• The Journal of the Acoustical Society of Korea
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• v.33 no.5
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• pp.291-299
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• 2014

To probe the temperature elevation effect caused by ultrasound, a tissue mimicking phantom was newly suggested. A carrageenan gel was adopted to realize not only the required transparency for visualization but also acoustic characteristics similar to human tissue. To visualize the temperature elevation inside phantom, thermochromic film with a critical temperature of discoloration was introduced. Acoustic characteristics of the tissue mimicking phantom were examined when the concentrations of carrageenan and sucrose changed. As the results, the attenuation coefficient of the phantom could be controlled in the range of 0.44~0.49 dB/cm/MHz, and the acoustic impedance in the range of 1.52~1.77 Mrayls. We could control the acoustic characteristics of the phantom by different concentration of carrageenan and sucrose, and it was possible to examine the temperature elevation caused by ultrasound in the phantom. The suggested method was verified by noninvasively visualizing the temperature elevation due to planar and focused ultrasound using the fabricated phantom.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.5
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• pp.1947-1955
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• 2013

The purpose of this paper is to present an photoelasticity technique for measuring the displacement and stress distribution in particle assembly subjected to shallow foundation loading. Photoelastic measurement technique was employed to visualize the force transmission of a particle assembly. A model assembly bounded by a steel frame was built by stacking bi-dimensional circular particles made of polycarbonate elastomer. Each particle was coated by a thin photoelastic sheet so that the force transmission represented by bright light stripes can be visualized. In a contacted particle, both magnitude and orientation of principal stress difference can also be measured via the photoelasticity technique. The different distributions of the contact stresses at the initial loading and near the failure were quantitatively compared. The photoelastic patterns and displacement fields observed in the pre-failure state disappears immediately after the buckling of confined force chains.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.35 no.5
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• pp.487-490
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• 2011

We used X-ray tomography to carry out an experimental study to visualize the effect of freeze and thaw cycles on the gas diffusion layer (GDL) in a polymer electrolyte membrane fuel cell (PEMFC). A PEMFC has freeze and thaw cycles if the fuel cell is operating at a below-freezing ambient temperature. The cycle permanently deforms the fuel-cell capillary structures and reduces the ability of the cell to generate electric power and also reduces its service life. The GDL is the thickest capillary layer in the fuel cell, so it experiences the most deformation. The X-ray tomography facility at the Pohang Accelerator Laboratory was used to observe the structural changes in GDLs induced by a freeze and thaw cycle. We discuss the effects of these structural changes on the power production and service life of PEMFCs.

• Journal of Korean Neurosurgical Society
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• v.58 no.5
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• pp.494-498
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• 2015

Objective : To describe a novel spinous process-splitting hemilaminoplasty technique for the surgical treatment of intradural and posterior epidural lesions that promotes physiological restoration. Methods : The spinous process was split, the area of the facet lamina junction was drilled, and en bloc hemilaminectomy was then performed. After removing intradural and posterior epidural lesions, we fitted the previously en bloc-removed bone to the pre-surgery same shape, and held it in place with non-absorbable sutures. Surgery was performed on 16 laminas from a total of nine patients between 2011 and 2014. Bony union of the reconstructed lamina was assessed using computed tomography (CT) at 6 months after surgery. Results : Spinous process-slitting hemilaminoplasty was performed for intradural extramedullary tumors in eight patients and for ossification of the ligament flavum in one patient. Because we were able to visualize the margin of the ipsilateral and contralateral dura, we were able to secure space for removal of the lesion and closure of the dura. None of the cases showed spinal deformity or other complications. Bone fusion and maintenance of the spinal canal were found to be perfect on CT scans. Conclusion : The spinous process-splitting hemilaminoplasty technique presented here was successful in creating sufficient space to remove intradural and posterior epidural lesions and to close the dura. Furthermore, we were able to maintain the physiological barrier and integrity after surgery because the posterior musculature and bone structures were restored.

• Proceedings of KOSOMES biannual meeting
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• 2006.11a
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• pp.213-215
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• 2006

This study presents an application of GIS technologies to construct the graphic user interface for 3-dimensional exhibition of the results obtained by ocean hydrodynamic model. In coastal management studies, GIS provide a receptacle for scattered data from diverse sources and an improvement of the 3D visualization of such data. Within the frame of a GIS a variety of analytical, statistical and modeling tools can be applied to transform data and make them suitable for a given application. A 3D hydrodynamic model was driven by time-dependent external forcing such as tide, wind velocity, temperature, salinity, river discharge, and solar radiation under the open boundary condition. The Jinhae Bay was selected as a case study. Here, we have used GeoMania v2.5 GIS software and its 3D Analyst extension module to visualize hydrodynamic model result that were simulated around the Jinhae Bay.

• Journal of the Korean Applied Science and Technology
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• v.36 no.4
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• pp.1219-1223
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• 2019

The skin condition varies by the parts of the face. This study intended to visualize the facial skin based on the characteristics including moisture, sebum, dryness, amount of dead skin cells, and roughness by sectionalizing the facial skin into 9 areas. A total of 98 female in their 20~35s were selected, and the characteristics of skin by area were selected and listed in the order, and the area they felt each characteristic most strongly was analyzed with a weight and the result was visualized. The result showed that the area where they felt dryness the most was around the lips and eyes, and the area where the largest amount of dead skin cells and rough skin existed was the chin. There was a significant increase in moisture content (p <.05), and 90.5% of satisfaction with dryness was satisfied. The result of this study will be used as a basic data for the development of a cosmetic mask pack or a functional cosmetic product for each part.

• Journal of the Korean Association of Geographic Information Studies
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• v.7 no.3
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• pp.99-107
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• 2004

This study presents an application of GIS technologies to construct the graphic user interface for 3-dimensional exhibition of the results obtained by ocean hydrodynamic model. In coastal management studies, GIS provide a receptacle for scattered data from diverse sources and an improvement of the 3D visualization of such data. Within the frame of a GIS a variety of analytical, statistical and modeling tools can be applied to transform data and make them suitable for a given application. A 3D hydrodynamic model was driven by time-dependent external forcing such as tide, wind velocity, temperature. salinity, river discharge, and solar radiation under the open boundary condition. The Jinhae bay was selected as a case study. Here, we have used GeoMania v2.5 GIS software and its 3D Analyst extension module to visualize hydrodynamic model result that were simulated around the Jinhae bay.

• Journal of Advanced Marine Engineering and Technology
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• v.39 no.5
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• pp.570-576
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• 2015

3D visualization of navigation simulation is to visualize the environment conditions (e.g. nearby ships, dynamic characteristics, environment, terrain, etc) for any users on ships at sea. Realistic 3D visualization enables the users to be immersed to it and guarantees the reliability of the simulation. In particular, terrain visualization contains many virtual objects, so it is time and cost-intensive for object modelling. This paper proposes a 3D terrain visualization method that can be realized in a short time and with low cost by using the Unity 3D development tool. The 3D terrain visualization system requires bathymetric and elevation terrains, and Aids to Navigations (AtoNs) to be realized. It also needs to include 3D visualization objects including bridges, buildings and port facilities for more accurate simulation. Bathymetric and AtoN elements are acquired from ENC, and the elevation element is acquired from SRTM v4.1 digital elevation chart database developed by NASA. Then, the bathymetric and elevation terrains are generated, and the satellite images are superposed by using this terrain information. The longitudinal and latitudinal information of the AtoNs are converted to the 3-axis information to position the AtoN locations. The 3D objects such as bridges, buildings and port facilities are generated and the terrain visualization is completed. The proposed method realizes more realistic 3D terrain visualization of Busan Port.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.38 no.5
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• pp.381-388
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• 2014

Our aim was to simulate ocean waves in a small-size wave flume and observe the motion of a cylindrical floating body placed in an offshore environment. To precisely visualize the oscillation of the body, a set of light-emitting diode illuminators and high-speed charge-coupled device camera were installed in the flume. Spectral analysis was performed of the movement of the floating body. The wave generator and absorbers worked well to simulate stable regular waves. As the period of the oncoming waves changed, the movement of the floating body substantially differed when tethered to a tension-leg mooring cable. In particular, when connected to the tension-leg mooring cable, the natural frequency of the floating body suddenly appeared at 0.391 Hz as the wave period was increased.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.29 no.5
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• pp.405-411
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• 2016

This paper presented the theory related to a two dimensional linear cross-sectional analysis, recovery relationship and a one-dimensional nonlinear beam analysis for composite beam with initial twist and high aspect ratio. Using VABS including related theory, preceding research data of the composite wing structure has been modeled and compared. Cross-sectional analysis was performed and 1-D beam was modeled at cutting point including all the details of real geometry and material. The 3-D strain distribution and margin of safety at recovery point was calculated based on the global behavior of the 1-D beam analysis and visualize numerical results.