• Title/Summary/Keyword: Improve measurement accuracy

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Application of Image Processing Technique to Improve Production Efficiency of Fine Pitch Hole Based on Laser (레이저 미세피치 홀 가공의 생산효율성 향상을 위한 영상처리 측정 기법 적용)

  • Pyo, C.R.
    • Transactions of Materials Processing
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    • v.19 no.5
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    • pp.320-324
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    • 2010
  • Multi-Layer Ceramic Circuit(MLCC) in the face of thousands of fine pitch multi hole is processed. However, the fine pitch multi hole has a size of only a few micrometers. Therefore, in order to curtail the measurement time and reduce error, the image processing measurement method is required. So, we proposed an image processing measurement algorithm which is required to accurately measure the fine pitch multi hole. The proposed algorithm gets image of the fine pitch multi hole, extracts object from the image by morphological process, and extracts the parameters of its position and feature by edge detecting process. In addition, we have used the sub-pixel algorithm to improve accuracy. As a result, the proposed algorithm shows 97% test-retest measurement reliability within 2 ${\mu}m$. We found that the algorithm was wellsuited for measuring the fine pitch multi hole.

Experimental verification and improvement of heat transfer tube local wall temperature measurement method

  • Jiabao Liu;Xiaxin Cao;Peixun Yang
    • Nuclear Engineering and Technology
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    • v.55 no.12
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    • pp.4317-4328
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    • 2023
  • To ensure the measuring accuracy of the wall temperature, the outer wall temperature measurement values by using three kinds of thermocouple welding methods were analyzed and evaluated in the paper, including single-point flush-mounted in the wall groove method, single-point insert-mounted in the wall groove, and outer surface direct welding method, based on the application of a tube-in-tube condensing heat exchanger. And the impacts of silver, tin, and thermal resistance adhesive as filling materials on wall temperature measurement were also investigated, and the results were compared to that obtained without filling materials. The results showed that the wall temperatures measured by the three welding methods were lower than the theoretically calculated value. And the wall temperature measured by the outer surface direct welding method was lowest under the same experimental conditions. The wall temperatures measured by single-point flush-mounted and insert-mounted in the wall groove methods were also affected by different welding filling materials. It was found that the greater the thermal resistance of filling materials, the smaller the heat loss. By analyzing the reasons for the low measured value of wall temperature, a new wall temperature measurement method was developed to improve the accuracy of the current measurement method. Meanwhile, the outer wall temperature measurement experiments of vertical and horizontal heat transfer tubes were carried out to validate and calibrate the improved outer wall temperature measurement method. The results showed that the average outer wall temperature deviation measured by the improved wall temperature measurement method ranged from - 0.82% to +2.29% for vertical tubes and - 4.75% to - 1.44% for horizontal tubes, and the improved measurement method had good measurement accuracy.

Nursing Students' Hearing Levels and Blood Pressure Measurement Accuracy (간호대학생의 청력수준과 혈압측정의 정확도)

  • Kim, Heeyoung;Chung, Young Hae;Kim, Yun Hee
    • Journal of Korean Academy of Fundamentals of Nursing
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    • v.23 no.3
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    • pp.275-282
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    • 2016
  • Purpose: This study was done to examine the relationship between nursing students' hearing levels and accuracy of blood pressure (BP) measurements. Methods: Participants were 107 students who had finished their fundamental nursing practice and clinical practicum and who used earphones. Data were collected from October 13 to November 30, 2014 and from April 30 to May 19, 2015. Students' hearing thresholds were examined using an audiometer. Students were assigned to take two BP measurements on BP measurement training simulators, but only the second measurement was used for analysis. Results: All nursing students' hearing levels were within normal range, and there was no significant difference found among the settings for diastolic blood pressure. However, there were significant differences between low systolic blood pressure (SBP) (below 120mmHg) and high SBP (over 140mmHg) (z=9.02, p=.011). Measurement error in SBP showed a positive correlation with hearing threshold in the right ear at frequencies of 1000Hz and 500Hz. Conclusion: Findings indicate that BP measurement error is correlated with hearing threshold at some frequencies. To reduce measurement error, nursing students should be provided with health education about hearing and to improve training for students, further studies need to examine other factors influencing BP measurement error.

High-Accuracy Coastdown Test Method by Distance-Time Measurement: II. Development of a Short Distance Method and its Evaluation (거리·시간 측정에 의한 고정도 타행시험법: II. 단거리 방법의 개발 및 시험)

  • Hur, N.G.;Ahn, I.K.;Petrushov, V.A.
    • Transactions of the Korean Society of Automotive Engineers
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    • v.3 no.3
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    • pp.1-8
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    • 1995
  • In the companion paper of the present paper, a coast down test method to determine the resistance forces on running vehicle based on the distance-time measurement was explained along with the suggestions to improve its accuracy and testing methodology. In the present paper some of the suggestions discussed previously are implemented and actually road tested to see the applicability of the improved method(short distance method) in the field. From the results. it is shown that the short distance method which requires only 600m long proving ground road gives at least comparable results on the accuracy compared to the original S-t method which requires 2000m. It is hoped that the present method be further refiend to give more accurate results.

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Measurement of Interfacial Crack Length by Ultrasonic Scattering Compensation Depending on Thickness Variations of Bonded Dissimilar Components (이종 접합부재의 두께 변화에 따른 초음파 산란 보정에 의한 계면균열 길이의 측정)

  • Chung, Nam-Yong
    • Transactions of the Korean Society of Automotive Engineers
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    • v.14 no.2
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    • pp.67-75
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    • 2006
  • In this paper, the compensation of ultrasonic scattering on interface crack depending on thickness variations of A1/Epoxy bonded dissimilar components was applied to improve measuring accuracy by using ultrasonic attenuation coefficient. The optimum conditions of theoretical value and experimental measuring accuracy by the ultrasonic method in A1/Epoxy bonded dissimilar components have been investigated. From the experimental results, the measurement method of interfacial crack lengths by using ultrasonic attenuation coefficient was proposed and discussed. After the ultrasonic scattering compensation depending on thickness variations of bonded dissimilar components was carried out, the measuring accuracy of interfacial crack length was improved by 5%.

Improvement of Mass Flow and Thickness Accuracy in Hot Strip Finishing Mill

  • Lee, Man-Hyung;Yoon, Ji-Sup
    • 제어로봇시스템학회:학술대회논문집
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    • 2001.10a
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    • pp.73.3-73
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    • 2001
  • Finishing mill (FM) is set up with rolling conditions (rolling speed, rolling force, roll gap, etc.) calculated by a FSU (Finisher Setup) model considering the temperature, qualities and size of a transfer bar and a strip at the entry and exit of FM before the transfer bar is rolled through FM. If the accuracy of setup is low mass flow unbalance occurs, so that the accuracies of the strip thickness and width become lower or rolling operation fault occurs. Therefore, to enhance the performance of the FSU model and to improve mass flow and the thickness accuracy of a strip in the 7-stand finishing mill using a hot strip speed measurement system. This study is being performed. In this paper, the speed measurement system, a developed neural network for predicting ...

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A Study on the Error Detection of Attached Cadastral Maps using GIS (GIS를 이용한 연속지적도 오류검증 방안)

  • Jung, Gu-Ha;Jun, Chul-Min;Koh, Jun-Hwan;Park, Yu-Ri
    • Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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    • 2007.04a
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    • pp.243-248
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    • 2007
  • This study proposed a procedure to improve the error defection of attached cadastral maps using digital map data. In addition, this study also provided the direction for the accuracy improvement of attached cadastral maps by comparing analysis methods. - such as centroid, Lee Sallee shape index, and area index. The analysis is performed as follows. First, by using centroid measurement, the center point of cadastral maps and attached cadastral maps are compared. Secondly by using Lee Sallee shape measurement, the location accuracy of range area is investigated. Thirdly, by using area measurement, the range area within allowable error scope is verified. Based on analysis, the discrepancy between cadastral maps and the attacked cadastral maps are detected as follows; 98.2% from Lee Sallee shape index, 41.8% from centroid, 15.4% from area index in the whole error.

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A Study on Evaluation of an Automatic Tool Compensation System in CNC Machine Tool (CNC 공작기계에서의 자동공구 보정시스템의 평가에 관한 연구)

  • 정상화;신현성;김현욱
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • 2001.04a
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    • pp.371-375
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    • 2001
  • The tool wear that is developed by long-term machining in mold manufacturing with machining center makes a severe influence to the accuracy and the surface roughness. In this reason, tool-wear supervising system which has guaranteed high accuracy and high speed is needed to improve the measurement quality. Touching probe and touch sensor are widely used to measure the tool profile at on-machine measurement. In this paper, using the newly developed electric touch point measuring system, the Automatic Tool Compensation System is developed to correct the error of tool diameter resulted from the wear, and the operating method of this system is also provided.

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Development of an Automatic Tool Compensation System for M/C (머시닝센터용 자동공구보정시스템의 개발)

  • 정상화;신현성;김현욱
    • Transactions of the Korean Society of Machine Tool Engineers
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    • v.10 no.4
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    • pp.48-54
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    • 2001
  • The tool wear that is developed by long-term machining in mold manufacturing with machining center makes a severe influence to the accuracy and the surface roughness. in this reason, tool-wear supervising system which has guaranteed high accuracy and high speed is needed to improve the measurement quality. Touching probe and touch sensor are widely used to measure the tool profile at on-machine measurement. In this paper, using the newly developed electric touch point measuring system, the Automatic Tool Compensation System is developed to correct the error of tool diameter resulted from the wear, and the operating method of this system is also provided.

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Adaptive Nonlinearity Compensation in Laser Interferometer using Neural Network (신경망 회로를 이용한 레이저 간섭계의 적응형 오차보정)

  • Heo, Gun-Hang;Lee, Woo-Ram;You, Kwan-Ho
    • Proceedings of the KIEE Conference
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    • 2007.04a
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    • pp.86-88
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    • 2007
  • In the semiconductor manufacturing industry, the heterodyne laser interferometer plays as an ultra-precise measurement system. However, the heterodyne laser interferometer has some unwanted nonlinearity error which is caused from frequency-mixing. This is an obstacle to improve the measurement accuracy in nanometer scale. In this paper we propose a compensation algorithm based on RLS(recursive least square) method and artificial intelligence method, which reduce the nonlinearity error in the heterodyne laser interferometer. With the capacitance displacement sensor we get a reference signal which can be transformed into the intensity domain. Using the back-propagation Neural Network method, we train the network to track the reference signal. Through some experiments, we demonstrate the effectiveness of the proposed algorithm in measurement accuracy.

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