Compiling Path Expressions into VLSI Circuits

Path expressions were originally proposed by Campbell and Haberman [2] as a mechanism for process synchronization at the monitor level in software.. Not unexpectedly, they also provided notation for specifying the behavior of asynchronous circuits. Motivated by these potential applications, we investigate how to directly translate path expressions into hardware. Our implementation is complicated in the case of multiple path expressions by the need for synchronization on event names that are common to more than one path. However, since events are inherently asynchronous in our model, all of our circuits must be self-timed. Nevertheless, the circuits produced by our construction have area proportional to N*log(N) where N is the total length of the multiple path expression under consideration. This bound holds regardless of the number of individual paths or the degree of synchronization between paths. Furthermore, if the structure of the path expression allows partitioning. the circuit can be layed out in a distributed fashion without additional area overhead

Equivalence checking for weak bi-Kleene algebra

Pomset automata are an operational model of weak bi-Kleene algebra, which describes programs that can fork an execution into parallel threads, upon completion of which execution can join to resume as a single thread. We characterize a fragment of pomset automata that admits a decision procedure for language equivalence. Furthermore, we prove that this fragment corresponds precisely to series-rational expressions, i.e., rational expressions with an additional operator for bounded parallelism. As a consequence, we obtain a new proof that equivalence of series-rational expressions is decidable

Higher-level Knowledge, Rational and Social Levels Constraints of the Common Model of the Mind

We present the input to the discussion about the computational framework known as Common Model of Cognition (CMC) from the working group dealing with the knowledge/rational/social levels. In particular, we present a list of the higher level constraints that should be addressed within such a general framework

The Skin of Spectral Time in Grisey's Le Noir de l’Étoile

Following the aesthetics of pure continuity in the late 1970s, Grisey moved on to compose for unpitched percussion in Tempus ex Machina, focusing on pure rhythm. Shortly afterwards he elaborated on his theory of temporality in a talk and article of the same title; one decade later, he included Tempus as the first movement of Le Noir de l’Étoile. Grisey insisted on the significance of the perception of musical time, of the skin of time – as opposed to its skeleton or flesh. This article puts forward an interpretation of Grisey's thinking of temporality, drawing on concepts from French philosophy. It further provides an analysis of two sections of Le Noir, tracing these concepts in the structuring of musical time, with a view to providing a possible direction towards a re-definition of spectral time