• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.08a
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• pp.89-92
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• 2003

ITO thin films were deposited by RF-magnetron sputtering method and crystallization behavior of the films with and without external heating as a function of deposition time was examined. X-ray diffraction results indicated an amorphous state of the film when the deposition time is short about 10 min. When the deposition time was increased over 20 min development of crystallization of the films is observed. Because RF-sputtering transfers the high-energy to the growing film by energetic bombardment, it is believed that considerable activation energy for the crystallization of the film has transferred during deposition, which resulted in the crystallization of ITO thin films without external energy supply.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.17 no.2
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• pp.127-137
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• 2004

We have investigated the structures, the energetic, and the nanomechanics of the single-wall boron-, aluminum-, and gallium-nitride nanotubes using atomistic simulations based on the Tersoff-type potential. The Tersoff-type potential for the III-nitride materials has effectively described the properties of the III-nitride nanotubes. Nanomechanics of boron-, aluminum-, and gallium-nitride nanotubes under the compression loading has been investigated and their Young's moduli were calculated.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.07a
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• pp.29-30
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• 2005

Experimental results are presented for the degradation of 3 nm-thick gate oxide ($SiO_2$) under both Negative-bias Temperature Instability(NBTI) and Hot-carrier-induced(HCI) stresses using P and NMOSFETs that are annealed with hydrogen or deuterium gas at high-pressure (1~5 atm.). Statistical parameter variations depend on the stress conditions. We suggest that deuterium bonds in $SiO_2$ film is effective in suppressing the generation of traps related to the energetic hot electrons.

• Journal of the Korea Fashion and Costume Design Association
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• v.4 no.1
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• pp.143-153
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• 2002

Fashion has been analyzed and explained in diverse ways. Fashion, like every phase of culture, is a reflection of the Zeitgeist. In order to understand the changing fashion we must understand the changing society. For fashion of a period are expressions of the interrelation of the various elements of the culture, including the social and political values, the economic and industrial progress, art, the development of technology, etc... Particularly fashion is closely connected with a style of art. In a style of art, futurism focused on the "dynamism" resulting from super-speed and high-technology. This study aimed to review literatures, fashion magazines, web-site in order to know how the dynamism of futurism is expressed in modern fashion. The results of this study were as follows; 1. Dynamism was expressed by means of lines, colors, patterns through the eyesights visually. Asymmetrical oblique lines, zig-zag lines or bold cutting expressed the mechanical and offensive dynamism. In contrast, such lines as curves and spirals expressed the soft and natural dynamism. Primary colors or complementary contrast expressed energetic and rhythmical dynamism. The geometrical patterns and automobile wheels patterns expressed dynamism resulting from mechanical aesthetics. 2. Dynamism was expressed through repeat of lines, colors, patterns, and textiles. Particularly Vinyl material, fluorescent material, metallic material, beads, and spangle expressed a strong dynamism. On the other hand, natural materials, paper and other similar ones are used to signify the orientation towards a futuristic high-technology society.y society.

• Journal of the Korea Institute of Military Science and Technology
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• v.15 no.5
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• pp.550-556
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• 2012

In this study, a series of ballistic experiments have been performed to investigate the protection mechanism of some inert reactive cassettes against shaped charge jet. Three kinds of material were tested as a core material of the inert cassettes, i.e. one of rubber materials, a high modulus and high strength composite material used for ballistic protection and a mixture of energetic materials. Parameters such as deformation of the cassettes, occurrence time of jet distortion, leading jet length and residual penetration depth were investigated from the experiments and they were compared to each other quantitatively according to the jet incidence angles. The results show that the increment of cassette deformation caused jet distortion to occur early and jet distortion brought decrease of the length of leading jet. Then the decrease of the length of leading jet accompanied the decrease of residual penetration depth.

• Bulletin of the Korean Space Science Society
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• 2011.04a
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• pp.20.2-20.2
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• 2011

The NASA Antarctica balloon experiment CREAM has successfully collected the data of energetic cosmic rays during flights in past years. We will present the recent analysis results of the CREAM experiment. We will also report on the launch and recovery process of the latest flight. The silicon charge detector of the CREAM has played the key role in the precision measurement of the charge constitution of energetic cosmic rays. We proposed the upgrade of the CREAM experiment with the installment of a new large silicon charge detector on top of the CREAM instrument. The charge measurement of the large silicon detector with no material in front is expected to improve the accuracy of the CREAM charge measurement drastically when combined with the measurement of the existing double layer silicon detector. We will present the fabrication of the large silicon detector and its performance in the radiation source test as well as in the beam test.

• Journal of the Korean Society of Propulsion Engineers
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• v.20 no.5
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• pp.19-30
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• 2016

We presented a hydrodynamic modeling necessary to accurately reproduce shock-induced detonation of pyrotechnic initiator. The methodology for such numerical prediction of shock propagation is quite straight forward if the models are properly implemented and solved in a well-formulated shock physics code. A series of SSGT(Small Scale Gap Test) and detailed hydrodynamic simulation are conducted to quantify the shock sensitivity of an acceptor that contains 97.5% RDX. A TBI(Through Bulkhead Initiator) system, consisting of a train configuration of Donor(HNS+HMX) - Bulkhead(STS) - Acceptor(RDX), were investigated to further validate the interaction between energetic and non-reactive materials for predicting the detonating response for successful operation of such small pyro device.

• Bulletin of the Korean Chemical Society
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• v.33 no.7
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• pp.2352-2358
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• 2012

A high-nitrogen energetic salt, 1-amino-1-hydrazino-2,2-dinitroethylene guanidine salt [G(AHDNE)], was synthesized by reacting of 1-amino-1-hydrazino-2,2-dinitroethylene (AHDNE) and guanidine hydrochloride in sodium hydroxide aqueous solution. The theoretical investigation on G(AHDNE) was carried out by B3LYP/$6-311+G^*$ method. The thermal behaviors of G(AHDNE) were studied with DSC and TG-DTG methods, and the result presents an intense exothermic decomposition process. The enthalpy, apparent activation energy and pre-exponential constant of the process are $-1060J\;g^{-1}$, $148.7kJ\;mol^{-1}$ and $10^{15.90}s^{-1}$, respectively. The critical temperature of thermal explosion of G(AHDNE) is $152.63^{\circ}C$. The specific heat capacity of G(AHDNE) was studied with micro-DSC method and theoretical calculation method, and the molar heat capacity is $314.69J\;mol^{-1}K^{-1}$ at 298.15 K. Adiabatic time-to-explosion of G(AHDNE) was calculated to be a certain value between 60-72 s. The detonation velocity and detonation pressure were also estimated. G(AHDNE) presents good performances.

• Journal of the Korean Ceramic Society
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• v.51 no.5
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• pp.511-515
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• 2014

The thermodynamic instability of bubbles in wet-foam colloidal suspension is due to the substantial area of their gas/liquid interface. Several physical processes lead to gas diffusion from smaller to larger bubbles, resulting in a coarsening and Ostwald ripening of wet foam. This includes a narrowing of the bubble size distribution. The distribution and microstructure of porous ceramics, the adsorption free energy and Laplace pressure of $Al_2O_3$ particle-stabilized colloidal suspension, and $SiO_2$ content were investigated for tailoring the bubble size. Wet-foam stability of more than 80% is related to the degree of hydrophobicity with contact angles of $62-70^{\circ}$ achieved from the surfactant. The contact angle replaces part of the highly energetic interface and lowers the free energy of the system. This leads to an apparent increase in the surface tension (26-33 mN/m) of the colloidal suspension.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.17 no.10
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• pp.1049-1055
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• 2004

Chemical Mechanical Polishing (CMP) is referred to as a three body tribological system, because it includes two solids in relative motion and the CMP slurry. On the assumption that the abrasives between the pad and the wafer could be a major reason not only for the friction force but also for material removal during polishing, the friction force generated during CMP process was investigated with the change of abrasive size and concentration of CMP slurry. The threshold point of average coefficient of friction (COF) with increase in abrasives concentration during interlayer dielectric (ILD) CMP was found experimentally and verified mathematically based on contact mechanics. The predictable models, Mode I (wafer is in contact with abrasives and pad) and Mode II (wafer is in contact with abrasives only), were proposed and used to explain the threshold point. The average COF value increased in the low abrasives concentration region which might be explained by Mode I. In contrast the average COF value decreased at high abrasives concentration which might be regarded to as Mode II. The threshold point observed seemed to be due to the transition from Mode I to Mode II. The tendency of threshold point with the variation of abrasive size was studied. The increase of particle radius could cause contact status to reach transition area faster. The correlation between COF and material removal rate was also investigated from the tribological and energetic point of view. Due to the energy loss by vibration of polishing equipment, COF value is not proportional to the material removal rate in this experiment.