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Many widely used specification techniques for information systems are based on a hierarchy of information flow diagrams. A method is introduced which preserves the benefits of these techniques and adds the precision of the Petri net formalism. To this end information flow diagram hierarchies are formalized by notions of net theory. The bottom-level nets of a hierarchy are treated as Petri nets. The behavior model of the information system is the Petri net derived by repeatedly replacing each part of a net by its associated refinement. As a prerequisite for such replacements, the data abstractions relating information flows of different level are specified by a semantic hierarchy data model. The nets in the hierarchy are appended by dynamic counterparts of the abstractions such that a consistent replacement becomes possible. For behavior analysis, the interface behavior of the nets in the hierarchy is analyzed. As formal measure for correct interface behavior the concept of behavior constraints is introduced. The behavior model can be derived in an iterative bottom-up way by first analyzing a net for fulfillment of its associated behavior constraint and afterward integrating it into the next higher level net. [ABSTRACT FROM AUTHOR]

This paper challenges a central tenet of most traditional theories of memory, namely, that memory is stored materially in the brain. Arguing that the storage hypothesis makes any contact with the real past impossible (since the transcendent experience of remembering is presumed to arise from purely present physical processes), it goes on to critique mainstream explanations of memory by noting that their plausibility ultimately rests upon an indefensible homuncular explanation of consciousness. Suggested instead is a phenomenological explanation of remembering rooted in E. Husserl's theory of temporality. This immanent-structural model of time is contrasted with the spatial-linear account of temporality underlying practically all traditional theories of memory. The paper then goes on to give a phenomenological account of the recollective process itself. Finally, the theoretical and research implications of this alternative view of memory for the field of psychology are discussed. [ABSTRACT FROM PUBLISHER]

We study the relationships between a number of behavioural notions that have arisen in the theory of distributed computing. In order to sharpen the under-standing of these relationships we apply the chosen behavioural notions to a basic net-theoretic model of distributed systems called elementary net systems. The behavioural notions that are considered here are trace languages, non-sequential processes, unfoldings and event structures. The relationships between these notions are brought out in the process of establishing that for each elementary net system, the trace language representation of its behaviour agrees in a strong way with the event structure representation of its behaviour. [ABSTRACT FROM AUTHOR]