175,518 research outputs found
Microsystems technology: objectives
This contribution focuses on the objectives of microsystems technology (MST). The reason for this is two fold. First of all, it should explain what MST actually is. This question is often posed and a simple answer is lacking, as a consequence of the diversity of subjects that are perceived as MST. The second reason is that a map of the somewhat chaotic field of MST is needed to identify sub-territories, for which standardization in terms of system modules an interconnections is feasible. To define the objectives a pragmatic approach has been followed. From the literature a selection of topics has been chosen and collected that are perceived as belonging to the field of MST by a large community of workers in the field (more than 250 references). In this way an overview has been created with `applications¿ and `generic issues¿ as the main characteristics
Distinguishing Posed and Spontaneous Smiles by Facial Dynamics
Smile is one of the key elements in identifying emotions and present state of
mind of an individual. In this work, we propose a cluster of approaches to
classify posed and spontaneous smiles using deep convolutional neural network
(CNN) face features, local phase quantization (LPQ), dense optical flow and
histogram of gradient (HOG). Eulerian Video Magnification (EVM) is used for
micro-expression smile amplification along with three normalization procedures
for distinguishing posed and spontaneous smiles. Although the deep CNN face
model is trained with large number of face images, HOG features outperforms
this model for overall face smile classification task. Using EVM to amplify
micro-expressions did not have a significant impact on classification accuracy,
while the normalizing facial features improved classification accuracy. Unlike
many manual or semi-automatic methodologies, our approach aims to automatically
classify all smiles into either `spontaneous' or `posed' categories, by using
support vector machines (SVM). Experimental results on large UvA-NEMO smile
database show promising results as compared to other relevant methods.Comment: 16 pages, 8 figures, ACCV 2016, Second Workshop on Spontaneous Facial
Behavior Analysi
Advanced radar absorbing ceramic-based materials for multifunctional applications in space environment
In this review, some results of the experimental activity carried out by the authors on advanced composite materials for space applications are reported. Composites are widely employed in the aerospace industry thanks to their lightweight and advanced thermo-mechanical and electrical properties. A critical issue to tackle using engineered materials for space activities is providing two or more specific functionalities by means of single items/components. In this scenario, carbon-based composites are believed to be ideal candidates for the forthcoming development of aerospace research and space missions, since a widespread variety of multi-functional structures are allowed by employing these materials. The research results described here suggest that hybrid ceramic/polymeric structures could be employed as spacecraft-specific subsystems in order to ensure extreme temperature withstanding and electromagnetic shielding behavior simultaneously. The morphological and thermo-mechanical analysis of carbon/carbon (C/C) three-dimensional (3D) shell prototypes is reported; then, the microwave characterization of multilayered carbon-filled micro-/nano-composite panels is described. Finally, the possibility of combining the C/C bulk with a carbon-reinforced skin in a synergic arrangement is discussed, with the aid of numerical and experimental analyses
Simulation of main plasma parameters of a cylindrical asymmetric capacitively coupled plasma micro-thruster using computational fluid dynamics
Computational fluid dynamics (CFD) simulations of a radio-frequency (13.56 MHz)
electrothermal capacitively coupled plasma (CCP) micro-thruster have been performed
using the commercial CFD-ACE+ package. Standard operating conditions of a 10W,
1.5 Torr argon discharge were used to compare with previously obtained experimental
results for validation. Results show that the driving force behind plasma production
within the thruster is ion-induced secondary electrons ejected from the surface of the
discharge tube, accelerated through the sheath to electron temperatures up to 33.5 eV.
The secondary electron coefficient was varied to determine the effect on the discharge,
with results showing that full breakdown of the discharge did not occur for coefficients
less than or equal to 0.01
Streamers, sprites, leaders, lightning: from micro- to macroscales
"Streamers, sprites, leaders, lightning: from micro- to macroscales" was the
theme of a workshop in October 2007 in Leiden, The Netherlands; it brought
researchers from plasma physics, electrical engineering and industry,
geophysics and space physics, computational science and nonlinear dynamics
together around the common topic of generation, structure and products of
streamer-like electric breakdown. The present cluster issue collects relevant
articles within this area; most of them were presented during the workshop. We
here briefly discuss the research questions and very shortly review the papers
in the cluster issue, and we also refer to a few recent papers in other
journals.Comment: Editorial introduction for the cluster issue on "Streamers, sprites
and lightning" in J. Phys. D, 13 pages, 74 reference
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