Synchronizations in Team Automata for Groupware Systems

Team automata have been proposed in Ellis (1997) as a formal framework for modeling both the conceptual and the architectural level of groupware systems. Here we define team automata in a mathematically precise way in terms of component automata which synchronizeon certain executions of actions.At the conceptual level, our model serves as a formal framework in whichbasic groupware notions can be rigorously defined and studied.At the architectural level, team automata can be used as building blocksin the design of groupware systems.     

Controllable transmission of information in excitable media: The 2+ medium

In this paper we address the problem of how to implement directed dispatching of information in homogeneous excitable media. To do this, we surveyed cellular automaton models which reveal spatial oscillating patterns of excitation. Thus we discovered a medium where any element at rest was excited if just two of its nearest neighbours were excited. A medium of this kind, the 2⁺ medium, does not support the spreading of ordinary autowaves, but in its evolution one can find compact movable groups of excited states. Here we demonstrate that such solitary waves with particle-like behaviour will change their velocity vectors as a result of external singular stimulation. Thus they can be used as objects with controllable movement which transmit information in disordered surroundings. The results of this work can be utilised in the design of molecular computers.     

Distributed automata in an assumption-commitment framework

We propose a class of finite state systems of synchronizing distributed processes, where processes make assumptions at local states about the state of other processes in the system. This constrains the global states of the system to those where assumptions made by a process about another are compatible with the commitments offered by the other at that state. We model examples like reliable bit transmission and sequence transmission protocols in this framework and discuss how assumption-commitment structure facilitates compositional design of such protocols. We prove a decomposition theorem which states that every protocol specified globally as a finite state system can be decomposed into such an assumption compatible system. We also present a syntactic characterization of this class using top level parallel composition. The main results here were first reported in an earlier paper (Mohalik & Ramanujam 1998). We thank the anonymous reviewers for detailed comments that helped to improve the presentation     

Adaptive decentralized control under non-uniqueness of the optimal control

We study the problem of decentralization of flow control in packet-switching networks under the isarithmic scheme. An incoming packet enters the network only if there are permits available at the entry port when it arrives. The actions of the controllers refer to the routing of permits in the network and the control variables are the corresponding probabilities. We study the behavior of adaptive algorithms implemented at the controllers to update these probabilities and seek optimal performance. This problem can be stated as a routing problem in a closed queueing network. The centralized version of a learning automation is a general framework presented along with the proof of asymptotic optimality. Decentralization of the controller gives rise to non-uniqueness of the optimal control parameters. Non-uniqueness can be exploited to construct asymptotically optimal learning algorithms that exhibit different behavior. We implement two different algorithms for the parallel operation and discuss their differences. Convergence is established using the weak convergence methodology. In addition to our theoretical results, we illustrate the main results using the flow control problem as a model example and verify the predicted behavior of the two proposed algorithms through computer simulations, including an example of tracking.The work of this author was partially supported by a grant from the Canadian Institute for Telecommunications Research under the NCE program of the Government of Canada, and partially supported by NSERC grant WFA 0139015 and FCAR-Québec grant 95-NC-1375.The work of this author was supported by a grant from the CITR under the NCE program of the Government of Canada.     

Minimal cost one-dimensional linear hybrid cellular automata of degree through 500

This letter is a supplement of the table of the minimal cost one-dimensional linear hybrid cellular automata with the maximum length cycle by Zhang, Miller, and Muzio [IEE Electronics Letters, 27(18):1625–1627, August 1991].This work was supported in part by Research Grants and Postgraduate Scholarships from the Natural Sciences and Engineering Research Council of Canada and by an equipment loan from the Canadian Microelectronics Corporation.     

计算机高速通讯的IPI实现

本文讨论了利用IPI协议实现异种计算机之间高速通讯的技术问题,指出以简化自动机为基础的序列器,以双机应签关系为特征的协议转换和以总线状态循环及操作表为工具的控制逻辑是这个实现技术在物理层上的三个要求。     

Recurrent neural networks and prior knowledge for sequence processing: a constrained nondeterministic approach

The paper focuses on methods for injecting prior knowledge into adaptive recurrent networks for sequence processing. In order to increase the flexibility needed for specifying partially known rules, a nondeterministic approach for modelling domain knowledge is proposed. The algorithms presented in the paper allow time-warping nondeterministic automata to be mapped into recurrent architectures with first-order connections. These kinds of automata are suitable for modeling temporal scale distortions in data such as acoustic sequences occurring in problems of speech recognition. The algorithms output a recurrent architecture and a feasible region in the connection weight space. It is demonstrated that, as long as the weights are constrained into the feasible region, the nondeterministic rules introduced using prior knowledge are not destroyed by learning. The paper focuses primarily on architectural issues, but the proposed method allows the connection weights to be subsequently tuned to adapt the behavior of the network to data.     

Macroscopic isotropy of two- and three-dimensional elastic lattice models

Particle methods such as the meso-particle method or the method of movable cellular automata provide new possibilities for the simulation of wear, mass-transfer, plastic deformation and melting processes. One crucial point, however, is to ensure that in the continuum limit macroscopic isotropy is guaranteed. We show how this can be done in two- and three-dimensional lattices.     

MINIMAL VALID AUTOMATA OF SAMPLE SEQUENCES FOR DISCRETE EVENT SYSTEMS

Minimal valid automata (MVA) refer to valid automata models that fit a given input‐output sequence sample from a Mealy machine model. They are minimal in the sense that the number of states in these automata is minimal. Critical to system identification problems of discrete event systems, MVA can be considered as a special case of the minimization problem for incompletely specified sequential machine (ISSM). While the minimization of ISSM in general is an NP‐complete problem, various approaches have been proposed to alleviate computational requirement by taking special structural properties of the ISSM at hand. In essence, MVA is to find the minimal realization of an ISSM where each state only has one subsequent state transition defined. This paper presents an algorithm that divides the minimization process into two phases: first to give a reduced machine for the equivalent sequential machine, and then to minimize the reduced machine into minimal realization solutions. An example with comprehensive coverage on how the associated minimal valid automata are derived is also included.