Search results for "LESS"
showing 10 items of 2452 documents
Video Streaming Distribution in VANETs
2011
Streaming applications will rapidly develop and contribute a significant amount of traffic in the near future. A problem, scarcely addressed so far, is how to distribute video streaming traffic from one source to all nodes in an urban vehicular network. This problem significantly differs from previous work on broadcast and multicast in ad hoc networks because of the highly dynamic topology of vehicular networks and the strict delay requirements of streaming applications. We present a solution for intervehicular communications, called Streaming Urban Video (SUV), that 1) is fully distributed and dynamically adapts to topology changes, and 2) leverages the characteristics of streaming applica…
Castadiva: A Test-Bed Architecture for Mobile AD HOC Networks
2007
Evaluating and deploying all sorts of protocols and applications designed for wireless ad hoc networks in a real environment is an important and urgent task. Traditionally, all the proposals made rely solely on simulator results. However, as different research groups develop different solutions to solve problems related to these new networks, it becomes more and more important to migrate the proposed solutions to a real environment. In this work we present Castadiva, a test-bed architecture that allows validating software solutions for ad hoc networks using low-cost, of the-shelf devices and open source software. Through a friendly user interface, Castadiva offers the possibility to define …
MP2P Network in Collecting Data from Sensor Networks
2006
Wireless sensor networks provide numerous applications today. At the same time modern wireless short-range communication technologies combined with mobile users create environments for mobile peerto- peer networks. This paper discusses a concept of an application in which an MP2P network is used for collecting sensor network data. This model requires certain places with a high mobile user density in order to function. Simulation results indicate that the model can be used in environments where these requirements are met.
An accurate and efficient collaborative intrusion detection framework to secure vehicular networks
2015
Display Omitted We design and implement an accurate and lightweight intrusion detection framework, called AECFV.AECFV aims to protect the vehicular ad hoc networks (VANETs) against the most dangerous attacks that could occurred on this network.AECFV take into account the VANET's characteristics such as high node's mobility and rapid topology change.AECFV exhibits a high detection rate, low false positive rate, faster attack detection, and lower communication overhead. The advancement of wireless communication leads researchers to develop and conceive the idea of vehicular networks, also known as vehicular ad hoc networks (VANETs). Security in such network is mandatory due to a vital informa…
A MODEL FOR VESTIBULAR FUNCTION IN ALTERED GRAVITATIONAL STATES
1979
ABSTRACT During evolution, the vestibular organ was made to serve mainly two purposes: 1) to guide eye movements during sharp turns, so that the point of fixation in the visual field can be kept steady, a function accomplished by the semicircular canal system and 2) to indicate the terrestrial vertical, so that upright posture and gait can be maintained even in the dark. The otolith system serves the latter purpose. Since the function of the semicircular canal system does not depend on gravity, it is not grossly disturbed by gravitational levels different from 1 g . The proper function of the otolith system depends entirely on the presence of a gravitational force vector of 9.8/m/sec2 direc…
General remarks on the role of the vestibular system in weightlessness
1987
Different methods are described to experimentally achieve weightlessness. Since the function of the otolith system depends on the presence of contact forces opposing gravity, it is disabled in weightlessness and may send misleading positional information to the brain. Without the contributions of the otolith system it is difficult in space to distinguish self-motion from object motion. Furthermore, the disintegration of information from the neck position receptors from those of the otolith system can lead to additional illusory positional sensations. Since the function of the semicircular canal system in previous space flights was found to be essentially undisturbed, the vestibular experime…
Responses to eccentric rotation in two space-bound subjects
1993
Two subjects were rotated eccentrically in the manner described previously. In contrast to a normal control group, settings of a luminous line to the subjective vertical were almost unrelated to the gravitoinertial vector before, and totally so shortly after, space flight. Only 3 days postflight did a clear relation to the gravitoinertial vector re-establish itself in the one subject who actually flew. The correspondence became normal 5 days after the flight. Since there were no clinical abnormalities evident in the subjects, it is suggested that both subjects suppressed their vestibular information, presumably as an effect of vestibular deconditioning training before the flight. In additio…
Comparison of a Manual and an Automated Method to Estimate the Number of Uterine Eggs in Anisakid Nematodes: To Coulter or Not to Coulter. Is That th…
2007
Studies reporting numbers of eggs in vagina and utero in nematodes often give little information of the technique used for the estimations. This situation hampers comparison among studies, because, so far, differences in estimations provided by different techniques have not been assessed. This note examines whether a manual method based on visual counts in aliquots and an automated method using a Coulter counter yield equivalent estimations of egg numbers in vagina and utero of 3 anisakid nematode species (Anisakis simplex, Pseudoterranova decipiens, and Contracaecum osculatum). The number of eggs from 50 females per nematode species was estimated using both techniques. The automated and ma…
A convex optimization approach for vibration control of base isolated structures with limited wireless communication capacity
2010
The problem of H ∞ control design for vibration reduction of a base isolated structure with limited wireless communication capacity is studied in this paper. The network under consideration is subjected to measurement quantization, signal transmission delay, and data packet dropout, which appear typically in a network environment. Based on Lyapunov-Krasovskii functional (LKF) theory, some delay-range-dependent conditions are established for the existence of desired controllers such that the resulting closed-loop system is asymptotically stable and its performance is kept within a prescribed level. Finally, some simulation results are given to illustrate the effectiveness of our method.
A User-Balanced System for IP Telephony in WLANs
2008
Wireless IP telephony is becoming very popular between the users of large wireless local area networks (WLANs). This increment has been mainly caused because it allows cost savings. Although, large WLANs use to provide high availability and redundancy, WLANs lack on the available throughput when there are many IP telephony users. In this paper we present a system that reallocates IP telephony devices when the system detects that an AP is overloaded. The algorithm and the frames used for our proposal are described. Measurements taken show how the bandwidth consumed is transferred from an access point to another when our proposal is running. Finally, we show the time needed to re-associate re…