5,596 research outputs found
A Technological Upgrade for the 21st Century and Beyond: Focusing on a Broad Interpretation of the Stored Communications Act
Territorial pressure and tourism contribution to GDP: The case of Italian regions
This article focuses on long-run co-movement between tourists' arrivals and per capita income with the aim of evaluating, through a macroeconomic perspective, whether its excessive increase can be detrimental to economic development. To this aim, GDP per capita in Italian NUTS2 regions is connected, through a dynamic panel cointegrating technique, to arrivals and to a measure of touristic congestion (tourism territorial pressure index). Results show that tourism contributes to the increase of
per capita GDP. However, when accounting for the congestion effect, the relation appears to be nonlinear, revealing a detrimental effect on growth driven by an excessive tourism pressure on territories
Absolute Poverty and Sound public Finance in the Eurozone
The respect of fiscal parameters is supposed to be â according to the official position of the European institutions â the best recipe for granting stability and growth. This optimistic view appears to be in contrast with the recent increase in poverty. The aim of this paper is to individuate the existence of a relation between governmentsâ decisions about fiscal policy and absolute poverty in 19 Eurozone countries from 2005 to 2017. The attempt is to answer the question as to whether the effect on growth generated by fiscal policy measures can account for the objective of poverty alleviation. The results support the conclusion that absolute poverty increases in the presence of a restrictive fiscal policy, while it decreases in the opposite case. During declining macroeconomic conditions, national governments belonging to the Eurozone appear to be unable to reconcile the objective of sound public finance with that of poverty alleviatio
Simultaneous transformation and rounding (STAR) models for integer-valued data
We propose a simple yet powerful framework for modeling integer-valued data,
such as counts, scores, and rounded data. The data-generating process is
defined by Simultaneously Transforming and Rounding (STAR) a continuous-valued
process, which produces a flexible family of integer-valued distributions
capable of modeling zero-inflation, bounded or censored data, and over- or
underdispersion. The transformation is modeled as unknown for greater
distributional flexibility, while the rounding operation ensures a coherent
integer-valued data-generating process. An efficient MCMC algorithm is
developed for posterior inference and provides a mechanism for adaptation of
successful Bayesian models and algorithms for continuous data to the
integer-valued data setting. Using the STAR framework, we design a new Bayesian
Additive Regression Tree (BART) model for integer-valued data, which
demonstrates impressive predictive distribution accuracy for both synthetic
data and a large healthcare utilization dataset. For interpretable
regression-based inference, we develop a STAR additive model, which offers
greater flexibility and scalability than existing integer-valued models. The
STAR additive model is applied to study the recent decline in Amazon river
dolphins
Arthropod-Borne Disease Control at a Glance: What's New on Drug Development?
Discovering and validating effective drugs to manage arthropod-borne diseases (ABD) is a timely and important research challenge with major impacts on real-world control programs at the time of quick resistance development in the targeted pathogens. This editorial highlights major research advances in the development of drugs for the control of vector-borne diseases, with a significant focus on malaria, Chagas disease, dengue, human African trypanosomiasis, leishmaniasis, and Zika. Broad reviews providing new insights on ABD recently published in Molecules have also been covered in "The Editors' pick" section
Design aspects of a CMC coating-like system for hot surfaces of aero engine components
Ceramic Matrix Composite (CMC) is an emerging material system that can be a game changer in the aerospace industry, both civil and military. CMCs components are, in fact, lighter and less prone to fatigue failure in a high temperature environment. However, at high temperatures, the diffusion of oxygen and water vapour inside the CMC can have detrimental effects. Therefore, the presence of protective coating is necessary to extend the life of CMC components. In the present work, a three-layers coating, consisting of a silicon bond (BND), adhesively bonded to the CMC, an Environment Barrier Coating (EBC) and a softer layer 3 (LAY3), is investigated for a CMC component. An aero-engine high pressure turbine seal segment was considered. Two design aspects are covered: (i) creep law is determined and calibrated in environment Abaqus from the experimental data of each coating layer available in the open literature, to provide a suitable instrument for the creep relaxation analyses of hot components; (ii) thickness sensitivity study of each layer of the coating is conducted to minimise the interface stresses of coating with substrate in order to mitigate cracking and removal/spalling phenomena when exposed to temperature gradients and to increase their service life. These two different aspects are combined together to predict the coating stress field as a function of service time
Analytic approach to solve a degenerate parabolic PDE for the Heston Model
We present an analytic approach to solve a degenerate parabolic problem associated to the Heston model, which is widely used in mathematical finance to derive the price of an European option on an risky asset with stochastic volatility. We give a variational formulation, involving weighted Sobolev spaces, of the second order degenerate elliptic operator of the parabolic PDE. We use this approach to prove, under appropriate assumptions on some involved unknown parameters, the existence and uniqueness of weak solutions to the parabolic problem on unbounded subdomains of the half-plane
An experimental assessment of fracture toughness in novel crimpâfreeâbased composite materials for aerospace applications
In the design of structural composite components for aerospace applications, durability and reliability play a very significant role. To assess the reliability of these material it is essential to carry out robust experimental tests on several specimens and under different loading conditions to allow the determination of fundamental fracture parameters. Fracture toughness, in particular, allows the quantification of the material strength to fracture. This work proposes a study on non-crimp fabric (NCF) together with a two-component epoxy resin. The selected system has been selected based on its suitability to produce aerospace-approved components using resin transfer molding (RTM) process. The fabric adopted is a SAERTEX NCF with very high modulus and strength, whereas the resin is BDP 4294. This work shows the methods, equipment, and results of an experimental campaign carried out to determine the fracture toughness of the manufactured NCF composite material. Finally, to quantify the fracture toughness of the NCF composite material, Mode I, II, Mixed Mode I-II, and translaminar fracture tests were also considered
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