• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
• /
• 1999.11a
• /
• pp.103-113
• /
• 1999

Point contact film thickness in elastohydrodynamic lubrication (EHL) is analyzed by the image processing method for the monochromatic incident light. Interference between the reflected lights both on Cr coating of glass disk and on super finished ball makes circular fringes, which are regarded as film thickness together with numbering of fringe order. In this study, we developed technology to measure the film thickness by analyzing dark and bright intensity waves which results from monochrome green light. Two typical fringe patterns only with intensity values 3re examined for the measurement of point contact EHL film thickness. We expect that this technology will give valuable clue to improve color image processing analysis for high resolution of EHL film thickness with white incident light.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2002.05a
• /
• pp.253-259
• /
• 2002

The rigid body characteristics (value of mass, Position of center of mass, moments and products of inertia) of mechanical systems can be identified from FRF data or vibration spectra of rigid body motion. Therefore the accuracy of rigid body characteristics is connected directly with the accuracy of measured data for rigid body motions. In this paper, a method of improving accuracy of measurement of rigid body motion is presented. Applying rigid body theory, ail translational and rotational displacements at a tentative point on the rigid body are calculated using the measured translational displacements for several points and transfer matrix. Then the estimated displacements for the identical points are calculated using the 6 displacements of the tentative Point and transfer matrix. By using correlation coefficient between measured and estimated displacements, we can detect the existence of errors that are contained in a certain measured displacement. Consequently, the improved rigid body motion with respect to a tentative point can be obtained by eliminating the contaminated data.

• Journal of the Korean Society for Precision Engineering
• /
• v.12 no.4
• /
• pp.119-126
• /
• 1995

This paper presents a non-contact measuring system using one point measuring method to measure surface profiles of dies and clay models for practical use in the field of production engineering. The system has a laser beam probe similar to a measuring probe in a contact measuring system and CCD linear sensor used to detect 300mm measurement range, displacement of measured surfaces, from an origin. There is no mechanical interference between this measuring system and a measured surface in this system. In this measuring system, it was needed 500-600ms including data processing time to measure one point. The experiments showed that the standard deviation was 800 .mu.m and the reproducibility was also 100-210 .mu. m.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2007.11a
• /
• pp.442-445
• /
• 2007

A noise reduction policy can be more effectively made when automatic environmental noise measurement system is set up. However, the local characteristic of noise pollution requires a lot of measurement points. This study considers that automatic environmental noise measurement system connects with automatic air pollution measurement system and noise map. The measurement points of traffic volume by the National Police Agency and the Ministry of Construction and Transportation are investigated to use at drawing the road traffic noise map. Finally, the effective application method of the environmental noise measurement vehicle is discussed.

• Proceedings of the Korean Society for Quality Management Conference
• /
• 2006.11a
• /
• pp.199-204
• /
• 2006

ANOVA is widely used for measurement system analysis. It assumes that the measurement error is normally distributed, which may 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 for 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.

• Journal of the Korean Institute of Intelligent Systems
• /
• v.24 no.4
• /
• pp.424-429
• /
• 2014

In this paper, an image-based luminance measurement system(LMS) is proposed to measure the luminance of outdoor signboards. We design the LMS that can improve disadvantages of efficiency of the point-luminance meter and portability of face-luminance meter using the image of DSLR camera and print out the luminance value by using the proposed luminance analysis algorithm in real time. Outdoor signboards have various size and shape, and are also installed on the various place. Luminance of the signboard is influenced by measurement location, angle, color, etc. Therefore, we measure the change of luminance value in accordance with measurement location for accurate luminance measurement and then consider the luminance value according to the measurement distance. We obtain a numerical relation between luminance value and measurement location. The proposed LMS is verified through comparative experiment with point-luminance meter.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.41 no.10
• /
• pp.949-957
• /
• 2017

A laser-vision-based height measurement system is developed and implemented for the inspection of two-step variable valve lift module assemblies. The proposed laser-vision sensor module is designed based on the principle of laser triangulation. This paper summarizes the work on 3D point cloud data collection and height difference measurements. The configuration of the measurement system and the proposed height measurement algorithm are described and analyzed in detail. Additional measurement experiments on the height differences of valves and lash adjusters of a two-step variable valve lift module were implemented repeatedly to evaluate the accuracy and repeatability of the proposed measurement system. Experimental results show that the proposed laser-vision-based height measurement system achieves high accuracy, repeatability, and stabilization for the inspection of two-step variable valve lift module assemblies.

• Journal of the Korean Society of Radiology
• /
• v.15 no.1
• /
• pp.85-91
• /
• 2021

The purpose of this study is to derive an equation to verify the accuracy of the dose rate for each component calculated at the measurement point outside the maze door when designing the maze door of 6 MV X-ray beam. Based on the component-specific dose rate calculation formula for the measurement point outside the maze door described in NCRP Report 151 and IAEA Safety Report Series 47, the dose rate calculation formula for each component when applying the values of the drawing-based parameters and the dose rate calculation formula for each component when applying the values of conservative parameters are derived. From the two dose rate calculation formulas for each component, the dose rate verification formula for each component at the measurement point outside the maze door was derived. The resulting dose rate verification formula for each component at the measurement point outside the maze door can be compared and analyzed whether the dose rate for each component at the measurement point outside the maze door calculated by the designer falls within the range of the dose rate obtained from the derived dose rate verification formula for each component. This verification formula is considered to be practically useful in verifying the accuracy of the dose rate for each component calculated by the designer.

• 한국가시화정보학회:학술대회논문집
• /
• 2001.12a
• /
• pp.62-74
• /
• 2001

Present paper describes the principles of PIV measurement approaching from the analytical view, which enables to explain the general form of principles covering all the PIV measurement, and that gives theoretical basis for its higher measurement performances. The explanation of the measurement principles started from the definition of governing equation in differential form as same as the gradient method, and the integral along the particle path line was executed to show the principle of the correlation method with same basis. The integral processes clearly shows the analytical reason why the correlation peak gives the terminal point of path line, and how the effects of deformation and rotation of fluid appears in the correlation map. These results have no differences from our experiences and understandings of the conventional PIV measurement definition in final form. However, the analytical approach enable to understand those facts a priori, and it makes easy to achieve the innovative higher performances of measurement. Analytical explanation clearly shows the behavior of the residual errors caused by the fluid motion, and it enables to analyze the measurement uncertainty theoretically.

• International conference on construction engineering and project management
• /
• 2009.05a
• /
• pp.1479-1484
• /
• 2009

It is commonly recognized to need performance management for successful construction project. PPC measurement of Last Planner System is one of construction project measurement method. PPC measurement is quantitatively assessment to go through construction, and that is not completely to be trusted when compare a project with another or an individual case work with another in same project. According to, purpose of this study is comparison indicator establishment that compare project with another or an individual case work with another it is not use PPC measurement for quantitatively assessment to go through construction. The procedure of this study is derive of the point at issue of existing PPC measurement for a aim PPC measurement in this study expenditure and select weight about that and it is applied to actually construction.