Search results for " array"
showing 10 items of 895 documents
A Dual-Core Coprocessor with Native 4D Clifford Algebra Support
2012
Geometric or Clifford Algebra (CA) is a powerful mathematical tool that is attracting a growing attention in many research fields such as computer graphics, computer vision, robotics and medical imaging for its natural and intuitive way to represent geometric objects and their transformations. This paper introduces the architecture of CliffordCoreDuo, an embedded dual-core coprocessor that offers direct hardware support to four-dimensional (4D) Clifford algebra operations. A prototype implementation on an FPGA board is detailed. Experimental results show a 1.6× average speedup of CliffordCoreDuo in comparison with the baseline mono-core architecture. A potential cycle speedup of about 40× o…
Embedded Coprocessors for Native Execution of Geometric Algebra Operations
2016
Clifford algebra or geometric algebra (GA) is a simple and intuitive way to model geometric objects and their transformations. Operating in high-dimensional vector spaces with significant computational costs, the practical use of GA requires dedicated software and/or hardware architectures to directly support Clifford data types and operators. In this paper, a family of embedded coprocessors for the native execution of GA operations is presented. The paper shows the evolution of the coprocessor family focusing on the latest two architectures that offer direct hardware support to up to five-dimensional Clifford operations. The proposed coprocessors exploit hardware-oriented representations o…
A Programmable Networked Processing Node for 3D Brain Vessels Reconstruction
2011
Real-time 3D imaging represents a developing trend in medical imaging. However, most of the 3D medical imaging algorithms are computationally intensive. In this paper, a programmable networked node for 3D brain vessels reconstruction is proposed. Starting from 2D PC-MRA (Phase-Contrast Magnetic Resonance Angiography) sequences, the node is able to generate the 3D brain vasculature using the MIP (Maximum Intensity Projection) algorithm. The node has been prototyped on the Celoxica RC203E board, equipped with a Virtex II FPGA, to get the advantages of an hardware implementation, reaching a better throughput with respect to analogous software implementations. Its generality and programmable ca…
Lipid and apoprotein composition of HDL in partial or complete CETP deficiency
2012
Hyperalphalipoproteinemia, as observed in patients who are either homozygous or heterozygous for cholesteryl ester transfer protein (CETP) deficiency, has been shown to be associated with striking changes in apolipoprotein size distribution, namely, of high-density lipoprotein (HDL) and HDL-like particles. We compared the effect of varying degrees of CETP activity on the HDL apolipoprotein profile in Caucasian CETP-deficient subjects and following pharmacological decrease in CETP activity, using Size Exclusion Chromatography followed by Reverse Phase Protein Array (SEC RPA). The main HDL-associated apolipoproteins (Apo), i.e. ApoA-I, ApoA-II, ApoC-I, and ApoC-III, co-eluted with the HDL pea…
THE FINGERPRINT OF THE HUMAN GASTROINTESTINAL TRACT MICROBIOTA: A HYPOTHESIS OF MOLECULAR MAPPING
2017
The precise etiology of Inflammatory Bowel Disease (IDB) remains unclear and several factors are believed to play a role in its development and progression, including the composition of microbial communities resident in the gastrointestinal tract. Human intestinal microbiota are extensive with at least 15,000-36,000 bacterial species. However, thanks to the new development in sequencing and molecular taxonomic methodologies, our understanding of the microbiota population composition, dynamics, and ecology has greatly increased. Intestinal microbiota play a critical role in the maintenance of the host intestinal barrier homeostasis, while dysbiosis, which involves reduction in the microbiome…
Fabrication of Electrical Contacts on Pyramid-Shaped NTD-Ge Microcalorimeters Using Free-Standing Shadow Masks
2011
In our effort to fabricate arrays of germanium microcalorimeters for X-ray detection, a truncated square-based pyramid shape has been identified as a suitable geometry for the sensors. It allows to obtain a uniform current spreading across each sensor, and represents a good compromise between having a large support area for the radiation absorber and for maintaining an overall small bolometer volume. This three-dimensional geometry, however, does not allow to create the electrical contacts for the sensors using a regular photoresist-based lift-off metallization process. In this paper we show how to deposit metal contacts on the lateral faces of the pyramidal sensors by metal evaporation thr…
A New Model for Sigma-Delta Modulator Oriented to Digitally Controlled DC/DC Converter
2007
Recent research activities have shown the feasibility and advantages of using digital controller ICs specifically developed for high-frequency switching converters, highlighting a challenging future trend in Switched-mode power supplies (SMPS) applications. Up to a few years ago, the application of digital control for SMPS was impractical due to the high cost and low performance of DSP and microcontroller systems, even if the advantages that digital controllers offer were well known, such as immunity to analog component variations and ability to implement sophisticated control schemes and system diagnostics. Digital controller ICs potentially offer other advantages from the integrated desig…
Information Processing Schemes Based on Monolayer Protected Metallic Nanoclusters
2011
Nanostructures are potentially useful as building blocks to complement future electronics because of their high versatility and packing densities. The fabrication and characterization of particular nanostructures and the use of new theoretical tools to describe their properties are receiving much attention. However, the integration of these individual systems into general schemes that could perform simple tasks is also necessary because modern electronics operation relies on the concerted action of many basic units. We review here new conceptual schemes that can allow information processing with ligand or monolayer protected metallic nanoclusters (MPCs) on the basis of the experimentally de…
On the performance of multi-GPU-based expert systems for acoustic localization involving massive microphone arrays
2015
Sound source localization is an important topic in expert systems involving microphone arrays, such as automatic camera steering systems, human-machine interaction, video gaming or audio surveillance. The Steered Response Power with Phase Transform (SRP-PHAT) algorithm is a well-known approach for sound source localization due to its robust performance in noisy and reverberant environments. This algorithm analyzes the sound power captured by an acoustic beamformer on a defined spatial grid, estimating the source location as the point that maximizes the output power. Since localization accuracy can be improved by using high-resolution spatial grids and a high number of microphones, accurate …
Energy balance in single exposure multispectral sensors
2013
International audience; Recent simulations of multispectral sensors are based on a simple Gaussian model, which includes filters transmittance and substrate absorption. In this paper we want to make the distinction between these two layers. We discuss the balance of energy by channel in multispectral solid state sensors and propose an updated simple Gaussian model to simulate multispectral sensors. Results are based on simulation of typical sensor configurations.