• Carbon letters
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• v.10 no.4
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• pp.320-324
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• 2009

We investigated the effect of diameter and content of carbon nanotubes (CNTs) on the physical properties of styrenebutadiene rubber (SBR)/CNTs nanocomposites. CNTs-reinforced SBR nanocomposites were prepared by the melt mixing process. CNTs with different diameters were synthesized by the chemical vapor deposition method (CVD). In this work, the mechanical property and other physical properties of SBR/CNTS nanocomposites were discussed as a function of the content and diameter of CNTs.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.07a
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• pp.121-124
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• 2004

We have grown GaN layers with in-situ SiN mask by metal organic chemical vapor deposition(MOCVD) and study the physical properties of the GaN layer. We have also investigate the effect of the SiN mask on its optical property. By inserting a SiN mask, (102) the full width at half maximum(FWHM) decreased from 480 arcsec to 409 arcsec. The PL intensity of GaN with SiN mask improved 2 times to that without SiN mask. We have thus shown that the SiN mask improved significantly the physical and optical properties of the GgN layer.

• Journal of Korea Multimedia Society
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• v.11 no.8
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• pp.1146-1159
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• 2008

This paper proposes a method for determining material property of a haptic model which represents the haptic behavior of a target object. This paper also presents a haptic rendering framework. We adapt elastography to obtain the physical property of a target object. One of the key differences between the proposed framework and a traditional method is that the physical property of the target object can be easily set into a haptic model. For evaluating the proposed method, we construct a real-time palpation prototype simulator. In our work, a human liver is selected as a target object and the liver is represented by Shape-retaining Chain Linked Model(S-chain model) for satisfying the real-time performance. We conduct experiments whether a user easily distinguishes abnormal portions from normal portions. From the experimental results, we evaluate that the proposed method provides the discriminable force to users in real-time.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.14 no.12
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• pp.979-986
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• 2001

This paper was researched the effect of slurry stability on the mechanical and electrical property of the porcelain insulator with various raw materials such as feldspar, quartz, clay and l7wt% alumina. The slurry was fabricated after ball milling the mixed raw materials. Green compacts were made by the extrusion and were sintered at 1300$\^{C}$ for 60min in the tunnel kiln. All of the specimens were densified 96% of the theoretical density. The 3-point flexural strength($\sigma$$\_$B/) of the specimen stabilized slurry pH 7.8 was 1650 k9/㎠ and the vickers hardness(Hv) and the fracture toughness(K$\_$IC/) were 27.5 GPa and 2.2 MPa$.$m$\^$$\sfrac{1}{2}$/, respectively. The mechanical properties of the specimen stabilized slurry PH 9.3 were 1716 kg/㎠($\sigma$$\_$B/), 27.6 GPa(Hv) and 3.0 MPa$.$m$\^$$\sfrac{1}{2}$/(K$\_$IC/), respectively. The dielectric strength was increased from 8.3kV/mm to 13.2kV/mm as the increase of the slurry pH from 7.8 to 9.3. Therefore the physical properties of the specimen stabilized slurry pH 9.3 were improved.

• International Journal of Concrete Structures and Materials
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• v.18 no.1E
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• pp.23-28
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• 2006

In this study, the general theory of fractality is discussed to provide a fundamental understanding of fractal geometry applied to heterogeneous material surfaces like pavement surface and rock surface. It is well known that many physical phenomena and systems are chaotic, random and that the features of roughness are found at a wide spectrum of length scales from the length of the sample to the atomic scales. Studying the mechanics of these physical phenomena, it is absolutely necessary to characterize such multi scaled rough surfaces and to know the structural property of such surfaces at all length scales relevant to the phenomenon. This study emphasizes the role of fractal geometry to characterize the roughness of various surfaces. Pavement roughness and rock surface roughness were examined to correlate their roughness property to fractality.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.05b
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• pp.509-512
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• 2006

We have many environmental problems by the polluted materials as a results of mechanical development these days. So people want to use building products made from natural things and take a good effect for people from those bio products. We can instance electron wave shelding, far infrared ray and anion emission, and anti-bacterial property as the latest trend of the bio building material. So we had a experiment to investigate how much bio materials affect concrete when we use in the concrete with cement substitution. We tested slump, 7days compressive strength, and air contents for physical properties of bio concrete. The result is that bio concretes with four bio ingredients have proper values comparing with target values for slump and air content but lower compressive strength than plain concrete.

• Journal of the Korean Society of Food Science and Nutrition
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• v.23 no.2
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• pp.298-302
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• 1994

This study is carried out in order to investigate to the physical property of Castella. The material is 19 kinds of Castella on the market in Kyushu area.As an result of the sensory evaluation for Castella, it could be classified into 3 types ; a) high grade, C) low grade, and B) midium grade.The results are summarized as follow. The water content of 3 type Castella was most 26-30% but Korea's was more lower . ΔE of A an dB type Castella was similiar , but A and C types was very different. in the Creep test, 3 types are all the 6-element Voigt model, consisting of Hookean body , Newtonian body and two sets of Voigt body. Eo of A type is 13-36% higher than other types. The parts of retardation strain of A type are 21-41% lower than B type, 8-13% higher than C type, respectively.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.27 no.12
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• pp.767-775
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• 2014

New material design has obtained tremendous attention in material science community as the performance of new materials, especially in nano length scale, could be greatly improved to applied in modern industry. In certain conditions limiting experimental synthesis of these new materials, new approach by computer simulation has been proposed to be applied, being able to save time and cost. Recent development of computer systems with high speed, large memory, and parallel algorithms enables to analyze individual atoms using first principle calculation to predict quantum phenomena. Beyond the quantum level calculations, mesoscopic scale and continuum limit can be addressed either individually or together as a multi-scale approach. In this article, we introduced current endeavors on material design using analytical theory and computer simulations in multi-length scales and on multi-physical properties. Some of the physical phenomena was shown to be interconnected via a cross-link rule called 'cross-property relation'. It is suggested that the computer simulation approach by multi-physics analysis can be efficiently applied to design new materials for multi-functional characteristics.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.11a
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• pp.29-29
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• 2008

Platinum Thin films were deposited on $Al_2O_3$ by Rf magnetic Sputtering. The physical and electrical characteristics of these films were analyzed under various deposition conditions(Ar gas pressure, input power, substrate temperature.) and annealing condition. The deposition rate was increased with increasing the input power but not increased linear. In the other factor, The Pt thin films property was associated with resistance. so lower resistance had more and more good Pt thin films condition. For the purpose of this study, we will get the best Pt thin film characteristics.

• Proceedings of the KSME Conference
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• 2003.04a
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• pp.113-118
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• 2003

Stress and displacement fields for a propagating crack in a functionally gradient material (FGM) which has exponentially varying elastic and physical properties along the direction of the crack propagation, are derived. The equations of motion in nonhomogeneous material are developed using displacement potentials. The solutions to the displacement fields and the stress fields for a crack propagating at constant speed along the gradient are obtained through an asymptotic analysis. The influences of nonhomogeneity on the higher order terms of the stress fields are explicitly brought out. Using these stress components, isochromatic fringes around the stationary crack are generated at crack for different nonhomogeneity and the effects of nohonhomgeneity on these fringes are discussed.