A high-precision liDAR-based method for surveying and classifying coastal notches

Formation of notches is an important process in the erosion of seaside cliffs. Monitoring of coastal notch erosion rate and processes has become a prime research focus for many coastal geomorphologists. Observation of notch erosion rate considers a number of characteristics, including cliff collapse risk, distinction of historical sea levels, and recognition of ongoing erosional mechanisms. This study presents new approaches for surveying and classifying marine notches based on a high-precision light detection and ranging (LiDAR)-based experiment performed on a small region of a coastal cliff in southern Portugal. A terrestrial LiDAR scanner was used to measure geometrical parameters and surface roughness of selected notches, enabling their classification according to shape and origin. The implemented methodology proved to be a highly effective tool for providing an unbiased analysis of marine morphodynamic processes acting on the seaside cliffs. In the analyzed population of voids carved into Miocene calcarenites in a coastal cliff section, two types of notch morphology were distinguished, namely U-shaped and V-shaped. The method presented here provides valuable data for landscape evaluation, sea-level changes, and any other types of analyses that rely on the accurate interpretation of cliff morphological features.National Science Centre [UMO-2015/17/D/ST10/02191

Spatio-temporal conjecture for diffusion

We present here a conjecture about the equivalence between the noise density of states of a system governed by a generalized Langevin equation and the fluctuation in the energy density of states in a Hamiltonian system. We present evidence of this for a disordered Heisenberg system.Comment: 6 pages, 1 figure. Submitted to Physica

On the use of spectral element methods for under-resolved simulations of transitional and turbulent flows

The present thesis comprises a sequence of studies that investigate the suitability of spectral element methods for model-free under-resolved computations of transitional and turbulent flows. More specifically, the continuous and the discontinuous Galerkin (i.e. CG and DG) methods have their performance assessed for under-resolved direct numerical simulations (uDNS) / implicit large eddy simulations (iLES). In these approaches, the governing equations of fluid motion are solved in unfiltered form, as in a typical direct numerical simulation, but the degrees of freedom employed are insufficient to capture all the turbulent scales. Numerical dissipation introduced by appropriate stabilisation techniques complements molecular viscosity in providing small-scale regularisation at very large Reynolds numbers. Added spectral vanishing viscosity (SVV) is considered for CG, while upwind dissipation is relied upon for DG-based computations. In both cases, the use of polynomial dealiasing strategies is assumed. Focus is given to the so-called eigensolution analysis framework, where numerical dispersion and diffusion errors are appraised in wavenumber/frequency space for simplified model problems, such as the one-dimensional linear advection equation. In the assessment of CG and DG, both temporal and spatial eigenanalyses are considered. While the former assumes periodic boundary conditions and is better suited for temporally evolving problems, the latter considers inflow / outflow type boundaries and should be favoured for spatially developing flows. Despite the simplicity of linear eigensolution analyses, surprisingly useful insights can be obtained from them and verified in actual turbulence problems. In fact, one of the most important contributions of this thesis is to highlight how linear eigenanalysis can be helpful in explaining why and how to use spectral element methods (particularly CG and DG) in uDNS/iLES approaches. Various aspects of solution quality and numerical stability are discussed by connecting observations from eigensolution analyses and under-resolved turbulence computations. First, DG’s temporal eigenanalysis is revisited and a simple criterion named "the 1% rule" is devised to estimate DG’s effective resolution power in spectral space. This criterion is shown to pinpoint the wavenumber beyond which a numerically induced dissipation range appears in the energy spectra of Burgers turbulence simulations in one dimension. Next, the temporal eigenanalysis of CG is discussed with and without SVV. A modified SVV operator based on DG’s upwind dissipation is proposed to enhance CG’s accuracy and robustness for uDNS / iLES. In the sequence, an extensive set of DG computations of the inviscid Taylor-Green vortex model problem is considered. These are used for the validation of the 1% rule in actual three-dimensional transitional / turbulent flows. The performance of various Riemann solvers is also discussed in this infinite Reynolds number scenario, with high quality solutions being achieved. Subsequently, the capabilities of CG for uDNS/iLES are tested through a complex turbulent boundary layer (periodic) test problem. While LES results of this test case are known to require sophisticated modelling and relatively fine grids, high-order CG approaches are shown to deliver surprisingly good quality with significantly less degrees of freedom, even without SVV. Finally, spatial eigenanalyses are conducted for DG and CG. Differences caused by upwinding levels and Riemann solvers are explored in the DG case, while robust SVV design is considered for CG, again by reference to DG’s upwind dissipation. These aspects are then tested in a two-dimensional test problem that mimics spatially developing grid turbulence. In summary, a point is made that uDNS/iLES approaches based on high-order spectral element methods, when properly stabilised, are very powerful tools for the computation of practically all types of transitional and turbulent flows. This capability is argued to stem essentially from their superior resolution power per degree of freedom and the absence of (often restrictive) modelling assumptions. Conscientious usage is however necessary as solution quality and numerical robustness may depend strongly on discretisation variables such as polynomial order, appropriate mesh spacing, Riemann solver, SVV parameters, dealiasing strategy and alternative stabilisation techniques.Open Acces

Threads and Or-Parallelism Unified

One of the main advantages of Logic Programming (LP) is that it provides an excellent framework for the parallel execution of programs. In this work we investigate novel techniques to efficiently exploit parallelism from real-world applications in low cost multi-core architectures. To achieve these goals, we revive and redesign the YapOr system to exploit or-parallelism based on a multi-threaded implementation. Our new approach takes full advantage of the state-of-the-art fast and optimized YAP Prolog engine and shares the underlying execution environment, scheduler and most of the data structures used to support YapOr's model. Initial experiments with our new approach consistently achieve almost linear speedups for most of the applications, proving itself as a good alternative for exploiting implicit parallelism in the currently available low cost multi-core architectures.Comment: 17 pages, 21 figures, International Conference on Logic Programming (ICLP 2010

Baumol’s cost disease in the health care sector

The concern for the impact of the Health Care costs in private and public spending has been increasing because of its effect on the country’s financial stability. Therefore, several drivers of Health Care Expenditure have been studied. However, one of its most relevant drivers is Baumol’s cost disease. Baumol (1967) defines the cost disease as the difference between the wage growth in the overall economy and productivity growth in the services sector, such as the health care sector. This excess in wages causes the unit costs in the health care sector to increase over time. In order to understand if there is enough margin for policymakers to establish effective policies to control for the rise in health care costs, this thesis studies the impact of Baumol’s cost disease in this sector in OECD countries. To do so, I define an instrument, the adjusted Baumol variable, to measure Baumol’s cost disease and apply it to a panel data set containing 18 OECD member countries from 1970 to 2016. The results found show that the adjusted Baumol variable is explaining from 20% to 80% of the increase in Health Care expenditure, depending on the definition of the Baumol sector. These results may imply that policymakers still have some margin to implement policies since the rise in Health Care expenditure is partially explained by Baumol’s cost disease.O impacto do aumento dos custos na despesa pública e privada relativos ao Sector da Saúde tem sido motivo de preocupação, uma vez que estes afetam a estabilidade financeira do país. Assim, foram estudados vários fatores influenciadores dos gastos associados ao sector da Saúde. De acordo com os resultados obtidos, a doença de custos de Baumol foi um dos fatores com maior impacto no crescimento dos referidos custos. Baumol (1967) define a doença dos custos como sendo a diferença entre o crescimento dos salários na Economia e o crescimento da produtividade no sector dos serviços, como é o caso do sector da saúde. Portanto, esta diferença faz com que os custos unitários no sector de saúde aumentem ao longo do tempo. Esta tese estuda o impacto da doença dos custos de Baumol no sector da Saúde com o intuito de compreender se existe espaço suficiente para a introdução de políticas eficazes na contenção do aumento dos custos associados a este sector. Portanto, foi definido um instrumento – variável de Baumol ajustada – para medir a doença de custos de Baumol e, posteriormente, foi aplicada com um conjunto de dados em painel, contendo 18 países membros da OCDE de 1970 a 2016. Os resultados encontrados mostram que a referida variável explica entre 20% a 80% do aumento dos gastos com a saúde dependendo da definição do sector de Baumol. Conclui-se que existe margem para implementar políticas pois o aumento das de saúde não é totalmente explicado pela doença dos custos de Baumol

Improving communication skill training in patient centered medical practice for enhancing rational use of laboratory tests: The core of bioinformation for leveraging stakeholder engagement in regulatory science.

Requests for laboratory tests are among the most relevant additional tools used by physicians as part of patient's health problemsolving. However, the overestimation of complementary investigation may be linked to less reflective medical practice as a consequence of a poor physician-patient communication, and may impair patient-centered care. This scenario is likely to result from reduced consultation time, and a clinical model focused on the disease. We propose a new medical intervention program that specifically targets improving the patient-centered communication of laboratory tests results, the core of bioinformation in health care. Expectations are that medical students training in communication skills significantly improve physicians-patient relationship, reduce inappropriate use of laboratorial tests, and raise stakeholder engagement

Dissipative maps at the chaos threshold: Numerical results for the single-site map

We numerically study, at the edge of chaos, the behaviour of the sibgle-site map $x_{t+1}=x_t-x_t/(x_t^2+\gamma^2)$, where $\gamma$ is the map parameter.Comment: 8 pages with 4 figures, submitted to Physica

La constitucionalización del Derecho y el régimen jurídico-administrativo

El presente estudio investiga en qué medida el fenómeno de la constitucionalización del Derecho administrativo promueve una relectura de los principios fundamentales de la materia desde la óptica de la Constitución, ayudando a la reestructuración dogmática del papel central ocupado por el hombre en el ordenamiento jurídico y de la dimensión material de la democracia, con una modificación sustancial de la relación entre Administración y administrado.This study researches to what extent the phenomenon of constitutionalization of administrative law promotes a re-reading of the fundamental principies of the matter from the perspective of the Constitution, helping to dogmatically restructure the central role occupied by individuals in the legal system and the material dimension of democracy, with a substantial change in the relationship between administration and administered