• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.11a
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• pp.208-211
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• 2003

In this paper, mechanical property of electric epoxy with water aging was discussed. We studied mechanical property of elastic resin after absorption in water from 0 to 484 hour. As a result, diffusion factor of elastic epoxy showed $20-21{\times}10^{-4}mm^2/s$ and general epoxy showed $9.5{\times}10^{-4}mm^2/s$. Elastic property increased linearly according to amount of addictives and decreased elastic property according to amount of water absorption. Tensile strength was reduced to add to addictives. It was effected by water absorption of micro-void of elastic epoxy. Hardness inclined to decrease after increasing according to absorbed time.

• Journal of the Korean Applied Science and Technology
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• v.19 no.2
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• pp.86-96
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• 2002

Oligomer type anionic surfactants(RmM-Na or RmD-Na} were synthesized from $C_{8}{\sim}C_{16}$ long chain alkylvinylether and maleic anhydride (or maleic diethylether). And also their fluorescent anionic surfactants (RmF- Na) were obtained from alkali neutralization which opens the lactone ring of the condensing materials produced by maleic anhydride alkylvinylether copolymer and 3-aminophenol. The measurement results for the surface active properties of water soluble oligomer type anionic surfactants with fluorescent structure (RmF-Na) exhibited a remarkable surface tension lowing property, foam breaking property, and a ernulsing power.

• Journal of the Korea Computer Graphics Society
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• v.13 no.1
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• pp.25-32
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• 2007

Computer graphics technology has advanced such that all objects can be represented within a computer display. However, because computer displays have a finite resolution, the variety of objects that can be realistically represented together in the same view is restricted by the difference in their relative size. In addition, objects cannot be rendered according to their physical properties in terms of real length units in current computer graphics technology. To solve these problems, we have defined a method that allows objects to be described using real-world physical property units, such as metric units, in a computer graphics system, and developed a 3D browser based on X3D, which implements the concept of relative proportion properties.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.05c
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• pp.31-35
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• 2002

It is hard to expect excellent electrical, mechanical and chemical properties from most of the composite materials presently used as insulators due to insufficient wettability property caused by the difference of interfacial properties between the matrix material and the reinforcer. Therefore, various interfacial coupling agents have been developed to improve the interfacial properties of composite materials. But if the wettable coupling agents are used outdoor for a long time, change in quality takes place in the coupling agents themselves, bringing about deterioration of the properties of the composite materials. In this study, composite materials were put to dry interfacial treatment by use of plasma technology. It has been presented that the optimum parameters for the best wettability of the samples at the time of generation of plasma were oxygen atmosphere, 0.1 torr of system pressure, 100 W of discharge power, and 3 minutes of discharge time. Also, the surface resistance rate and dielectric property were improved.

• Korean Journal of Mathematics
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• v.28 no.3
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• pp.539-554
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• 2020

A set {a₁, a₂, …, a_m} of m distinct positive integers is called a D(-1)-m-tuple if the product of any distinct two elements in the set decreased by one is a perfect square. In this paper, we find a solution of Pellian equations which is constructed by D(-1)-triples and using this result, we prove the extendibility of D(-1)-pair with some conditions.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.10a
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• pp.50-54
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• 2004

A numerical system to extract effective elastic properties of polycrystalline thin-films for MEMS devices is already developed. In this system, the statistical model based on lattice system is used for modeling the microstructure evolution simulation and the key kinetics parameters of given micrograph, grain distributions and deposition process can be extracted by inverse method proposed in the system. In this work, the effects of kinetics parameters on the extraction of effective elastic properties of polycrystalline thin-films are studied by using statistical method. The effects of the fraction of the potential site( $f_{P}$ ) and the nucleation probability( $P_{N}$ ) among the parameters for deposition process of microstructure on the extraction of effective elastic properties of polycrystalline thin-films are studied.d.d.

• Structural Engineering and Mechanics
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• v.15 no.5
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• pp.535-550
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• 2003

In this paper, a boundary-type meshfree method, the boundary radial point interpolation method (BRPIM), is presented for solving boundary value problems of two-dimensional solid mechanics. In the BRPIM, the boundary of a problem domain is represented by a set of properly scattered nodes. A technique is proposed to construct shape functions using radial functions as basis functions. The shape functions so formulated are proven to possess both delta function property and partitions of unity property. Boundary conditions can be easily implemented as in the conventional Boundary Element Method (BEM). The Boundary Integral Equation (BIE) for 2-D elastostatics is discretized using the radial basis point interpolation. Some important parameters on the performance of the BRPIM are investigated thoroughly. Validity and efficiency of the present BRPIM are demonstrated through a number of numerical examples.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09b
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• pp.788-789
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• 2006

Microstructure and soft magnetic properties of bulk amorphous and/or nanocrystalline $Fe_{73.5}Cu_1Nb_3Si_{13.5}B_9$ alloys prepared by consolidation at 5.5GPa were investigated. The relative density of the bulk sample 1 (from amorphous powders) was 98.5% and the grain sizes were about 10.6nm. While the relative density and grain sizes of bulk sample 2 (from nanocrystalline powders) are 98% and 20.1nm, respectively. Particularly, the bulk samples exhibited a good combined magnetic property: for Sample1, $M_s=125emu/g$ and $H_c=1.5Oe;$ for Sample2, $M_s=129emu/g$ and $H_c=3.3Oe$. The success of synthesizing the nanocrystalline Fe-based bulk alloys will be encouraging for the future development of bulk nanocrystalline soft magnetic alloys.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.50 no.2
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• pp.93-99
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• 2001

A new type geometric and mathematical network reduction model is introduced. Large-scale network is analyzed with analytic approach. The graph has many nodes, branches and loops. Circuit equation are obtained from these elements and connection rule. In this paper, the analytic relation between voltage source has a mutual different graphic property. Node-reduction procedure is achieved with this circuit property. Consequently voltage source value is included into the adjacent node-analyzing equation. A resultant model equations are reduced as much as voltage source number. Matrix rank is (n-1-k), where n, k is node and voltage source number. The reduction procedure is described and verified with geometric principle and circuit theory. Matrix type circuit equation can be composed with this technique. The last results shall be calculated by using computer.

• Journal of the Semiconductor & Display Technology
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• v.9 no.3
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• pp.71-74
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• 2010

In this study the optical properties, such as relative transmittance and reflectance of PDP were analyzed with 3D optical code. Because of the electrode structure, the reference model shows 21.3 % higher transmittance than the test model and the reference model shows 16.6 % higher reflectance than the test model. The calculated reflectance of reference and test models is compared to the measured reflectance and the difference between calculation and measurement is 4.9 %.