• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.04a
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• pp.73-77
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• 1997

This paper describes the analysis of measuring error of on the machine measuring(OMM) system which can directly measure the three dimensional machined free surface dimension using scanning probe on milling machine. 21 inch TV shadow mask mould was measured using PTP(point to point)measurement algorithm at pallet clamped and unclamped state on OMM system, and using coordinate measuring machine(CMM) one after another. The OMM system was evaluated probe error, stylus contact error, center shift error, repeatability and so on. Consequencely, the conclusion derived that elastic displacement of pallet had effect on measuring error mainly, and pallet design and setup method would be important.

• The Journal of Korean Society for Radiation Therapy
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• v.9 no.1
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• pp.71-81
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• 1997

I. Objective and Importance of the Project We have been using MC-50 cyclotron and NT-50 neutron therapy machine for treating cancer patients since 1986 at Korea Cancer Center Hospital. It is mandatory to measure accurately the dose distribution and the total absorbed dose of fast neutron for putting it to the clinical use. At present the methods of measurement of fast neutron are proposed largely by American Associations of Physicists in Medicine (Task Group 18), European Clinical Neutron Dosimetry Group, and International Commission on Radiation Units and Measurements. The complexity of measurement, however, induce the methodological differences between them. In our study, therefore, we tried to establish a unique technique of measurement by means of measuring the emitted doses and the dose distribution of fast neutron beam from neutron therapy machine, and to invent a standard method of measurement adequate to our situation. II. Scope and Contents of the Project For establishing a unique technique of measurement and inventing a standard method of measurement of fast neutron beam, 1. to grasp the physical characteristics of neutron therapy machine 2. to study the principles for measrement of fast neutron beam 3. to get the dose distribution (dose rate, percent-depth dose, flatness etc) throught the actual measurement 4. to compare our data with those being cited world-widely.

• 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.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.8 no.6
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• pp.55-63
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• 1999

The acceleration of the performance of machine tools influences the development of the semi-conductor and optical technology as the development of NC and measurement technology. Because the measurement has been done to unload condition without considering of mechanical stiffness in the case of machining center as we measure the quasi-static error of machine tools on general study people who works on the spot has many problems on the data value. Also there are no satisfiable results until now in spite of many studys about this because the deflections of the table and the shaft supporting a workpiece influence, influence the accuracy of the table and shaft supporting a workpiece influence the accuracy of the workpiece. And there is doubt about the inspection method of measured error. In this paper Therefor we will help working more accurately on the spot by measuring analyzing displaying the defoec-tion of the table and support shaft when we load on the table and the support shaft of machining center using laser interfer-ometer. Also we try to settle new conception of the measurement method and more accurate grasp of the deflection tenden-cy by verifing the tendency of the error measured through the comparison of the simulated error measured through the comparison of the simulated error using ANSYS a common finite element analysis program which is able to measure heat deformation material deformation and error resulted from this study.

• Journal of the Korean Society for Precision Engineering
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• v.15 no.5
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• pp.93-99
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• 1998

Although laser interferometer measurement system has advantages of measurement range and accuracy, it has some disadvantages when measurement of multi degrees of freedom of motion are required. Because the traditional error measurement methods for geometric errors (two straightness and three angular errors) of a slide of machine tools measures error components one at a time. It may also create an optical path difference and affect the measurement accuracy. In order to identify and compensate for geometric errors of a moving rigid body in real time processes, an on-line error measurement system for simultaneous detection of the five error components of a moving object is required. Using laser alignment technique and some optoelectronic components, an on-line measurement system with 5 degrees of freedom was developed for the geometric error detection in this study Performance verification of the system has been performed on an error generating mechanism. Experimental results show the feasibility of this system for identifying geometric errors of a slide of machine tools.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.13 no.1
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• pp.16-22
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• 2014

Resonance refers to the magnification of a structural response which occurs when a linear lightly damped system is driven with a sinusoidal input at its natural frequency. An exploratory vibration test (a natural frequency measurement test) is very important for the vibration testing of machine parts, as the value measured in an actual laboratory affects test results. For this reason, it is necessary to estimate the measurement uncertainty to verify the reliability of this type of test. In this study, measurement uncertainty is estimated based on three uncertainty factors. The uncertain factors are the measured points in the machine parts, the resolution of the vibration equipment, and uncertainty of the calibration certificate.

• 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.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 1999.05a
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• pp.63-68
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• 1999

A 2$\frac{1}{2}$ dimensional measurement and inspection system realized on the machine tool using a touch trigger probe and measuring G codes is synthesized in this paper. Measuring G codes have been constructed according to geometric farms, precision attributes, relationships between two parts, datum hierarchies, and relevant technological data by using measuring arguments. Algorithms far calibration and compensation of measuring errors are proposed to ensure the measuring accuracy by using a laser interferometer and ring gauges. Classification of feed rates according to the objectives of movement makes it possible to reduce measuring time and also implement collision-free measurement. Experiments are conducted to verify the validity and effectiveness of proposed methods.

• Transactions of the Korean Society of Mechanical Engineers
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• v.13 no.3
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• pp.443-450
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• 1989

A digital testing method for measurement of radial error motions of a spindle is investigated with special emphasis on developing a computer-aided in-situ inspection for machine tool manufacturing. The method utilizes three non-contact type probes and an optical encoder, based on a special computational algorithm to eliminate undesirable offset and roundness errors of the master spindle. Details of the design of hardware and software required to realize the testing method are described. Finally, advantages and limitations of the method are discussed with several test results.

• International Journal of CAD/CAM
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• v.12 no.1
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• pp.1-8
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• 2012

This study analyzes the characteristics of two different kinds of squat exercise through physical experiments and a computer simulation, i.e. one with a free weight and the other with a Smith machine are studied. This study also proposes a new design for the Smith machine, which has both the advantages of each type based on the results of the analysis. The muscle force and level of stimulation of the lower extremities during squatting were calculated by running an inverse dynamics analysis program on a musculoskeletal model together with the measured motion data. The calculated results were verified by comparing with the measured EMG data. The analysis showed that squatting using free weight is more effective than squatting using the Smith machine. Meanwhile, in order to design an improved Smith machine, which is the final goal of this study, the trajectory of the barbell of the subjects during free weight squatting was measured on the sagittal plane. The measurement showed that the average slope of the trajectory of the barbell is tilted backward by $10.7^{\circ}$. Based on this measurement, this study proposes a tilted design for an improved Smith machine.