• Report  

      Algebraic and Geometric Approach in Function Problem Solving 

      Mousoulides,Nicholas G.; Gagatsis, Athanasios (International Group for the Psychology of Mathematics Education, 2004)
      This study explores students algebraic and geometric approach in solving tasks in functions and the relation of these approaches with complex geometric problem solving. Data were obtained from 95 sophomore pre-service ...
    • 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 ...
    • Article  

      Algebraic properties of evolution partial differential equations modelling prices of commodities 

      Sophocleous, Christodoulos; Leach, Peter G. L.; Andriopoulos, Konstantinos (2008)
      Schwartz (J. Finance 1997
    • Article  

      Algebraic solution of the Stein-Stein model for stochastic volatility 

      Sophocleous, Christodoulos; O'Hara, John G.; Leach, Peter G. L. (2011)
      We provide an algebraic approach to the solution of the Stein-Stein model for stochastic volatility which arises in the determination of the Radon-Nikodym density of the minimal entropy of the martingale measure. We extend ...
    • Article  

      Are registers of representations and problem solving processes on functions compartmentalized in students' thinking? 

      Gagatsis, Athanasios; Elia, Iliada; Mousoulides,Nicholas G. (2006)
      The purpose of the present study is twofold: first, to review and summarize previous research on the compartmentalization of different registers of representations and problem solving approaches related to the concept of ...
    • Article  

      The ASBM-SA turbulence closure: Taking advantage of structure-based modeling in current engineering CFD codes 

      Panagiotou, C. F.; Kassinos, Stavros C.; Aupoix, B. (2015)
      Structure-based turbulence models (SBM) carry information about the turbulence structure that is needed for the prediction of complex non-equilibrium flows. SBM have been successfully used to predict a number of canonical ...
    • Article  

      Bogoyavlensky-Volterra and Birkhoff integrable systems 

      Damianou, Pantelis A.; Kouzaris, S. P. (2004)
      In this paper we examine an interesting connection between the generalized Volterra lattices of Bogoyavlensky and a special case of an integrable system defined by Sklyanin. The Sklyanin system happens to be one of the ...
    • Article  

      Coleff-Herrera Currents Revisited 

      Vidras, Alekos; Yger, A. (2012)
      In the present paper, we describe the recent approach to residue currents by Andersson, Björk, and Samuelsson (Andersson in Ann. Fac. Sci. ToulouseMath. Sér. 18(4):651-661, 2009
    • Article  

      The cost of concurrent, low-contention Read&Modify&Write 

      Busch, Costas; Mavronicolas, Marios; Spirakis, Paul G. (2005)
      The possibility or impossibility and the corresponding costs of devising concurrent, low-contention implementations of atomic Read&Modify&Write (or RMW) operations in a distributed system were addressed. A natural class ...
    • Conference Object  

      Directly computable L2 and Lx performance bounds for Morse's dynamic certainty equivalence adaptive controller 

      Datta, Aniruddha; Ioannou, Petros A. (1995)
      In this paper we consider a model reference adaptive control scheme where the classical error augmentation and standard tuning error normalization are avoided through the use of Morse's high order tuner. We consider the ...
    • Article  

      Eight-Dimensional Quantum Hall Effect and "Octonions" 

      Bernevig, B. A.; Hu, J.; Toumbas, Nicolaos K.; Zhang, S. -C (2003)
      A generalization of the quantum Hall effect (QHE) where particles move in an eight-dimensional space under an SO(8) gauge field was constructed. A nonrelativistic Hamiltonian for particles moving on the S8 in the presence ...
    • Article  

      Enhanced group classification of Benjamin–Bona–Mahony–Burgers equations 

      Vaneeva, Olena O.; Pošta, Severin; Sophocleous, Christodoulos (2017)
      A class of the Benjamin–Bona–Mahony–Burgers (BBMB) equations with time-dependent coefficients is investigated with the Lie symmetry point of view. The set of admissible transformations of the class is described exhaustively. ...
    • Article  

      Enhanced group classification of Gardner equations with time-dependent coefficients 

      Vaneeva, Olena O.; Kuriksha, O.; Sophocleous, Christodoulos (2015)
      We classify the Lie symmetries of variable coefficient Gardner equations (called also the combined KdV-mKdV equations). In contrast to the particular results presented in Molati and Ramollo (2012) we perform the exhaustive ...
    • Article  

      A Family of Resource-Bound Real-Time Process Algebras 

      Lee, I.; Philippou, Anna; Sokolsky, O. (2006)
      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  

      Fault-tolerant computation in groups and semigroups: Applications to automata, dynamic systems and Petri nets 

      Hadjicostis, Christoforos N.; Verghese, G. C. (2002)
      The traditional approach to fault-tolerant computation has been via modular hardware redundancy. Although universal and simple, modular redundancy is inherently expensive and inefficient. By exploiting particular structural ...
    • Article  

      Generalized Lotka - Volterra systems connected with simple Lie algebras 

      Charalambides, Stelios A.; Damianou, Pantelis A.; Evripidou, Charalambos A. (2015)
      We devise a new method for producing Hamiltonian systems by constructing the corresponding Lax pairs. This is achieved by considering a larger subset of the positive roots than the simple roots of the root system of a ...
    • Article  

      Group classification of systems of diffusion equations 

      Kontogiorgis, Stavros; Sophocleous, Christodoulos (2017)
      Group classification of a class of systems of diffusion equations is carried out. Arbitrary elements that appear in the system depend on two variables. All forms of the arbitrary elements that provide additional Lie ...
    • Article  

      Hiding resources that can fail: An axiomatic perspective 

      Philippou, Anna; Sokolsky, O.; Lee, I.; Cleaveland, R.; Smolka, S. A. (2001)
      In earlier work, we presented a process algebra, PACSR, that uses a notion of resource failure to capture probabilistic behavior in reactive systems. PACSR also supports an operator for resource hiding. In this paper, we ...
    • Conference Object  

      How many attackers can selfish defenders catch? 

      Mavronicolas, Marios; Monien, Burkhard; Lesta, Vicky Papadopoulou (2008)
      In a distributed system with attacks and defenses, an economic investment in defense mechanisms aims at increasing the degree of system protection against the attacks. We study such investments in the selfish setting, where ...
    • Conference Object  

      Information states in optimal control of stochastic systems: A Lie algebraic theoretic approach 

      Charalambous, Charalambos D.; Elliott, Robert J. (IEEE, 1997)
      In this paper we introduce the sufficient statistic algebra which is responsible for propagating the sufficient statistic, or information state, in the optimal control of stochastic systems. Using a Lie algebraic formulation, ...