http://hdl.handle.net/10174/14452 Mon, 06 Apr 2026 20:17:24 GMT 2026-04-06T20:17:24Z http://hdl.handle.net/10174/26986 Title: Pastor.i _ Uma aplicação de smartphone para facilitar a gestão do pastoreio Authors: Sales-Baptista, Elvira; Ferraz-de-Oliveira, Maria Isabel; Cancela d'Abreu, Manuel; Salgueiro, Pedro; Rato, Luís Miguel Abstract: Grazing in extensive beef farming systems is often manage in an empirical way based on past experience and on the visual appreciation of animal behavior and forage potential. Records of entrances and exits of the animals in the paddocks in a regular basis are rare. However, knowing the occupation period and the animal density, when coupled with biomass defines the grazing pressure and carry capacity. This knowledge is essential for planning and making informed decisions, that influence the profitability of the farm. Moreover, adequate grazing pressure is crucial for the sustainability of many SSPs where system maintenance is dependent on the balance between grazing pressure and regeneration or maintenance of trees and shrubs. Pastor.i is a smartphone application (APP) designed to allow pasture data logging to be very simple. The application is synchronized with the website and allows the producer to have in his pocket all the farm, being possible to identify the paddock, calculate the area, record the movements of the animals and consult the occupation history of the paddock. The application calculates the actual stocking rate, that can be associated with the location of the animals, obtained if the animals are using collars with GPS, which allows to know the areas of the paddock that are most grazed, visualized through heat maps. The information enables localized actions, such as fertilizing or sowing, to improve areas that are not grazed. The application also allows you to save photos of the sward. This temporal photographic record provides information on the condition of trees, the botanical composition and on the tendency of grazing to improve or to worsen coverage. The APP is available for download, is compatible with Android and is being tested with focus groups. Wed, 31 Oct 2018 00:00:00 GMT http://hdl.handle.net/10174/26986 2018-10-31T00:00:00Z http://hdl.handle.net/10174/25724 Title: Towards a formal specification of local search neighborhoods from a constraint satisfaction problem structure Authors: Mateusz, Ślażyński; Salvador, Abreu; Grzegorz, Nalepa Editors: López-Ibáñez, Manuel Abstract: Neighborhood operators play a crucial role in defining effective Local Search solvers, allowing one to limit the explored search space and prune the fitness landscape. Still, there is no accepted formal representation of such operators: they are usually modeled as algorithms in procedural language, lacking in compositionality and readability. In this paper we outline a new formalization capable of representing several neighborhood operators eschewing their coding in a full Turing complete language. The expressiveness of our proposal stems from a rich problem representation, as used in Constraint Programming models. We compare our system to competing approaches and show a clear increment in expressiveness. Sun, 30 Jun 2019 23:00:00 GMT http://hdl.handle.net/10174/25724 2019-06-30T23:00:00Z http://hdl.handle.net/10174/24781 Title: Improving Constraint Solving on Parallel Hybrid Systems Authors: Roque, Pedro; Pedro, Vasco; Diaz, Daniel; Abreu, Salvador Abstract: Recently, we developed the Parallel Heterogeneous Architecture Constraint Toolkit (PHACT), which is a multi-threaded constraint solver capable of using all the available devices which are compatible with OpenCL, in order to speed up the constraint satisfaction process. In this article, we introduce an evolution of PHACT which includes the ability to execute FlatZinc and MiniZinc models, as well as architectural improvements which boost the performance in solving CSPs, especially when using GPUs. Thu, 01 Nov 2018 00:00:00 GMT http://hdl.handle.net/10174/24781 2018-11-01T00:00:00Z http://hdl.handle.net/10174/24751 Title: Declarative Programming and Knowledge Management Authors: Seipel, Dietmar; Hanus, Michael; Abreu, Salvador Editors: Seipel, Dietmar; Hanus, Michael; Abreu, Salvador Abstract: Conference on Declarative Programming, DECLARE 2017, Unifying INAP, WFLP, and WLP, Würzburg, Germany, September 19–22, 2017, Revised Selected Papers Mon, 01 Jan 2018 00:00:00 GMT http://hdl.handle.net/10174/24751 2018-01-01T00:00:00Z