336,094 research outputs found
Cartridge firing device designed for attachment, release and ejection of a satellite
The device functions were performed by a one-piece unit with resulting performances which were of interest regarding the satellite attachment and the accuracies of the path and velocity during separation and ejection. A gain in weight may be obtained relative to the conventional device used, i.e. maintenance belt, belt unlocking device, pusher spring, and cartridge fired pusher
Optimizing the Use of an Artificial Tongue-Placed Tactile Biofeedback for Improving Ankle Joint Position Sense in Humans
The performance of an artificial tongue-placed tactile biofeedback device for
improving ankle joint position sense was assessed in 12 young healthy adults
using an active matching task. The underlying principle of this system consists
of supplying individuals with supplementary information about the position of
the matching ankle relative to the reference ankle position through a
tongue-placed tactile output device generating electrotactile stimulation on a
36-point (6 X 6) matrix held against the surface of the tongue dorsum.
Precisely, (1) no electrodes were activated when both ankles were in a similar
angular position within a predetermined "angular dead zone" (ADZ); (2) 12
electrodes (2 X 6) of the anterior and posterior zones of the matrix were
activated (corresponding to the stimulation of the front and rear portion of
the tongue) when the matching ankle was in a too plantarflexed and dorsiflexed
position relative to the reference ankle, respectively. Two ADZ values of 0.5
degrees and 1.5 degrees were evaluated. Results showed (1) more accurate and
more consistent matching performances with than without biofeedback and (2)
more accurate and more consistent ankle joint matching performances when using
the biofeedback device with the smaller ADZ valu
Interpretable deep learning for guided structure-property explorations in photovoltaics
The performance of an organic photovoltaic device is intricately connected to
its active layer morphology. This connection between the active layer and
device performance is very expensive to evaluate, either experimentally or
computationally. Hence, designing morphologies to achieve higher performances
is non-trivial and often intractable. To solve this, we first introduce a deep
convolutional neural network (CNN) architecture that can serve as a fast and
robust surrogate for the complex structure-property map. Several tests were
performed to gain trust in this trained model. Then, we utilize this fast
framework to perform robust microstructural design to enhance device
performance.Comment: Workshop on Machine Learning for Molecules and Materials (MLMM),
Neural Information Processing Systems (NeurIPS) 2018, Montreal, Canad
Adaptive Importance Sampling in General Mixture Classes
In this paper, we propose an adaptive algorithm that iteratively updates both
the weights and component parameters of a mixture importance sampling density
so as to optimise the importance sampling performances, as measured by an
entropy criterion. The method is shown to be applicable to a wide class of
importance sampling densities, which includes in particular mixtures of
multivariate Student t distributions. The performances of the proposed scheme
are studied on both artificial and real examples, highlighting in particular
the benefit of a novel Rao-Blackwellisation device which can be easily
incorporated in the updating scheme.Comment: Removed misleading comment in Section
Current Amplification with Vertical Josephson Interferometers
It has long been recognized that a control current injected into the
section of a two-junction superconducting quantum interference device (SQUID)
is able to produce a change of its critical current , so that a current
gain can be identified. We investigate the circumstances under
which large gains can be achieved by using vertical Josephson interferometers
which are characterized by small loop inductances. We discuss the theory of
operation of such a novel device, its performances and its advantages with
respect to planar interferometers used in the previous works. Two potential
applications are addressed.Comment: 18 pages, 6 figure
Space optical instruments optimisation thanks to CMOS image sensor technology
Today, both CCD and CMOS sensors can be envisaged for nearly all visible sensors and instruments designed for space needs. Indeed, detectors built with both technologies allow excellent electro-optics performances to be reached, the selection of the most adequate device being driven by their functional and technological features and limits. The first part of the paper presents electro-optics characterisation results of CMOS Image Sensors (CIS) built with an optimised CMOS process, demonstrating the large improvements of CIS electro-optics performances. The second part reviews the advantages of CMOS technology for space applications, illustrated by examples of CIS developments performed by EADS Astrium and Supaéro/CIMI for current and short term coming space programs
Fiber-top atomic force microscope
We present the implementation of an atomic force microscope (AFM) based on fiber-top design. Our results demonstrate that the performances of fiber-top AFMs in contact mode are comparable to those of similar commercially available instruments. Our device thus represents an interesting\ud
alternative to existing AFMs, particularly for applications outside specialized research laboratories, where a compact, user-friendly, and versatile tool might often be preferred
Optimization of a pseudoelastic absorber for vibration mitigation
Damic vibration absorbers (DVAs) have received special attention in recent years due to their capability to reduce structural
vibrations of a primary structure. In this work, a DVA of the Tuned Mass Damper type based on a Shape Memory Alloy (SMA)
element with pseudoelastic behavior is considered. Owing to their rich thermomechanical response, SMAs can exhibit hysteresis
loops with rather different features in terms of overall energy dissipation and of pseudoelastic stiffness. As a first step towards the
comprehensive evaluation of the performances of such a device, the optimization of a TMD based on SMA devices with different
features is studied. Numerical simulations show that the size and the shape of the pseudoelastic loops can influence in a
significant way the performances of the DVA
Vibration control in plates by uniformly distributed PZT actuators interconnected via electric networks
In this paper a novel device aimed at controlling the mechanical vibrations
of plates by means of a set of electrically-interconnected piezoelectric
actuators is described. The actuators are embedded uniformly in the plate
wherein they connect every node of an electric network to ground, thus playing
the two-fold role of capacitive element in the electric network and of couple
suppliers. A mathematical model is introduced to describe the propagation of
electro-mechanical waves in the device; its validity is restricted to the case
of wave-forms with wave-length greater than the dimension of the piezoelectric
actuators used. A self-resonance criterion is established which assures the
possibility of electro-mechanical energy exchange. Finally the problem of
vibration control in simply supported and clamped plates is addressed; the
optimal net-impedance is determined. The results indicate that the proposed
device can improve the performances of piezoelectric actuationComment: 22 page
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