• 제목/요약/키워드: circulation

검색결과 5,401건 처리시간 0.031초

도시특성 요인의 다중선형회귀 분석을 이용한 물순환상태추정모델 개발 (Development of water circulation status estimation model by using multiple linear regression analysis of urban characteristic factors)

  • 김영란;황성환;이연선
    • 상하수도학회지
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    • 제34권6호
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    • pp.503-512
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    • 2020
  • Identifying the water circulation status is one of the indispensable processes for watershed management in an urban area. Recently, various water circulation models have been developed to simulate the water circulation, but it takes a lot of time and cost to make a water circulation model that could adapt the characteristics of the watershed. This paper aims to develop a water circulation state estimation model that could easily calculate the status of water circulation in an urban watershed by using multiple linear regression analysis. The study watershed is a watershed in Seoul that applied the impermeable area ratio in 1962 and 2000. And, It was divided into 73 watersheds in order to consider changes in water circulation status according to the urban characteristic factors. The input data of the SHER(Similar Hydrologic Element Response) model, a water circulation model, were used as data for the urban characteristic factors of each watershed. A total of seven factors were considered as urban characteristic factors. Those factors included annual precipitation, watershed area, average land-surface slope, impervious surface ratio, coefficient of saturated permeability, hydraulic gradient of groundwater surface, and length of contact line with downstream block. With significance probabilities (or p-values) of 0.05 and below, all five models showed significant results in estimating the water circulation status such as the surface runoff rate and the evapotranspiration rate. The model that was applied all seven urban characteristics factors, can calculate the most similar results such as the existing water circulation model. The water circulation estimation model developed in this study is not only useful to simply estimate the water circulation status of ungauged watersheds but can also provide data for parameter calibration and validation.

BIM과 그래프를 기반으로 한 건물 동선의 표현과 분석 접근방법 - UCN의 확장형인 MRP 그래프의 제안 - (An Approach to the Graph-based Representation and Analysis of Building Circulation using BIM - MRP Graph Structure as an Extension of UCN -)

  • 김지수;이진국
    • 한국건설관리학회논문집
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    • 제16권5호
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    • pp.3-11
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    • 2015
  • 본 연구는 BIM을 활용한 그래프 기반의 동선 표현과 분석 접근 방법 제안을 목적으로 한다. 접근 방법의 제안을 위해 건물 동선 관련 요구사항 파악과 공간 네트워크, BIM에 관한 선행연구를 분석하였다. 또한, 본 연구는 선행연구인 UCN(Universal Circulation Network)을 기반으로 연구를 진행하였으며, 본 연구를 통해 UCN에 추가적으로 고려해야 할 사항을 파악하고 이를 확장하였다. 본 연구에서는 UCN을 기반으로 두 가지 관점에서 동선의 표현과 분석 접근 방법을 제안하고자한다: 1) UCN의 그래프 기반 동선 분석의 주요 요소를 파악한다, 2) 국내 건축법 등의 요구사항을 적용하여 UCN을 재구성한다. 결과적으로, 본 연구에서는 출구에서 가장 먼 점 (MRP) 기반의 동선 표현과 가상공간에서의 동선 분석이 추가적으로 제안되었다.

동영상 유통시스템 기반요소에 관한 고찰 (A Study on Basic Element for Video Content Circulation System)

  • 김성원
    • 한국문헌정보학회지
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    • 제42권1호
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    • pp.33-44
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    • 2008
  • 인터넷의 대중화와 IT 기술의 발전에 따라 인터넷을 통한 동영상 자료의 활용 및 유통이 활성화되고 있다. 성장하는 유기체로서 정보 유통의 중심이 되어야 할 도서관의 입장에서는 새로운 정보원으로서 동영상 정보의 유통에 관심을 기울어야 하는 시점이다. 본 고에서는 이러한 배경에서 동영상 정보자료의 유통을 위한 시스템 구축의 기반을 제시하고자 하는 목적으로 동영상 유통시스템 구축과 관련된 제반 사항을 검토하였다. 이를 위해 인터넷을 통한 동영상 유통현황과 유통활성화의 기술적 기반이 되는 관련 기술 발전현황을 살펴보았다. 또한 동영상 정보자료의 유통을 위한 시스템의 각 구성요소를 소개하였고 실제 구축과정에서 고려해야 할 기반 요소들을 검토하였다. 본 연구를 통해 소개된 내용을 기반으로 실제 동영상 유통시스템의 구축을 검토하는 도서관 실무에 도움이 될 수 있기를 기대한다.

장시간의 체외순환이 생체에 미치는 영향 (Influences of Prolonged Extracorporeal Circulation on Organ Function in Dogs)

  • 김의윤
    • Journal of Chest Surgery
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    • 제7권1호
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    • pp.73-78
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    • 1974
  • Influences on organ function were studied in animals during prolonged extracorporeal circulation with a bubble type of oxygenator. More than six hours of total cardiopulmonary bypass was performed under mild hypothermia by means of an extracorporeal circulation system in five dogs. Obtained results were summarized as follows. 1. The renal function was not so impaired seriously until four hours of extracorporeal circulation. However, there was more serious impairment of renal function in this study when extracorporeal circulation was carried out for a period of five hours or more. 2. There was gradual hepatic damage during extracorporeal circulation and the damage was more significant after bypass for a period of five to six hours. 3. There was a significant decrease in serum K during bypass, irrespective of the pump oxygenator prime with a high K solution. The reason for this is complex and due to many factors, however, it was evidently related to serum glucose levels during extracorporal circulation.

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학교건축의 복도(複道) 계획에 관한 연구 (A Study on the Architectural Design of Student Circulation Space)

  • 이화룡
    • 교육녹색환경연구
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    • 제3권1호
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    • pp.24-34
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    • 2003
  • The architectural design of student circulation space has a pronounced influence on the educational function of a school building. Recent curriculum and new teaching methods have required the sufficient space provided for circulation and various circulation spaces in a school building, such as elevator, pilotis, bridge, atrium, deck, lobby and locker room. However excessive circulation space is wasteful form the standpoint of both initial investment and operation. This study aims to investigate new circulation patterns and functions, and to propose the adequate size in planning a school corridor. For this purpose, it explores the recent trends of the corridor planning represented in the excellent school facilities in 2002. and analyzes the newly-added functions In the school corridor : architectural in-between space, dwelling space for ordinary activities, space for educational media and auxiliary learning space. This research recommends that the corridor width be carefully planned according to the supposed functions in order to achieve the efficiency in the design of school facilities.

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박물관 대공간(Major Space)의 동선구조 형식과 특성에 관한 연구 (A Study on the Type and Characteristics of the Circulation in Major Space of Museums)

  • 박세민;정성욱
    • 한국실내디자인학회:학술대회논문집
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    • 한국실내디자인학회 2008년도 춘계학술발표대회 논문집
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    • pp.209-213
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    • 2008
  • This study is intended to propose a plan index that can be used in the early stage of a museum design based on theoretical review of a major space of a museum including its spatial division, functions and roles. The scope of the study includes functions and roles of circulation in a major space based on precedent studies. The spatial range is limited to a major space among exhibition spaces in a museum. This study analyzes overseas 14 museums. In terms of methodology, the study analyzes circulation in a descriptive way only In the focusing on floor plan and section composition. The results of this study are as follows. First, vertical elements should be critically considered in a circulation plan for functional performance of dimensional circulation distribution in a major space. Second, a plan by location of vertical and horizontal moving elements related to a major space affects a circulation relation more than a connection type between a major space and an exhibition area.

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사각 단면 채널에서의 자연순환 유동에 관한 연구 (Natural Circulation Flow Investigation in a Rectangular Channel)

  • 하광순;김재철;박래준;김상백;홍성완
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2007년도 춘계학술대회B
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    • pp.3086-3091
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    • 2007
  • When a molten corium is relocated in a lower head of a reactor vessel, the ERVC (External Reactor Vessel Cooling) system is actuated as coolant is supplied into a reactor cavity to remove a decay heat from the molten corium during a severe accident. To achieve this severe accident mitigation strategy, the two-phase natural circulation flow in the annular gap between the external reactor vessel and the insulation should be formed sufficiently by designing the coolant inlet/outlet area and gap size adequately on the insulation device. For this reason, one-dimensional natural circulation flow tests were conducted to estimate the natural circulation flow under the ERVC condition of APR1400. The experimental facility is one-dimensional and scaled-down as the half height and 1/238 rectangular channel area of the APR1400 reactor vessel. As the water inlet area increased, the natural circulation mass flow rate asymptotically increased, that is, it converged at a specific value. And the circulation mass flow rate also increased as the outlet area, injected air flow rate, and outlet height increased. But the circulation mass flow rate was not changed along with the external water level variation if the water level was higher than the outlet height.

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혐기성 유동층 생물막 반응기에서 순환유속 증가에 따른 층공극률 및 유기성 폐수 처리특성에 관한 연구 (A Study on the characteristics of the bed porosity and organic wastewater treatment with the circulation velocity in the anaerobic fluidized bed biofilm reactorA Study on the characteristics of the bed porosity and organic wastewater treatment with the circulation velocity in the anaerobic fluidized bed biofilm reactor)

  • 김재우;안재동
    • 환경위생공학
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    • 제10권3호
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    • pp.1.1-15
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    • 1995
  • This study was performed to estimate the characteristics of the organic wastewater treatment and bed porosity with the circulation velocity in the anaerobic fluidized bed biofilm reactor. The results were as follows; 1. With Increasing circulation velocity the fluidized bed expanded smooth and with increasing initial particle volume the fluidized bed was increased. 2. With increasing circulation velocity the gasproduction was increased, but at 1.Scnt/sec of circulation velocity AFBBR showed the highest value of methane production rate per removed COD. Therefore, for the purpose of economical operation in AFBBR, 1.5cm/sec of circulation velocity was optimum 3. The microorganisms were colonized in the crevice of the media. 4. On fluidization, COD, VA,55 profiles with the reactor height were not showed. In conclusion, AFBBR suit the organic wastewater treatment's purpose, and at 1.5cm/sec of circulation velocity the system is economical in an energy Point of view.

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대형아트의 상품구성에 따른 동선체계의 특징에 관한 연구 - 공간구조와 공간연출의 특성을 기준으로 - (A Study on the Circulation System on accordance with the Merchandise in Discount Store - with reference to the spatial configuration and the VMD pattern -)

  • 김세은;문정묵
    • 한국실내디자인학회논문집
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    • 제17권6호
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    • pp.137-142
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    • 2008
  • Since mid 1990s, the domestic market in Korea has been changing drastically especially in the field of discount stores. The competition among this market is more severe and the consuming pattern is also changed. This study is to examine the correlation between the customer's circulation and the spatial configuration by using Space Syntax and VMD pattern through the MD plan of each floor in Discount store. Throughout this study, it tries to find out the Quantitative analysis among three factors - the customer's circulation, spatial configuration and VMD investigation. The pattern of customer's circulation appears differently according to the identity of customer and store layout, but with the result, customer's circulation system is in accordance with the floor layout in the store. In result of the study, the circulation of the customer was found to have a close relationship with spatial structure that is composed by the MD pattern in a discount store in the area of food section. Also, the circulation system in the rest area except food section is more affected by the VMD pattern rather than spatial structure.

The Impact of Southern Ocean Thermohaline Circulation on the Antarctic Circumpolar Current Transport

  • 김성중;이방용
    • 지구물리
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    • 제9권4호
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    • pp.291-299
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    • 2006
  • The observed ocean barotropic circulation is not completely explained by the classical wind-driven circulation theory. Although it is believed that the thermohaline forcing plays a role in the ocean barotropic circulation to some degree, how much the thermohaline forcing contributes to the barotropic circulation is not well known. The role of thermohaline circulation driven by changes in temperature and salinity in the Southern Ocean (SO) water masses on the Antarctic Circumpolar Current (ACC) transport is investigated using a coupled ocean - atmosphere - sea ice - land surface climate system model in a Last Glacial Maximum (LGM) context. Withthe implementation of glacial boundary conditions in a coupled model, a substantial increase in the ACC transport by about 75% in 80 years of integration and 25% in the near LGM equilibrium is obtained despite of the decreases in the magnitude of wind stresses over the SO by 33% in the transient time and 20% in the near-equilibrium. This result suggests that the increase in the barotropic ACC transport is due to factors other than the wind forcing. The change in ocean thermohaline circulation in the SO seems to play a significant role in enhancing the ACC transport in association with the change in the bottom pressure torque.

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