58 documents found, page 1 of 6
Precision Agriculture in silvopastoral systems: A case study from the Montado (...
Marques, J.H.; Paniágua, L.; Carreira, Emanuel; Mendes, S.; Lloberas, D.; Serrano, JoãoThe Montado is a distinctive silvopastoral system of the Southern Iberian Peninsula, integrating pastures, trees (typically cork oak, Quercus suber, and/or holm oak, Quercus rotundifolia), and domestic livestock (ruminants or swine). Precision Agriculture (PA), predominantly explored in purely agricultural systems, offers substantial potential to optimize Montado management, thereby enhancing its economic, envi...
Quaternionic essential numerical range of complex operators
Carvalho, L.; Diogo, C.; Mendes, S.; Soares, H.We study the essential numerical range of complex operators on a quaternionic Hilbert space and its relation with the essential S-spectrum. We give a new characterization of the essential numerical range relating it to the complex essential numerical range. Moreover, we show that the quaternionic essential numerical range of a normal operator is the convex hull of the essential S-spectrum.
A note on the essential numerical range of block diagonal operators
Carvalho, L.; Diogo, C.; Mendes, S.; Soares, H.In this note, we characterize the essential numerical range of a block diagonal operator T = ?i Ti in terms of the numerical ranges {W(Ti)}i of its components. Specifically, the essential numerical range of T is the convex hull of the limit superior of {W(Ti)}i. This characterization can be simplified further. In fact, we prove the existence of a decomposition of T for which the convex hull is not required.
On the relation between S-spectrum and right spectrum
Carvalho, L.; Diogo, C.; Mendes, S.; Soares, H.We use the R-linearity of I?-T to define ?(T), the right spectrum of a right H-linear operator T in a right quaternionic Banach space. We show that ?(T) coincides with the S-spectrum ?S(T).
On the convexity of the quaternionic essential numerical range
Carvalho, L.; Diogo, C.; Mendes, S.; Soares, H.The numerical range in the quaternionic setting is, in general, a non-convex subset of the quaternions. The essential numerical range is a refinement of the numerical range that only keeps the elements that have, in a certain sense, infinite multiplicity. We prove that the essential numerical range of a bounded linear operator on a quaternionic Hilbert space is convex. A quaternionic analogue of Lancaster theor...
Negotiating policy ideas: Participatory action research projects across five Eu...
Bröer, C.; Veltkamp, G.; Ayuandini, S.; Baillergeau, E.; Moerman, G.; de Sauvage, R.; Banik, A.; Luszczynska, A.; Rito, Ana; Mendes, S.; Klepp, K.-I.Introduction - Between 2019 and 2021, 199 adolescents collaborated with adults in 15 participatory action research projects, called Youth Alliances, to contribute to system-directed obesity prevention in five EU countries. We investigated if and how these Youth Alliances included diverse youth, enhanced engagement, generated policy proposals and changed problem perception. Theory We assessed the Youth Alliances...
Effect of rearing temperature in the growth of hatchery reared juveniles of the...
Madruga, A.S.; Félix, P.M.; Sousa, J.; Silva, F. Azevedo e; Brito, A.C.; Mendes, S.; Pombo, A.Since the early 1980's there has been an increase in sea cucumber harvest and trade, mainly due to Asiatic market pressure. In the Indo-Pacific regions, the collapse of various stocks of these echinoderms has already occurred due to overfishing. In Europe, sea cucumber exportation depends exclusively on wild stock harvesting, which has demonstrated to be an unsustainable method to supply the markets, as these s...
Numerical representation of topological real algebras
Mendes, S.; Bettencourt, G. H.We show that the isomorphism provided by the Gelfand-Mazur theorem for a commutative pre-ordered real Banach algebra A with unit defines a numerical representation which is compatible with the order structure.
The intersectional effects of motivational and affective factors on managers’ p...
Junça Silva, A.; Mendes, S.Purpose: Drawing from the effort-recovery model, the authors analysed the role of daily sleep quality as a driver for self-regulatory resources and consequently of task and contextual performance. Specifically, the authors hypothesised that self-regulatory resources would be a potential mechanism for enhancing workers’ performance after a good night's sleep. Moreover, relying on the COR theory, the authors prop...
Metric functionals for the Hästö metric
Bettencourt, G.; Mendes, S.In 2002, new classes of weighted metrics on R^n were introduced by Peter Hästö. In this article we compute the metric functionals for such classes of metrics.