The results of the first irradiation tests of newly designed silicon microstrip detectors performed with 21 MeV protons at the Max-Planck-Institut in Heidelberg are presented. The detectors were ...developed and produced by the semiconductor laboratory of the Max-Planck-Institut in Munich. Novel guard ring structures allow operation of the detectors at voltages exceeding 300 V.
We consider the problem of finding the mask value of the supremal normal sublanguage L/sub R/ of some given language L. We describe a straightforward algorithmic solution that can be applied to ...existing off-line procedures for determining the supremal controllable and normal sublanguage of L and that does not require an explicit calculation of L/sub R/. This problem is fundamental because it is related to the supervisory control problem under partial observation. Our algorithm applies only to closed languages.< >
This paper presents a new paradigm for designing reactive systems. It combines the use of formal methods widely recognized in software engineering and synthesis procedures developed within the ...framework of the
Supervisory Control Theory for discrete event systems. It promotes design exploration by means of a synthesis approach with the sole aim of producing reliable reactive systems. The adoption of these particular synthesis procedures is, however, not sufficient to achieve this objective, because of scalability and computational complexity issues. To circumvent these difficulties, this paper suggests two extensions with respect to conventional synthesis procedures. The first one concerns the representation of reactive programs by attributed controllers. This requires that the process to be controlled must be described not only in terms of controllable active components but also in terms of uncontrollable passive components by using timed transition graphs and algebraic specifications, respectively. The second one involves abstraction and equational reasoning to take into account the use of strongly typed objects. This requires various kinds of transformation applied to the original problem specification as well as to intermediate solutions.
The effects of a thrombin active-site inhibitor on arterial and venous thrombosis, and thrombin-induced thrombocytopenia were determined in anesthetized rats. Desamino D-Phe-Pro-Arg-aldehyde (BMY ...44621) was administered before experimental intervention as a loading i.v. dose plus continuous i.v. infusion. Carotid artery thrombosis was produced by transmural vessel injury and vena cava thrombosis was produced by partial stasis of blood flow combined with endothelial injury. Thrombocytopenia was induced by an i.v. injection of human alpha-thrombin. BMY 44621 inhibited arterial and venous thrombosis in a dose-dependent manner. Its threshold antithrombotic dose for venous thrombosis was half of that for arterial thrombosis. Maximum reductions in thrombus weight were greater for venous (> 90%) compared to arterial (57%) thrombosis and correlated with 2-and 9-fold prolongation of ex vivo thrombin clotting time, respectively. A 40% reduction in platelet counts induced by thrombin injection was abolished by the threshold dose of BMY 44621 for inhibiting venous thrombosis. These experiments demonstrate that thrombin's active-site is an effective target for inhibiting venous and arterial thrombosis, although venous thrombosis is more sensitive to this therapeutic strategy than arterial thrombosis.
This paper presents a simple and flexible on-line synthesis algorithm that derives the optimal controller for a given environment. It consists of finding the greatest possible number of admissible ...event sequences of a discrete-event system with respect to a requirements specification. It generates and explores the state space on-the-fly and uses a control-directed backtracking technique. Compared to a previous algorithm of Wonham and Ramadge, our algorithm does not require explicit storage of the entire work space and backtracks on paths of arbitrary length to prune the search space more efficiently. This paper also discusses an implementation of our algorithm and includes an evaluation of its performance on a variety of problems.
During the last 10 years, many organizations have invested resources and energy in order to be rated at the highest level as possible according to some maturity models for software development. Since ...measures play an important role in these models, it is essential that CASE tools offer facilities to automatically measure the sizes of various documents produced using them. This paper introduces a tool, called ucROSE, that automatically measures the functional software size, as defined by the COSMIC-FFP method, for Rational Rose RealTime models. ucROSE streamlines the measurement process, ensuring repeatability and consistency in measurement while reducing measurement cost. It is the first tool to address automatic measurement of COSMIC-FFP and it can be integrated into the Rational Rose RealTime toolset. PUBLICATION ABSTRACT
This paper describes a formal method for specifying the observable (external) behavior of information systems using a process algebra and input-output traces. Its notation is mainly based on the ...entity concept, borrowed from the Jackson System Development method, and integrated with the requirements class diagram to represent data structures and associations. The specification process promotes modular and incremental description of the behavior of each entity through process abstraction, entity type patterns, and entity attribute function patterns. Valid system input traces result from the composition of entity traces by using parallel composition operations. The association between input traces and outputs through an input-output relation completes the specification process.
This paper describes a technique to construct reachability graphs from replicated structures. This new technique can be combined with an off-line synthesis algorithm in order to automatically ...generate nonblocking supervisors in closed form. Replicated structures arise from the modeling of similar processes and similar cases, which are components of parameterized discrete event systems and workflow processes, respectively. The analysis and control of such systems require a state space exploration. The proposed approach weakens the state explosion problem by using symbols and expressions instead of numerical values in markings, which makes it possible to obtain supervisors with explicit conditions in their control actions.
