http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Secrecy Rate for MISO Rayleigh Fading Channels with Relative Distance of Eavesdropper
Namseok Chang,Chan-Byoung Chae,Jeongseok Ha,Joonhyuk Kang IEEE 2012 IEEE COMMUNICATIONS LETTERS Vol.16 No.9
<P>In this letter, we extend the results of secure transmission with artificial noise over multiple-input single-output (MISO) wiretap channels. There is a case such that the transmitter knows the relative distance of the eavesdropper. That is, it knows the distance from itself to the eavesdropper divided by its distance to the legitimate receiver. The study found that when the transmitter utilizes information about the relative distance of the passive eavesdropper, the system can achieve a significant increase in its secrecy rate. This work may be useful evaluating a secure communication system in where a secure-zone is enforced and is accessible, exclusively, to the legitimate receiver.</P>
Sub-micrometer 크기의 패턴의 복제시 발생되는 이형 특성의 분석
이남석(Namseok Lee),강신일(Shinill Kang) 대한기계학회 2003 대한기계학회 춘추학술대회 Vol.2003 No.4
With the increasing demand for plastic micro components, micro-/nano-molding using the mother stamper<br/> has received much attention. If the replication temperature is too high, the adhesion between the stamper<br/> and the polymer melt may deteriorate the surface quality of the replicated part, excessively wearing down the<br/> stamper. In this paper, an experimental method analyzes the temperature dependency of the anti-adhesion<br/> property between the actual stamper with patterns of sub-micrometer and the polymer melt. As a practical<br/> example, a correlation between the contact angle of the stamper and the surface quality of the molded<br/> substrates as a function of the replication temperature, respectively, was obtained quantitatively.
최성우(Sungwoo Choi),이남석(Namseok Lee),강신일(Shinill Kang) 대한기계학회 2003 대한기계학회 춘추학술대회 Vol.2003 No.11
In this study, application of SAM (self-assembled monolayer) to nano replication process as an anti-adhesion layer was presented to reduce the surface energy between the nano stamper and the replicated polymeric nano patterns. To analyze wettability and adhesion force of SAM, contact angle and LFM (Lateral Force Microscopy) were measured at the actual processing temperature for the case of nano compression molding. It was found that the surface energy due to SAM deposition on the nickel nano stamper markedly decreased and the quality of SAM on the nickel stamper maintained under the actual molding environments. Additionally, an experimental method is presented to analyze the temperature dependency of the anti-adhesion property between the nano stamper and the polymer. As a practical example, a correlation between the contact angle of the stamper and the surface quality of the molded substrates as a function of the replication temperature, respectively, was obtained quantitatively. Finally, polymeric nano patterns were replicated using nano replication processes with SAM deposited metallic nano stamper. Measurement of the surface profiles and the surface roughness of the replicated polymeric nano patterns showed the usefulness of the SAM as an anti-adhesion layer in nano molding processes.
JinBae Kim,Sang-Geun Cho,Namseok Kang,Kwangyeol Choi,Jongryoul Kim IEEE 2012 IEEE transactions on magnetics Vol.48 No.11
<P>We present the results of the magnetic domain structures of BaAl<SUB>2</SUB>Fe<SUB>10</SUB>O<SUB>19</SUB> nanopowders prepared by a self-propagating combustion process. Amorphous precursors were calcined at 850 °C for 2 h with NaCl (Sample I) and without NaCl (Sample II). The transmission electron microscope and atomic force microscopy images evidently suggested that there was a topological difference between Sample I (plate- and rod-shaped nanopowders) and Sample II (rod-shaped nanoparticles). We observed a considerably enhanced coercivity in Sample II, compared to Sample I. This result can be understood by the change in the magnetic domain width due to the shape effect of the nanopowders, which was investigated by measuring the field-controlled magnetic force microscopy.</P>
Minseok Choi,Jung Mo Yang,Jiseok Lim,Namseok Lee,Shinill Kang IEEE 2009 IEEE transactions on magnetics Vol.45 No.5
<P>In this research, the effect of lift height of magnetic force microscopy (MFM) tip on the resolution of the magnetic force microscopy images of the magnetic pillar patterns, having diameter of 50 nm, pitch of 100 nm, and height of 35 nm was analyzed experimentally. A patterned substrate for patterned magnetic media was fabricated by an UV nanoimprinting process with a silicon nanostamp. The silicon nanostamp was fabricated by electron-beam lithography and inductively coupled plasma etching process. We deposited magnetic layers on the nanoimprinted pillar patterns to make the perpendicular patterned magnetic media with isolated magnetic domains. The magneto-optic Kerr effect analysis was carried out to evaluate the magnetic properties of the deposited magnetic layer. To analyze the effect of lift height of MFM tip on the resolution of the MFM images of the isolated nano scale magnetic domains, MFM measurement was carried out with various MFM tip lift heights. Finally, the optimum lift height of the MFM tip was obtained as 35 nm for higher resolution of MFM images of the isolated magnetic domains.</P>