• Journal of Sensor Science and Technology
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• v.15 no.2
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• pp.120-126
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• 2006

Physicochemical and electrical properties for hydrogen gas sensors based on Pd-deposited $WO_3$ thin films were investigated as a function of Pd thickness, annealing temperature, and operating temperature. $WO_3$ thin films were deposited on an insulating material by thermal evaporator. XRD, FE-SEM, AFM, and XPS were used to evaluate the crystal structure, microstructure, surface roughness, and chemical property, respectively. The deposited films were grown $WO_3$ polycrystalline with rhombohedral structure after annealing at $500^{\circ}C$. The addition effect of Pd is not the crystallinity but the suppression of grain growth of $WO_3$. Pd was scattered an isolated small spherical grain on $WO_3$ thin film after annealing at $500^{\circ}C$ and it was agglomerated as an irregular large grain or diffused into $WO_3$ after annealing at $600^{\circ}C$. 2 nm Pd-deposited $WO_3$ thin films operated at $250^{\circ}C$ showed good response and recovery property.

• Journal of the Korean Society for Nondestructive Testing
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• v.36 no.4
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• pp.259-265
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• 2016

This paper presents a study on the use of pulsed phase thermography in the measurement of thermal barrier coating thickness with a numerical simulation. A multilayer heat transfer model was ussed to analyze the surface temperature response acquired from one-sided pulsed thermal imaging. The test sample comprised four layers: the metal substrate, bond coat, thermally grown oxide and the top coat. The finite element software, ANSYS, was used to model and predict the temperature distribution in the test sample under an imposed heat flux on the exterior of the TBC. The phase image was computed with the use of the software MATLAB and Thermofit Pro using a Fourier transform. The relationship between the coating thickness and the corresponding phase angle was then established with the coating thickness being expressed as a function of the phase angle. The method is successfully applied to measure the coating thickness that varied from 0.25 mm to 1.5 mm.

• Advances in aircraft and spacecraft science
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• v.4 no.5
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• pp.585-611
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• 2017

This article covenants with the post buckling witticism of carbon nanotube reinforced composite (CNTRC) beam supported with an elastic foundation in thermal atmospheres with arbitrary assumed random system properties. The arbitrary assumed random system properties are be modeled as uncorrelated Gaussian random input variables. Unvaryingly distributed (UD) and functionally graded (FG) distributions of the carbon nanotube are deliberated. The material belongings of CNTRC beam are presumed to be graded in the beam depth way and appraised through a micromechanical exemplary. The basic equations of a CNTRC beam are imitative constructed on a higher order shear deformation beam (HSDT) theory with von-Karman type nonlinearity. The beam is supported by two parameters Pasternak elastic foundation with Winkler cubic nonlinearity. The thermal dominance is involved in the material properties of CNTRC beam is foreseen to be temperature dependent (TD). The first and second order perturbation method (SOPT) and Monte Carlo sampling (MCS) by way of CO nonlinear finite element method (FEM) through direct iterative way are offered to observe the mean, coefficient of variation (COV) and probability distribution function (PDF) of critical post buckling load. Archetypal outcomes are presented for the volume fraction of CNTRC, slenderness ratios, boundary conditions, underpinning parameters, amplitude ratios, temperature reliant and sovereign random material properties with arbitrary system properties. The present defined tactic is corroborated with the results available in the literature and by employing MCS.

• 제어로봇시스템학회:학술대회논문집
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• 1999.10a
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• pp.278-280
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• 1999

This paper proposes controlling of temperature in an oven by using 4 bits Integral - Cycle Binary Rate Modulation (IBRM) method and ac line with frequency 50 Hz. Microcontroller MCS-51 controls IBRM according to Proportional Integral controller (PI) function. Discrete signals are used in the system modeled by using Ziegler Nichols principle for analyzing the stability before designing the system. This procedure makes it easy to investigate system response. The system is implemented by 4 bits digital circuit which gives 320 patterns of ac signal fur controlling the generation of energy for 3,000 watts thermal coil every 20 ms of each cycle. We divide scan time (Ts$\sub$n/) in to 20 intervals, 1 ms interval is selected to generate 16 patterns IBRM. Because of this method gives the ripple lower than 2% it generates less noise fur system. Moreover, we can consider whole system from the time model of control procedure and IBRM algorithm at 40-200$^{\circ}C$ with ${\pm}$ 1$^{\circ}C$ error in the 1 cubic meter oven.

• Journal of Software Engineering Society
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• v.27 no.1
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• pp.15-17
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• 2018

Fast response to livestock disease and raising the reproductive success rate contribute to the improvement of farm productivity and profit margins. Due to the decrease in farm workforce and aging population, efficient livestock healthcare and breeding management are needed. In this study, we developed a mobile application for livestock healthcare and breeding management based on the collected body temperature data by IoT sensors. In case of livestock health problem, users are notified immediately via a mobile application warning message. It also provides users with a livestock breeding date function, allowing them to respond without missing the breeding season.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.2299-2300
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• 2008

The Velocity Autocorrelation Function (VAF) of the sodium ions is calculated for a range of temperature from 250K to 1000K and converted into the linear ac-conductivity and ac-susceptibility response via Fourier transformation. A peak is found in the conductivity around $6{\times}10^{12}$ Hz that has some of the character of a Poley absorption. Here it is shown to be due to an harmonically coupled site vibrations of the sodium atoms, which extend only over a limited range. At frequencies below the peak the conductivity tends towards a constant i.e. dc value corresponding to a constant flow of ions through the simulation cell. At high temperatures the conductivity due to this ion transport process behaves like a metal with an insulator to metal transition occurring around a specific temperature.

• The Journal of Korean Physical Therapy
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• v.22 no.6
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• pp.71-76
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• 2010

Purpose: The purpose of this study was to examine changes in autonomic nerve responses after low-frequency transcutaneous electrical nerve stimulation (TENS). Methods: Research subjects were 24 students who attend University. Subjects were divided into two groups: 1 = a low intensity group; 2 = a high intensity group. Electrodes were attached to the forearm of the dominant arm and electrical stimuli were administered for 15 minutes. Outcome measures were skin conduction velocity, skin temperature, blood flow, and pulse frequency, each of which was measured a total of 4 times. The data were analyzed using a repeated measures ANOVA. Results: In changes in conduction velocity, the main effect of time variation (in black) was statistically significant. The interaction between time and group main effects was not statistically significant; nor was the difference between the groups. Results showed that skin conduction velocity changed without any relation to group. Conclusions: Low frequency TENS selectively increases skin conduction velocity, which may be helpful for activating sudomotor function regardless of intensity.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.06a
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• pp.379-380
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• 2008

Molecular Dynamics (MD) simulations have been used to model the dynamics of the charge-compensating sodium ions in the non-stoichiometric hollandite Nax$(Ti_{8-x}Cr_x)O_{16}$. These interstitial ions reside in 'tunnels' in the crystal structure and move under the forces of both the ions making up the cage structure and the many body interactions of the other sodium ions in the tunnel. The Velocity Autocorrelation Function (VAF) of the sodium ions is calculated for a range of temperature from 250K to 1000K and converted into the linear ac-conductivity and ac-susceptibility response via Fourier transformation. A peak is found in the conductivity around $6\times10^{12}$ Hz that has some of the character of a Poley absorption. Here it is shown to be due to an harmonically coupled site vibrations of the sodium atoms, which extend only over a limited range. At frequencies below the peak the conductivity tends towards a constant i.e. dc value corresponding to a constant flow of ions through the simulation cell. At high temperatures the conductivity due to this ion transport process behaves like a metal with an insulator to metal transition occurring around a specific temperature.

• Journal of The Institute of Information and Telecommunication Facilities Engineering
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• v.8 no.2
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• pp.90-95
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• 2009

All-optical fiber-type gain flattening filer (GFF) for an EDFA (Erbium doped fiber amplifier) were fabricated by using a FBT (fiber biconical tapered) process and the performance of the GFF was tested and athermal package was proposed. Historically, the chief contributor to gain unevenness has been the EDFA. Due to the inherent gain response of the EDFA's operation, there is always a modest imbalance in the gain applied as a function of wavelength. FBT methods have been used to make fiber type couplers and WDM filter since 1980. Attractivity of this methods was simple, cost effective and thermal stability. Simulation program tool is made to design target GFF profile for this paper. Fiber coupler manufacturing machine is modified for the GFF process. The final GFF is obtained by cascading 4 unit filter that has 6 taper stage. Test result shows 1 dB of wavelength flatness in the C band. Polarization dependent loss is under 0.15dB. The center wavelength variation is below ${\pm}$0.35nm at the temperature range of $20^{\circ}C$ to $70^{\circ}C$.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.12 no.4
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• pp.6-13
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• 1998

It is difficult to control for the level of the steam generator in the nuclear power plant because there is swell and shrink, and many disturbance such as, feed water rate, feedwater temperature, main steam flow rte, coolant temperature effect steam generator level. If the conventional PI controller use in this system, we cannot have a stability in the control of the lower power, the rejection function of disturbance, and the load following effectively. In this paper, e study the application of the of neural network based Kp, Ti for Pi controller to the level control of the steam generator of nuclear power plant through the simulation and experimental on the steam generator. We are satisfied with the resulting against the inturrupt of the disturbance, the change of setpoint through the simulation and the swell and shrink, the response of controller on the experimental steam generator.