• Title/Summary/Keyword: Comparison of Measurement Method

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3-Dimensional Precision Measurement of Spacecraft Structure Test Model (위성체 구조시험 모델의 3차원 정밀 측정)

  • 윤용식;이중엽;조창래;이상설
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2001.04a
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    • pp.131-134
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    • 2001
  • The three-dimensional precision measurement technology for industry product of middle and/or large scale has been developed. Theodolite measurement system which is one of the technology is widely used in aerospace industry. This paper describes measurement method and results for spacecraft structure test model by using the measurement system. And structural stability for STM is desribed through the comparison between design values and measured values.

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Comparison of Antenna Parameters of R-/S-Band Standard Gain Horn Antennas

  • Kang, Jin-Seob;Kim, Jeong-Hwan;Park, Jeong-Il
    • Journal of electromagnetic engineering and science
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    • v.15 no.4
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    • pp.224-231
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    • 2015
  • A comparison of the antenna parameters for R-band (1.7-2.6 GHz) and S-band (2.6-3.95 GHz) standard gain horn antennas has been performed by the Korea Research Institute of Standards and Science (KRISS), together with seven domestic participants from private companies and public institutions. Its purpose, as a proficiency test program of the 'Antenna Measurement Club' of KRISS, was to check equivalences in antenna parameter measurements between KRISS and the participants, particularly in the R-/S-band, to support antenna manufacturers and end users in Korea. The measurement parameters of this comparison are the power gain, radiation pattern, and reflection coefficient of the traveling standards for R-/S-band pyramidal standard gain horn antennas. The comparison used a gain comparison method and an extrapolation method to measure the power gain of the two traveling standards; the radiation patterns were measured in the far-field region of the transmitting and receiving antennas.

The Comparison Between Blind and Normal Children in Standing Position (시각장애 아동과 정상 아동의 선자세 균형 비교)

  • Kim Chung-sun;Lee Jeong-soon
    • The Journal of Korean Physical Therapy
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    • v.15 no.1
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    • pp.119-154
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    • 2003
  • In this paper, the proprioceptive sensitivity was compared by Foot-Hand task method and the effect of the proprioceptive sensitivity and auditory to the standing position between blind and normal children was measured using BPM for 56 children in 7, 8, 9 and 10 years old. There are three measurement methods are used for BPM : Rest, Forward Looking, 'Sound' position. The following conclusions were obtained from the above measurements. 1. In comparison of proprioceptive sensitivity between blind and normal children, there is no significant difference(p > .05). There is no significant difference in comparison of each age group and also there is no difference in each gender group(p > .05). 2. In comparison of standing position measurement between blind and normal children, there is any difference (p > .05) in three measurement(Rest, Forward Looking, 'Sound' position) but there is no significant difference in each gender difference(p > .05). There is any difference between Rest and 'Sound' position of blind children, also there is any difference between Forward Looking and ' Sound ' position, rest and 'Sound' position of normal children(p > .05). 3. There is no significant difference of correlation between proprioceptive sensitivity test and standing position measurement in Pearson correlation coefficient(p > .05).

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P018 Comparison between Cutoff Probe and Langmuir Probe: Focused on Measurement Technique Error

  • Gwon, Jun-Hyeok;Kim, Dae-Ung;Yu, Sin-Jae;Sin, Yong-Hyeon
    • Proceedings of the Korean Vacuum Society Conference
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    • 2014.02a
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    • pp.235.1-235.1
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    • 2014
  • Precise measurement of plasma parameters including density and temperature is the most essential part for understanding plasma characteristics. To persue more accurate measurement, it is very important to understand the intrinsic error of the measurement method. In this paper, we performed the plasma measurement with different method; langmuire probe and cutoff probe. Both measurement technology are known to be exactly correlate with etch other. We conducted the four set of same experiments process by diffrent persons to observe the intrinsic error based on measurement tools. As a result, the cutoff probe is relatively reliable then the Langmuir probe. This difference is analyzed to be intrinsic since it cames from the inevitable error such as manufacturing of probe tip. From this study, we sure that it is good decision to choose cutoff probe as repeatable measurement independent with intrinsic human factor.

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A Standard Method for Progress Measurement in a Petrochemical Plant EPC Project (석유화학 플랜트 EPC 사업의 진도율 산정표준의 제안)

  • Cho, Hong-Yeon;Yoo, Hoseon
    • Plant Journal
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    • v.7 no.4
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    • pp.77-87
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    • 2011
  • In proportion to continuing growth of overseas plant market and the trend of its mega scale of the project, the importance of management is significantly emphasized for the successful execution of the project. And it is recognized that progress control is the most important management item amongst the others in the management. Progress control is importance of progress measurement for performance measurement and process control of project, but it is hardly obtainable securing the objectivity in the progress measurement since the progress measurement are being applied differently in accordance with the project conditions and the experience level of the person in charge for the progress control. This study has conducted as following to propose a standard method for progress measurement in a petrochemical plant protect. Domestic and overseas plant projects are investigated variously with the applied method of progress measurement, and the deduced problem of progress measurement. And then standard method for progress measurement of engineering, procurement, construction and commissioning has been proposed according to comparison and analysis of practices in domestic & overseas plant project, procedures for progress control in the globally reputed petrochemical client, company rules and recommendation of the expert in progress control.

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Analysis and Comparison of Flow Rate Measurements Using Various Discharge Measuring Instrument and ADCP (다양한 유량 측정기기와 ADCP를 이용한 유량 비교 분석)

  • Ji, Ju-Yeon;Park, Seung-Yong;Lee, Gwang-Woo;Park, Gyeong-Min;Hwang, Soon-Hong;Kim, Dong-Ho;Lee, Young-Joon
    • Journal of Environmental Science International
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    • v.22 no.2
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    • pp.251-257
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    • 2013
  • Discharge data examine the process of hydrologic cycle and used significantly in water resource planning and irrigation and flood control planning. It makes high quality discharge data, they carry out research on standard and method of discharge measurement, and equipment improvement. Now various flow meters are utilized to make discharge data in Korea. However, accuracy of equipment and exprerimental research data from measurement are not enough. ADCP(Acoustic Doppler Current Profiler) have been introduced and utilized for flow measurements since the end of 1980's. ADCP flow method is a formal method for flow measurement can easily applyd to relatively large rivers gradually recognized. This equipment can measure the non-contact three-dimensional velocity and water depth data very quickly and efficiently. Also, spatial and temporal resolution of the data is more accurate than any other flow measurement methods which measure flow rate by velocity - area measurement method. In this paper, the velocity is measured using various flow meter and verified the effectiveness by applying from the ADCP in Geum-river. Various flow meters which are med for discharge measurements are VALEPORT002, FLOW TRACKER, PRICE AA and ADCP. The average of five times flow measurement result by ADCP was $10.412m^3/s$, with a standard deviation of 0.68. The repeat test by ADCP and comparison between ADCP and other flow devices to verify the most import factor, flow measurement accuracy. In the result, repeat test of the ADCP showed similar values, flow values were similar to other velocity device results and the average error is 7.7%.

A Design of Simple and Precision Direction Finder with a Combination of an Amplitude Measurement and Phase Measurement

  • Lim Joong-Soo
    • International Journal of Contents
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    • v.1 no.2
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    • pp.35-38
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    • 2005
  • This paper describes a design of simple and precision direction finder that can be adapted to shipboard or mobile vehicles used for Electronic support measure, ELINT and radio signal monitoring systems. The direction finding technology has improved with monolithic integrated circuit, linear array antennas, and interferometer. Interferometer uses the phase-comparison principle and has a good direction finding accuracy but it has an ambiguity problem. We suggest a simple ambiguity solver using phase-comparison technology with amplitude-comparison principle. The direction finding device that has been designed by the suggested method has 0.7 degree RMS error in azimuth angle and 0.6 degree RMS error in elevation angle in 0.5 - 2.0 GHz.

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Comparison of laser technology & strain gauge application technology for measurement of interaction force between wheel and rail (차륜/레일 작용력 측정을 위한 레이저기술과 스트레인게이지 응용기술 비교)

  • Ham Young-Sam;Chung Woo-Jin;Sea Jung-Won
    • Proceedings of the KSR Conference
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    • 2004.06a
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    • pp.219-223
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    • 2004
  • Korea Railroad Research Institute(KRRI) propelled sensing and measurement techniques development for measure of Lateral Force and Vertical Force With Italy to international cooperation research project for laser technology for measurement of wheel/rail interaction force. In this paper, we compared the laser technology for measurement of wheel/rail interaction force with the existing method. And then, we suggests interaction force measurement system procedure of hereafter.

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Revised PPC Measurement Method considering Interfering Float Weight of Task

  • Jung-Sook Yun;Hyung-il Kim;Jung-Ho Yu;Chang-Duk Kim
    • International conference on construction engineering and project management
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    • 2009.05a
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    • pp.1479-1484
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    • 2009
  • It is commonly recognized to need performance management for successful construction project. PPC measurement of Last Planner System is one of construction project measurement method. PPC measurement is quantitatively assessment to go through construction, and that is not completely to be trusted when compare a project with another or an individual case work with another in same project. According to, purpose of this study is comparison indicator establishment that compare project with another or an individual case work with another it is not use PPC measurement for quantitatively assessment to go through construction. The procedure of this study is derive of the point at issue of existing PPC measurement for a aim PPC measurement in this study expenditure and select weight about that and it is applied to actually construction.

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Design of Simple Direct Comparison Measurement System from 10 MHz to 1 GHz for Thermistor Mounts Calibration (서미스터 마운트 교정을 위한 10 MHz에서 1 GHz 주파수 대역의 단순 직접 비교 측정시스템 설계)

  • Cha, Yun-Bae;Jang, Young-Guen;Kim, Boo-Il
    • The Journal of the Korea institute of electronic communication sciences
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    • v.15 no.3
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    • pp.405-412
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    • 2020
  • The thermistor mount is used for precise RF power measurement because the calibration factor is constant according to the change of power. The calibration factor of the standard mount can be measured with an uncertainty less than 0.5 % from the 10 MHz to 1 GHz by direct comparison with the transfer standard using the DC substitution method. Recently, as the supply of precision power meter based on DC substitution method allows simple and fast measurement, a simple direct comparison measurement system with the same level uncertainty was designed and the minimum required specifications of components through analysis of mismatch error was proposed. The uncertainty was evaluated for system validation, and the results show that uncertainties have been well maintained within 0.5 % in the measurement frequencies.