• Korean Journal of Heritage: History & Science
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• v.48 no.4
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• pp.4-23
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• 2015

Buried bronze objects are naturally corroded by their surrounding environment, which results in producing corrosion layers containing a number of constituents. Corrosion layers in stable condition protect the objects from the environment and also could provide information in terms of the objects. Characteristic and mechanism of the corrosion layers is likely to be valuable information for the conservation treatment. Many research have been conducted to figure out the formation and characteristic of the corrosion layers, but the more research should be conducted with various approach and analytical methods. Raman spectroscopy is one of the analytical methods to identify microcrystal as a compound while other analytical methods are used to identify element. Therefore, the aim of this research is to identify the characteristic of corrosion layers of both excavated bronze objects through the raman spectroscopy. Two analytical methods, which are raman spectroscopy and SEM~EDS, were used to analyse four excavated bronze bowls. In the case of bronze bowls, malachite was found from the exterior corrosion layer and albite, quartz, and microcline, which are minerals, were also found. Cuprite was detected from the interior corrosion layers illustrating slightly different spectrum due to the combined compound. Lead segregation shows the form of PbO, $PbSO_4$ and $PbCO_3$ or it replaced as cuprite. In this study, small number of samples were analysed. This research is likely to be useful information to figure out not only the characteristic of the corrosion layers but also the authenticity of the artifacts if relevant research will be conducted. Therefore, further comprehensive researches on the various archaeological objects and corrosion environment condition are required in the future.

• The KIPS Transactions:PartB
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• v.13B no.1 s.104
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• pp.15-20
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• 2006

This paper describes research on intelligent game character through performance enhancements of physics engine in computer games. The algorithm that recognizes the physics situation uses momentum back-propagation neural networks. Also, we present an experiment and its results, integration methods that display optimum performance based on the physics situation. In this experiment on integration methods, the Euler method was shown to produce the best results in terms of fps in a simulation environment with collision detection. Simulation with collision detection was shown similar fps for all three methods and the Runge-kutta method was shown the greatest accuracy. In the experiment on physics situation recognition, a physics situation recognition algorithm where the number of input layers (number of physical parameters) and output layers (destruction value for the master car) is fixed has shown the best performance when the number of hidden layers is 3 and the learning count number is 30,000. Since we tested with rigid bodies only, we are currently studying efficient physics situation recognition for soft body objects.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.32A no.3
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• pp.89-99
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• 1995

In this paper, we ecamined the effect that MCM-L technique influencess on the design and fabrication of multichip memory modules in increasing the packing desity of memory capacity and maximizing its electrical characteristics. For that purpose, we examined the effective methods of reducing the area of module layout and the wiring length with the variation of chip allocation and the number of wiring layers. We fabricated a 256K${\times}$8bit SRAM module with eight 32K${\times}$8bit SRAM chips. The routing experiment showed that we could optimize the area of module layout and wiring length by placing chips in a row, arranging module I/O pads parallel to chip I/O pads, and equalizing the number of terminal sides of module I/O's to that of chip I/O's. The routing was optimized when we used three wire layers in case of one sided chip mounting or five wire layers in case of double sided chip mounting. The fabricated modules showed 18.9 cm/cm$^{2}$ in wiring density, 65 % in substrate occupancy efficiency, and module substrate and functionally tested to find out the module working perfectly.

• Korean Journal of Microbiology
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• v.12 no.4
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• pp.153-158
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• 1974

Around and in the area of Wolgot-Muon, Gimpo-Gun, Kyunggi province, I examined total bacteria, general Pseudomonas spp., fluorescent Pseudomonas spp., in soil layers and also in different kinds of soil of respective diseased, uncultivated, and healthy areas, and found the followings. 1. In the diseased and uncultivated areas, the content of moisture and silt was greater than in the healthy area. 2. Contrary to the above, the healthy area contained a greater amount of inorganic elements such as $P_2O_5$, K, Ca and of soil particle such as Cs and Fs. The degree of pH and content of Mg were even in three types of soils. 3. Total bacteria were found in abundance in the healthy soil. It was observed that in all types of areas, bacteria reside in abundance in the rhizosphere, i.e., 10-15 cm layers and that the closer the surface, the greater the numbers of the bacteria. 4. General Pseudomonas spp. were also found to the greater in number on the surface of the soil, especially so in the rhizosphere, with the numbers decreasing as the soil layers increase. Numbers of this bacteria in all types of area were nearly uniform. 5. A great number of fluorescent Pseudomonas spp. were found in the diseased area, especially so in the rhizosphere.

• International Journal of Computer Science & Network Security
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• v.21 no.9
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• pp.203-211
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• 2021

Image tampering detection and localization have become an active area of research in the field of digital image forensics in recent times. This is due to the widespread of malicious image tampering. This study presents a new method for image tampering detection and localization that combines the advantages of dilated convolution, residual network, and UNET Architecture. Using the UNET architecture as a backbone, we built the proposed network from two kinds of residual units, one for the encoder path and the other for the decoder path. The residual units help to speed up the training process and facilitate information propagation between the lower layers and the higher layers which are often difficult to train. To capture global image tampering artifacts and reduce the computational burden of the proposed method, we enlarge the receptive field size of the convolutional kernels by adopting dilated convolutions in the residual units used in building the proposed network. In contrast to existing deep learning methods, having a large number of layers, many network parameters, and often difficult to train, the proposed method can achieve excellent performance with a fewer number of parameters and less computational cost. To test the performance of the proposed method, we evaluate its performance in the context of four benchmark image forensics datasets. Experimental results show that the proposed method outperforms existing methods and could be potentially used to enhance image tampering detection and localization.

• Bulletin of the Korean Chemical Society
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• v.23 no.3
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• pp.395-399
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• 2002

The voltammetric behavior of spontaneously adsorbing Mo layers on Pt(111) and Pt(100) electrodes has been studied to estimate the number of electrons involved in the electrochemical processes of spontaneously adsorbed Mo and the number of the bloc ked Pt sites for hydrogen adsorption. On Pt(111) and Pt(100) surfaces, the spontaneously adsorbed Mo layers showed redox peaks at 0.10 V and 0.15 V, respectively, and continuous current-potential waves in the conventional hydrogen region. Since the potential range of the Mo redox processes on both surfaces overlapped partially with the potential range of hydrogen adsorption, the variation in the ratio of the total charge of Mo and H ($Q_H$ +$Q_{MO}$) to the hydrogen charge of clean Pt electrode ($Q_H^0$) was analyzed. From the analysis, six electrons were estimated to be involved in the electrochemical processes of the spontaneously adsorbed Mo, and four Pt sites for hydrogen adsorption were calculated to be blocked by one adsorbed Mo atom. Based on these figures and the pH dependence of the Mo redox processes, we have proposed an electrochemical equation for the spontaneously adsorbed Mo. This electrochemical equation led us to conclude that the saturation coverage of the spontaneously adsorbed Mo is 0.25. The coverage of Mo less than 0.25, however, could not be determined voltammetrically due to the convolution of the charges of Mo and H.

• Journal of Multimedia Information System
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• v.8 no.2
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• pp.101-110
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• 2021

In computer vision, single-image super resolution has been an area of research for a significant period. Traditional techniques involve interpolation-based methods such as Nearest-neighbor, Bilinear, and Bicubic for image restoration. Although implementations of convolutional neural networks have provided outstanding results in recent years, efficiency and single model multi-scalability have been its challenges. Furthermore, previous works haven't placed enough emphasis on real-number scalability. Interpolation-based techniques, however, have no limit in terms of scalability as they are able to upscale images to any desired size. In this paper, we propose a convolutional neural network possessing the advantages of the interpolation-based techniques, which is also efficient, deeming it suitable in practical implementations. It consists of convolutional layers applied on the low-resolution space, post-up-sampling along the end hidden layers, and additional layers on high-resolution space. Up-sampling is applied on a multiple channeled feature map via bicubic interpolation using a single model. Experiments on architectural structure, layer reduction, and real-number scale training are executed with results proving efficient amongst multi-scale learning (including scale multi-path-learning) based models.

• JSTS:Journal of Semiconductor Technology and Science
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• v.6 no.3
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• pp.199-205
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• 2006

Patterned sapphire substrates (PSS) were fabricated by a simple wet etching process with $SiO_2$ stripe masks and a mixed solution of $H_2SO_4$ and $H_3PO_4$. GaN layers were epitaxially grown on the PSS under the optimized 2-step growth condition of metalorganic vapor deposition. During the 1st growth step, GaN layers with triangular cross sections were grown on the selected area of the surface of the PSS, and in the 2nd growth step, the GaN layers were laterally grown and coalesced with neighboring GaN layers. The density of threading dislocations on the surface of the coalesced GaN layer was $2{\sim}4\;{\times}\;10^7\;cm^{-2}$ over the entire region. The epitaxial structure of near-UV light emitting diode (LED) was grown over the GaN layers on the PSS. The internal quantum efficiency and the extraction efficiency of the LED structure grown on the PSS were remarkably increased when compared to the conventional LED structure grown on the flat sapphire substrate. The reduction in TD density and the decrease in the number of times of total internal reflections of the light flux are mainly attributed due to high level of scattering on the PSS.

• Korean Journal of Materials Research
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• v.28 no.2
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• pp.124-128
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• 2018

N-type porous silicon (PS) layers and thermally oxidized PS layers have been characterized by various measuring techniques such as photoluminescence (PL), Raman spectroscopy, IR, HRSEM and transmittance measurements. The top surface of PS layer shows a stronger photoluminescence peak than its bottom part, and this is ascribed to the difference in number of fine silicon particles of 2~3 nm in diameter. Observed characteristics of PL spectra are explained in terms of microstructures in the n-type PS layers. Common features for both p-type and n-type PS layers are as follows: the parts which can emit visible photoluminescence are not amorphous, but crystalline, and such parts are composed of nanocrystallites of several nm's whose orientations are slightly different from Si substrate, and such fine silicon particles absorb much hydrogen atoms near the surfaces. Light emission is strongly dependent on such fine silicon particles. Photoluminescence is due to charge carrier confinement in such three dimensional structure (sponge-like structure). Characteristics of visible light emission from n-type PS can be explained in terms of modification of band structure accompanied by bandgap widening and localized levels in bandstructure. It is also shown that hydrogen and oxygen atoms existing on residual silicon parts play an important role on emission stability.

• Coupled systems mechanics
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• v.8 no.1
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• pp.1-17
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• 2019

The present paper deals with delamination fracture analyses of the multilayered functionally graded non-linear elastic Symmetric Split Beam (SSB) configurations. The material is functionally graded in both width and height directions in each layer. It is assumed that the material properties are distributed non-symmetrically with respect to the centroidal axes of the beam cross-section. Sine laws are used to describe the continuous variation of the material properties in the cross-sections of the layers. The delamination fracture is analyzed in terms of the strain energy release rate by considering the balance of the energy. A comparison with the J-integral is performed for verification. The solution derived is used for parametric analyses of the delamination fracture behavior of the multilayered functionally graded SSB in order to evaluate the effects of the sine gradients of the three material properties in the width and height directions of the layers and the location of the crack along the beam width on the strain energy release rate. The solution obtained is valid for two-dimensional functionally graded non-linear elastic SSB configurations which are made of an arbitrary number of lengthwise vertical layers. A delamination crack is located arbitrary between layers. Thus, the two crack arms have different widths. Besides, the layers have individual widths and material properties.