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Publications

2009

TetraScript: Development of an Integrated System Capable of Optimizing Light in a Circumscribed Space

Authors
Henriques, GC; Duarte, JP; Brito, AC;

Publication
ECAADE 2009: COMPUTATION: THE NEW REALM OF ARCHITECTURAL DESIGN

Abstract
The purpose of this research is to develop a process capable of optimizing the capture of light in a circumscribed space, using a responsive system of skylights. Research is focused on the design of irregular dome-like pavilion spaces circumscribed by curved surfaces, but the envisioned process might be applied to other functional, formal, and spatial typologies. The design of the pavilion starts with the generation of a surface, later tessellated into a matrix of skylights depending on the geographic location and sun orientation. In the constructed pavilion, the skylights react to the variation of daylight intensity during the day to satisfy specified internal lighting needs. Simultaneously, the integration of conception and fabrication using digital tools (CAD-CAM) facilitates the construction of a non-standard, parametric geometry, thereby diminishing the costs of production and allowing for personalization, while assuring global sustainability.

2009

Special track on data streams

Authors
Gama, J; Carvalho, A; Rodrigues, PP; Aguilar, J;

Publication
Proceedings of the ACM Symposium on Applied Computing

Abstract

2009

Advanced Data Mining and Applications: 5th International Conference, ADMA 2009 Beijing, China, August 17-19, 2009 Proceedings - Preface

Authors
Qiang, Y; Ronghuai, H; Jian, P; Gama, J; Xiaofeng, M;

Publication
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)

Abstract

2009

UML Model Refactoring as Refinement: A Coalgebraic Perspective

Authors
Barbosa, LS; Meng, S;

Publication
PROCEEDINGS OF THE 10TH INTERNATIONAL SYMPOSIUM ON SYMBOLIC AND NUMERIC ALGORITHMS FOR SCIENTIFIC COMPUTING

Abstract
Although increasingly popular, Model Driven Architecture (MDA) still lacks suitable formal foundations on top of which rigorous methodologies for the description, analysis and transformation of models could be built. This paper aims to contribute in this direction: building on previous work by the authors on coalgebraic refinement for software components and architectures, it discusses refactoring of models within a coalgebraic semantic framework. Architectures are defined through aggregation based on a coalgebraic semantics for (subsets of) UML. On the other hand, such aggregations, no matter how large and complex they are, can always be dealt with as coalgebras themselves. This paves the way to a discipline of models, transformations which, being invariant under either behavioural equivalence or refinement, are able to formally capture a large number of refactoring patterns. The main ideas underlying this research are presented through a detailed example in the context of refactoring of UML class diagrams.

2009

RNase-Based Gametophytic Self-Incompatibility Evolution: Questioning the Hypothesis of Multiple Independent Recruitments of the S-Pollen Gene

Authors
Vieira, J; Fonseca, NA; Vieira, CP;

Publication
JOURNAL OF MOLECULAR EVOLUTION

Abstract
Multiple independent recruitments of the S-pollen component (always an F-box gene) during RNase-based gametophytic self-incompatibility evolution have recently been suggested. Therefore, different mechanisms could be used to achieve the rejection of incompatible pollen in different plant families. This hypothesis is, however, mainly based on the interpretation of phylogenetic analyses, using a small number of divergent nucleotide sequences. In this work we show, based on a large collection of F-box S-like sequences, that the inferred relationship of F-box S-pollen and F-box S-like sequences is dependent on the sequence alignment software and phylogenetic method used. Thus, at present, it is not possible to address the phylogenetic relationship of F-box S-pollen and S-like sequences from different plant families. In Petunia and Malus/ Pyrus the putative S-pollen gene(s) show(s) variability patterns different than expected for an S-pollen gene, raising the question of false identification. Here we show that in Petunia, the unexpected features of the putative S-pollen gene are not incompatible with this gene's being the S-pollen gene. On the other hand, it is very unlikely that the Pyrus SFBB-gamma gene is involved in specificity determination.

2009

A market based active/reactive dispatch including transformer taps and reactor and capacitor banks using Simulated Annealing

Authors
Gomes, MH; Saraiva, JT;

Publication
ELECTRIC POWER SYSTEMS RESEARCH

Abstract
This paper describes an optimization model to be used by System Operators in order to validate the economic schedules obtained by Market Operators together with the injections from Bilateral Contracts. These studies will be performed off-line in the day before operation and the developed model is based on adjustment bids submitted by generators and loads and it is used by System Operators if that is necessary to enforce technical or security constraints. This model corresponds to an enhancement of an approach described in a previous paper and it now includes discrete components as transformer taps and reactor and capacitor banks. The resulting mixed integer formulation is solved using Simulated Annealing, a well known metaheuristic specially suited for combinatorial problems. Once the Simulated Annealing converges and the values of the discrete variables are fixed, the resulting non-linear continuous problem is solved using Sequential Linear Programming to get the final solution. The developed model corresponds to an AC version, it includes constraints related with the capability diagram of synchronous generators and variables allowing the computation of the active power required to balance active losses. Finally, the paper includes a Case Study based on the IEEE 118 bus system to illustrate the results that it is possible to obtain and their interest.

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