Minimization Strategies for Maximally Parallel Multiset Rewriting Systems

Maximally parallel multiset rewriting systems (MPMRS) give a convenient way to express relations between unstructured objects. The functioning of various computational devices may be expressed in terms of MPMRS (e.g., register machines and many variants of P systems). In particular, this means that MPMRS are computationally complete; however, a direct translation leads to quite a big number of rules. Like for other classes of computationally complete devices, there is a challenge to find a universal system having the smallest number of rules. In this article we present different rule minimization strategies for MPMRS based on encodings and structural transformations. We apply these strategies to the translation of a small universal register machine (Korec, 1996) and we show that there exists a universal MPMRS with 23 rules. Since MPMRS are identical to a restricted variant of P systems with antiport rules, the results we obtained improve previously known results on the number of rules for those systems.Comment: This article is an improved version of [1

Optical simulation of quantum logic

A constructive method for simulating small-scale quantum circuits by use of linear optical devices is presented. It relies on the representation of several quantum bits by a single photon, and on the implementation of universal quantum gates using simple optical components (beam splitters, phase shifters, etc.). This suggests that the optical realization of small quantum networks with present-day quantum optics technology is a reasonable goal. This technique could be useful for demonstrating basic concepts of simple quantum algorithms or error-correction schemes. The optical analog of a nontrivial three-bit quantum circuit is presented as an illustration

Small Universal Spiking Neural P Systems

In search for small universal computing devices of various types, we consider here the case of spiking neural P systems (SN P systems), in two versions: as devices computing functions and as devices generating sets of numbers. We start with the first case and we produce a universal spiking neural P system with 84 neurons. If a slight generalization of the used rules is adopted, namely, we allow rules for producing simultaneously several spikes, then a considerable improvement, to 49 neurons, is obtained. For SN P systems used as generators of sets of numbers, we find a universal system with restricted rules having 76 neurons, and one with extended rules having 50 neurons

New Choice for Small Universal Devices: Symport/Antiport P Systems

Symport/antiport P systems provide a very simple machinery inspired by corresponding operations in the living cell. It turns out that systems of small descriptional complexity are needed to achieve the universality by these systems. This makes them a good candidate for small universal devices replacing register machines for different simulations, especially when a simulating parallel machinery is involved. This article contains survey of these systems and presents different trade-offs between parameters

Extending UPnP for Application Interoperability in a Home Network

The Universal Plug and Play (UPnP) technology offers pervasive communication across heterogeneous devices in a home or small office network. The UPnP specifications are available for devices only to be interoperable together in a home or small office network. This paper proposes an extension of the UPnP technology for application interoperability in a home or small office network. This paper provides an UPnP Application Architecture as an extension to the existing UPnP Device Architecture. This extension enhances the feature of UPnP from device interoperability to application interoperability which enables the applications to discover, control and share data with each other in a home or small office network despite of their device type and operating system. In addition to the UPnP Application Architecture, the UPnP Application Template and UPnP Application Service Template are defined towards the development of UPnP-enabled applications that run on heterogeneous devices in a home or small office network

Are You Still There? - A Lightweight Algorithm to Monitor Node Presence in Self-Configuring Networks

This paper is concerned with the analysis and redesign of a distributed algorithm to monitor the availability of nodes in self-configuring networks. The simple scheme to regularly probe a node ¿ "are you still there?" ¿ may easily lead to over- or underloading. The essence of the algorithm is therefore to automatically adapt the probing frequency. We show that a self-adaptive scheme to control the probe load, originally proposed as an extension to the UPnPTM (Universal Plug and Play) standard, leads to an unfair treatment of nodes: some nodes probe fast while others almost starve. An alternative distributed algorithm is proposed that overcomes this problem and that tolerates highly dynamic network topology changes. The algorithm is very simple and can be implemented on large networks of small computing devices such as mobile phones, PDAs, and so on