383 research outputs found
A Game-Theoretic Approach to Energy Trading in the Smart Grid
Electric storage units constitute a key element in the emerging smart grid
system. In this paper, the interactions and energy trading decisions of a
number of geographically distributed storage units are studied using a novel
framework based on game theory. In particular, a noncooperative game is
formulated between storage units, such as PHEVs, or an array of batteries that
are trading their stored energy. Here, each storage unit's owner can decide on
the maximum amount of energy to sell in a local market so as to maximize a
utility that reflects the tradeoff between the revenues from energy trading and
the accompanying costs. Then in this energy exchange market between the storage
units and the smart grid elements, the price at which energy is traded is
determined via an auction mechanism. The game is shown to admit at least one
Nash equilibrium and a novel proposed algorithm that is guaranteed to reach
such an equilibrium point is proposed. Simulation results show that the
proposed approach yields significant performance improvements, in terms of the
average utility per storage unit, reaching up to 130.2% compared to a
conventional greedy approach.Comment: 11 pages, 11 figures, journa
INVESTIGATION ON THE EFFECT OF SPORT AND ART EDUCATION ON BODY IMAGE
The purpose of this study is determining body image in individuals with sports and fine arts education. 137 male and 120 female, total of 257, sports and fine arts students were participated in the study. Body-Cathexis Scale (BCS) were used. Independent Samples t- test was used for statically processing. Body Image score according to gender found at male 77.96 and female 80.12. Body Image score found at sports students 74.05 and fine arts students 84.03. There was a significant no difference in between sports students and fine arts students in Body Image Score (p>0.05) in gender. There was a significant difference in between sports faculty and fine arts faculty according male and female students in Body Image Score at p<0.001 level. Female students are according male students under greater risk regarding the body image. Body image points were more positively at student of sports than student of fine art. It is thought that sport education affects body image more positively than fine arts education. Getting with sports education could contribute to a positive body image levels
Opinion Dynamics in Social Networks through Mean-Field Games
Emulation, mimicry, and herding behaviors are phenomena that are observed when multiple social groups interact. To study such phenomena, we consider in this paper a large population of homogeneous social networks. Each such network is characterized by a vector state, a vector-valued controlled input and a vector-valued exogenous disturbance. The controlled input of each network is to align its state to the mean distribution of other networks’ states in spite of the actions of the disturbance. One of the contributions of this paper is a detailed analysis of the resulting mean field game for the cases of both polytopic and L2 bounds on controls and disturbances. A second contribution is the establishment of a robust mean-field equilibrium, that is, a solution including the worst-case value function, the state feedback best-responses for the controlled inputs and worst-case disturbances, and a density evolution. This solution is characterized by the property that no player can benefit from a unilateral deviation even in the presence of the disturbance. As a third contribution, microscopic and macroscopic analyses are carried out to show convergence properties of the population distribution using stochastic stability theory
A Cooperative Bayesian Nonparametric Framework for Primary User Activity Monitoring in Cognitive Radio Network
This paper introduces a novel approach that enables a number of cognitive
radio devices that are observing the availability pattern of a number of
primary users(PUs), to cooperate and use \emph{Bayesian nonparametric}
techniques to estimate the distributions of the PUs' activity pattern, assumed
to be completely unknown. In the proposed model, each cognitive node may have
its own individual view on each PU's distribution, and, hence, seeks to find
partners having a correlated perception. To address this problem, a coalitional
game is formulated between the cognitive devices and an algorithm for
cooperative coalition formation is proposed. It is shown that the proposed
coalition formation algorithm allows the cognitive nodes that are experiencing
a similar behavior from some PUs to self-organize into disjoint, independent
coalitions. Inside each coalition, the cooperative cognitive nodes use a
combination of Bayesian nonparametric models such as the Dirichlet process and
statistical goodness of fit techniques in order to improve the accuracy of the
estimated PUs' activity distributions. Simulation results show that the
proposed algorithm significantly improves the estimates of the PUs'
distributions and yields a performance advantage, in terms of reduction of the
average achieved Kullback-Leibler distance between the real and the estimated
distributions, reaching up to 36.5% relative the non-cooperative estimates. The
results also show that the proposed algorithm enables the cognitive nodes to
adapt their cooperative decisions when the actual PUs' distributions change due
to, for example, PU mobility.Comment: IEEE Journal on Selected Areas in Communications (JSAC), to appear,
201
Detecting event-related recurrences by symbolic analysis: Applications to human language processing
Quasistationarity is ubiquitous in complex dynamical systems. In brain
dynamics there is ample evidence that event-related potentials reflect such
quasistationary states. In order to detect them from time series, several
segmentation techniques have been proposed. In this study we elaborate a recent
approach for detecting quasistationary states as recurrence domains by means of
recurrence analysis and subsequent symbolisation methods. As a result,
recurrence domains are obtained as partition cells that can be further aligned
and unified for different realisations. We address two pertinent problems of
contemporary recurrence analysis and present possible solutions for them.Comment: 24 pages, 6 figures. Draft version to appear in Proc Royal Soc
Coalitional Games in Partition Form for Joint Spectrum Sensing and Access in Cognitive Radio Networks
Unlicensed secondary users (SUs) in cognitive radio networks are subject to
an inherent tradeoff between spectrum sensing and spectrum access. Although
each SU has an incentive to sense the primary user (PU) channels for locating
spectrum holes, this exploration of the spectrum can come at the expense of a
shorter transmission time, and, hence, a possibly smaller capacity for data
transmission. This paper investigates the impact of this tradeoff on the
cooperative strategies of a network of SUs that seek to cooperate in order to
improve their view of the spectrum (sensing), reduce the possibility of
interference among each other, and improve their transmission capacity
(access). The problem is modeled as a coalitional game in partition form and an
algorithm for coalition formation is proposed. Using the proposed algorithm,
the SUs can make individual distributed decisions to join or leave a coalition
while maximizing their utilities which capture the average time spent for
sensing as well as the capacity achieved while accessing the spectrum. It is
shown that, by using the proposed algorithm, the SUs can self-organize into a
network partition composed of disjoint coalitions, with the members of each
coalition cooperating to jointly optimize their sensing and access performance.
Simulation results show the performance improvement that the proposed algorithm
yields with respect to the non-cooperative case. The results also show how the
algorithm allows the SUs to self-adapt to changes in the environment such as
the change in the traffic of the PUs, or slow mobility.Comment: IEEE Journal on Selected Topics in Signal Processing (JSTSP), Special
Issue on Game Theory, to appear, 201
Effective action for Einstein-Maxwell theory at order RF**4
We use a recently derived integral representation of the one-loop effective
action in Einstein-Maxwell theory for an explicit calculation of the part of
the effective action containing the information on the low energy limit of the
five-point amplitudes involving one graviton, four photons and either a scalar
or spinor loop. All available identities are used to get the result into a
relatively compact form.Comment: 13 pages, no figure
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