• Tribology and Lubricants
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• v.23 no.1
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• pp.29-36
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• 2007

It necessarily follows that wear particles are generated through a friction and wear in a mechanical moving system. The wear particles are relative to the failure and the life of machine elements directly. To analyze the wear particle, its shape characteristics were calculated quantitative values such as diameter, roundness and fractal parameters by digital image processing. In this study, the histograms of shape parameters of wear particles were used for the purpose of analyzing the distribution of wear particles in various conditions. We consider that the histogram of shape parameter can be effectively represented to study a wear mechanism.

• Proceedings of the KSME Conference
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• 2000.11b
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• pp.381-384
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• 2000

Relationships between biochemical phenomena and hemodynamics on human endothelial cells are very important to study the mechanism of atherosclerotic formation and development. The objective of this study is to investigate the flow phenomena around the endothelial cell model by the PIV experiment. The microscopic images of endothelial cells were acquired by a CCD camera to fabricate the shape of endothelial cell. The cell models were fabricated by using a photoforming process. Two consecutive particle images were captured by the CCD camera for the image processing. Conifer powder as the tracing particles was added to water to visualize the flow field. The cross-correlation method was applied fer the image processing of the flow visualization. Pressure and wall shear stress variations on the surfaces of the endothelial cells were calculated to investigate the effects of hemodynamic forces on the morphological changes.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1996.04a
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• pp.563-567
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• 1996

This paper was undertaken to analyze the morphology of wear debris generating from moving lubricated machine surfaces by image processing. The lubricating wear test was carried out under different experimentaal conditions using the wear test device was made in our laboritory and wear testing specimen of the pin on disk type wear rubbed in paraffine series base oil, byvarying applied load, sliding distance. The four parameters(50% volumetric diameter, aspect, roundness and reflectivity) to describe the morphology have been developed and are outlined in the paper. A system using such techniques promises to obviate the need for subjective, human interpretation of particle morphology in machine condition monitoring, thus overcoming many of the difficulties with current methods and facilitating wider use of wear particle analysis in machine condition monitoring.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.7 no.4
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• pp.109-114
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• 2008

The fractal dimension aims to quantitatively define the irregular characteristics of the shape in nature. It can be useful in describing morphological characteristics of various wear particles. This paper was undertaken to diagnose failure condition for sliding members in lubrication using fractal dimension. The experiments were undertaken to analyze the shape of wear particles and to diagnose failure condition for sliding members in lubrication using the image processing and the fractal parameters. It was possible to diagnose wear mechanism, friction, and damage state of machines through analysis of shape characteristics for wear particle in driven condition using fractal parameters.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.32 no.11
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• pp.963-969
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• 2008

The wear particles are relative to the failure and the life of machine elements directly. But it is not laid down to calculate shape parameters of wear particle. To analyze a variation of distributed characteristics of wear particles on moving conditions, its shape parameters such as diameter and roundness were calculated the quantitative values by digital image processing, and had to be defined the effective method of using those data. Up to the present, the shape parameters have been used simply into the average values. But these values are not effective to analyze a variation of distributed characteristics of occurred wear particles on moving conditions. In this study, the relative histograms of shape parameters of wear particles were used for the purpose of analyzing the distribution of wear particles in various conditions. The results showed that the relative histogram of shape parameters can be effectively represented to study a wear mechanism.

• Journal of the Korean Society of Marine Environment & Safety
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• v.6 no.1
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• pp.47-55
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• 2000

A three-dimensional digital image processing technique is proposed to quantitatively predict the dispersion phenomena of oil droplet onto the surface of the water. This technique is able to get the dispersion rate of an oil droplet three-dimensionally just below the surface of the water over time. The obtained dispersion rate obtained through this technique is informative to the investigation into the relationship among the gravity, surface tensions between oil, water, and air. This technique is based upon the three-dimensional PIV(Particle Imaging Velocimetry) technique and its system mainly consists of a three CCD(Charge Coupled Device) cameras, an image grabber, and a host computer in which an image processing algorithm is adopted for the acquisition of dispersion rate oil an oil droplet.

• Journal of ILASS-Korea
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• v.7 no.4
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• pp.23-31
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• 2002

In this study, the sizes and velocities of droplets in sprays were measured by image processing method from digital images of local region of sprays. The morphological method based on the Euclidean distance transform, Watershed separation, and perimeter image was adopted for the recognition and separation of overlapped particles. The match probability method was used for the particle tracking and pairing. The measurement results show that the present method may be reliable for the analysis of the motion and distribution of droplets produced by spray and atomization devices.

• Journal of the Korean Society of Visualization
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• v.2 no.1
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• pp.25-31
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• 2004

Droplet size is one of the most important parameter which controls the performance of the combustion system using liquid fuel or oxidizer. Droplet formation and its size are mainly affected by the injection velocity and ambient gas density. Recently, droplet size measurement was conducted by PDPA or Malvern particle analyzer using laser light. But at this paper image processing method was developed to measure droplet size. And its validation was investigated with reticle.

• Journal of Power System Engineering
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• v.20 no.6
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• pp.51-57
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• 2016

Experiment is carried out to investigate the mixed convective flow in three-dimensional horizontal rectangular channels filled with high viscous fluid. The particle image velocimetry(PIV) with thermo-sensitive liquid crystal tracers is used for visualizing and analysis. Quantitative data of temperature and velocity are obtained by applying the color-image processing to a visualized image, and neural network is applied to the color-to-temperature calibration. In this study, the fluid used is silicon oil(Pr=909), the aspect ratio(channel width to heigh) is 4 and Reynolds number is $2{\times}10^{-2}$. From the present study, we can visualize the quantitative temperature and velocity of mixed convective flow in three-dimensional horizontal rectangular channels simultaneously.

• Journal of Magnetics
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• v.18 no.3
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• pp.311-316
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• 2013

Digital image processing has increasingly been implemented in nanostructural analysis and would be an ideal tool to characterize the morphology and position of self-assembled magnetic nanoparticles for high density recording. In this work, magnetic nanoparticles were synthesized by the modified polyol process using $Fe(acac)_3$ and $Pt(acac)_2$ as starting materials. Transmission electron microscope (TEM) images of as-synthesized products were inspected using an image processing procedure. Grayscale images ($800{\times}800$ pixels, 72 dot per inch) were converted to binary images by using Otsu's thresholding. Each particle was then detected by using the closing algorithm with disk structuring elements of 2 pixels, the Canny edge detection, and edge linking algorithm. Their centroid, diameter and area were subsequently evaluated. The degree of polydispersity of magnetic nanoparticles can then be compared using the size distribution from this image processing procedure.