Time filter

Source Type

Keizan, South Korea

Kang K.-S.,Kyungil University
Industrial and Engineering Chemistry Research | Year: 2012

The surface of silica spheres was modified using 3-mercaptopropyl trimethoxysilane (MPTMS) with an acid catalyst and a base catalyst. Large aggregation was observed for the spheres modified with an acid catalyst. The spheres modified with an acid catalyst (ACS) show aggregated spheres. However, no aggregation was observed for the spheres modified with a base catalyst (BCS). Aqueous lead solutions with 625 and 1663 ppm were used to test the removal of lead ions. Various amounts of modified spheres were treated to the lead solutions. The lead concentration drastically decreased with the increase of the amount of the spheres. The lead removal efficiency for the BCS is much more effective than that of ACS. For more-quantitative analysis of the residual lead concentration, inductive coupled plasma-mass spectrometry (ICP-MS) was employed. As the amount of spheres increased, the lead concentration drastically decreased. The lowest concentration of 1.2 ppb was obtained, which indicates that the lead ion can be completely removed from the aqueous system. © 2012 American Chemical Society. Source

Kim H.,Kyungil University
International Journal of Security and its Applications | Year: 2013

Radio Frequency Identification (RFID) tags, due to their ability to uniquely identify every individual item and low cost, are well suited for supply chain management and are expected to replace barcodes in the near future. However, unlike barcodes, these tags have a longer range in which they are allowed to be scanned, subjecting them to unauthorized scanning by malicious readers and to various other attacks, including cloning attacks. Privacy and security concerns inhibit the fast adaption of RFID technology for many applications. A number of authentication protocols that address these concerns have been proposed but real-world solutions that are secure and maintain low communication cost are still needed and being investigated. Recently, Cho et al. proposed a hash-based RFID mutual authentication protocol using a secret value. However, this paper shows that Cho et al.'s protocol is weak against desynchronization attack and proposes a remedy mutual authentication protocol, which offers a high level of security based on hash operation with synchronized secret. The protocol is applicable to resource, power and computationally constraint platforms such as RFID tags. Our investigation shows that it can provide mutual authentication and untraceability as well as resistance to replay, denial-of-service and man-in-the-middle attacks, while retaining a competitive computation cost. Source

The formation of N2O in NH3-SCR deNOx reaction over an on-site-used commercial V2O5-WO 3/TiO2 catalyst has been measured using an on-line IR system with a modified gas cell. The N2O could be formed by the SCR and NH3 oxidation reactions. These two reactions were particularly enhanced with the on-site-used sample. © 2010 Springer Science+Business Media, LLC. Source

Hur S.H.,University of Ulsan | Park J.-N.,Kyungil University
Asia-Pacific Journal of Chemical Engineering | Year: 2013

Graphene is considered a promising material for fuel cell vehicles because of its excellent chemical, mechanical, and electrical properties. Recent studies have revealed that using graphene or modified graphene as the catalyst support or as a metal-free catalyst results in significant improvement in the electrocatalytic activity, long term durability, and CO tolerance. This article summarizes both the recent progress of graphene-based fuel cell research and current developments in graphene fabrication processes such as mechanical exfoliation, chemical vapor deposition, and chemical exfoliation. The roles of graphene are also discussed by introducing mechanisms on the basis of theoretical calculations as well as experimental analysis. © 2012 Curtin University of Technology and John Wiley & Sons, Ltd. Source

Kim H.,Kyungil University
International Journal of Security and its Applications | Year: 2014

Recent Federal Communications Commission rules promise a whole new set of possible applications, which allow unlicensed use on a secondary basis of the Television White Spaces (TVWS), called as cognitive radio technology. ECMA-International launched the first step towards realizing these applications by creating and adopting industry standards. This paper reviews the first industrial standards for personal/portable devices in the TVWS from ECMA-International focused on the security aspects. After that, we point out the lack of security facilities in the standard, which does support the link-to-link security but not for the end-to-end security, and then propose two location-based authentication protocols to cope up with the deficiencies over cognitive radio networks. We use location information as thesecurecredentialfor the authentications. The protocols can be support privacy issues of consumer premise equipments and integrated into the extensible authentication protocol. © 2014 SERSC. Source

Discover hidden collaborations