Approximate Bounds and Expressions for the Link Utilization of Shortest-Path Multicast Network Traffic

Multicast network traffic is information with one source node, but many destination nodes. Rather than setting up individual connections between the source node and each destination node, or broadcasting the information to the entire network, multicasting efficiently exploits link capacity by allowing the source node to transmit a small number of copies of the information to mutually-exclusive groups of destination nodes. Multicasting is an important topic in the fields of networking (video and audio conferencing, video on demand, local-area network interconnection) and computer architecture (cache coherency, multiprocessor message passing). In this paper, we derive approximate expressions for the minimum cost (in terms of link utilization) of shortestpath multicast traffic in arbitrary tree networks. Our results provide a theoretical best-case scenario for link utilization of multicast distribution in tree topologies overlaid onto arbitrary graphs. In real networks such as the Interne..

Integrating Security in the MAC Layer of WDM Optical Networks

We introduce a new technique for providing security in a broadcast-and-select, wavelengthdivision -multiplexed (WDM) optical network. The approach provides privacy of communications by employing a novel challenge-response scheme and exploiting the tuning delay inherent in optical receivers. The proposed technique can be integrated easily into any existing WDM media-accesscontrol (MAC) protocol that employs tunable receivers. The modified protocol would require every idle user, who is not scheduled to receive data, to tune in to a channel that does not contain sensitive data. A violation of the protocol can be detected with very high probability, and appropriate measures can be taken against the violator. The technique provides features that cannot be achieved with cryptography alone. Significant benefits of the proposed approach include the ability to detect security violations as they occur, and an efficient mechanism to provide privacy for multicast transmissions. We devel..

Top 100 cited articles in cardiovascular magnetic resonance: a bibliometric analysis

Background: With limited health care resources, bibliometric studies can help guide researchers and research funding agencies towards areas where reallocation or increase in research activity is warranted. Bibliometric analyses have been published in many specialties and sub-specialties but our literature search did not reveal a bibliometric analysis on Cardiovascular Magnetic Resonance (CMR). The main objective of the study was to identify the trends of the top 100 cited articles on CMR research. Methods: Web of Science (WOS) search was used to create a database of all English language scientific journals. This search was then cross-referenced with a similar search term query of Scopus® to identify articles that may have been missed on the initial search. Articles were ranked by citation count and screened by two independent reviewers. Results: Citations for the top 100 articles ranged from 178 to 1925 with a median of 319.5. Only 17 articles were cited more than 500 times, and the vast majority (n = 72) were cited between 200–499 times. More than half of the articles (n = 52) were from the United States of America, and more than one quarter (n = 21) from the United Kingdom. More than four fifth (n = 86) of the articles were published between the time period 2000–2014 with only 1 article published before 1990. Circulation and Journal of the American College of Cardiology made up more than half (n = 62) of the list. We found 10 authors who had greater than 5 publications in the list. Conclusion: Our study provides an insight on the characteristics and quality of the most highly cited CMR literature, and a list of the most influential references related to CMR.Medicine, Faculty ofNon UBCRadiology, Department ofReviewedFacult