2007
Authors
Rodrigues, NF; Barbosa, LS;
Publication
JOURNAL OF UNIVERSAL COMPUTER SCIENCE
Abstract
Program slicing is a well known family of techniques intended to identify and isolate code fragments which depend on, or are depended upon, specific program entities. This is particularly useful in the areas of reverse engineering, program understanding, testing and software maintenance. Most slicing methods, and corresponding tools, target either the imperative or the object oriented paradigms, where program slices are computed with respect to a variable or a program statement. Taking a complementary point of view, this paper focuses on the slicing of higher-order functional programs under a lazy evaluation strategy. A prototype of a Haskell slicer, built as proof-of-concept for these ideas, is also introduced.
2006
Authors
Coelho, A; Bessa, M; de Sousa, AA; Ferreira, FN;
Publication
Ibero-American Symposium in Computer Graphics, SIACG 2006, Santiago de Compostela, Spain, July 5-7, 2006
Abstract
This paper presents Geospatial L-systems, a new extension of L-systems that incorporates geospatial awareness, and shows an application of this new tool in the expeditious modelling of urban environments, integrated with a modelling system with interoperable access to data sources. L-systems have been used in Computer Graphics for the modelling of plants, and in a few experiments to model urban environments. However, the lack of geospatial awareness is a limitation and in spite of some developments like open l-systems introduced the ability to communicate with the environment, there was a need for more flexibility. A new modelling system, named XL3D, generates virtual urban environments automatically from a XL3D document with a modelling specification. This modelling system accesses data sources in a interoperable way and the modelling processes are based on L-systems. The integration of geospatial L-systems with the XL3D modelling system has increased its potential for automation and improved the potential to generate virtual urban environments with a higher level of detail and visual fidelity, with a lower level of complexity of the modelling processes. These facts are shown in a case study where a virtual urban environment taken from an area in the Porto downtown is generated by this solution. © The Eurographics Association 2006.
2006
Authors
Oliveira, E; Sousa, AAd;
Publication
Abstract
2006
Authors
Carvalho, A; Ribeiro, C; Sousa, AA;
Publication
Research and Practical Issues of Enterprise Information Systems
Abstract
The importance of the spatial component of data items has been long recognized and gave rise to a successful line of research and development in Geographic Information Systems (GIS). In many application domains it is also essential to deal with the evolution of data along time and to integrate spatial, temporal and other aspects of the information domain in an expressive and operationally effective manner. Until recently, temporal solutions provided by spatial database systems were semi-temporal approaches lacking full temporal support. As a consequence, most spatial database systems manage snapshots of the present state of facts without fully exploiting historical temporal aspects. This paper provides preliminary results on a spatiotemporal database implementation. The proposed system builds on existing database technologies, TimeDB and Oracle Spatial, for temporal and spatial support, respectively. The justification for the choice of these technologies is given, based on the state of the art in spatial and temporal database research. The integration of the spatial and temporal components is achieved with the extension of the TimeDB implementation layer. A set of goals has been established in order to cover both the integration of the spatial support and the enforcement of the temporal requirements in the extended system. Issues and solutions are presented and illustrative examples show the use of the implemented functionalities.
2006
Authors
Moreira, PM; Reis, LP; De Sousa, AA;
Publication
International Journal of Simulation Modelling
Abstract
In this paper we address the problem of automatically computing a set of views over a simulated three dimensional environment. The viewing system aims at, for each moment, supplying the user with the most pertinent information in order to allow a good understanding of the evolving environment. Our approach relies on an innovative optimization architecture that enables intelligent optimization techniques based on simulated annealing and genetic algorithms. Reported experiments were performed in urban rescue scenarios from the RoboCup Rescue Domain. We outline the possible extension of the proposed architecture to other visualization problems and argue on how several problems within the fields of Visualization and Rendering can benefit from it.
2006
Authors
Aguiar, A; David, G;
Publication
EuroPLoP' 2006, Eleventh European Conference on Pattern Languages of Programs, Irsee, Germany, July 5-9, 2006
Abstract
Good design and implementation are necessary but not sufficient pre-requisites for the successful reuse of object-oriented frameworks. Although not always recognized, good documentation is crucial for effective framework reuse and comes with many issues. Defining and writing good quality documentation for a framework is often hard, costly, and tiresome, especially when not aware of its key problems and the best ways to address them. This document presents patterns from a set of related patterns that describe proven solutions to recurrent problems of documenting object-oriented frameworks. The pattern language they all form together aims at helping non-experts on cost-effectively documenting object-oriented frameworks. The patterns here presented address the problems of explaining how to use a framework and illustrating what it can be good for, respectively the patterns "COOKBOOK & RECIPES" and "GRADED EXAMPLES".
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