• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.5C
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• pp.716-725
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• 2004

In this paper, a new multiview stereoscopic 3D display system using a VHLS(volume holographic lenticular sheet) is suggested. The VHLS, which acts just like an optical direction modulator, can be implemented by recording the diffraction gratings corresponding each directional vector of the multiview stereoscopic images in the holographic recording material by using the angularly multiplexed recording property of the conventional volume hologram. Then, this fabricated VHLS is attached to the panel of a LCD spatial light modulator and used to diffract each of the multiview image loaded in a SLM to the corresponding spatial direction for making a 3D stereo view-zone. Accordingly, in this paper, the operational principle and characteristics of the VHLS are analyzed and an optimized 4-view VHLS is fabricated by using a commercial photopolymer. Then, a new VHLS-based 4-view stereoscopic 3D display system is implemented. Through some experimental results using a 4-view image synthesized with adaptive disparity estimation algorithm, it is suggested that implementation of a new VHLS-based multiview stereoscopic 3D display system can be possible.

• Journal of Multimedia Information System
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• v.5 no.1
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• pp.35-42
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• 2018

Direct volume rendering (DVR) is an important 3D visualization method for medical images as it depicts the full volumetric data. However, because DVR renders the whole volume, regions of interests (ROIs) such as a tumor that are embedded within the volume maybe occluded from view. Thus, conventional 2D cross-sectional views are still widely used, while the advantages of the DVR are often neglected. In this study, we propose a new visualization algorithm where we augment the 2D slice of interest (SOI) from an image volume with volumetric information derived from the DVR of the same volume. Our occlusion-based DVR augmentation for SOI (ODAS) uses the occlusion information derived from the voxels in front of the SOI to calculate a depth parameter that controls the amount of DVR visibility which is used to provide 3D spatial cues while not impairing the visibility of the SOI. We outline the capabilities of our ODAS and through a variety of computer tomography (CT) medical image examples, compare it to a conventional fusion of the SOI and the clipped DVR.

• Journal of the Korea Computer Graphics Society
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• v.8 no.3
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• pp.1-7
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• 2002

This paper presents a practical technique for approximating the boundary surface of the volume swept out by three-dimensional objects using the depth-buffer. Objects may change their geometries and orientations while sweeping. The sweep volume is approximated as a union of volume elements, which are just rendered inside appropriate viewing frusta of virtual cameras and mapped into screen viewports with depth-buffer. From the depth of each pixel in the screen space of each rendering, the corresponding point in the original world space can be computed. Appropriately connecting these points yields polygonal faces forming polygonal surface patches approximately covering some portion of the sweep volume. Each view frustum adds one or more surface patches in this way, and these presumably overlapped polygonal surface patches approximately enclose the whole sweep volume. These patches may further be processed to yield non-overlapped polygonal surfaces as an approximation to the boundary of the original 3D sweep volume.

• International Journal of CAD/CAM
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• v.9 no.1
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• pp.111-120
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• 2010

In this paper, we propose a volume rendering method using grid computing for large-scale volume data. Grid computing is attractive because medical institutions and research facilities often have a large number of idle computers. A large-scale volume data is divided into sub-volumes and the sub-volumes are rendered using grid computing. When using grid computing, different computers rarely have the same processor speeds. Thus the return order of results rarely matches the sending order. However order is vital when combining results to create a final image. Job-Scheduling is important in grid computing for volume rendering, so we use an obstacle-flag which changes priorities dynamically to manage sub-volume results. Obstacle-Flags manage visibility of each sub-volume when line of sight from the view point is obscured by other subvolumes. The proposed Dynamic Job-Scheduling based on visibility substantially increases efficiency. Our Dynamic Job-Scheduling method was implemented on our university's campus grid and we conducted comparative experiments, which showed that the proposed method provides significant improvements in efficiency for large-scale volume rendering.

• THE INTERNATIONAL COMMERCE & LAW REVIEW
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• v.27
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• pp.29-65
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• 2005

Northeast Asian economies have achieved high levels of growth due to a stable economic environments and economic policy reforms for free trade. As Northeast Asia has been risen as big bloc in the world and in the future in case free trade agreement could be concluded, trade volume could be increased dramatically. And it is evident that disputes will be increased in Northeast Asian economic bloc. Arbitration must be popular in resolving international commercial disputes in Northeast Asian bloc in order to increase the volume of intra-trade in the bloc. Through arbitration, the parties can have full autonomy and can resolve disputes independently, impartially and without delay. But in order for the parties to make use of arbitration in the bloc, they must be fully aware of the arbitration laws of Northeast Asian nations in view of the similarity and difference of the laws. Therefore, this paper deals with arbitral award in Northeast Asian Nations' arbitration laws in view of comparative law.

• Journal of the Korean School Mathematics Society
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• v.18 no.4
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• pp.371-385
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• 2015

In this paper we investigate the axioms defining area and volume so that revisit area formula for triangle, volume formula for triangular pyramid, and related contents in school mathematics from the view point of axiomatic method and Hilbert's third problem.

• Journal of the Korean Society of Clothing and Textiles
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• v.20 no.3
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• pp.438-451
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• 1996

This study was performed to provide basic data for design of maternity brassiere. In order to find out transformation of breast size, shape and volume properties during the period of pregnancy, direct measurements of 306 subjects using Martin's anthropometer and indirect measurements using photography were conducted. And also breast surface area, volume and assumed weight using the molding of adhisive sheet are calculated. The results are as follows; 1) Size (breast widths, depths, girths and lengths) of the breast of pregnant woman are gradually increased during pregnancy. But underbust girth is decreased after delivery. 2) Front view of the breast is gradully dropped and widened. 3) Surface area, volume were measured for each stage of pregnancy, and weights of breasts were estimated. The surface area of breast of latter stage of prgnancy was increased 1.7 times comparing with the early stage. 4) Changes of bust girth, breast depth, underbust girth, volume and estimated breast weight during pregnancy should be considered for cup size, cup shape, width and strain of strap, and width of the wings.

• The Journal of Korean Society for Radiation Therapy
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• v.32
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• pp.73-83
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• 2020

Purpose: The purpose of this study is to confirm the matching of the electron density between tissue and gas due to variation of abdominal gas volume in MRgART (Magnetic Resonance-guided Adaptive Radiation Therapy) for pancreatic cancer patients, and to confirm the effect on the dose change and treatment time. Materials and Methods: We compared the PTV and OAR doses of the initial plan and the AGC(Abdominal gas correction) plans to one pancreatic cancer patient who treated with MRgART using the ViewRay MRIdian System (Viewray, USA) at this clinic. In the 4fx AGC plans, Beam ON(%) according to the patient's motion error was checked to confirm the effect of abdominal gas volume on treatment time. Results: Comparing the Initial plan with the average value of AGC plan, the dose difference was -7 to 0.1% in OAR and decreased by 0.16% on average, and in PTV, the dose decreased by 4.5% to 5.5% and decreased by 5.1% on average. In Adaptive treatment, as the abdominal gas volume increased, the Beam ON(%) decreased. Conclusion: Abdominal gas volume variation causes dose change due to inaccurate electron density matching between tissue and gas. In addition, if the abdominal gas volume increases, the Beam ON(%) decreases, and the treatment time may increase due to the motion error of the patient. Therefore, in MRgART, it is necessary to check the electron density matching and minimize the variability of the abdominal gas.

• Clean Technology
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• v.14 no.4
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• pp.248-255
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• 2008

The volume expansion of three ionic liquids (ILs) in the presence of supercritical carbon dioxide has been measured at pressures up to 32 MPa and at temperatures from 313.15 to 333.15 K in a high-pressure view cell. The imidazolium-derivative ionic liquids 1-butyl-3-methylimidazolium hexafluorophosphate ([bmim][$PF_6$]), 1-butyl-3-methylimidazolium tetrafluoroborate ([bmim][$BF_4$]), and 1-octyl-3-methylimidazolium tetrafluoroborate ([omim][$BF_4$]) were employed in this research. The effects of pressure, temperature, nature of anion and cation as well as the water content on the volume expansion of ILs by absorbing $CO_2$ were investigated experimentally. The volume expansion was higher for the ILs with longer cationic alkyl group and for the ILs with lower anion polarity. The lower the water content, the lower the temperature, or the higher the pressure, the higher was the expansion of IL phase.

• Clean Technology
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• v.17 no.1
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• pp.19-24
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• 2011

The bubble point pressures of binary mixtures of carbon dioxide ($CO_2$) and N,N-dimethylformamide (DMF) were measured by using a high-pressure experimental apparatus equipped with a variable-volume view cell, at various $CO_2$ compositions in the range of temperatures above the critical temperature of $CO_2$ and below the critical temperature of DMF. The experimental bubble point pressure data were correlated with the Peng-Robinson equation of state (PR-EOS) to estimate the corresponding dew point compositions at equilibrium with the bubble point compositions. The experimentally measured bubble point pressures gave good agreement with those calculated by the PR-EOS. The variable-volume view cell equipment was verified to be an easy and quick way to measure the bubble point pressures of high-pressure compressible fluid mixtures.