Showing papers by "Polytechnic University of Turin published in 2010"
TL;DR: Resilience function captures the effect of the disaster, but also the results of response and recovery, the effects of restoration and preparedness, and becomes an important tool in the decision process for both the policy makers and the engineering professionals.
1,002 citations
TL;DR: It was demonstrated that MVs contained ribonucleoproteins involved in the intracellular traffic of RNA and selected pattern of miRNAs, suggesting a dynamic regulation of RNA compartmentalization in MVs.
Abstract: Background: Cell-derived microvesicles (MVs) have been described as a new mechanism of cell-to-cell communication. MVs after internalization within target cells may deliver genetic information. Human bone marrow derived mesenchymal stem cells (MSCs) and liver resident stem cells (HLSCs) were shown to release MVs shuttling functional mRNAs. The aim of the present study was to evaluate whether MVs derived from MSCs and HLSCs contained selected micro-RNAs (miRNAs). Methodology/Principal Findings: MVs were isolated from MSCs and HLSCs. The presence in MVs of selected ribonucleoproteins involved in the traffic and stabilization of RNA was evaluated. We observed that MVs contained TIA, TIAR and HuR multifunctional proteins expressed in nuclei and stress granules, Stau1 and 2 implicated in the transport and stability of mRNA and Ago2 involved in miRNA transport and processing. RNA extracted from MVs and cells of origin was profiled for 365 known human mature miRNAs by real time PCR. Hierarchical clustering and similarity analysis of miRNAs showed 41 co-expressed miRNAs in MVs and cells. Some miRNAs were accumulated within MVs and absent in the cells after MV release; others were retained within the cells and not secreted in MVs. Gene ontology analysis of predicted and validated targets showed that the high expressed miRNAs in cells and MVs could be involved in multi-organ development, cell survival and differentiation. Few selected miRNAs shuttled by MVs were also associated with the immune system regulation. The highly expressed miRNAs in MVs were transferred to target cells after MV incorporation. Conclusions: This study demonstrated that MVs contained ribonucleoproteins involved in the intracellular traffic of RNA and selected pattern of miRNAs, suggesting a dynamic regulation of RNA compartmentalization in MVs. The observation that MV-highly expressed miRNAs were transferred to target cells, rises the possibility that the biological effect of stem cells may, at least in part, depend on MV-shuttled miRNAs. Data generated from this study, stimulate further functional investigations on the predicted target genes and pathways involved in the biological effect of human adult stem cells.
598 citations
TL;DR: In this article, a detailed Life Cycle Assessment (LCA) has been conducted on a low energy family house recently built in Northern Italy, which was claimed to be sustainable on the basis of its outstanding energy saving performances, an ex post LCA was set up to understand whether, and to what extent, the positive judgement could be confirmed in a life cycle perspective.
501 citations
TL;DR: In this paper, a comprehensive model to quantify disaster resilience of systems that is defined as the capability to sustain functionality and recover from losses generated by extreme events is presented. And the model combines loss estimation and recovery models and can be applied to critical facilities (e.g. hospitals, military buildings, etc.).
Abstract: This paper presents a comprehensive model to quantify disaster resilience of systems that is defined as the capability to sustain functionality and recover from losses generated by extreme events. The model combines loss estimation and recovery models and can be applied to critical facilities (e.g. hospitals, military buildings, etc.), as well as utility lifelines (e.g. electric power systems, transportation networks, water systems etc.) that are crucial to the response of recovery processes, decisions and policies. Current research trend leads toward the definition of complex recovery models that are able to describe the process over time and the spatial definition of recovery (e.g. meta-models for the case of health care facilities). The model has been applied to a network of hospitals in Memphis, Tennessee. The resilience framework can be used as a decision support tool to increase the resilience index of systems, such as health care facilities, and reduce disaster vulnerability and consequences.
453 citations
TL;DR: A comprehensive review of the literature in the main scientific journals provides historical perspective, methodological issues, applications, and most promising recent approaches as discussed by the authors, and a best-practices guideline is also outlined.
Abstract: Today, surface-wave analysis is widely adopted for building near-surface S-wave velocity models. The surface-wave method is under continuous and rapid evolution, also thanks to the lively scientific debate among different disciplines, and interest in the technique has increased significantly during the last decade. A comprehensive review of the literature in the main scientific journals provides historical perspective, methodological issues, applications, and most-promising recent approaches. Higher modes in the inversion and retrieval of lateral variations are dealt with in great detail, and the current scientific debate on these topics is reported. A best-practices guideline is also outlined.
407 citations
TL;DR: The relation between RCPVs and chance-constrained problems (CCP) is explored, showing that the optimal objective of an RCPV with the generic constraint removal rule provides, with arbitrarily high probability, an upper bound on the optimal objectives of a corresponding CCP.
Abstract: Random convex programs (RCPs) are convex optimization problems subject to a finite number $N$ of random constraints. The optimal objective value $J^*$ of an RCP is thus a random variable. We study the probability with which $J^*$ is no longer optimal if a further random constraint is added to the problem (violation probability, $V^*$). It turns out that this probability rapidly concentrates near zero as $N$ increases. We first develop a theory for RCPs, leading to explicit bounds on the upper tail probability of $V^*$. Then we extend the setup to the case of RCPs with $r$ a posteriori violated constraints (RCPVs): a paradigm that permits us to improve the optimal objective value while maintaining the violation probability under control. Explicit and nonasymptotic bounds are derived also in this case: the upper tail probability of $V^*$ is upper bounded by a multiple of a beta distribution, irrespective of the distribution on the random constraints. All results are derived under no feasibility assumptions on the problem. Further, the relation between RCPVs and chance-constrained problems (CCP) is explored, showing that the optimal objective $J^*$ of an RCPV with the generic constraint removal rule provides, with arbitrarily high probability, an upper bound on the optimal objective of a corresponding CCP. Moreover, whenever an optimal constraint removal rule is used in the RCPVs, then appropriate choices of $N$ and $r$ exist such that $J^*$ approximates arbitrarily well the objective of the CCP.
315 citations
04 Jul 2010
TL;DR: In this article, a single-phase inverter for distributed generation systems requiring power quality features, such as harmonic and reactive power compensation for grid-connected operation, is proposed, where the inverter controls the active power flow from the renewable energy source to the grid and also performs the nonlinear load current harmonic compensation keeping the grid current almost sinusoidal.
Abstract: Power electronic converters are commonly used for interfacing distributed generation systems to the electrical power network. This paper deals with a single-phase inverter for distributed generation systems requiring power quality features, such as harmonic and reactive power compensation for grid-connected operation. The idea is to integrate the DG unit functions with shunt active power filter capabilities. With the proposed approach, the inverter controls the active power flow from the renewable energy source to the grid and also performs the non-linear load current harmonic compensation keeping the grid current almost sinusoidal. The control scheme employs a current reference generator based on Sinusoidal Signal Integrator (SSI) and Instantaneous Reactive Power (IRP) theory together with a repetitive current controller. Experimental results obtained on a 4 kVA inverter prototype demonstrate the feasibility of the proposed solution.
301 citations
TL;DR: This brief review discusses the methods used to estimate the neural drive to muscles from the surface electromyogram (EMG).
298 citations
TL;DR: In this article, a hierarchical scheme is obtained by extending plates and shells Carrera's Unified Formulation (CUF) to beam structures and an N-order approximation via Mac Laurin's polynomials is assumed on the cross-section for the displacement unknown variables.
Abstract: This paper proposes several axiomatic refined theories for the linear static analysis of beams made of isotropic materials. A hierarchical scheme is obtained by extending plates and shells Carrera's Unified Formulation (CUF) to beam structures. An N-order approximation via Mac Laurin's polynomials is assumed on the cross-section for the displacement unknown variables. N is a free parameter of the formulation. Classical beam theories, such as Euler-Bernoulli's and Timoshenko's, are obtained as particular cases. According to CUF, the governing differential equations and the boundary conditions are derived in terms of a fundamental nucleo that does not depend upon the approximation order. The governing differential equations are solved via the Navier type, closed form solution. Rectangular and I-shaped cross-sections are accounted for. Beams undergo bending and torsional loadings. Several values of the span-to-height ratio are considered. Slender as well as deep beams are analysed. Comparisons with reference solutions and three-dimensional FEM models are given. The numerical investigation has shown that the proposed unified formulation yields the complete three-dimensional displacement and stress fields for each cross-section as long as the appropriate approximation order is considered. The accuracy of the solution depends upon the geometrical parameters of the beam and loading conditions.
283 citations
TL;DR: In this article, the authors present a special issue on groundwater-surface water (SW) interactions, which addresses the linkages between hydrology, biogeochemistry and ecology at nested scales and specifically accounts for small-scale spatial and temporal patterns of SW exchange.
246 citations
TL;DR: In this paper, a hierarchical beam element model based on the Carrera Unified Formulation (CUF) is presented, where the displacement components are expanded in terms of the section coordinates, (x,y), using a set of 1-D generalized displacement variables.
TL;DR: In this article, a combined Geographical Information System (GIS) and Life Cycle Assessment (LCA) model was developed using site-specific data and paying particular attention to land use, transportation and avoided landfill: crucial issues for sustainable planning and management.
TL;DR: In this paper, a set of algorithms based on pairwise ''gossip'' communications and updates is proposed to solve the average consensus problem on a network of digital links, and the convergence properties of such algorithms with the goal of answering two design questions, arising from the literature.
TL;DR: This review is an attempt to discuss the most performing methodologies that have been developed so far to perform computer-based segmentation and intima-media thickness (IMT) measurement of the carotid arteries in ultrasound images.
TL;DR: In this paper, the experimental and theoretical aspects of point-contact spectroscopy in superconductors are reviewed, and an experimental survey of the most recent applications of this technique is given.
Abstract: Point-contact spectroscopy was originally developed for the determination of the electron–phonon spectral function in normal metals. However, in the past 20 years it has become an important tool in the investigation of superconductors. As a matter of fact, point contacts between a normal metal and a superconductor can provide information on the amplitude and symmetry of the energy gap that, in the superconducting state, opens up at the Fermi level. In this paper we review the experimental and theoretical aspects of point-contact spectroscopy in superconductors, and we give an experimental survey of the most recent applications of this technique to anisotropic and multiband superconductors.
TL;DR: In this article, Li/LiFePO 4 cells with PVdF-HFP composite membranes swollen with a solution of LiTFSI in ether-functionalized pyrrolidinium-imide ionic liquid (PYRA 12O1 TFSI).
TL;DR: It is remarked that a near-optimal coverage of mobile users can be achieved only when the characteristics of vehicular mobility are known, and it is observed that simple heuristics provide near-Optimal results even in large-scale scenarios.
TL;DR: In this article, a novel TiO 2 nanoparticles (TNP) having a high specific surface area were successfully synthesized in a vortex reactor by sol-gel process with optimized operating parameters.
TL;DR: It is argued that the synoptic approach proposed here is valuable in both flood analysis and flood estimation.
TL;DR: A new multiscale modeling technique relies on a recently introduced measure-theoretic approach, which allows one to manage the microscopic and the macroscopic scale under a unique framework and in the resulting coupled model the two scales coexist and share information.
Abstract: In this paper a new multiscale modeling technique is proposed. It relies on a recently introduced measure-theoretic approach, which allows to manage the microscopic and the macroscopic scale under a unique framework. In the resulting coupled model the two scales coexist and share information. This allows to perform numerical simulations in which the trajectories and the density of the particles affect each other. Crowd dynamics is the motivating application throughout the paper.
TL;DR: In this article, a refined zigzag theory is presented for laminated-composite and sandwich plates that includes the kinematics of first-order shear-deformation theory as its baseline.
Abstract: A refined zigzag theory is presented for laminated-composite and sandwich plates that includes the kinematics of first-order shear-deformation theory as its baseline. The theory is variationally consistent and is derived from the virtual work principle. Novel piecewise-linear zigzag functions that provide a more realistic representation of the deformation states of transverse-shear-flexible plates than other similar theories are used. The formulation does not enforce full continuity of the transverse shear stresses across the plate's thickness, yet is robust. Transverse-shear correction factors are not required to yield accurate results. The theory is devoid of the shortcomings inherent in the previous zigzag theories including shear-force inconsistency and difficulties in simulating clamped boundary conditions, which have greatly limited the accuracy of these theories. This new theory requires only C0-continuous kinematic approximations and is perfectly suited for developing computationally efficient finite elements. The theory should be useful for obtaining relatively efficient, accurate estimates of structural response needed to design high-performance load-bearing aerospace structures
TL;DR: In this article, the authors highlight how rapid manufacturing (RM) of plastic parts combined with part redesign could have positive repercussion on cost saving, and compare the geometric and economic differences between IM and RM.
Abstract: Purpose – The purpose of this paper is to highlight how rapid manufacturing (RM) of plastic parts combined with part redesign could have positive repercussion on cost saving.Design/methodology/approach – Comparison between two different technologies for plastic part production, the traditional injection molding (IM) and the emergent RM, is done with consideration of both the geometric possibilities of RM and the economic aspect. From an extended literature review, the redesign guidelines and the cost model are identified and then applied to a component selected for its shape complexity. It is an assembly that was redesigned for RM purpose, in order to take advantage of additive manufacturing potentialities. The geometric and economic differences between IM and RM are discussed.Findings – This research evidences that currently in Western Europe RM combined with redesign can be economically convenient and competitive to IM for medium volume production of plastic parts. Consequently, this is a great opportun...
01 Jan 2010-Microsystem Technologies-micro-and Nanosystems-information Storage and Processing Systems
TL;DR: In this article, the shape of scavengers is optimized to increase the specific power generated per unit of scavenger volume by optimizing shape of the scavengers, and two optimized trapezoidal configurations are identified and analyzed.
Abstract: Compact autonomous power sources are one of the prerequisites for the development of wireless sensor networks. In this work vibration energy harvesting via piezoelectric resonant bimorph beams is studied. The available analytical approaches for the modeling of the coupled electromechanical behavior are critically evaluated and compared with a finite element (FEM) numerical model. The latter is applied to analyze thoroughly the stress and strain states, as well as to evaluate the resulting voltage and charge distributions in the piezoelectric layers. The aim of increasing the specific power generated per unit of scavenger volume is pursued by optimizing the shape of the scavengers. Two optimized trapezoidal configurations are hence identified and analyzed. An experimental set-up for the validation of the proposed numerical model and of the obtained optimized structures is developed. Results of a preliminary experimental assessment, confirming the improved performances of optimized scavengers, are finally given.
TL;DR: In this article, the authors describe the formulation adopted for the numerical simulation of the shaped metal deposition process (SMD) and the experimental work carried out at ITP Industry to calibrate and validate the proposed model.
TL;DR: The authors investigated the relationship between investment and regulatory regimes (incentive vs. rate-of-return regulation) for a sample of EU energy utilities from 1997 to 2007, and found that investment of incentive regulated firms appears highly sensitive to the X factor, consistent with efficiency and profit-seeking motivations.
Abstract: This paper investigates the relationship between investment and regulatory regimes (incentive vs. rate-of-return regulation) for a sample of EU energy utilities from 1997 to 2007. We control for the effect of firm ownership and for cross-country differences in the underlying energy demand and energy supply. To deal with potential endogeneity of the regulatory regime, we apply instrumental variable methods (2SLS and GMM). Our results show that investment rate is higher under incentive regulation than under rate of return regulation. Using original data on the regulatory tools (X factor and WACC), we find that investment of incentive regulated firms appears highly sensitive to the X factor, consistent with efficiency- and profit-seeking motivations. Electric utilities investment is also sensitive to the level and change in the weighted average cost of capital (WACC). Finally, we find that the positive relationship between private control and investment is not robust to IV estimations, suggesting that in Europe regulation may have reduced the differences between private and public firms’ incentives to invest.
TL;DR: This work has studied the contact formed between a smooth substrate and individual thin-film terminal elements of attachment pads evolved in insects, arachnids and reptiles, generalizing the critical role of terminal elements in biological fibrillar adhesion.
Abstract: To provide an explanation of why most biological hairy adhesive systems involved in locomotion rely on spatulate structures, we have studied the contact formed between a smooth substrate and individual thin-film terminal elements of attachment pads evolved in insects, arachnids and reptiles. The data obtained were analyzed using the Kendall peeling model, which demonstrated that an animal’s attachment ability grows with an overall length of the peeling line, which is the sum of widths of all thin-film elements participating in contact. This robust principle is found to manifest itself across 8 orders of magnitude in an overall peeling line ranging from 64 micrometres for a red spider mite to 1.8 kilometres for a Tokay gecko, generalizing the critical role of terminal elements in biological fibrillar adhesion.
TL;DR: It is demonstrated that near-infrared BSWs sustained by a silicon-based multilayer can be locally coupled and guided through dielectric ridges of nanometric thickness with low propagation losses.
Abstract: We present a direct evidence of Bloch surface waves (BSWs) waveguiding on ultrathin polymeric ridges, supported by near-field measurements. It is demonstrated that near-infrared BSWs sustained by a silicon-based multilayer can be locally coupled and guided through dielectric ridges of nanometric thickness with low propagation losses. Using a conventional prism-based configuration, we demonstrate a wavelength-selective BSW coupling inside and outside the ridge. Such a result can open interesting opportunities in surface wave-mediated sensing applications, where light could be selectively coupled in specific regions defined by nanometric reliefs.
TL;DR: This paper presents the results of a broad experimental study aimed at analyzing the impact on the total distribution cost of several parameters including customer distribution, satellites-location rules, depot location, number of satellites, mean accessibility of the satellites, and mean transportation cost between the satellites and the customers.
TL;DR: An advanced monitoring technique based on radar interferometry and implemented by using a ground-based instrumentation (GBInSAR) has been applied for monitoring the Beauregard Deep Seated Gravitational Slope Deformation as mentioned in this paper.
TL;DR: In this paper, the equivalence principle is applied to the inverse-source problem, where equivalent sources and/or flelds are computed on an arbitrary 3D closed surface from the knowledge of complex vector electric fleld data at a specifled (exterior) surface.
Abstract: This paper describes in detail difierent formulations of the inverse-source problem, whereby equivalent sources and/or flelds are to be computed on an arbitrary 3-D closed surface from the knowledge of complex vector electric fleld data at a specifled (exterior) surface. The starting point is the analysis of the formulation in terms of the Equivalence Principle, of the possible choices for the internal flelds, and of their practical impact. Love's (zero interior fleld) equivalence is the only equivalence form that yields currents directly related to the flelds on the reconstruction surface; its enforcement results in a pair of coupled integral equations. Formulations resulting in a single integral equation are also analyzed. The flrst is the single-equation, two-current formulation which is most common in current literature, in which no interior fleld condition is enforced. The single-current (electric or magnetic) formulation deriving from continuity enforcement of one fleld is also introduced and analyzed. Single-equation formulations result in a simpler implementation and a lower computational load than the dual-equation formulation, but numerical tests with synthetic data support the beneflts of the latter. The spectrum of the involved (discretized) operators clearly shows a relation with the theoretical Degrees of Freedom (DoF) of the measured fleld for the dual-equation formulation that guarantees extraction of these DoF; this is absent in the single-equation formulation. Examples conflrm that single- equation formulations do not yield Love's currents, as observed both with comparison with reference data and via energetic considerations. The presentation is concluded with a test on measured data which shows the stability and usefulness of the dual-equation formulation in a situation of practical relevance.