Browsing by Author "Fonseca, Manuel"

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    Ensaio de Avaliação Preditiva para Utilizadores com Necessidades Especiais
    (The Eurographics Association, 2021) Artífice, Andreia; Lopes, João Brisson; Jorge, Joaquim; Fonseca, Manuel João; Coelho, António and Cláudio, Ana Paula
    This paper addresses the prediction of likely user moves in a practical case study where user interaction is pre­dicted on the basis of lambda-parameters acquired from users with special needs playing a software game. A model was built to reproduce actions performed by such users in a 3D world to overcome the difficult set-up of tests due to user reduced availability, mobility and varying/erratic behaviour. User actions data was obtained from usability tests where users played a game requiring them to move around a virtual house and perform some ac­tivities. The tests were carried out with users with disabilities such as severe physical injuries, cerebral palsy and Down syndrome. A three level simulator was developed with data extracted from part o the data collected during experiments, the remaining raw experimental data serving as reference for validation. Data analysis cal­culated the λ-parameter required by the Poisson and Exponential Distributions used by the statistical approach adopted. The tests performed showed an excellent statistical flt of the simulated data to the reference data.
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    Polygon Detection from a Set of Lines
    (The Eurographics Association, 2021) Jr., Alfredo Ferreira; Fonseca, Manuel; Jorge, Joaquim; Marcos, Adérito and Mendonça, Ana and Leitão, Miguel and Costa, António and Jorge, Joaquim
    Detecting polygons defined by a set of line segments in a plane is an important step in the analysis of vectorial drawings. This paper presents an approach that combines several algorithms to detect basic polygons from a set of arbitrary line segments. The resulting algorithm runs in polynomial time and space, with complexities of O((N + M)4) and O((N + M)2) respectively, where N is the number of line segments and M is the number of intersections between line segments. Our choice of algorithms was made to strike a good compromise between efficiency and ease of implementation. The result is a simple and efficient solution to detect polygons from lines.
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    Task Analysis and Scenario-Based Design of Calligraphic Interfaces
    (The Eurographics Association, 2021) Dias, Filipe; Fonseca, Manuel; Jorge, Joaquim; Marcos, Adérito and Mendonça, Ana and Leitão, Miguel and Costa, António and Jorge, Joaquim
    The great functionality of today's CAD systems enables the manufacturing of very complex models. Yet, great part of this power is unusable, early in the design process. As well, we have found two different approaches in two different car designers that surprisingly lead to the same long time in development. In this paper we identify the reasons for these problems, and propose a solution that bridges the different worlds of conceptual and geometric models, using the affordability of the calligraphic interface. Creating a prototype by drawing it allows impossible situations to be immediately identified and corrected, without further communication overheads, certifying that emotional drawing ideas correspond to the designer's intents.