For a biological agent operating under environmental pressure, energy consumption and reaction times are of critical importance. Similarly, engineered systems are optimized for short time-to-solution ...and low energy-to-solution characteristics. At the level of neuronal implementation, this implies achieving the desired results with as few and as early spikes as possible. With time-to-first-spike coding, both of these goals are inherently emerging features of learning. Here, we describe a rigorous derivation of a learning rule for such first-spike times in networks of leaky integrate-and-fire neurons, relying solely on input and output spike times, and show how this mechanism can implement error backpropagation in hierarchical spiking networks. Furthermore, we emulate our framework on the BrainScaleS-2 neuromorphic system and demonstrate its capability of harnessing the system’s speed and energy characteristics. Finally, we examine how our approach generalizes to other neuromorphic platforms by studying how its performance is affected by typical distortive effects induced by neuromorphic substrates.Spiking neural networks promise fast and energy-efficient information processing. The ‘time-to-first-spike’ coding scheme, where the time elapsed before a neuron’s first spike is utilized as the main variable, is a particularly efficient approach and Göltz and Kriener et al. demonstrate that error backpropagation, an essential ingredient for learning in neural networks, can be implemented in this scheme.
We present our experimental set-up and results for a THz beam profiling system based on a mechanical spatial light modulator (SLM) for one pixel sensing. By placing a synthetic aperture into the path ...of a propagating THz beam we achieved the optical ON/OFF keying of its various intensity components. Further, by successively expose a series of predesigned binary masks we manage to encode within their features the beam spatial distribution. The masks used are of a predefined size and can be designed for different resolutions. Our approach eliminates the need of using an array of pixels for detection while still maintaining the high sensitivity and dynamic range of one detector.
•A single pixel camera for THz domain with mechanical encoding mask is proposed.•2.5THz methanol laser beam was analyzed for three different profile patterns.•Information about beam power, waist dimensions and beam shape was revealed.
Effects of strong longitudinal color electric fields, shadowing, and quenching on the production of prompt open charm mesons (D0, D+, D , D ) in central Pb + Pb collisions at = 2.76 TeV are ...investigated within the framework of the HIJING/B v2.0 model. We compute the nuclear modification factor RPbPbD, and show that the above nuclear effects constitute important dynamical mechanisms in the description of experimental data. The strength of color fields (as characterized by the string tension ), partonic energy loss and jet quenching process lead to a suppression factor consistent with recent published data. Predictions for beauty mesons are presented. In addition, ratios of strange to non-strange prompt charm mesons in central Pb + Pb and minimum bias (MB) collisions at 2.76 TeV are also discussed. MB collisions which constitute a theoretical baseline in our calculations are studied at centre of mass energies = 2.76 TeV and 7 TeV.
Original Abstract: La mise en uvre de certaines strategies telles que le cadre DPSIR peut conduire a une meilleure coordination au niveau local et national en vue de preserver la biodiversite et la ...qualite des masses d'eau. La sensibilite variable des macroinvertebres benthiques a ete utilisee pour determiner la maniere dont ces communautes sont influencees par le developpement socio-economique, modifiant finalement la biodiversite. La presente etude vise a presenter une liste concernant les differentes especes de trichopteres identifies en phase larvaire dans le site Natura 2000 de la partie inferieure des gorges de la riviere Mures, pour attirer l'attention sur les menaces existantes concernant la qualite des ecosystemes aquatiques en fonction des especes de trichopteres reperees et egalement de proposer une serie de mesures de conservation considerees comme essentielles pour le developpement durable des complexes socio-ecologiques dans la zone cible. Les points d'echantillonnage sont 13 stations utilisees pour identifier les especes de trichopteres en phase larvaire. On a identifie 20 especes appartenant a 7 familles. Les especes les plus frequentes ont ete Hydropsyche instabilis et Hydropsyche fulvipes (echantillons qualitatifs) et Hydropsyche instabilis, Hydropsyche fulvipes et Ecclisopteryx madida (echantillons quantitatifs), respectivement.
The Time-of-Flight (TOF) subsystem, one of the core detectors of the CBM experiment, is dedicated to the identification of all charged hadrons produced in beam-target interaction. The targeted system ...time resolution of 80 ps and an efficiency above 90% should be maintained at a particle flux up to 30 kHz/cm2 in the region of low polar angles. In order to cope with these challenging requirements, CBM-TOF wall will be equipped with Multi-Gap Resistive Plate Counters with Multi-Strip readout (MSMGRPC). Our R&D activity has been focused on the development of a MSMGRPC prototype for the most demanding region of the CBM-TOF wall, the region of low polar angles (from 2.5° to ∼12° around the beam pipe). The results obtained in heavy ion in-beam tests have demonstrated the performances of the developed prototypes in conditions of exposure of the whole active area to high flux and high multiplicity reaction products. The latest developed prototypes have an optimized design which fulfills simultaneously two important requirements for MSMGRPCs, the granularity for the inner zone of the CBM-TOF subdetector and the impedance matching to the front-end electronics. Based on the obtained in-beam test results and the architecture of the developed prototypes, a modular structure of 12 units called modules is proposed. A total number of 470 MSMGRPCs (~30000 readout channels) assures an uniform coverage of the active area.
We present measurements of the excitation function of elliptic flow at midrapidity in Au+Au collisions at beam energies from 0.09 to 1.49 GeV per nucleon. For the integral flow, we discuss the ...interplay between collective expansion and spectator shadowing for three centrality classes. A complete excitation function of transverse momentum dependence of elliptic flow is presented for the first time in this energy range, revealing a rapid change with incident energy below 0.4 AGeV, followed by an almost perfect scaling at the higher energies. The equation of state of compressed nuclear matter is addressed through comparisons to microscopic transport model calculations.
The Time Of Flight (TOF) subsystem is one of the main detectors of the CBM experiment. The TOF wall in conjunction with Silicon Tracking System (STS) is foreseen to identify charged hadrons, i.e. ...pions, kaons and protons, with a full azimuthal coverage at 2.50 - 250 polar angles. A system time resolution of at least 80 ps, including all contributions, such as electronics jitter and the resolution of the time reference system, is required. Such a performance should be maintained up to a counting rate larger than 30 kHz/cm2 at the most inner region of TOF wall. Our R&D activity has been focused on the development of two-dimensional position sensitive Multi-gap Resistive Plate Counter (MRPC) prototypes for the forward region of the CBM-TOF subdetector, the most demanding zone in terms of granularity and counting rate. The in-beam tests using secondary particles produced in 30 GeV/u Pb ion collisions on a Pb target at SPS - CERN aimed to test the performance of these prototypes in conditions similar to the ones expected at SIS100 at FAIR. The performance of the prototypes is studied in conditions of exposure of the whole active area of the chamber to high multiplicity of reaction products. The results show that this type of MRPC fulfill the challenging requirements of the CBM-TOF wall. Therefore, such an architecture is recommended as basic solution for CBM-TOF inner zone.
The implementation of some strategies such as DPSIR framework may lead to a better coordination at both local and national level with a view to maintaining biodiversity and quality of water bodies. ...The different sensibility of the benthic macroinvertebrates has been used in determining the manner in which these communities are being influenced by the socio-economic development, in the end modifying the biodiversity. The present study aims at presenting a list concerning the different species of caddisflies identified in the larva phase in Natura 2000 site Lower Gorge of Mureş river, to draw attention on existing threats regarding the quality of aquatic ecosystems based on the indentified caddisflies species and also to propose a series of conservation measures considered essential to the sustainable development of socio-ecological complexes in the target area. The sample collecting points were represented by 13 stations used to identify the caddisflies species in the larva phase. There were identified 20 species included in a number of 7 families. The most frequent species were Hydropsyche instabilis and Hydropsyche fulvipes (qualitative samples), and Hydropsyche instabilis, Hydropsyche fulvipes and Ecclisopteryx madida (quantitative samples), respectively.
La mise en œuvre de certaines stratégies telles que le cadre DPSIR peut conduire à une meilleure coordination au niveau local et national en vue de préserver la biodiversité et la qualité des masses d’eau. La sensibilité variable des macroinvertébrés benthiques a été utilisée pour déterminer la manière dont ces communautés sont influencées par le développement socio-économique, modifiant finalement la biodiversité. La présente étude vise à présenter une liste concernant les différentes espèces de trichoptères identifiés en phase larvaire dans le site Natura 2000 de la partie inférieure des gorges de la rivière Mures, pour attirer l’attention sur les menaces existantes concernant la qualité des écosystèmes aquatiques en fonction des espèces de trichoptères repérées et également de proposer une série de mesures de conservation considérées comme essentielles pour le développement durable des complexes socio-écologiques dans la zone cible. Les points d’échantillonnage sont 13 stations utilisées pour identifier les espèces de trichoptères en phase larvaire. On a identifié 20 espèces appartenant à 7 familles. Les espèces les plus fréquentes ont été Hydropsyche instabilis et Hydropsyche fulvipes (échantillons qualitatifs) et Hydropsyche instabilis, Hydropsyche fulvipes et Ecclisopteryx madida (échantillons quantitatifs), respectivement.
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