694,369 research outputs found
Adjacency Matrix Based Energy Efficient Scheduling using S-MAC Protocol in Wireless Sensor Networks
Communication is the main motive in any Networks whether it is Wireless
Sensor Network, Ad-Hoc networks, Mobile Networks, Wired Networks, Local Area
Network, Metropolitan Area Network, Wireless Area Network etc, hence it must be
energy efficient. The main parameters for energy efficient communication are
maximizing network lifetime, saving energy at the different nodes, sending the
packets in minimum time delay, higher throughput etc. This paper focuses mainly
on the energy efficient communication with the help of Adjacency Matrix in the
Wireless Sensor Networks. The energy efficient scheduling can be done by
putting the idle node in to sleep node so energy at the idle node can be saved.
The proposed model in this paper first forms the adjacency matrix and
broadcasts the information about the total number of existing nodes with depths
to the other nodes in the same cluster from controller node. When every node
receives the node information about the other nodes for same cluster they
communicate based on the shortest depths and schedules the idle node in to
sleep mode for a specific time threshold so energy at the idle nodes can be
saved.Comment: 20 pages, 2 figures, 14 tables, 5 equations, International Journal of
Computer Networks & Communications (IJCNC),March 2012, Volume 4, No. 2, March
201
User data dissemination concepts for earth resources
Domestic data dissemination networks for earth-resources data in the 1985-1995 time frame were evaluated. The following topics were addressed: (1) earth-resources data sources and expected data volumes, (2) future user demand in terms of data volume and timeliness, (3) space-to-space and earth point-to-point transmission link requirements and implementation, (4) preprocessing requirements and implementation, (5) network costs, and (6) technological development to support this implementation. This study was parametric in that the data input (supply) was varied by a factor of about fifteen while the user request (demand) was varied by a factor of about nineteen. Correspondingly, the time from observation to delivery to the user was varied. This parametric evaluation was performed by a computer simulation that was based on network alternatives and resulted in preliminary transmission and preprocessing requirements. The earth-resource data sources considered were: shuttle sorties, synchronous satellites (e.g., SEOS), aircraft, and satellites in polar orbits
Route Planning in Transportation Networks
We survey recent advances in algorithms for route planning in transportation
networks. For road networks, we show that one can compute driving directions in
milliseconds or less even at continental scale. A variety of techniques provide
different trade-offs between preprocessing effort, space requirements, and
query time. Some algorithms can answer queries in a fraction of a microsecond,
while others can deal efficiently with real-time traffic. Journey planning on
public transportation systems, although conceptually similar, is a
significantly harder problem due to its inherent time-dependent and
multicriteria nature. Although exact algorithms are fast enough for interactive
queries on metropolitan transit systems, dealing with continent-sized instances
requires simplifications or heavy preprocessing. The multimodal route planning
problem, which seeks journeys combining schedule-based transportation (buses,
trains) with unrestricted modes (walking, driving), is even harder, relying on
approximate solutions even for metropolitan inputs.Comment: This is an updated version of the technical report MSR-TR-2014-4,
previously published by Microsoft Research. This work was mostly done while
the authors Daniel Delling, Andrew Goldberg, and Renato F. Werneck were at
Microsoft Research Silicon Valle
Performance evaluation of WMN-GA for different mutation and crossover rates considering number of covered users parameter
Node placement problems have been long investigated in the optimization field due to numerous applications in location science and classification. Facility location problems are showing their usefulness to communication networks, and more especially from Wireless Mesh Networks (WMNs) field. Recently, such problems are showing their usefulness to communication networks, where facilities could be servers or routers offering connectivity services to clients. In this paper, we deal with the effect of mutation and crossover operators in GA for node placement problem. We evaluate the performance of the proposed system using different selection operators and different distributions of router nodes considering number of covered users parameter. The simulation results show that for Linear and Exponential ranking methods, the system has a good performance for all rates of crossover and mutation.Peer ReviewedPostprint (published version
A Survey on Continuous Time Computations
We provide an overview of theories of continuous time computation. These
theories allow us to understand both the hardness of questions related to
continuous time dynamical systems and the computational power of continuous
time analog models. We survey the existing models, summarizing results, and
point to relevant references in the literature
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