11 research outputs found
Equality of averaged and quenched large deviations for random walks in random environments in dimensions four and higher
We consider large deviations for nearest-neighbor random walk in a uniformly
elliptic i.i.d. environment. It is easy to see that the quenched and the
averaged rate functions are not identically equal. When the dimension is at
least four and Sznitman's transience condition (T) is satisfied, we prove that
these rate functions are finite and equal on a closed set whose interior
contains every nonzero velocity at which the rate functions vanish.Comment: 17 pages. Minor revision. In particular, note the change in the title
of the paper. To appear in Probability Theory and Related Fields
Stretched Polymers in Random Environment
We survey recent results and open questions on the ballistic phase of
stretched polymers in both annealed and quenched random environments.Comment: Dedicated to Erwin Bolthausen on the occasion of his 65th birthda
Lyapunov exponents of Green's functions for random potentials tending to zero
We consider quenched and annealed Lyapunov exponents for the Green's function
of , where the potentials , are i.i.d.
nonnegative random variables and is a scalar. We present a
probabilistic proof that both Lyapunov exponents scale like as
tends to 0. Here the constant is the same for the quenched as for
the annealed exponent and is computed explicitly. This improves results
obtained previously by Wei-Min Wang. We also consider other ways to send the
potential to zero than multiplying it by a small number.Comment: 16 pages, 3 figures. 1 figure added, very minor corrections. To
appear in Probability Theory and Related Fields. The final publication is
available at http://www.springerlink.com, see
http://www.springerlink.com/content/p0873kv68315847x/?p=4106c52fc57743eba322052bb931e8ac&pi=21
The continuum disordered pinning model
10.1007/s00440-014-0606-4Probability Theory and Related Fields1644349717-5
Dynamic load balancing techniques for distributed complex event processing systems
Applying real-time, cost-effective Complex Event processing (CEP) in the cloud has been an important goal in recent years. Distributed Stream Processing Systems (DSPS) have been widely adopted by major computing companies such as Facebook and Twitter for performing scalable event processing in streaming data. However, dynamically balancing the load of the DSPS’ components can be particularly challenging due to the high volume of data, the components’ state management needs, and the low latency processing requirements. Systems should be able to cope with these challenges and adapt to dynamic and unpredictable load changes in real-time. Our approach makes the following contributions: (i) we formulate the load balancing problem in distributed CEP systems as an instance of the job-shop scheduling problem, and (ii) we present a novel framework that dynamically balances the load of CEP engines in real-time and adapts to sudden changes in the volume of streaming data by exploiting two balancing policies. Our detailed experimental evaluation using data from the Twitter social network indicates the benefits of our approach in the system’s throughput. © IFIP International Federation for Information Processing 2016
Intelligent Urban data monitoring for smart cities
Urban data management is already an essential element of modern cities. The authorities can build on the variety of automatically generated information and develop intelligent services that improve citizens daily life, save environmental resources or aid in coping with emergencies. From a data mining perspective, urban data introduce a lot of challenges. Data volume, velocity and veracity are some obvious obstacles. However, there are even more issues of equal importance like data quality, resilience, privacy and security. In this paper we describe the development of a set of techniques and frameworks that aim at effective and efficient urban data management in real settings. To do this, we collaborated with the city of Dublin and worked on real problems and data. Our solutions were integrated in a system that was evaluated and is currently utilized by the city. © Springer International Publishing AG 2016
INSIGHT: Dynamic traffic management using heterogeneous urban data
In this demo we present INSIGHT, a system that provides traffic event detection in Dublin by exploiting Big Data and Crowdsourcing techniques. Our system is able to process and analyze input from multiple heterogeneous urban data sources
INSIGHT: Dynamic traffic management using heterogeneous urban data
In this demo we present INSIGHT, a system that provides traffic event detection in Dublin by exploiting Big Data and Crowdsourcing techniques. Our system is able to process and analyze input from multiple heterogeneous urban data sources. © Springer International Publishing AG 2016