1,277 research outputs found

    Multiple Regimes in Cross-Region Growth Regressions with Spatial Dependence: A Parametric and a Semi-parametric Approach

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    This paper studies the distribution dynamics of development across European regions over the period 1975-2000. Regional development is measured in terms of both per capita GDP (Y/P) and its components: labour productivity and employment ratio (that in turn can be decomposed in terms of activity and unemployment rate). The Core/Periphery pattern in the European Union is firstly investigated and a comparative analysis in terms of income, productivity, employment and unemployment rates of the two partitions is carried out. Moreover, for each variable as well as for each partition, a nonparametric beta convergence analysis is applied. Synthetically, the results confirm the lack of regional convergence in per capita incomes, the presence of a negative quasi-linear relationship between growth rates and initial levels of labour productivity and a U-shaped relationship between growth rates and initial levels of unemployment rates. As it is well known, however, b-convergence analysis does not allow any test of multiple equilibria, such as “emerging twin peaks”, in the growth process. Equilibrium multiplicity can be properly assessed by using nonparametric techniques of analysis of the cross-regional distribution. In particular, a way to quantify the intra-distribution dynamics is the multivariate kernel, which estimates the joint density of regional income, productivity and (un)employment distribution at time t0 and t0+t. The results of this analysis suggest that over the period considered the regional growth pattern in Europe has followed a polarisation process rather than a convergence path. This appears particularly true in the case of per capita incomes and unemployment rates. Finally, in order to “explain” polarisation, conditional multivariate kernels are estimated. In particular, the role of spatial contiguity and regional sectoral specialisation is investigated.

    Regional unemployment and productivity in Europe

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    We analyze the relationship between regional unemployment and labour productivity in Europe, basing our empirical analysis on the predictions of a Neary-type General Oligopolistic Equilibrium trade model with efficiency-wages. Using semiparametric and dynamic panel data estimators and controlling for other factors, we give evidence of a nonlinear relationship between productivity and regional unemployment in Europe: with a level of productivity smaller than a certain threshold, this relationship is negative, while no relation occurs in the case of higher productivity regions. This evidence proves an important role of a wage-floor (induced by efficiency wages and exacerbated by institutional factors) under which the productivity gap cannot be compensated by a wage gap

    Il problema dell’egemonia nell’interpretazione gramsciana di Nicola Badaloni

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    This paper aims at retracing Nicola Badaloni's interpretation of Gramsci’s thought. We will try to show that, starting from an approach that can be described as “historicist”, Badaloni has gradually changed his reading, up to a wholly different position, characterized by the use of categories that are quite unrelated to Gramsci’s thinking. Badaloni ends up supporting a position that lies at the crossroads between the subjectivism typical of Western Marxism and scientism. Badaloni Nicola; Gramsci Antonio; Hegemony; Western Marxism; Scientism, Praxis

    A methodology to assess pedestrian crossing safety

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    Purpose: The safety level of a pedestrian crossing is affected by infrastructure characteristics and vehicular and pedestrian traffic level. This paper presents a methodology that allows assessing the safety level of a pedestrian crossing, regulated or not by traffic light, in an urban area according to the features of the crossing. Methods: A hierarchical structure representing factors influencing crossing safety has been developed and the relative contributions of each factor were calculated using AHP method. A composite index for crossing safety and specific indexes for main aspects included in the assessment have been developed. Results: Main assessment aspects are: Spatial and Temporal Design, Day-time and Night-time Visibility and Accessibility. Night-time Visibility resulted to have the higher weight (about 41%). Conclusion: Developed indexes allow ranking of pedestrian crossings and assigning intervention priorities, highlighting the aspects which are to be enhanced. The methodology has been used for the evaluation of 215 pedestrian crossings in 17 European cities for the Pedestrian Crossing Assessment Project co-financed by FIA Foundation. © 2010 The Author(s)

    Bifosfonati e disfunzione renale

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    Disphosphonates and renal impairmentOsteoporosis and chronic kidney disease (CKD) are two frequent pathological conditions in the adult and geriatric population and often coexist. These conditions ..

    Security at the Edge for Resource-Limited IoT Devices

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    The Internet of Things (IoT) is rapidly growing, with an estimated 14.4 billion active endpoints in 2022 and a forecast of approximately 30 billion connected devices by 2027. This proliferation of IoT devices has come with significant security challenges, including intrinsic security vulnerabilities, limited computing power, and the absence of timely security updates. Attacks leveraging such shortcomings could lead to severe consequences, including data breaches and potential disruptions to critical infrastructures. In response to these challenges, this research paper presents the IoT Proxy, a modular component designed to create a more resilient and secure IoT environment, especially in resource-limited scenarios. The core idea behind the IoT Proxy is to externalize security-related aspects of IoT devices by channeling their traffic through a secure network gateway equipped with different Virtual Network Security Functions (VNSFs). Our solution includes a Virtual Private Network (VPN) terminator and an Intrusion Prevention System (IPS) that uses a machine learning-based technique called oblivious authentication to identify connected devices. The IoT Proxy’s modular, scalable, and externalized security approach creates a more resilient and secure IoT environment, especially for resource-limited IoT devices. The promising experimental results from laboratory testing demonstrate the suitability of IoT Proxy to secure real-world IoT ecosystems

    An investigation of interregional trade network structures

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    We provide empirical evidence on the network structure of trade flows between European regions and discuss the theoretical underpinning of such a structure. First, we analyze EU regional trade data using Social Network Analysis. We describe the topology of this network and compute local and global centrality measures. Finally, we consider the distribution of higher order statistics, through the analysis of local clustering and main triadic structures in the triad census of interregional trade flows. In the theoretical part, we explore the relationship between trade costs and trade links. As shown by Behrens (2004, 2005a, 2005b) in a two-region linear new economic geography (NEG) model, trade costs and the local market size determine, even with finite trade costs, unconditional autarky and unilateral trade, that is, a one-directional flow from one region to the other. Following these contributions and guided by the empirical evidence, we clarify the relationship between market competition, trade costs and the patterns of trade in a three-region NEG model. We identify a larger set of trade network configurations other the three elementary ones that occur at the dyadic level between two regions (no trade, one-way trade, reciprocated two-way trade), and relate the model with the triad census

    Vigilància epidemiològica del Protocol de cribratge i diagnòstic de la malaltia de Chagas en dones embarassades llatinoamericanes i en els seus nadons: informe anual 2010

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    Embaràs; Chagas; TransmissióEmbarazo; Chagas; TransmisiónPregnancy; Chagas; TransmissionEn aquest informe, es presenten els resultats del primer any d'implementació del programa de cribratge de la malaltia de Chagas en dones embarassades llatinoamericanes i els seus nadons al territori català, on han col·laborat molts professionals sanitaris en representació dels centres de salut públics de Catalunya

    Relating Implicit Bias and Adversarial Attacks through Intrinsic Dimension

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    Despite their impressive performance in classification, neural networks are known to be vulnerable to adversarial attacks. These attacks are small perturbations of the input data designed to fool the model. Naturally, a question arises regarding the potential connection between the architecture, settings, or properties of the model and the nature of the attack. In this work, we aim to shed light on this problem by focusing on the implicit bias of the neural network, which refers to its inherent inclination to favor specific patterns or outcomes. Specifically, we investigate one aspect of the implicit bias, which involves the essential Fourier frequencies required for accurate image classification. We conduct tests to assess the statistical relationship between these frequencies and those necessary for a successful attack. To delve into this relationship, we propose a new method that can uncover non-linear correlations between sets of coordinates, which, in our case, are the aforementioned frequencies. By exploiting the entanglement between intrinsic dimension and correlation, we provide empirical evidence that the network bias in Fourier space and the target frequencies of adversarial attacks are closely tied

    Investigation of Strength and Formability of 6016 Aluminum Tailor Welded Blanks

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    The automotive industry is constantly looking for innovative techniques to produce lighter, more efficient, and less polluting vehicles to comply with the increasingly restrictive environmental regulations. One of the latest technologies, which is still developing, is based on the fabrication of the body-in-white and car parts through the stamping of aluminum tailor welded blanks. Tailor welded blanks (TWBs) are generally a combination of two/three metal sheets with different thicknesses and/or mechanical strengths, which are commonly laser butt-welded. Even though the aluminum TWBs have the main advantage of producing lightweight parts, their use is still limited by the lower formability than their parent materials and by the fact that laser welding of aluminum sheets still remains a process easily subjected to weld defects (i.e., internal porosity) and, hence, requires strict control of process parameters. This study has investigated the effects of the main laser welding process parameters (laser power, welding speed, and focus position) on the mechanical properties and formability of aluminum TWBs made of the 6xxx series. The research results show that the welding conditions highly influence the weldability of such alloys. Heat input over 70 J/mm is responsible for excessive porosity and molten pool (and consequent root concavity), which are responsible for the lowest mechanical strength and formability of joints. Differently, low amounts of imperfections have a limited influence on the mechanical behaviors of the TWB joints. Overall, a narrow weldability window is required to ensure welded joints with proper strength and limited or no porosity
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