In large enterprises subject to constant employee turnover and challenging security policies, the administration of Role-based Access Control (RBAC) is a daunting task that is often highly centralized in a small team of security administrators. The aim of this work is to determine why existing models for Administrative Role-based Access Control (ARBAC) have failed to achieve success and thus mo...

Please cite this article in press as: R. Zhang et doi:10.1016/j.adhoc.2010.08.012 Video streaming over wireless links is a challenging issue due to the stringent Qualityof-Service (QoS) requirements of video traffic, the limited wireless channel bandwidth and the broadcast nature of wireless medium. As contention-based or reservation-based (i.e., contention-free) medium access control (MAC) pro...

Today more and more media data is produced completely in the digital domain without the need of analogue input. This brings an increase of flexibility and efficiency in media handling, as distributed access, duplication and modification are possible without the need to move or touch physical data carriers. But this also reduces the security of the process: Without physical originals to refer to...

This paper includes a new technique for media access control (MAC) in the Ultra Wide Band (UWB) spectrum. We use a TDMA based protocol that utilizes Multiband Impulse-based Ultra Wideband (MI-UWB). The proposed MAC protocol (UWB-MAC) uses TDMA on multiple bands to maximize throughput for streaming media applications. This is accomplished by using MI-UWB in combination with TDMA on multiple chan...

Part I Social Media Content Analysis Quantifying Visual-Representativeness of Social Image Tags Using Image Tag Clarity . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 Aixin Sun and Sourav S. Bhowmick Tag-Based Social Image Search: Toward Relevant and Diverse Results . . 25 Kuiyuan Yang, Meng Wang, Xian-Sheng Hua, and Hong-Jiang Zhang Social Image Tag Ranking by Two-View Learning . . ...

We develop a new Media Access Control strategy, called Plane Cover Multiple Access (PCMA), that provides a means of allocating wireless bandwidth in a packet based cellular system. PCMA seeks to maximize the number of parallel transmissions among cells by defining virtual cells in which users transmit using a given reuse factor. By keeping the reuse factors low, system throughput can be maximiz...

IPTV video services are under development for managed broadband networks, with ’last-mile’ delivery across wireless, ADSL or cable access networks. Delivering multiple video streams over a constrained channel often requires bitrate transcoders for bandwidth adaptation. This paper presents a bandwidth allocation scheme based on content complexity to equalize the overall video quality, in effect ...