DSpace Collection:
https://hdl.handle.net/10216/25696
2019-07-23T01:12:56ZARFIMA-GARCH modeling of HRV: Clinical application in acute brain injury
https://hdl.handle.net/10216/106923
Title: ARFIMA-GARCH modeling of HRV: Clinical application in acute brain injury
Abstract: In the last decade, several HRV based novel methodologies for describing and assessing heart rate dynamics have been proposed in the literature with the aim of risk assessment. Such methodologies attempt to describe the non-linear and complex characteristics of HRV, and hereby the focus is in two of these characteristics, namely long memory and heteroscedasticity with variance clustering. The ARFIMA-GARCH modeling considered here allows the quantification of long range correlations and time-varying volatility. ARFIMA-GARCH HRV analysis is integrated with multimodal brain monitoring in several acute cerebral phenomena such as intracranial hypertension, decompressive craniectomy and brain death. The results indicate that ARFIMA-GARCH modeling appears to reflect changes in Heart Rate Variability (HRV) dynamics related both with the Acute Brain Injury (ABI) and the medical treatments effects. (c) 2017, Springer International Publishing AG.2017-01-01T00:00:00ZPH2 - A Public A Public Database for the Analysis of Dermoscopic Images
https://hdl.handle.net/10216/110404
Title: PH2 - A Public A Public Database for the Analysis of Dermoscopic Images2016-01-01T00:00:00ZParallel Algorithms for Multirelational Data Mining: Application to Life Science Problems
https://hdl.handle.net/10216/86854
Title: Parallel Algorithms for Multirelational Data Mining: Application to Life Science Problems2016-11-09T00:00:00ZInduction as a search procedure
https://hdl.handle.net/10216/67123
Title: Induction as a search procedure
Abstract: This chapter introduces inductive logic programming (ILP) from the perspective of search algorithms in computer science. It first briefly considers the version spaces approach to induction, and then focuses on inductive logic programming: from its formal definition and main techniques and strategies, to priors used to restrict the search space and optimized sequential, parallel, and stochastic algorithms. The authors hope that this presentation of the theory and applications of inductive logic programming will help the reader understand the theoretical underpinnings of ILP, and also provide a helpful overview of the State-of-the-Art in the domain. (c) 2008, IGI Global.2008-01-01T00:00:00ZAlgal spent biomass - a pool of applications
https://hdl.handle.net/10216/119134
Title: Algal spent biomass - a pool of applications2019-01-01T00:00:00ZMicroalgal fatty acids - From harvesting until extraction (Cap. 16)
https://hdl.handle.net/10216/116663
Title: Microalgal fatty acids - From harvesting until extraction (Cap. 16)
Abstract: Microalgal biomass can be "energy rich," but the growth of algae in dilute suspension around 0.02%-0.05% dry solids is a considerable challenge in achieving a viable energy balance in a microalgal biofuel process. Many researchers consider that efficient harvesting is the major challenge of microalgal biofuel commercialization but a single method or combination of harvesting methods suited to all microalgae does not exist. Additionally, lipid extraction continues to be a significant trial even though a multitude of extraction methods, especially in what concerns the presence of residual water in the microalgal biomass; its effects on lipid extraction or the need of cell disruption are still not well understood.In this chapter, these critical points on biofuel production-biomass harvesting and dewatering, biomass pretreatment, and fatty acid extraction methods-will be discussed.2017-01-01T00:00:00ZQuantity Competition in a Differentiated Duopoly
https://hdl.handle.net/10216/91369
Title: Quantity Competition in a Differentiated Duopoly
Abstract: In this paper, we consider a Stackelberg duopoly competition with differentiated goods, linear and symmetric demand and with unknown costs. In our model, the two firms play a non-cooperative game with two stages: in a first stage, firm F 1 chooses the quantity, q 1, that is going to produce; in the second stage, firm F 2 observes the quantity q 1 produced by firm F 1 and chooses its own quantity q 2. Firms choose their output levels in order to maximise their profits. We suppose that each firm has two different technologies, and uses one of them following a certain probability distribution. The use of either one or the other technology affects the unitary production cost. We show that there is exactly one perfect Bayesian equilibrium for this game. We analyse the variations of the expected profits with the parameters of the model, namely with the parameters of the probability distributions, and with the parameters of the demand and differentiation.
Description: In this paper, we consider a Stackelberg duopoly competition with differentiated goods, linear and symmetric demand and with unknown costs. In our model, the two firms play a non-cooperative game with two stages: in a first stage, firm F 1 chooses the quantity, q 1, that is going to produce; in the second stage, firm F 2 observes the quantity q 1 produced by firm F 1 and chooses its own quantity q 2. Firms choose their output levels in order to maximise their profits. We suppose that each firm has two different technologies, and uses one of them following a certain probability distribution. The use of either one or the other technology affects the unitary production cost. We show that there is exactly one perfect Bayesian equilibrium for this game. We analyse the variations of the expected profits with the parameters of the model, namely with the parameters of the probability distributions, and with the parameters of the demand and differentiation.2009-01-01T00:00:00ZGeocronologia e petrogénese do plutonismo tardi-varisco (NW de Portugal): síntese e inferências sobre os processos de acreção e reciclagem crustal na Zona Centro-Ibérica
https://hdl.handle.net/10216/56654
Title: Geocronologia e petrogénese do plutonismo tardi-varisco (NW de Portugal): síntese e inferências sobre os processos de acreção e reciclagem crustal na Zona Centro-Ibérica
Description: No NW de Portugal ocorre um importante volume de granitóides, que correspondem a sucessivos pulsos magmáticos principalmente instalados na etapa pós-colisional da orogenia varisca (290-321 Ma). Trata-se de plutonismo com assinaturas químicas e isotópicas diversas e forte variabilidade composicional. No presente trabalho, apresenta-se uma síntese dos dados geocronológicos e petrogenéticos disponíveis e discute-se sobre o seu significado na evolução geodinâmica da cadeia varisca, nomeadamente no referente aos processos de acreção e reciclagem crustal na Zona Centro Ibérica2010-01-01T00:00:00ZBayesian price leadership
https://hdl.handle.net/10216/95216
Title: Bayesian price leadership
Abstract: In this paper, we consider a linear price setting duopoly competition with differentiated goods and with unknown costs. The firms' aims are to choose the prices of their products according to the well-known concept of perfect Bayesian Nash equilibrium. There is a firm (F 1) that chooses first the price p 1 of its good; the other firm (F 2) observes p 1 and then chooses the price p 2 of its good. We suppose that each firm has two different technologies, and uses one of them following a probability distribution. The utilization of one or the other technology affects the unitary production cost. We show that there is exactly one perfect Bayesian Nash equilibrium for this game. We analyze the advantages, for firms and for consumers, of using the technology with highest production cost versus the one with cheapest production cost.
Description: In this paper, we consider a linear price setting duopoly competition with differentiated goods and with unknown costs. The firms' aims are to choose the prices of their products according to the well-known concept of perfect Bayesian Nash equilibrium. There is a firm (F 1) that chooses first the price p 1 of its good; the other firm (F 2) observes p 1 and then chooses the price p 2 of its good. We suppose that each firm has two different technologies, and uses one of them following a probability distribution. The utilization of one or the other technology affects the unitary production cost. We show that there is exactly one perfect Bayesian Nash equilibrium for this game. We analyze the advantages, for firms and for consumers, of using the technology with highest production cost versus the one with cheapest production cost.2007-01-01T00:00:00ZTilings and Bussola for Making Decisions
https://hdl.handle.net/10216/94695
Title: Tilings and Bussola for Making Decisions
Abstract: We introduce the yes-no decision model, where individuals can make the decision yes or no. We characterize the coherent and uncoherent strategies that are Nash equilibria. Each decision tiling indicates the way coherent and uncoherent Nash equilibria co-exist and change with the relative decision preferences of the individuals for the yes, or no, decision. There are 289 combinatorial classes of decision tilings, described by the decision bussola, what shows the high complexity of making decision.
Description: We introduce the yes-no decision model, where individuals can make the decision yes or no. We characterize the coherent and uncoherent strategies that are Nash equilibria. Each decision tiling indicates the way coherent and uncoherent Nash equilibria co-exist and change with the relative decision preferences of the individuals for the yes, or no, decision. There are 289 combinatorial classes of decision tilings, described by the decision bussola, what shows the high complexity of making decision.2011-01-01T00:00:00ZChapter 14: Internal Solitary Waves System in the Mozambique Channel
https://hdl.handle.net/10216/86766
Title: Chapter 14: Internal Solitary Waves System in the Mozambique Channel2014-01-01T00:00:00ZUniversality in PSI20 fluctuations
https://hdl.handle.net/10216/94844
Title: Universality in PSI20 fluctuations
Abstract: We consider the α re-scaled PSI20 daily index positive returns r(t)α and negative returns ( − r(t))α called, after normalization, the α positive and negative fluctuations, respectively. We use the Kolmogorov-Smirnov statistical test as a method to find the values of α that optimize the data collapse of the histogram of the α fluctuations with the truncated Bramwell-Holdsworth-Pinton (BHP) probability density function (pdf) f { BHP} and the truncated generalized log-normal pdf f LN that best approximates the truncated BHP pdf. The optimal parameters we found are α { BHP}_+ = 0. 48, α { BHP}_− = 0. 46, α LN + = 0. 50 and α LN − = 0. 49. Using the optimal α′s we compute analytic approximations of the probability distributions of the normalized positive and negative PSI20 index daily returns r(t). Since the BHP probability density function appears in several other dissimilar phenomena, our result reveals a universal feature of the stock exchange markets.
Description: We consider the α re-scaled PSI20 daily index positive returns r(t)α and negative returns ( − r(t))α called, after normalization, the α positive and negative fluctuations, respectively. We use the Kolmogorov-Smirnov statistical test as a method to find the values of α that optimize the data collapse of the histogram of the α fluctuations with the truncated Bramwell-Holdsworth-Pinton (BHP) probability density function (pdf) f { BHP} and the truncated generalized log-normal pdf f LN that best approximates the truncated BHP pdf. The optimal parameters we found are α { BHP}_+ = 0. 48, α { BHP}_− = 0. 46, α LN + = 0. 50 and α LN − = 0. 49. Using the optimal α′s we compute analytic approximations of the probability distributions of the normalized positive and negative PSI20 index daily returns r(t). Since the BHP probability density function appears in several other dissimilar phenomena, our result reveals a universal feature of the stock exchange markets.2011-01-01T00:00:00ZA geodiversidade e o património geológico
https://hdl.handle.net/10216/84718
Title: A geodiversidade e o património geológico2013-01-01T00:00:00ZUnknown costs in a duopoly with differentiated products
https://hdl.handle.net/10216/96367
Title: Unknown costs in a duopoly with differentiated products
Abstract: We consider a duopoly model with unknown costs. The firms' aims are to maximize their profits by choosing the levels of their outputs. The chooses are made simultaneously by both firms. In this paper, we suppose that each firm has two different technologies, and uses one of them following a probability distribution. The utilization of one or the other technology affects the unitary production cost. We show that this game has exactly one Bayesian Nash equilibrium. We analyze the advantages, for firms and for consumers, of using the technology with highest production cost versus the one with cheapest production cost. We also analyze the expected total quantity produced in each situation, which is of particular importance in the case that scanty natural resources are used in the production.
Description: We consider a duopoly model with unknown costs. The firms' aims are to maximize their profits by choosing the levels of their outputs. The chooses are made simultaneously by both firms. In this paper, we suppose that each firm has two different technologies, and uses one of them following a probability distribution. The utilization of one or the other technology affects the unitary production cost. We show that this game has exactly one Bayesian Nash equilibrium. We analyze the advantages, for firms and for consumers, of using the technology with highest production cost versus the one with cheapest production cost. We also analyze the expected total quantity produced in each situation, which is of particular importance in the case that scanty natural resources are used in the production.2007-01-01T00:00:00Z"Sistemas de verificação de dígitos" em "Treze Viagens pelo Mundo da Matemática", C.Sá e J.Rocha (eds.), UP
https://hdl.handle.net/10216/25779
Title: "Sistemas de verificação de dígitos" em "Treze Viagens pelo Mundo da Matemática", C.Sá e J.Rocha (eds.), UP2010-01-01T00:00:00ZInternal Waves
https://hdl.handle.net/10216/90317
Title: Internal Waves2010-01-01T00:00:00ZA Tourist's Choice Model
https://hdl.handle.net/10216/91302
Title: A Tourist's Choice Model
Abstract: Abstract We present a tourism model where the choice of a tourism resort by a tourist depends not only on the product offered in the resort, but depends also on the characteristics of the other tourists present in the resort. In order to explore the effect of the types of the tourists in the allocation of tourists across resorts, we introduce a game theoretical model and we describe some relevant Nash equilibria.
Description: Abstract We present a tourism model where the choice of a tourism resort by a tourist depends not only on the product offered in the resort, but depends also on the characteristics of the other tourists present in the resort. In order to explore the effect of the types of the tourists in the allocation of tourists across resorts, we introduce a game theoretical model and we describe some relevant Nash equilibria.2011-01-01T00:00:00ZTotal Mass TCI driven by Parametric Estimation
https://hdl.handle.net/10216/71245
Title: Total Mass TCI driven by Parametric Estimation
Abstract: This paper presents the Total Mass Target Controlled Infusion algorithm. The system comprises an On Line tuned Algorithm for Recovery Detection (OLARD) after an initial bolus administration and a Bayesian identification method for parametric estimation based on sparse measurements of the accessible signal. To design the drug dosage profile, two algorithms are here proposed. During the transient phase, an Input Variance Control (IVC) algorithm is used. It is based on the concept of TCI and aims to steer the drug effect to a predefined target value within an a priori fixed interval of time. After the steady state phase is reached the drug dose regimen is controlled by a Total Mass Control (TMC) algorithm. The mass control law for compartmental systems is robust even in the presence of parameter uncertainties. The whole system feasibility has been evaluated for the case of Neuromuscular Blockade (NMB) level and was tested both in simulation and in real cases.2009-01-01T00:00:00ZHausdorff Dimension versus Smoothness
https://hdl.handle.net/10216/92969
Title: Hausdorff Dimension versus Smoothness
Abstract: There is a one-to-one correspondence between C^{1+H} Cantor exchange systems that are C^{1+H} fixed points of renormalization and C^{1+H} diffeomorphisms f on surfaces with a codimension 1 hyperbolic attractor Λ that admit an invariant measure absolutely continuous with respect to the Hausdorff measure on Λ. However, there is no such C^{1+α} Cantor exchange system with bounded geometry that is a C^{1+α} fixed point of renormalization with regularity α greater than the Hausdorff dimension of its invariant Cantor set. The proof of the last result uses that the stable holonomies of a codimension 1 hyperbolic attractor Λ are not C^{1+θ} for θ greater than the Hausdorff dimension of the stable leaves of f intersected with Λ.
Description: There is a one-to-one correspondence between C^{1+H} Cantor exchange systems that are C^{1+H} fixed points of renormalization and C^{1+H} diffeomorphisms f on surfaces with a codimension 1 hyperbolic attractor Λ that admit an invariant measure absolutely continuous with respect to the Hausdorff measure on Λ. However, there is no such C^{1+α} Cantor exchange system with bounded geometry that is a C^{1+α} fixed point of renormalization with regularity α greater than the Hausdorff dimension of its invariant Cantor set. The proof of the last result uses that the stable holonomies of a codimension 1 hyperbolic attractor Λ are not C^{1+θ} for θ greater than the Hausdorff dimension of the stable leaves of f intersected with Λ.2008-01-01T00:00:00ZPatient Empowerment by the Means of Citizen-managed Electronic Health Records
https://hdl.handle.net/10216/95690
Title: Patient Empowerment by the Means of Citizen-managed Electronic Health Records
Abstract: With the advent of more sophisticated and comprehensive healthcare information systems, system builders are becoming more interested in patient interaction and what he can do to help to improve his own health care. Information systems play nowadays a crucial and fundamental role in hospital work-flows, thus providing great opportunities to introduce and improve upon "patient empowerment" processes for the personalization and management of Electronic Health Records (EHRs). In this paper, we present a patient's privacy generic control mechanisms scenarios based on the Extended OpenID (eOID), a user centric digital identity provider previously developed by our group, which leverages a secured OpenID 2.0 infrastructure with the recently released Portuguese Citizen Card (CC) for secure authentication in a distributed health information environment. eOID also takes advantage of Oauth assertion based mechanisms to implement patient controlled secure qualified role based access to his EHR, by third parties.2010-01-01T00:00:00Z