• Journal of Forest and Environmental Science
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• v.14 no.1
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• pp.89-100
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• 1998

The study was carried to investigate the change of internal stress and physical properties of paper by the mutiplying of paper structuring that is an useful means to maximize the performance and use of the fiber raw material. The effects of recycled fiber on the physical properties of multiplied paper also were studied. The beating increased the internal stress of single layered paper, while filler loading decreased the internal stress. Multiplying the structure of paper decreased the internal stress and the most of physical properties except for tear index. It was found that the properties of paper could be changed by the pulp type, beating and the combination of raw materials. The introduction of filler in the middle and/or outer layer could improved the internal stress, tensile index, tear index and burst index. The addition of recycled fiber increased the opacity and stiffness of paper in both single layered and multiplied paper. Multiplying the structure of paper improved the air permeability and stiffness, while decreased burst index.

• Journal of the Earthquake Engineering Society of Korea
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• v.8 no.5 s.39
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• pp.25-33
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• 2004

To evaluate the seismic capacity of a multistorey building structures in performance based seismic design, it is needed to convert MDOF model into equivalent SDOF model. This paper presents predictions for interstory drift of multistorey structures using method of converting a MDOF system into an equivalent SDOF model. The principal objective of this investigation is to evaluate appropriateness of converting method through performing nonlinear time history analysis of a multistory building structures and an equivalent SDOF model. Comparing the interstory drift of multistorey structures calculated by time history analysis and those evaluated by an equivalent SDOF model, the adequacy and the validity of converting method is verified. The conclusion of this study is following; A method of converting a MDOF system into an equivalent SDOF model through the nonlinear time history response analysis is valid. Inelastic first mode shapes are expected to be more accurate than elastic first mode shapes in obtaining interstory drift of multistorey structures from equivalent SDOF model.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.39 no.3
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• pp.73-84
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• 2002

Fast and accurate new capacitance determination methodology for non-uniform complicated multi-layer VLSI interconnects is presented. Since a capacitance determination of intricate multi-layer interconnects using 3-dimensional field-solver is not practical, quasi-3-dimensional methodology is presented. Interconnects with discontinuity (i.e., bend structure and different spacing between lines, etc.) are partitioned. Then, each partial capacitance of divided parts is extracted by using 2-dimensional extraction methodology. For a multi-layer interconnects with shielding layer, the system can be simplified by investigating a distribution of charge in it. Thereby, quasi-3-dimensional capacitance for multi-layer interconnects can be determined by combining solid-ground based 2-dimensional capacitance and shielding effect which is independently determined with layout dimensions. This methodology for complicated multi-layer interconnects is more accurate and cost-efficient than conventional 3-dimensional methodology It is shown that the quasi-3-dimensional capacitance methodology has excellent agreement with 3-dimensional field- solver-based results within 5% error.

• The Journal of the Acoustical Society of Korea
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• v.32 no.4
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• pp.301-307
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• 2013

SONAR detection performance is one of the key survivability factors in underwater weapon systems. In order to catch the acoustic ability of SONAR, multilayer SONAR structures are analyzed using the elastic theory. The applied results for the simple models are compared with those from commercial program, ANSYS, and the reliable results are obtained. The analysis of sound pressure level (SPL) and echo reduction (ER) by the thickness change of multilayer SONAR structures are performed using the verified elastic theory. As the thickness of anechoic layer is increased, SPL is distributed evenly and ER is increased slightly with the frequency. In decoupling layers and steel layers, SPL are hardly changed and ER is slightly decreased with the thickness increase of those layers. SPL and ER are not affected by the thickness change of the carbon reinforced plastic (CRP) layer. Therefore, to improve the acoustic ability of multilayer SONAR structures, the thickness increase of the anechoic layer and minimization of the decoupling layer, steel layer and CRP layer are desirable.

• Applied Chemistry for Engineering
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• v.10 no.5
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• pp.711-717
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• 1999

A multilayer-structure material containing ductile and brittle layer simultaneously was examined and compared with a single layer material using fracture mechanical properties. We found that impact strength of multilayer structure material was considerably higher than single layer's and toughness was enhanced by about two times or higher in similar glass transition temperature($T_g$) region and the same dimension. The superposition principle of impact pulse was used for interpretation of kinetic stress wave as a high-velocity crack proceeds in the plastic. It was understood that the optimum condition of ductile/brittle thickness ratio could be designed in the final toughness enhancement of multilayer.

• Journal of the Korean Society of Radiology
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• v.4 no.4
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• pp.33-36
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• 2010

Multilayer mirrors are very useful for applications of high energy X-ray. X-rays of high energy require very small thickness, a few nanometers, in the d-spacing of a multilayer mirror. Each layer is composed of a multilayr mirror influences to interfacial roughness or interdiffusion which gives rise to degrade specular reflection. Carbon layer of 1 nm thick in a C/W multilayer mirror of 3.25 nm d-spacing was examined. Carbon as well as tungsten layers were very uniform, and there was no micro-structure in carbon layers. However, interdiffusion between carbon and tungste layers was observed by a transmission electron microscope.

• The Journal of the Acoustical Society of Korea
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• v.13 no.4
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• pp.60-68
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• 1994

In this paper we propose a new Hybrid learning rule applied to multilayer feedforward neural networks, which is constructed by combining Hebbian learning rule that is a good feature extractor and Back-Propagation(BP) learning rule that is an excellent classifier. Unlike the BP rule used in multi-layer perceptron(MLP), the proposed Hybrid learning rule is used for uptate of all connection weights except for output connection weigths becase the Hebbian learning in output layer does not guarantee learning convergence. To evaluate the performance, the proposed hybrid rule is applied to classifier problems in two dimensional space and shows better performance than the one applied only by the BP rule. In terms of learning speed the proposed rule converges faster than the conventional BP. For example, the learning of the proposed Hybrid can be done in 2/10 of the iterations that are required for BP, while the recognition rate of the proposed Hybrid is improved by about $0.778\%$ at the peak.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.3 no.2
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• pp.313-319
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• 1999

We devise the 3 models of Multilayered Recurrent Prediction Neural Network(MLRPNN), which are obtained by modifying the Multilayered Perceptron(MLP) with 4 layers. We experimentally study the speech recognition performance of 3 models by a comparative method, according to the variation of the prediction order, the number of neurons in two hidden layers, initial values of connecting weights and transfer function, respectively. By the experiment, the recognition performance of each MLRPNN is better than that of MLP. At the model that returns the output of the upper hidden layer to the lower hidden layer, the recognition performance shows the best value. All MLRPNNs, which have 10 or 15 neurons in the upper and lower hidden layer and is predicted by 3rd or 4th order, show the improved speech recognition rate. On learning, these MLRPNNs have a better recognition rate when we set the initial weights between -0.5 and 0.5, and use the unipolar sigmoid transfer function in the lower hidden layer.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.12
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• pp.670-677
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• 2016

Laboratory and meta-analyses were done for 9% NI Steel for use in a liquefied natural gas carrier. The meta-analysis is based on a previous study. The laboratory analysis examines the effects of a single pass and multiple passes on the tensile strength through an impulse-response test. The tensile strength increased from pass one to pass three and decreased from pass four to pass ten. The pass and multi-pass welding had a positive effect on the tensile strength. Lastly, the welding and tensile time had a positive effect on the tensile strength.

• Journal of IKEEE
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• v.22 no.2
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• pp.302-308
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• 2018

Multi-Layer Sputtering is aim to develop desired thickness thin film multi-layer with different materials. The multi-layer thin film deposition process occupies a relatively large portion in the process time, because the main reason is that it takes much time to move the substrate to be deposited and to make the chamber into a high vacuum state compared to the process time. Most of semiconductor and display industries sputter a single substance in one chamber and move boards through multi-continuous robots to another chamber to sputter other materials. This will inevitably require multiple chambers, vacuum pumps, and multi-contamination robots within the process facility. To solve these problems, this paper proposes a control system for multi-layer thin film sputtering devices that deposit different materials within a single vacuum chamber and is applied in TFT process. The manufacture and experiment of the control system proved its validity.