• 제목/요약/키워드: vessel

검색결과 6,888건 처리시간 0.037초

암의 비대칭적 성장, 혈관생성 및 혈류역학에 대한 수치적 연구 (Numerical Research about Asymmetric Growth of Cancer, Angiogenesis and Hemodynamics)

  • 김유석;심은보
    • 대한기계학회:학술대회논문집
    • /
    • 대한기계학회 2007년도 춘계학술대회B
    • /
    • pp.2951-2954
    • /
    • 2007
  • Tumor hemodynamics in vascular state is numerically simulated using pressure node solution. The tumor angiogenesis pattern in our previous study is used for the geometry of vessel networks. For tumor angiogenesis, the equation that governed angiogenesis comprises a tumor angiogenesis factor (TAF) conservation equation in time and space, which is solved numerically using the Galerkin finite element method. A stochastic process model is used to simulate vessel formation and vessel. In this study, we use a two-dimensional model with planar vessel structure. Hemodynamics in vessel is assumed as incompressible steady flow with Newtonian fluid properties. In parent vessel, arterial pressure is assigned as a boundary condition whereas a constant terminal pressure is specified in tumor inside. Kirchhoff's law is applied to each pressure node to simulate the pressure distribution in vessel networks. Transient pressure distribution along with angiogenesis pattern is presented to investigate the effect of tumor growth in tumor hemodynamics.

  • PDF

설문분석을 통한 어선 비어선간 충돌사고에 관한 연구 (A Study on the Collision between Fishing Vessel and non Fishing Vessel using Questionnaire Analysis)

  • 박문갑;전영우;이유원
    • 수산해양교육연구
    • /
    • 제25권3호
    • /
    • pp.716-723
    • /
    • 2013
  • The postal or group questionnaire survey was conducted to inquire into the cause of collision between fishing vessel and non-fishing vessel targeting fishing vessel personnel(FVP), non-NFVP and a person involved in a marine accident. As a result, we could verify the root cause of collision, a negligence of lookout which noted overwork for FVP and careless for non-FVP. The cause of collision by inappropriate avoid action was poor communications for FVP and non-FVP. To reduce collision, we need to be trained to take a sharp lookout, a radio communication by VHF and the collision avoidance actions by early and substantial action to keep well clear. The results are expected to contribute for the reduction of collision and victims.

복합재 고압용기의 스마트 모니터링을 위한 FBG 센서의 삽입 적용성에 관한 연구 (Feasibility Study of Embedded FBG Sensors for the Smart Monitoring of High Pressure Composite Vessel)

  • 박상욱;박상오;김천곤
    • 한국복합재료학회:학술대회논문집
    • /
    • 한국복합재료학회 2005년도 춘계학술발표대회 논문집
    • /
    • pp.33-36
    • /
    • 2005
  • In this research, for the smart health monitoring of the hydrogen storage high pressure composite vessel, the feasibility study of an embedded fiber Bragg grating(FBG) sensor is carried out. To verify strain measurement in various temperature environment which is needed for the hydrogen pressure vessel, tensile test of a composite specimen with both an embedded FBG sensor and a strain gauge is made in low temperature. Before we try a real-size hydrogen storage pressure vessel, a small & cheap composite pressure vessel having the same structure is fabricated with embedded FBG sensors and tested. In the case of an aluminum liner inside the vessel, survivability of FBG sensors at the interface is lower than the other areas.

  • PDF

KSTAR 토카막용 저온용기 개발 (Development of the Cryostat Vessel for KSTAR Tokamak)

  • 허남일;김병철;홍권희;김근홍;신훈;박경호;박주식
    • 대한기계학회:학술대회논문집
    • /
    • 대한기계학회 2004년도 추계학술대회
    • /
    • pp.545-550
    • /
    • 2004
  • KSTAR cryostat is a 8.8 m diameter vacuum vessel that provides the necessary thermal barrier between the ambient temperature test cell and the supercritical helium cooled superconducting magnet providing the base pressure of 1 ${\times}$ $10^{-3}Pa$. The cryostat is a single walled vessel consisting of central cylindrical section and two end closures, a flat base structure with external reinforcements and a dome-shaped lid structure. The base structure has 8 equally spaced support legs anchored on the concrete base. The cryostat vessel design was executed to satisfy the performance and operation requirements. The major loads considered in the structural analysis were vacuum pressure, dead weight, electromagnetic load driven by plasma disruption, and seismic load. Based on the fabrication and inspection procedures for the vessel, cryostat vessel was fabricated and inspected. It was confirmed that the inspection results were acceptable.

  • PDF

Longitudinal Penetration of Water through the Vessel and Wood Fiber in Castanea crenata

  • Ahmed, Sheikh Ali;Chun, Su-Kyoung
    • 한국가구학회지
    • /
    • 제19권2호
    • /
    • pp.111-115
    • /
    • 2008
  • An experiment was conducted to know ultra-pure distilled water penetration depth through large vessel, small vessel, latewood fiber and earlywood fiber in longitudinal direction of Castanea crenata. In heartwood, latewood fiber transported water more than large and small vessel. While in sapwood, small vessel conduction depth was found the highest. Penetration depth of water after 15.0 seconds, no significant difference was observed among earlywood fiber, latewood fiber and earlywood vessel. Whilst in heartwood, no statistical difference was observed among earlywood fiber, latewood fiber and earlywood vessel. At the beginning, the speed of water penetration was high and then gradually decreased.

  • PDF

An Investigation of Thermal Margin for External Reactor Vessel Cooling(ERVC) in Large Advanced Light Water Reactors(ALWR)

  • Park, Jong-Woon;Jerng, Dong-Wook
    • 한국원자력학회:학술대회논문집
    • /
    • 한국원자력학회 1997년도 춘계학술발표회논문집(1)
    • /
    • pp.473-478
    • /
    • 1997
  • A severe accident management strategy, in-vessel retention corium through external reactor vessel cooling(ERVC) is being studied worldwide as a means to prevent reactor vessel failure following a core melt accident. An evaluation of feasibility of this ERVC for a large Advanced Light Water Reactor (ALWR) is presented. To account for the coolability of corium and metal in the reactor vessel, a thermal analysis is performed using an existing method. Results show that the peak heat flux along the inner surface of the reactor vessel lower head has a relatively smaller margin than a small capacity reactor such as AP600 in regards with the critical heat flux attainable at the outer surface of the reactor vessel lower head.

  • PDF

A Study on the Fuzzy Controller for an Unmanned Surface Vessel Designed for Sea Probes

  • Park, Soo-Hong;Kim, Jong-Kwon;Lee, Won-Boo;Jang, Cheol-Soon
    • 제어로봇시스템학회:학술대회논문집
    • /
    • 제어로봇시스템학회 2005년도 ICCAS
    • /
    • pp.586-589
    • /
    • 2005
  • Recently, the applications of unmanned system are steadily increasing. Unmanned automatic system is suitable for routine mission such as reconnaissance, environment monitoring, resource conservation and investigation. Especially, for the ocean environmental probe mission, many ocean engineers had scoped with the routine and even risky works. The unmanned surface vessel designed for sea probes can replace the periodic and routine missions such as water sampling, temperature and salinity measuring, etc. In this paper, an unmanned surface vessel was designed for ocean environmental probe missions. A classical and an adaptive fuzzy control system were designed and tested for the unmanned surface vessel. The design methodologies and performance of the surface vessel and fuzzy control algorithm were illustrated and verified with this unmanned vessel system designed for sea probes.

  • PDF

진동교반조에서의 액자유표면의 거동에 관한 연구 (A Study on the Behavior of Liquid Free Surface in a Shaking Vessel)

  • 이영세;김문갑
    • 한국산업융합학회 논문집
    • /
    • 제3권3호
    • /
    • pp.209-217
    • /
    • 2000
  • An attempt has been made to examine the highest liquid surface by means of measuring the movement of liquid free surface wave in the agitated vessel wall. Also, Relationship has been investigated between transition frequency, $N_z$ for behavior of liquid free surface and transition frequency for behavior of mass transfer coefficient in the agitated vessel wall. A surface wave is occured within agitated vessel, the highest height of wetted vessel wall, $h_w$ is coincided with the highest liquid surface, h. However the lowest height of wetted vessel, $h^*{_w}$ is not descended to lowest liquid free surface, $h^*$. The proposed model has been tested sucessfully for the behavior of liquid free surface.

  • PDF

선박 PMS를 위한 데이터 수집 미들웨어와 사용자 편의적 디스플레이연구 (A Research of Data Gathering Middleware and User Friendly Display for vessel PMS(Planned Maintenance System))

  • 이서정
    • 한국IT서비스학회지
    • /
    • 제12권2호
    • /
    • pp.335-348
    • /
    • 2013
  • Vessel PMS (Planned Maintenance System) is a paper and/or software based system to monitor vessel engine equipment including main propulsion, steering, auxiliary machinery and cargo handling information. This is one of mandatory survey for vessel introduced by IMO (International Maritime Organization). The planned maintenance as well as documentation must be performed according to a system to be approved by classification agencies. Recently, vessel owners have preferred software based systems to collect and preserve accurate data. However, not ship specific and not taking into account the user are said by end users as operational difficulties. To relieve these concerns, this research analyzes vessel PMS data, suggests a middleware to support automatic collection and design consideration of user interface.

DETAILED EVALUATION OF THE IN-VESSEL SEVERE ACCIDENT MANAGEMENT STRATEGY FOR SBLOCA USING SCDAP/RELAP5

  • Park, Rae-Joon;Hong, Seong-Wan;Kim, Sang-Baik;Kim, hee-Dong
    • Nuclear Engineering and Technology
    • /
    • 제41권7호
    • /
    • pp.921-928
    • /
    • 2009
  • As part of an evaluation for an in-vessel severe accident management strategy, a coolant injection into the reactor vessel under depressurization of the reactor coolant system (RCS) has been evaluated in detail using the SCDAP/RELAP5 computer code. A high-pressure sequence of a small break loss of coolant accident (SBLOCA) has been analyzed in the Optimized Power Reactor (OPR) 1000. The SCDAP/RELAP5 results have shown that safety injection timing and capacity with RCS depressurization timing and capacity are very effective on the reactor vessel failure during a severe accident. Only one train operation of the high pressure safety injection (HPSI) for 30,000 seconds with RCS depressurization prevents failure of the reactor vessel. In this case, the operation of only the low pressure safety injection (LPSI) without a HPSI does not prevent failure of the reactor vessel.