The design of the versioning facilities in the Ode object-oriented database system is based on a few powerful concepts that allow implementation of a wide variety of versioning paradigms. These facilities have been cleanly integrated into Ode’s database programming language O++. Object versioning in Ode is orthogonal to type, that is, versioning is an object property and not a type property. Ve...

Professor Thomas Walmsley was appointed to the chair of Anatomy at Queen's in 1919 and held the post until 1951. He graduated in Glasgow in 1912. While lecturing "he combined simplicity of presentation with impressiveness in delivery and held his class spellbound"'. It is said that he had great influence on staff and students alike and was respected by all who came in contact with him; in his t...

Cytotoxic T lymphocytes (CTLs) are immune system cells that are thought to play an important role in controlling HIV infection. We develop a stochastic ODE model of HIV-CTL interaction that extends current deterministic ODE models. Based on this stochastic model, we consider the effect of CTL attack on intrahost HIV lineages assuming that CTLs attack several epitopes with equal strength. In thi...

Web Services are interfaces to a collection of operations that are network-accessible through standardized XML messaging, and whose features are described using standard XML-based languages. Semantic Web Services (SWS) describe semantically the internal structure and the functional/nonfunctional capabilities of the services, facilitating the design and evaluation of SWSs based on that semantic ...

Random ODE and application to statistics. Michail Zak Senior Research Scientist (Emeritus) Jet Propulsion Laboratory California Institute of Technology Pasadena, CA 91109 Abstract. It is demonstrated that any statistics can be represented by an attractor of the solution to the corresponding system of ODE coupled with its Liouville equation. Such a non-Newtonian representation allows one to redu...

Coexistence The special case when all the independent solutions of a linear, T -periodic ODE are T -periodic. Hill’s equation A second order ODE of the form ẍ + p(t)x = 0, with p(t) T -periodic. Instability pockets Finite domains, usually intersections of instability tongues, where the trivial solution of linear, T -periodic ODEs is unstable. Instability tongues Domains in parameter space where...

We suggest multiscale methods for the integration of systems of second-order ordinary differential equations (ODEs) whose solutions include components that oscillate with large frequencies and small amplitudes. The methods do not need to integrate completely the fast oscillations and may employ step-sizes determined by the rate of change of the slow motions of the system. The technique may be u...

We consider a switching system with time delay composed of a finite number of linear delay differential equations (DDEs). Each DDE consists of a sum of a linear ODE part and a linear DDE part. We study two particular cases: (a) all the ODE parts are stable and (b) all the ODE parts are unstable and determine conditions for delay independent stability. For case (a), we extend a standard result o...

This paper considers the stability problem of a linear time invariant system in feedback with a string equation. A new Lyapunov functional candidate is proposed based on the use of augmented states which enriches and encompasses the classical Lyapunov functional proposed in the literature. It results in tractable stability conditions expressed in terms of linear matrix inequalities. This method...

We consider the adaptive strategies applicable to a simple model describing the phase lock of two coupled oscillators. This model has been used to show an instance of failure of the ODE45 RungeKutta-Felberg solver implemented within the MATLAB ODE suite, see [J. D. Skufca. Analysis still matters: a surprising instance of failure of Runge-KuttaFelberg ODE solvers. SIAM Review, 46:729-737, 2004]....