Multicast delivery based on unicast and subnet multicast

In spite of the numerous works previously made, IP multicasting has not been widely deployed in the public Internet. We present a realistic alternative scheme for IP multicasting, which is based on the unicast transport from a remote sender to a local subnet and the multicast forwarding to receivers within the subnet     

Demonstration of a 20 W class high-temperature polymer electrolyte fuel cell stack with novel fabrication of a membrane electrode assembly

Acid-doped polybenzimidazole (PBI) membrane and polytetrafluoroethylene (PTFE)-based electrodes are used for the membrane electrode assembly (MEA) in high-temperature polymer electrolyte fuel cells (HTPEFCs). To find the optimum PTFE content for the catalyst layer, the PTFE ratio in the electrodes is varied from 25 to 50 wt%. To improve the performance of the electrodes, PBI is added to the catalyst layer. With a weight ratio of PTFE to Pt/C of 45:55 (45 wt% PTFE in the catalyst layer), the fuel cell shows good performance at 150 °C under non-humidified conditions. When 5 wt% PBI is added to the electrodes, performance is further improved (250 mA cm⁻² at 0.6 V). Our 20 W class HTPEFC stack is fabricated with a novel MEA. This MEA consists of 8 layers (1 phosphoric acid-doped PBI membrane, 2 electrodes, 1 sub-gasket, 2 gas-diffusion media, 2 gas-sealing gaskets). The sub-gasket mitigates the destruction of a highly acid-doped PBI membrane and provides long-term durability to the fuel cell stack. The stack operates for 1200 h without noticeable cell degradation.     

Time‐Slotted Scheduling Schemes for Multi‐hop Concurrent Transmission in WPANs with Directional Antenna

To achieve high‐speed (giga‐bit) connectivity for short‐range wireless multimedia applications, the millimeter‐wave (mmWave) wireless personal area networks with directional antennas are gaining increased interest. Due to the use of directional antennas and mmWave communications, the probability of non‐interfering transmissions increases in a localized region. Network throughput can be increased immensely by the concurrent time allocation of non‐interfering transmissions. The problem of finding optimum time allocation for concurrent transmissions is an NP‐hard problem. In this paper, we propose two enhanced versions of previously proposed multi‐hop concurrent transmission (MHCT) schemes. To increase network capacity, the proposed schemes efficiently make use of the free holes in the time‐allocation map of the MHCT scheme; thus, making it more compact.     

Performance Evaluation of an XML‐Based Conference Control Protocol for Centralized VoIP Conference

For communication between heterogeneous conference systems, it is important to build a conference control protocol independent from signaling protocols. We simulate an XML‐based conference control that is under consideration as a standard mechanism. We describe the framework and operations for easy implementation in heterogeneous conference systems. The simulation results show that the proposed control protocol provides a consistent service for an increasing number of conferences and participants in small to mid‐size centralized conferencing.     

The 185delAG BRCA1 mutation originated before the dispersion of Jews in the diaspora and is not limited to Ashkenazim

The 185delAG mutation in BRCA1 is detected in Ashkenazi Jews both in familial breast and ovarian cancer and in the general population. All tested Ashkenazi mutation carriers share the same allelic pattern at the BRCA1 locus. Our previous study showed that this 'Ashkenazi' mutation also occurs in Iraqi Jews with a similar allelic pattern. We extended our analysis to other non-Ashkenazi subsets: 354 of Moroccan origin, 200 Yemenites and 150 Iranian Jews. Heteroduplex analysis complemented by direct DNA sequencing of abnormally migrating bands were employed. Four of Moroccan origin (1. 1%) and none of the Yemenites or Iranians was a carrier of the 185delAG mutation. BRCA1 allelic patterns were determined for four of these individuals and for 12 additional non-Ashkenazi 185delAG mutation carriers who had breast/ovarian cancer. Six non-Ashkenazi individuals shared the common 'Ashkenazi haplotype', four had a closely related pattern, and the rest ( n = 6) displayed a distinct BRCA1 allelic pattern. We conclude that the 185delAG BRCA1 mutation occurs in some non-Ashkenazi populations at rates comparable with that of Ashkenazim. The majority of Jewish 185delAG mutation carriers have a common allelic pattern, supporting the founder effect notion, but dating the mutation's origin to an earlier date than currently estimated. However, the different allelic pattern at the BRCA1 locus even in some Jewish mutation carriers, might suggest that the mutation arose independently.     

Hydrodynamic effects in water media in electric and magnetic fields

Journal of Engineering Physics and Thermophysics -