• The Science & Technology
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• v.17 no.8 s.183
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• pp.45-47
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• 1984

고분자 휘스커 (Polymer-Whisker) / 초밀비자 (Submicron Particles) / 레이저광선이용 피혁재단 / 프랑스 특유의 컴퓨터 언어개발

• 한국초전도학회:학술대회논문집
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• v.15
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• pp.31-31
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• 2005

• Korean Journal of Materials Research
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• v.2 no.6
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• pp.461-467
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• 1992

A fabrication process for SiC whisker preform reinforced AC4A Al composites is being developed. The Al alloy used as the matrix in this study is AC4A. SiC whisker preform made by Tokai Carbon Co. Ltd. Shizuoka, Japan were used. These consisted of $\beta$-type single crystals 0.1 ~ 10${\mu}$m in diameter and 20~10${\mu}$m in length. The most adequate fabrication condition was that whisker preform was preheated up to 750~80$0^{\circ}C$, set into a mould preheated to ~40$0^{\circ}C$, molten Al alloy heated to ~80$0^{\circ}C$ and applied pressure 75MPa. And Si$C_w$reinforced AC4A composite was advanced above twice than AC4AI/M. Also it was not large effect by pressure at Si$C_w$ 20v/o.

• Journal of the Microelectronics and Packaging Society
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• v.12 no.1 s.34
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• pp.65-71
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• 2005

At present, Electronic industries push ahead to eliminate the Pb(Lead) -a hazardous material-from all products. Especially, we have performed to select the optimum standard composition of lead free alloy for the application to products for about 3 years from 2000. These days, we have the chance for applying to the mass-production. This project constructed the system for applying the lead free solders on consumer electronic products, which is one of the major products of the LG Electronics. To select the lead free solders with corresponding to the product features, we have passed through the test and applied with Sn-3.0Ag-0.5Cu alloy system to our products, and for the application to the high melting temperature composition, we secured the thermal resistance of the many parts and substrate and optimized the processing conditions. We have operated the temperature cycling test and the high temperature storage test under the standards to confirm the reliability of the products. On these samples, we considered the consequence of our decision by the operating test. For the long life time of the product, we have operated the temperature cycling test at $-45^{\circ}C\;-\;+125^{\circ}C$, 1 cycle/hour, 1000 cycles. Also we have tested the tin whisker growth about lead free plating on lead finish. We have analyzed with the SEM, EDS and any other equipment for confirming the failure mode at the joint and the tin whisker growth on lead free finish.

• Applied Chemistry for Engineering
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• v.8 no.3
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• pp.446-453
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• 1997

The initial product was prepared by heating for 3 hrs at $1000^{\circ}C$ using a mixture of the rutile sand and industral $K_2CO_3$ in the molar ratio 2.0. And the intermediate product, fibrous potassium tetratitanate of layer structure, was obtained by the boiling water treatment of 10hrs for initial product using the calcination method. Also $KHTi_4O_9{\cdot}1.1H_2O$ was synthesized by ion exchange reaction through the acid treatment for 30 min at 0.005M HCl solution and then $K_2Ti_8O_{17}$ whisker of $length=10{\mu}m$, $diameter=0.2{\mu}m$ was synthesized by heat treatment at temperature range of $400{\sim}600^{\circ}C$.

• Applied Chemistry for Engineering
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• v.7 no.6
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• pp.1174-1180
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• 1996

Potassium hexatitanate whisker was effectively prepared with calcination and flux method by using industrial $TiO_2$, $K_2CO_3$ and $K_2MoO_4$ as the starting materials. When it was synthesized by the calcination method, the filtrate after boiling water treatment was required a neutralization, as the pH of filtrate was higher than 9. Because K component was very small, recovery of K component was not economically suitable. In case of flux method, flux was recovered 96.1% of Mo component and 91.8% of K component at $K_2MoO_4$, for 10th treatment in boiling water of 100ml to 10g.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.14 no.4
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• pp.97-110
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• 2004

As modem web services become enormously complex, web attacks has become frequent and serious. Existing security solutions such as firewalls or signature-based intrusion detection systems are generally inadequate in securing web services, and analysis of raw web log data is simply impractical for most organizations. Visual display of "interpreted" web logs, with emphasis on anomalous web requests, is essential for an organization to efficiently track web usage patterns and detect possible web attacks. In this paper, we discuss various issues related to effective real-time visualization of web usage patterns and anomalies. We implemented a software tool named SAD (session anomaly detection) Viewer to satisfy such need and conducted an empirical study in which anomalous web traffics such as Misuse attacks, DoS attacks, Code-Red worms and Whisker scans were injected. Our study confirms that SAD Viewer is useful in assisting web security engineers to monitor web usage patterns in general and anomalous web sessions in particular.articular.

• Applied Chemistry for Engineering
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• v.9 no.2
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• pp.193-199
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• 1998

The mixtures of ultra-high molecular weight polythylene (UHMWPE), high density polyethylene (HDPE), process oil (mineral oil) and potassium hexatitanate whisker were melted and mixed at $150^{\circ}C$ for 30min, and prepared by compression molding to the specimen of separator of about $200{\mu}m$ thickness at the same temperature and 5000 psi. Thereafter the pores were formed by extracting process oil with organic solvents. In this study, the range of PR (the ratio polymer to process oil) was varied from 0.1 to 0.5 because the specimen turned into rubbery phase at which PR was below 0.1 whereas it changed into gel phase at which PR was above 0.5. When the specimen was treated with nonpolar organic solvents, process oil was extracted nearly 98%. Tensile strength was $31kg/cm^2$ at PR = 0.426, and resistance of specimen was $37m{\Omega}/cm^2$ at PR = 0.186, and $53m{\Omega}/cm^2$ at PR = 0.426. The $N_2$ adsorption-desorption isotherm showed a hysteresis representing regions of capillary condensation, and the surface area at PR = 0.186 was relatively large as $130cm^2/g$. Potassium hexatitanate whisker was randomly dispersed in between PE layers. It might be that the whisker is intercalated through the PE thin layers oriented by compression.

• Proceedings of the Korean Ceranic Society Conference
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• 2003.04a
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• pp.212.1-212
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• 2003

• Journal of Welding and Joining
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• v.20 no.4
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• pp.451-458
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• 2002

플라즈마 용사법에 의한 섬유강화 복합 소재를 개발하면서 독특한 미세구조가 발견되었다. 이러한 형상은 코팅의 물리적 특성과 직접적으로 관련이 있다고 사료된다 섬유강화 코팅의 구조를 밝히기 위해 고배율 전자현미경이 사용되었으며 분석을 통해 일반적 용사코팅 의 미세구조가 내부에 투입된 강화 섬유(FIBER 또는 WHISKER)에 의해 변형되며 열적으로 anisotropic한 상태로 되었음을 보여주었다.