• 제목, 요약, 키워드: Performance test load

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철도교용 IT거더의 피로특성 (Fatigue characteristics of the IT girder for railroad)

  • 최상현;이창수
    • 한국재난정보학회 논문집
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    • v.6 no.2
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    • pp.119-130
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    • 2010
  • In designing a railroad bridge, the fatigue is one of the main factors to be considered for ensuring safe operation. Especially, for a new type of a structural member, which has not been adopted to railroad bridges, the fatigue performance should be checked. In this paper, the fatigue characteristics of an IT girder are examined. The IT girder is a new type of a prestressed concrete girder which has two prestressed H-beams in the top of the girder to give the girder additional sectional capacity. To obtain the fatigue performance, a 10m IT girder specimen is designed, and a repeated load test is performed by applying the load cyclically two million times. The magnitude of the repeated load is determined considering the stress level under the service condition. During the test, static load tests are performed to identify the stiffness degradation. The fatigue performance of the girder is checked according to the Japanese and the CEB-FIB design codes. The fatigue test result shows that the IT girder satisfies both design codes.

벨로우즈를 이용한 반복 하중부과장치의 개발 및 성능시험 (Performance Tests and Development of the Cyclic Load Device Using a Bellows)

  • 최명환;조만순;박승재;김봉구
    • 대한기계학회논문집A
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    • v.31 no.9
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    • pp.903-909
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    • 2007
  • A fatigue capsule is one of the special capsules to investigate the fatigue characteristics of the nuclear materials during an irradiation test in a research reactor, HANARO. In this study, the performance test and the preliminary fatigue test results by using a cyclic load device newly developed for a fatigue capsule are described. In order to obtain the characteristics such as a realization and a controllability of the periodic wave shape and the relationship between the pressure and the load, a spring and rigid bar specimens are used. The fatigue test for the 316L stainless steel specimen with 1.8mm in diameter and 12.5mm in gage length is also performed under the same conditions as the temperature($550^{\circ}C$) of the specimen during irradiation tests. As a result of the test, the fracture of the specimen occurs at a total of 70,120 cycles(about 12 days), and the displacement in this case is 2.02 mm. It is expected that these results will be used for determining test conditions and a comparison of the in-pile fatigue test results.

과전류 부하에서 5상 농형 유도전동기의 정수 특성 (Parameters Estimation Characteristics of Five-Phase Squirrel-Cage Induction Motor within Over Current Load)

  • 김민회
    • 조명전기설비학회논문지
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    • v.29 no.7
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    • pp.38-46
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    • 2015
  • This paper propose a variable parameter estimations for variable over current load of five-phase squirrel-cage induction motor(IM) to servo control system. In order to high performance control of AC motor using a field oriented control(FOC) and direct torque control(DTC) algorithm, there are required precise motor parameters for slip calculation, flux observer, controller gain, torque command of current components, rotor position, speed estimation, and so on. We are suggest a analyzed estimation results of the motor parameters that developing five-phase squirrel-cage IM have a stator of concentrated winding for experimental within variable over current load at rated input frequency. There are results of stator winding measurement, no-load test, locked-rotor test, variable over current load test, and estimated parameters of equivalent circuits using manufactured experimental apparatus by IEEE Standard Test Procedure for Polyphase Induction Motors and Generators 112-2004.

전력회수 능력을 갖는 전압원 컨버터-인버터 세트로 구성된 부하모의장치 (Load Simulator with Power-Recovery Capability Based on Voltage Source Converter-Inverter Set)

  • 배병열;한병문
    • 전력전자학회:학술대회논문집
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    • pp.76-80
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    • 2004
  • This paper describes a load simulator with power-recovery capability, which is based on the voltage source converter-inverter set. The load simulator described in this paper can save the electric energy that should be consumed to test the operation and performance of the distributed generation system and the power quality compensator. The load simulator consists of a converter-inverter set with a DSP controller for system control and PWM pulse generation. The converter operates as a universal load to model the linear load and the non-linear load, while the inverter feed the energy back to the power source with harmonic compensation. The load simulator can be widely used in the lab to test the performance of the distributed generation system and the power quality compensator.

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전력회수 능력을 갖는 전압원 컨버터-인버터 세트로 구성 된 부하모의 장치 (Load Simulator with Power-Recovery Capability Based on Voltage Source Converter-Inverter Set)

  • 배병열;한병문
    • 대한전기학회논문지:전기기기및에너지변환시스템부문B
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    • v.54 no.4
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    • pp.181-187
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    • 2005
  • This paper describes a load simulator with power-recovery capability, which is based on the voltage source converter-inverter set. The load simulator described in this paper can save the electric energy that should be consumed to test the operation and performance of the distributed generation system and the power quality compensator. The load simulator consists of a converter-inverter set with a DSP controller for system control and PWM pulse generation. The converter operates as a universal load to model the linear load and the non-linear load, while the inverter feed the energy back to the power source with harmonic compensation. The load simulator can be widely used in the lab to test the performance of the distributed generation system and the power quality compensator.

Influence of different fatigue loads and coating thicknesses on service performance of RC beam specimens with epoxy-coated reinforcement

  • Wang, Xiao-Hui;Gao, Yang;Gao, Run-Dong;Wang, Jing;Liu, Xi-La
    • Computers and Concrete
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    • v.19 no.3
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    • pp.243-256
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    • 2017
  • Epoxy-coated reinforcing bars are widely used to protect the corrosion of the reinforcing bars in the RC elements under their in-service environments and external loads. In most field surveys, it was reported that the corrosion resistance of the epoxy-coated reinforcing bars is typically better than the uncoated bars. However, from the experimental tests conducted in the labs, it was reported that, under the same loads, the RC elements with epoxy-coated reinforcing bars had wider cracks than the elements reinforced with the ordinary bars. Although this conclusion may be true considering the bond reduction of the reinforcing bar due to the epoxy coating, the maximum service loads used in the experimental research may be a main reason. To answer these two phenomena, service performance of 15 RC beam specimens with uncoated and epoxy-coated reinforcements under different fatigue loads was experimentally studied. Influences of different coating thicknesses of the reinforcing bars, the fatigue load range and load upper limit as well as fatigue load cycles on the mechanical performance of RC test specimens are discussed. It is concluded that, for the test specimens subjected to the comparatively lower load range and load upper limit, adverse effect on the service performance of test specimens with thicker epoxy-coated reinforcing bars is negligible. With the increments of the coating thickness and the in-service loading level, i.e., fatigue load range, load upper limit and fatigue cycles, the adverse factor resulting from the thicker coating becomes noticeable.

육미지황탕 투여가 운동 지구력 향상에 미치는 영향 (Effects of Yukmijihwang-tang on Maximal Exercise Performance)

  • 배기상;박진한
    • 동의생리병리학회지
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    • v.29 no.6
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    • pp.498-502
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    • 2015
  • Yukmijihwang-tang (YM) is a well-known prescription to treat kidney inflammation on Korea. However, the effects of YM on maximal exercise performance (MEP) is not-well investigated. In this study, we aimed to evaluate the effects of YM on MEP using forced swimming test (FST) model. Mice were largely divided into three group; a non-swimming group, saline treated-swimming load test group, and YM treated-swimming load group. Swimming load test groups were re-divided into swimming control group (Control), YM fed group (YM). YM was administrated orally for 2 weeks before FST. After FST, immobility time, oxygen consumption was measured by physiological test, and serum was collected for biochemical analysis. FST induced MEP identified by increased immobility, oxygen consumption, and biochemical factors. Immobility time was significantly reduced by YM treatment compared with control group. Oxygen consumption was also significantly reduced by YM treatment. The increase on lactic acid and lactate dehydrogenase after FST was inhibited by YM treatment. In addition, consumption of energy source (free fatty acid, and triglyceride) and recovery of energy was enhanced by YM treatment after FST. In conclusion, YM inhibited the elevation of immobility time, oxygen consumption, and biochemical factors after FST. YM could be used as a beneficial agents to enhance maximal endurance exercise performance and an effective ergogenic aid in exercise training.

웹서버 성능 향상을 위한 로드 발란서 성능 연구 (Load Balancer Performance Testing and Analysis for Improving Web Server Performance)

  • 장동원;조평동
    • 한국정보통신학회:학술대회논문집
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    • pp.125-128
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    • 2001
  • 본 고에서는 웹 서버 팜(farm)의 성능을 향상시키기 위해서 사용되는 로드 발란서(load balancer)의 성능을 측정하고 분석하였다. 로드 반란서는 입력되는 트래픽을 서버 팜의 각 서버에 고르게 분산시켜서 클라이언트의 접속 요구를 최대한 수용해서 전체적인 서비스 풀질을 향상시킨다. 본 고에서는 로드 발란서가 초당 최대 수용할 수 있는 접속 요구를 측정하고 이때 로드 발란싱(load balancing)이 서버 광의 각 서버로 고르게 이루어졌는지 측정한다.

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웹서버 성능 향상을 위한 로드 발란서 성능 연구 (Load Balancer Performance Testing and Analysis for Improving Web Server Performance)

  • 장동원;조평동
    • 한국정보통신학회논문지
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    • v.5 no.6
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    • pp.1073-1077
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    • 2001
  • 본 고에서는 웹 서버 팜(farm)의 성능을 향상시키기 위해서 사용되는 로드 발란서(load balancer)의 성능을 측정하고 분석하였다. 로드 발란서는 입력되는 트래픽을 서버 팜의 각 서버에 고르게 분산시켜서 클라이언트의 접속 요구를 최대한 수용해서 전체적인 서비스 품질을 향상시킨다. 본 고에서는 로드 발란서가 초당 최대 수용할 수 있는 접속 요구를 측정하고 이때 로드 발란싱(load balancing)이 서버 팜의 각 서버로 고르게 이루어 졌는지 측정한다.

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초고층에서의 현장타설말뚝 재하시험방법 고찰 (The Study of Load Test Method for In-Site Casting Pile In High Rise Building.)

  • 김대학;홍영길;한성무;구웅회;박찬덕
    • 한국지반공학회:학술대회논문집
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    • pp.385-392
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    • 2008
  • Modern city have had a lot of high-rise building in high standards and multi-level performance. Using of city space reach better stages by using integration. These skyscraper have increased working load on ground. that building is efficiently designed for that soil capacity is well applied. With material side, big size pile, high strength concrete and high strength steel is used for that getting enough lobby space and resisting load increased of high-rise building. limit load test and load transmitted test can make soil capacity optimized. By the way, method of measuring pile capacity is more advanced and bigger. pile type applied by high rise building have underground excavation space, also reflect regional soil property and have some fact reviewed. A lot of high rise building recently is built as land mark in Seoul, Busan and Incheon. about method of measuring capacity of foundation pile, example of construction field is compared and reviewed.

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