Sung-Jae Cho

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Despite the popularity of VoIP these clays, this method of communication may present significant security challenges in terms of privacy and accounting. Authentication and message encryption are considered essential mechanisms in VoIP for it to be comparable to PSTN. SIP is responsible for setting up a secure call in VoIP. SIP employs TLS, DTLS or IPSec,(More)
Using a macroscopic ensemble of highly enriched (6,5) single-wall carbon nanotubes, combined with high signal-to-noise ratio and time-dependent differential transmission spectroscopy, we have generated vibrational modes in an ultrawide spectral range (10-3000 cm(-1)). A total of 14 modes were clearly resolved and identified, including fundamental modes of(More)
Wireless local area networks (WLAN) promise to be widely deployed in a short time, because they provide wire free connections with ease and with much higher transmission rates than current cellular systems. However, security holes have been identified in the operation of WLANs. The 802.11i protocol has been announced to protect the WLAN application area.(More)
The crystal structure of Escherichia coli rhamnose mutarotase (YiiL) is completely different from the previously reported structures of the Lactococcus lactis galactose mutarotase and the Bacillus subtilis RbsD (pyranase). YiiL exists as a locally asymmetric dimer, which is stabilized by an intermolecular beta-sheet, various hydrophobic interactions, and a(More)
Human cells contain two homologs of the yeast RAD23 protein, hHR23A and hHR23B, which participate in the DNA repair process. hHR23B houses a domain (residues 277-332, called XPCB) that binds specifically and directly to the xeroderma pigmentosum group C protein (XPC) to initiate nucleotide excision repair (NER). This domain shares sequence homology with a(More)
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