http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
피동형 원자로의 Hydraulic Valve에 관한 연구
김융석,김상녕 경희대학교 산학협력기술연구원 1996 산학협력기술연구논문집 Vol.2 No.-
In a passive reactor, when the main coolant pump fails or the main coolant flow is not adequate, the reactor should be shutdowned and its decay power should be removed by passive methods. This passive function is controlled by the density locks which separates the main coolant from the high-borated cold pool water. In transients, however, the borated pool water can unnecessarily enter into reactor core through the unstable lower density lock. This drawback of density lock necessitates a hydraulic valve which, in normal operation condition, prevents the borated pool water from entering into the main coolant loop except a small amount of leaking flow. In a transient(main coolant pump head is not enough) its opening makes the pool water circulate the decay heat removal loop. The hydraulic valve which is in the stage of development is operated by the fluid mechanical force balance. So, the major parameters and the pressure drops of the valve could be analyzed with the mass and force balance equations for a control volume of the valve. The governing dimensionless numbers of the valve were also determined by theorical analysis. On the basis of above results, an one-third scale experimental rig including the hydraulic valve was designed. The experimental rig results have shown the successful performance and the characteristics of the valve.
초음파 진동절삭을 이용한 평면 광도파로와 유리의 미세 홈 가공특성에 관한 연구
이준석,김병국,정융호,이득우 한국공작기계학회 2002 한국공작기계학회 춘계학술대회논문집 Vol.2002 No.-
Recent years, optical components' are widely used in optical communication industry for high speed and mass storage data processing. Micro grooving of planar lightwave circuit and glass, those are widely used in optical component, are realized by polycrystalline diamond tool with ultrasonic vibration. To know the characteristics of brittle materials cutting, ultrasonic vibration cutting tool and machining system are built for the experiment. Grooving on planar lightwave circuit and glass experiments are performed and their shape are measured by photograph with microscope. It reveals that better groove shape with low chipping of planar lightwave circuit and glass are obtained by micro grooving machining with ultrasonic vibration. These experiments are considered as a possibility to the micro grooving of optical communication components.
구강에 발생한 편평상피암종의 MMP-2, MMP-9, TIMP-1, TIMP-2 발현과 EGFR 및 E-cadherin 발현의 상호연관성
조성재,권창석,김용환,윤혜경,김우형,이희철 인제대학교 백병원 2002 仁濟醫學 Vol.23 No.4
Objective : Matrix metalloproteinases(MMPs) are involved in the degradation of extracellular matrix, which is related to infiltrative growth and metastasis of tumor. Positive correlation between MMPs expression and clinico-pathologic parameters were reported, and MMPs expressions were regulated by tissue inhibitor of metalloproteinases(TIMPs) or cell adhesion molecules such as E-cadherin and epidermal growth factor receptor EGFR). The aim of this study is to evaluate the relationship between MMP-2, MMP-9 expressions and clinico-pathologic factors such as clinical stage. recurrence. histologic grade and invasion pattern, and between MMP-2 and MMP-9 Expressions and TIMP-1, TIMP-2, and E-cadherin expressions. Methods and Material : The materials were 55 cases of squamous cell carcinoma of the oral cavity, and immunohisdtochemical studies for MMP-2, MMP-9, TIMP-1, TIMP-2, E-cadherin and EGFR were performed. Clinico-pathologic factors such as clinical stage, recurrence, histologic grade and invasion pattern were recorded through microscopic examination and clinical record review. Statistical analyses between MMP-2, MMP-9 expressions and clinico-pathologic factors, TIMP-1, TIMP-2 expressions and EGFR and E-cadherin expressions were done. Results : 1. MMP-2 and MMP-9 expressions were noted in 30(54.5%) and 22(40.0%) of 55 cases, respectively. TIMP-1 and TIMP-2 expressions were observed in 21(38.2%) and 33(60.0%), and E-cadherin and EGFR expressions were found in 35(63.6%) and 26(47.3%) of 55 cases, respectively. 2. MMP-2 expression rate was slightly higher in cases without recurrence, and TIMP-2 expression rate was slightly higher in cases showing more infiltrative growth pattern. However, there were no significant differences of MMP-2, MMP-9, TIMP-1, and TIMP-2 expression rates according to other clinico-pathologic parameters were noted. 3. The expression rate of EGFR was higher in cases with well differentiation (p=0.0047), but no positive relationship between the expression rate of E-cadherin and histologic grade was found. There were no significant differences of the expression rates of E-cadherin and EGFR according to other clinico-pathologic parameters. 4. Cases with positive reaction for MMP-9 showed an increasing tendency of negative reaction for TIMP-1. However, signigicant relationships between MMP-2, MMP-9 expressions and TIMP-1, TIMP-2 expressions were not noted. 5. The expression rate of MMP-2 was higher in cases with positive reaction for Ecadherin and EGFR with no statistical significance. The expression rate of MMP-9 was significantly higher in cases with positive reaction for E-cadherin(p=0.0221), but there was no significant relationship between MMP-9 and EGFR expression. Conclusion : These results suggest that MMP-2, MMP-9, TIMP-1 and TIMP-2 expressions are involved in the development of oral squamos cell carcinomas, but MMP-2, MMP-9, TIMP-1, and TIMP-2 expressions might not seem to be a sueful prognostic factors because there were no significant relationship between clinicopathologic parameters, EGFR expression showed positive correlation with low histologic grace, so EGFR expression could be regarded as a good prognostic factor. In the progression of squamous cell carcinoma of oral cavity, MMP-9 and E-cadherin might be involved with positive correlation, but there were no significant correlations between MMP-2, MMP-9 and TIMP-1, TIMP-2 and EGFR expressions rate. Further study for other factors such as cytokines or growth factors except TIMP-1, TIMP-2 and EGFR will be needed.
Yoong-Seok Park,Young Soo Do,Hong Suk Park,Kwang Bo Park,Dong-Ik Kim 대한외과학회 2015 Annals of Surgical Treatment and Research(ASRT) Vol.88 No.4
Cone beam CT, usually used in dental area, could easily obtain 3-dimensional images using cone beam shaped ionized radiation. Cone beam CT is very useful for direct percutaneous sac injection (DPSI) which needs very precise measurement to avoid puncture of inferior vena cava or vessel around sac or stent graft. Here we describe two cases of DPSI using cone beam CT. In case 1, a 79-year-old male had widening of preexisted type II endoleak after endovascular aneurysm repair (EVAR). However, transarterial embolization failed due to tortuous collateral branches of lumbar arteries. In case 2, a 72-year-old female had symptomatic sac enlargement by type II endoleak after EVAR. However, there was no route to approach the lumbar arteries. Therefore, we performed DPSI assisted by cone beam CT in cases 1, 2. Six-month CT follow-up revealed no sign of sac enlargement by type II endoleak.
Yoong-Seok Park,Seon-Hee Heo,Dong-Ho Hyun,Young-Soo Do,Hong-Suk Park,Kwang-Bo Park,Young-Wook Kim,Yang-Jin Park,Chul-Hyung Lee,Dong-Ik Kim 대한외과학회 2017 Annals of Surgical Treatment and Research(ASRT) Vol.92 No.1
Purpose: Directional atherectomy (DA) was introduced for the management of infrainguinal arterial stenosis or occlusive lesions. The procedure success rate in the DEFINITIVE LE study was determined using radiologic imaging. The aim of our study was to determine the usefulness of intraoperative ultrasonography (USG) during DA for evaluating the early results of this procedure. Methods: Patients who underwent DA from January to December 2014 were reviewed retrospectively. Twenty lesions from 14 patients with femoral artery stenosis (>70% stenosis) with short segment occlusive lesions (<2 cm in length) were treated. Among 20 lesions, 3 were treated with the TurboHawk system with a protective device due to lesion calcification. The percentage of stenosis during and after DA was determined with USG. Results: Median follow-up was 5.1 months, and the procedural success rate (<30% stenosis at the end of the procedure) was 100% on angiography, but only 30% on intraoperative USG. On USG, median residual stenosis was 40% (range, 28%–42%) at the end of DA, 40% (range, 30%–55%) at 1 month, 55% (range, 35%–85%) at 6 months, and 64% (range, 60%–100%) at 1 year. There was one dissection, but no cases of perforation, pseudoaneurysm, or thrombosis. Primary patency, which was defined as a peak systolic velocity ratio ≤3.5 with no reintervention at 6 months, was found in 18 lesions (90%), and 11 of 14 patients (78.6%) were free of ischemic symptoms such as claudication at 6 months. Conclusion: Our results demonstrated that DA with intraoperative USG is an effective treatment option for short segment occlusive lesions of the femoral artery.
객체 정보의 검색량를 고려한 DHT 기반 P2P 시스템에서의 로드 밸런싱
서융석 ( Yoong-seok Seo ),송진우 ( Jin-woo Song ),양성봉 ( Sung-bong Yang ) 한국정보처리학회 2006 한국정보처리학회 학술대회논문집 Vol.13 No.2
본 논문에서는 분산 해쉬 테이블을 이용하는 P2P 시스템에서의 로드 밸런싱 문제를 다룬다. 또 한 기존의 로드 밸런싱 알고리즘에서 객체의 키 정보의 양을 기준으로 계산한 결과 대신 실제 환경에서의 네트워크 지연에 영향을 미치는 단위 시간 내의 객체의 검색량을 기준으로 로드를 계산함으로써 로드의 개념을 실제 환경에 맞게 재정의한다. 또한 재정의한 로드의 연속성이라는 특성을 고려하여 로드 밸런싱의 비용을 줄이기 위한 효율적인 로드 밸런싱 알고리즘을 제안한다.