Browsing by Subject "Algebra"

Now showing items 21-39 of 39

    • Conference Object  

      Lie algebraic methods in optimal control of stochastic systems with exponential-of-integral sample cost: Examples 

      Charalambous, Charalambos D. (1998)
      The optimal control of partially observed stochastic systems with exponential-of-integral-sample cost is considered. The concept of sufficient statistic algebra is introduced to construct finite-dimensional controllers. ...
    • Article  

      Lie symmetries of generalized Burgers equations: application to boundary-value problems 

      Vaneeva, Olena O.; Sophocleous, Christodoulos; Leach, Peter G. L. (2015)
      There exist several approaches exploiting Lie symmetries in the reduction of boundary-value problems for partial differential equations modelling real-world phenomena to those problems for ordinary differential equations. ...
    • Doctoral Thesis  

      Multiple Hamiltonian structures for Volterra and Toda Lattices 

      Kouzaris, Stelios (Πανεπιστήμιο Κύπρου, Σχολή Θετικών και Εφαρμοσμένων Επιστημών/ University of Cyprus, Faculty of Pure and Applied Sciences, 2001)
      Η διατριβή χωρίζεται σε δύο μέρη. Στο πρώτο μέρος μελετούμε τα ολοκληρώσιμα συστήματα που κατασκεύαστηκαν από τον Bogoyavlensky το 1988. Αυτά τα συστήματα συνδέονται με απλές Lie άλγεβρες και γενικεύουν το καλά γνωστό ...
    • 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 ...
    • Article  

      Numerical solutions of boundary value problems for variable coefficient generalized KdV equations using Lie symmetries 

      Vaneeva, Olena O.; Papanicolaou, N. C.; Christou, Marios Andreas; Sophocleous, Christodoulos (2014)
      The exhaustive group classification of a class of variable coefficient generalized KdV equations is presented, which completes and enhances results existing in the literature. Lie symmetries are used for solving an initial ...
    • Conference Object  

      On optimal performance for linear time-varying systems 

      Djouadi, S. M.; Charalambous, Charalambos D. (2004)
      In this paper we consider the optimal disturbance attenuation problem and robustness for linear time-varying (LTV) systems. This problem corresponds to the standard optimal H ∞ problem for LTI systems. The problem is ...
    • Article  

      PADS: An approach to modeling resource demand and supply for the formal analysis of hierarchical scheduling 

      Philippou, Anna; Lee, I.; Sokolsky, O. (2012)
      As real-time embedded systems become more complex, resource partitioning is increasingly used to guarantee real-time performance. Recently, several compositional frameworks of resource partitioning have been proposed using ...
    • Doctoral Thesis  Open Access

      Perturbation of zeros of entire functions of exponential type 

      Zikkos, Elias D. (Πανεπιστήμιο Κύπρου, Σχολή Θετικών και Εφαρμοσμένων Επιστημών / University of Cyprus, Faculty of Pure and Applied Sciences, 2004)
      Η διδακτορική διατριβή χωρίζεται σε δύο μέρη. Στο πρώτο μέρος βρίσκουμε νέα κριτήρια ώστε δύο ακολουθίες μιγαδικών αριθμών να έχουν το ίδιο πλεόνασμα στον χώρο . Στο δεύτερο μέρος επεκτείνουμε ...
    • Article  

      Probabilistic resource failure in real-time process algebra 

      Philippou, Anna; Cleaveland, R.; Lee, I.; Smolka, S.; Sokolsky, O. (1998)
      PACSR, a probabilistic extension of the real-time process algebra ACSR, is presented. The extension is built upon a novel treatment of the notion of a resource. In ACSR, resources are used to model contention in accessing ...
    • Article  

      A process algebraic framework for modeling resource demand and supply 

      Philippou, Anna; Lee, I.; Sokolsky, O.; Choi, J. -Y (2010)
      As real-time embedded systems become more complex, resource partitioning is increasingly used to guarantee real-time performance. Recently, several compositional frameworks of resource partitioning have been proposed using ...
    • Conference Object  

      A relationally complete visual query language for heterogeneous dAta Sources and pervasive querying 

      Polyviou, S.; Samaras, George S.; Evripidou, Paraskevas (2005)
      In this paper we introduce and formally define Query by Browsing (QBB), a scalable, relationally complete visual query language based on the desktop user interface paradigm and tuple relational calculus that allows the ...
    • Article  

      Resources in process algebra 

      Lee, I.; Philippou, Anna; Sokolsky, O. (2007)
      The Algebra of Communicating Shared Resources (ACSR) is a timed process algebra which extends classical process algebras with the notion of a resource. It takes the view that the timing behavior of a real-time system depends ...
    • Article  

      Similarity reductions of the (1 + 3)-dimensional Burgers equation 

      Christou, Marios Andreas; Ivanova, Nataliya M.; Sophocleous, Christodoulos (2009)
      We consider the (1 + 3)-dimensional Burgers equation ut = uxx + uyy + uzz + uux which has considerable interest in mathematical physics. We complete the list of similarity reductions that are obtained from the Lie symmetries ...
    • Article  

      A simplified structure-based model using standard turbulence scale equations: computation of rotating wall-bounded flows 

      Kassinos, Stavros C.; Langer, C. A.; Kalitzin, G.; Iaccarino, G. (2006)
      Two linear eddy-viscosity models, the v2-f and k-ω models, have been combined with an algebraic structure-based algorithm for the evaluation of the Reynolds stresses. This closure was originally designed as an integral ...
    • Article  

      So (p, q) Toda systems 

      Charalambides, Stelios A.; Damianou, Pantelis A. (2013)
      We define an integrable Hamiltonian system of Toda type associated with the real Lie algebra so(p,q). As usual there exist a periodic and a non-periodic version. We construct, using the root space, two Lax pair representations ...
    • Conference Object  

      A sufficient condition for decentralized non-cooperative stochastic differential games and relations to mean field games 

      Charalambous, Charalambos D. (Institute of Electrical and Electronics Engineers Inc., 2015)
      In this paper we use martingale techniques to derive a sufficient condition for existence of decentralized strategies in non-cooperative stochastic differential games. The sufficient condition is given by decentralized ...
    • Conference Object  

      Symbolic schedulability analysis of real-time systems 

      Kwak, Hee-Hwan; Lee, Insup; Philippou, Anna; Choi, Jin-Young; Sokolsky, Oleg (IEEE, 1998)
      We propose a unifying method for analysis of scheduling problems in real-time systems. The method is based on ACSR-VP, a real-time process algebra with value-passing capabilities. We use ACSR-VP to describe an instance of ...
    • Article  

      Symmetry and singularity analyses of some equations of the fifth and sixth order in the spatial variable arising from the modelling of thin films 

      Charalambous, Kyriakos; Sophocleous, Christodoulos; Leach, Peter G. L. (2013)
      In the modelling of the flow of thin films higher-order derivatives in the spatial variable are introduced to model nonlinear effects. We examine nonlinear evolution equations of the fifth and sixth orders in the spatial ...
    • Article  

      Symmetry properties for a generalised thin film equation 

      Charalambous, Kyriakos; Sophocleous, Christodoulos (2013)
      Symmetry properties are presented for a fourth-order parabolic equation written in conservation form. It was introduced in the literature as a generalisation of the fourth-order thin film equation. We derive equivalence ...