• 한국정보통신설비학회:학술대회논문집
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• 2007.08a
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• pp.336-340
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• 2007

This paper proposes a multicast scheme over IEEE 802.16 networks which support multiple upper layer protocols such as ATM, IPv4 packets, IPv6 packets, IEEE 802.3 over IPv4 and so on. The multicast capabilities over IEEE 802.16 are important both control plane and data plane. The proposed multicast scheme can be divided into two types: direct mapping and indirect mapping. The direct mapping scheme is that layer 3 address is directly mapped into CID information which is used for connection identifier at IEEE 802.16 link layer. The indirect mapping scheme has two steps for mapping between layer 3 address and layer 2 CID. Firstly, a layer 3 address translates to Ethernet MAC address with group MAC address. Secondly, a group MAC address is mapped into CID. The mapping scheme depends on the upper layer protocols.

• 한국정보디스플레이학회:학술대회논문집
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• 2002.08a
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• pp.766-769
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• 2002

We have seen the effects of hole-injection buffer layer in organic light-emitting diodes using copper phthalocyanine(CuPc), poly(vinylcarbazole)(PVK), and Poly(3,4-ethylenedioxythiophene):poly(styrene-sulfonate)(PEDOT:PSS) in a device structure of ITO/buffer/TPD/$Alq_3$/Al. Polymer PVK and PEDOT:PSS buffer layer was made using spin casting method and the CuPc layer was made using thermal evaporation. Current-voltage characteristics, luminance-voltage characteristics and efficiency of device were measured at room temperature with a thickness variation of buffer layer. We have obtained an improvement of the external quantum efficiency by a factor of two, four, and two and half when the CuPc, PVK, and PEDOT:PSS buffer layer are used, respectively. The enhancement of the efficiency is attributed to the improved balance of holes and elelctrons due to the use of hole-injection buffer layer. The CuPc and PEDOT:PSS layer functions as a hole-injection supporter and the PVK layer as a hole-blocking one.

• Journal of the Korean Graphic Arts Communication Society
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• v.29 no.3
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• pp.125-132
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• 2011

Is very simple in tension work of screen mesh for effective printing if worker uses screen mesh of player who desire at screen print process. General method is methods that use mesh of player who want on screen frame as screen plate because tensioned. The single layer screen plate was made from one sheet screen mesh and the double layer screen plate was made from two sheets screen mesh overlapped. The thickness of sensitive emulsion applied to double layer screen plate is more thicker than two time s of thickness of emulsion applied to single layer screen plate. It seems that the sensitive emulsion inserted between an upper layer and a lower layer of double layer screen mesh.

• Journal of Korea Multimedia Society
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• v.19 no.12
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• pp.1951-1959
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• 2016

In this paper, we propose a two-scale fusion method for infrared and visible images using saliency and variance. The images are separated into two scales respectively: a base layer of low frequency component and a detailed layer of high frequency component. Then, these are synthesized using weight. The saliencies and the variances of the images are used as the fusion weights for the two-scale images. The proposed method is tested on several image pairs, and its performance is evaluated quantitatively by using objective fusion metrics.

• Ceramist
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• v.21 no.2
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• pp.19-28
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• 2018

Coulomb drag is an effective probe into interlayer interaction between two electron systems in close proximity. For example, it can be a measure of momentum, phonon, or energy transfer between the two systems. The most exotic phenomenon would be when bosonic indirect excitons (electron-hole pairs) are formed in double layer systems where electrons and holes are populated in the opposite layers. In this review, we present various drag phenomena observed in different double layer electron systems, e.g. GaAs/AlGaAs heterostructures and two-dimensional material based heterostructures. In particular, we address the different behavior of Coulomb drag depending on its origin such as momentum or energy transfer between the two layers and exciton condensation. We also discuss why it is difficult to achieve electron-hole pairs in double layer electron systems in equilibrium.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.02a
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• pp.337-337
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• 2011

The elecronic absorption and surface morphology evolution of two types of molecular double layer thin films, copper phthalocyanine(CuPc) layer deposited on top of chloro[subphtalocyaninato]boron(III) (SubPc) layer, denoted as SubPc/CuPc, and vice versa, at various thicknesses were invertigated using ultraviolet(UV)-visible spectroscopy and atomic force microscopy (AFM). Both types of double layer structures showed similar broadened absorption patterns in UV-visible region which were well consistent with fitted spectra by a simple linear combination of single layer absorption spectra of two materials. In contrast, the surface morphology of double layer structures was dependent on the order of deposition. For CuPc/SubPc structures, the surface morphology was characterized by elongated grains, characteristic of SubPc thin films, indicating the morphological influence of underlying CuPc layer on subsequent SubPc layer was not large. For SubPc/CuPc structures, however, the underlying SubPc layer acted as a morphological template for the subsequently deposited CuPc layer. It was also observed that the grain size of CuPc layer varied by the thickness of underlying SubPc layer.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2008.11a
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• pp.71-81
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• 2008

This paper proposes a spectral element which can represent dynamic responses in high frequency domain such as Lamb waves on a thin plate. A two layer beam model under 2-D plane strain condition is introduced to simulate high-frequency dynamic responses induced by piezoelectric layer (PZT layer) bonded on a base plate. In the two layer beam model, a PZT layer is assumed to be rigidly bonded on a base beam. Mindlin-Herrmann and Timoshenko beam theories are employed to represent the first symmetric and anti-symmetric Lamb wave modes on a base plate, respectively. The Bernoulli beam theory and 1-D linear piezoelectricity are used to model the electro-mechanical behavior of a PZT layer. The equations of motions of a two layer beam model are derived through Hamilton's principle. The necessary boundary conditions associated with electro mechanical properties of a PZT layer are formulated in the context of dual functions of a PZT layer as an actuator and a sensor. General spectral shape functions of response field and the associated boundary conditions are formulated through equations of motions converted into frequency domain. A detailed spectrum element formulation for composing the dynamic stiffness matrix of a two layer beam model is presented as well. The validity of the proposed spectral element is demonstrated through comparison results with the conventional 2-D FEM and the previously developed spectral elements.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.25 no.6
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• pp.68-74
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• 2011

The touch or step voltages which exist in the vicinity of a grounding electrode are closely related to the earth structure and resistivity and the ground current. The grounding design approach is required to determine the grounding electrode location where the hazardous voltages are minimized. In this paper, in order to propose a method of mitigating the electric shock hazards caused by the ground surface potential rise in the vicinity of a counterpoise, the hazards relevant to touch voltage were evaluated as a function of the soil resistivity ratio $\rho_2/\rho_1$ for several practical values of two-layer earth structures. The touch voltage and current on the ground surface just above the test electrode are calculated with CDEGS program. As a consequence, it was found that burying a grounding electrode in the soil with low resistivity is effective to reduce the electric shock hazards. In the case that the bottom layer soil where a counterpoise is buried has lower resistivity than the upper layer soil, when the upper layer soil resistivity is increased, the surface potential is slightly raised, but the current through the human body is reduced with increasing the upper layer soil resistivity because of the greater contact resistance between the earth surface and the feet. The electric shock hazard in the vicinity of grounding electrodes is closely related to soil structure and resistivity and are reduced with increasing the ration of the upper layer resistivity to the bottom layer resistivity in two-layer soil.

• Journal of information and communication convergence engineering
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• v.4 no.4
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• pp.158-161
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• 2006

[ $Bi_2Sr_2Ca_nCu_{n+1}O_y(n{\geq}0)$ ] thin film is fabricatedvia two different processes using an ion beam sputtering method i.e. co-deposition and layer-by-layer deposition. A single phase of Bi2212 can be fabricated via the co-deposition process. While it cannot be obtained by the layer-by-layer process. Ultra-low growth rate in our ion beam sputtering system brings out the difference in Bi element adsorption between the two processes and results in only 30% adsorption against total incident Bi amount by layer-by-layer deposition, in contrast to enough Bi adsorption by co-deposition.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.11 no.10
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• pp.897-902
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• 1998

We prepared Organic LED with a two layer structure by vacuum evaporation. The diode consisted of hole transfer layer (thickness of 30, 50, 70 nm) and electron transfer layer (thickness of 70, 50, 30 nm) material, which was N, N'-diphenyl- N, N'-bis-(3-methyl phenyl)-1,1'-diphenyl-4,4'-diamine)(TPD) and tris(8-hydroxy quinoline) aluminum(Alq3), respectively. We investigated EL properties of the LED with various thickness and cathode electrode. The best results were obtained when thickness of the electron layer is equal to that of emission layer and when AlLi alloy was used as a cathode. The EL intensity, luminance and efficiency of organic LED with equal of layer thick were improved seven, three and two times, respectively. Alq3 was ionized by carrier injection from cathode and could produce exitons. After electron-hole pairs were formed by combination of the electrons and holes at the emission layer, Alq3 layer emitted light.