9,704 research outputs found
Drift Correction Methods for gas Chemical Sensors in Artificial Olfaction Systems: Techniques and Challenges
In this chapter the authors introduce the main challenges faced when developing drift correction techniques and will propose a deep overview of state-of-the-art methodologies that have been proposed in the scientific literature trying to underlying pros and cons of these techniques and focusing on challenges still open and waiting for solution
FLARE: A design environment for FLASH-based space applications
Designing a mass-memory device (i.e., a solid-state recorder) is one of the typical issues of mission-critical space system applications. Flash-memories could be used for this goal: a huge number of parameters and trade-offs need to be explored. Flash-memories are nonvolatile, shock-resistant and power-economic, but in turn have different drawback: e.g., their cost is higher than normal hard disk and the number of erasure cycles is bounded. Moreover space environment presents various issues especially because of radiations: different and quite often contrasting dimensions need to be explored during the design of a flash-memory based solid-state recorder. No systematic approach has so far been proposed to consider them all as a whole: as a consequence a novel design environment currently under development is aimed at supporting the design of flash-based mass-memory device for space application
Flash-memories in Space Applications: Trends and Challenges
Nowadays space applications are provided with a processing power absolutely overcoming the one available just a few years ago. Typical mission-critical space system applications include also the issue of solid-state recorder(s). Flash-memories are nonvolatile, shock-resistant and power-economic, but in turn have different drawbacks. A solid-state recorder for space applications should satisfy many different constraints especially because of the issues related to radiations: proper countermeasures are needed, together with EDAC and testing techniques in order to improve the dependability of the whole system. Different and quite often contrasting dimensions need to be explored during the design of a flash-memory based solid- state recorder. In particular, we shall explore the most important flash-memory design dimensions and trade-offs to tackle during the design of flash-based hard disks for space application
A programmable BIST architecture for clusters of Multiple-Port SRAMs
This paper presents a BIST architecture, based on a single microprogrammable BIST processor and a set of memory wrappers, designed to simplify the test of a system containing many distributed multi-port SRAMs of different sizes (number of bits, number of words), access protocol (asynchronous, synchronous), and timin
Exploring Design Dimensions in Flash-based Mass-memory Devices
Mission-critical space system applications present several issues: a typical one is the design of a mass-memory device (i.e., a solid- state recorder). This goal could be accomplished by using flash- memories: the exploration of a huge number of parameters and trade-offs is needed. On the one hand flash-memories are nonvolatile, shock-resistant and power-economic, but on the other hand their cost is higher than normal hard disk, the number of erasure cycles is bounded and other different drawbacks have to be considered. In addition space environment presents various issues especially because of radiations: the design of a flash- memory based solid-state recorder implies the exploration of different and quite often contrasting dimensions. No systematic approach has so far been proposed to consider them all as a whole: as a consequence the design of flash-based mass-memory device for space applications is intended to be supported by a novel design environment currently under development and refinemen
Design Issues and Challenges of File Systems for Flash Memories
This chapter discusses how to properly address the issues of using NAND flash memories as mass-memory devices from the native file system standpoint. We hope that the ideas and the solutions proposed in this chapter will be a valuable starting point for designers of NAND flash-based mass-memory devices
Obstructive sleep apnea syndrome in the pediatric age: the role of the dentist
Sleep disordered breathing in children designates a wide spectrum of respiratory disorders characterized by partial or complete obstruction of the upper airways. It ranges from primary snoring, its mildest clinical manifestation, to obstructive sleep apnea syndrome (OSAS): complete obstruction of the upper airways with cessation of airflow. The aim of this paper is to highlight the roles of the pediatric dentist and the orthodontist in the therapeutic approach to pediatric OSAS as a "sentinel" who can detect early signs of the disease for immediate referral to the otolaryngologist and as an active participant in therapy
Precise measurement of the 222Rn half-life: a probe to monitor the stability of radioactivity
We give the results of a study on the 222Rn decay we performed in the Gran
Sasso Laboratory (LNGS) by detecting the gamma rays from the radon progeny. The
motivation was to monitor the stability of radioactivity measuring several
times per year the half-life of a short lifetime (days) source instead of
measuring over a long period the activity of a long lifetime (tens or hundreds
of years) source. In particular, we give a possible reason of the large
periodical fluctuations in the count rate of the gamma rays due to radon inside
a closed canister which has been described in literature and which has been
attributed to a possible influence of a component in the solar irradiation
affecting the nuclear decay rates. We then provide the result of four half-life
measurements we performed underground at LNGS in the period from May 2014 to
January 2015 with radon diffused into olive oil. Briefly, we did not measure
any change of the 222Rn half-life with a 8*10^-5 precision. Finally, we provide
the most precise value for the 222Rn half-life: 3.82146(16){stat}(4){syst}
days.Comment: Accepted for publication in Physics Letters B, 6 pages, 6 figure
Search for correlations between solar flares and decay rate of radioactive nuclei
The deacay rate of three different radioactive sources 40K, 137Cs and natTh
has been measured with NaI and Ge detectors. Data have been analyzed to search
for possible variations in coincidence with the two strongest solar flares of
the years 2011 and 2012. No significant deviations from standard expectation
have been observed, with a few 10-4 sensitivity. As a consequence, we could not
find any effect like that recently reported by Jenkins and Fischbach: a few per
mil decrease in the decay rate of 54Mn during solar flares in December 2006.Comment: 5 pages, 3 figure
Phase structure of a generalized Nambu Jona-Lasinio model with Wilson fermions in the mean field or large -expansion
We analyze the vacuum structure of a generalized lattice Nambu--Jona-Lasinio
model with two flavors of Wilson fermions, such that its continuum action is
the most general four-fermion action with 'trivial' color interactions, and
having a symmetry in the chiral limit. The phase structure
of this model in the space of the two four-fermion couplings shows, in addition
to the standard Aoki phases, new phases with , in
close analogy to similar results recently suggested by some of us for lattice
QCD with two degenerate Wilson fermions. This result shows how the phase
structure of an effective model for low energy QCD cannot be entirely
understood from Wilson Chiral Perturbation Theory, based on the standard QCD
chiral effective Lagrangian approach.Comment: 24 pages, 3 figures, sent to Nuclear Physics
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