• 제목/요약/키워드: general circulation

검색결과 484건 처리시간 0.026초

Hybrid Coronary Artery Revascularization for Takayasu Arteritis with Major Visceral Collateral Circulation from the Left Internal Thoracic Artery

  • Sim, Hyung Tae;Kim, Jeong-Won;Yoo, Jae Suk;Cho, Kwang Ree
    • Journal of Chest Surgery
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    • 제50권2호
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    • pp.105-109
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    • 2017
  • Coronary arterial involvement in Takayasu arteritis (TA) is not uncommon. Herein, we describe a case of TA with celiac trunk and superior mesenteric artery occlusion combined with coronary artery disease. Bilateral huge internal thoracic arteries (ITAs) and the inferior mesenteric artery provided the major visceral collateral circulation. After percutaneous intervention to the right coronary artery, off-pump coronary artery bypass grafting for the left coronary territory was done using a right ITA graft and its large side branch because of its relatively minor contribution to the visceral collateral circulation.

The simulation study on natural circulation operating characteristics of FNPP in inclined condition

  • Li, Ren;Xia, Genglei;Peng, Minjun;Sun, Lin
    • Nuclear Engineering and Technology
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    • 제51권7호
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    • pp.1738-1748
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    • 2019
  • Previous research has shown that the inclined condition has an impact on the natural circulation (natural circulation) mode operation of Floating Nuclear Power Plant (FNPP) mounted on the movable marine platform. Due to its compact structure, small volume, strong maneuverability, the Integral Pressurized Water Reactor (IPWR) is adopted as marine reactor in general. The OTSGs of IPWR are symmetrically arranged in the annular region between the reactor vessel and core support barrel in this paper. Therefore, many parallel natural circulation loops are built between the core and the OTSGs primary side when the main pump is stopped. and the inclined condition would lead to discrepancies of the natural circulation drive head among the OTSGs in different locations. In addition, the flow rate and temperature nonuniform distribution of the core caused by inclined condition are coupled with the thermal hydraulics parameters maldistribution caused by OTSG group operating mode on low power operation. By means of the RELAP5 codes were modified by adding module calculating the effect of inclined, heaving and rolling condition, the simulation model of IPWR in inclined condition was built. Using the models developed, the influences on natural circulation operation by inclined angle and OTSG position, the transitions between forced circulation (forced circulation) and natural circulation and the effect on natural circulation operation by different OTSG grouping situations in inclined condition were analyzed. It was observed that a larger inclined angle results the temperature of the core outlet is too high and the OTSG superheat steam is insufficient in natural circulation mode operation. In general, the inclined angle is smaller unless the hull is destroyed seriously or the platform overturn in the ocean. In consequence, the results indicated that the IPWR in the movable marine platform in natural circulation mode operation is safety. Selecting an appropriate average temperature setting value or operating the uplifted OTSG group individually is able to reduce the influence on natural circulation flow of IPWR by inclined condition.

공연시설의 공간구성별 동선체계에 관한 기초적 연구 - 오페라 전문극장을 중심으로 - (A Basic Study on the Circulation System by the Spatial Composition of Performing art Facilities - Focusing on Dedicated Opera House -)

  • 한수호;고재민;임채진
    • 한국실내디자인학회:학술대회논문집
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    • 한국실내디자인학회 2006년도 춘계학술발표대회 논문집
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    • pp.183-188
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    • 2006
  • In general, performing facilities consist of various functional groupings. The functional groupings should be arranged, in relation to each other, depending on the circulation of users in a space. The performing culture in Korea has been rapidly progressed in recent years. However, compared to the superior examples of foreign performing facilities, it still needs improvements and systematic research. In this study, the functional groupings of general performing facilities as well as the circulation patterns of users will be analyzed. From the results of this study, a circulation system for each spatial composition will be suggested for the performing facilities to be constructed in the future.

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Validation of Ocean General Circulation Model (FMS-MOM4) in Relation with Climatological and Argo Data

  • Chang, You-Soon;Cho, Chang-Woo;Youn, Yong-Hoon;Seo, Jang-Won
    • 한국지구과학회지
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    • 제28권5호
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    • pp.545-555
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    • 2007
  • Ocean general circulation model developed by GFDL on the basis of MOM4 of FMS are examined and evaluated in order to elucidate the global ocean status. The model employs a tripolar grid system to resolve the Arctic Ocean without polar filtering. The meridional resolution gradually increases from $1/3^{\circ}$ at the equator to $1^{\circ}$ at $30^{\circ}N(S)$. Other horizontal grids have the constant $1^{\circ}$ and vertical grids with 50 levels. The ocean is also coupled to the GFDL sea ice model. It considers tidal effects along with fresh water and chlorophyll concentration. This model is integrated for a 100 year duration with 96 cpu forced by German OMIP and CORE dataset. Levitus, WOA01 climatology, serial CTD observations, WOCE and Argo data are all used for model validation. General features of the world ocean circulation are well simulated except for the western boundary and coastal region where strong advection or fresh water flux are dominant. However, we can find that information concerning chlorophyll and sea ice, newly applied to MOM4 as surface boundary condition, can be used to reduce a model bias near the equatorial and North Pacific ocean.

박물관의 순회형식과 관람동선에 관한 연구 (A Study on the Visitor's Circulation of Exhibition Space in Museum)

  • 신미경;임채진
    • 한국실내디자인학회논문집
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    • 제5호
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    • pp.24-29
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    • 1995
  • Entering into the modern society, the discussion on the role played by and the social position held by museums are forced to take into account the visitors, that is, the general public being real consumers of culture in accord-ance with the enlargement of the study of the visi-tors. The study of a museum has been developed with priori-ty given to the architectural study and exhibition space, but the study of the form of circulation of visitors using the museum is believed to have put an emphasis on the rough form of circulation on the basis of the general and basic theory and the particulars while the discussions on the more concrete method of study and its application are excluded as a basis of approaching in details to exhi-bition plans or producing plans. Consequently, the purpose of the study is to under-stand the problems in the form of circulation in the exist-ing exhibition rooms, and to infer the planning principles of interior design with priority given to the problems in space composition, details of exhibitions, the points in method, recognitions by visitors and the relation of path line as a way of resolving the problem.

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기후변화에 따른 대구지역 지하배수 전망 (Future subsurface drainage in the light of climate change in Daegu, South Korea)

  • 은코모제피 템바;정상옥
    • Current Research on Agriculture and Life Sciences
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    • 제30권2호
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    • pp.97-104
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    • 2012
  • Over the last century, drainage systems have become an integral component of agriculture. Climate observations and experiments using General circulation models suggest an intensification of the hydrologic cycle due to climate change. This study presents hydrologic simulations assessing the potential impact of climate change on subsurface drainage in Daegu, Republic of Korea. Historical and Long Ashton Research Station weather generator perturbed future climate data from 15 general circulation models for a field in Daegu were ran into a water management simulation model, DRAINMOD. The trends and variability in rainfall and Soil Excess Water ($SEW_{30}$) were assessed from 1960 to 2100. Rainfall amount and intensity were predicted to increase in the future. The predicted annual subsurface drainage flow varied from -35 to 40 % of the baseline value while the $SEW_{30}$ varied from -50 to 100%. The expected increases in subsurface drainage outflow require that more attention be given to soil and water conservation practices.

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공공도서관의 주제별 자료 이용 현황 분석: 서울특별시 A구 산하 공공도서관을 중심으로 (A Study on Collection Use of an Public Libraries Focused of the Clustering Analysis of Circulation Statistics of the Seoul Borough A Library Users)

  • 김완종
    • 정보관리학회지
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    • 제31권3호
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    • pp.353-369
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    • 2014
  • 본 연구는 서울특별시 A구 산하 9개 도서관 이용자들의 대출 기록을 모두 조사하여 주제별 장서이용 행태를 분석하고 주제 분야 간 어떠한 연관성을 지니고 있는가를 알아보는데 그 목적이 있다. 이를 위하여 2006년 6월부터 2014년 6월까지 발생한 2,723,115건의 대출 기록을 수집하여 분석하였다. 한국십진분류(KDC)에 따라 총류(000)부터 역사(900)까지 10개 대분류와 총류(000)부터 전기(990)까지 100개 중분류로 나누어 주제별 대출빈도를 분석하였으며, 도서관 이용자들의 대출기록 기록을 중분류에 따른 상관계수에 근거한 군집분석을 통하여 주제별 연관성을 분석하였다.

단과대학별 도서관 장서 활용 현황 분석을 위한 대출데이터 기반 대출지수 비교 (Analysis of Circulation Measures based on Circulation Data of Colleges in a University)

  • 최상희;이재윤
    • 정보관리학회지
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    • 제35권4호
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    • pp.125-140
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    • 2018
  • 대출데이터는 대학도서관에 축적된 중요한 데이터로서 도서관 장서개발이나 서비스 개선에 활용될 수 있는 중요한 데이터이다. 이 연구는 대출빈도를 기반으로 한 다양한 대출관련지수를 비교분석하여 지수별 특성을 파악한 후 도서관 운영에 적용할 수 있는 타당성을 평가하고자 하였다. A 대학도서관의 10개 단과대학별 대출데이터를 대상으로 비교분석한 지수는 대출빈도, 대출엔트로피, 대출 h-지수, 대출주제차별지수 등 총 4개의 지수이다. 이 지수들을 적용하여 단과대학별 대출현황을 분석하였고 단과대학별로 나타나는 대출주제의 특성을 표하는 각 지수의 특성을 비교 분석하였다. 분석 결과 대출 엔트로피는 여러 대학이 공통으로 선호하는 주제를 표현하는 성향이 있는 것으로 나타났다. 반면 대출주제차별지수는 특정대학에서만 특화되어 대출되는 주제를 표현하는 성향이 있는 것으로 나타났다.

Gas Bubble Driven Circulation Systems에서의 이상유동 특성의 시뮬레이션 (A Simulation on the Two-Phase Flow Characteristics in Gas Bubble Driven Circulation Systems)

  • 최청렬
    • 한국시뮬레이션학회논문지
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    • 제7권2호
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    • pp.17-32
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    • 1998
  • The flow fields in Gas Bubble Driven Circulation Systems were numerically analyzed. In various gas flow rate and bubble size, the flow characteristics were predicted. Eulerian-Eulerian approach was used for the formulation of both the continuous and dispersed phases. The modification of the general purpose computer program PHOENICS code was employed to predict the mean flow fields, turbulent characteristics, gas dispersion, volume fraction. The predicted shows very satisfactory agreement with experimental results for all regions of ladle. The results are of interest in the design and operation of wide variety of material processing.

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Pedagogical Mathematica Platform Visualizing the Coriolis Effects in 3-Cell Atmospheric Circulation Model

  • Kim, Bogyeong;Yun, Hee-Joong
    • Journal of Astronomy and Space Sciences
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    • 제31권1호
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    • pp.91-99
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    • 2014
  • The atmospheric flow in the 3-Cell model of global atmosphere circulation is described by the Lagrange's equation of the non-inertial frame where pressure force, frictional force and fictitious force are mixed in complex form. The Coriolis force is an important factor which requires calculation of fictitious force effects on atmospheric flow viewed from the rotating Earth. We make new Mathematica platform to solve Lagrange's equation by numerical analysis in order to analyze dynamics of atmospheric general circulation in the non-inertial frame. It can simulate atmospheric circulation process anywhere on the earth. It is expected that this pedagogical platform can be utilized to help students studying the atmospheric flow understand the mechanisms of atmospheric global circulation.