942 research outputs found
Data and pilot combining for composite GNSS signal acquisition
With the advent of new global navigation satellite systems (GNSS), such as the European Galileo, the Chinese Compass and the
modernized GPS, the presence of new modulations allows the use of special techniques specifically tailored to acquire and track
the new signals. Of particular interest are the new composite GNSS signals that will consist of two different components, the data
and pilot channels. Two strategies for the joint acquisition of the data and pilot components are compared. The first technique,
noncoherent combining, is fromthe literature and it is used as a comparison term, whereas the analysis of the second one, coherent
combining with sign recovery, represents the innovative contribution of this paper. Although the analysis is developed with respect
to the Galileo E1 Open Service (OS) modulation, the obtained results are general and can be applied to other GNSS signals
A new peer-to-peer aided acquisition approach exploiting C/N0 aiding
The aim of this paper is to present an acquisition strategy for Global Navigation Satellite System (GNSS) signals exploiting aiding information provided by GNSS receivers in a Peer-to-Peer (P2P) positioning system. This work sheds light on the benefits of sharing information regarding the received satellite signal power: the Carrier-to-Noise density ratio (C/N0) estimated by aiding peers relatively close to each other, is used to optimize signal acquisition capability in terms of detection performance as well as Mean Acquisition Time (MAT). The proposed approach has been validated and assessed using real data collected with an experimental setup in light indoor conditions and by means of simulations. The performance obtained has also been compared with an Assisted-GNSS (A-GNSS) like acquisition strategy, showing the benefits of the availability of C/N0 aiding information in terms of MAT. ©2010 IEEE
Smart Analogue Sampler for the Optical Module of a Cherenkov Neutrino Detector
A transient waveform sampler/recorder IC has been developed and realized in AMS C35B4 technology. This chip has been designed to fit the needs of a proposal for a front-end architecture for the readout of the anode signal of the photomultipliers in an underwater neutrino telescope. The design is based around a 3 channels x 32 cells switched capacitor array unit sampling its voltage inputs at 200MHz external clock rate and transferring the stored analogue voltage samples to its single analogue output at 1/10th of the sampling rate. This unit is replicated inside the ASIC providing 4 independent analogue sampling queues for signal transients up to 32 x 5 ns and a fifth unit storing transients up to 128 x 5 ns. A micro-pipelined unit, based on Muller C-gates, controls the 5 independent samplers. This paper briefly summarizes the complete front-end architecture and discusses in more detail the internal structure of the ASIC and its first functional tests
The role of blood clot in guided bone regeneration: Biological considerations and clinical applications with titanium foil
In Guided Bone Regeneration (GBR) materials and techniques are essential to achieve the expected results. Thanks to their properties, blood clots induce bone healing, maturation, differenti-ation and organization. The preferred material to protect the clot in Guided Bone Regeneration is the titanium foil, as it can be shaped according to the bone defect. Furthermore, its exposition in the oral cavity does not impair the procedure. We report on five clinical cases in order to explain the management of blood clots in combination with titanium foil barriers in different clinical settings. Besides being the best choice to protect the clot, the titanium foil represents an excellent barrier that is useful in GBR due to its biocompatibility, handling, and mechanical strength properties. The clot alone is the best natural scaffold to obtain the ideal bone quality and avoid the persistence of not-resorbed granules of filler materials in the newly regenerated bone. Even though clot contraction still needs to be improved, as it impacts the volume of the regenerated bone, future studies in GBR should be inspired by the clot and its fundamental properties
The MEV project: design and testing of a new high-resolution telescope for Muography of Etna Volcano
The MEV project aims at developing a muon telescope expressly designed for
the muography of Etna Volcano. In particular, one of the active craters in the
summit area of the volcano would be a suitable target for this experiment. A
muon tracking telescope with high imaging resolution was built and tested
during 2017. The telescope is a tracker based on extruded scintillating bars
with WLS fibres and featuring an innovative read-out architecture. It is
composed of three XY planes with a sensitive area of \SI{1}{m^2}; the angular
resolution does not exceeds \SI{0.4}{\milli\steradian} and the total angular
aperture is about \SI{45}{\degree}. A special effort concerned the design
of mechanics and electronics in order to meet the requirements of a detector
capable to work in a hostile environment such as the top of a tall volcano, at
a far distance from any facility. The test phase started in January 2017 and
ended successfully at the end of July 2017. An extinct volcanic crater (the
Monti Rossi, in the village of Nicolosi, about 15km from Catania) is the target
of the measurement. The detector acquired data for about 120 days and the
preliminary results are reported in this work
Can crumb rubber modifier effectively replace the use of polymer- modified bitumen in asphalt mixture?
Laboratory scale mechanical performances on six plant produced mixtures; three semi-dense surface courses and three dense binder courses modified with engineered crumb rubber (ECR) using the dry process are presented. The two types of mixtures produced and investigated fulfilled for the most part, the requirements of the Swiss and/or US standards regarding volumetric properties, water sensitivity and rutting. In advanced testing where no requirements exist, the dense ECR mixtures performed similar to the reference polymer modified mixtures and slightly worse for semi-dense mixtures in high temperature tests, where the binder becomes viscous in the rubber-binder composite and its ability to transfer loads is reduced. The ECR mixtures performed similarly or better than the reference in low temperature tests. Across the advanced testing data set, all obtained results were well within acceptable values for both ECR and reference polymer mixtures indicating that crumb rubber can effectively replace polymer in asphalt mixtures
Proposal, development and test of an analog front-end electronic board for Nemo telescope
The NEMO collaboration is involved in the R&D of the main technologies for the project of a km3 scale underwater neutrino telescope. The proposed detector is made up of thousands of Optical Modules (hereafter OM), spread over the entire volume for Cˇ erenkov light detection. Each OMis equipped with a photo multiplier tube (PMT) and an electronic circuit for data acquisition and transmission (DAQ-Board). This work points out the possible benefits of a hybrid solution based on an analog ASIC (Application Specific Integrated Circuit) employed for the analog signal acquisition and an FPGA (Field Programmable Gate Array), a digital programmable IC (Integrated Circuit) which performs the data acquisition and the data transmission
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