• 제목/요약/키워드: scale down

검색결과 840건 처리시간 0.031초

축소모형실험을 통한 콘크리트 충전 FRP 합성교각의 성능 평가 (Performance Evaluation of Scale-down Concrete Filled FRP Columns)

  • 염광수;이승혜;이영호;송재준;황윤국
    • 한국구조물진단유지관리공학회 논문집
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    • 제13권1호통권53호
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    • pp.135-144
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    • 2009
  • 본 연구에서는 현장타설과 프리캐스트 방식의 콘크리트 충진 FRP 교각의 성능평가 실험을 수행하였다. 8개의 축소모형 실험체에 대한 준정적 실험을 실시하였으며, 실험변수로는 FRP 두께, 콘크리트 강도, 횡방향 철근비, 직경을 선정하였다. 반복 횡하중에 대한 연성능력을 평가하고 각 시험체의 강성저하에 따른 감쇠비와 파괴양상 등을 비교하였다.

주택에서의 각 생활행위에 대응하는 조명환경에 관한 실험연구 (An Experiment on Lighting Environment for some Behavior in Housing)

  • 이선영
    • 한국주거학회논문집
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    • 제16권4호
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    • pp.65-71
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    • 2005
  • The present study performed subjective evaluation experiments using slides and scale down models in order to propose guidelines for lighting environment desirable for each behavior in the house. The evaluation measure was composed of 20 mood items and 15 behavior items. As for experiment methods, the slide experiment used SD method, and the scale down model experiment used Scheffe's paired comparison. The results of this study are as follows. 1) Desirable lighting environment for working and talking is active atmosphere. 2) Lighting environment desirable far relaxation is to heighten lighting contrast using candescent lamps and local lights. In other words, active atmosphere, which is desirable for working and talking, is not desirable for relaxation. 3) Lighting for working requires bright illuminance and high color temperature(6000k). 4) Lighting for relaxation requires somewhat low brightness regardless of color temperature. If the light is bright it is better to use lamps of low color temperature. 5) for conversation, bright illuminance is more desirable than dark one, and the most adequate color temperature is 4000K.

미세 엔진 운용성 검증 및 요소 기술 개발 (Fabrication and feasibility estimation of Micro Engine Component)

  • 이대훈;박대은;최권형;윤준보;권세진;윤의식
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2001년도 춘계학술대회논문집D
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    • pp.31-36
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    • 2001
  • As a part of micro engine development feasibility estimation was done through fabrication and test of down scaled combustor and MEMS fabricated spark electrode. In an experimental observation of the down scaled combustion phenomena where flame propagation was observed by optical method and pressure change in combustor which gives the information about the reaction generated thermal energy was recorded and analyzed. Optimal combustor scale was derived to be about 2mm considering increased heat loss effect and thermal energy generation capability. Through the fabrication and discharge test of MEMS electrode effects of electrode width and gap was investigated. Electrode was fabricated by thick PR mold and electroplating. From the result discharge voltage characteristic in sub millimeter scale electrode having thickness of $40{\mu}m$ was obtained. From the result base technology for design and fabrication of micro engine was obtained.

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타워형 태양열 흡수기의 열전달 특성 실험장치에 관한 연구 (Scale Down Design on Experiment Facility of the Water/Steam Receiver for Solar Power Tower)

  • 서호영;김종규;강용혁;김용찬
    • 한국신재생에너지학회:학술대회논문집
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    • 한국신재생에너지학회 2007년도 춘계학술대회
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    • pp.676-679
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    • 2007
  • This paper describes an experiment facility to measure the circulation characteristics of a water/steam receiver at various heat fluxes. The natural circulation type receiver was considered in this study. The experiment facility was designed to satisfy circulation balance with an appropriate scale down. As a result, riser tube inner diameter was 7.4 mm and water circulation was 0.319 kg/s. Downcomer tube inner diameter by circulation balance was 9.52 mm and the quality was from 0 to 0.23.

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1/2 축소된 원형교각의 GFRP 래핑 내진보강 (Seismic Retrofit of 1/2 Scale-down Circular RC Columns with GFRP Wrapping)

  • 염광수;최영민;이영호;권태규;김정호;황윤국
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2006년도 춘계학술발표회 논문집(I)
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    • pp.250-253
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    • 2006
  • This paper presents experimental studies on investigating the seismic retrofit performance of reinforced concrete circular columns with poor lap-splice details using GFRP wrapping. Four 1/2 scale-down model columns have been tested. The as-built column is expected to suffer brittle failure due to the bond failure of lap-spliced longitudinal reinforcement. The retrofitted columns using GFRP wrapping showed significant improvement of seismic performance.

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지표면에서 연속 전자파를 사용하는 지하 탐사용 안테나 설계에 관한 연구 (A study on the anntenna design for subsurface cw radar above the earth surface)

  • 박동국;류재우;라정웅
    • 전자공학회논문지A
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    • 제31A권12호
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    • pp.23-30
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    • 1994
  • In this paper, we present an antenna which can be used for subsurface continuous wave electromagnetic probing. Its input impedance and transmission coefficient of the two port scattering parameters, S$_{21}$, are calculated numerically and the numerical results are compared with measured values from laboratory scale-down experiment. Scale-down experiemtn results using this antenna show that we can detect a metallic pipe, which has 0.8 cm in diameter and buried at a depth of 5.7cm in saline solution, in frequency range from 200 MHz to 1000 MHz.

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A Calibration Method for Six-Accelerometer INS

  • Hung Chao-Yu;Lee Sou-Chen
    • International Journal of Control, Automation, and Systems
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    • 제4권5호
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    • pp.615-623
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    • 2006
  • The gyroscope free strap-down INS is composed only of accelerometers. Any gyroscope free INS navigation error is deeply affected by the accuracy of the sensor bias, scale factor, orientation and location error. However these parameters can be found by calibration. There is an important research issue about a multi-position calibration method in this paper. It provides a novel method to find the error parameters for the six-accelerometer INS. A superior simulation is shown that the multi-position calibration can find the specifications of a six-accelerometer INS in laboratory. From these parameters the six-accelerometer INS could apply in realistic navigation.

축척모형 실험에 의한 고속전철 방음벽용 소음저감 장치 (Noise reduction of noise barrier with noise reducer for high speed train by using scale down model test)

  • 정성수;전병수;나희승;김준엽;양신추
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2001년도 추계학술대회논문집 II
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    • pp.647-652
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    • 2001
  • A noise reduction of noise barrier for high speed train was measured by using scale down model test. A selected types of noise barriers were simple vertical barrier, interference type barrier with plate, interference type barrier with cylindrical pipes. On experiment, in order to make similar present test lane condition, reduced train model and multiple noise sources were considered. As a result. interference type noise barrier with cylindrical pipes is most effective than other barriers. A present height of noise barrier which is established in a test lane is not high enough for reducing patograph noise.

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KUH 주로터 축소 블레이드 설계 (Design of KUH Main Rotor Small-scaled Blade)

  • 김도형;김승호;한정호
    • 항공우주기술
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    • 제8권1호
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    • pp.32-41
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    • 2009
  • 본 연구에서는 한국형기동헬기(KUH) 주로터 블레이드의 축소 설계를 수행하였다. 축소 모델은 공력하중, 익단 와류 및 소음원 측정 시험을 위해 설계되었다. 실제 로터와 동일한 공력 하중을 모사하기 위하여 마하스케일링 기법이 적용되었다. 마하스케일 모델은 블레이드의 익단 마하수가 동일하며, 정규화된 진동수 또한 동일하다. 즉, 마하스케일된 모델은 공력하중 및 구조동역학적 과점에서 상사된 모델이다. 공기역학적 축소과정은 외형 치수의 축소와 회전수의 증가를 통해 완료된다. 구조동역학적 측면에서는 블레이드 단면 설계를 통해 생성된 강성 및 관성 분포가 실제 로터의 회전고유진동수 분포를 나타내는지 확인하는 과정을 통해 완료된다. 본 연구에서는 국내에서 수급 가능한 복합재 프리프레그를 이용한 블레이드 단면 설계를 수행하고, 설계된 모델의 동역학적 특성을 고찰하였다.

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사석구조물(捨石構造物)의 안정성(安定性)에 관한 수리모형(水理模型)의 축척효과(縮尺効果) (Scale Effects of Stability Parameters in the Hydraulic Model Tests of Rubble Mound Coastal Structures)

  • 류청로
    • 대한토목학회논문집
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    • 제7권3호
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    • pp.111-119
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    • 1987
  • 해안구조물(海岸構造物)의 안정성(安定性)과 사면상(斜面上)의 반사파(反射波), run-up, run-down 등 흐름특성(特性)에 대한 모형(模型)의 축척효과(縮尺効果) 발생(發生) 메카니즘과 그 제어(制御) 방법(方法)을 7종(種)의 축척모형(縮尺模型)에 의해 실험적(實驗的)으로 연구(硏究)하였다. 그 결과(結果), 종래(從來)의 많은 연구자(硏究者)들이 소홀히 해 왔던 구조물(構造物) 내부(內部)의 침투류(浸透流) 특성(特性)의 상사(相似) 여부(如否)가 축척효과(縮尺効果) 발생(發生)의 가장 중요(重要)한 요인(要因)임을 지적(指摘)하였다. 해안구조물(海岸構造物) 가운데서 특히 투과성(透過性) 구조물(構造物)의 축척효과(縮尺効果) 제어(制御)를 위해서는 피복층(被覆層), filter층(層), 피복층(被覆層)에 가까운 core부(部)의 침투류(浸透流) Reynolds수(數)가 각각(各各) Re > $2{\times}10^4$, $Re_f$ > $3{\times}10^3$, $Re_c$ > $1{\times}10^3$인 조건(條件)을 만족하도록 구조물(構造物) 각(各) 층(層)의 축척(縮尺)을 결정(決定)하는 것이 바람직함을 강조(强調)하였다.

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