• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.07a
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• pp.441-443
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• 2005

According as CCFL(Cold Cathode Fluorescent lamp) of light source in Backlight unit for Note PC (Personal computer) is presently needed to low power consumption and long life time, the development focus of CCFL is going on the discharge gas, phosphor and electrode material. First of all, discharge voltage characteristic of CCFL is closely connected with electrode material For low discharge voltage, the characteristic of electrode material is needed to low work function, low sputtering ratio and superior manufacturing property. We developed new CCFL with Nb/Ni Clad electrode superior to conventional CCFL. Because Nb/Ni Clad electrode with Ni material and Nb material, the electrical characteristic is superior to other electrode materials. The electrode of Nb/Ni Clad is composed that Ni of outside material has superior manufacturing property and Nb of inside material has low work function. Nb/Ni Clad of new electrode material is made by process of Rolling mill at high pressure and heat treatment. We compared electrical characteristic of Nb/Ni clad electrode with conventional Mo electrode by measurement. Mo electrode and Nb/Ni Clad electrode of cup type with diameter 1.1 mm and length 3.0mm are used to this experiment. Material content of Mo electrode is Mo 100%. But, Nb/Ni Clad electrode is composed by content of Nb 40% and Ni 60%. The result of comparison measurement between new CCFL with Nb/Ni Clad electrode and conventional CCFL was appeared that CCFL with Nb/Ni Clad electrode had superior characteristic than conventional CCFL. As a result of experiment, we completed Note PC with low power consumption and long life time by application of new CCFL with Nb/Ni Clad electrode.

• Journal of the Korea institute for structural maintenance and inspection
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• v.8 no.2
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• pp.123-136
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• 2004

Terzaghi's one-dimensional consolidation theory has some important assumption, which can't be applicable to predict the behavior of soft clay ground. Especially, predictions using infinitesimal strain and linear material function related with permeability can give rise to mistake in comparison with the result of real behavior in site. For this reason, Gibson et al. established a rigorous formulation for the one-dimensional nonlinear finite strain consolidation theory, which can consider non-linearity of material function. But it is difficult to apply this theory to predict the behavior of common soft clay ground with vertical drain. In this study, consolidation model which can consider the vertical and horizontal flow of a fully saturated clay layer, self-weight of soil and nonlinear characteristics of compressibility and permeability are derived. Numerical analysis scheme, which can be applied to consolidation analysis by derived consolidation model in this study was developed. The characteristics of material function were examined using laboratory testing such as standard consolidation test, Rowe-cell test and modified consolidation test.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.20 no.6
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• pp.779-787
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• 2007

This paper presents a highly efficient moving least squares finite difference method (MLS FDM) for a heat transfer problem of bi-material with interfacial boundary. The MLS FDM directly discretizes governing differential equations based on a node set without a grid structure. In the method, difference equations are constructed by the Taylor polynomial expanded by moving least squares method. The wedge function is designed on the concept of hyperplane function and is embedded in the derivative approximation formula on the moving least squares sense. Thus interfacial singular behavior like normal derivative jump is naturally modeled and the merit of MLS FDM in fast derivative computation is assured. Numerical experiments for heat transfer problem of bi-material with different heat conductivities show that the developed method achieves high efficiency as well as good accuracy in interface problems.

• Journal of Nutrition and Health
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• v.38 no.1
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• pp.67-75
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• 2005

This study was performed to examine the change of lipid metabolism and immune function caused by antioxidant material in hypercholesterolemic elderly women (serum total cholesterol $\geq$200 mg/dI). The subjects were 51 elderly women aged over 60 yrs. They were divided into antioxidant nutrients complex group (n = 25) and spirulina group (n= 26). Antioxidant nutrients complex (1 capsule/day) and spirulina (7.5 mg/day) were used for intervention for 8weeks. All the subjects were fully informed the purpose of study and gave written consents to participate in this study. Dietary intakes, anthropometric indices and blood assessment for lipid, immune function and antioxidant status were measured before and after supplementation. Either antioxidant nutrients complex or spirulina supplementation for 8weeks resulted in improved antioxidant status evidence by increased TAS (total antioxidant status) and decreased TB-ARS (thiobarbituric acid reactive substance) . This intervention led to decreased serum levels of total cholesterol, LDL-cholesterol, oxLDL, apolipoprotein B, IL-6 and IL-6 production by peripheral blood lymphocyte. In conclusion, the lipid profiles, immune function and antioxidant capacity were improved after either antioxidant nutrient complex or spirulina supplementation for hypercholesterolemic women. Therefore, improving antioxidant status using supplemen-tation could provide means of controlling cardiovascular disease in Korean elderly people.

• The Korean Journal of Community Living Science
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• v.18 no.1
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• pp.39-53
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• 2007

The purpose of this study was to determine the characteristics of an experimental protective clothing material with regard to comfort and isolation from the hazardous heavy metals produced in municipal waste incineration. An analysis was conducted on the total concentrations of heavy metals in some parts such as surface, middle layer, and interior for the treated fabric, and the untreated one, and working clothes. We conclude that the processed fabric with charcoal for working clothes showed the least exposure to heavy metals of the three. Working clothes worn by workers during waste incineration were much more contaminated than the untreated and treated materials. The material of working clothes could be chosen according to the function with regard to its original chemical characteristics, which are the proper results of the dyeing process. The processed fabric material has high degrees of moisture regain, thermal insulation, water vapor penetration, and antibacterial function; consequently, it is much more comfortable to wear. The fabric material proposed in this research contributed much more to blocking heavy metal concentrations (such as Cd, Pb, Cu, Cr, Zn, Mn) than did the fabric of working clothes at present. Consequently, we strongly suggest that the material of working clothes be upgraded by adopting the above-mentioned charcoal-processed fabric. Materials of working clothes must be improved to increase comfort and prevent harmful gas, flying dust, and heavy metals from permeating the fabrics.

• Journal of Powder Materials
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• v.22 no.3
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• pp.175-180
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• 2015

In this study, ternary compound Max Phase $Ti_2AlC$ material was mixed by 3D ball milling as a function of ball milling time. More than 99.5 wt% pure $Ti_2AlC$ was synthesized by using spark plasma sintering method at 1000, 1100, 1200, and $1300^{\circ}C$ for 60 min. The material characteristics of synthesized samples were examined with relative density, hardness, and electrical conductivity as a function of sintering temperature. The phase composition of bulk was identified by X-ray diffraction. On the basis of FE-SEM result, a terraced structures which consists of several laminated layers were observed. And $Ti_2AlC$ bulk material obtained a vickers hardness of 5.1 GPa at the sintering temperature of $1100^{\circ}C$.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.11a
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• pp.869-872
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• 2006

By this time, various shapes and materials are used in Artificial Reef. A function of Artificial Reef is leading of fishes by adhesion of seaweeds, however, this effect was not enough. In this study, porous concrete containing function materials (protein, carbohydrates, and fat etc.) are investigated to maximize leading effect of fishes. For these, the mechanical characteristics of porous concrete are investigated with void contents and function materials. Also, the diffusion of function materials are compared to suggest the suitable content of functional material.

• Journal of Magnetics
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• v.12 no.2
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• pp.72-76
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• 2007

We investigate the spin transfer torque in metallic multilayer system by employing Keldysh non-equilibrium Green function method. We study the dependences of the spin transfer torque on the detailed energy configuration of ferromagnetic, spacer, and lead layers. With Keldysh non-equilibrium Green function method applied to a single band model, we explore spin transfer torque effect in various layer structures and for various material parameters.

• Structural Engineering and Mechanics
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• v.53 no.4
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• pp.703-723
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• 2015

In this paper optimization of volume fraction distribution in a thick hollow cylinder with finite length made of two-dimensional functionally graded material (2D-FGM) and subjected to steady state thermal and mechanical loadings is considered. The finite element method with graded material properties within each element (graded finite elements) is used to model the structure. Volume fractions of constituent materials on a finite number of design points are taken as design variables and the volume fractions at any arbitrary point in the cylinder are obtained via cubic spline interpolation functions. The objective function selected as having the normalized effective stress equal to one at all points that leads to a uniform stress distribution in the structure. Genetic Algorithm jointed with interior penalty-function method for implementing constraints is effectively employed to find the global solution of the optimization problem. Obtained results indicates that by using the uniform distribution of normalized effective stress as objective function, considerably more efficient usage of materials can be achieved compared with the power law volume fraction distribution. Also considering uniform distribution of safety factor as design criteria instead of minimizing peak effective stress affects remarkably the optimum volume fractions.

• Korean Journal of Cognitive Science
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• v.2 no.2
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• pp.205-220
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• 1990

Material substance may exist in two different modes of reality:real as physcal objects that comprise material cause and formal cause, and real as function networks that comprise efficient cause and functional cause.Functional networks are real as a mode of material substance because their efficient cause is energy consuming.Neural functional network, in this sense, are different from neural networks.In the same way, mental functional networks are real, for they are energy consuming and they function as a network.Mental functional networks, in turn, may divide into non-lingustic functional networks and linguistic functional networks.And further distinctions among the different levels of mental functional networks will be specified, and hence their reality confirmed more specifically as the research in cognitive science advances.