• Conference Object  

      How fast are the two-dimensional gaussian waves? 

      Baxevani, Anastassia; Podgórski, K.; Rychlik, I. (2002)
      For a stationary two-dimensional random field evolving in time, we derive the intensity distributions of appropriately defined velocities of crossing contours. The results are based on a generalization of the Rice formula. ...
    • Article  

      The impact of randomization in smoothing networks 

      Mavronicolas, Marios; Sauerwald, T. (2010)
      We revisit randomized smoothing networks (Herlihy and Tirthapura in J Parallel Distrib Comput 66(5):626-632, 2006), which are made up of balancers and wires. We assume that balancers are oriented independently and uniformly ...
    • Conference Object  

      Improved performance bounds on max-product algorithms for multiple fault diagnosis in graphs with loops 

      Le, T.; Hadjicostis, Christoforos N. (2008)
      In this paper, we analyze the performance of belief propagation max-product algorithms when used to solve the multiple fault diagnosis (MFD) problem. The MFD problem is described by a bipartite diagnosis graph (BDG) which ...
    • Conference Object  

      IPMicra: An IP-address based location aware distributed web crawler 

      Papapetrou, Odysseas; Samaras, George S. (2004)
      Distributed crawling is able to overcome Important limitations of the traditional single-sourced web crawling systems. However, the optimal benefit of distributed crawling is usually limited to the sites hosting the crawlers, ...
    • Article  

      Minimax games for stochastic systems subject to relative entropy uncertainty: Applications to SDEs on Hilbert spaces 

      Ahmed, N. U.; Charalambous, Charalambos D. (2007)
      In this paper, we consider minimax games for stochastic uncertain systems with the pay-off being a nonlinear functional of the uncertain measure where the uncertainty is measured in terms of relative entropy between the ...
    • Conference Object  

      Modelling of the high firing variability of real cortical neurons with the temporal noisy-leaky integrator neuron model 

      Christodoulou, Chris C.; Clarkson, Trevor G.; Bugmann, Guido; Taylor, John G. (IEEE, 1994)
      Using the Temporal Noisy-Leaky Integrator (TNLI) neuron model with reset, we observed that high firing variability can be achieved for certain input parameter values which results from the temporal summation of noise in ...
    • 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  

      Nonlinear estimation for a class of systems 

      Charalambous, Charalambos D.; Socratous, Y. (2006)
      This paper considers nonlinear estimation problems for a class of models, and employs relative entropy to describe the uncertainty classes. Two problems are formulated and their solutions are sought. 1) When the transition ...
    • Article  

      Nonlinear estimation for a class of systems 

      Socratous, Y.; Rezaei, F.; Charalambous, Charalambos D. (2009)
      This paper considers nonlinear estimation problems for classes of models, and employs relative entropy to describe the uncertainty classes. Two optimization problems are formulated on general Banach spaces, and their ...
    • Article  

      Nonparametric Maximum Entropy 

      Politis, Dimitris Nicolas (1993)
      The standard maximum entropy method of Burg and the resulting autoregressive model has been widely applied for spectrum estimation and prediction. A generalization of the maximum entropy formalism in a nonparametric setting ...
    • Conference Object  

      Note on the distribution of extreme wave crests 

      Baxevani, Anastassia; Hagberg, O.; Rychlik, I. (2005)
      The sea elevation at a fixed point is modelled by means of a second order model, which is a smooth algebraic function of a vector valued Gaussian process. Asymptotic methods, presented first in [1], are used to estimate ...
    • Conference Object  

      On the channel capacity of wireless fading channels 

      Charalambous, Charalambos D.; Denic, S. (2002)
      The objectives of this paper are twofold. First, to point out the significance of certain results on stochastic processes in computing the channel capacity for flat fading wireless channels. Second, to design an optimal ...
    • 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 ...
    • Article  

      Partially observable nonlinear risk-sensitive control problems: Dynamic programming and verification theorems 

      Charalambous, Charalambos D. (1997)
      In this paper, we consider continuous-time partially observable optimal control problems with exponential-of-integral cost criteria. We derive a rigorous verification theorem when the state and control enter nonlinear in ...
    • Article  

      Performance analysis for a changepoint problem 

      Hibey, J. L.; Charalambous, Charalambos D. (1999)
      Nonlinear stochastic differential equations are used to model a version of the changepoint problem. State estimates of the minimum mean-square-error-type are used in likelihood-ratio tests to detect the time of change. ...
    • Article  

      Poisson approximation for a sum of dependent indicators: An alternative approach 

      Papadatos, Nickos; Papathanasiou, Vassilis (2002)
      The random variables X1, X2,...,Xn are said to be totally negatively dependent (TND) if and only if the random variables Xi and Σj≠i Xj are negatively quadrant dependent for all i. Our main result provides, for TND 0-1 ...
    • Article  

      Power divergence family of tests for categorical time series models 

      Fokianos, Konstantinos (2002)
      A fundamental issue that arises after fitting a regression model is that of testing the goodness of the fit. Our work brings together the power divergence family of goodness of fit tests and regression models for categorical ...
    • Article  

      Random spectral measure for non Gaussian moving averages 

      Baxevani, Anastassia; Podgórski, K. (2017)
      We study the distribution of phases and amplitudes for the spectral representation of weighted moving averages of a general noise measure. The simple independent structure, known for the Gaussian case, and involving Rayleigh ...
    • Conference Object  

      A randomized, O(log w)-depth 2-smoothing network 

      Mavronicolas, Marios; Sauerwald, T. (2009)
      A K-smoothing network is a distributed, low-contention data structure where tokens arrive arbitrarily on w input wires and reach w output wires via their completely asynchronous propagation through the network. The maximum ...
    • Article  

      Randomly cross-linked homopolymer networks: Synthesis by group transfer polymerization in solution and characterization of the aqueous degree of swelling 

      Hadjiyannakou, Stella C.; Yamasaki, E. N.; Patrickios, Costas S. (2001)
      Randomly cross-linked homopolymer networks of 2-(dimethylamino)ethyl methacrylate (DMAEMA) of various average degrees of polymerization (DPs) between cross-links were synthesized by group transfer polymerization (GTP) in ...