도심지 굴착에 따른 토류구조물 및 인접지반의 유한요소 해석기법

이봉렬,김광진,김학문,Lee, Bong-Ryeol,Kim, Gwang-Jin,Kim, Hak-Mun 한국지반공학회 1997 지반 : 한국지반공학회지 Vol.13 No.5

도심지 지반굴착 해석을 위한 전용 유한요소 프로그램(EM)을 개발하였다. 기존 범용 프로그램과는 달리 사용자가 간단한 입력자료를 작성하고 전.후처리는 자동으로 도화 출력되므로 굴 착해석에 쉽게 사용될 수 있도록 하였다. 특히, 새로 개발된 GDHM재료모델 ((GDHM, General ized Decoupled Hyperbolic Model)은 8면체평면상에서의 응력경로에 따른 강도변화를 고려하였다. 개발된 EM프로그램은 대형 굴착토조모형실험 결과와 비교 검토함으로서 개발된 재료모델과 굴착전용프로그램의 신뢰성을 검증하여 비교적 정확도가 높은 결과를 얻었고, 향후 미비점을 보완, 개선하여야 한다. A finite element computer program is developed for the specific analysis of earth retaining structures in urban excavation. Unlike the existing multi -purpose FEM programs, the newly developed program (EM) consists of very simple and easy data processing system for the urban excavation. A non-linear material model(GDHM, Generalized Decoupled Hyperbolic Models is deviloped and implemented in the program EM. The results of large scale model tests for earth retaining structures are used for the vertification of EM along whit GDHM, and the results were satisfactory, but it was found that the program EM needs minor modification for the improvement of its accuracy.

3차원 터널해석에 의한 강관보강형 다단그라우팅의 보강효과

이봉렬,김형탁,김학문,Lee, Bong-Ryeol,Kim, Hyeong-Tak,Kim, Hak-Mun 한국지반공학회 1996 지반 : 한국지반공학회지 Vol.12 No.4

본 논문은 비선형 유한요소 프로그램을 이용하여 강관보강형 다단그라우팅의 지반보강효과와 주변지반의 거동을 검토하기 위하여 지반조건이 터널천단부에 충적층이 분포하여 강관다단그라우팅을 적용한 현장을 대상으로 유한요소 2차원과 3차원 모델로 나누어 해석하였다. 해석 결과 강관보강효과를 분석하기 위해서는 2차원해석보다는 3차원해석이 필수적 임을 알 수 있었으며, 그 효과는 막장부근의 음력집중현상을 골고루 분포시켜주는 강관의 강성에 의하여 안전율이 상대적으로 높아짐을 확인할 수 있었다. 한편 터널천단의 침하량 변화는 터널막장위치가 측정지점에 도달하기 이전에 총예상변위의 40%정도가 발생되며, 막장위치가 측정지점을 통과하여 터널직경정도의 거리에 도달하는 동안 전체예상변위의 60%가 발생될 수 있는 것으로 나타났다. 또한 강관보강으로 인하여 주변지반의 변위 및 응력의 억제범위는 터널 천단부 즉 깊이비 0.83 에서 0.38범위와 터널막장전방 26(d:터널직경)지점까지 나타나며, 변위억제효과는 총 예상변위량의 약 200정도임을 알 수 있었다. In this study it was analyzed by 2-D FEM and 3-D FEM to evaluate the ground reinforceing effect of steel pipe reinforced multi -step grouting (SPRG) technique and the behavior of ground in the vicinity using the nonlinear FEM program for the ground condition of alluvium located on the top of tunnel applied by SPRG technique. It was found that the nonlinear 3-D analysis performed better than 2-D analysis in evaluating the usefulness of the SPRG technique, and it was also found that the safety was relatively secured by the stiffness of steel pipe to distribute the concentrated stress in the tunnel faceing. It was reported that the change of settlement on the top of tunnel becomes about 40% of the total expected settlement before tunnel faceing reaches tunnel gauging point, and 60% of the total expected settlement while tunnel facing passes tunnel gauging point and takes a distance about tunnel diameter. With the aid of the SPRG technique the control range of displacement and stress of the ground in the vicinity could be reached up to tunnel top, namely depth ratio from 0.38 to 0.83 or 2D(D : tunnel diameter) before the tunnel facing, and about 20% of settlement control in this particular case was possible.

삼중압 열회수 증기발생기와 중기터빈 시스템의 열설계 해석

김동섭,이봉렬,노승탁,신흥태,전용준,Kim, Dong-Seop,Lee, Bong-Ryeol,No, Seung-Tak,Sin, Heung-Tae,Jeon, Yong-Jun 대한기계학회 2002 大韓機械學會論文集B Vol.26 No.3

A computation routine, capable of performing thermal design analysis of the triple-pressure bottoming system (heat recovery steam generator and steam turbine) of combined cycle power plants, is developed. It is based on thermal analysis of the heat recovery steam generator and estimation of its size and steam turbine power. It can be applied to various parametric analyses including optimized design calculation. This paper presents analysis results for the effects on the design performance of heat exchanger arrangements at intermediate and high temperature parts as well as steam pressures. Also examined is the effect of steam sources for deaeration on design performance.

약물방출 스텐트 시술을 받은 급성 심근경색증 환자에서 항인지질 항체의 존재가 주요 심혈관 사건에 미치는 영향

정연수 ( Yeoun Su Jung ),이봉렬 ( Bong Ryeol Lee ),류한준 ( Han Jun Ryu ),박민규 ( Min Kyu Park ),김민희 ( Min Hee Kim ),정호진 ( Ho Jin Jung ),이준영 ( Jun Young Lee ),강현재 ( Hyun Jae Kang ),정병천 ( Byung Chun Jung ),장순희 ( 대한내과학회 2013 대한내과학회지 Vol.84 No.5

Background/Aims: Several studies have reported an association between antiphospholipid antibodies (APA) and major adverse cardiovascular events (MACE) following acute myocardial infarction (AMI). However, the relationship between APA and the prognosis after drug-eluting stent (DES) implantation in patients with AMI is not known. Methods: Thus, we investigated the relationship between the incidence of MACE and APA levels in patients with AMI who underwent successful DES implantation. Results: Of 182 patients, 78 (42.9%) tested positive for APA. Lupus anticoagulant was positive in 37.6% (68 of 181) patients, anticardiolipin antibody IgM was positive in 8.3% (15 of 180), and anticardiolipin antibody IgG was positive in 1.7% (3 of 180) patients. At follow up, a MACE had occurred in 11 (14.1%) patients in the APA-positive group and in seven (6.7%) patients in the APA-negative group (p = 0.099). Conclusions: No significant association was found between the incidence of MACE and the presence of APA in patients with AMI who underwent successful DES implantation. (Korean J Med 2013;84:681-689)

ST절 상승 급성 심근경색증 환자에서 혈전흡인술에 따른 신호평균화 심전도 비교

이준영 ( Jun Young Lee ),최원석 ( Won Suk Choi ),정병천 ( Byung Chun Jung ),이봉렬 ( Bong Ryeol Lee ),강현재 ( Hyun Jae Kang ),김재희 ( Jae Hee Kim ),강균은 ( Gyoun Eun Kang ) 대한내과학회 2016 대한내과학회지 Vol.90 No.1

Background/Aims: Percutaneous coronary intervention (PCI) is the standard method of treating ST-segment elevation myocardial infarction (STEMI). There is continuing uncertainty as to whether reducing the thrombus burden through catheter aspiration improves the arrhythmogenic structure of the myocardium in STEMI. We compared the changes in electrical instability after thrombus aspiration-assisted primary PCI using conventional primary PCI. Methods: The study population included 170 consecutive patients with STEMI who underwent primary PCI. The patients were divided into 80 patients who underwent primary PCI only and 90 patients who underwent thrombus aspiration before PCI. The signal- averaged ECG (SAECG) was obtained 5 ± 2 days after the intervention. Results: There were no significant differences between the groups in terms of sex, age, cardiovascular risk factors, or time from the onset of symptoms to treatment. The duration of the low amplitude signals less than 40 μV (LAS40), duration of the QRS complex (QRSD), and root mean square voltage of the terminal 40 ms of the QRS complex (RMS40) did not differ between the thrombus aspiration and no thrombus aspiration groups. The incidences of QRSD > 114 ms and RMS40 < 20 μV were significantly lower in the thrombus aspiration group than the no thrombus aspiration group (19 vs. 8, p = 0.011 and 16 vs. 8, p = 0.047, respectively), while the incidence of LAS > 38 ms was significantly higher in the non-thrombus aspiration group (18 vs. 8, p = 0.018). Conclusions: Among random patients with STEMI, thrombus aspiration improved all of the parameters of SAECG, which is related to ventricular arrhythmogenesis, although the long-term clinical outcomes need to be assessed. (Korean J Med 2016;90:26-31)

건강성인에서 성별 및 연령별 혈청지질의 정상치 - 특히 이상지혈증의 빈도를 중심으로 -

권삼(Sam Gweon),구성모(Seong Mo Koo),조봉기(Bong Kee Cho),정기제(Gih Jeh Jeong),이중기(Choong Ki Lee),정의룡(Eui Ryong Cheong),류재근(Jae Kean Ryu),이봉렬(Bong Ryeol Lee),채성철(Shung Chull Chae),전재은(Jae Eun Jun),박의현(Wee Hyun 대한내과학회 1996 대한내과학회지 Vol.50 No.2

mg/dl) in men and women was 36.8 and 44.0%, respectively and that of high LDL-cholesterol(≥160 mg/dl) was 26.6% in men and 35.2% in women. Their frequencies were increased with age in both sexes. 4) There were no significant, differences in the mean values of total cholesterol, triglyceride, LDL-cholesterol, HDL-cholesterol and atherogenic index by residency. The frequency of high total cholesterol(≥200mg/dl) in Taegu and its rural area was 40.7% and 35.5%, respectively. Conclusion: These findings suggest that the mean concentrations of total cholesterol, triglyceride and LDL-cholesterol in men and women vary with age. The frequency of hypercholesterolemia (≥200 mg/dl) in men and women was about 40%, and increased with age. Values of HDL-cholesterol were not affected by age and sex

양측성 신동맥 협착증에서 발생한 급성 비대상성 심부전과 급성 신손상

정호진 ( Ho Jin Jung ),최원석 ( Won Suk Choi ),강현재 ( Hyun Jae Kang ),정병천 ( Byung Chun Jung ),이봉렬 ( Bong Ryeol Lee ),이종주 ( Jong Joo Lee ),이준영 ( Jun Young Lee ) 영남대학교 의과대학 2015 Yeungnam University Journal of Medicine Vol.32 No.2

Atherosclerotic renal artery stenosis (RAS) may result in hypertension, azotemia, and acute pulmonary edema. We report on a renal angioplasty with stent placement for bilateral RAS in a patient with acute decompensated heart failure and acute kidney injury. A 67-year-old female patient was admitted to our hospital with acute shortness of breath and generalized edema. Echocardiography showed left ventricular wall motion abnormality and the follow up electrocardiography showed T wave inversion in the precordial leads. We performed a coronary angiography to differentiate ischemic heart disease from non-cardiac origin for the cause of the heart failure. The coronary angiography showed no significant luminal narrowing, but bilateral RAS was confirmed on the renal artery angiography, therefore, we performed renal artery revascularization. After the procedure, the pulmonary edema was improved and the serum creatinine was decreased. Two weeks later, an echocardiography showed improvement of the left ventricular systolic function.

원발성 유미 심막증

손혁수 ( Hyuk Su Son ),김건현 ( Gun Hyun Kim ),김민선 ( Min Seon Kim ),여주천 ( Ju Chun Yeo ),이봉렬 ( Bong Ryeol Lee ),정병천 ( Byung Chun Jung ),이종주 ( Jong Joo Lee ) 대한내과학회 2005 대한내과학회지 Vol.69 No.-

Chylopericardium is a particularly rare clinical entity, generally related to thoracic and cardiac surgery, chest trauma, mediastinal tumor, mediastinal radiation, thrombosis of the subclavian vein, congenital lymphangiomatosis and large granular lymphocytosis. Unlike chylopericardium, primary chylopericardium is more rare disorder and should be diagnosed after exclusion of the known causes. We present a case of a 51-year-old male who was discovered to have a primary chylopericardium confirmed by an echocardiography & fluid analysis by pericardiocentesis. Primary chylopericardium was managed successfully with pericardiocentesis and drainage. We present the case with a review of literature. (Korean J Med 69:S824-S829, 2005)

중등도 이상의 심낭삼출 환자에서 임상상 및 장기예후

김대영 ( Dae Young Kim ),박진홍 ( Jin Hong Park ),신재대 ( Jae Dae Shin ),김봉수 ( Bong Soo Kim ),이현직 ( Hyun Jik Lee ),김재훈 ( Jae Hoon Kim ),장희상 ( Hee Sang Jang ),강현재 ( Hyun Jae Kang ),이봉렬 ( Bong Ryeol Lee ),정병천 ( 대한내과학회 2008 대한내과학회지 Vol.74 No.2

Background/Aims: Pericardial effusion (PE), which is more than a moderate amount, is usually accompanied with various underlying illnesses. However, there have been few reports on the long-term follow-up results of these cases, and even in the studies where the etiologies were well presented. Methods: 64 consecutive patients (mean age: 66.3 years, 23 males) with more than a moderate amount of PE, as confirmed by echocardiography, were analyzed for pericardial fluid and this was diagnosed according to ESC Executive Summary. The mean follow-up duration was 1.95±1.78 years and the final survival was assessed in November, 2006. Results: The etiologies were composed of malignancy-related PE (MRPE: 29.7%), tuberculosis pericarditis (40.6%), idiopathic pericarditis (18.8%), hypothyroidism (7.8%), and miscellaneous (3.1%). Mortality occurred in 21 cases (32.8%), of which 15 cases were attributed to MRPE. In all patients, the mean survival duration was 372±247.9 days after diagnosis, and the mean survival duration was 253±221.5 days after pericardiocentesis. Cardiac tamponade, constrictive pericarditis and recurrent pericarditis were presented in 15 cases (23.4%), 9 cases (14.1%) and 2 cases (3.1%) respectively. The chemistry findings of PE were of no use to differentiate the etiologies. Conclusion: Pericardial effusion of more than a moderate amount often manifested urgent symptoms such as cardiac tamponade and intractable dyspnea, and these conditions require therapeutic pericardiocentesis more frequently than diagnostic tests. The prognosis is usually subordinate to the progression of the underlying illness, and especially in case of MRPE. The occurrence of constrictive pericarditis should be monitored carefully. (Korean J Med 74:154-161, 2008)

ACE 길항제의 장기복용에 따른 기침의 발생빈도

박헌식,김진년,정의룡,류재근,이봉렬,조용근,채성철,전재은,박의현 慶北大學校 醫科大學 1995 慶北醫大誌 Vol.36 No.4

목적 : 근래에 와서 ACE 길항제가 고혈압 및 심부전 환자들에게 널리 사용되면서 임상에서 기침 때문에 사용이 제한되는 경우를 흔히 접하게 된다. 따라서 ACE 길항제의 주요 부작용인 기침에 관한 연구를 시행하였다. 대상 및 방법 : 대상은 1990년 1월부터 1994년 6월까지 경북대학교병원 순환기내과에서captopril과 enalapril을 복용하고 있는 남자 45례, 여자 63례로 모두 108례였고 이들의 평균연령은 57±11.2세였으며 63례에서 captopril을 복용하였고 45례에서 enalapril을 복용하였다. 이들에서 기침의 발생과 환자의 임상적 경과는 병력지에서 관찰하였고 대상환자중에 호흡기질환이 있는 경우는 제외하였다. 결과 : 1) ACE 길항제를 사용한 108례의 환자중 27례에서 기침이 발생하였으며(25%) 그 중captopril을 사용한 환자에서는 28.5%이고 enalapril을 사용한 환자에서는 20%였으나 양군간에 통계학적으로 유의한 차이는 없었다. 2) 투약후 기침이 발생한 때까지의 기간은 평균 225±256.7일이었고 투약후 대개 6개월이내에 기침이 발생하였으며 1년이 지나서도 5명에게서 기침이 발생하였다. 3) 기침의 발생빈도는 심부전환자군이 34.4%, 고혈압환자군에서 20.5%였다. 4) 기침의 발생빈도는 여자에서 28.5%, 남자에서 20%이였으나 통계학적으로 유의한 차이는 없었다. 5) 연령에 따른 기침발생율은 차이가 없었다. 6) 흡연여부에 따른 기침발생율은 차이가 없었다. 결론 : 기침은 ACE 길항제의 흔한 부작용이며 고혈압이나 심부전 환자에서 ACE 길항제를 사용할 때에는 기침의 발생에 적절한 주의가 필요하다. Background : Angiotensin converting enzyme inhibitors(ACEI) are increasingly being used to treat hypertension and congestive heart failure. In general, these durgs are well tolerated, but an unexpected and troublesome cough has been reported in patients taking captopril or enalapril. We studied the incidence and characteristics of ACEI induced cough. Method I Medical records of patients who were treated for hypertension and congestive heart failure in division of cardiology were reviewed retrospectively. Excluding patients with respiratory disease, 108 patients on either captopril(n = 63) or enalapril(n = 45) were selected(45 males and 63 females). Their mean age was 57±11.2 years. Seventy three cases used ACEI for hypertension and thirty five for congestive heart failure. Results : Twenty-five percent of 108 patients(n = 27) developed a cough(cough group) after the ACEI medication(28.5% for captopril vs 20% for enalapril : not significant). Mean duration of therapy until the cough developed was 225 days. The incidence of the cough was 34.4% in patients with congestive heart failure and 20.5% in patients with hypertension (not significant). There was no difference in age between the cough group and the non-cough group(56±9.5 years vs 57±12.4 years). The cough did not appear to be related to the dosage of medications and smoking habits. Conclusion : A cough is not an uncommon side effect in patients taking ACEI. Optimal clinical application of ACEI in the treatment of hypertension and congestive heart failure will require increased awareness of the cough.