• Proceedings of the KSR Conference
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• 2003.10c
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• pp.345-350
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• 2003

The inside of EMU is supplied with the cooling air from air-conditioner and the fresh air from exterior through the air-conditioner duct which is one of the air conditioning system. The shape of air-conditioner duct is a major factor in determining the air-conditioning efficiency, thermal comfort and energy efficiency. Therefore, this study is to understand the flow characteristics in the air-conditioner duct by three dimensional numerical simulation. The air-conditioner duct was calculated for the design volume flow rate, $2,726\;m^3/h/unit$. From the result of calculation and measurement, the velocity at diffuser outlet presented good agreement in general. [n this present study, the calculation was also performed for three volume flow rate(1,800, 2,200, 3,000 $m^3/h/unit$) and total pressure characteristic curve with volume flow rate was presented.

• The Bulletin of The Korean Astronomical Society
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• v.37 no.2
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• pp.234.2-234.2
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• 2012

As the accuracy in the measurement of cosmological parameters is ever-increasing in this era of precision cosmology, astrophysical constraints on high-redshift universe is also getting tighter. Three dimensional (3D) tomography of the high-redshift (z>~7) universe is expected to be made through the next-generation radio telescopes including various SKA pathfinders and SKA itself, which calls for extensive theoretical predictions. We present our new simulations of cosmic reionization covering the full dynamic range of radiation sources, and also the mock data for the (1) large-scale CMB polarization anisotropy for Planck mission, (2) small-scale, kinetic Sunyaev-Zel'dovich effect for South Pole Telescope project, and (3) 21-cm observations. We show that the new constraints on CMB from Planck will constrain the models of reionization significantly, which then should be tested by 3D tomography of high-redshift universe through the 21-cm observations by future radio telescopes.

• Proceedings of the Korea Institute of Convergence Signal Processing
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• 2003.06a
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• pp.110-113
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• 2003

In this paper, the multi-channel high speed data acquisition system is implemented. This high speed signal processing system for 3-D image display is applicable to the manipulation of a medical image processing, multimedia data and various fields of digital image processing. In order to convert the analog signal into digital one, A/D conversion circuit is designed. PCI interface method is designed and implemented, which is capable of transmission a large amount of data to computer. In order to, especially, channel extendibility of images acquisition, bus communication method is selected. By using this bus method, we can interface each module effectively. In this paper, 32-channel A/D conversion and PCI interface system for 3-dimensional and real-time display of the retina image is developed. The 32-channel image acquisition system and high speed data transmission system developed in this paper is applicable to not only medical image processing as 3-D representation of retina image but also various fields of industrial image processing in which the multi-point realtime image acquisition system is needed.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.3
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• pp.853-858
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• 2010

DRAM package substrate has been demonstrated using a thick alumina layer produced by aluminum anodization process. To apply a transmission-based design methodology, 2 dimensional electromagnetic simulation is performed. The design parameters including signal line width/spacing and alumina's thickness are optimized based on the simulation analysis and are verified with the fabrication and the measurement of the test patterns on the anodic alumina substrate. DDR2 DRAM package is chosen as a design vehicle. Aluminum anodization technique has been applied successfully to fabricate new DRAM package substrate.

• Archives of Metallurgy and Materials
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• v.66 no.3
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• pp.689-693
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• 2021

In this study, we propose a cooling structure manufactured using a specialized three-dimensional (3D) printing design method. A cooling performance test system with complex geometry that used a thermoelectric module was manufactured using metal 3D printing. A test model was constructed by applying additive manufacturing simulation and computational fluid analysis techniques, and the correlation between each element and cooling efficiency was examined. In this study, the evaluation was conducted using a thermoelectric module base cooling efficiency measurement system. The contents were compared and analyzed by predicting the manufacturing possibility and cooling efficiency, through additive manufacturing simulation and computational fluid analysis techniques, respectively.

• Radiation Oncology Journal
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• v.38 no.1
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• pp.60-67
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• 2020

Purpose: We performed three-dimensional (3D) dose reconstruction-based pretreatment verification to evaluate gamma analysis acceptance criteria in volumetric modulated arc therapy (VMAT) for prostate cancer. Materials and Methods: Pretreatment verification for 28 VMAT plans for prostate cancer was performed using the COMPASS system with a dolphin detector. The 3D reconstructed dose distribution of the treatment planning system calculation (TC) was compared with that of COMPASS independent calculation (CC) and COMPASS reconstruction from the dolphin detector measurement (CR). Gamma results (gamma failure rate and average gamma value [GFR and γAvg]) and dose-volume histogram (DVH) deviations, 98%, 2% and mean dose-volume difference (DD_98%, DD_2% and DD_mean), were evaluated. Gamma analyses were performed with two acceptance criteria, 2%/2 mm and 3%/3 mm. Results: The GFR in 2%/2 mm criteria were less than 8%, and those in 3%/3 mm criteria were less than 1% for all structures in comparisons between TC, CC, and CR. In the comparison between TC and CR, GFR and γAvg in 2%/2 mm criteria were significantly higher than those in 3%/3 mm criteria. The DVH deviations were within 2%, except for DD_mean (%) for rectum and bladder. Conclusions: The 3%/3 mm criteria were not strict enough to identify any discrepancies between planned and measured doses, and DVH deviations were less than 2% in most parameters. Therefore, gamma criteria of 2%/2 mm and DVH related parameters could be a useful tool for pretreatment verification for VMAT in prostate cancer.

• Investigative Magnetic Resonance Imaging
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• v.19 no.3
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• pp.162-167
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• 2015

Purpose: To evaluate the usefulness of quantitative analysis of the facial nerve using contrast-enhanced three-dimensional (CE 3D) fluid-attenuated inversion recovery-volume isotopic turbo spin echo acquisition (FLAIR-VISTA) for the diagnosis of Bell's palsy in pediatric patients. Materials and Methods: Twelve patients (24 nerves) with unilateral acute facial nerve palsy underwent MRI from March 2014 through March 2015. The unaffected sides were included as a control group. First, for quantitative analysis, the signal intensity (SI) and relative SI (RSI) for canalicular, labyrinthine, geniculate ganglion, tympanic, and mastoid segments of the facial nerve on CE 3D FLAIR images were measured using regions of interest (ROI). Second, CE 3D FLAIR and CE T1-SE images were analyzed to compare their diagnostic performance by visual assessment (VA). The sensitivity, specificity, and accuracy of RSI measurement and VA were compared. Results: The absolute SI of canalicular and mastoid segments and the sum of the five mean SI (total SI) were higher in the palsy group than in the control group, but with no significant differences. The RSI of the canalicular segment and the total SI were significantly correlated with the symptomatic side (P = 0.028 and 0.015). In 11/12 (91.6%) patients, the RSI of total SI resulted in accurate detection of the affected side. The sensitivity, specificity, and accuracy for detecting Bell's palsy were higher with RSI measurement than with VA of CE 3D FLAIR images, while those with VA of CE T1-SE images were higher than those with VA of CE 3D FLAIR images. Conclusion: Quantitative analysis of the facial nerve using CE 3D FLAIR imaging can be useful for increasing the diagnostic performance in children with Bell's palsy when difficult to diagnose using VA alone. With regard to VA, the diagnostic performance of CE T1-SE imaging is superior to that of CE 3D FLAIR imaging in children. Further studies including larger populations are necessary.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.732-737
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• 2005

Distal 3D Real Object Duplication System(RODS) consists of 3D Scanner and Solid Freeform Fabrication System(SFFS). It is a device to make three-dimensional objects directly from the drawing or the scanning data. In this research, we developed an office type SFFS based on Three Dimensional Printing Process and a industrial SFFS using Dual Laser. An office type SFFS applied sliding mode control with sliding perturbation observer(SMCSPO) algorithm for control of this system. And we measured process variables about droplet diameter measurement and powder bed formation etc. through experiments. Also, in order to develop more elaborate and speedy system for large objects than existing SLS process, this study applies a new Selective Multi-Laser Sintering(SMLS) process and 3-axis dynamic Focusing Scanner for scanning large area instead of the existing $f\theta$ lens. In this process, the temperature has a great influence on sintering of the polymer. Also the laser parameters are considered like that laser beam power, scan speed, scan spacing. Now, this study is in progress to eveluate the effect of experimental parameters on the sintering process.

• Journal of KIISE:Software and Applications
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• v.31 no.7
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• pp.922-928
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• 2004

We propose a new 3 dimensional labeling method based on slice information for the volume data. This method is named SIL (Slice Information based Labeling). Compare to the conventional algorithms, it has advantages that the use of memory is efficient and it Is possible to combine with a variety of 2 dimensional labeling algorithms for finding an appropriate labeling algorithm to its application. In this study, we applied SIL to confocal microscopy images of cervix cancer cell and compared the results of labeling. According to the measurement, we found that the speed of Sd combined with, CCCL (Contour based Connected Component Labeling) is almost 2 times higher than that of other methods. In conclusion, considering that the performance of labeling depends on a kind of image, we obtained that the proposed method provide better result for the confocal microscopy cell volume data.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37B no.10
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• pp.912-920
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• 2012

In this paper, we derived a closed-form equation of a Best Linear Unbiased Estimator (BLUE) estimator for the 3 dimensional estimation of the position of the emitter based on the Time Difference of Arrival (TDOA) technique. The BLUE derived for the case of estimating 3 dimensional position of the emitter with 4 base stations or sensors, and for this purpose, we used an approximated equation of the TDOA hyperbola equation obtained from the first order Taylor-series after setting the reference points of the position. The derived equation can be used for any kind of noises which are uncorrelated in each other in the TOA measurement noises and for a white Gaussian noise also.