• Proceedings of the KSME Conference
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• 2002.08a
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• pp.471-474
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• 2002

A new stereoscopic PIV has been constructed using two CCD cameras, stereoscopic photogrammetry, and 3D-PTV principle. The capability of the developed stereoscopic PIV was verified through a test on the Standard Images which are provided on the website of VSJ. The arrangement of the two cameras was based on angular position For the acquisition of 3D velocity vectors, 2D velocity vectors were obtained using the gray-level cross-correlation method from the two camera images and they were matched stereoscopically. The wake of a circular cylinder was measured and turbulent properties were presented.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.23 no.1
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• pp.123-130
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• 1999

The objective of the current study is to understand steady 3-dimensional flow phenomena in a bifurcated duct experimentally. A bifurcation model is fabricated with transparent acrylic resin to visualize the whole flow field with the PIV system. The gray level cross-correlation method is applied to the image processing algorithm. The subpixel and the area interpolation methods are used to obtain the final velocity vectors. The finite volume predictions are used to analyze the flow patterns in the bifurcation model. The results of the computer simulation and the PIV experiment for three-dimensional flow show the recirculation zone and the formation of the paired secondary flow distal to the apex of the bifurcation model. The results obtained with the two methods also show that the branch flow strongly strikes the inner wall due to the inertial effect and accompanied helical motion as it flows toward the outer wall.

• Journal of the Korean Society of Industry Convergence
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• v.6 no.4
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• pp.373-378
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• 2003

An experimental investigation was performed to study the characteristics of laminar water flow in a horizontal circular tube by using liquid crystal. A simultaneous measurement technique has been employed to measure the temperature field in a two-dimensional cross section of fluid flow. This study found the temperature distribution for Re =900~1,500 along longitudinal sections and the results appear to be physically reasonable. To determine some characteristics of the laminar flow, 2D PIV technique is employed for temperature measurement and liquid crystal is used for heat transfer experiments in water. The experimental rig was manufactured from an acryle tube. The test tube diameter of 25mm, and a length of 1200mm. The used algorithm is the gray level cross-correlation method by using Kimura et al. in 1986.

• Journal of the Korean Society of Industry Convergence
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• v.7 no.1
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• pp.19-24
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• 2004

An experimental investigation was performed to study the characteristics of laminar water flow in a horizontal circular tube by using liquid crystal. A simultaneous measurement technique has been employed to measure the velocity field in a two-dimensional cross section of fluid flow. This study found the velocity distributions for Re = 1,594 ~ 2,510 along longitudinal sections and the results appear to be physically reasonable. To determine some characteristics of the laminar flow, 2D PIV technique is employed for velocity measurement by using liquid crystal in water. The experimental rig was manufactured from an acryle tube. The test tube diameter of 25mm, and a length of 1200mm. The used algorithm is the gray level cross-correlation method by using Kimura et al. in 1986.

• 유체기계공업학회:학술대회논문집
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• 1999.12a
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• pp.264-271
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• 1999

The present experimental study is aimed to investigate the flow characteristics of the high-speed flow field within hot-water pump by PIV(Particle Image Velocimetry). As multi-point simultaneous velocity acquisition, 2-D PIV system based upon the two-frame gray-level cross correlation method is adopted using PC frame-grabber and simple video system. Gated image intensifier CCD Camera to cope with illumination problem is arranged for accurate PIV measurement of high-speed complex flow. The velocity vector distribution, velocity profile, and kinetic energy are represented quantitatively at the full-scale region for the deeper understanding of the unsteady flow characteristics in a pump.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.22 no.7
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• pp.956-962
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• 2018

As the study of the object feature detection from image, we explain methods to identify the species of the tree in forest using the picture taken from dron. Generally there are three kinds of methods, which are GLCM (Gray Level Co-occurrence Matrix) and Gabor filters, in order to extract the object features. We proposed the object extraction method using the statistical properties of trees in this research because of the similarity of the leaves. After we extract the sample images from the original images, we detect the objects using cross correlation techniques between the original image and sample images. Through this experiment, we realized the mean value and standard deviation of the sample images is very important factor to identify the object. The analysis of the color component of the RGB model and HSV model is also used to identify the object.