Raju Halder

Este artigo apresenta o Ardina, uma infra-estrutura modular de suporte à difusão de informação por intermédio de palmatops. A difusão de informação do Ardina reside na exploração da habitual operação de sincronização ponto-a-ponto entre o palmtop e uma estação de suporte ou entre dois palmtops.

In the last few years, information outsourcing has been a current activity in large companies. Information has become a regular trading commodity. It is a well-known fact that direct mailing companies acquire databases, or other kind of information sources, from other companies with the names and addresses of potential clients. Also, enterprise managers are frequently concerned with the current status and welfare of their clients and suppliers. Commonly, they appeal to specialized external information providers who may, under certain conditions, provide them with specific profiles about such potential commercial partners. In companies with effective means of information processing, it is very probable that such information needs may be directly satisfied from data stored and managed in the company's data warehouse. In this paper, we propose a protocol, based on economic principles, that enables the automatic negotiation of information transfer between the data warehouse systems of different companies. The protocol is designed to be used by a community of intelligent agents that is responsible for ensuring and supporting all the operational tasks related to information outsourcing among companies.

Construction and observation are two basic notions in Computer Science corresponding to precise dual mathematical concepts: those of algebra and coalgebra. This paper introduces a simple coalgebraic model for concurrent processes and discusses its animation in the declarative language Charity. It is argued that the ability to reason in an uniform way about data and behaviour, provides an unifying approach to functional prototyping of software specifications. Keywords: Coalgebraic models, prototyping, higher-order programming.

In this paper we argue that using verification in interactive systems development is more than just checking whether the specification of the system has all the required properties, and that changing the focus from a global specification into partial, property oriented, specifications can provide a number of advantages and make verification actas an aid to decision making. We also present a compiler that allows for the verification of interactor specifications to be done in SMV, as well as a simple case study where verification is used to inform a design decision.

CANopen is a field level communication protocol for industrial automation distributed applications. CANopen offers a powerful set of higher level application layer services which implement an object-oriented distributed environment for simplified system integration. Often, sensors and actuators have to be placed at geographically remote locations, at considerable distances from the processor(s) running a control application. When this is the case, a possible solution is to use an autonomous I/O module, located close to the sensors and actuators, that provides the application with an interface to these devices. The application must be distributed between the remote I/O module and the local processor(s) using a communication network to allow the different parts to cooperate. This work is centred on the development of an I/O module based on the SAB-C167CR-LM chip from SIEMENS. The I/O module makes sensors and actuators accessible via the CAN bus, using the CANopen protocol. The objective is to show that CANopen can be implemented over new hardware platforms, in minimum time, with satisfactory results. It is shown that CANopen provides a systems-integrator-friendly object-oriented environment and that for this reason, the CANopen Communication Profile greatly simplifies the implementation of distributed applications in CAN based systems. Furthermore, CANopen also provides flexible real-time data transfer mechanisms that are able to meet time-critical constraints and, therefore, make CANopen a good solution for distributed control environments.

This work is being developed under the GEIRA project, an EC supported project, under the INTERREG II program. The goal of the GEIRA project is the development of a service to support the publication of multimedia information, with respect to science and technology, cultural resources and environment protection in the of North of Portugal and Galiza (North-west Spain). In this paper we will focus on part of the work being done to provide the museums of this region with tools for data management and methodologies that enable the publication of their data, preferably on the Web.

Most of the existing museums in this region are small with little or no computer-based information support. Only a few have the opportunity to be assisted by a software engineer. Our goal is to get an information system in each museum, running with the minimal external support. It should be as easy as possible to publish information on the Web from that information system. Each museum will have a presence on the Web, as a stand-alone entity.

The aim of project GEIRA is to provide an additional value to the users searching for information. Instead of iterating through a set of institutions, the user can search and browse in a knowledge level above each particular institution. GEIRA will provide that knowledge level, rather than just aggregate a collection of links
in well organized site.

his paper presents a novel architecture for communication protocols that takes advantage of object mobility, allowing applications to specify the behavior of protocols for each individual message. This is achieved by opening the implementation of protocols and letting the application program associate a set of possibly customized meta-objects to every message, separately adapting different aspects of the service provided by the protocol.