• Title/Summary/Keyword: Measurement

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A Statistical Program for Measurement Process Capability Analysis based on KS Q ISO 22514-7 Using R (R을 이용한 KS Q ISO 22514-7 측정 프로세스 능력 분석용 프로그램)

  • Lee, Seung-Hoon;Lim, Keun
    • Journal of Korean Society for Quality Management
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    • v.47 no.4
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    • pp.713-723
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    • 2019
  • Purpose: The purpose of this study is to develop a statistical program for capability analysis of measuring system and measurement process based upon KS Q ISO 22514-7. Methods: R is a powerful open source functional programming language that provides high level graphics and interfaces to other languages. Therefore, in this study, we will develop the statistical program using R language. Results: The R program developed in this study consists of the following five modules. ① Measuring system capability analysis with Type 1 study data: MSCA_Type1.R ② Measuring system capability analysis with Linearity study(Type 4 study) data: MSCA_Type4.R ③ Measurement process capability analysis with Type 1 study & Gage R&R study data: MPCA_T1GRR.R ④ Measurement process capability analysis with Type 4 study & Gage R&R study data: MPCA_T4GRR.R ⑤ Attribute measurement processes capability analysis : AttributeMP.R Conclusion: KS Q ISO 22514-7 evaluates measuring systems and measurement processes on the basis of the measurement uncertainty that was determined according to the GUM(KS Q ISO/IEC Guide 98-3). KS Q ISO 22514-7 offers precise procedures, however, computations are more intensive. The R program of this study will help to evaluate the measurement process.

Measurement of Elastic Constants by Simultaneously Sensing Longitudinal and Shear Waves as an Overlapped Signal

  • Seo, Hogeon;Song, Dong-Gi;Jhang, Kyung-Young
    • Journal of the Korean Society for Nondestructive Testing
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    • v.36 no.2
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    • pp.138-148
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    • 2016
  • Measurement of elastic constants is crucial for engineering aspects of predicting the behavior of materials under load as well as structural health monitoring of material degradation. Ultrasonic velocity measurement for material properties has been broadly used as a nondestructive evaluation method for material characterization. In particular, pulse-echo method has been extensively utilized as it is not only simple but also effective when only one side of the inspected objects is accessible. However, the conventional technique in this approach measures longitudinal and shear waves individually to obtain their velocities. This produces a set of two data for each measurement. This paper proposes a simultaneous sensing system of longitudinal waves and shear waves for elastic constant measurement. The proposed system senses both these waves simultaneously as a single overlapped signal, which is then analyzed to calculate both the ultrasonic velocities for obtaining elastic constants. Therefore, this system requires just half the number of data to obtain elastic constants compared to the conventional individual measurement. The results of the proposed simultaneous measurement had smaller standard deviations than those in the individual measurement. These results validate that the proposed approach improves the efficiency and reliability of ultrasonic elastic constant measurement by reducing the complexity of the measurement system, its operating procedures, and the number of data.

Study on the Promoting the Improvement of Work Environment by the Monitoring Committee for Work Environment Measurement (모니터링위원회를 통한 작업환경 개선 활성화 방안)

  • Hwang, Gyuseok
    • Journal of Korean Society of Occupational and Environmental Hygiene
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    • v.28 no.2
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    • pp.158-165
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    • 2018
  • Objectives: We analyzed the problems that work environment measurement results don't lead to workplace improvement in the Work Environment Measurement System to propose an alternative. Methods: We reviewed reports and articles written by the Korea Occupational Safety and Health Agency and academic circles to identify the problems in the current Work Environment Measurement System and suggest an alternative. Results: One of the reasons that the Work Environment Measurement has not resulted in workplace improvement is that there were no proper regulating systems for managing the workplace improvement plans or improvement results. Moreover, there are not enough professional manpower in ministry of labor to evaluate the improvement plans and results from the Work Environment Measurement. Therefore, all of the workplace whose Work Environment Measurement results exceed the occupational exposure limit (OEL) should be managed by regional ministry of labor, and outside experts and new system for verifying improvement are needed. Conclusions: To accomplish the purpose of Work Environment Measurement, it is necessary to improve the work environment according to the results of Work Environment Measure. For this, it is necessary for the government to manage the fulfillment of workplace improvement plans and for measurement agencies to secure expertise.

Analysis of Distance Measurement Accuracy in Aerial and Satellite Image Photogrammetry (항공사진측량과 위성영상측량에서 거리측정 정확도 연구)

  • Kim, Hyung-Moo;Tcha, Dek-Kie;Nam, Guon-Mo;Yang, Chul-Soo
    • Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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    • 2010.04a
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    • pp.253-255
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    • 2010
  • Needs to study on distance measurement accuracy in aerial and satellite photogrammetry are rapidly increased. However, conventional studies show some confused definitions between measurement accuracy and measurement precision as well as standard deviation(STDEV) and root mean square error(RMSE or RMSD). So, Finite definitions of measurement accuracy and measurement precision as well as STDEV and RMSD are addressed in this paper. Experiment result show using correct definitions improve the distance measurement accuracy in aerial and satellite photogrammetry rapidly, but not the distance measurement accuracy in aerial and satellite photogrammetry.

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Credit Risk Measurement Practices in Indian Commercial Banks - An Empirical Investigation

  • Arora, Swaranjeet
    • Asia-Pacific Journal of Business
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    • v.5 no.2
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    • pp.37-50
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    • 2014
  • Banking institutions have been facing variety of difficulties but the major cause of serious banking problems relates to lax credit standards for borrowers and counterparties, poor portfolio risk management, or a lack of attention to changes in economic or other circumstances that can lead to deterioration in the credit standing of a bank's counterparties. Although credit risk is an important factor that financial institutions should cope with, but the determinants of measuring credit risk have been studied less. This paper attempts to explore the determinants of credit risk measurement and to identify the factors that contribute to credit risk measurement practices in Indian banks and to compare credit risk measurement practices followed by Indian public and private sector banks, the empirical study has been conducted and views of employees of various banks have been tested using statistical tools. This study explored the phenomenon from different perspectives and revealed that single-name credit risk measurement and portfolio credit risk measurement are the key components that contribute to credit risk measurement in Indian banks. From the descriptive and analytical results, it can be concluded that Indian banks efficiently measure credit risk. The results also indicate that there is a significant difference between the Indian public and private sector banks in single-name credit risk measurement while, these banks do not significantly differ in portfolio credit risk measurement aspect.

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The Volume Measurement of Air Flowing through a Cross-section with PLC Using Trapezoidal Rule Method

  • Calik, Huseyin
    • Journal of Electrical Engineering and Technology
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    • v.8 no.4
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    • pp.872-878
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    • 2013
  • In industrial control systems, flow measurement is a very important issue. It is frequently needed to calculate how much total fluid or gas flows through a cross-section. Flow volume measurement tools use simple sampling or rectangle methods. Actually, flow volume measurement process is an integration process. For this reason, measurement systems using instantaneous sampling technique cause considerably high errors. In order to make more accurate flow measurement, numerical integration methods should be used. Literally, for numerical integration method, Rectangular, Trapezoidal, Simpson, Romberg and Gaussian Quadrature methods are suggested. Among these methods, trapezoidal rule method is quite easy to calculate and is notably more accurate and contains no restrictive conditions. Therefore, it is especially convenient for the portable flow volume measurement systems. In this study, the volume measurement of air which is flowing through a cross-section is achieved by using PLC ladder diagram. The measurements are done using two different approaches. Trapezoidal rule method is proposed to measure the flow sensor signal to minimize measurement errors due to the classical sampling method as a different approach. It is concluded that the trapezoidal rule method is more effective than the classical sampling.

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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Evaluation Method for Measurement System and Process Capability Using Gage R&R and Performance Indices (게이지 R&R과 성능지수를 이용한 측정시스템과 공정능력 평가 방법)

  • Ju, Youngdon;Lee, Dongju
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.42 no.2
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    • pp.78-85
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    • 2019
  • High variance observed in the measurement system can cause high process variation that can affect process capability badly. Therefore, measurement system analysis is closely related to process capability analysis. Generally, the evaluation for measurement system and process variance is performed separately in the industry. That is, the measurement system analysis is implemented before process monitoring, process capability and process performance analysis even though these analyses are closely related. This paper presents the effective concurrent evaluation procedure for measurement system analysis and process capability analysis using the table that contains Process Performance (Pp), Gage Repeatability & Reproducibility (%R&R) and Number of Distinct Categories (NDC). Furthermore, the long-term process capability index (Pp), which takes into account both gage variance and process variance, is used instead of the short-term process capability (Cp) considering only process variance. The long-term capability index can reflect well the relationship between the measurement system and process capability. The quality measurement and improvement guidelines by region scale are also described in detail. In conclusion, this research proposes the procedure that can execute the measurement system analysis and process capability analysis at the same time. The proposed procedure can contribute to reduction of the measurement staff's effort and to improvement of accurate evaluation.

A Study on Quality Improvement by Evaluation and Application of GUM-based Measurement Uncertainty (GUM 기반 측정불확도의 평가 및 적용에 의한 품질개선)

  • Insoo Choi;Sun Hur
    • Journal of Korean Society for Quality Management
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    • v.51 no.3
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    • pp.419-434
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    • 2023
  • Purpose: Measurement results obtained under non-ideal measurement environment conditions may contain uncertain factors. As a result, the reliability of measurement results may be deteriorated. In this study, we tried to find ways to improve quality by evaluating and applying measurement uncertainty based on GUM. Methods: In the flatness measurement of semiconductor parts, uncertainty factors that could occur under actual environmental conditions of workers were derived, and measurement uncertainties were calculated, and methods for minimizing the main factors affecting the measurement results were analyzed. Results: Depending on the part and the coordinate measuring machine, it was shown that the effect of dispersion caused by repeated measurements as type A uncertainty and the effect of the calibration results of equipment as type B uncertainty have the main influence. Conclusion: Depending on the uncertainty factors of type A and type B and the influence of the total expanded uncertainty, the central value and confidence interval of the initial measurement results showed fluctuations. It is considered that analysis and measures for the main uncertainty factors are needed as quality improvement in the industrial field.

Planar near-field antenna measurement method based on symplectic relation and reaction concept

  • Cho, Yong-Heui
    • International Journal of Contents
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    • v.6 no.2
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    • pp.6-9
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    • 2010
  • Using symplectic relation and reaction concept, we propose a planar near-field antenna measurement method. A generalized probe compensation equation is deduced to obtain the probe correction formulation. To verify our approach, a reflector antenna with $1{\times}2$ horn array is fabricated and measured in the near-field measurement facility. The near-field measurement results are compared with the physical optics (PO) simulation. The results of measurement and simulation agree very well near to the mainbeam.