Publications by authors named "Youn-Su Kim"

Software has become a vital factor in the fourth industrial revolution. Owing to the increase in demand for software products in various fields (big data, artificial intelligence, the Internet of Things, etc.), the software industry has expanded more than ever before.

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Article Synopsis
  • From November to December 2020, South Korea experienced a third wave of COVID-19, leading to increased social distancing measures in Seoul and a rise in daily confirmed cases.
  • The paper focuses on the significance of timing predictions rather than solely estimating the number of confirmed cases, analyzing data across five groups and subdividing them into 19 cases.
  • Utilizing the ARIMA model for forecasts, the study aims to provide insights that can help the Korean government and the KDCA implement effective measures to curb future outbreaks.
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We report a method for controlling the orientations of conjugated polymers in the active layer of organic thin-film transistors (OTFTs) by annealing the film at the melting temperature in a vertically aligned multiwalled carbon nanotube (VA-CNT) template under various load pressures. Poly(3-hexylthiophene) [P3HT] molecules are effectively aligned in the melting state annealing at 240 °C for 30 min, as a result of intermolecular π-π and CH3-π interactions between the polymer and the VA-CNTs, which are separated from the conjugated polymer film after cooling to room temperature. In-plane and out-of-plane X-ray diffraction results show that the melt-annealed P3HT film with VA-CNTs has better crystallite ordering than a pristine 80 °C baked film and a melt-annealed film without VA-CNTs, and a larger number of crystallites in the treated P3HT film are oriented in the [100] direction, which is normal to the substrate.

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This paper describes the fabrication and characterization of a hybrid nanostructure comprised of carbon nanotubes (CNTs) grown on graphene layers for supercapacitor applications. The entire nanostructure (CNTs and graphene) was fabricated via atmospheric pressure chemical vapor deposition (APCVD) and designed to minimize self-aggregation of the graphene and CNTs. Growth parameters of the CNTs were optimized by adjusting the gas flow rates of hydrogen and methane to control the simultaneous, competing reactions of carbon formation toward CNT growth and hydrogenation which suppresses CNT growth via hydrogen etching of carbon.

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We have one-pot fabricated Si-based nanocomposite electrodes containing Ag nano-dots for thin-film Li rechargeable batteries by a co-sputtering method. The structural and electrochemical properties of the Si/Ag nanocomposite electrodes are investigated via transmission electron microscopy (TEM), field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), and cycler. The TEM and XRD results show that crystalline Ag nano-dots (approximately 5-9 in size) are well-dispersed within an amorpohous Si matrix.

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A novel and effective methodology to control the diameters of semiconductor nanowires is reported through a versatile contact-printing method for obtaining size-controlled nanocatalysts by size-tunable carbon-based nanometer stamps. Vertically aligned carbon nanopost arrays, derived from nanoporous alumina templates, are used as the nanoscale stamps for printing of catalyst nanoparticles. The diameter of the carbon nanopost can be engineered by adjusting the pore dimension of the templates.

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We report a novel platform for intracellular delivery of genetic material and nanoparticles, based on vertically aligned carbon nanosyringe arrays (CNSAs) of controllable height. Using this technology, we have shown that plasmid and quantum dots can be efficiently delivered to the cytoplasm of cancer cells and human mesenchymal stem cells. The CNSA platform holds great promise for a myriad of applications including cell-based therapy, imaging, and tracking in vivo, and in biological studies aimed at understanding cellular function.

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We have synthesized supercapacitor electrodes fashioned of NiO(x)/multiwalled carbon nanotubes (MWNTs), in which the controlled NiO(x) nanoparticles were prepared via a simple colloidal method and supported on the MWNTs. The sizes of the NiO(x) nanoparticles on MWNTs were systematically varied from 4 to 14 nm at a fixed metal loading of 20 wt% by changing sintering temperature in a controlled manner. The maximum specific capacitance of the NiO(x)/MWNTs was measured to be ca.

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Patterned arrays of Fe oxide nanoparticles were transferred via contact printing method on a substrate surface using carbon nanotubes embedded in anodic aluminum oxide (CNTs/AAO) as a stamp, in which vertically aligned CNTs in hexagonally patterned array was first fabricated by chemical vapor deposition into the AAO, followed by a partial chemical etching to expose the CNTs from the AAO. Fe precursor inked CNTs stamp was contact-printed on a Pt-coated Si substrate, and after heat treatment at 200 degrees C, patterned array of Fe oxide nanoparticles with ca. 80 nm of diameter and ca.

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A new and simple method for the fabrication of densely packed magnetic nanodot arrays was developed using conventional sputtering deposition at room temperature. An anodized alumina template was employed for the formation of nanodot assemblies, consisting of carbon nanotubes (CNTs) and magnetic nanodot arrays. Each nanodot was formed exactly on top of a CNT and was arranged with a well-ordered structure in a wide range of area.

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A nanoscale tubular carbon structure array was demonstrated as a mold for nanoimprint lithography (NIL), in which a vertically formed and hexagonally aligned nanoscale tubular carbon array was fabricated through carbon growth inside an anodic aluminum oxide (AAO) nanotemplate, followed by controlled chemical etching of the AAO layer. High density (over 10(10) cm(-2)) of the nanoscale carbon pillars with their controlled diameters and protruded lengths was inversely replicated onto a UV-curable resist for the first time using the imprinting lithography technique.

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Tanshinone IIA is one of the most abundant constituents of the root of Salvia miltiorrhiza BUNGE which exerts antioxidant and anti-inflammatory actions in many experimental disease models. In the present study, we demonstrated that the standardized fraction of S. miltiorrhiza (Sm-SF) was able to protect RAW 264.

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We report electrochromic and electrochemical properties of a WO3-Ta2O5 nanocomposite electrode that was fabricated from co-sputtering. Transmission electron microscopy (TEM) images of the WO3-Ta20 nanocomposite electrode revealed that morphology of the WO3 film was changed by incorporation of Ta2O5 nanoparticles, and their chemical states were confirmed to be W6+ and Ta5+ oxides from X-ray photoelectron spectroscopy (XPS). The introduction of Ta2O5 to the WO3 film played a role in alleviating surface roughness increase during continuous potential cycling; whereas the surface roughness of the WO3 film was increased from ca.

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The relationship between the structural properties of Sn nano-dots embedded in a Si electrode synthesised by co-sputtering and their electrochemical performance during a lithium insertion and extraction process has been investigated.

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