therapy with telmisartan and ramipril significantly decreased SBP and MAP. In addition, the combination therapy significantly increased the expression of endothelial nitric oxide synthase and inhibited the proliferation of vascular smooth muscle cells by inhibiting DNA synthesis at the cuff-induced vascular injury site. Conclusion The results of this study suggest that combination therapy with telmisartan and ramipril is an effective strategy for the treatment of hypertension and complications of hypertensive disorders.

슬러지 농도계의 연구개발 동향

이도형,양승철,전재연,Lee Do-Hyeong,Yang Seung-Cheol,Jeon Jae-Yeon 한국유체기계학회 2006 한국유체기계학회 논문집 Vol.9 No.3