• Title/Summary/Keyword: measurement systems

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Development of Robust Embedded Measurement System by Using PXI Bus (PXI 버스를 이용한 강인한 범용계측시스템 개발)

  • 유제택
    • Journal of Institute of Control, Robotics and Systems
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    • v.10 no.2
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    • pp.171-177
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    • 2004
  • Many instrumentations have been used to acquire the performance data of military systems fer many years. But they could not satisfy environmental specifications(vibration, shock, temperature) and processing speed to apply for the performance test of military systems because of having developed as common vehicles/fixed installation equipments. Thus a new rugged embedded measurement system is required to process large data in high processing speed(Maximum sample rate:1.25Mhz/ch) with rugged environmental specifications. We have developed embedded measurement systems by using PXI(PCI extension for Instrumentation)bus interface composed of a stand alone controller and versatile data acquisition boards(analog, digital, vision, temperature and small signal conditioner) on PC-based environment to solve these problems. Operation programs have been developed using Lab_View and the performances have been validated experimentally.

Measurement Feedback Control of a Class of Nonlinear Systems via Matrix Inequality Approach (행렬 부등식 접근법을 이용한 비선형 시스템의 측정 피드백 제어)

  • Koo, Min-Sung;Choi, Ho-Lim
    • Journal of Institute of Control, Robotics and Systems
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    • v.20 no.6
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    • pp.631-634
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    • 2014
  • We propose a measurement state feedback controller for a class of nonlinear systems that have uncertain nonlinearity and sensor noise. The new design method based on the matrix inequality approach solves the measurement feedback control problem of a class of nonlinear systems. As a result, the proposed methods using a matrix inequality approach has the flexibility to apply the controller. In addition, the sensor noise can be attenuated for more generalized systems containing uncertain nonlinearities.

Bootstrap Confidence Intervals of Precision-to-Tolerance Ratio (PTR의 붓스트랩 신뢰구간)

  • Chang, Mu-Seong;Kim, Sang-Boo
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.30 no.2
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    • pp.37-43
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    • 2007
  • ANOVA is widely used for measurement system analysis. It assumes that the measurement error is normally distributed, which may not be seen in certain industrial cases. In this study, the exact and bootstrap confidence intervals for precision-to-tolerance ratio (PTR) are obtained for the cases where the measurement errors are normally and non-normally distributed and the reproducibility variation can be ignored. Lognormal and gamma distributions are considered for non-normal measurement errors. It is assumed that the quality characteristics have the same distributions of the measurement errors. Three different bootstrap methods of SB (Standard Bootstrap), PB (Percentile Bootstrap), and BCPB (Biased-Corrected Percentile Bootstrap) are used to obtain bootstrap confidence intervals for PTR. Based on a coverage proportion of PTR, a comparative study of exact and bootstrap methods is performed. Simulation results show that, for non-normal measurement error cases, the bootstrap methods of SB and BCPB are superior to the exact one.

Accuracy Evaluation and Accreditation Procedure of Measurement Systems (측정시스템의 정확도 평가와 공인화 절차)

  • Choi, Ju-Ho;Hong, Seong-Su;Yoo, Jun
    • Journal of the Korea Institute of Military Science and Technology
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    • v.2 no.2
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    • pp.261-270
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    • 1999
  • This paper presents how to evaluate the accuracy and uncertainty of the measuring techniques and the measurement systems, and establish their accreditation procedures. There are largely static error and dynamic error in the measurement error. In particular, the static error which always remains in the measurement systems is obtained by proposed error equations. In addition, the accreditation procedures are proposed.

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An Image-Based Remote Snow Height Measurement System using a USN (이미지 및 USN 기반 원격 적설량 측정 시스템)

  • Lee, Hyung-Bong;Moon, Jung-Ho;Chung, Tae-Yun
    • IEMEK Journal of Embedded Systems and Applications
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    • v.6 no.2
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    • pp.76-85
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    • 2011
  • In conventional methods for measuring snow height, a graduated pole is installed on ground in an area of interest and the snow height is manually read from the pole. Recently, automated snow height measurement systems have been introduced to improve the conventional methods. The automated measurement systems, however, are quite expensive since they use the reflection of ultrasonic waves or laser beams. In addition, it is not easy to move the location of the automated measure systems. This paper proposes a snow height measurement system equipped with image sensors and wireless communication capability via a USN and the Internet. The proposed system has a resolution of 5 cm and easy to deploy without difficulties, which can be usefully used to monitor unforseen local snowfalls.

A Study on QoS Measurement for Electronic Commerce Systems (전자상거래 시스템의 서비스 품질 측정에 관한 연구)

  • Kim Jeong-Su;Seo Sang-Koo
    • Journal of Information Technology Applications and Management
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    • v.12 no.3
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    • pp.129-150
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    • 2005
  • Due to the advance of the Internet, the electronic commerce is getting more widely used, and customer's demand for the e-Commerce service quality is rapidly increasing. On the other hand, e-Commerce companies required the Internet services whose quality is provided more reliable service to their customers. Therefore, it is very important to provide both e-Commerce companies and customers with the measurement and service quality in real-life network environment. But the research on the service quality measurement method for electronic commerce systems has been limited because ISP and e-Commerce providers seldom disclose detailed service measures such as, where and how much service delay incurred. In this paper, we construct sample e-Commerce systems and try to measure the service quality of the systems in real network environment. We have analyzed the delay zones and causes using a measurement tool. We must reflect the improvement method against delay causes. Accordingly, the customers can be experiences the better service quality. We hope that this research will be the groundwork for future research on the service quality of various types of e-Commerce systems and online services.

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A Study on Development of Integration Performance Measurement Model for Each Stage of Information Systems Integration and Measurement Indicators of Physical Integration Stage (정보시스템 통합단계별 성과측정 모형 및 물리적 통합단계의 측정지표 개발에 관한 연구)

  • Jung, Hae-Yong;Ra, Jong-Hei
    • Journal of Information Technology Services
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    • v.7 no.4
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    • pp.247-268
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    • 2008
  • This study aims to develop an integration performance measurement model for each stage of information systems integration. In order to achieve the purpose of the research, first of all, the concepts of IS integration or consolidation are analyzed through theoretical and practical reviews. Also, a number of important studies of domestic and overseas cases about the stage models of IS integration or consolidation are critically reviewed. Second, we proposed three step stage model of is integration, Physical Integration stage, Application Integration stage, Service Integration stage, and Also proposed the performance measurement model for each stage of information systems integration. Third, especially in case of performance indicators and performance measurement methodology for physical integration stage are illustratively proposed, based upon the case of NCIA (National Computing Integration Agency) in Korea. This study provides the theoretical basis for reasonably deriving the stage model and performance measurement model for each stage of Information Systems Integration, and they are validating through investigating domestic and foreign practices. The results of this study are very likely to contribute to presenting the practical guideline for desirably implementing is integration or IS consolidation.

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.

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.

Estimations of Measurement System Variability and PTR under Non-normal Measurement Error (비정규 측정오차의 경우 측정시스템 변동과 PTR 추정)

  • Chang, Mu-Seong;Kim, Sang-Boo
    • Journal of Korean Society for Quality Management
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    • v.35 no.1
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    • pp.10-19
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    • 2007
  • ANOVA is widely, used for measurement system analysis. It assumes that the measurement error is normally distributed, which nay not be seen in some industrial cases. In this study the estimates of the measurement system variability and PTR (precision-to-tolerance ratio) are obtained by using weighted standard deviation for the case where the measurement error is non-normally distributed. The Standard Bootstrap method is used foy estimating confidence intervals of measurement system variability and PTR. The point and confidence interval estimates for the cases with normally distributed measurement error are compared to those with non-normally distributed measurement errors through computer simulation.