Computation of the winding number diffusion rate due to the cosmological sphaleron

A detailed quantitative analysis of the transition process mediated by a sphaleron type non-Abelian gauge field configuration in a static Einstein universe is carried out. By examining spectra of the fluctuation operators and applying the zeta function regularization scheme, a closed analytical expression for the transition rate at the one-loop level is derived. This is a unique example of an exact solution for a sphaleron model in $3+1$ spacetime dimensions.Comment: Some style corrections suggested by the referee are introduced (mainly in Sec.II), one reference added. To appear in Phys.Rev.D 29 pages, LaTeX, 3 Postscript figures, uses epsf.st

Hardware/Software Co-Design of Complex Embedded Systems: An Approach Using Efficient Process Models, Multiple Formalism Specification and Validation via Co-Simulation

This paper presents a hardware/software co-design approachwhere different specification languages can be used in parallel, allowingeffective system co-modeling. The proposed methodology introduces a processmodel that extends the traditional spiral model so as to reflect the designneeds of modern embedded systems. The methodology is supported by an advancedtoolset that allows co-modeling and co-simulation using SDL, Statecharts andMATRIXX, and interactive hardware/software partitioning. The effectivenessof the proposed approach is exhibited through two applicati on examples: thedesign of a car window lift mechanism, and the design of a MAC layer protocolfor wireless ATM networks

A hardware/software co-design methodology for embedded telecommunication systems

International audienceThe current paper presents an integrated co-design methodology for embedded telecommunication systems, starting from high-level system modelling down to system implementation. The proposed co-design methodology uses a system specification captured in UML language, translates at a simulatable SDL description used as input to the COSMOS toolset for the generation of a virtual hardware/software prototype. The system's partitioning is achieved interactively in a semi-automatic way, based on COSMOS and its underlying SOLAR format, producing C and VHDL descriptions for the implementation of software and hardware parts respectively. For the co-simulation, synthesis and system implementation parts of the proposed methodology, the CoWare tool has been employed using as front end the generated C and VHDL descriptions produced by COSMOS. The effectiveness of the proposed co-design approach is demonstrated through its application for the design and implementation of the Medium Access Control (MAC) layer and the RF I/F part of the Physical (PHY) layer of the DECT protocol stack

Hardware/software co-design of embedded systems using multiple formalisms for application development

International audienceIn this paper a co-design methodology based on multiformalism modeling is presented. It defines a platform that integrates different notations and, the necessary mechanisms to handle different in nature models in a coherent way. The supported formalisms cover a wide area of application domains, allowing the designer to select the notations that are mostly appropriate for his application. The proposed co-design development cycle provides a full blown path from system specification to a virtual prototype of the system under construction. Its effectiveness is depicted through its use for the design and implementation of a MAC layer protocol, named MASCARA, for providing ATM QoS over wireless connections

Extending the MaSE Methodology for the Development of Embedded Real-Time Systems

Abstract. Embedded real-time systems play an important role in various application areas like plant automation, product automation or car electronics. In recent years, a considerable growth in the functionality has been observed. At the same time, expectations on systems’ flexibility at runtime are growing steadily. The agent-oriented software engineering approach is well suited for the development of decentralised, complex software systems with high flexibility. A number of software engineering methodologies have been introduced for developing agent-oriented systems. However, none of the existing methodologies is intended for the development of embedded real-time systems. This work presents concepts that extend the Multi-agent Systems Engineering (MaSE) methodology for the development of agent-oriented embedded real-time systems. The proposed concepts have been integrated in the traditional engineering process of MasE and evaluated by applying the extended process to the development of a flexible agent-oriented embedded system for the control of an elevator model. Keywords: Agent-Oriented Software Development, Real-Time Systems, Embedded System