• Journal of the Korean Society of Visualization
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• v.1 no.1
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• pp.92-97
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• 2003

A new Stereoscopic PTV was developed using two CCD cameras, stereoscopic photogrammetry based on a 3D-PTV principle. Virtual images were produced for the benchmark test of the constructed Stereoscopic PTV technique. The arrangement of the two cameras was based on angular position. The calibration of cameras and the pair-matching of the three-dimensional velocity vectors were based on the Genetic Algorithm based 3D-PTV technique. The constructed Stereoscopic PTV technique was tested on the standard images of the impinged jet proposed by VSJ. The results obtained by the constructed system showed good agreements with the original data.

• Proceedings of the KSME Conference
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• 2004.04a
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• pp.1772-1777
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• 2004

The performances of the newly constructed Stereoscopic PTV and Stereoscopic PIV which had been completed based on a 3D-PTV principle are tested using the Standard Images. Virtual images were produced for the benchmark tests of the constructed two Stereoscopic techniques. The arrangement of the two cameras was based on angular position. The calibration of cameras and the pair-matching of the three-dimensional velocity vectors were based on Genetic Algorithm based 3D-PTV technique. The Standard data of LES are on the impinged jet proposed by VSJ. It is shown that the results obtained by Stereoscopic PTV have better reliability than those by Stereoscopic PTV.

• 한국가시화정보학회:학술대회논문집
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• 2002.11a
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• pp.11-14
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• 2002

A new high-definition stereoscopic PTV was constructed using two CCD cameras, stereoscopic photogrammetry based on a 30-PTV principle. The arrangement of the two cameras was based on angular position. The calibration of cameras and the pair-matching of the three-dimensional velocity vectors were based on Genetic Algorithm based 30-PTV technique. The constructed Stereoscopic PTV technique was tested on the standard images of the Impinging jet proposed by VSJ. The results on the turbulent properties of the jet obtained by the constructed system showed a good agreement with the original LES data.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.30 no.3 s.246
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• pp.215-221
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• 2006

A stereoscopic particle tracking velocimetry (SPTV) technique based on the 2-frame hybrid particle tracking velocimetry (PTV) method was developed. The expansion of 2D PTV to SPTV is facilitated by the fact that the PTV method tracks individual particle centroids. To evaluate the performance and measurement accuracy of the present SPTV technique, it was applied to flow images of rigid body translation and synthetic standard images of jet shear flow and impinging jet flow. The data processing routine and measurement uncertainty of the SPTV technique are compared with those of conventional stereoscopic particle image velecimet.y (SPBV). In addition, the centroid translation effect of 2D particle image velocimetry (PIV) is defined and its effect on SPIV measurements is discussed. Compared to the SPIV method, the SPTV technique has inherited merits of concise and precise velocity evaluation procedures and provides better spatial resolution and measurement accuracy.

• The Journal of Korean Society for Radiation Therapy
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• v.22 no.2
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• pp.131-134
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• 2010

Purpose: TOMO therapy treatment for a relatively long run Beam time and temperature-sensitive detector, such as CT clinics in optimal temperature ($20~21^{\circ}$) to maintain a constant temperature in addition to its own Chamber Cooling system is activating. TOMO This clinic has been reduced in the patients' body temperature to keep the sheets and covers over the treated area. Therefore, these materials for any changes in the organization gives the dose were analyzed. Materials and Methods: To compare changes in the organization Dose Phantom cheese (Cheese Phantom) were used, CT-simulation taking the center point of the cheese phantom PTV (Planning Target Volume, treatment planning target volume) by setting Daily dose 200 cGy, 3 meetings planned treatment. PTV, PTV +7 cm, PTV +14 cm, the total count points on the phantom using the Ion chamber cover without any substance to measure the dose, and one of the most commonly used treatment, including the frequently used four kinds of bedding materials (febric 0.8 mm, gown 1.4 mm, rug, 3.3 mm, blanket 13.7 mm) and covered with a phantom and the dose measured at the same location were analyzed 3 times each. Results: PTV, PTV +7 cm, PTV +14 cm from the point of any substance measured in the state are covered with four kinds of materials (fabric, gown, rug, blanket) was measured in the covered states and compares their results, PTV respectively -0.17%, -0.44%, -0.53% and -0.9% change, PTV +7 cm, respectively -0.04%, +0.07%, +0.06%, +0.07%, were changed, PTV +14 cm, respectively 0%, -0.06%, -0.02%, +0.6%, respectively. Conclusion: These results TOMO treatment to patients to maintain their body mass by using PTV thickness of the material decreased in proportion to. PTV +7 cm, but showed slight changes in the point, PTV +14 cm at the point of the dose was increased a little. Sejijeom all the difference in treatment tolerance ${\pm}3%$ range, this is confirmed in the coming treatment will not affect the larger should be considered.

• 한국전산유체공학회:학술대회논문집
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• 2008.03b
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• pp.88-91
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• 2008

A Hybrid-Genetic-Algorithm based 3D-PTV has been constructed by introducing the conventional GA-3D-PTV. The measurement system consists of two-high-definition-cameras(1k ${\times}$ 1k), a Nd-Yag laser and a host computer. The system has been used to measure the wake of a cylinder. The Reynolds number is 1120. The structures of the wake have been quantified in detail than the results obtained ever before.

• Journal of the Korean Society of Visualization
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• v.8 no.4
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• pp.26-30
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• 2010

A PTV algorithm was constructed using a linear transformation, in which the merits of the conventional PIV and PTV were adopted. In PIV calculations, the obtained velocity vectors are affected by the filtering effects by its calculation principle. PTV techniques are widely used for their excellences of measuring small scaled flows, such as nano and bio flows. However, PTVs produce vector errors due to interpolation process. To overcome these problems, a hybrid PTV algorithm was constructed by combining PTVs' and PIVs' benefits using a linear transformation. The Taylor-Green vortex flows were generated for the tests of vorticity calculations. The conventional gray-level cross-correlation PIV technique and 2-Frame PTV technique were tested for the same flows for comparisons with those obtained by the constructed hybrid algorithm. The excellence of the constructed hybrid algorithm was validated through an actual experiment on the cylinder wake.

• Journal of Korea Water Resources Association
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• v.34 no.4
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• pp.327-333
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• 2001

Particle tracking velocimetry (PTV) is introduced and applied to the fall-velocity measurement. The fall velocities of sediment particles were measured using PTV in the still water and compared with the values presented in the existing literature. Comparison shows that PTV measures the fall velocities accurately. This result enables the measurement of fall velocity in the turbulent flows, which was not possible with conventional methods.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.22 no.6
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• pp.874-887
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• 1998

A 2-frame PTV (particle tracking velocimetry) system using the concept of match probability between two consequent image frames has been developed to obtain instantaneous velocity fields. The overall 2-frame PTV system including image pre-processing, tracking algorithm and post-processing routine was implemented to apply to real flows. The developed 2-frame PTV system has several advantages such as high recovery ratio of velocity vectors, low error ratio and small computational time compared with the conventional 4-frame PTV and the FFT-based cross-correlation PIV technique. The 2-frame PTV system was applied to a turbulent channel flow over a rectangular block to check its reliability and usefulness. Total 96 sequential image frames have been captured and processed to get both mean and fluctuating velocity vector fields over the recirculating region. The mean velocity and turbulent intensity profiles were well agreed with hte LDV measurements in the separated region behind the block. Time-averaged reattachment length is about 6.3 times of the block height.

• Proceedings of the KSME Conference
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• 2002.08a
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• pp.511-512
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• 2002

A new stereoscopic PTV was developed using two CCD cameras, stereoscopic photogrammetry based on a 3D-PTV principle. The arrangement of the two cameras was based on angular position. The calibration of cameras and the pair-matching of the three-dimensional velocity vectors were based on Genetic Algorithm based 3D-PTV technique. The constructed Stereoscopic W technique was tested on the standard images of the impinged jet proposed by VSJ. The results on the turbulent properties of the jet obtained by the constructed system showed a good agreement with the original LES data.