• Title/Summary/Keyword: Measurement Deviation

Search Result 960, Processing Time 0.023 seconds

A Study on the Reasonable Measurement Point of Root Collar Diameter of Landscape Trees in Korea (한국 조경수목 근원직경 측정의 합리적 위치 설정에 대한 연구)

  • Han, Yong-Hee;Kim, Hwa-Jeong;Kim, Do-Gyun
    • Journal of the Korean Institute of Landscape Architecture
    • /
    • v.49 no.5
    • /
    • pp.59-70
    • /
    • 2021
  • This study was to investigate the measurement point of root collar diameter of landscape trees in Korea. It may contribute to avoiding disputes caused by the difference in measurement criteria of root collar diameter of landscape trees between tree growers and constructors. The difference between landscape trees' root collar diameter measurement point was 3.59cm from 6cm underground to the surface and 1.35cm from 0cm to 6cm above ground. The source root collar diameter measurement point difference was larger in the basement than in the ground. The standard deviation of the root collar diameter of the landscape tree was 0.64 from 6cm underground to the surface, and the difference in standard deviation from 0cm to 6cm above ground was 0.16. The difference by measurement point of the root collar diameter was larger in the basement than in the ground. It has been proposed to set the reasonable measurement point of the landscaping tree root collar diameter at the inflection point where the standard deviation of the tree trunk diameter is the smallest in line with the size change of the standard for each root collar diameter measurement point. By tree species, Cornus officinalis Siebold & Zucc. 18cm above the ground, Chionanthus retusus Lindl. & Paxton. 12cm above the ground, Zelkova serrata (Thunb.) Makino. 12cm above the ground, Celtis sinensis Pers. 12cm above the ground, Styrax japonicus Siebold & Zucc. 10 cm above the ground, Cornus officinalis Siebold & Zucc. 10cm above the ground, Acer palmatum Thunb. ex Murray. 6cm above the ground, Ilex rotunda Thunb. 6cm above the ground, Quercus myrsmaefolia Blume. 4cm above the ground, Lagerstroemia indica L. 2cm above the ground The above heights were shown as reasonable measurement points. The difference by landscape tree root collar diameter measurement site showed that the standard deviation was small throughout the tree species, and the reasonable average measurement point with a stable slope of the deviation was 12cm or more on average. It can be said that the reasonable measurement point of the root collar diameter of a landscape tree is set at an average of 12cm above the ground. However, recognizing 30cm, which is a familiar ruler(尺) in traditional practices, is quick, It was recommended to measure at the height of 30cm from the surface for a reasonable measurement point of the root collar diameter of a landscape tree, for the uniformity of measurement standards.

Development of Wall-Thinning Evaluation Procedure for Nuclear Power Plant Piping-Part 1: Quantification of Thickness Measurement Deviation

  • Yun, Hun;Moon, Seung-Jae;Oh, Young-Jin
    • Nuclear Engineering and Technology
    • /
    • v.48 no.3
    • /
    • pp.820-830
    • /
    • 2016
  • Pipe wall thinning by flow-accelerated corrosion and various types of erosion is a significant and costly damage phenomenon in secondary piping systems of nuclear power plants (NPPs). Most NPPs have management programs to ensure pipe integrity due to wall thinning that includes periodic measurements for pipe wall thicknesses using nondestructive evaluation techniques. Numerous measurements using ultrasonic tests (UTs; one of the nondestructive evaluation technologies) have been performed during scheduled outages in NPPs. Using the thickness measurement data, wall thinning rates of each component are determined conservatively according to several evaluation methods developed by the United States Electric Power Research Institute. However, little is known about the conservativeness or reliability of the evaluation methods because of a lack of understanding of the measurement error. In this study, quantitative models for UT thickness measurement deviations of nuclear pipes and fittings were developed as the first step for establishing an optimized thinning evaluation procedure considering measurement error. In order to understand the characteristics of UT thickness measurement errors of nuclear pipes and fittings, round robin test results, which were obtained by previous researchers under laboratory conditions, were analyzed. Then, based on a large dataset of actual plant data from four NPPs, a quantitative model for UT thickness measurement deviation is proposed for plant conditions.

Location Measurement method Depending on Reflection Characteristics of Ultrasonic Sensors for The Flat LED Lamp (평면 LED 램프에서의 초음파 센서의 반사특성을 고려한 위치측정 기법)

  • Heo, Young-Rok;Yun, Jang-Hee;Ryeom, Jeong-Duk
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
    • /
    • v.27 no.12
    • /
    • pp.38-43
    • /
    • 2013
  • In this paper, the location measurement method for the reliable location data using ultrasonic sensors is proposed for the dimming control of the LED flat lamp. The measurement errors depending on the reflection angle of the object have to be considered to obtain the reliable location data in the ultrasonic sensors. In the experiment, the cause of the measurement errors depending on reflection angle is analyzed and velocity change of ultrasonic wave depending on reflection angle is measured. And the location measurement method depending on velocity change of ultrasonic wave is proposed. From the results, the average absolute deviation of the x-coordinates was 1.47cm when the location measurement method was considered, and it was closer to the true values than the average absolute deviation of the x-coordinates which was 5.89cm without regard to the reflection angle.

Development of a 3D Roughness Measurement System of Rock Joint Using Laser Type Displacement Meter (레이저 변위계를 이용한 암석 절리면의 3차원 거칠기 측정기 개발)

  • 배기윤;이정인
    • Tunnel and Underground Space
    • /
    • v.12 no.4
    • /
    • pp.268-276
    • /
    • 2002
  • In this study, a 3D coordinate measurement system equipped with a laser displacement meter for digitizing rock joint surface was established and the digitized data were used to calculate several roughness parameters. The parameters used in this study were micro avenge inclination $angle(i_{ave})$, average slope of joint $asperity(SL_{ ave})$, root mean square of $i-angle(i_{rms})$, standard deviation of height(SDH), standard deviation of $i-angle(SD_i)$, roughness profile $index(R_P)$, and fractal dimension(D). The relationships between the roughness parameters based on the digitzation of the surface profile were analyzed. Since the measured value varied according to the degree of reflection and the variation of colors at the measuring point, rock joint surface was painted in white to minimize the influence of the surface conditions. The comparison of the measured values and roughness parameters before and after painting revealed the better consequence from measurement on the painted surfaces. Also, effect of measuring interval was studied. As measured interval was increased, roughness parameters were exponentially decreased. The incremental sequence of degree of decrease was $SDH\; i_{ave},\; i_{rms},\; SD_i,\;and\; R_ p-1$. As a result of comparison of parameters from pin-type measurement system and laser type measurement system, all value of parameters were higher when laser-type measurement system was used, except SDH.

Verification of Reliable Blood Pressure Monitor in a Moving Ambulance during an Emergency (응급상황시 이송중인 구급차에서 신뢰할 수 있는 혈압계 검증)

  • Jeon, Jai-In
    • The Journal of the Convergence on Culture Technology
    • /
    • v.8 no.3
    • /
    • pp.91-97
    • /
    • 2022
  • The purpose of this study was to analyze the measurements of blood pressure and time using manual and automatic blood pressure monitors in various road conditions to verify reliable blood pressure monitor in a moving ambulance. First, the manual blood pressure monitor palpation on unpaved roads showed a systolic pressure deviation of 5 mmHg. However, the automatic blood pressure monitor showed two measurement failures, one reading failure, and the measured systolic pressure deviation was 35 mmHg. The measurement time was 102 seconds faster on average than the automatic blood pressure monitor. Second, the palpation of the manual blood pressure monitor while going over speed bumps remained constant at 130 mmHg. However, the automatic blood pressure monitor had a systolic pressure deviation of 52 mmHg. The measurement time was 61 seconds faster on average than the automatic blood pressure monitor. Finally, the manual blood pressure monitor palpation on the sharp curve road showed a systolic pressure deviation of 5 mmHg. The automatic blood pressure monitor had one reading failure and the measured systolic pressure deviation was 21 mmHg. The measurement time showed that the manual blood pressure monitor was 101 seconds faster than the automatic blood pressure monitor. As a result, in a moving ambulance during an emergency, the manual blood pressure monitor showed high reliability because the blood pressure measurement was constant and the measurement time was short.

Systematic Review of the Diagnosis of Pelvic Deviation for Chuna Manual Therapy (추나치료에 적용된 골반변위 진단법에 대한 체계적 문헌고찰)

  • Lee, Jun-Seok;Park, Kyeong-Won;Kim, Hyun-Tae;Park, Sun-Young;Shin, Byung-Cheul
    • Journal of Korean Medicine Rehabilitation
    • /
    • v.32 no.2
    • /
    • pp.83-94
    • /
    • 2022
  • Objectives This systematic review aimed to analyze research about pelvic deviation diagnosis for Chuna manual therapy (CMT) and to review the diagnosis methods, indices, and results of diagnosis. Methods Ten electronic databases were systematically searched up to January 4th 2022. Clinical studies and reviews containing pelvic deviation diagnosis for CMT or using CMT as a treatment of pelvic deviation were selected and evaluated. CMT diagnosis in clinical studies and reviews were isolated and analyzed by 2 independent reviewers. Results Thirteen clinical studies and three reviews were included in the evaluation. X-ray analysis and manual testing were the two main methods used in CMT diagnosis of pelvic deviation. For manual testing in clinical studies, leg length insufficiency testing was the most frequently used measurement index and the most common diagnostic results were anterior and posterior rotation. In the X-ray analysis, Obturator foramen and femur head line were the most frequently used measurement index and the most common diagnostic results were anterior rotation and posterior rotation. Conclusions The systematic review found that manual testing and X-ray analysis were mainly used for the diagnosis of pelvic deviation in CMT among clincial and review articles. As there was little research about diagnosing pelvic deviation in CMT and any existing research presented only low standards of evidence, further research should be updated with using a more standardized approach.

A study on the Finishing Characteristics of Ultra-precision System (초정밀 가공시스템의 염마 가공 특성에 관한 연구)

  • Bae, Myung-Il;Kim, Hong-Bae
    • Journal of the Korean Society for Precision Engineering
    • /
    • v.16 no.10
    • /
    • pp.11-16
    • /
    • 1999
  • In this study, Ultra-precision finishing system using micro abrasive film experimented using experimental variable film feed speed and grinding speed and structural steel(SM45C) with respect to 12~3{\mu}m$ micro abrasive film. the result are follows; (1) Experimental condition must setup dissimilar about each micro abrasive film. (2) To measurement deviation the smallest machined condition are 20mm/min in 12{\mu}m$, 5mm/min and 15mm/min in 9{\mu}m$ and 5{\mu}m$, 5mm/min in 3{\mu}m$ in film feed speed. (3) To measurement deviation the smallest machined condition are 180m/min in 12{\mu}m$, 84m/min in 9{\mu}m$, 56 and 84m/min in 5{\mu}m$, 104m/min in 3{\mu}m$ in grinding speed.

  • PDF

Study on Economical M&V Methoodology for the Lighting Control System (조명제어시스템 경제적인 실적확인 기법 연구)

  • Choi, Kyung-Shik;Han, Seung-Ho
    • Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
    • /
    • 2009.10a
    • /
    • pp.163-167
    • /
    • 2009
  • Although the domestic electric power consumption of lighting have shared 20${\sim}$30 % of the national electric power consumption, the spread of lighting control system which can reduce the electric power consumption have been insignificant. The government have set the demonstration project and given the incentive to promote the spread of lighting control system since 2008. The M&V (Measurement and Verification) methodology for lighting control system have not been set yet in our country, but the direct measurement was suggested in US. The direct measurement methodology can increase the accuracy of measurement, but it cost much money to burden a customer. This study have suggested a new M&V methodology which cost low and is simple relatively. I had measured the amount of electric consumption through both the direct measurement and the new M&V program computation, and have analyzed the deviation. The amount of electric consumption measured by the new M&V program computation have agreed with one by the direct measurement within the error range of the instrumentation in case of lab scale test, and the 4${\sim}$8 % deviation have existed in case of field evaluation.

  • PDF

Cantilever deflection measurement system for AFM with PSD (PSD를 이요한 AFM용 미세 탐촉자의 변위측정장치)

  • 김홍준;장경영
    • Proceedings of the Korean Society of Precision Engineering Conference
    • /
    • 2000.11a
    • /
    • pp.31-35
    • /
    • 2000
  • A cantilever deflection measurement system for AFM(atomic force microscope) was constructed by the laser deflection method using LEP type PSD. Design process including sensitivity analysis was presented and the performance of the system was demonstrated by several experiments using a sample specimen with 50nm-step on the surface. The measured displacement-amplification-factor showed good agreement with the expected one with about 8% deviation. The step height measurement data were compared to what were acquired by commercial AFM, and the result showed that there were about 5nm-deviation between the two data. These results satisfies our expectation in the stage of system design.

  • PDF

A Study on Roughness Measurement of Polished Surfaces Using Reflected Laser Beam Image (레이저빔 반사 화상을 이용한 연마면 거칠기 측정법에 관한 연구)

  • Shen, Yun-Feng;Lim, Han-Seok;Kim, Hwa-Young;Ahn , Jung-Hwan
    • Journal of the Korean Society for Precision Engineering
    • /
    • v.16 no.2 s.95
    • /
    • pp.145-152
    • /
    • 1999
  • This paper presents the principle and experimental results of a non-contact surface roughness measurement by means of screen projected pattern of lase beam reflected from a polished surface. In the reflected laser beam pattern especially from a fine surface like ground or polished one, light intensity varies from the center fo the image to its boundary as the Gaussian distribution. The standard deviation of a light intensity distribution is assumed to be a good non-contact estimator for measuring the surface roughnes, because the light reflectivity is known to be well related with the surface roughness. This method doesn't need to discriminate between the specularly reflected light and the diffusely reflected one, whereas the scattered laser intensity method must do. Nor it needs to adjust the change of light intensity caused by environmental lights or specimen materials. Reflected laser beam pattern narrowly spreads out in the vertical direction to tiny scratches on the polished surface due to abrasives. The deeper the scratch the more the dispersion, which means the rougher surface. The standard deviation of the pattern is nearly in proportion to the surface roughness. Measurement errors by this method are shown to be below 10 percent compared with those obtained by a common contact method. The inclination of measuring unit from the normal axis causes the measurement errors up to 10 percent for an angle of 4 degree. Therefore the proposed method can be used as an on-the-machine quick roughness estimator within 10 percent measurement error.

  • PDF