• International Journal of Vascular Biomedical Engineering
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• v.2 no.2
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• pp.27-32
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• 2004

The objective of the present study is to visualize the steady and pulsatile flow fields in a branching model by using a high-resolution PIV system. A bifurcated flow system was built for the experiments in the steady and pulsatile flows. Harvard pulsatile pump was used to generate the pulsatile velocity waveforms. Conifer powder as the tracing particles was added to water to visualize the flow fields. CCD cameras($1K{\times}1K$(high resolution camera) and $640{\times}480$(low resolution camera)) captured two consecutive particle images at once for the image processing of several cross sections on the flow system. The range validation method and the area interpolation method were used to obtain the final velocity vectors with high accuracy. The results of the image processing clearly showed the recirculation zones and the formation of the paired secondary flows from the distal to the apex of the branch flow in the bifurcated model. The results also indicated that the particle velocities at the inner wall moved faster than the velocities at the outer wall due to the inertial force effects and the helical motions generated in the branch flows as the flow proceeded toward the outer wall. Even though the PIV images from the high resolution camera were closer to the simulation results than the images from the low resolution camera at some locations, both results of the PIV experiments from the two cameras generally agreed quite well with the results from the computer simulations. Therefore, instead of using the expensive stereoscopic PIV or 3D PIV system, the three-dimensional flow fields in a bifurcated model could be easily and exactly investigated by this study.

• Journal of the Korean Society of Radiology
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• v.15 no.1
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• pp.45-54
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• 2021

This study was written to create educational content in non-destructive fields based on Mixed Reality. Currently, in the field of radiation, there is almost no content for educational Mixed Reality-based educational content. And in the field of non-destructive inspection, the working environment is poor, the number of employees is often 10 or less for each manufacturer, and the educational infrastructure is not built. There is no practical training, only practical training and safety education to convey information. To solve this, it was decided to develop non-destructive worker education content based on Mixed Reality. This content was developed based on Microsoft's HoloLens 2 HMD device. It is manufactured based on the resolution of 1280 ⁎ 720, and the resolution is different for each device, and the Side is created by aligning the Left, Right, Bottom, and TOP positions of Anchor, and the large image affects the size of Atlas. The large volume like the wallpaper and the upper part was made by replacing it with UITexture. For UI Widget Wizard, I made Label, Buttom, ScrollView, and Sprite. In this study, it is possible to provide workers with realistic educational content, enable self-directed education, and educate with 3D stereoscopic images based on reality to provide interesting and immersive education. Through the images provided in Mixed Reality, the learner can directly operate things through the interaction between the real world and the Virtual Reality, and the learner's learning efficiency can be improved. In addition, mixed reality education can play a major role in non-face-to-face learning content in the corona era, where time and place are not disturbed.