• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.21 no.6
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• pp.855-859
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• 2012

Silicon nanowires (SiNWs) were fabricated by a metal-assisted chemical etching of Si and the porous structure on their surfaces was controlled by changing the volume ratio of the etching solution composed of hydrofluoric acid, hydrogen peroxide, and deionized water. The concentration of hydrogen peroxide as the oxidant was varied for controlling the porosity of SiNWs. The optical properties of porous SiNWs were unique and very different from those of single-crystalline Si, as characterized by measuring their photoluminescence and Raman spectra for different porosities.

• Journal of Korean Society on Water Environment
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• v.22 no.6
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• pp.1088-1093
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• 2006

In this study, the method of annual sediment estimation for reservoir long-term operation is proposed. Long-term daily precipitation and evaporation are predicted by Markov Chain. Using these values, reservoir inflow is simulated by NWS-PC model. Reservoir sediment load is estimated by sediment rating relation curve which is observed. From the simulation results, it was found that each simulated value by Markov Chain and NWS-PC was well compared to the observed ones and also estimated reservoir sediment was appropriate to the compared values using empirical equations. It is thought that the proposed method for estimation of reservoir sediment can be useful used to operate the reservoir.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.04b
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• pp.25-26
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• 2009

We design and demonstrate the controlled morphologies of Ag-dpped ZnO nanowires (NWs) adopting self-contrived hot-walled pulsed laser deposition (HW-PLD). p-type Ag-doping is ensuired by low temperature photoluminescence (PL) spectrum to find the AoX peak at 3.349 eV. Morphology of grown NWs are controlled by changing the kinetic energy and flux of the ablated particles with adjusting the target - substrate (T-S) distance. The analysis on the resultant NWs is presented.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.4B
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• pp.383-392
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• 2008

It is not always easy to estimate the parameters in hydrologic models due to insufficient hydrologic data when hydraulic structures are designed or water resources plan are established. Therefore, uncertainty analysis are inevitably needed to examine reliability for the estimated results. With regard to this point, this study applies a Bayesian Markov Chain Monte Carlo scheme to the NWS-PC rainfall-runoff model that has been widely used, and a case study is performed in Soyang Dam watershed in Korea. The NWS-PC model is calibrated against observed daily runoff, and thirteen parameters in the model are optimized as well as posterior distributions associated with each parameter are derived. The Bayesian Markov Chain Monte Carlo shows a improved result in terms of statistical performance measures and graphical examination. The patterns of runoff can be influenced by various factors and the Bayesian approaches are capable of translating the uncertainties into parameter uncertainties. One could provide against an unexpected runoff event by utilizing information driven by Bayesian methods. Therefore, the rainfall-runoff analysis coupled with the uncertainty analysis can give us an insight in evaluating flood risk and dam size in a reasonable way.

• Applied Science and Convergence Technology
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• v.27 no.1
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• pp.5-8
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• 2018

In this paper, plasma treatment effects on a ploy(dimethyl siloxane) substrate were analyzed for the applications of stretchable silver nanowire (Ag NWs) electrodes. The oxygen plasma treated sample shows the best performance compared to nitrogen treated and untreated samples. The lowest sheet resistance and reasonable stretching capability was achieved up to 20% strain condition without open circuit fail for the oxygen plasma treated sample.

• Korean Journal of Materials Research
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• v.25 no.3
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• pp.125-131
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• 2015

Fluorine-doped $SnO_2$ (FTO) thin film/Ag nanowire (NW) double layers were fabricated by means of spin coating and ultrasonic spray pyrolysis. To investigate the optimum thickness of the FTO thin films when used as protection layer for Ag NWs, the deposition time of the ultrasonic spray pyrolysis process was varied at 0, 1, 3, 5, or 10 min. The structural, chemical, morphological, electrical, and optical properties of the double layers were examined using X-ray diffraction, X-ray photoelectron spectroscopy, field-emission scanning electron microscopy, transmission electron microscopy, the Hall effect measurement system, and UV-Vis spectrophotometry. Although pure Ag NWs formed isolated droplet-shaped Ag particles at an annealing temperature of $300^{\circ}C$, Ag NWs covered by FTO thin films maintained their high-aspect-ratio morphology. As the deposition time of the FTO thin films increased, the electrical and optical properties of the double layers degraded gradually. Therefore, the double layer fabricated with FTO thin films deposited for 1 min exhibited superb sheet resistance (${\sim}14.9{\Omega}/{\Box}$), high optical transmittance (~88.6 %), the best FOM (${\sim}19.9{\times}10^{-3}{\Omega}^{-1}$), and excellent thermal stability at an annealing temperature of $300^{\circ}C$ owing to the good morphology maintenance of the Ag NWs covered by FTO thin films.

• Korean Journal of Materials Research
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• v.29 no.2
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• pp.87-91
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• 2019

We report on stretchable electrochromic films of poly(3-hexylthiophene) (P3HT) fabricated on silver nanowire (AgNW) electrodes. AgNWs electrodes are prepared on polydimethylsiloxane (PDMS) substrates using a spray coater for stretchable electrochromic applications. On top of the AgNW electrode, poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) is introduced to ensure a stable resistance over the electrode under broad strain range by effectively suppressing the protrusion of AgNWs from PDMS. This bilayer electrode exhibits a high performance as a stretchable substrate in terms of sheet resistance increment by a factor of 1.6, tensile strain change to 40 %, and stretching cycles to 100 cycles. Furthermore, P3HT film spin-coated on the bilayer electrode shows a stable electrochromic coloration within an applied voltage, with a color contrast of 28.6 %, response time of 4-5 sec, and a coloration efficiency of $91.0cm^2/C$. These findings indicate that AgNWs/PEDOT:PSS bilayer on PDMS substrate electrode is highly suitable for transparent and stretchable electrochromic devices.

• Korean Journal of Applied Biomechanics
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• v.16 no.2
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• pp.193-205
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• 2006

This study was to analysis the kinematic and kinetic differences between new walking shoe(NWS : RYN) and general walking shoe(GWS). The subjects for this study were 10 male adults who had the walking pattern of rearfoot shrike with normal foot. The movement of one lower leg was measured using plantar pressure and Vicon Motion Analysis Program(6 MX13 and 2 MX40 cameras : 100 f / s) while the subjects walked at the velocity(1.5m/s. on 2m).. The results of this study was as follows : 1. The NWS was better than the GWS that caused injuries such as adduction, abduction and pronation are reduced While walking on a perpendicular surface, the landing angle and the knees angles were extensive which makes walking more safe which reduces anxiety and uneasiness. 2. The bottom of the NWS were now made into a more circular arch which supports the weight of the body and reduces the irregular angles when wearing GWS. This arch made the supporting area more wide which made the upholding the trunk of the body more effective. The whole bottom of the foot that supports the weight is more flexible in addition, increases the safeness of walking patterns and the momentum of the body. 3. The moment the heel of the foot of the NWS touch the ground, the range of the pressure were partially notable and the range of the pressure on the upper part of the thigh were dispersed The injuries that occurred while walking. primary factors when a shock related injuries are reduced Judgements of the impacts of the knees and the spinal column dispersing could be made.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.215-216
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• 2013

The silicide is a compound of Si with an electropositive component. Silicides are commonly used in silicon-based microelectronics to reduce resistivity of gate and local interconnect metallization. The popular silicide candidates, CoSi2 and TiSi2, have some limitations. TiSi2 showed line width dependent sheet resistance and has difficulty in transformation of the C49 phase to the low resistive C54. CoSi2 consumes more Si than TiSi2. Nickel silicide is a promising material to substitute for those silicide materials providing several advantages; low resistivity, lower Si consumption and lower formation temperature. Nickel silicide (NiSi) nanowire (NW) has features of a geometrically tiny size in terms of diameter and significantly long directional length, with an excellent electrical conductivity. According to these advantages, NiSi NWs have been applied to various nanoscale applications, such as interconnects [1,2], field emitters [3], and functional microscopy tips [4]. Beside its tiny geometric feature, NW can provide a large surface area at a fixed volume. This makes the material viable for photovoltaic architecture, allowing it to be used to enhance the light-active region [5]. Additionally, a recent report has suggested that an effective antireflection coating-layer can be made with by NiSi NW arrays [6]. A unique growth mechanism of nickel silicide (NiSi) nanowires (NWs) was thermodynamically investigated. The reaction between Ni and Si primarily determines NiSi phases according to the deposition condition. Optimum growth conditions were found at $375^{\circ}C$ leading long and high-density NiSi NWs. The ignition of NiSi NWs is determined by the grain size due to the nucleation limited silicide reaction. A successive Ni diffusion through a silicide layer was traced from a NW grown sample. Otherwise Ni-rich or Si-rich phase induces a film type growth. This work demonstrates specific existence of NiSi NW growth [7].

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.29 no.6
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• pp.245-250
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• 2019

We investigated the post-annealing effect of Sn-incorporated β-Ga₂O₃ (β-Ga₂O₃ : Sn) nanowires (NWs) grown on sapphire (0001) substrates using radio-frequency powder sputtering. The β-Ga₂O₃ : Sn NWs were converted to a porous structure during the vacuum annealing process at 800℃. Host non-stoichiometric Ga₂O_3-x, is transformed into stoichiometric Ga₂O₃, where Sn atoms separate and form Sn nano-clusters that gradually evaporate in a vacuum atmosphere. As a result, the amount of Sn atoms was reduced from 1.31 to 0.27 at%. Pores formed on the sides of β-Ga₂O₃ : Sn NWs were observed. This increases the ratio of the surface to the volume of β-Ga₂O₃ : Sn NWs.