A model of P systems with symport / antiport rules is given in terms of hypernets, a generalization of a class of hierarchical Petri nets introduced for modeling mobility inside the nets-within-nets paradigm. The hierarchical structure of a P system is reflected by the associated hypernet, where molecules are modeled by unstructured agents (simple tokens) and membranes by agents. Each agent is ...

Service-oriented computing provides a suitable technological foundation for developing and executing dynamic business processes. However, most current approaches for composition languages and architectures for dynamic process integration do not provide the flexibility and dynamism required by interorganisational evolving environments. In this work, the DENEB platform for the development and exe...

Nested Petri nets (NP-nets) is an extension of the Petri nets formalism within the nets-within-nets approach, allowing to model systems of interacting dynamic agents in a natural way. One of the main problems in verifying of such systems is the State Explosion Problem. To tackle this problem for highly concurrent systems the unfolding method has proved to be very helpful. In this paper we conti...

The structure of moving nonlinear excitations in one-dimensional electronphonon systems is studied semi-phenomenologically by using an effective action in which the width of the nonlinear excitation is treated as a dynamical variable. The effective action can be derived from Su, Schrieffer and Heeger’s model or its continuum version proposed by Takayama, Lin-Liu and Maki with an assumption that...

Because cone outer segments (COS) are now known to be continually renewed, I reexamined COS morphogenesis in retinas of Xenopus tadpoles (prepared by standard histologic techniques and viewed by light and electron microscopy) to clarify how COS incorporate new membrane. I observed that developing COS underwent an unexpected shape change: they were always conical, but their taper (width divided ...

Assuming a first-order auto-regressive model for the auto-correlation structure between observations, in this paper, a transformation method is first employed to eliminate the effect of auto-correlation. Then, a maximum likelihood estimator (MLE) of a step change in the parameters of the transformed model is derived and three separate EWMA control charts are used to monitor the parameters of th...

OBJECTIVE To determine what constitutes normal cervical changes during the second half of pregnancy in parous women delivering at term. DESIGN The study comprises 21 healthy, pregnant parous women who all gave birth at term. They were examined with transvaginal ultrasound every two weeks from 24 gestational weeks until delivery. Cervical length and width were measured. The inner cervical os w...

This paper provides evidence on price rigidity at the product- and firm-level in Norway. A strong within-firm synchronization is found supporting theory of economies scope menu costs. The industry effects are to be small suggesting that firms either have some monopoly power, or a firm’s costs changing their own prices may larger than benefit responding competitors’ changes. These findings poten...