• Proceedings of the Computational Structural Engineering Institute Conference
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• 2006.04a
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• pp.127-132
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• 2006

Recently, several displacement measuring instruments such a GPS are substantially developed by development of an artificial satellite. Considering this trend, in future displacement measurement will be a very efficiency method, therefore we need to develop structure maintenance & management by using displacement measuring instruments. In this study, I suggest to maintenance & management method about simple beams and cantilever beams which are very important structurein civil engineering by using displacements. I suggest a system which trace behavior of beams by combining some measurement points and a specific displacement function and research that tl1e proper number of measurement and optimum measurement points to efficiently use the system.

• Korean Journal of Computational Design and Engineering
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• v.10 no.2
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• pp.114-120
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• 2005

This paper presents a novel method for radius measurement of fillet regions of polygonal models by using optimum onhogonal planes. The objective function for finding an optimum onhogonal plane is designed based on the orthogonality between the normal vectors of the faces in a filet region and the plane that is to be found. Direct search methods are employed to solve the defined optimization problem since no explicit derivatives of the object function can be calculated. Once an optimum orthogonal plane is obtained, the intersection between the onhogonal plane and the faces of interest is calculated, and necessary point data in the fillet region for measuring radii are extracted by some manipulation. Then, the radius of the fillet region in question is measured by least squares fitting of a circle to the extracted point data. The proposed radius measuring method could eliminate the burden of defining a plane for radius measurement, and automatically find a necessary optimum orthogonal plane. It has an advantage in that it can measure fillet radii without prior complicated segmentation of fillet regions and explicit information of neighboring surfaces. The proposed method is demonstrated trough some mea-surement examples.

• Journal of Korean Society for Quality Management
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• v.26 no.3
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• pp.60-70
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• 1998

When driving the expected loss generated by the quality deviation, Taguchi(1991b) assumed that an objective characteristic has the uniform distribution in its control limit. But it is reasonable to assume that an objective characteristic has the normal distribution than the uniform distribution. Since the triangular distribution is similar to the normal distribution and easy to handle as well, in this article, we first find the optimum measurement interval and the optimum control limit under the triangular distribution. Under the normal assumption, the modified method is compared to Taguchi's. Secondly we find the numerical value solution of the optimum measurement interval and the optimum control limit under the normal distribution.

• Proceedings of the KSR Conference
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• 2006.11b
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• pp.376-380
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• 2006

There are several methods which estimate the behavior of the Structures. Recently, several displacement measuring instruments such a GPS are substantially developed. So, considering this technique, displacement measurement will be a very efficient method for estimating the behavior of the Structures and maintenance. Therefore we need to develop methods of structure maintenance & management by using displacement measuring instruments. In this study, I suggest to maintenance & management method by using displacements about simple beams and cantilever beams which are very important structure in civil engineering. The results show that the proposed method is capable of estimating the displacement and stress of the Beam Member by combining the proper number of measurement and optimum measurement points.

• Journal of the Korean Society for Precision Engineering
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• v.18 no.6
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• pp.102-108
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• 2001

This paper addresses an analytical approach to the mechanical error analysis of gear train and tolerance design and manufacture of gear train in restricted space considering motor driving torque, driving system inertia, motor acceleration, motor rotor inertia and friction torque. The gear train is designed to have optimum gear ratio in restricted space and each gear is manufactured to have the lowest weight and each gear tooth is heat-treated to have robustness. Based on the small difference between the mechanical error analysis and measurement, gear train design with optimum gear ratio and restricted space and robustness is proposed.

• Journal of the Korea Institute of Military Science and Technology
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• v.2 no.1
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• pp.132-138
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• 1999

This paper addresses an analytical approach to the mechanical error analysis of gear train and tolerance design and manufacture of gear train in restricted space considering motor driving torque, driving system inertia, motor acceleration, motor rotor inertia and friction torque. The gear train is designed to have optimum gear ratio in restricted space and each gear is manufactured to have the lowest weight and each gear tooth is heat-treated to have robustness. Based on the small difference between the mechanical error analysis and measurement, gear train design with optimum gear ratio and restricted space and robustness is proposed

• Tunnel and Underground Space
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• v.6 no.3
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• pp.197-208
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• 1996

Due to the constraints in pre site-investigation for tunnel, it is essential to redesign the support structures suitable for rock mass conditions such as rock strength, ground water and discontinuity conditions for safe tunnel construction. For the selection of optimum support, it is very important to carry out the rock mass classification and in-situ measurement in tunnelling. In this paper, in a mountain tunnel designed by NATM in hard rock, the selectable system for optimum support has been studied. The tunnel is situated at Chun-an in Kyungbu highspeed railway line with 2 lanes over a length of 4, 020 m and a diameter of 15 m. The tunnel was constructed by drill & blasting method and long bench cut method, designed five types of standard support patterns according to rock mass conditions. In this tunnel, face mapping based on image processing of tunnel face and rock mass classification by RMR carried out for the quantitative evaluation of the characteristics of rock mass and compared with rock mass classes in design. Also, in-situ measurement of convergence and crown settlement conducted about 30 m interval, assessed the stability of tunnel from the analysis of monitoring data. Through the results of rock mass classification and in-situ measurement in several sections, the design of supports were modified for the safe and economic tunnelling.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.14 no.1
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• pp.8-13
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• 2003

In this paper, suitablility of 1 GHz CISPR limits establishment fur broadcast communication quality protection is examined and the optimum turn step resolution of EUT for spurious measurement of frequency above 1 GHz to increase the accuracy of maximum values extraction is examined. As a result of 500 MHz and 1.7 GHz clock speed personal computer of micro-processor measurement, optimum turn step resolution extracted by National Institution of National Instrument of Standard & Technology(NIST) Koepke method is estimated 40 table positions per polarization in 500 MHz. And in case of 1.7 GHz, step size is 36 table positions. Prediction of turn step size required for fully scan method in gjgahertz measurement will increase measurement accuracy and reduce considerable measurement time as well.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.14 no.9 s.90
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• pp.819-826
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• 2004

A multi-step optimum strategy for the selection of the locations and directions of strain gauges is proposed in this paper to capture at best the modal response of blade in a series of modes on fan blades. It is consist of three steps including two pass reduction step, genetic algorithm and fine optimization to find the locations-directions of strain gauges. The optimization is based upon the maximum signal-to-noise ratio(SNR) of measured strain values with respect to the inherent system measurement noise, the mispositioning of the gauge in location and gauge failure. Optimal gauge positions for a fan blade is analyzed to prove the effectiveness of the multi-step optimum methodology and to investigate the effects of the considering parameters such as the mispositioning level, the probability of gauge failure, and the number of gauges on the optimal strain gauge position.

• Journal of Sensor Science and Technology
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• v.8 no.3
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• pp.259-264
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• 1999

The $CO_2$ measuring system using infrared sensor has the variance according to the temperature change. Therefore, the temperature compensation should be needed to obtain a reliable measurement. In this study, the sensor module consist of infrared $CO_2$ Sensor, IR Source, pipe and the heater and measuring system has amplifier, A/D converter and microprocessor. And we suggest a method to reduce the error by using the PID temperature control. We use optimum parameters setting of Ziegler & Nichols as well as PID temperature control algorithm for the temperature compensation. In this method, PID optimum parameter is set from dummy time(L) and maximum slope(R). As a result of using this PID temperature control, it is founded that it has the fast response and low steady state error. Therefore, it is certainly proved that this is very suitable algorithm to correct the error on measurement.