1,721,064 research outputs found
Completely regioselective hydroformylation of methyl N-acetamidoacrylate by chiral rhodium phosphine catalysts
No full textAsymmetric hydroformylation of N-acyl 1-aminoacrylic acid derivatives by rhodium/chiral diphosphine catalysts
No full textCHARGE AMPLIFIER DESIGN METHODOLOGY FOR PVDF-BASED TACTILE SENSORS
No full textThis paper proposes and describes a charge ampli ̄er-based interface electronics design methodology
approach for piezoelectric polymer tactile sensors to be used for humanoid robot
applications. The tactile sensor–consisting of a PVDF single sensor element–is illustrated, the
electromechanical thickness mode behavior is modeled and a fabricated prototype is presented.
The model allows associating the PVDF charge response to the e®ective load applied on the
outer surface of the sensor. The model is also used as a key in the proposed design methodology
to estimate the charge to be detected by the charge ampli ̄er. A case study based on the design
methodology approach is reported. The system (PVDF single taxel þ interface electronics) is
analyzed ̄rstly, considering it as ideal and then when the nonidealities come into play. A charge
ampli ̄er-based interface electronics prototype is also presented. The implementation is used to
validate the followed approach and then de ̄ning the design specs towards the dedicated IC
design. Some experimental results are also reported
FIGURE 3 in Comparative morphology of myrmecophilous immature stages of European Microdon species (Diptera: Syrphidae): updated identification key and new diagnostic characters
No full textFIGURE 3. Details of first instar larvae of M. myrmicae (A, C, E, G) and M. analis (B, D, F, H): A, B—dorsal microsculpture; C, D—ventral microsculpture; E, F—dorsal flower–like sensilla; G, H—ventral flower like sensilla. A, B, C, D = 100 µm; E, F, G = 10 µm; H = 30 µm. FS, flower-like sensilla.Published as part of Scarparo, Giulia, Wolton, Robert, Molfini, Marco, Pinna, Luigi Cao & Ulio, Andrea Di Gi-, 2020, Comparative morphology of myrmecophilous immature stages of European Microdon species (Diptera: Syrphidae): updated identification key and new diagnostic characters, pp. 348-370 in Zootaxa 4789 (2) on page 355, DOI: 10.11646/zootaxa.4789.2.2, http://zenodo.org/record/399083
N-(tert-Butoxycarbonyl)-2-(tert-butyldimethylsiloxy)pyrrole as a Glycine Anion Equivalent: a Flexible Enantioselective Access to Polyhydroxy-a-Amino Acids
No full textAnalysis of self-powered vibration-based energy scavenging system
No full textThis paper analyses a complete self-powered vibration based energy scavenging system. For the purpose of the analysis, the energy scavenging system (comprising of a SPICE model of Piezoelectric Bender Generator (PBG), an integrated semi-active bridge rectifier and a voltage regulator circuit) has been implemented in SPICE and presented in this paper. The semi-active bridge rectifier proposed in this paper uses Vertical Double-diffused MOS (VDMOS) transistors in place of standard diodes, to be suitable to withstand the high voltage values generated by PBGs. Using SPICE the analysis of the reciprocal interaction between PBG and scavenging system (in terms of stress, strain rate, mechanical and electrical powers at various loads and regulated voltages) is investigated. The simulation results of the semi-active bridge rectifier have shown an efficiency of the rectifier of about the 90 %. The simulation results of the whole system with optimized control circuits have shown how both the load and the regulated voltage can influence the behavior of stress and strain rate and vice versa. Comparisons of simulated stress and strain rate at various loads and regulated voltage values have shown an opposite behavior of the strain rate with respect to the stress. The simulation results of various powers - mechanical and electrical - from PBG to the load have shown the amount of mechanical power converted by the PBG into electrical that can be transferred to the load and that an optimal load exis
A Tensor-Based Pattern-Recognition Framework for the Interpretation of Touch Modality in Artificial Skin Systems
No full textArtificial skin systems support human–robot interactions
through touch. The interpretation of touch modalities
indeed represents a crucial component for the future development
of robots that can properly interact with humans. Independently
of the specific employed transducer, one of the key issues is
how to process the massively complex and high-dimensional
tactile data. In this paper, machine learning technologies (namely,
support vector machines and extreme learning machines)
support a pattern-recognition framework that can fully exploit
the tensor morphology of the tactile signal. Furthermore, a
practical strategy is provided to address the intricacies of the
training procedure. Experimental results show the effectiveness
of the proposed approach
A tensor-based approach to touch modality classification by using machine learning
No full textThe use of piezoelectric sensor arrays to measure contact forces has been extensively studied in connection
to robotics. In this research, Polyvinylidene Fluoride (PVDF) has been used for direct measurement
of the mechanical stress and large bandwidth electromechanical transduction. Additionally, a machine
learning algorithm has been specifically designed to deal with the inherent tensor morphology of raw
tactile data. An experiment involving 70 participants has been organized to collect the output signals
under different modalities of touch. The proposed pattern-recognition system showed good accuracy in
performing touch classification in a three-class classification experiment, opening interesting scenarios
for the application of tensor-based models to support human–robot interactions
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