Nuno Correia

Comparison of mode decomposition methods tested on simulated surfaces

Multiple modal decomposition of surfaces methods are increasingly used to analyse the typical geometric defects of manufactured surfaces. According to the context, this decomposition can either be done on a base which is known a priori (e.g. Discrete Cosine Transform, natural vibration modes etc.) or on a base that is identified from a set of measured surfaces (i.e. manufacturing dependent “technological modes” using the Principal Components Analysis or Independent components analysis). In this paper, a set of simulated surfaces are generated by linear combination of a given typical defect set in order to compare the efficiency the two different techniques. The compared techniques are, 1) methods founded on an a priori base and, 2) multivariate analysis methods (The key modes are identified for each method and compared to the technological modes used to generate the trial surfaces. From this study it may be concluded that while the first method does not allow the identification of the technological modes, the second does provide possible insight into the production technologies.

Group Support Systems Features and Their Contribution to Technology Strategy Decision-Making: A Review and Analysis

Collective decision-making processes require careful design considerations in organizations. On one hand, the inclusion of a greater number of actors contribute to a wider knowledge base, on the other, it can become a diffuse process and be distorted from the principles initially established. This paper observes a specific collective decision making process in organizations—technology strategy formulation—and, through a critical review of the literature, analyzes how the advances in features of group support systems support improvements in different stages of this process. This paper also discusses the implications of GSS appropriation in group dynamics.