• Title/Summary/Keyword: layer by layer

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Application of Low-hydrogenated Diamond-like Carbon Film to Mo-tip Field Emitter Array (낮은 수소 함유량을 갖는 유사 다이아몬드 박막의 몰리브덴 팁 전계 방출 소자 응용)

  • Ju, Byeong-Kwon;Jung, Jae-Hoon;Lee, Yun-Hi;Kim, Hoon;Oh, Myung-Hwan
    • The Transactions of the Korean Institute of Electrical Engineers C
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    • v.48 no.2
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    • pp.76-79
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    • 1999
  • Low-hydrogenated DLC films were coated on the Mo-tip FEAs by 'layer-by-layer' process based on the plasma-enhanced CVD method. The hydrogen content in the DLC film deposited by the 'layer-by-layer' process was appeared to be remarkably lowered through SIMS analysis. Also, the low-hydrogenated DLC-coated Mo-tip FEA showed good potentiality for FED applications in terms of turn-on voltage, emission current, emission stability and light emitting uniformity.

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Study of the Effects of ZnO Intermediate Layer on Photoluminescence Properties of Magnetron Sputtering Grown GaN Thin Films (ZnO Intermediate Layer가 GaN 박막의 PL 특성에 미치는 영향 연구)

  • 성웅제;이용일;박천일;최우범;성만영
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2001.07a
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    • pp.574-577
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    • 2001
  • GaN thin films on sapphire were grown by rf magnetron sputtering with ZnO buffer layer. The dependence of GaN film quality on ZnO buffer layer was investigated by X-ray diffraction(XRD). The improved film quality has been obtained by using thin ZnO buffer layer. Using Auger electron spectroscopy(AES), it was observed that the annealing process improved the GaN film quality. The surface roughness according to the annealing temperatures(700, 900, 1100$^{\circ}C$) were investigated by AFM(atomic force microscopy) and it was confirmed that the crystallization was improved by increasing the annealing temperature. Photoluminescence at 8K shows a near-band-edge peak at 3.2eV with no deep level emission.

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Fabrication of multi-layer $high-T_c$ superconducting tapes by a rolling process (로울링법을 이용한 고온 초전도 다심선재 제조)

  • 김민기;허원일;최명호;한병성
    • Electrical & Electronic Materials
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    • v.9 no.6
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    • pp.600-604
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    • 1996
  • High-T$_{c}$, superconducting wire is very important element for the application of electrical power systems. But it is very difficult to develope the long high T, wire with excellent properties. BiSrCaCuO multi-layer tapes are fabricated by a rolling method and pressing method sintered for several step at 840.deg. C. The critical current densities of 637 filament multi-layer tapes sintering 100 hours fabricated by the rolling method and pressing method are 1.3*10$^{4}$ A/cm$^{2}$ and 5.5*10$^{3}$ A/cm$^{2}$. The critical cur-rent densites of multi-layer tapes made by rolling method are found to be better than those fabricated by the powder-in-tube method and pressing process. As result, the rolling method is the best way to fabricated the multi-layer filament.t.

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Synthesis of Microaglae-Capturing Magnetic Microcapsule Using CaCO3 Microparticles and Layer-by-Layer Coating

  • Lee, Young-Hee;Seo, Jung-Cheol;Oh, You-Kwan;Lee, Kyubock
    • Korean Journal of Materials Research
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    • v.28 no.7
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    • pp.376-380
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    • 2018
  • Microalgae produce not only lipids for biodiesel production but also valuable biochemicals which are often accumulated under cellular stress mediated by certain chemicals. While the microcarriers for the application of drug delivery systems for animal cells are widely studied, their applications into microalgal research or biorefinery are rarely investigated. Here we develope dual-functional magnetic microcapsules which work not only as flocculants for microalgal harvesting but also potentially as microcarriers for the controlled release of target chemicals stimulating microalgae to enhance the accumulation of valuable chemicals. Magnetic microcapsules are synthesized by layer-by-layer(LbL) coating of PSS-PDDA on $Fe_3O_4$ nanoparticle-embedded $CaCO_3$ microparticles followed by removing $CaCO_3$ sacrificial templates. The positively charged magnetic microcapsules flocculate microalgae by electrostatic interaction which are sequentially collected by the magnetophoretic separation. The microcapsules with a polycationic outer layer provide efficient binding sites for negatively charged microalgae and by that means are further utilized as a chemical-delivery and flocculation system for microalgal research and biorefineries.

Processing Techniques of Layer Channel Image for 3D Image Effects (3D 영상 효과를 위한 레이어 채널 이미지의 처리 기법)

  • Choi, Hak-Hyun;Kim, Jung-Hee;Lee, Myung-Hak
    • The Journal of the Korea Contents Association
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    • v.8 no.1
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    • pp.272-281
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    • 2008
  • A layer channel, which can express effects on 3D image, is inserted to use it on application rendering effectively. The current method of effect rendering requires individual sources in storage and image processing, because it uses individual and mixed management of images and effects. However, we can save costs and improve results in images processing by processing both image and layer channels together. By changing image format to insert a layer channel in image and adding a hide function to conceal the layer channel and control to make it possible to approach image and layer channels simultaneously during loading image and techniques hiding the layer channel by changing image format with simple techniques, like alpha blending, etc., it is developed to improve reusability and be able to be used in all programs by combining the layer channel and image together, so that images in changed format can be viewed in general image viewers. With the configuration, we can improve processing speed by introducing image and layer channels simultaneously during loading images, and reduce the size of source storage space for layer channel images by inserting a layer channel in 3D images. Also, it allows managing images in 3D image and layer channels simultaneously, enabling effective expressions, and we can expect to use it effectively in multimedia image used in practical applications.

Performance and Stability Evaluation of Muscle Activation (EMG) Measurement Electrodes According to Layer Design (근활성도(EMG) 측정 전극 레이어 설계에 따른 성능 및 안정성 평가)

  • Bon-Hak Koo;Dong-Hee Lee;Joo-Yong Kim
    • Science of Emotion and Sensibility
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    • v.26 no.4
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    • pp.41-50
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    • 2023
  • This study aims to develop electromyography (EMG) textile electrodes and assess their performance and signal stability by examining variations in layer count and fabric types. We fabricated the electrodes through layering and pressing techniques, focusing on configurations with different layer counts (Layer-0, Layer-1, and Layer-2). Our findings indicate that layer presence significantly influences muscle activation measurements, with enhanced performance correlated with increased layer numbers. Subsequently, we created electrodes from five distinct fabrics (neoprene, spandex cushion, 100% polyester, nylon spandex, and cotton canvas), each maintaining a Layer-2 structure. In performance tests, nylon spandex fabric, particularly heavier variants, outperformed others, while the spandex cushion electrodes showed superior stability in muscle activation signal acquisition. This research elucidates the connection between electrode performance and factors like layer number and electrode-skin contact area. It suggests a novel approach to electrode design, focusing on layer properties and targeted pressure application on specific sensor areas, rather than uniformly increasing sleeve pressure.

Improvement of Wear Resistance of Aluminum by Metal-Ceramic Particle Composite Layer (알루미늄표면에 금속-세라믹입자 복합첨가에 의한 내마모성개선)

  • ;;;中田一博;松田福久
    • Journal of Welding and Joining
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    • v.15 no.6
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    • pp.96-104
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    • 1997
  • The present study was aimed to correlate the microstructure and the hardness as well as the wear resistance of the metal-ceramic particulated composite layer on the pure Al plate. The composite layers were constructed by the addition of TiC particles on the surface of Al-Cu alloyed layers by PTA overlaying process. Initially, the Al-Cu alloyed layers were achieved by the deposition of Al-(25 ~ 48%) Cu alloys on the pure Al plate by TIG process. It was revealed that TiC particles were uniformly dispersed without any reaction with matrix in the composite layer. The volume fraction of TiC particles (TiC V F) increased from 12% to 55% with increasing the number of pass of composite layer. Hardnesses of (Al-48%Cu + TiC (3&4layers)) composite layer were Hv450 and Hv560, respectively, due to the increase of TiC V/F. Hardnesses of (Al-Cu + TiC) composite layers decreased gradually with insreasing temperature from 100$^{\circ}$C to 400$^{\circ}$C, and hardnesses at 400$^{\circ}$C were then reached to 1/5 - 1/10 of room temperature hardness depending on the construction of composite layers. The Specific wear of (Al + Tic) layer and Al-48%Cu alloyed layer decreased to 1/10 of the of pure Al, while the specific wear of (Al-48%Cu + TiC (4 layers)) composite layer exhibited 1/15 of that of steel such as SS400 and STS304.

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Modified Error Back Propagation Algorithm using the Approximating of the Hidden Nodes in Multi-Layer Perceptron (다층퍼셉트론의 은닉노드 근사화를 이용한 개선된 오류역전파 학습)

  • Kwak, Young-Tae;Lee, young-Gik;Kwon, Oh-Seok
    • Journal of KIISE:Software and Applications
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    • v.28 no.9
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    • pp.603-611
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    • 2001
  • This paper proposes a novel fast layer-by-layer algorithm that has better generalization capability. In the proposed algorithm, the weights of the hidden layer are updated by the target vector of the hidden layer obtained by least squares method. The proposed algorithm improves the learning speed that can occur due to the small magnitude of the gradient vector in the hidden layer. This algorithm was tested in a handwritten digits recognition problem. The learning speed of the proposed algorithm was faster than those of error back propagation algorithm and modified error function algorithm, and similar to those of Ooyen's method and layer-by-layer algorithm. Moreover, the simulation results showed that the proposed algorithm had the best generalization capability among them regardless of the number of hidden nodes. The proposed algorithm has the advantages of the learning speed of layer-by-layer algorithm and the generalization capability of error back propagation algorithm and modified error function algorithm.

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Tension Estimation of Tire using Neural Networks and DOE (신경회로망과 실험계획법을 이용한 타이어의 장력 추정)

  • Lee, Dong-Woo;Cho, Seok-Swoo
    • Journal of the Korean Society for Precision Engineering
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    • v.28 no.7
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    • pp.814-820
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    • 2011
  • It takes long time in numerical simulation because structural design for tire requires the nonlinear material property. Neural networks has been widely studied to engineering design to reduce numerical computation time. The numbers of hidden layer, hidden layer neuron and training data have been considered as the structural design variables of neural networks. In application of neural networks to optimize design, there are a few studies about arrangement method of input layer neurons. To investigate the effect of input layer neuron arrangement on neural networks, the variables of tire contour design and tension in bead area were assigned to inputs and output for neural networks respectively. Design variables arrangement in input layer were determined by main effect analysis. The number of hidden layer, the number of hidden layer neuron and the number of training data and so on have been considered as the structural design variables of neural networks. In application to optimization design problem of neural networks, there are few studies about arrangement method of input layer neurons. To investigate the effect of arrangement of input neurons on neural network learning tire contour design parameters and tension in bead area were assigned to neural input and output respectively. Design variables arrangement in input layer was determined by main effect analysis.

Crack behaviour of top layer in layered rocks

  • Chang, Xu;Ma, Wenya;Li, Zhenhua;Wang, Hui
    • Geomechanics and Engineering
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    • v.16 no.1
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    • pp.49-58
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    • 2018
  • Open-mode cracks could be commonly observed in layered rocks. A concept model is firstly used to explore the mechanism of the vertical cracks (VCs) in the top layer. Then the crack behaviour of the two-layer model is simulated based on a cohesive zone model (CZM) for layer interfaces and a plastic-damage model for rocks. The model indicates that the tensile stress normal to the VCs changes to compression if the crack spacing to layer thickness ratio is lower than a threshold. The results indicate that there is a threshold for interfacial shear strength that controls the crack patterns of the layered system. If the shear strength is lower than the threshold, the top layer is meshed by the VCs and interfacial cracks (ICs). When the shear strength is higher than the threshold, the top layer is meshed by the VCs and parallel cracks (PCs). If the shear strength is comparative to the threshold, a combining pattern of VCs, PCs and ICs for the top layer can be formed. The evolutions of stress distribution in the crack-bound block indicate that the ICs and PCs can reduce the load transferred for the substrate layer, and thus leads to a crack saturation state.