• Title/Summary/Keyword: circulation rate

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백화점 매장계획을 위한 VMD와 고객동선의 상관관계에 관한 분석적 연구 (A Study on the Correlation between Customer's Circulation and VMD in Planning the Interior of Department Stores)

  • 최영신;차소란;임채진
    • 한국실내디자인학회논문집
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    • 제32호
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    • pp.121-130
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    • 2002
  • At the large commercial facilities, people try to grasp a customer's needs as the marketing strategies for effective management and maximization of profits as well as the primary purpose for functional and effective spatial plan. In planning the interior of each department, they try to provide the image of the interior environment corresponding to customer's emotional needs. And this kind of efforts also have been improved as visual merchandising strategies based on the transmission of visual information. This study is to examine the correlation among customer's behavior, circulation and VMD by gasping their shopping patterns at the department stores based on the spatial and emotional approach to form an environmental image of each department. The researcher focused on time, speed and rate of shopping that show customer's behavioristic characteristics and examine the factors to have an influence on decision making. With the result, this study proposes the primary data and evidence for MD planning, circulation planning and VMD planning of each department.

단열재 조건에 따른 원자로용기 외벽냉각 성능 예비분석 (A Preliminary Assessment on ERVC Performance Depending on Insulation Conditions)

  • 최동현;장윤석
    • 한국압력기기공학회 논문집
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    • 제19권1호
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    • pp.36-43
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    • 2023
  • Lots of researches have been conducted on in-vessel retention (IVR) to prevent or mitigate severe accident in nuclear power plants. Various methodologies were proposed and the external reactor vessel cooling was selected as a part of promising IVR strategy. In this study, the strategy is strengthened by enhancing the natural circulation performance through the adoption of insulation in the reactor cavity. A thermal analysis was carried out based on an assumed accident scenario and its results were used as boundary conditions for subsequent seven flow analysis cases. By comparing the natural circulation performance, effects of annular gaps and insulation shapes on the mass flow rate and flow velocity were quantified. The improvement in cooling performance can be reflected in actual design via detailed assessment.

전방순환동맥류 발생 위치에 대한 혈류량 및 분지각의 영향 및 동맥류 발생 전후의 유동 변화에 관한 수치해석 연구 (NUMERICAL ANALYSIS FOR THE EFFECT OF BLOOD FLOW RATE AND BIFURCATION ANGLE ON THE LOCATION OF ANTERIOR CIRCULATION ANEURYSM AND THE CHANGE OF BLOOD FLOW CHARACTERISTICS AFTER ANEURYSM FORMATION)

  • 김소윤;노경철;유홍선
    • 한국전산유체공학회지
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    • 제16권4호
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    • pp.64-71
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    • 2011
  • Cerebral aneurysm mostly occurs at a bifurcation of the circle of Willis. When the cerebral aneurysm is ruptured, a disease like subarachnoid hemorrhage and stroke is caused and this can be even deadly for patients. Generally it is known that causes of the intracranial aneurysm are a congenital deformity of the artery and pressure or shear stress from the blood flow. A blood flow pattern and the geometry of the blood vessel are important factors for the aneurysm formation. Research for several hemodynamic indices has been performed and these indices can be used for the prediction of aneurysm initiation and rupture. Therefore, the numerical analysis was performed for hemodynamic characteristics of the blood flow through the cerebral artery applying the various bifurcation angle and flow rate ratio. We analyze the flow characteristics using indices from the results of the numerical simulation. In addition, to investigate the flow pattern in the aneurysm according to the bifurcation angle and the flow rate ratio, we performed the numerical simulation on the supposition that the aneurysm occurs.

전방순환동맥류 발생 위치에 대한 혈류량 및 분지각의 영향 및 동맥류 발생 전후의 유동 변화에 관한 수치해석 연구 (NUMERICAL ANALYSIS FOR THE EFFECT OF BLOOD FLOW RATE AND BIFURCATION ANGLE ON THE LOCATION OF ANTERIOR CIRCULATION ANEURYSM AND THE CHANGE OF BLOOD FLOW CHARACTERISTICS AFTER ANEURYSM FORMATION)

  • 김소윤;노경철;유홍선
    • 한국전산유체공학회:학술대회논문집
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    • 한국전산유체공학회 2011년 춘계학술대회논문집
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    • pp.161-168
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    • 2011
  • Cerebral aneurysm mostly occurs at a bifurcation of the circle of Willis. When the cerebral aneurysm is ruptured a disease like subarachnoid hemorrhage and stroke is caused and this can be even deadly for patients. Generally it is known that causes of the intracranial aneurysm are a congenital deformity of the artery and pressure or shear stress from the blood flow. A blood flow pattern and the geometry of the blood vessel are important factors for the aneurysm formation. Research for several hemodynamic indices has been performed and these indices can be used for the prediction of aneurysm initiation and rupture. Therefore, the numerical analysis was performed for hemodynamic characteristics of the blood flow through the cerebral artery applying the various bifurcation angle and flow rate ratio. We analyze the flow characteristics using indices from the results of the numerical simulation. In addition, to investigate the flow pattern in the aneurysm according to the bifurcation angle and the flow rate ratio, we performed the numerical simulation on the supposition that the aneurysm occurs.

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고선양(高線量) 방사선(放射線)이 백혈구(白血球) 수명(壽命)에 미치는 영향(影響) (Effects of High Dose Irradiation on The Leukocyte Life Span)

  • 고주환;정인용;김용규
    • Journal of Radiation Protection and Research
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    • 제9권2호
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    • pp.67-75
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    • 1984
  • As a part of studies on acute effects of high dose irradiation the present report was carried out to evaluate the changes of the leukocyte life span in the Newzealand white male rabbits by a single whole body exposure to gamma rays from $^{60}Co$ teleirradiation unit. The exposure was done in dose levels of 100, 300, 550 and 1,000 rad to each experimental group of 10 rabbits. The life span and apparent half survival time of leukocytes, and the elution rate of leukocytes in the circulating blood were measured by McMillan method using $^{51}Cr$. 1. As a critical indicator of radiation hazards of the Newzealand male rabbits, the LD 50/30 and LD 100/30 after whole body exposure was estimated as 550 and 1,000 rads respectively. 2. The life span of leukocyte in the circulation after irradiation was slightly shortened in the 100 rad irradiated group, as compared with the unirradiated control group, but markedly shortened in the 300, 550 and 1,000 rads irradiated group. 3. After irradiation, decrease of leukocyte half survival time in the circulation showed the same pattern as that of leukocytes life span. 4. As the irradiation doses increased, the elution rate of $^{51}Cr$ loss from $^{51}Cr$ tagged leukocytes in the circulation were markedly increased gradually. 5. The life span shortening of leukocytes in the circulation after irradiation seems to occure by two processes of senescence acceleration and early destruction.

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타워형 태양열 발전 흡수기의 열유속에 따른 수순환 특성 연구 (Water Circulation Characteristics of a Water/Steam Receiver for Solar Power Tower System at Various Heat Fluxes)

  • 서호영;김종규;강용혁;김용찬
    • 한국태양에너지학회 논문집
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    • 제28권2호
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    • pp.1-9
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    • 2008
  • This paper describes water circulation characteristics of a water/steam receiver at various heat fluxes. The water/steam receiver for a solar tower power system is a natural circulation type. Experimental conditions of water and steam were set at a pressure of 5 bar and temperature of $151.8^{\circ}C$. The experimental device for the water/steam receiver consisted of a steam drum, upper/lower header, riser tubes, and downcomer tube. The experiments were conducted by varying heat fluxes in terms of mass flow rate in each riser tube. However, the total mass flow rate on the riser tubes was fixed at 217.4 g/s. For the uniform heat flux, while the water temperature of the steam drum and upper header were kept at steady state, the temperature of the lower header was fluctuated. For the non-uniform heat flux, while the temperature of the steam drum was kept steady state, the temperature difference increased in the right and left side of the upper header, and the temperature of the lower header was fluctuated.

새로운 순환방식을 적용한 동전기 정화기술에 의한 오염토양내의 납제거 (A New Circulation Method for Electrokinetic Remediation of Soil Contaminated with Lead)

  • 이현호;백기태;양지원
    • 한국지하수토양환경학회지:지하수토양환경
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    • 제8권1호
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    • pp.9-16
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    • 2003
  • 동전기 정화기술을 이용한 오염토양 정화시에 단점으로 지적되는 $10^{+}$에 의한 전기삼투 흐름의 유속 저하와 $OH^{-}$에 의한 중금속의 침전 현상을 감소시키기 위하여 새로운 방법이 제시되었다. 이는 양극과 음극의 전해질을 직접 순환시킴으로서 양극과 음극의 전해질 pH를 조절하여 동전기 정화기술을 적용한 토양 정화시에 오염토양 복원을 위한 조업기간의 연장, 전기경사 증가율의 감소, 그리고 대상 중금속인 납 제거율을 향상시킬 수가 있었다. 이는 전해질의 pH 조절을 통하여 토양 pH를 조절함으로써 가능하였다. 또한 전해질 순환공정을 적용할 경우 유출수가 발생하지 않아 일반적으로 동전기 정화기술의 적용시의 단점으로 지적되는 유출수의 2차 처리에 대한 문제점을 해결하였으며, 유출수의 발생이 제거됨에 따라 조업시에 사용되는 전해질의 사용량 또한 획기적으로 감소시킬 수가 있었다.

Experimental research on the mechanisms of condensation induced water hammer in a natural circulation system

  • Sun, Jianchuang;Deng, Jian;Ran, Xu;Cao, Xiaxin;Fan, Guangming;Ding, Ming
    • Nuclear Engineering and Technology
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    • 제53권11호
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    • pp.3635-3642
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    • 2021
  • Natural circulation systems (NCSs) are extensively applied in nuclear power plants because of their simplicity and inherent safety features. For some passive natural circulation systems in floating nuclear power plants (FNPPs), the ocean is commonly used as the heat sink. Condensation induced water hammer (CIWH) events may appear as the steam directly contacts the subcooled seawater, which seriously threatens the safe operation and integrity of the NCSs. Nevertheless, the research on the formation mechanisms of CIWH is insufficient, especially in NCSs. In this paper, the characteristics of flow rate and fluid temperature are emphatically analyzed. Then the formation types of CIWH are identified by visualization method. The experimental results reveal that due to the different size and formation periods of steam slugs, the flow rate presents continuous and irregular oscillation. The fluid in the horizontal hot pipe section near the water tank is always subcooled due to the reverse flow phenomenon. Moreover, the transition from stratified flow to slug flow can cause CIWH and enhance flow instability. Three types of formation mechanisms of CIWH, including the Kelvin-Helmholtz instability, the interaction of solitary wave and interface wave, and the pressure wave induced by CIWH, are obtained by identifying 67 CIWH events.

펠레트 충전층 전극 반응기의 특성 -흑연 펠레트 전극- (The Behavior of Pellet Packed-bed Electrodes Reactor -Graphite Pellet Electrode-)

  • 김학준
    • 공업화학
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    • 제3권4호
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    • pp.657-662
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    • 1992
  • 흑연 펠레트 전극으로 채워진 복극성 고정상 충전층 전극 반응기에 대하여 등가회로 모델을 적용하여 반응기에 가해진 전류에 대한 복극성 전극에 흐른 Faradaic 전류의 비를 전해액의 전도도와 순환속도에 대하여 검토하였다. 전전류에 대한 Faradaic 전류의 비는 인가전류(전압)에 따라 증가하며, 전해액 전도도와 액 순환속도의 증가에 따라 감소하였다.

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굴참나무 낙엽의 Fire Whirl 특성에 관한 실험연구 (Experimental Study on the Fire Whirl Characteristics of Oriental Oak Leaves)

  • 홍기배;이재하;배승용;유홍선
    • 한국안전학회지
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    • 제24권4호
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    • pp.17-21
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    • 2009
  • The fire whirl occurring in the urban and/or wildland fire is generated by the instabilities of atmosphere. The fire whirl is a rare phenomenon, but highly destructive because it has high inhalation and lift force. In this study, experimental study is performed with oriental oak leaves, for investigating of the fire whirl characteristics occurred in wildland fire. As a result of experiment, the circulation intensity increases as increasing of the induced air velocity, and then the fire whirl occurs. Also, the heat release rate and flame height increase 22% and 18% in highest circulation.