Browsing Τμήμα Ηλεκτρολόγων Μηχανικών και Μηχανικών Υπολογιστών / Department of Electrical and Computer Engineering by Author "Hadjicostis, Christoforos N."
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Article
55th IEEE Conference on Decision and Control, CDC 2016 [Conference Reports]
Giua, A.; Bullo, F.; Hadjicostis, Christoforos N.; Seatzu, C.; Pasqualetti, F. (2017)
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Article
Algebraic approaches for fault identification in discrete-event systems
Wu, Y.; Hadjicostis, Christoforos N. (2005)In this note, we develop algebraic approaches for fault identification in discrete-event systems that are described by Petri nets. We consider faults in both Petri net transitions and places, and assume that system events ...
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Article
Algorithmic design of perfectly reconstructing equalisers
Touri, R.; Voulgaris, P. G.; Hadjicostis, Christoforos N. (2010)We consider the transmission of a discrete data sequence via a communication channel that is subject to (additive) noise with a known upper bound on its magnitude but otherwise completely unrestricted behaviour. We provide ...
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Article
Aliasing probability calculations for arbitrary compaction under independently selected random test vectors
Hadjicostis, Christoforos N. (2005)This paper discusses a systematic methodology for calculating the exact aliasing probability associated with schemes that use an arbitrary finite-state machine to compact the response of a combinational circuit to a sequence ...
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Conference Object
Aliasing probability calculations in nonlinear compactors
Hadjicostis, Christoforos N. (2003)This paper discusses a systematic methodology for calculating the aliasing probability when an arbitrary finite-state machine is used to compact the response of a combinational circuit to a sequence of randomly generated ...
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Conference Object
Approximating optimal place sensor selection for structural observability in discrete event systems modeled by petri nets
Ru, Y.; Hadjicostis, Christoforos N. (2007)In this paper, we study place sensor selection problems in Discrete Event Systems modeled by Petri nets with outputs (i.e., Petri nets with transition and place sensors). Our goal is to place a minimal number of sensors ...
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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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Article
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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Conference Object
Bound on the probability of HMM misclassification
Keroglou, C.; Hadjicostis, Christoforos N. (2011)In this paper we consider the problem of classifying a sequence of observations among two known hidden Markov models (HMMs). We use a classifier that minimizes the probability of error (i.e., the probability of misclassification), ...
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Article
Bounds on FSM switching activity
Athanasopoulou, E.; Hadjicostis, Christoforos N. (2008)This paper obtains lower and upper bounds for the switching activity on the state lines of a finite state machine (FSM) that is driven by typical input sequences. More specifically, the paper provides bounds on the average ...
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Conference Object
Bounds on max-product algorithms for multiple fault diagnosis in graphs with loops
Le, T.; Hadjicostis, Christoforos N. (Institute of Electrical and Electronics Engineers Inc., 2007)In this paper, we analyze the performance of algorithms that use belief propagation max-product iterations to solve the generalized multiple fault diagnosis (GMFD) problem. The GMFD problem is described by a bipartite ...
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Article
Bounds on the number of markings consistent with label observations in petri nets
Ru, Y.; Hadjicostis, Christoforos N. (2009)In this paper, we consider state estimation in discrete-event systems (DESs) modeled by labeled Petri nets and present upper bounds on the number of system states (or markings) that are consistent with an observed sequence ...
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Conference Object
Bounds on the probability of misclassification among hidden Markov models
Keroglou, C.; Hadjicostis, Christoforos N. (2011)Given a sequence of observations, classification among two known hidden Markov models (HMMs) can be accomplished with a classifier that minimizes the probability of error (i.e., the probability of misclassification) by ...
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Article
Bounds on the size of minimal nonnegative realizations for discrete-time LTI systems
Hadjicostis, Christoforos N. (1999)Nonnegative linear time-invariant (LTI) state-space models are characterized by the property that their state variables and outputs remain nonnegative whenever the initial state and the inputs are nonnegative. Necessary ...
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Conference Object
Capacity of channels with memory and feedback: Encoder properties and dynamic programming
Charalambous, Charalambos D.; Kourtellaris, C. K.; Hadjicostis, Christoforos N. (2010)This paper is concerned with capacity formulae for channels with memory and feedback, properties of the capacity achieving encoder, and dynamic programming for designing optimal encoders. The source is general and the ...