Numerical Stochastic Perturbation Theory in the Schr\"odinger Functional

The Schr\"odinger functional (SF) is a powerful and widely used tool for the treatment of a variety of problems in renormalization and related areas. Albeit offering many conceptual advantages, one major downside of the SF scheme is the fact that perturbative calculations quickly become cumbersome with the inclusion of higher orders in the gauge coupling and hence the use of an automated perturbation theory framework is desirable. We present the implementation of the SF in numerical stochastic perturbation theory (NSPT) and compare first results for the running coupling at two loops in pure SU(3) Yang-Mills theory with the literature.Comment: 7 pages, 2 figures, 2 tables, presented at the 31st International Symposium on Lattice Field Theory - LATTICE 2013 July 29 - August 3, 2013 Mainz, German

Essere Natura: L'universo sinfonico e il delicato empirismo di Spinoza

Attraverso i dubbi che Tschirnhaus rivolge a Spinoza circa l’impercettibilità degli attributi e la distinzione dell'essenza dell'intelletto divino con l'essenza dell'intelletto umano, il presente saggio si propone di studiare il rapporto fra totalità e parte e il senso dell’immanenza nell’ontologia spinoziana, con particolare attenzione alla diade implicazione-esplicazione che ne permette il funzionamento. La comunanza formale propria dell’immanenza, la quale fonda l’implicazione e l’esplicazione, risulta il concetto chiave per comprendere a un tempo lo statuto sinfonico dell’universo modale, in cui ogni cosa singolare richiama l'altra e il tutto, e il delicato empirismo che costituisce il terzo genere di conoscenza.Through the doubts Tschirnhaus poses to Spinoza about the imperceptibility of the attributes and the distiction of the divine intellect's essence and the human intellect's essence , this essays proposes a study of the relationship between the totality and its parts and the sense of immanence in Spinoza's ontology, with a keen eye on the implication-explication dyad which allows it to funcyion. The formal communion proper to immanence, which grounds implication and explication, turns out to be the key concept to understand both the symphonic nature of the universe, in which each one thing recalls all other and the whole, and the delicate empiricism that defines the third kind of knowledge

Signalling Design in Sensor-Assisted mmWave Communications for Cooperative Driving

Millimeter-Wave (mmWave) Vehicle-To-Vehicle (V2V) communications are a key enabler for connected and automated vehicles, as they support the low-latency exchange of control signals and high-resolution imaging data for maneuvering coordination. The employment of mmWave V2V communications calls for Beam Alignment and Tracking (BAT) procedures to ensure that the antenna beams are properly steered during motion. The conventional beam sweeping approach is known to be unsuited for the high vehicular mobility and its large overhead reduces transmission efficiency. A promising solution to reduce BAT signalling foresees the integration of V2V communication systems with on-board vehicle sensors. We focus on a cooperative sensor-assisted architecture for mmWave V2V communications in line of sight, where vehicles exchange the estimate of antenna position and its uncertainty to compute the optimal beam direction and dimension. We analyze and compare different signalling strategies for sharing the information on antenna estimate, evaluating the tradeoff between signalling overhead and performance loss for different position and uncertainty encoding strategies. Main attention is given to differential quantization on both the antenna position and uncertainty. Analyses over realistic urban mobility trajectories suggest that differential approaches introduce a negligible performance loss while significantly reducing the BAT signalling communication overhead

Climate change will increase the potential conflict between skiing and high-elevation bird species in the Alps

Aim: To assess the extent of the possible future conflict between skiing and biodiversity driven by climate change, human adaptation and species' distribution shifts. Location: Italian Alps. Methods: We assessed the extent of the possible future conflict between skiing and biodiversity by predicting locations likely to be suitable for both skiing and for high-elevation birds in the Italian Alps by modelling ski-piste and species presence in relation to climate, topography and habitat. Potential conflict was assessed by comparing the overlap of areas projected as suitable for skiing and those suitable for four high-elevation bird species under different scenarios of climate change for the year 2050. Results: Areas suitable for both ski-pistes and birds were projected to contract towards upper elevations, which for birds resulted in an average decrease of 58\u201367% of suitable area. The degree of overlap between species and skiing was projected to increase, especially for the most valuable sites, that is, those hosting the most species, or the most threatened species. Main conclusions: Given the alarming range contractions forecast for high-elevation species, and the potential impact of ski-pistes on those species, it is essential to safeguard high-mountain grasslands against negative effects of ski development. An effective conservation strategy at a landscape scale needs to consider prevention of ski-piste construction in sites of high conservation value. The approach developed here provides a means by which such a strategy could be formulated, and which could be potentially applied elsewhere to investigate the effect of human adaptation on biodiversity

RF-Assisted Free-Space Optics for 5G Vehicle-to-Vehicle Communications

Vehicle-to-Vehicle (V2V) communications are being proposed, tested and deployed to improve road safety and traffic efficiency. However, the automotive industry poses strict requirements for safety-critical applications, that call for reliable, low latency and high data rate communications. In this context, it is widely agreed that both Radio-Frequency (RF) technologies at mmWaves and Free-Space Optics (FSO) represent promising solutions, although their performances are severely degraded by transmitter-receiver misalignment due to the challenging high-mobility conditions. By combining RF and FSO technologies, this paper proposes a FSO-based V2V communication system where the pointing coordinates of laser sources are based on vehicle's information exchanged over a reliable low-rate RF link. Numerical simulations demonstrate that such compensation mechanism is mandatory to counteract the unavoidable misalignments induced by vehicle dynamics, and thus to enable FSO technology for V2V communications even in high mobility scenarios.Comment: Accepted in IEEE ICC 201

WITHDRAWN: Experimental evidence of the wind-induced bias of precipitation gauges using Particle Image Velocimetry and particle tracking in the wind tunnel

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