• Conference Object  

      Capacity of gaussian channels with noise uncertainty 

      Denic, S. Z.; Charalambous, Charalambos D.; Djouadi, S. M. (2004)
      In this paper the problem of defining, and computing the capacity of a communication channel when the statistic of an additive noise is not fully known, is addressed. The communication channel is specified as a continuous ...
    • Conference Object  

      Discrete-time risk-sensitive filters with non-Gaussian initial conditions and their ergodic properties 

      Dey, Subhrakanti; Charalambous, Charalambos D. (IEEE, 1999)
      In this paper, we study asymptotic stability properties of risk-sensitive filters with respect to their initial conditions. In particular, we consider a linear time-invariant systems with initial conditions that are not ...
    • Article  

      Experimental determination of the absolute temperature modulation in photothermal microscopy of Y1Ba2Cu3O7 crystals 

      Studenmund, W. R.; Fishman, I. M.; Kino, G. S.; Giapintzakis, John (1997)
      We present a technique to experimentally determine the value of the temperature perturbation ST in photothermal microscopy. Knowledge of δT is necessary for proper analysis of the differential optical reflectivity (∂R/∂T) ...
    • Conference Object  

      First passage risk-sensitive criterion for stochastic evolutions 

      Charalambous, Charalambos D.; Hibey, Joseph L. (1995)
      The purpose of this paper is to investigate in an infinite dimensional space, the first passage problem with a risk-sensitive performance criterion, and to illustrate the asymptotic behavior of the associated value function, ...
    • Conference Object  

      Necessary conditions for partially observed diffusions 

      Charalambous, Charalambos D.; Hibey, Joseph L. (IEEE, 1993)
      We present a new approach to deriving necessary conditions for stochastic partially observed control problems when the control enters the drift coefficient, and correlation between signal and observation noise is allowed. ...
    • Conference Object  

      New finite-dimensional risk-sensitive filters: Small-noise limits 

      Charalambous, Charalambos D.; Dey, Subhrakanti; Elliott, Robert J. (IEEE, 1997)
      This paper is concerned with continuous-time nonlinear risk-sensitive filters. It is shown that for large classes of nonlinearities entering both the dynamics and measurements, these filters are finite-dimensional, ...
    • Conference Object  

      On the role of feedback in the design of perfectly reconstructing equalizers 

      Touri, R.; Voulgaris, P. G.; Hadjicostis, Christoforos N. (2007)
      In this paper we consider the transmission of discrete data via a communication channel that is subject to (additive) noise with a known upper bound on its magnitude but otherwise completely unrestricted behavior. We are ...
    • Conference Object  

      Optimal preprocessing strategies for perfect reconstruction of binary signals under power-constrained transmission 

      Voulgaris, P. G.; Hadjicostis, Christoforos N. (2004)
      In this paper we further explore our deterministic worst-case framework for perfect reconstruction of discrete data transmissions through dispersive communication channels. Specifically, we are concerned with perfect ...
    • Conference Object  

      Robust capacity of white Gaussian noise channels with uncertainty 

      Charalambous, Charalambos D.; Denic, S. Z.; Djouadi, S. M. (2004)
      This paper concerns the problem of defining, and computing the channel capacity of a continuous time additive white Gaussian noise channel when the true frequency response of the channel is not completely known to the ...
    • Article  

      The role of information state and adjoint in relating nonlinear output feedback risk-sensitive control and dynamic games 

      Charalambous, Charalambos D. (1997)
      This paper employs logarithmic transformations to establish relations between continuous-time nonlinear partially observable risk-sensitive control problems and analogous output feedback dynamic games. The first logarithmic ...
    • Conference Object  

      Stochastic models for short-term multipath fading channels: chi-square and Ornstein-Uhlenbeck processes 

      Charalambous, Charalambos D.; Menemenlis, Nickie (IEEE, 1999)
      This paper discusses the use of stochastic differential equations to model signal envelope variations over areas, which are subject to short-term fading effects. The short-term fading effects are modeled using Ornstein-Uhlenbeck ...
    • Conference Object  

      A Systems Approach to Channel Equalization 

      Venkatesh, S.; Voulgaris, P.; Hadjicostis, Christoforos N. (2003)
      In this paper we present a control theoretic frame-work for channel equalization. Channel equalization methods are used to mitigate the effects of inter-symbol interference (ISI). Traditional methods, maximize the signal ...
    • Conference Object  

      Wavelet analysis of motor unit action potentials 

      Pattichis, Constantinos S.; Pattichis, Marios S.; Schizas, Christos N. (IEEE, 1996)
      In this study the usefulness of the wavelet transforms (WT) Daubechies with 4 and 20 coefficients, Chui, and Battle-Lemarie in analyzing MUAPs recorded from normal subjects and subjects suffering with motor neuron disease ...