군말뚝에 작용하는 부주면 마찰의 영향

이철주(Lee Cheol Ju),이진형(Lee Jin Hyung) 대한토목학회 2005 대한토목학회논문집 C Vol.25 No.5

활로씨 4 증후군에서의 좌심실 용적에 관한 연구

이철주,심봉섭,Lee, Cheol-Ju,Sim, Bong-Seop 대한흉부심장혈관외과학회 1985 Journal of Chest Surgery (J Chest Surg) Vol.18 No.1

There are several factors influencing post-operative mortality in Tetralogy of Fallot, such as degree of RV outflow tract obstruction, combined anomaly, and age of the patient. Another factor is preoperative left ventricular volume reported by Kirklin and Graham in 1978. From March to September, 1984, 10 patient with Tetralogy of Fallot have been taken biplane cinecardioangiography [LAO and RAO projection] for measuring left ventricular volume by area-length method. The mean age of the patients was 84.9 [S.D.] and 3 males and 7 females were there. Mean value of left ventricle was 62.9ml/m2, which was no statistically difference from normal value. [p value=0.08]. In conclusion, though this study suggests that there is some decrease of left ventricular end-diastolic volume in Tetralogy of Fallot preoperatively as compared with normal individuals, further evaluation is needed to make it confirmatory with more number of patients and lesser range of age of the patients submitted to the study.

토목기술자는 플랫랜더(Flatlander)인가?

이철주(Cheol Ju Lee) 대한토목학회 2022 대한토목학회지 Vol.70 No.9

중국 통지대(同濟大)의 토목공학 교육 및 연구

이철주(Cheol-Ju Lee) 대한토목학회 2007 대한토목학회지 Vol.55 No.10

국가연구개발에 관한 연구현황 분석

이철주(Cheol-Ju Lee) 한국기술혁신학회 2018 기술혁신학회지 Vol.21 No.1

최근 국가연구개발사업에 대한 재정지원 증가율이 하락하고 있는 상황에서 국가연구개발사업의 효율적인 재원배분, 운영 및 관리가 더욱 중요시되고 있다. 이러한 시점에서 본 연구는 국가연구개발사업 자체에 대한 체계적이고 과학적인 연구의 필요성을 인식하고 국가연구개발사업에 관한 국내 연구현황에 대하여 분석을 실시하였다. 본 연구에서는 첫째로 기존 선행연구들과 법령을 바탕으로 국가연구개발사업에 대해 기획, 선정, 관리, 성과 등 각 수행 단계를 중심으로 하는 분류기준을 마련하였고, 둘째로 그 분류기준을 사용하여 최근 5년간 국내 학술지 문헌에 게재된 국가연구개발사업에 대한 연구들을 12개 분야로 구분하여 분야별 연구현황을 분석하였다. 마지막으로 연구 문헌들의 분야별 동시 분류 현황을 활용하여 네트워크 분석을 실시함으로써 각 분야의 연계현황과 영향력을 파악하였다. 연구결과 성과와 관련된 분야들이 연구 문헌 수가 많고 타 분야와 연계도 활발한 것을 확인할 수 있었고, 선정관련 분야들과 인프라 분야 등이 연구 수 또는 타 분야와 연계가 부족한 것을 확인할 수 있었다. 본 연구는 국가연구개발사업에 대한 분야별 연구현황과 연계현황에 대한 체계적 조망을 통하여 분야 간 연계와 후속연구가 더욱 필요한 분야를 도출하였다는 데 의의가 있다. With the recent slowdown of R&D budget growth rate, efficient resource allocation, operation and management of national R&D is becoming more important. At this point, recognizing the necessity of systematic and scientific research on the national R&D itself, this study analyzed previous researches on national R&D of Korea. In this study, based on the previous researches and laws, national R&D was classified according to the major stages such as planning, selection, management, performance and so on. Secondly, by using the classification criteria forged, previous researches on the national R&D published in domestic journals for the last 5 years were divided into 12 categories, and the status of researches in each field was analyzed. Lastly, through network analysis, linking status and influence of each fields were identified by using co-classification information of research literatures. As a result of this research, the performance related fields were the most active ones in terms of the number of research literatures, and connections with other fields, while the fields such as selection and infrastructure were lacking in the number of research and linkage. This study can find its meaning in identifying research fields that need more studies and connections with other areas by systematic analysis of previous studies on Korean National R&D.

수직응력의 감소가 부마찰이 작용하는 말뚝의 거동에 미치는 영향

이철주(Lee Cheol-Ju) 대한토목학회 2009 대한토목학회논문집 C Vol.29 No.1

부마찰이 작용하는 말뚝 주변지반의 수직 응력은 전단응력 전이 과정을 통해 감소하게 된다. 본 연구에서는 3차원 유한차분 해석을 실시하여 부마찰이 작용하는 단독말뚝 인근 지반의 수직응력 및 수평응력의 감소 및 그로 인한 말뚝의 거동변화에 대한 분석을 실시하였다. 또한 말뚝인근 지반의 수직응력 감소를 고려할 수 있는 간단한 식을 제안하였다. 말뚝에 부마찰이 작용하는 경우 Greenfield 조건에 비해 지반의 수직 및 수평응력이 상당히 크게 감소하는 것으로 나타났다. 수직응력이 감소되는 수평범위는 그리 넓지 않아서 최대 4-8 D 정도 인 것으로 분석되었다. 여기서 D는 말뚝의 직경이다. 본 연구를 통해 분석된 바에 의하면 부마찰력의 평가에 일반적으로 널리 이용되는 β-방법에 의해서는 부마찰력이 과다하게 평가될 수 있는 것으로 나타났으며, 따라서 원래의 공식에 수직응력의 감소를 반영할 필요가 있는 것으로 판단된다. Vertical soil stress near a pile subjected to negative skin friction (NSF) may be reduced due to shear transfer at the pile-soil interface. A three-dimensional finite difference analysis has been performed to clarify the influence of vertical and horizontal stress reductions on the pile behavour. In addition, a simple equation has been proposed to estimate vertical stress reduction of the soil near the pile. The vertical and horizontal stresses are reduced by substantial amount compared to corresponding stress components at the Greenfield condition. The horizontal extent of vertical stress reduction of the soil near the pile is rather limited to about up to 4-8 D, where D is the pile diameter. The findings from the current research indicate that widely used β-method may result in over-estimation of dragload (compressive force on piles due to NSF) and hence stress reduction needs to be incorporated in the original equation.

현행 토목기사 자격증 시험에 대한 비판적인 견해

이철주(Cheol Ju Lee) 대한토목학회 2021 대한토목학회지 Vol.69 No.4

혈소판 응집능에 미치는 인슐린의 in vitro 효과에 관한 연구

박철주(Cheol Ju Park),조재현(Jae Hyun Cho),강호철(Ho Cheol Kang),선영덕(Young Duck Sun),양승원(Seung Won Yang),정민영(Min Young Chung),이태희(Tai Hee Lee) 대한내과학회 1996 대한내과학회지 Vol.51 No.1

N/A Objectives: It has been suggested that functional abnormalities of platelets play a role in the pathogenesis of diabetic macro- and microangiopathy. Platelets obtained from diabetic patients have been shown to exhibit increased sensitivity to aggregating agents. It was reported that insulin influence on platelet and the long term insulin deficiency might account for the enhanced platelet aggregability frequently observed in diabetic patients. Our aim in this study was to clarify the influence of insulin on platelets in vitro. Methods: We investigated the effects of insulin on platelets response by incubating PRP(platelet rich plama) at 37℃ with different concentrations of the insulin for 5 or 30 min before adding the aggregating agents. Insulin final concentratons were 40, 100μIU/ml, assuming that the basal insulin concentration of PRP is 10 μIU/ml. The responses of platelets to ADP(adenosine diphosphate) and collagen were examined under basal conditions and after the addition of insulin, and they were quantified as the maximal aggregation(M) and T1/2(time consumed to reach 50% of the maximal aggregation). Results: 1) The subjects aged 27.4±2.5(mean±SE) years with body weight 62.5±6.3 kg. 2) The maximal aggregation of the control platelet in response to ADP(60.3±2.7%) was significantly reduced after PRP incubation for 30 min with 40 μIU/ml insulin(52.7±2.7%, 100 μIU/ml insulin(48.7±3.2%) (p<0.01). 3) The T1/2 of the control platelet in response to ADP(30.9±1.9sec) was significantly increased after PRP incubation for 30 min with 40pIU/ml insulin (36.6 ±1.7sec), 100 p μIU/ml insulin(38.3±1.7sec) (p<0.01). 4) The maximal aggregation of the control platelet in response to ADP(60.3±2.7%) was significantly reduced after PRP incubation for 5 min with 100 μ IU/ml insulin(56.9±2.5%), PRP incubation for 30 min with 100 μIU/ml insulin(48.7+3.2%)(p<0.01). 5) The T1/2 of the platelet incubated for 5 min in response to ADP(31.9±2.1sec, 32.5±2.0sec) was significantly increased after 30 min of incubation(36.6 ±1.7sec, 38.3±1.7sec) at 40μIU/ml, 100μIU/ml insulin concentration(p<0.01). 6) The maximal aggregation of the control platelet in response to collagen (63.9±2.8%) was significantly reduced after PRP incubation for 30 min with 40 p IU/ml insulin(58.3±3.0%), 100μIU/ml insulin(55.1±3.3%) (p<0.01). 7) The maximal aggregation of the control platelet in response to collagen(63.9±2.8%) was significantly reduced after PRP incubation for 5 min with 100 μIU/ml insulin(57.8±2.9%), PRP incubation for 30 min with 100 μIU/ml insulin(55.1±3.3%)(p<0.01). Conclusion: Insulin reduces the platelet response to ADP, collagen in vitro, especially in 30 min PRP incubation at same concentration.

대학인으로서의 삶의 수월성 추구

이철주,Lee, Cheol-Ju 한국대학교육협의회 1987 大學敎育 Vol.29 No.-

한국의 대학과 이과대학

이철주,Lee, Cheol-Ju 한국대학교육협의회 1984 大學敎育 Vol.9 No.-