75 research outputs found

    Point clouds turned into finite elements: The umbrella vault of Castel Masegra

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    The paper presents a workflow for finite element model generation from point clouds acquired via photogrammetry and laser scanning. The case study is a room with an umbrella vault in Castel Masegra, located in Sondrio (Italy). The complexity of the room required an accurate geometric survey from a set of dense point clouds, from which a detailed BIM as well as 2D drawings were generated. Finally, a tetrahedral mesh was derived from the geometric model and was used to run a finite element analysis. The aim of this work is to describe the procedure developed and illustrate the main challenges found

    A Multi-Channel Low-Power System-on-Chip for in Vivo Recording and Wireless Transmission of Neural Spikes

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    This paper reports a multi-channel neural spike recording system-on-chip with digital data compression and wireless telemetry. The circuit consists of 16 amplifiers, an analog time-division multiplexer, a single 8 bit analog-to-digital converter, a digital signal compression unit and a wireless transmitter. Although only 16 amplifiers are integrated in our current die version, the whole system is designed to work with 64, demonstrating the feasibility of a digital processing and narrowband wireless transmission of 64 neural recording channels. Compression of the raw data is achieved by detecting the action potentials (APs) and storing 20 samples for each spike waveform. This compression method retains sufficiently high data quality to allow for single neuron identification (spike sorting). The 400 MHz transmitter employs a Manchester-Coded Frequency Shift Keying (MC-FSK) modulator with low modulation index. In this way, a 1.25 Mbit/s data rate is delivered within a limited band of about 3 MHz. The chip is realized in a 0.35 um AMS CMOS process featuring a 3 V power supply with an area of 3.1x 2.7 mm2. The achieved transmission range is over 10 m with an overall power consumption for 64 channels of 17.2 mW. This figure translates into a power budget of 269uW per channel, in line with published results but allowing a larger transmission distance and more efficient bandwidth occupation of the wireless link. The integrated circuit was mounted on a small and light board to be used during neuroscience experiments with freely-behaving rats. Powered by 2 AAA batteries, the system can continuously work for more than 100 hours allowing for long-lasting neural spike recordings

    Indici foraggeri di specie legnose ed erbacee alpine per il bestiame caprino

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    Foraging indexes of wooden and herbaceous alpine species for goat livestock. Foraging indexes are easier and cheaper than chemical analysis to value phytocoenosis\u2019 foraging rate. Once the productive contribution or the covering ratio of all the species are known, the foraging valueof the phytocoenosis is the weighted average of the foraging value of the single species. Altough various indexes are available for cattle, there\u2019s no one for the other domestic livestocks. No doubt this is a gap, considering the differences in diet and grazing behaviour of the different grazing species. This work aims to partially fill this gap. A first list of values for goat livestock is proposed. The list reflects numerous surveys carried out in different locations of Lombardian Alps. A hundred of wooden and herbaceous species growing in the mountain and sub-alpine belt were observed

    BIM FROM LASER CLOUDS AND FINITE ELEMENT ANALYSIS: COMBINING STRUCTURAL ANALYSIS AND GEOMETRIC COMPLEXITY

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    This paper describes the use of BIM models derived from point clouds for structural simulation based on Finite Element Analysis (FEA). Although BIM interoperability has reached a significant level of maturity, the density of laser point clouds provides very detailed BIM models that cannot directly be used in FEA software. The rationalization of the BIM towards a new finite element model is not a simple reduction of the number of nodes. The interconnections between the different elements and their materials require a particular attention: BIM technology includes geometrical aspects and structural considerations that allow one to understand and replicate the constructive elements and their mutual interaction. The information must be accurately investigated to obtain a finite element model suitable for a complete and detailed structural analysis. The aim of this paper is to prove that a drastic reduction of the quality of the BIM model is not necessary. Geometric data encapsulated into dense point clouds can be taken into consideration also for finite element analysis

    Sistemi zootecnici delle aree alpine

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    Viene presentato il panorama italiano sulla zootecnia alpina, evidenziandone i punti di forza e le criticit\ue0 attraverso le varie aree dell'arco alpino

    Optimization of cognitive assessment in Parkinsonisms by applying artificial intelligence to a comprehensive screening test.

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    The assessment of cognitive deficits is pivotal for diagnosis and management in patients with parkinsonisms. Low levels of correspondence are observed between evaluations assessed with screening cognitive tests in comparison with those assessed with in-depth neuropsychological batteries. A new tool, we named CoMDA (Cognition in Movement Disorders Assessment), was composed by merging Mini-Mental State Examination (MMSE), Montreal Cognitive Assessment (MoCA), and Frontal Assessment Battery (FAB). In total, 500 patients (400 with Parkinson's disease, 41 with vascular parkinsonism, 31 with progressive supranuclear palsy, and 28 with multiple system atrophy) underwent CoMDA (level 1-L1) and in-depth neuropsychological battery (level 2-L2). Machine learning was developed to classify the CoMDA score and obtain an accurate prediction of the cognitive profile along three different classes: normal cognition (NC), mild cognitive impairment (MCI), and impaired cognition (IC). The classification accuracy of CoMDA, assessed by ROC analysis, was compared with MMSE, MoCA, and FAB. The area under the curve (AUC) of CoMDA was significantly higher than that of MMSE, MoCA and FAB (p < 0.0001, p = 0.028 and p = 0.0007, respectively). Among 15 different algorithmic methods, the Quadratic Discriminant Analysis algorithm (CoMDA-ML) showed higher overall-metrics performance levels in predictive performance. Considering L2 as a 3-level continuous feature, CoMDA-ML produces accurate and generalizable classifications: micro-average ROC curve, AUC = 0.81; and AUC = 0.85 for NC, 0.67 for MCI, and 0.83 for IC. CoMDA and COMDA-ML are reliable and time-sparing tools, accurate in classifying cognitive profile in parkinsonisms.This study has been registered on ClinicalTrials.gov (NCT04858893)

    Large-scale heterogeneous cattle grazing affects plant diversity and forage value of Alpine species-rich Nardus pastures

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    In Europe, the decline in agriculture in traditional mountain farming areas has caused abandonment, or irregular grazing, of less accessible pastures. In the Italian Alps, we studied plant diversity, forage value and trophic traits in six large-scale heterogeneously grazed Nardus pastures, in their central and peripheral parts, and across the montane, lower and upper subalpine zones. Seventy cover-abundance floristic relevés were performed in randomly located permanent plots, half at the pasture edge (M-plots) and half in their central part (C-plots). Plant diversity varied significantly with respect to the distance from the edge, being higher in M-plots because of shrub invasion as a consequence of reduced cattle pressure. Nardus cover was slightly higher in C-plots and negatively related to plant diversity. Forage value was lower in M-plots and negatively correlated with the cover of Nardus and woody species, implying that different grazing pressure was negatively influencing sward productivity. Differences in trophic traits of swards between C- and M-plots existed mostly as trends. Forage value significantly decreased in the lower subalpine and montane pastures, which are further grazed in late summer. Heterogeneous grazing management was therefore exerting positive effects on plant diversity and negative effects on forage value. Results are discussed in the context of future management recommendations. © 2011 Blackwell Publishing Ltd
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