RBF approximation of large datasets by partition of unity and local stabilization

We present an algorithm to approximate large dataset by Radial Basis Function (RBF) techniques. The method couples a fast domain decomposition procedure with a localized stabilization method. The resulting algorithm can efficiently deal with large problems and it is robust with respect to the typical instability of kernel methods

Oscillatory dynamics in nanocavities with noninstantaneous Kerr response

We investigate the impact of a finite response time of Kerr nonlinearities over the onset of spontaneous oscillations (self-pulsing) occurring in a nanocavity. The complete characterization of the underlying Hopf bifurcation in the full parameter space allows us to show the existence of a critical value of the response time and to envisage different regimes of competition with bistability. The transition from a stable oscillatory state to chaos is found to occur only in cavities which are detuned far off-resonance, which turns out to be mutually exclusive with the region where the cavity can operate as a bistable switch

Causes of Adult Splanchnic Vein Thrombosis in the Mediterranean Area

The term splanchnic vein thrombosis encompasses Budd-Chiari syndrome (BCS), extrahepatic portal vein obstruction (EHPVO), and mesenteric vein thrombosis

Decentralised cooperation and its potential for local democratic governance: the experience of Trentino decentralised cooperation

Since the early 1990s Local Authorities (LAs) have stepped into the international development cooperation arena and in many European countries Decentralised Cooperation (DC) has become increasingly relevant as a new development cooperation modality that has great potential in terms of promoting sustainable development and local democratic governance. DC in international development is a relatively new phenomenon and its full potential is not yet fully known. Based on the findings of a two year long evaluative research of four DC programmes implemented by Trentino in Northern Italy in partnership with three municipalities in the Balkans and a rural district in Mozambique, this paper contributes to the literature on DC policies and practices in highlighting a scarcely analysed issue: the contribution of DC to local democratic governance and the possible reasons as to why DC, despite its potential, faces challenges that hinder its capacity to effectively contribute to decentralised governanc

Decentralised cooperation and its potential for local democratic governance: the experience of Trentino decentralised cooperation

Since the early 1990s Local Authorities (LAs) have stepped into the international development cooperation arena and in many European countries Decentralised Cooperation (DC) has become increasingly relevant as a new development cooperation modality that has great potential in terms of promoting sustainable development and local democratic governance. DC in international development is a relatively new phenomenon and its full potential is not yet fully known. Based on the findings of a two year long evaluative research of four DC programmes implemented by Trentino in Northern Italy in partnership with three municipalities in the Balkans and a rural district in Mozambique, this paper contributes to the literature on DC policies and practices in highlighting a scarcely analysed issue: the contribution of DC to local democratic governance and the possible reasons as to why DC, despite its potential, faces challenges that hinder its capacity to effectively contribute to decentralised governanc

GNSS-based dam monitoring: The application of a statistical approach for time series analysis to a case study

Dams are one of the most important engineering works of the current human society, and it is crucial to monitor and obtain analytical data to log their conditions, predict their behavior and, eventually, receive early warnings for planning interventions and maintenance activities. In this context, GNSS-based point displacement monitoring is nowadays a consolidated technique that is able to provide daily millimeter level accuracy, even with less sophisticated and less expensive single-frequency equipment. If properly designed, daily records of such monitoring systems produce time series that, when long enough, allow for an accurate reconstruction of the geometrical deformation of the structure, thus guiding semi-automatic early warning systems. This paper focuses on the procedure for the GNSS time series processing with a statistical approach. In particular, real-world times series collected from a dam monitoring test case are processed as an example of data filtering. A remove–restore technique based on a collocation approach is applied here. Basically, it consists of an initial deterministic modeling by polynomials and periodical components through least squares adjustment and Fourier transform, respectively, followed by a stochastic modeling based on empirical covariance estimation and a collocation approach. Filtered time series are interpreted by autoregressive models based on environmental factors such as air or water temperature and reservoir water level. Spatial analysis is finally performed by computing correlations between displacements of the monitored points, as well as by visualizing the overall structure deformation in time. Results positively validate the proposed data processing workflow, providing useful hints for the implementation of automatic early warning systems in the framework of structural monitoring based on continuous displacement measurements

Transverse strength of railway tracks : Part 3. Multiple scenarios test field

© Gruppo Italiano Frattura 2014. This is an Open Access article distributed in accordance with the terms of the Creative Commons Attribution (CC BY 4.0) license, which permits others to distribute, remix, adapt and build upon this work, for commercial use, provided the original work is properly cited. See: https://creativecommons.org/licenses/by/4.0/In the present paper the design and construction choices of a test field for the ballast lateral resistance measurement, in order to produce data useful for the development of a numerical model able to simulate the service critical conditions of a continuous welded rail track, are described. Some construction details described herein allow to better understand the methodological approach followed in the design of experiments, the tests management philosophy as well as of the accuracy achieved in their implementation.Peer reviewe