표준관입시험의 N값을 이용한 비배수전단강도 및 선행압밀응력의 추정

이성철,김지용,조성민,김태형,Lee, Sung-Cheol,Kim, Ji-Yong,Jo, Sung-Min,Kim, Tae-Hyung (사)한국토질및기초기술사회 2006 기술발표회 Vol.2006 No.-

This study researched N-Value, strength of clayey soil and preconsolidation pressure m order to variety application of standard Penetration test. We compared it makes on analysis of the relationship of the N-value and $q_u$ with relation formula is presented in existing, presented the estimated preconsolidation pressure by using the predicted undrained shear strength.

뇌실복강간 단락술(Ventriculoperitoneal Shunt)을 시행한 환자에서의 서혜부 탈장의 빈도와 특성

이성철,이혁준,김기홍,정성은,박귀원,김우기,Lee, Seong-Cheol,Lee, Hyuk-Joon,Kim, Ki-Hong,Chung, Sung-Eun,Park, Kwi-Won,Kim, Woo-Ki 대한소아외과학회 2000 소아외과 Vol.6 No.2

Ventriculoperitoneal shunt(VP shunt) for hydrocephalus is thought to inhibit the closure of processus vaginalis and promote inguinal hernia by increasing intraabdominal pressure. To estimate the patency rate of processus vaginalis and the incidence and characteristics of the inguinal hernia, 262 cases of VP shunt in early childhood between January 1980 and May 1998 at Seoul National University Children Hospital were reviewed retrospectively. Inguinal hernia developed in 28 cases(10.7 %), but six patients had an inguinal hernia before the VP shunt was placed. Patients who had a VP shunt before 6 months of age developed inguinal hernia in 16.2 %(12/74) of cases, patients shunted between 6 months and 2 years had an incidence of 12.4 %(11/89) and only 5.1 %(5/99) of patients operated upon after 2 years of age developed hernias. Twenty-two patients out of 256 cases (8.6 %) developed inguinal hernia after VP shunt, with male predominance(M : F=4.5:1). Eight patients developed inguinal hernia bilaterally(36.4 %). It is suggested that at least 14% of processus vaginalis is patent until 2 years old.

소아에서 수술을 요한 멕켈게실의 임상상

이성철,목우균,서정민,정성은,박귀원,김우기,Lee, Seong-Cheol,Mok, Woo-Kyun,Seo, Jung-Min,Jung, Sung-Eun,Park, Kwi-Won,Kim, Woo-Ki 대한소아외과학회 1995 소아외과 Vol.1 No.1

The incidence of Meckel's diverticulum(MD) in general population has been assessed as 2 percent. The major complications of MD are bleeding, perforation, and intestinal obstruction. In spite that the complication rate of Meckel's diverticulum is relatively high(about 4.2% during a lifetime), the preoperative diagnostic rate of complicated MD is very low. Authors investigated the clinical characteristics of complicated MD to improve the diagnostic rate. 16 patients with complicated Meckel's diverticulum who were operated upon at the Department of Pediatric Surgery, Seoul National University Children's Hospital from June 1985 to December 1993 were reviewed. Among the 16 patients with complicated MD, 12 patients(75%) were under 2 year-old and male were predominant(88%). The most common complication was bleeding patients with bleeding MD (8 cases) were diagnosed preoperatively as MD. 8 patients with other complications(perforation : 4 cases, obstruction : 4 cases) could not be suspected as complicated MD except one patient who had previous history of melena. These patients were diagnosed after exploratory laparotomy under the various impression other than MD. Among 12 patients with ulcer related complications such as bleeding and perforation, heterotopic gastric mucosa was found in 11 patients. In conclusion, in any children with unexplained acute abdomen, especially under 2 years old, complicated MD must be included in differential diagnosis. In children with obscure lower gastrointestinal bleeding, $^{99m}Tc$-pertechnetate scintigraphy is a useful diagnostic tool to rule out bleeding MD.

선천성 식도 협착증

이성철,한원식,김기홍,정성은,박귀원,김우기,Lee, Seong-Cheol,Han, Won-Shik,Kim, Ki-Hong,Jung, Sung-Eun,Park, Kwi-Won,Kim, Woo-Ki 대한소아외과학회 2000 소아외과 Vol.6 No.1

Congenital esophageal stenosis (CES) is a narrowing of the esophageal lumen from birth. Three types of CES have been described; tracheobronchial remnants (TBR), membranous web (MW), and fibromuscular stenosis (FMS). We reviewed the clinical features and the surgical outcome of 14 patients, pathologically confirmed as CES. Nine patients had TBR, 3 FMS, and 2 MVV. The mean age at operation was 3.8 years. Five patients were boys and 9 girls. Four patients had other congenital anomalies. Segmental resection of the lesion and end to end anastomosis was utilized in all cases except one who underwent myotomy. The stenotic segment was located at the distal esophagus in all patients. There were 8 complications in 6 patients, but no mortality. The mean follow-up period was 68 months. There were no feeding problems but 3 patients had minor gastroesophageal reflux. Our result indicates that segmental resection and anastomosis is a satisfactory surgical procedure in the management of CES.

한국 Peutz-Jeghers 증후군의 특징

이성철,이현국,양석진,정성은,박귀원,김우기,Lee, Seong-Cheol,Lee, Hyeon-Kook,Yang, Suk-Jin,Jung, Sung-Eun,Park, Kwi-Won,Kim, Woo-Ki 대한소아외과학회 1997 소아외과 Vol.3 No.1

Eight pediatric patients with Peutz-Jeghers syndrome were treated from 1984 to 1994 at the Department of Surgery, Seoul National University Children's Hospital. We reviewed the clinical features of our own 8 cases as well as 56 cases reported in Korean literatures. The results were compared to those of western reports. Gastrointestinal complications in our series were more frequent than in the Korean series, but the distribution of polyps was similar. The Korean series showed the following characteristics compared to the western reports; demographic backgrounds were similar; gastrointestinal symptoms were more common; location of the polyp was more frequent in colon (2 times); and the most prevalent site of malignant change was the colon in Korean cases.

착지 높이에 따른 하지관절의 부상 메카니즘

이성철(Sung Cheol Lee),김경훈(Kyoung Hun Kim),조준행(Joon Haeng Cho),문곤성(Gon Sung Moon) 한국사회체육학회 2010 한국사회체육학회지 Vol.0 No.42

The purpose of this study was to examine common injury mechanism of lower extremity joint according to landing height. Sixteen university student with the right leg as dominant were instructed to perform landing tasks from 30cm, 45cm heights. Force plate and motion analysis system(VICON) were used to capture kinetic and kinematics data, respectively. For each variable, a paired t-test(p<.05) was used to determine whether there were significant differences in landing height. As a result of this study, The results showed increased eversion angle at IC in ankle joint and increased flexion among three point(IC, AVGRF, AMKF) in knee joint and at AMKF point in hip joint. And it showed increase varus at AMKF in knee joint and increased abduction at IC and AVGRF point in hip joint. In comparison to the 30cm, all of direction showed increased GRF except lateral direction and also take shorter time to reach peak GRF in posterior, lateral, vertical direction and loading rate was higher. The results also showed that ankle, knee, and hip were absorbed the power with increasing angle of each joint. This suggests that increasing angle of joint may reduce the impact on lower extremity during landing. It is considered that few significant differences were found among three point in kinematic data. but several significant differences were found in kinetic data. The results of this study suggest that landing height may be a one of variable to increase injury. In order to obtain meaningful results regarding the injury mechanism of lower extremity joint, more suitable and real situation tasks will be needed in the future study.

신경 전기 자극과 등척성 운동이 대퇴사두근력에 미치는 영향

이성철(Sung-Cheol Lee),채정룡(Jeong-Ryong Chae),김형준(Hyung-Jun Kim) 한국생활환경학회 2009 한국생활환경학회지 Vol.16 No.3

The purpose of this study was to compare the effectiveness of both neuromuscular electrical stimulation (NMES) and isometrical exercise (IE) to strengthen the quadriceps femoris muscle. The relationships between the strength changes and the relative force and duration of training contractions were also studied. The subjects were divided into three group. The control group (n=6) received no exercise and/or stimulation. The isometric exercise(IE) group (n=6) performed maximum isometric contractions, and the neuromuscular electrical stimulation(NMES)(n=6) engaged electrically stimulated isometric contractions, three days a week for four weeks. Data were analysed using a repeated measured analysis of variance (ANOVA) to determine differences among treatments. Where ANOVA revealed a significant difference. a Duncan post test was administered to locate difference. Significance was accepted when p<.05. All data are presented as the mean±SD. Results showed that both IE group and NMES group were found to have an increase in strength significantly greater (p<0.05) than the control group at 4 week. But between IE group and NMES group were not found to have an difference in strength significantly. The relative increase in isometric strength, using IE and NMES, may be determined by the ability of the subjects to tolerate longer and more forceful contractions. Suggestions for further research and implications for the clinical of IE and NMES for strength-training are discussed.

십이지장 벽내 혈종: 보존적 요법의 재조명

이성철 ( Seong Cheol Lee ),이호석 ( Ho Suk Lee ),정성은 ( Sung Eun Jung ) 대한외상학회 1990 大韓外傷學會誌 Vol.3 No.1

Intramural duodenal hematoma secondary to blunt abdomial trauma is a rare abdominal injury. Until early 1970s operation was preferred management. But after successful non-operative management of duodenal hematoma in 8 out of 9 children by Holgerson and Bis-hop in 1977 it is generally managed nonoperatively in children. But in 1988 Thoms and Ric-ketts reported 3 consecutive cases which they failed to manage nonoperatively and rec-ommeded surgical intervention when 10 days of medical management fails to achieve complete resolution. We experienced a natural course of duodenal obstruction by intramural hematoma and subsequent fibrosis which necessiated duodenojejunostomy 166 days after abdominal trauma in 7 year-old boy. We reviewed our case and agree with Thoms and Ricketts recommendation.

CNT 혼입 PVA-ECC 휨 거동

이성철(Lee, Seong-Cheol),심연희(Sim, Yeonhui),조수경(Cho, Su-Kyoung),이동민(Lee, Dongmin),유성원(Yoo, Sung-Won) 한국콘크리트학회 2021 한국콘크리트학회 학술대회 논문집 Vol.33 No.2

이 연구에서는 PVA-ECC에서 탄소나노튜브(CNT) 혼입에 따른 휨 거동을 실험을 통해 분석하였다. 이를 위해 0.1∼0.3%의 총 4가지 CNT 혼입률을 실험 변수로 고려하였으며, 변수 별로 보 실험체 제작 후 4점재하 실험을 수행하였다. 실험 결과 CNT 혼입률이 0.2%일 때 최대 휨강도 및 연성도가 가장 우수한 것으로 나타났다. CNT 혼입률이 0.3%인 경우 오히려 실험 결과에서의 편차가 증가하고 휨 연성도가 감소하는 것으로 나타났다. In this paper, flexural behavior of PVA-ECC with CNTs was investigated through bending test. 4 CNTs wtr. were considered as a test variable, and 4-points bending tests were conducted. Test results indicated that the specimens with 0.2% wtr. CNTs exhibited better performance on the maximum flexural strength and flexural ductility. When 0.3% wtr. CNTs were added, variation on the test results increased and flexural ductility decreased.

다기능·경량 하이퍼 콘크리트 성능에 따른 전달길이 및 균열폭에 대한 해석적 검토

이성철 ( Lee Seong-cheol ),이동민 ( Lee Dongmin ),유성원 ( Yoo Sung-won ) 한국구조물진단유지관리공학회 2021 한국구조물진단유지관리공학회 학술발표대회 논문집 Vol.25 No.1

최근 들어 세계 최고 수준의 첨단 나노기술을 접목하여 가벼우면서 강도가 높은, 열화 원인을 근본적으로 차단하는 다기능·경량 하이퍼 콘크리트(MLHC)에 대한 개발 연구가 활발히 진행되고 있다. 이 연구에서는 사용성 관련 MLHC에 요구되는 조건 중 사용성 검토에 필수적인 균열폭에 대해, MLHC의 탄성계수 및 부착강도의 변화에 따른 영향을 해석적으로 검토하였다. 검토결과, 일반 콘크리트 대비 탄성계수비 및 부착강도비가 감소할수록 전달길이 및 균열폭이 증가하는 것으로 나타나, MLHC의 탄성계수 및 부착강도에 대한 제한이 필요한 것으로 나타났다.