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Search Results: 1 - 10 of 9013 matches for " networks "
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A Comparative Study of Medium Access Control Protocols for Wireless Sensor Networks  [PDF]
Meghan GUNN, Simon G. M. KOO
Int'l J. of Communications, Network and System Sciences (IJCNS) , 2009, DOI: 10.4236/ijcns.2009.28080
Abstract: One of the major constraints in wireless sensor networks (WSNs) is power consumption. In recent years, a lot of efforts have been put into the design of medium access control (MAC) protocols for WSN, in order to reduce energy consumption and enhance the network’s lifetime. In this paper, we surveyed some MAC protocols for WSN and compared their design tradeoffs. The goal is to provide a foundation for future MAC design, and to identify important design issues that allow us to improve the overall performances.
Design of Orthogonal UWB Pulse Waveform for Wireless Multi-Sensor Applications  [PDF]
Hannu Olkkonen, Juuso T. Olkkonen
Wireless Sensor Network (WSN) , 2010, DOI: 10.4236/wsn.2010.211102
Abstract: In this work we propose an orthogonal pulse waveform for wireless ultra wideband (UWB) transmission. The design is based on an ideal low-pass prototype filter having a windowed sinc impulse response. The frequency response of the prototype filter is transferred to the high frequency region using a specific sign modulator. The UWB pulse waveform comprises of the weighted summation of the left singular vectors of the impulse response matrix. The power spectral density of the pulse waveform fulfils the FCC constraint (allowed frequency band 3.1-10.6 GHz) for unlicensed UWB transmission. Applications of the UWB pulse waveform in multi-channel wireless sensor networks are considered.
Experimental Analysis of Voice and Data Transmission Parameters for Mobile Terminals in Cellular Data Networks  [PDF]
Montserrat Jiménez-Licea, Sergio Vidal-Beltrán, José Luis López-Bonilla
Wireless Engineering and Technology (WET) , 2011, DOI: 10.4236/wet.2011.21002
Abstract: This work presents the experimental results related to performance measurements in GSM and GPRS cellular data networks. Two Mobile Terminals were used, in order to take place the scenario. Power Level, Power vs Time, Modula-tion Analysis, Modulation Spectrum, (BER) Bit Error Rate and Throughput were considered in this analysis.
An Intelligent Data Filtering Scheme for Real Time Monitoring of Physiological Traits  [PDF]
Israfil Biswas, Brendan Walker
Int'l J. of Communications, Network and System Sciences (IJCNS) , 2011, DOI: 10.4236/ijcns.2011.42013
Abstract: This paper illustrates a real time monitoring system to examine psychological behaviors over wireless networks and recommends a generic filter library for the system. Our goal is to develop “PsychoFIZZ”—a Python source project that communicates with multiple Digital Sample Units (DSUs) by filtering raw data and interpreting the data. The new filtering scheme should be able to work in coordination with the current monitoring system and our experiment results show that the library enhances the performance of the monitoring system.
Social Balance in the Triangle-Growing Networks  [PDF]
Wei Liu, Qing-Kuan Meng
Social Networking (SN) , 2013, DOI: 10.4236/sn.2013.23014
Abstract: In this article, we construct a triangle-growing network with tunable clusters and study the social balance dynamics in this network. The built network, which could reflect more features of real communities, has more triangle relations than the ordinary random-growing network. Then we apply the local triad social dynamics to the built network. The effects of the different cluster coefficients and the initial states to the final stationary states are discussed. Some new features of the sparse networks are found as well.
Follow the Multitude—A Thermodynamic Approach  [PDF]
Oded Kafri
Natural Science (NS) , 2014, DOI: 10.4236/ns.2014.67051

When a bit is added to a file, its entropy increases by one nat regardless of the length of the file or the value of the bit. However, when a node is added to a network, the entropy increase is a function of the ratio between the links and the nodes in the network. Therefore, the thermodynamic incentive for a node to join a highly linked network is higher than to join a poorly linked network.

A Combination Approach to Community Detection in Social Networks by Utilizing Structural and Attribute Data  [PDF]
Nasif Muslim
Social Networking (SN) , 2016, DOI: 10.4236/sn.2016.51002
Abstract: Community detection is one of the important tasks of social network analysis. It has significant practical importance for achieving cost-effective solutions for problems in the area of search engine optimization, spam detection, viral marketing, counter-terrorism, epidemic modeling, etc. In recent years, there has been an exponential growth of online social platforms such as Twitter, Facebook, Google+, Pinterest and Tumblr, as people can easily connect to each other in the Internet era overcoming geographical barriers. This has brought about new forms of social interaction, dialogue, exchange and collaboration across diverse social networks of unprecedented scales. At the same time, it presents new challenges and demands more effective, as well as scalable, graphmining techniques because the extraction of novel and useful knowledge from massive amount of graph data holds the key to the analysis of social networks in a much larger scale. In this research paper, the problem to find communities within social networks is considered. Existing community detection techniques utilize the topological structure of the social network, but a proper combination of the available attribute data, which represents the properties of the participants or actors, and the structure data of the social network graph is promising for the detection of more accurate and meaningful communities.
Living Dead Networks
Eugene Thacker
Fibreculture Journal , 2005,
Abstract: This essay explores, through a series of condensed modules, the ways in which contagion operates in both biological and informational networks.Through an examination of the fields of information security and medical surveillance, computer viruses and mathematical epidemiology, and pathogenic information and informed pathogens, this essay asks how the political relation between 'control' and 'emergence' is formed in networks in which the distinction between information and biology breaks down.
Modelling and Analysis of TCP Performance in Wireless Multihop Networks  [PDF]
Hannan Xiao, Ying Zhang, James Malcolm, Bruce Christianson, Kee Chaing Chua
Wireless Sensor Network (WSN) , 2010, DOI: 10.4236/wsn.201027061
Abstract: Researchers have used extensive simulation and experimental studies to understand TCP performance in wireless multihop networks. In contrast, the objective of this paper is to theoretically analyze TCP performance in this environment. By examining the case of running one TCP session over a string topology, a system model for analyzing TCP performance in multihop wireless networks is proposed, which considers packet buffering, contention of nodes for access to the wireless channel, and spatial reuse of the wireless channel. Markov chain modelling is applied to analyze this system model. Analytical results show that when the number of hops that the TCP session crosses is ?xed, the TCP throughput is independent of the TCP congestion window size. When the number of hops increases from one, the TCP throughput decreases ?rst, and then stabilizes when the number of hops becomes large. The analysis is validated by comparing the numerical and simulation results.
A Proposal of Sensor Data Collection System Using Mobile Relay Nodes  [PDF]
Ryota Ayaki, Hideki Shimada, Kenya Sato
Wireless Sensor Network (WSN) , 2012, DOI: 10.4236/wsn.2012.41001
Abstract: In recent years, as embedded devices become smaller, cheaper and more diverse, the demand for urban sensing systems that present valuable information to users is increasing. However, in achieving urban sensing systems, the communication channel from the sensors to the data centers pose a problem, especially in respect to the cost of furnishing IP/mobile networks for each and every one of the sensor nodes. Many existing researches attempt to tackle this problem, but they generally limit either the types of sensors used or the distances among the sensors. In this paper, we propose a new sensor data collection system model in which mobile relay nodes transport the sensor data to the data center. We ran simulations under conditions imitating the real world to verify the practicality of the proposed system. This simulation uses data accumulated from traffic surveys to closely imitate pedestrians in the real world. We evaluated that the proposed system has sufficient ability to use in urban sensing systems that are not under the real-time constraint.
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