The Synchronous Approach to Designing Reactive Systems

Editor: Abstract. Synchronous programming is available through several formally defined languages having very different characteristics: ESTEREL is imperative, while LUSTRE and SIGNAL are declarative in style; STATECHARTS and ARGOS are graphical languages that allow one to program by constructing hierarchical automata. Our motivation for taking the synchronous design paradigm further, integrating imperative, declarative (or dataflow), and graphical programming styles, is that real systems typically have components that match each of these profiles. This paper motivates our interest in the mixed language programming of embedded software around a number of examples, and sketches the semantical foundation of the SYNCHRONIE toolset which ensures a coherent computational model. This toolset supports a design trajectory that incorporates rapid prototyping and systematic testing for early design validation, an object oriented development methodology for long term software management, and formal verification at the level of automatically generated object code

Foerderungsschwerpunkt Mikrosystemtechnik: Aus- und Bewertung der Verbundmassnahme Zweiter Erfahrungsbericht

The essential results of the evaluation of the joint project micro-system technique after three years of support are, that the joint is well accepted by industry and research. Small and medium enterprises show a strong interest for the joint research of micro-system technique. In particular, they have the following aims: the diversification in new technology fields, the improvement of an estimation of the potential of micro techniques and the access to external R + D resources and technology know-howSIGLEAvailable from TIB Hannover: FR 4808 / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekBundesministerium fuer Forschung und Technologie (BMFT), Bonn (Germany)DEGerman

GMD - Forschungszentrum Informationstechnik. Geschaeftsbericht 1998

Available from TIB Hannover / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

Spezifikation und Verifikation eines 'Separation of Duty'-Szenarios als verbindliche Telekooperation im Sinne des Gleichgewichtsmodells

The balance model assures non-repudiation of telecooperation in open systems. This security model, introduced in 1993 by Dr. Ruediger Grimm, is the last step in a series of proposed security models. It addresses the problem that integrity of data in open systems cannot be assured by a third party. In contrast to 'conventional' security models that are limited to locking out danger, the balance model extends this view to the handling of dangerous situations. An important step towards this 'new' view of IT-security was the Clark/Wilson security model, introduced in 1987. As one of the first models, it makes use of a human as an interpretation instance using the classic four-eyes-principle Separation of duty. This diploma thesis is based on the balance model and describes a 'Separation of duty' - telecooperation, which is formally specified with product nets and verified with methods based on formal language theory. These methods are supported by a tool, the SH-verification tool. The four-eyes-principle is exemplified by an everyday provision-application within a company. This example consists of a two-partner cooperation, in which the 'manager' delegates the decision about a provision-application to the two cooperation partners 'head of department' and 'auditor'. An order is placed only if both partners, head of department and auditor, agree to the provision. According to the balance model, the cooperation partners control each other through collection of proofs and administration of the partner's obligations. In general, each change in the state of obligation is compensated by a proof for the favored cooperation partner. Using the formal methods of the SH-verification tool, a number of properties of the cooperation system have been verified. At first it is shown that the cooperation partners work together according to the cooperation specification and the cooperation principle. As a main aspect of the balance model, it is proved that the balance between state of obligation and proofs is kept during the cooperation at any time. In addition, a special kind of liveness property is shown, namely the property that a new provision-application can always be started. The idea of simple homomorphisms - which is fundamental for the verification by the SH-verification tool - is explained using an incorrect specification. Finally, an example for an irregular ending of the cooperation - by fraud - is specified and verified. (orig.)SIGLEAvailable from TIB Hannover: RR 8957(1998,21) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman

An Approach For Managing Highly Configurable Operating Systems

Introduction Building a small and well adapted operating system for a particular problem class is one thing, building the same for a wide range of problems another. Embedded systems e.g. are becoming more and more complex, and the assembly style programming which is quite usual in this context does not allow a quick adaption of old sources to a new problem which is only slightly different. Similar problems arise in massively parallel systems. The operating system should support every application optimal i.e. have no feature that is not used by the running application. Different application have different needs, one uses only a single task, other are doing full multitasking. All these operating systems have so much in common, that it pays off to share those common parts. Both kinds of adaption are solvable through use of object-oriented designs. But object-orientation is often said to bear too much overhead to be practical for systems with very limited resources. We claim tha

Beschleunigung der Industriellen Diffusion in der Mikrosystemtechnik (BIMST) Abschlussbericht

Available from TIB Hannover: F02B423 / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEBundesministerium fuer Bildung, Wissenschaft, Forschung und Technologie, Bonn (Germany)DEGerman

Entwicklungen in der Mikrosystemtechnik fuer die Medizin Ergebnisse, Erfahrungen und Perspektiven aus laufenden Kooperationsprojekten. Tagungsbericht

SIGLEAvailable from TIB Hannover: RR 3532(30) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman