Abstract
A interface de utilizador é essencial para o sucesso de uma aplicação, ora a sua implementação requer tempo e esforço. Metodologias baseadas em modelos suportadas por uma geração automática têm sido propostas como solução para reduzir os custos de desenvolvimento. No entanto, um elevado nível de automação nestas abordagens requer o uso de modelos detalhados da interface, originando complicações. Por um lado, esta perspetiva é contrária a uma conceção baseada no progressivo refinamento de mockups, típica do desenvolvimento de interfaces. Por outro lado, obriga uma distinção entre os modelos utilizados na lógica de negócio e na interface. Este artigo propõe uma abordagem para gerar a interface de utilizador baseada diretamente em modelos estruturais da lógica de negócio. A identificação do domínio de aplicação é um factor chave da metodologia, permitindo automatizar o processo de geração. Por sua vez a separação entre conteúdo e forma favorece o refinamento iterativo das interfaces geradas.

Abstract
The paper briefly explores a layered approach to the analysis of two interactive systems (Nuclear Control and Air Traffic Control), indicating how the analysis enables exploration of the particular features emphasised by the use cases relating to the examples. These features relate to the interactive behaviour of the systems. To facilitate the analysis, property templates are proposed as heuristics for developing appropriate requirements for the respective user interfaces.

Abstract
Inspired by the relational algebra of data processing, this paper addresses the foundations of data analytical processing from a linear algebra perspective. The paper investigates, in particular, how aggregation operations such as cross tabulations and data cubes essential to quantitative analysis of data can be expressed solely in terms of matrix multiplication, transposition and the Khatri-Rao variant of the Kronecker product. The approach offers a basis for deriving an algebraic theory of data consolidation, handling the quantitative as well as qualitative sides of data science in a natural, elegant and typed way. It also shows potential for parallel analytical processing, as the parallelization theory of such matrix operations is well acknowledged.

Abstract
Data analysis is among the main strategies of our time for enterprises to take advantage of the vast amounts of data their systems generate and store everyday. Thus the standard relational database model is challenged everyday to cope with quantitative operations over a traditionally qualitative, relational model. A novel approach to the semantics of data is based on (typed) linear algebra (LA), rather than relational algebra, bridging the gap between data dimensions and data measures in a unified way. Also, this bears the promise of increased parallelism, as most operations in LA admit a ‘divide & conquer’ implementation. This paper presents a first experiment in implementing such a typed linear algebra approach and testing its performance on a data distributed system. It presents solutions to some theoretical limitations and evaluates the overall performance.

Abstract
This paper introduces the metaphorism pattern of relational specification and addresses how specification following this pattern can be refined into recursive programs. Metaphorisms express input-output relationships which preserve relevant information while at the same time some intended optimization takes place. Text processing, sorting, representation changers, etc., are examples of metaphorisms. The kind of metaphorism refinement proposed in this paper is a strategy known as change of virtual data structure. It gives sufficient conditions for such implementations to be calculated using relation algebra and illustrates the strategy with the derivation of quicksort as example.

Abstract
In the trend towards tolerating hardware unreliability, accuracy is exchanged for cost savings. Running on less reliable machines, functionally correct code becomes risky and one needs to know how risk propagates so as to mitigate it. Risk estimation, however, seems to live outside the average programmer's technical competence and core practice. In this paper we propose that program design by source-to-source transformation be risk-aware in the sense of making probabilistic faults visible and supporting equational reasoning on the probabilistic behaviour of programs caused by faults. a la Bird-Moor algebra of programming. This paper studies, in particular, the propagation of faults across standard program transformation techniques known as tupling and fusion, enabling the fault of the whole to be expressed in terms of the faults of its parts.