네트워크 관리 - NMS만으로는 부족하다

이성철,Lee, Seong-Cheol 한국데이터베이스진흥원 1997 디지털콘텐츠 Vol.8 No.-

네트워크 관리자들은 흔히 네트워크 관리 시스템(NMS)에 모든 것들을 의지해 버리는 특성을 지니고 있다. 장애분석과 성능분석, 보안성 제공 등을 간단히 해결해주기 때문이다. 하지만 이것은 위험천만한 일이다. 그것은 현재 대부분의 NMS가 트래픽 분석 방법론을 제시해 주지 않을 뿐더러 분석이나 해결책 보다는 자료제공의 성격을 많이 띠고 있기 때문이다. 따라서 현재의 NMS로는 네트워크를 총체적으로 관리하기에 부족한 점이 없지 않다. 기존 NMS의 단점을 보완하고 있는 트래픽 분석 시스템을 들여다 보자.

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.

담도 폐쇄증에서 광범위 간문부 절제 및 간문부-공장 문합술의 치료성적

이성철,Lee, Seong-Cheol 대한소아외과학회 1997 소아외과 Vol.3 No.2

Extended porta hepatis dissection and hepatic portojejunostomy was performed on 14 biliary atresia patients during last 13 years by a single surgeon. The average age at operation was 68 days(range from 37 days to 98 days). The patients were admitted for 8 weeks postoperatively for administration of parenteral antibiotics. There was one operative mortality due to acute hepatic necrosis. Among 13 patients remaining, 12(92.5 %) became chemically jaundice-free within 36 weeks postoperatively(average 16.8 weeks). the earliest 8 weeks, and in one patients jaundice persisted. Five(38.5 %) patients developed cholangitis after operation. Among jaundice-free patients, one patient died of unrelated disease 2 years after hepatic portojejunostomy, who underwent left lateral segmentectomy because of a biloma. Eleven survivors(78.6 %) are jaundice-free. The oldest one is 13 years old, enjoying a normal life. The mean period of follow-up is 7 years and 3 months.

냉간 압축 하에서 금속 분말의 치밀화 거동

이성철,김기태,Lee, Seong-Cheol,Kim, Gi-Tae 대한기계학회 2002 大韓機械學會論文集A Vol.26 No.1

Densification behavior of aluminum alloy(A16061) powder was investigated under cold compaction. Experimental data were obtained under triaxial compression with various loading conditions. A special form of the Cap model was proposed from experimental data of A16061 powder under triaxial compression. The proposed yield function and several yield functions in the literature were implemented into a finite element program (ABAQUS) to compare with experimental data for densifcation behavior of A16061 powder under cold isostatic pressing and die compaction. The agreement between finite element calculations from the proposed yield function and experimental data is very good under cold isostatic pressing and die compaction.

소아의 이소성 경부흉선 1예

이성철,양석진,김우기,Lee, Seong-Cheol,Yang, Seok-Jin,Kim, Woo-Ki 대한소아외과학회 1996 소아외과 Vol.2 No.1

Aberrant migration of thymic tissue occurs as an ectopic thymus in the mediastinum, base of skull, tracheal bifurcation, and cervical region. A recent review of the literature by Nowak et al. showed over 70 reported cases of aberrant thymus or thymic cyst in patients who presented with primary neck masses. Authors experienced a case of ectopic cervical thymus and reviewed the literature. A one-year-old boy with left neck swelling which had been noticed since one month of age visited out patient clinic. Ultrasonography showed a well-defined cystic mass containing homogeneous, low-echogenic content locating in the lateral aspect of the left carotid sheath. Operation was performed under the impression of branchial cleft cyst. At surgery, a multiseptated, well-encapsulated, brownish and doughy mass which was extending into the vicinity of the carotid bifurcation with sland stalk-like portion ending between the hypoglossal nerve and external carotid artery was excised completely. The cut-surface showed homogenous solid mass, and on frozen section the tissue revealed a normal thymic histology. Postoperative ultrasonography showed bilateral thymus in the superior mediastinum. The patient has no immunologic problem and is doing well now. 1세된 남아에서 세열낭종을 의심한 좌측 경부 종양이 수술을 시행한 결과 고형종양이였고, 조직검사상 이소성 흉선으로 판명되었다. 술후 초음파상 흉선은 정상적으로 있었고, 현재 환자의 면역기능은 아무 이상없이 정상으로 자라고 있다.

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.

저절로 파열된 횡경막 이완증 1예

이성철,김기홍,Lee, Seong-Cheol,Kim, Ki-Hong 대한소아외과학회 2000 소아외과 Vol.6 No.1

Spontaneous rupture of the eventrated diaphragm is not common. The authors report a case of spontaneous rupture of the congenital diaphragmatic eventration. An 8 year-old girl with right congenital diaphragmatic eventration and nephrotic syndrome was seen in emergency room because of severe abdominal pain and vomiting. She had intermittent abdominal pain for 1 year. Plain chest X-ray and ultrasonography showed entrapped bowels in the right thoracic area. Exploratory laparotomy revealed a ruptured right eventration. THE displaced abdominal viscera were repositioned into the abdominal cavity and the ruptured diaphragm was trimmed and plicated. The postoperative course was uneventful. Only one case of spontaneous rupture of eventrated diaphragmatic has been reported in the English literature.

영아 Bochdalek 탈장의 임상적 고찰

이성철,성숙환,Lee, Seong-Cheol,Seong, Suk-Hwan 대한흉부심장혈관외과학회 1987 Journal of Chest Surgery (J Chest Surg) Vol.20 No.4

Authors carried out a retrospective study in 22 infants with Bochdaleck`s hernia who were operated upon, the results are; 1] the male to female ratio was 2:1 and the incidence of left side was threefold prevalent than right, 2] the chief complaint of those who were operated upon in neonatal period was dyspnea and diagnosis was possible by chest A-P, 3] primary repair was possible except one patient in whom a prosthesis was used. 4] complication occurred in 41% and pulmonary complication was most common including 5 pneumothorax, 5] mortality rate was 14%, the deaths occurred in infants who were operated upon within 48 hours of life and the lesion was left without sac, the defect was larger than average and all died within 72 hours after operation.

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.

FBG 센서를 이용한 강연선 전달길이 측정

이성철,최송이,신경준,김재민,이환우,Lee, Seong-Cheol,Choi, Song-Yi,Shin, Kyung-Joon,Kim, Jae-Min,Lee, Hwan-Woo 한국전산구조공학회 2015 한국전산구조공학회논문집 Vol.28 No.6

In this paper, an experimental program has been conducted to investigate transfer length in high strength concrete members pretensioned through a seven-wire strand with FBG sensors. To measure transfer length, five members were fabricated, which had a length of 3 m and a cross-section of $150{\times}150mm$. It was measured that the concrete compressive strength was 58MPa at pretensioning. Test results indicated that more precise and reliable measurement on the transfer length was attained with FBG sensors than conventional gauges attached on concrete surface. Through comparing the measured transfer length and predictions, applicability of several transfer length models in literature was investigated. This paper can be useful for relevant research field such as investigation on the bond mechanism of a seven-wire strand in concrete members. 본 논문에서는 프리텐션된 고강도 콘크리트 부재에서의 전달길이를 측정하기 위해 FBG 센서가 기입된 스마트 강연선을 활용하여 실험을 수행하였다. 전달길이 측정을 위해 길이 3m, 단면 $150{\times}150mm$의 고강도 콘크리트 시험체를 총 5개 제작하였으며, 프리텐션 도입 시 콘크리트 압축강도는 58MPa로 측정되었다. 실험 결과 콘크리트 표면에 부착하는 기존의 전기 저항식 게이지보다 FBG 센서로부터 보다 정밀하고 신뢰성있는 강연선의 전달길이를 계측할 수 있는 것으로 나타났다. 계측결과로부터 산정된 강연선 전달길이를 기존의 여러 모델들과 비교하였으며, 이를 통해 고강도 콘크리트 부재에서의 전달길이 산정에 대한 기존 모델들의 적용성을 분석하였다. 본 연구 내용은 향후 강연선의 부착 특성 분석 등의 관련 분야 연구 등에 유용할 것으로 기대된다.