• Journal of Applied Reliability
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• v.16 no.1
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• pp.41-47
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• 2016

Purpose: The purpose of this study was to evaluate electrical and structural degradation of flexible CIGS sollar cell exposed to high temperature and humid atmosphere. Method: Accelerated degradation was performed for various time under $85^{\circ}C/85%RH$ and then electrical and structural properties were analyzed by 4-point probe method, scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and X-ray diffraction (XRD). Results: Sheet resistance of the top ITO layer increased with exposure time to the high temperature and humid atmosphere. Blunting of the protrusion morphology of ITO layer was observed for the degraded specimen, while no phase change was detected by XRD. Oxygen was detected at the edge area after 300 hours of exposure. Conclusion: Increase in electrical resistance of the degraded CIGS solar cell under high temperature and humid environment was attribute to the oxygen or water absorption.

• Journal of the Korea Institute of Building Construction
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• v.3 no.4
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• pp.129-134
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• 2003

The purpose of this study is to evaluate efficiency by the Life Cycle Cost(LCC) analysis of floor covering materials for remodeling. This study has been performed as a case study. The LCC analysis is a technique which takes account into both initial-future costs and benefits of an investment over some period of time. LCC is important in commercial decision making because it provides improved assessment of the living-term cost effectiveness of construction projects as well as alternative economic methods that focus on initial costs. For LCC analysis and comparison, the present value technique is used. The results of this study are summarized as follows; (1) A LCC analysis model of floor covering materials is suggested through a case study (2) As a result of LCC case study, the type of sheet is analysed more economical than that of tile in floor covering materials.

• Korean Journal of Remote Sensing
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• v.20 no.1
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• pp.39-46
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• 2004

The generalized Rayleigh-Gans (GRG) approximation is usually used to compute the scattering amplitudes of leaves smaller or comparable to a wavelength, while the physical optics (PO) approach with the resistive sheet approximation is commonly used for leaves larger or comparable to the wavelength. In this paper, the scattering amplitudes of an elliptical leaf are computed using those theoretical scattering models (GRG and PO) at different frequencies. The accuracies of the analytical models for microwave scattering from deciduous leaves are investigated by comparison with the precise estimation by the method of moment (MoM). It was found that both the PO approach and the GRG approximation can be used alternatively for computing the scattering matrices of natural deciduous leaves at P-, L-, C- and X-band frequencies.

• Journal of the Korean Society of Industry Convergence
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• v.25 no.2_1
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• pp.185-193
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• 2022

For grippers of industrial robots, parallel grippers and multi-function finger grippers are used. The former has the advantage of low cost but has the disadvantage of low precision, and the latter has the advantage of excellent precision but has the disadvantage of being expensive. In this paper, we developed a grip that can detects the various shapes of the object to be gripped on the gripper surface by using mesured pressure information frome Veloset Sheet sensor so that the gripper can be gripped without deforming the surface of the gripper. Also we did not only developed the array type gripper and 4 array type grippers (ATG), but also confirmed the usefulness of array type gripper developed in this study according to the 4 predefined evaluation criteria

• Journal of Chest Surgery
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• v.56 no.5
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• pp.367-370
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• 2023

Perivascular epithelioid cell tumors (PEComas) are very rare mesenchymal neoplasms, composed of histologically and immunohistochemically distinctive cells that form a sheet-like appearance around vessel lumens. Although most are benign, a malignant subset does exist, complicating clinical diagnostic efforts. Proper evaluation and management are thus essential for long-term patient survival. Herein, we present a rare case of a benign pulmonary PEComa that was diagnosed postoperatively in a 45-year-old woman.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.3
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• pp.190-198
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• 2020

For domestic urban railways, which have a 19.7% aging rate, a performance evaluation is necessary to establish capital improvement investment plans. The performance evaluation, which was recently enacted in the relevant law, points out the excessive time and effort for acquiring data and evaluation. This study developed a performance evaluation simulation prototype using a virtual reality (VR) method to use as training contents for railway performance evaluations. The practical use of the VR technique to reduce the working time under poor environment conditions was confirmed through a literature review. A survey and consultation were conducted for urban railway experts to determine the weight of the performance evaluation items and the facility breakdown structure. This information was utilized to develop performance evaluation sheets for simulation. Based on the evaluation sheet, a training content prototype that evaluates the performance of platform safety doors was developed using VR techniques with HTC VIVE equipment. VR simulation tests were conducted for six players, and the prototype was sufficiently advantageous for a visual confirmation of the facility information. The result is expected to be useful for engineers to understand the performance evaluation process efficiently before an actual performance evaluation of urban railway facilities.

• Journal of the Korea institute for structural maintenance and inspection
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• v.17 no.3
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• pp.1-9
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• 2013

This paper presents high-velocity impact analysis of two-way RC slabs, including steel fibers and strengthening with fiber reinforced polymer (FRP) sheets for evaluating impact resistance. The analysis uses the LS-DYNA program, which is advanced in impact analysis. The present analysis was performed similarly to the high-velocity impact tests conducted by VTT, the technical research center of Finland, to verify the analysis results. High-velocity impact loads were applied to $2100{\times}2100{\times}250$ mm size two-way RC slab specimens, using a non-deformable steel projectile of 47.5kg mass and 134.9m/s velocity. In this research, extra impact analysis of material specimens was carried out to verify the material models used to the analysis. The elastic-plastic hydrodynamic model, concrete damage model and orthotropic elastic model were used to simulate the non-linear softening behavior of steel fiber reinforced concrete (SFRC), and material properties of normal concrete and FRP sheets, respectively. It is concluded that the suggested analysis technique has good reliability, and can be effectively applied in evaluating the effectiveness of reinforcing/retrofitting materials and techniques. Also, the Steel fiber and FRP sheet strengthening systems provided outstanding performance under high-velocity impact loads.

• Korean Journal of Food Science and Technology
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• v.6 no.2
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• pp.65-69
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• 1974

Noodles were made from composite flours based on barley or sweet potato/wheat flour and their quality was assessed to obtain the following results. 1) In noodle sheet and dried noodle formation, barley flour could substitute 100% and sweet potato flour, 70% of wheat flour and their textural characteristics were improved by addition of glyceryl monostearate and sodium polycrylate. 2) Textural parameters such as hardness, cohesiveness and gumminess of noodle sheet and dried noodle were decreased by admixture of barley of sweet potato flour whereas they were increased by use of the additives. Noodle sheet required hardness over 6.2 and gumminess over 430 while dried noodle needed hardness over 6.8. 3) In cooked noodle, replacement of wheat flour and use of additives tended to lower the textural parameters. With respect to the cooking quality, barley flour could substitute 60% and sweet potato flour, 40% of wheat flour. 4) In organoleptic evaluation of cooked noodle with respect to its color, taste and texture, 20% replaced composite flour was not different significantly at 5% level from wheat flour and the quality defect was mainly due to discoloration of the product.

• Journal of the Korean Society of Radiology
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• v.13 no.7
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• pp.1015-1024
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• 2019

In the medical field, X-rays are essential in the diagnosis and treatment of diseases, and the use of X-rays continues to increase with the development of imaging technology, but X-rays have the disadvantage of radiation exposure. Although lead protection tools are used in clinical practice to protect against radiation exposure, lead is classified as a heavy metal and can cause harmful reactions such as lead poisoning. Therefore, the purpose of this study is to investigate the usefulness of the shield fabricated using materials of FDM (Fused Deposition Modeling) 3D printer. In order to confirm the filament's line attenuation factor, phantoms were fabricated using PLA, XT-CF20, Wood, Glow and Brass, and CT scan was performed. And the shielding sheet of 100 × 100 × 2 mm size was modeled, the dose and shielding rate was measured by using a diagnostic X-ray generator and irradiation dose meter, and the shielding rate with lead protection tools. As a result of the experiment, the CT number of the brass was measured to be the highest, and the shielding sheet was manufactured by using the brass. As a result of confirming with the diagnostic X-ray generator, the shielding rate was increased in the shielding sheet having a thickness of 6 mm upon X-ray irradiation under the condition of 100 kV and 40 mAs. It measured by 90% or more, and confirmed that the shielding rate is higher than apron 0.25 mmPb. As a result of this study, it was confirmed that the shield fabricated by 3D printing technology showed high shielding rate in the diagnostic X-ray region. there was.

• The Journal of Society for e-Business Studies
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• v.22 no.1
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• pp.1-13
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• 2017

Though digital imaging devices such as smart phones, digital cameras and office scanners have improved significantly over the past years, they are seldom used for industrial application. This may be attributable to high level of quality and performance requirement for industrial application, but there lacks a test or an objective evaluation whether the upgraded performance of entry-level device is sufficiently enough to replace existing industrial equipments or not. If there exists an industrial application area where the applicability of entry-level equipment is proved by some objective tests, then companies will be able to reduce investment on expensive industrial equipment. In this study, applicability of entry-level digital devices for color difference discrimination of PVC (Polyvinyl chloride) color sheet is tested. By testing smart phone, digital camera, and office scanner for color difference discrimination, authors have found that office scanner shows consistent result with less measurement error. Additional experiment on comparing office scanner with industrial spectrophotometer has confirmed that there exists high correlation between the two devices' results. Based on this result, office scanner may be applicable to discriminate the color difference of PVC sheet instead of expensive industrial spectrophotometer if proper management criteria are established.