• 제목/요약/키워드: Side ratio

검색결과 2,037건 처리시간 0.024초

An Experimental Investigation of Side-Orifice Effects on Pressure Drop for Single-Phase Flow

  • Seo, Kyong-Won;Chun, Moon-Hyun;Nam, Ho-Yun;Park, Seok-Ki;Lee, Yong-Bum
    • 한국원자력학회:학술대회논문집
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    • 한국원자력학회 1996년도 추계학술발표회논문집(1)
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    • pp.295-300
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    • 1996
  • To investigate the effects of the side-orifice on the pressure drop for single-phase flow, a series of experiments have been carried out with 16 different downstream test sections with various combinations of side-orifice shapes, different numbers of side-orifices, and different arrangements of the side-orifice using water as a working fluid. From the measurements of the pressure drop and the flow rate, the pressure loss coefficient of the side-orifice(s) has been evaluated. Based on the total number of 529 present data, an empirical correlation for the pressure loss coefficient has been developed in terms of Reynolds number and geometric parameters, such as area ratio, equivalent diameter, leading edge, and average width of side-orifice.

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PIV에 의한 정면에 삼각주를 가진 정방형주 주위의 유동장 특성분석 (Investigation of flowfield characteristics of a square prism having a front triangular prism by PIV)

  • 노기덕;김재동
    • Journal of Advanced Marine Engineering and Technology
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    • 제40권3호
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    • pp.205-209
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    • 2016
  • 본 연구는 상류측에 작은 삼각주를 가진 정방형주의 유동장 특성을 정방형주 한 변의 길이에 대한 삼각주의 폭비 및 정방형주 전면에서부터 삼각주 후면까지의 간격을 변수로 하여 PIV를 이용한 가시화실험으로 파악한 것이다. 그 결과를 요약하면 다음과 같다. 정방형주 후류측 스트로할 수는 항력감소율과 같은 특성을 나타내었는데, 간격비가 증가할수록 증가한 후 감소하는 특성을 보였다. 삼각주를 설치한 경우 정방형주 상류측과 하류측에 정체영역이 나타났으며, 그 정체영역의 크기는 정방형주의 상류측은 삼각주의 폭비가 클수록 증가하는데 비해, 하류측은 오히려 감소했다.

Correlation between Weight Bearing Ratio and Functional Level for Development of Pressure Sensor Biofeedback in Stroke Patient

  • Moon, Young;Kim, Mi-Sun;Choi, Jong-Duk
    • 대한물리의학회지
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    • 제9권3호
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    • pp.315-324
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    • 2014
  • PURPOSE: This study aimed to determine the correlation of weight bearing ability at the affected side with balance and gait abilities for the development of pressure biofeedback based equipment to stroke patients. METHODS: This study included 35 patients with stroke patient. The tests were conducted to determine the weight bearing ratio while pushing a step forward the affected side, static balance ability using the total length of COP(Center of pressure), sway velocity of COP, COP velocity at the X and Y axis. Functional reaching test (FRT), berg balance scale (BBS) were used to assess the dynamic balance ability and timed up and go test (TUG), 10m walk test (10mWT) were used assess the gait ability respectively. In order to determine the correlation between measured variables, bivariate correlation analysis was conducted. RESULTS: A significant correlation of the weight bearing ratio were shown with COP total length and velocity(r=-.34), Y-axis velocity(r=-.39), FRT(r=.42), BBS(r=.54), TUG (r=-.39), and 10m walking test (r=-.42). CONCLUSION: This study result showed that as patients with stroke had more weight bearing ratio at the affected side, not only their static and dynamic balance abilities increased more but also functional gait ability improved more. These results mean that, to improve stroke patients' static, dynamic balance ability and gait ability, weight bearing training with the affected side foot placed one step forward necessary for gaits are important.

단순악관절 잡음군에서 좌/우 진동 감별방법 연구 (Study for discriminating method of origin side vibration from non-symptomatic clicking group)

  • 정다운;강동완
    • 구강회복응용과학지
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    • 제32권1호
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    • pp.38-46
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    • 2016
  • 목적: 단순악관절 진동군에서 좌/우 진동 중 유의한 진동의 감별법을 연구하는 것이다. 연구 재료 및 방법: 단순악관절 진동만을 갖고 있고 측두하악관절 질환의 제 증상이 없는 단순악관절 진동그룹 30명의 60개 관절에서 44쌍의 진동을 기록하였고 대상자의 인지와 검사자의 촉진, JVA 검사 결과를 비교하였다. JVA로 기록된 진동의 주파수 스펙트럼, 진동파형 시간차 위상변위 분석, 수치 분석을 통해 좌/우 진동 중 유의한 진동을 감별하였다. 결과: JVA 분석결과 양측성 진동은 한 건도 없었으며 유의한 편측 진동은 42개로 감별되었다. 시간차 위상변위를 보이는 것은 11쌍이었고 이 중 한 쌍을 제외한 모든 진동에서 전달된 측의 진동이 발생측 진동보다 진동 총에너지(total integral) 값은 더 작고 > 300 / < 300 ratio는 같거나 더 큰 특징을 보이는 것을 관찰하였다. 또한 진동 총에너지 값이 10 이하로 작고 시간차 위상변위를 보이지 않아 좌/우 감별의 근거가 모호한 나머지 진동 모두에서 진동 총에너지 값이 더 작은 쪽의 > 300 / < 300 ratio가 더 큼을 관찰하여 이를 좌/우 감별의 근거로 삼을 수 있었다. 결론: JVA로 좌/우 진동 중 유의한 진동을 감별하기 위해서는 주파수 스펙트럼, 시간차 위상변위 및 수치 분석 등이 모두 고려되어야 한다.

사상체질별 안면의 거리 각도 비율 특성 (Characteristics of Distance, Angle and Ratio among the Face Point on Photo in Sasang Constitutional Medicine)

  • 장은수;김윤정;김성훈;주종천
    • 사상체질의학회지
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    • 제22권2호
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    • pp.37-47
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    • 2010
  • 1. Objectives: We aimed to derive constitutional facial characteristics with front and side picture of the people in this study 2. Methods: Through November 2007 to July 2009, we obtained front and side face photograph data of 715 male/female constitution confirmed subjects within the age range of 10-80 from 19 oriental medical facilities in the country. According to sex, we divided the subjects into two groups, real constitution group and non-constitution group. We analyzed significant variables of distance, angle and ratio of facial point through unpaired T-test. 3. Results: There are different significant variables according to Sasang Constitution and even though they are much different between sex, the interpretation of the meaning of those variables are similar with the written characteristics of ancient Writing. The face size of the Taeeumin is bigger than that of the non-Taeeumin, and especially they have long length from mouth to mandible angle. Soeumin have small jaw area, long philtrum and narrow facial feature like egg. Soyangin has developed forehead and glabella, short jaw, long eye side. Taeyangin has developed forehead, weak nose especially side end of nose, long eye side. 4. Conclusions: Sasang Constitutional facial characteristics are different between man and woman but there are much similarity with the facts as known on the interpretation of significant variables characteristics.

초고층 건물의 각주형 단면에 대한 공력 불안정 진동 및 풍진 저감 효과에 관한 실험적 연구 (Reducing Effect of Wind-induced Vibration on Rectangular Model of Super-Highrise Building with Length of Corners Cutting)

  • 정영배
    • 한국강구조학회 논문집
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    • 제13권3호
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    • pp.301-311
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    • 2001
  • 내풍설계에 있어서, 아스펙트비가 6정도인 초고층 건물의 각주형 단면의 바람에 의한 공력 불안정 진동 또는 갤로핑 진동이 발생할 수 있다. 본 연구에서는 등류에서 아스펙트비 6정도이고 변장비가 1/4간격으로 1에서 2까지의 초고층 건물의 각주형 단면에대한 공력불안정 진동과 갤로핑 진동에 대해 실험적으로 고찰하였다. 실험 결과, 등류시 코너 컷이 없는 경우가 코너 컷을 가진 초고층 건물의 각주형 단면에 비해 공력 불안정 진동이 커지는 경향이 있으며, 또한 갤로핑 진동도 나타났다. 따라서, 코너 컷에 의해 각주형 초고층 건물에서의 공력 불안정 진동은 효과적으로 저감되었다.

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Thermal Effluent through Extruded Side Channel

  • Yoon, Tae-Hoon;Yook, Woon-Soo;Yi, Young-Kon
    • Korean Journal of Hydrosciences
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    • 제6권
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    • pp.67-79
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    • 1995
  • The reattachment of buoyant efflluent to a shore in a crossflow is investigated experimentally. The effluent is prodeced by discharging heated water through a projected side channel into a confined crossflow of the same depth. In the projecting effluent, the size of recirculating region, which is formed by deflected thermal plume on the lee of the effluent, tends to increase, but the maximum temperature decreases in the direction of the crossflow and it has more uniform transverse spreading compared to non-projected type. The heat flux across the crossflow is found to be independent of the projceted length of the side channel under relatively high buoyancy flux on the contrary to low buoyancy flux. The reattachment of th effluent can be specified by both velocity ratio and densimetric Froude number, whereas only the velocity ratio is governing factor to the reattachment of the effluent in the case of non-projecting type.

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레이저 용접 테일러드 블랭크의 기본 성형특성 I : 인장변형 특성 (Forming Characteristics of Laser Welded Tailored Blanks I : Tensile Deformation Characteristics.)

  • 박기철;한수식;김광선;권오준
    • 소성∙가공
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    • 제7권1호
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    • pp.23-35
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    • 1998
  • In order to analyze the tensile deformation characteristics of laser welded tailored blanks. laser welded blanks of different thikness and strength combinations were prepared and tensile tests were done. The tensile elongation along the direction perpendicular to weld line of laser welded blanks was reduced as increasing the deformation restraining force (strength X thicknes) ratio between two welded sheets and fracture occurred at weaker side of base sheets if void ration of welded sheets and fracture occurred at weaker side of base sheets if void ratio of weld section was less than 45% The tensile elongation along weld line reached above 90% of the elongation of base material if welding was done perfectly. Total elongation along the direction perpendicular to weld line was able to be predicted by force equilibrium and power law behavior of base sheets and it was related with the deformation of stronger sheet and formability of weaker side.

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Design Method for the LCL Filters of Three-phase Voltage Source PWM Rectifiers

  • Guo, Xizheng;You, Xiaojie;Li, Xinran;Hao, Ruixiang;Wang, Dewei
    • Journal of Power Electronics
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    • 제12권4호
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    • pp.559-566
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    • 2012
  • A new design method for the LCL filters of three-phase voltage source PWM rectifiers is presented in this paper. Based on the single-phase harmonic equivalent model, the harmonic voltage of the rectifier side is calculated to design the LCL filter parameters by an iterative algorithm, in which the resonance frequency $f_{res}$ and the ratio r between the grid-side inductance and the rectifier-side inductance are selected as known constants. The design criteria and process are introduced and the influence on the design result by the value of the resonance frequency $f_{res}$, ratio r is analyzed. Finally an example (600V, 500kW) is tested by simulation and experiment to verify the validity of the new design method.

고층건축물의 비틀림방향 변동풍력의 특성에 관한 실험적 연구 (Wind tunnel test study on verifying the characteristics of torsional fluctuating wind force of rectangular tall buildings)

  • 하영철;김동우;길용식
    • 유체기계공업학회:학술대회논문집
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    • 유체기계공업학회 2006년 제4회 한국유체공학학술대회 논문집
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    • pp.101-104
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    • 2006
  • This study aims at verifying characteristics of torsional fluctuating moment coefficient and power spectral density, which is needed to estimate torsional response of tall buildings. In order to estimate characteristics, the wind tunnel tests have been conducted on 52 types aero-elastic model of the rectangular prisms with various aspects ratios, side ratios and surface roughness in turbulent boundary layer flows. In this paper, characteristics of torsional fluctuating wind force are briefly discussed and then these results were mainly analyzed as a function of the aspects ratios and side ratios of buildings.

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