372 research outputs found
Regionalization and susceptibility assessment to daily precipitation extremes in mainland Portugal
The present study aims to identify regions of extreme precipitation in mainland Portugal and to create a
single index of extreme precipitation susceptibility (EPSI). For this purpose, twelve extreme precipitation
indices were selected from the Expert Team on Climate Change Detection and Indices between 1950 and
2003. By considering only six extreme precipitation indices: R 1day, R 5day, SDII, R20, CWD and
R95PTOT for the 10-year return period, between 1950 and 2003, the EPSI was developed to both annual
data and meteorological season. The regionalization of extreme precipitation in Portugal were determined using a principal component analysis in T-mode. The results, show three spatial regions obtained
from PCA. The three regions were analyzed separate. In the annual EPSI, the highest susceptibility areas
are the mountainous regions in northern (e.g. Geres, Peneda, Alv ^ ~
ao, Marao and Montesinho) and central ~
Portugal (e.g. Serra da Estrela), as well as in the Algarve (southern Portugal). Conversely, the lower
susceptibility classes are in municipalities of the northeast, Alentejo and along the central-western coast.
The results of EPSI show similar results in autumn and winter. In spring, however, the high susceptibility
class increases in the Lisbon region and in the Sado Basin. In summer, there is an increase in susceptibility in the northeast, while susceptibility is low over much of Alentejo and Algarve, where precipitation
is neglectful. This work presents a first attempt to implement this type of index for mainland Portugal.
The first results are very promising, showing a consistent representation of the overall spatial distribution of extreme precipitation susceptibility. The combination of this information by municipalities can
be of foremost relevance to civil protection and risk management.info:eu-repo/semantics/publishedVersio
On the multi-mode, multi-skill resource constrained project scheduling problem (MRCPSP-MS)
In this paper we describe an extension of the Resource-Constrained Project Scheduling Problem (RCPSP). A literature review is presented to place our research in its proper context. The problem presented here belongs to the class of the optimization scheduling problems with multi-level (or multi-mode) activities. This means that the activities can be scheduled at different modes, each mode using a different resource level, implying different costs and durations. Each activity must be allocated exactly one unit of each required resource and the resource unit may be used at any of its specified levels. The processing time of an activity is given by the maximum of the durations that would result from a specific allocation of resources. The objective is to find the optimal solution that minimizes the overall project cost, while respecting a delivery date. A penalty is included for tardiness beyond the specified delivery date. We present a formal description of the problem and a mathematical model for it. We also introduce the implementation algorithm for the problem. The implementation was designed using the JAVA language, and the algorithm proposed is based on a branch and bound procedure, using breadth-first search (BFS) project network traversing, among some heuristic rules to filter large subsets of fruitless candidates relative to resource levels combinations.Fundação para a Ciência e a Tecnologia (FCT
On the multi-mode, multi-skill resource constrained project scheduling problem : computational results
This paper is concerned with an extension of the Resource-Constrained Project Scheduling Problem (RCPSP) which belongs to the class of the optimization scheduling problems with multi-level (or multi-mode) activities. We developed a practical tool, useful to represent multi-mode projects, and to find a solution for the problem on hand – select the best mode for each resource in each activity in order to minimize the total cost, considering the resource cost, a penalty for tardiness and a bonus for early completion. We implemented an adaptation of a filtered beam search (FBS) algorithm to this problem, using the C# programming language. A “filtered beam” search is a heuristic Branch and Bound (BaB) procedure that uses breadth first search but only the top “best” nodes are kept. We give some of the most important solution details and we report on further computational results, by testing the application for different problem sizes
Multi-mode resource constrained project scheduling problem including multi-skill labor (MRCPSP-MS): model and a solution method
The problem that we address in this chapter is an extension of the Resource-Constrained Project Scheduling Problem (RCPSP). It belongs to the class of project scheduling problems with multi-level (or multi-mode) activities, that permit an activity to be processed by resources operating at appropriate modes, where each mode belongs to a different resource level and incurs different cost and duration. Each activity must be allocated exactly one unit of each required resource, and the resource unit may be used at any of its specified levels. The processing time of an activity is given by the maximum of the durations that would result from different resources allocated to that activity. The objective is to find an optimal solution that minimizes the overall project cost, given a delivery date. A penalty is incurred for tardiness beyond the specified delivery date, or a bonus is accrued for early completion. We present a mathematical programming formulation as an accurate problem definition. A Filtered Beam Search (FBS)-based method is used to solve the problem. It was implemented using the C# language. Results of our experimentations on the use of this method are also presented.(undefined
On the multi-mode, multi-skill resource constrained project scheduling problem : a software application
We consider an extension of the Resource-Constrained Project Scheduling Problem (RCPSP) to multi-level (or multi-mode) activities. Each activity must be allocated exactly one unit of each required resource and the resource unit may be used at any of its specified levels. The processing time of an activity is given by the maximum of the durations that would result from a specific allocation of resources. The objective is to find the optimal solution that minimizes the overall project cost which includes a penalty for tardiness beyond the specified delivery date as well as a bonus for early delivery. We give some of the most important solution details and we report on the preliminary results obtained. The implementation was designed using the C# language
Historic and recent occurrences of pinnipeds in the Archipelago of the Azores
UID/HIS/04666/2013publishersversionpublishe
An exponential equation of state of dark energy in the light of 2018 CMB Planck data
The dynamics of the Universe is analyzed using an exponential function for
the dark energy equation of state, known as Gong-Zhang parameterization. The
phase space of the free parameters presented in the model is constrained using
Cosmic Microwave Background radiation, Cosmic Chronometers, modulus distance
from Hydrogen II Galaxies, Type Ia Supernovae and measurements from Baryon
Acoustic Oscillations, together with a stronger bound from a Joint analysis.
The cosmological model is confronted with CDM, observing there is a
strong evidence for CDM in the Joint analysis although the exponential
model is preferred when the data are separated. Based on the Joint analysis, a
value of is found for the characteristic
parameter presented in the equation of state. Additionally, the cosmographic
parameters at current times are reported, having , , and a transition
deceleration-acceleration redshift .
Furthermore, the age of the Universe is estimated as Gyrs. Finally, we open a discussion if this model
could alleviate the and tensions.Comment: Accepted in Physics of Dark Univers
Historic and recent occurrences of pinnipeds in the Archipelago of the Azores
Author Posting. © The Author(s), 2009. This is the author's version of the work. It is posted here by permission of Walter de Gruyter for personal use, not for redistribution. The definitive version was published in Mammalia 73 (2009): 60-62, doi:10.1515/MAMM.2009.008.The Archipelago of the Azores (Portugal) is located between 37º and 41ºN and 25º and
31ºW and crosses the Mid-Atlantic Ridge. It is the most isolated archipelago in the
Atlantic, situated 1600 km west of mainland Portugal and 3500 km from the eastern
coast of the United States of America. At present, the only population of seals occurring
in the Portuguese territory is found on Desertas Islands, Archipelago of Madeira, where
a colony of 24 Mediterranean monk seals, Monachus monachus (Hermann, 1779), still
persists (Pires and Neves 2001). Nonetheless, historical accounts reported by Frutuoso
(1983) dating from the early to late 1500's mention sightings of "sea wolves" (the old
Portuguese folk term for the Mediterranean monk seal) at several sites along the
Azorean Island of Santa Maria. Little is known about the occurrence of monk seals in
this area over the past five centuries, but the species certainly did not escape deliberate
killing by the first settlers. While the early monk seal reports by Frutuoso (1983) are the
only ones referring to the presence of colonies of seals in the Azores, more recently
several sightings and strandings of vagrant seals of other species have been noted. Here
we summarize historical knowledge describing colonies of Mediterranean monk seals in
the Azores, review published records of pinnipeds from the 20th century and report new
sightings and strandings of seals in the Azores.M.A.S. was supported by an FCT postdoctoral grant
(SFRH/BPD/29841/2006), co-funded by POCI2010 and FSE. C.B. was supported by an
FCT doctoral grant (SFRH/BD/21836/2005). IMAR- DOP/UAç is the R&D Unit #531
and part of the Associated Laboratory #9 (ISR) funded through the pluri-annual and
programmatic funding schemes of FCT-MCTES and DRCT-Azores
Aplicação exploratória de análise multicritério para representação municipal da susceptibilidade a cheias rápidas em Portugal continental
[...] Este estudo descreve uma metodologia exploratória de avaliação de susceptibilidade a cheias rápidas
para Portugal Continental, adotando uma abordagem multicritério, a partir de um conjunto de 9 fatores
condicionantes, definidos ao município: escoamento acumulado, hierarquia fluvial de Strahler,
rugosidade, declive, depósitos aluvionares, grau de impermeabilização, litologia de elevada
permeabilidade, Landform Classification e escoamento anual. A atribuição do peso de cada fator
baseou-se em Análise Hierárquica de Processos (AHP) [...]info:eu-repo/semantics/publishedVersio
Baleen whale acoustic presence and behaviour at a Mid-Atlantic migratory habitat, the Azores Archipelago
This work was supported by Fundação para a Ciência e Tecnologia (FCT), Azores 2020 Operational Programme and Fundo Regional da Ciência e Tecnologia (FRCT) through research projects TRACE (PTDC/MAR/74071/2006), MAPCET (M2.1.2/F/012/2011) and AWARENESS (PTDC/BIA-BMA/30514/201), co-funded by FEDER, COMPETE, QREN, POPH, ERDF, ESF, the Lisbon Regional Operational Programme, and the Portuguese Ministry for Science and Education. Funding for publication fees was provided by Project AWARENESS (PTDC/BIA-BMA/30514/201). Okeanos R&D Centre is supported by FCT, through the strategic fund (UIDB/05634/2020). MR was supported by a DRCT doctoral grant (M3.1.a/F/028/2015) and MAS by an FCT-Investigator contract (IF/00943/2013). TAM thanks partial support by CEAUL (funded by FCT - Fundação para a Ciência e a Tecnologia, Portugal, through the project UID/MAT/00006/2013).The identification of important areas during the annual life cycle of migratory animals, such as baleen whales, is vital for their conservation. In boreal springtime, fin and blue whales feed in the Azores on their way to northern latitudes while sei whales migrate through the archipelago with only occasional feeding. Little is known about their autumn or winter presence or their acoustic behaviour in temperate migratory habitats. This study used a 5-year acoustic data set collected by autonomous recorders in the Azores that were processed and analysed using an automated call detection and classification system. Fin and blue whales were acoustically present in the archipelago from autumn to spring with marked seasonal differences in the use of different call types. Diel patterns of calling activity were only found for fin whales with more calls during the day than night. Sei whales showed a bimodal distribution of acoustic presence in spring and autumn, corresponding to their expected migration patterns. Diel differences in sei whale calling varied with season and location. This work highlights the importance of the Azores as a migratory and wintering habitat for three species of baleen whales and provides novel information on their acoustic behaviour in a mid-Atlantic region.Publisher PDFPeer reviewe
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