41,442 research outputs found
Energy-aware peering routing protocol for indoor hospital body area network communication
The recent research in Body Area Networks (BAN) is focused on making its communication more reliable, energy efficient, secure, and to better utilize system resources. In this paper we propose a novel BAN network architecture for indoor hospital environments, and a new mechanism of peer discovery with routing table construction that helps to reduce network traffic load, energy consumption, and improves BAN reliability. We have performed extensive simulations in the Castalia simulation environment to show that our proposed protocol has better performance in terms of reduced BAN traffic load, increased number of successful packets received by nodes, reduced number of packets forwarded by intermediate nodes, and overall lower energy consumption compared to other protocols
Bullying Roles in Changing Contexts: The Stability of Victim and Bully Roles from Primary to Secondary School
The present study was conducted to predict bullying roles over a six years time period and across contexts differing in the degree of peer hierarchies. Out of two representative data sets from primary (N = 1525) and secondary school (N = 2958), 282 children (156 boys; 126 girls) were followed up longitudinally. Self reports on bullying experiences and peer reports about social status were assessed by a structured individual interview (in primary school) and by questionnaire given classwise (in secondary school). Risk analyses showed, that only a bully role in primary school yields a risk to be sustained in secondary school. However, victims in primary school classes with a more pronounced degree of hierarchical structuring proved stable in their role while the victim role was unstable from primary school classes with low hierarchical structuring. This interaction did not apply to bully role stability. Differential characteristics of the victim and the bully role in primary school and secondary school settings are discussed.Die vorliegende Untersuchung wurde durchgefßhrt, um Bullyingrollen ßber einen Zeitraum von sechs Jahren und Kontexte, die sich im Ausmaà der sozialen Strukturierung unterschieden, vorherzusagen. Auf der Grundlage von zwei repräsentativen Datensätzen aus der Grundschule (n= 1525) und der weiterfßhrenden Schule (N= 2958) wurden dazu die Daten von 282 Kinder (156 Jungen, 126 Mädchen) längsschnittlich analysiert. Die Selbstberichte ßber Bullyingerfahrungen und Mitschßlerberichte ßber den sozialen Status der Kinder wurden in der Grundschule durch ein strukturiertes Interview und in der weiterfßhrenden Schule durch klassenweise Fragebogenerhebung erfasst. Riskikoanalysen zeigen, dass nur die Täterrolle in der Grundschule einen Risikofaktor fßr eine Täterrolle in der weiterfßhrenden Schule darstellt. Eine Opferrolle war hingegen nur dann stabil, wenn die Opfer in Grundschulklassen mit schon ausgeprägten Dominanzstrukturen viktimisiert wurden, während aus Grundschulklassen mit geringer hierarchischer Strukturierung keine stabile Opferrolle vorhersagbar war. Dieses Interaktionmuster gilt nicht fßr die Stabilität der Täterrollen. Differentielle Charakteristika der Opferrolle und der Täterrolle in der Grundschule und der weiterfßhrenden Schule werden diskutiert
Considering Teaching Excellence in Higher Education: 2007-2013: A Literature Review Since the CHERI Report 2007
No abstract available
A Taxonomy of Data Grids for Distributed Data Sharing, Management and Processing
Data Grids have been adopted as the platform for scientific communities that
need to share, access, transport, process and manage large data collections
distributed worldwide. They combine high-end computing technologies with
high-performance networking and wide-area storage management techniques. In
this paper, we discuss the key concepts behind Data Grids and compare them with
other data sharing and distribution paradigms such as content delivery
networks, peer-to-peer networks and distributed databases. We then provide
comprehensive taxonomies that cover various aspects of architecture, data
transportation, data replication and resource allocation and scheduling.
Finally, we map the proposed taxonomy to various Data Grid systems not only to
validate the taxonomy but also to identify areas for future exploration.
Through this taxonomy, we aim to categorise existing systems to better
understand their goals and their methodology. This would help evaluate their
applicability for solving similar problems. This taxonomy also provides a "gap
analysis" of this area through which researchers can potentially identify new
issues for investigation. Finally, we hope that the proposed taxonomy and
mapping also helps to provide an easy way for new practitioners to understand
this complex area of research.Comment: 46 pages, 16 figures, Technical Repor
A Random Structure for Optimum Cache Size Distributed hash table (DHT) Peer-to-Peer design
We propose a new and easily-realizable distributed hash table (DHT)
peer-to-peer structure, incorporating a random caching strategy that allows for
{\em polylogarithmic search time} while having only a {\em constant cache}
size. We also show that a very large class of deterministic caching strategies,
which covers almost all previously proposed DHT systems, can not achieve
polylog search time with constant cache size. In general, the new scheme is the
first known DHT structure with the following highly-desired properties: (a)
Random caching strategy with constant cache size; (b) Average search time of
; (c) Guaranteed search time of ; (d) Truly local
cache dynamics with constant overhead for node deletions and additions; (e)
Self-organization from any initial network state towards the desired structure;
and (f) Allows a seamless means for various trade-offs, e.g., search speed or
anonymity at the expense of larger cache size.Comment: 13 pages, 2 figures, preprint versio
Can filesharers be triggered by economic incentives? Results of an experiment
Illegal filesharing on the internet leads to considerable financial losses for artists and copyright owners as well as producers and sellers of music. Thus far, measures to contain this phenomenon have been rather restrictive. However, there are still a considerable number of illegal systems, and users are able to decide quite freely between legal and illegal downloads because the latter are still difficult to sanction. Recent economic approaches account for the improved bargaining position of users. They are based on the idea of revenue-splitting between professional sellers and peers. In order to test such an innovative business model, the study reported in this article carried out an experiment with 100 undergraduate students, forming five small peer-to-peer networks.The networks were confronted with different economic conditions.The results indicate that even experienced filesharers hold favourable attitudes towards revenue-splitting.They seem to be willing to adjust their behaviour to different economic conditions
An Overview of Mobile Ad Hoc Networks for the Existing Protocols and Applications
Mobile Ad Hoc Network (MANET) is a collection of two or more devices or nodes
or terminals with wireless communications and networking capability that
communicate with each other without the aid of any centralized administrator
also the wireless nodes that can dynamically form a network to exchange
information without using any existing fixed network infrastructure. And it's
an autonomous system in which mobile hosts connected by wireless links are free
to be dynamically and some time act as routers at the same time, and we discuss
in this paper the distinct characteristics of traditional wired networks,
including network configuration may change at any time, there is no direction
or limit the movement and so on, and thus needed a new optional path Agreement
(Routing Protocol) to identify nodes for these actions communicate with each
other path, An ideal choice way the agreement should not only be able to find
the right path, and the Ad Hoc Network must be able to adapt to changing
network of this type at any time. and we talk in details in this paper all the
information of Mobile Ad Hoc Network which include the History of ad hoc,
wireless ad hoc, wireless mobile approaches and types of mobile ad Hoc
networks, and then we present more than 13 types of the routing Ad Hoc Networks
protocols have been proposed. In this paper, the more representative of routing
protocols, analysis of individual characteristics and advantages and
disadvantages to collate and compare, and present the all applications or the
Possible Service of Ad Hoc Networks.Comment: 24 Pages, JGraph-Hoc Journa
Interactive Visual Analysis of Networked Systems: Workflows for Two Industrial Domains
We report on a first study of interactive visual analysis of networked systems. Working with ABB Corporate Research and Ericsson Research, we have created workflows which demonstrate the potential of visualization in the domains of industrial automation and telecommunications. By a workflow in this context, we mean a sequence of visualizations and the actions for generating them. Visualizations can be any images that represent properties of the data sets analyzed, and actions typically either change the selection of data visualized or change the visualization by choice of technique or change of parameters
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