ter verkrijging van de graad van doctor aan de Technische Universiteit Eindhoven, op gezag van de rector magnificus, prof.dr.ir. C.J. van Duijn, voor een commissie aangewezen door het College voor Promoties in het openbaar te verdedigen op maandag 3 oktober 2011 om 16.00 uur door Sonja Georgievska geboren te Strumica, Macedonië Dit proefschrift is goedgekeurd door de promotoren: prof.dr. J.C.M. Baeten en

The interleaving semantics of process calculi considers the replication of process P , written !P , equivalent to P j P j : : : j P as (finitely) many times as needed. This note shows that this equivalence holds no longer when causality is of interest. This is done using a causal semantics

Abstract—We consider two related problems of estimating properties of a collection of point processes: estimating the multiset of parameters of continuous-time Poisson processes based on their activities over a period of time t, and estimating the multiset of activity probabilities of discrete

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them corresponds to a data type. The orthogonality property says in effect that the memory cells are independent: that for any set of values of the memory cells there is a state in which all those values are found in the memory cells. We use the notation x ! y, or x ! y in D when D needs to be specified, to say that x; y is in p. We also call x ! y a move of D, which is technically not compatible with the first use but will always be clear in the context. A history of D, or D-history, is a (finite or infinite) sequence x 1 ; x 2 ; : : : of states such that x i ! x i+1 for each i. A state x is reachable<F31.

We propose a language for testing concurrent processes and examine its strength in terms of the processes that are distinguished by a test. By using probabilistic transition systems as the underlying semantic model, we show how a testing algorithm can distinguish, with a probability arbitrarily

The authors have previously described the use of data path expressions and predecessor automata in debugging concurrent systems. In this paper we examine the relationship of these models to two traditional models of concurrent processes: pomset languages and k-safe Petri net systems. We explore

Information flow security is that aspect of computer security concerned with how confidential information is allowed to flow through a computer system. This is especially subtle when considering processes that are executed concurrently. We consider the notion of Probabilistic Noninterference (PNI

Abstract We provide evidence that the saccadic system can simultaneously program two saccades to different goals. We presented subjects with simple visual search displays in which they were required to make a saccade to an odd-colored target embedded in an array of distractors. When there was strong competition between target and distractor stimuli (due to color priming from previous trials), subjects were more likely to make a saccade to a distractor. Such error saccades were often followed, after a very short inter-saccadic interval ( 10-100 ms), by a second saccade to the target. The brevity of these inter-saccadic intervals suggests that the programming of the two saccades (one to a distractor and one to the target) overlapped in time. Using a saccade-contingent change in the search display, we show that new visual information presented during the initial saccade does not change the goal of the second saccade. This supports the idea that, by the end of the first saccade, programming of the second saccade is already well underway. We also elicited two-saccade responses (similar to those seen in search) using a double-step task, with the first saccade directed to the initial target step and the second saccade directed to the second target step. If the two saccades are programmed in parallel and programming of each saccade is triggered by one of the two target steps, the second saccade should occur at a relatively fixed time after the onset of the second target step, regardless of the timing of the initial saccade. This prediction was confirmed, supporting the idea that the two saccades are programmed in parallel. Finally, we observed that the shortest inter-saccadic intervals typically followed hypometric initial saccades, suggesting that the initial saccade may have been interrupted by the impending second saccade. Using predictions from physiological studies of interrupted saccades, we tested this hypothesis and found that the hypometric initial saccades did not appear to be interrupted in mid-flight. We discuss the significance of our findings for models of the saccadic system.

présence ou non de deadlock. On construit un plongement des CW-complexes globulaires dans les flots et on démontre que deux CW-complexes globulaires sont dihomotopes si et seulement si les flots associés sont dihomotopes. Globular CW-complexes and flows are both geometric models of concurrent processes