• International Journal of Quality Innovation
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• v.3 no.2
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• pp.46-56
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• 2002

The presence of imprecise measurement may seriously affect the efficiency of process control and production cost. A cost model is derived to determine the design parameters of the economic asymmetric $\bar{X}$ and S control charts including measurement errors. The effects of imprecise measurement on the performance of the economic asymmetric $\bar{X}$ and S control charts and production cost are examined for the case where the process mean and process standard deviation may change. Application of the proposed control charts is demonstrated through an example. Numerical examples illustrate the effects of imprecise measurement on the design parameters of the proposed control charts. It shows that the imprecision measurement may seriously affrct the ability of the proposed control charts to detect process disturbances quickly, change the sampling frequency, and increase the production cost compared to the control charts excluding measurement errors.

• Proceedings of the KIEE Conference
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• 2001.07d
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• pp.2561-2563
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• 2001

This research is about the remote control of the infra-ray signal producer and the received signal memory-type control unit. Also by using the infra-ray signal from the remote control, reduction of malfunctions due to infra-ray signal from other devices are presented. Applications on various electric and electronic items to improve the convenience are also shown.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.22 no.50
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• pp.55-63
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• 1999

Past studies on economic control charts for controlling process means assumed that the measures of a quality characteristic do not have measurement error. In practice, however, this assumption is frequently violated. In this paper, the economic design models of three control charts(Xbar control chart, Xbar control chart with warning limits, and CUSUM control chart) for controlling process means are developed on the assumption that the measures can have measurement error. The effects of measurement error on the process control cost and design parameters of three economic control charts are examined. According to the experiments done in this study, when measurement error exists, the economic CUSUM control chart has lower process control cost in comparison with two other control charts. When measurement error becomes larger, both the sample size and the sampling interval increase while the control limits decrease.

• 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.

• Transactions of the Korean Society of Automotive Engineers
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• v.14 no.1
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• pp.92-99
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• 2006

The swirl ratio of a charge in the cylinder was estimated by calculating the ratio of the rotary speed of charge which could be simulated from the rotary speed of paddle in the swirl measurement apparatus, to the engine speed which could be calculated by measuring intake air flow rate. The automation of the swirl ratio measurement for cylinder head was achieved by controling both valve lift in cylinder head and a suction pressure of surge tank using two step-motors. The number of measurement position for calculating mean swirl ratio was varied by adjusting the interval of valve lift. The mean swirl ratio with varying the number of measurement position showed nearly constant value. Two measurement methods for measuring the swirl ratio were compared, one was to control the suction pressure of the surge tank with PID (proportional, integral, differential) mode with by-pass valve controlled by the step motor and the other did not control the surge tank pressure by fixing the by-pass valve. The difference of the mean swirl ratio between the two measurement methods showed nearly constant value with varying the number of measurement position. This means that the w/o PID control method could be preferred to the PID control method which has been used, due to the simpleness of the swirl measurement.

• The Transactions of the Korean Institute of Power Electronics
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• v.5 no.6
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• pp.552-559
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• 2000

Most of the sensorless vector control methods use the equivalent circuit of induction motors. Therefore parameter auto-measurement of drive motor is essential function in commercial sensorless vector control inverters. The accuracy of motor parameter measurement greatly affects the performance of sensorless vector control. In this paper limitations of conventional measurement methods are examined, and new measurement methods are proposed to solve those limitations.

• Journal of Institute of Control, Robotics and Systems
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• v.20 no.11
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• pp.1136-1141
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• 2014

This paper proposes a new contact type ball tracking sensor to improve the control performance of a low cost ball-and-beam system. It is well-known that the impulsive measurement noise contained in ball position measurement is one of the factors which severely degrades the ball-and-beam control performance. The impulsive ball position measurement noises often appear under the sporadical ball floating on the beam. This fact motivates us to devise a simple analog preprocessing circuit to determine whether the ball loses the contact or not. Once the abnormal ball position measurement is detected, the design problem of the ball tracking sensor can be cast into the typical state estimation problem with missing data. In order to tackle the real-time implementation issue, a steady-state Kalman filter is applied to the problem. Through the experimental results, the usefulness of the proposed scheme is demonstrated.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.10a
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• pp.1-2
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• 2006

• 제어로봇시스템학회:학술대회논문집
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• 1997.10a
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• pp.1318-1321
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• 1997

A method for two-dimensional position measurement using an enclosing field has been studied and reported. The feature of this mehtod is zooming functional measurement by operating both the initial phase shift and the brightness ratio of the lighting function. An experimental system was developed and the experimental results on zooming effects are shown in this paper. This system is also an example of a "progressive learning measurement system".tem".uot;.

• Journal of Institute of Control, Robotics and Systems
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• v.16 no.10
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• pp.969-974
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• 2010

In this paper, we propose a fault-tolerant controller for compensating measurement noise of feedback sensor. Because control systems operate via feedback sensor's signal, the measurement noise in sensor's signal results in performance degradation or even system failure. Therefore, control systems often demand on compensating measurement noise. Our controller is equipped with a compensator in order to reject or reduce the effect of measurement noise in feedback information. Our proposed method is verified via simulation and experiment for a Ball and Beam system.