João Filho

This paper presents a conceptual design model for user interfaces (MASS1) and a general formalism for dialogue specification (Interaction Scripts) which are the most important components of an approach to the methodological, iterative design of Interactive Systems from formal, model-based specification of both the application and the User Interface (UI).
This approach allows the integration of both dialogue and application semantics from the beginning of the design process, by using prototypes derived from both specifications. Assuming that all the application semantics is available at early design stages, the MASS model defines a set of guidelines that will enforce the designer to create user interfaces that will present a prophylactic instead of the usual therapeutic behaviour. By a prophylactic behaviour it is meant, metaphorically, that the UI will exhibit a behaviour that prevents and avoids both syntactic and semantic user errors, in contrast with the most usual therapeutic, or error recovery, behaviour.
The dialogue specification formalism(Interaction Scripts) despite being general, in the sense that it may be applied to the specification of any kind of dialogue, is specially suited to the specification of UIs with the behaviour prescribed by the MASS design model. In addition, it is independent from concrete environment details, therefore allowing for different implementations of the same specification, that is, different looks and feels. The operational semantics of the Interaction Script notation is also presented in terms of Petri-Nets that are automatically generated from the Interaction Script specification of the dialogue controller.

Although WWW browsers such as Netscape already offer some support for operation under low bandwidth connections, this is still unsuited for mobile environments. In contrast to fixed networks, here connection time is usually expensive and thus clients cannot afford long sessions. MobiScape uses the proxy interface present on modern navigation tools. It intercepts the HTTP data flow, compresses it, and applies caching, hoarding and prefetching policies to both the mobile host and its support station. The Support Station proxy keeps a given subset of remote documents in local store and up-to-date; occasionally it will prefetch. The Mobile Host proxy will hoard according to its profile, trying to minimize the need for a connection. The system also maximizes the use of the cache by using dynamic caching policies. No modifications were made to the existing HTTP server, proxies or browsers.

Under normal circumstances, NFS provides transparent access to remote file systems. Evertheless,a failure on a single file server compromises the operation of all clients, and thus various replication schemes have been devised to increase file system availability.The approach described in this paper is lightweight in the sense that it strives to make no changes to the NFS protocol nor to the standard NFS client and server code. Rather,a thin layer is introduced between the clients and the original server daemons, which intercepts all NFS requests and propagates the updates to the replicas. Replication is hidden under a primary-secondary update policy and an improved automounter. If the primary server fails, the automounters elect a new primary and remount the relevant file systems. Secondary server failures remain unnoticed by the clients. A prototype version is operational and preliminary result sunder the Andrew benchmark are presented.The gures obtained show that while read overhead is negligible, the performance of updates is severely impaired by the naive synchronous multi-server write operation.

Apresenta-se neste artigo uma arquitectura software destinada a fornecer o suporte tecnológico ao desenvolvimento de Interfaces Utilizador no enquadramento de uma metodologia rigorosa para o desenvolvimento de Sistemas Interactivos.
Assim, partindo da especificação formal da camada aplicativa, usando modelos matemáticos, a metodologia visa a sistematização do processo de construção do sistema interactivo, segundo princípios que têm por objectivo a criação de interfaces de qualidade dado o seu grau de assistência ao utilizador, dadas as suas características preventivas de erros e finalmente dada a sua sensibilidade contectual.
O sistema apresentado, GAMA-X, oferece uma arquitectura de apoio ao desenvolvimento sistemático e semi-automático deste tipo de interfaces, incorporando ferramentas que apoiam os diferentes passos de desenvolvimento.
Apresenta-se neste artigo em maior detalhe a composição do GAMA-X, com relevo para os módulos mais ligados à IU, bem como a linguagem de especificação do controlador de diálogo.
Referem-se ainda questões relacionadas com a camada de apresentação e com a comunicação entre os diferentes módulos.

This paper starts by present the research landscape of the vulnerabilities of cyberspace, then makes a classification of the cyber vulnerabilities identified in literature, and at the end proposes a cybersecurity framework to tackle those cyberspace vulnerabilities. The proposed framework is grounded in three main pillars: a cybersecurity governance model, cybersecurity capabilities, and cybersecurity best practices. The research methodology used to conduct this study is based on a quantitative and qualitative analyses of the literature on the field. The paper concludes that the framework can be a useful tool for preventing and mitigating cyber-attacks in public and private organizations.