• Proceedings of the Korean Magnestics Society Conference
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• 2009.12a
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• pp.204-205
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• 2009

The magnetic properties and structure of FeRh thin film pitaxially grown onto MgO(001) substrate were studied by MPMS(Magnetic Properties Measure System) and in-situ temperature synchrotron XRD(X-ray Diffraction). The transition temperature of FeRh thin films was around 380K. Both M-T curve and d-spacing changes correspond to each other very closely.

• Journal of the Korean Society of Visualization
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• v.2 no.1
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• pp.12-17
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• 2004

The physical characteristics of soot near the soot inception point were investigated with various measurements. In-situ measurements of particle size and volume fraction were introduced based on time resolved laser-induced incandescence (TIRE-LII) and laser-induced ion mobility (LIIM). The one has more convenience and accuracy than conventional LII technique and the other works best for particle sizes of a few nanometers at high concentrations in a uniform concentration field. A complementary ex-situ measurement of particle size is nano differential mobility analyzer (Nano-DMA), which recently developed for measuring particle sizes between 2nm and 100nm and provides high-resolution size information for early soot. Particles will be also collected on transmission electron microscope (TEM) grids using rapid thermophoretic sampling and analyzed for morphology. These measurements will allow fresh and original insight into the characterizing soot inception process. The measured physical properties of incipient soot will clarify the controlling growth mechanism combined with chemical ones, and the dominant mechanism for soot modeling can be deduced from the information.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.07a
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• pp.861-864
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• 2000

Ferroelectric thin film capacitors with high dielectric constant are important for the application of memory devices. In this work, thin films of PLT(28)(Pb$\sub$0.72/La$\sub$0.28/Ti$\sub$0.93/O$_3$) were fabricated on Pt/Ti/SiO$_2$/Si substrates in-situ annealing and ex-situ annealing have been compared depending on the annealing time. We have systematically investigated the variation of grain sizes depending on the condition of post-annealing and the variation of deposition rate. C-V measurement, ferroelectric properties, leakage current and SEM were performed to investigate the electrical properties and the microstructural properties of Pb(La,Ti)O$_3$.

• International Journal of Highway Engineering
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• v.17 no.6
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• pp.1-9
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• 2015

PURPOSES : The objective of this study is to propose a quality control and quality assurance method for use during asphalt pavement construction using non-destructive methods, such as ground penetrating radar (GPR) and an infrared (IR) camera. METHODS : A 1.0 GHz air-coupled GPR system was used to measure the thickness and in situ density of asphalt concrete overlay during the placement and compaction of the asphalt layer in two test construction sections. The in situ density of the asphalt layer was estimated based on the dielectric constant of the asphalt concrete, which was measured as the ratio of the amplitude of the surface reflection of the asphalt mat to that of a metal plate. In addition, an IR camera was used to monitor the surface temperature of the asphalt mat to ensure its uniformity, for both conventional asphalt concrete and fiber-reinforced asphalt (FRA) concrete. RESULTS : From the GPR test, the measured in situ air void of the asphalt concrete overlay gradually decreased from 12.6% at placement to 8.1% after five roller passes for conventional asphalt concrete, and from 10.7% to 5.9% for the FRA concrete. The thickness of the asphalt concrete overlay was reduced from 7.0 cm to 6.0 cm for the conventional material, and from 9.2 cm to 6.4 cm for the FRA concrete. From the IR camera measurements, the temperature differences in the asphalt mat ranged from $10^{\circ}C$ to $30^{\circ}C$ in the two test sections. CONCLUSIONS : During asphalt concrete construction, GPR and IR tests can be applicable for monitoring the changes in in situ density, thickness, and temperature differences of the overlay, which are the most important factors for quality control. For easier and more reliable quality control of asphalt overlay construction, it is better to use the thickness measurement from the GPR.

• Tunnel and Underground Space
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• v.17 no.2 s.67
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• pp.90-101
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• 2007

With increasing development of underground space, underground pumped storage power plants, which generate power by felling water in upper reservoir to lower reservoir, have been continuously constructed. For efficient and safe design, construction and maintenance or such power plants, it is very important to understand in-situ stress and the mechanical properties of the surrounding rock mass at the design stage. The power plant presented in this paper is under construction at a depth of $320{\sim}375m$. For stability evaluation of the structure, in-situ stress was measured by over-coring method. Also pressurementer test and a series or laboratory tests were performed to obtain the mechanical properties. Numerical analyses were conducted to check the efficiency of designed support patterns. The results showed that unstable areas occurred partly in the numerical model, and therefore supports were additionally applied. Finally complete stability was obtained and the following excavation has been operated successfully until now.

• Journal of Advanced Marine Engineering and Technology
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• v.39 no.10
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• pp.1011-1016
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• 2015

Gas piping systems in power plants and factories are always influenced by the mechanical vibrations of rotational machines such as pumps, blowers, and compressors. Unusual vibrations in a gas piping system influence possible leakages of liquids or gases, which can lead to large explosive accidents. Real-time measurements of unusual vibrations in piping systems in situ prohibit them from being possible leakages owing to the repeated fatigue of vibrations. In this paper, a non-contact 3-dimensional measurement system that can detect the vibrations of a solid body and monitor its vibrational modes is introduced. To detect the displacements of a body, a stereoscopic camera system is used, through which the major vibration types of solid bodies (such as X-axis-major, Y-axis-major, and Z-axis-major vibrations) can be monitored. In order to judge the vibration types, an artificial neural network is used. The measurement system consists of a host computer, stereoscopic camera system (two-camera system, high-speed high-resolution camera), and a measurement target. Through practical application on a flat plate, the measured data from the non-contact measurement system showed good agreement with those from the original vibration mode produced by an accelerator.

• Korean Journal of Remote Sensing
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• v.30 no.4
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• pp.455-464
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• 2014

After launching the Geostationary Ocean Color Imager (GOCI) on June 2010, field campaigns were performed routinely around Korean peninsula to collect in-situ data for calibration and validation. Key measurements in the campaigns are radiometric ones with field radiometers such as Analytical Spectral Devices FieldSpec3 or TriOS RAMSES. The field radiometers must be regularly calibrated. We, in the paper, introduce the optical laboratory built in KOSC and the relative calibration method for in-situ measurement spectroradiometer. The laboratory is equipped with a 20-inch integrating sphere (USS-2000S, LabSphere) in 98% uniformity, a reference spectrometer (MCPD9800, Photal) covering wavelengths from 360 nm to 1100 nm with 1.6 nm spectral resolution, and an optical table ($3600{\times}1500{\times}800mm^3$) having a flatness of ${\pm}0.1mm$. Under constant temperature and humidity maintainance in the room, the reference spectrometer and the in-situ measurement instrument are checked with the same light source in the same distance. From the test of FieldSpec3, we figured out a slight difference among in-situ instruments in blue band range, and also confirmed the sensor spectral performance was changed about 4.41% during 1 year. These results show that the regular calibrations are needed to maintain the field measurement accuracy and thus GOCI data reliability.

• Proceedings of the KIEE Conference
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• 2006.04a
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• pp.96-98
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• 2006

A new ex-situ model to diagnose a plasma processing equipment was presented. The model was constructed by combining wavelet, scanning electron microscope, ex-situ measurement of etching profile, and neural network. The diagnosis technique was applied to a tungsten etching process, conducted in a $SF_6$ helicon plasma. The wavelet was used to characterize detailed variations of plasma-etched surface. The diagnosis model was constructed with the vertical wavelet component. For comparison, a conventional model was built by using the estimated profile data. Compared to the conventional model, the wavelet-based model, demonstrated a much improved diagnosis.

• Tunnel and Underground Space
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• v.27 no.1
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• pp.26-38
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• 2017

In this study, bedding rock permeability was measured using Berea sandstones with three different beddings. The fracture permeability was also measured using tight sandstone with two different fracture regimes considering in-situ stress conditions. The Berea sandstone with vertical, horizontal and non-bedding was used to analyze evolution of permeability upon in-situ stress conditions. In order to describe applied effective stress around rock in underground, the triaxial pressure cell & hydrostatic pressure cell was designed and permeability experiments were performed with controlled axial and confining pressures. The measurement of permeability was conducted by increasing and decreasing effective stress. The permeability of non-bedding rock sample is the most sensitive to applied stress conditions and fracture permeability of tight sandstone increases with fracture treatment with proppant.

• Journal of Navigation and Port Research
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• v.26 no.5
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• pp.571-575
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• 2002

An immersion-type on-line refractometer useful for the in-situ measurement of salinity and temperature of sea water is developed, and its performance is examined by applying the refractometer to known salt solution having salt concentration between 2 and 4 % similar to practical sea water salinity. Since refractive index and temperature are measured simultaneously, it is possible to compensate the effect of temperature for fast and direct measurement. The outcome of salinity measurement for the different concentrations of salt solution indicates that the device is suitable for the salinity measurement by yielding stable and reproducible reading.