12,014 research outputs found
Trigger strategies for SUSY searches at the LHC
Supersymmetry will be searched for in a variety of final states at the LHC.
It is crucial that a robust, efficient and unbiased trigger selection for SUSY
is implemented from the very early days of data taking. After a brief
description of the ATLAS and the CMS trigger systems, and a more in-depth
discussion of the ATLAS High-Level Trigger, a triggering strategy is outlined
for early SUSY searches at the LHC.Comment: Submitted for the SUSY07 Proceedings, 4 pages, 3 eps figures, LaTe
Synchronization between variable time delayed systems and cryptography
In this letter we consider a prototype model which is described as an
autonomous continuous time delayed differential equation with just one
variable. The chaos has been investigated with variable delay time and the
synchronization phenomenon is examined both numerically and analytically using
the Krasovskii-Lyapunov functions. We have applied adaptive coupling law for
synchronization,where the coupling equation also contains delay with modulated
time. We also studied the effect of cryptography for this coupled system and
the message extraction procedure is illustrated with the help of simulated
results.Comment: 9 pages,3 figures. Submitted to EP
On the Consensus Threshold for the Opinion Dynamics of Krause-Hegselmann
In the consensus model of Krause-Hegselmann, opinions are real numbers
between 0 and 1 and two agents are compatible if the difference of their
opinions is smaller than the confidence bound parameter \epsilon. A randomly
chosen agent takes the average of the opinions of all neighbouring agents which
are compatible with it. We propose a conjecture, based on numerical evidence,
on the value of the consensus threshold \epsilon_c of this model. We claim that
\epsilon_c can take only two possible values, depending on the behaviour of the
average degree d of the graph representing the social relationships, when the
population N goes to infinity: if d diverges when N goes to infinity,
\epsilon_c equals the consensus threshold \epsilon_i ~ 0.2 on the complete
graph; if instead d stays finite when N goes to infinity, \epsilon_c=1/2 as for
the model of Deffuant et al.Comment: 15 pages, 7 figures, to appear in International Journal of Modern
Physics C 16, issue 2 (2005
The Sznajd Consensus Model with Continuous Opinions
In the consensus model of Sznajd, opinions are integers and a randomly chosen
pair of neighbouring agents with the same opinion forces all their neighbours
to share that opinion. We propose a simple extension of the model to continuous
opinions, based on the criterion of bounded confidence which is at the basis of
other popular consensus models. Here the opinion s is a real number between 0
and 1, and a parameter \epsilon is introduced such that two agents are
compatible if their opinions differ from each other by less than \epsilon. If
two neighbouring agents are compatible, they take the mean s_m of their
opinions and try to impose this value to their neighbours. We find that if all
neighbours take the average opinion s_m the system reaches complete consensus
for any value of the confidence bound \epsilon. We propose as well a weaker
prescription for the dynamics and discuss the corresponding results.Comment: 11 pages, 4 figures. To appear in International Journal of Modern
Physics
Do extremists impose the structure of social networks?
The structure and the properties of complex networks essentially depend on
the way how nodes get connected to each other. We assume here that each node
has a feature which attracts the others. We model the situation by assigning
two numbers to each node, \omega and \alpha, where \omega indicates some
property of the node and \alpha the affinity towards that property. A node A is
more likely to establish a connection with a node B if B has a high value of
\omega and A has a high value of \alpha. Simple computer simulations show that
networks built according to this principle have a degree distribution with a
power law tail, whose exponent is determined only by the nodes with the largest
value of the affinity \alpha (the "extremists"). This means that the extremists
lead the formation process of the network and manage to shape the final
topology of the system. The latter phenomenon may have implications in the
study of social networks and in epidemiology.Comment: 4 pages, 3 figure
The Krause-Hegselmann Consensus Model with Discrete Opinions
The consensus model of Krause and Hegselmann can be naturally extended to the
case in which opinions are integer instead of real numbers. Our algorithm is
much faster than the original version and thus more suitable for applications.
For the case of a society in which everybody can talk to everybody else, we
find that the chance to reach consensus is much higher as compared to other
models; if the number of possible opinions Q<=7, in fact, consensus is always
reached, which might explain the stability of political coalitions with more
than three or four parties. For Q>7 the number S of surviving opinions is
approximately the same independently of the size N of the population, as long
as Q<N. We considered as well the more realistic case of a society structured
like a Barabasi-Albert network; here the consensus threshold depends on the
outdegree of the nodes and we find a simple scaling law for S, as observed for
the discretized Deffuant model.Comment: 12 pages, 6 figure
Transformation of Rural Teachers Earning Graduate Degrees
This study tells the stories of four successful graduate students within a cohort of learners who were earning graduate degrees in technology for education and training by distance. The students were practicing teachers in the Dakota Interactive Academic Link (DIAL) consortium. Courses were offered by the University of South Dakota, using videoconferencing through the statewide Digital Distance Network (DDN) and WebCT asynchronous discussions. Mezirows 1991 theory of transformative learning suggests that adult learners may experience a transformational experience. Results showed that the four study participants experienced major changes in their way of thinking about learning and themselves. Conducting longitudinal studies in which adults are interviewed throughout their graduate school experience is recommended
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