Browsing by Author "Charalambous, T."
Now showing items 1-20 of 43
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Conference Object
Approximation of Markov processes by lower dimensional processes
Tzortzis, I.; Charalambous, C. D.; Charalambous, T.; Hadjicostis, Christoforos N.; Johansson, M. (Institute of Electrical and Electronics Engineers Inc., 2014)In this paper, we investigate the problem of aggregating a given finite-state Markov process by another process with fewer states. The aggregation utilizes total variation distance as a measure of discriminating the Markov ...
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Conference Object
Approximation of Markov processes by lower dimensional processes
Tzortzis, I.; Charalambous, Charalambos D.; Charalambous, T.; Hadjicostis, Christoforos N.; Johansson, M. (Institute of Electrical and Electronics Engineers Inc., 2014)In this paper, we investigate the problem of aggregating a given finite-state Markov process by another process with fewer states. The aggregation utilizes total variation distance as a measure of discriminating the Markov ...
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Article
Approximation of Markov Processes by Lower Dimensional Processes via Total Variation Metrics
Tzortzis, I.; Charalambous, Charalambos D.; Charalambous, T.; Hadjicostis, Christoforos N.; Johansson, M. (2017)The aim of this paper is to approximate a Finite-State Markov (FSM) process by another process defined on a lower dimensional state space, called the approximating process, with respect to a total variation distance fidelity ...
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Article
Approximation of Markov Processes by Lower Dimensional Processes via Total Variation Metrics
Tzortzis, I.; Charalambous, C. D.; Charalambous, T.; Hadjicostis, Christoforos N.; Johansson, M. (2017)The aim of this paper is to approximate a Finite-State Markov (FSM) process by another process defined on a lower dimensional state space, called the approximating process, with respect to a total variation distance fidelity ...
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Conference Object
Asynchronous coordination of distributed energy resources for the provisioning of ancillary services
Hadjicostis, Christoforos N.; Charalambous, T. (2011)This paper analyzes the stability of asynchronous coordination protocols and studies their application to energy resource provisioning of ancillary services in power grids. First, we consider and analyze a protocol that ...
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Average consensus in the presence of delays in directed graph topologies
Hadjicostis, Christoforos N.; Charalambous, T. (2014)Classical distributed algorithms for asymptotic average consensus typically assume timely and reliable exchange of information between neighboring components of a given multi-component system. These assumptions are not ...
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Conference Object
Average consensus in the presence of dynamically changing directed topologies and time delays
Charalambous, T.; Hadjicostis, Christoforos N. (Institute of Electrical and Electronics Engineers Inc., 2014)We have recently proposed a robustified ratio consensus algorithm which achieves asymptotic convergence to the global average in a distributed fashion in static strongly connected digraphs, despite the possible presence ...
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Buffer-aided relay selection for cooperative diversity systems without delay constraints
Krikidis, Ioannis A.; Charalambous, T.; Thompson, J. S. (2012)
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A buffer-aided successive opportunistic relay selection scheme with power adaptation and inter-relay interference cancellation for cooperative diversity systems
Nomikos, N.; Charalambous, T.; Krikidis, Ioannis A.; Skoutas, D. N.; Vouyioukas, D.; Johansson, M. (2015)
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Conference Object
Buffer-aided successive opportunistic relaying with inter-relay interference cancellation
Nomikos, N.; Charalambous, T.; Krikidis, Ioannis A.; Skoutas, D. N.; Vouyioukas, D.; Johansson, M. (2013)
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Conference Object
Capacity improvement through buffer-aided successive opportunistic relaying
Nomikos, N.; Vouyioukas, D.; Charalambous, T.; Krikidis, Ioannis A.; Skoutas, D. N.; Johansson, M. (2013)
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Conference Object
Decentralised minimum-time average consensus in digraphs
Charalambous, T.; Yuan, Y.; Yang, T.; Pan, W.; Hadjicostis, Christoforos N.; Johansson, M. (Institute of Electrical and Electronics Engineers Inc., 2013)Distributed algorithms for average consensus in directed graphs are typically asymptotic in the literature. In this work, we propose a protocol to distributively reach average consensus in a finite number of steps on ...
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Conference Object
Delay-and diversity-Aware buffer-Aided relay selection policies in cooperative networks
Poulimeneas, D.; Charalambous, T.; Nomikos, N.; Krikidis, Ioannis A.; Vouyioukas, D.; Johansson, M. (2016)
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Conference Object
A delay-aware hybrid relay selection policy
Poulimeneas, D.; Charalambous, T.; Nomikos, N.; Krikidis, Ioannis A.; Vouyioukas, D.; Johansson, M. (2016)
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Distributed Finite-Time Average Consensus in Digraphs in the Presence of Time Delays
Charalambous, T.; Yuan, Y.; Yang, T.; Pan, W.; Hadjicostis, Christoforos N.; Johansson, M. (2015)Most algorithms for distributed averaging only guarantee asymptotic convergence. This paper introduces a distributed protocol that allows nodes to find the exact average of the initial values in a finite and minimum number ...
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Distributed Finite-Time Computation of Digraph Parameters: Left-Eigenvector, Out-Degree and Spectrum
Charalambous, T.; Rabbat, M. G.; Johansson, M.; Hadjicostis, Christoforos N. (2016)Many of the algorithms that have been proposed in the field of distributed computation rely on assumptions that require nodes to be aware of some global parameters. In this paper, we propose algorithms to compute some ...
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Conference Object
Distributed formation of balanced and bistochastic weighted digraphs in multi-agent systems
Charalambous, T.; Hadjicostis, Christoforos N. (2013)We propose two distributed algorithms, one for solving the weight-balance problem and another for solving the bistochastic matrix formation problem, in a distributed system whose components (nodes) can exchange information ...
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Conference Object
Distributed minimum-time weight balancing over digraphs
Charalambous, T.; Hadjicostis, Christoforos N.; Johansson, M. (IEEE Computer Society, 2014)We address the weight-balancing problem for a distributed system whose components (nodes) can exchange information via interconnection links (edges) that form an arbitrary, possibly directed, communication topology (digraph). ...
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Conference Object
Distributed network size estimation and average degree estimation and control in networks isomorphic to directed graphs
Shames, I.; Charalambous, T.; Hadjicostis, Christoforos N.; Johansson, M. (2012)Many properties of interest in graph structures are based on the nodes' average degree (i.e., the average number of edges incident to/from each node). In this work, we present asynchronous distributed algorithms, based on ...
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Article
Distributed weight balancing over digraphs
Rikos, A. I.; Charalambous, T.; Hadjicostis, Christoforos N. (2014)A weighted digraph is balanced if, for each node, the sum of the weights of the edges outgoing from that node is equal to the sum of the weights of the edges incoming to that node. Weight-balanced digraphs play a key role ...