CMOS-3D smart imager architectures for feature detection

This paper reports a multi-layered smart image sensor architecture for feature extraction based on detection of interest points. The architecture is conceived for 3-D integrated circuit technologies consisting of two layers (tiers) plus memory. The top tier includes sensing and processing circuitry aimed to perform Gaussian filtering and generate Gaussian pyramids in fully concurrent way. The circuitry in this tier operates in mixed-signal domain. It embeds in-pixel correlated double sampling, a switched-capacitor network for Gaussian pyramid generation, analog memories and a comparator for in-pixel analog-to-digital conversion. This tier can be further split into two for improved resolution; one containing the sensors and another containing a capacitor per sensor plus the mixed-signal processing circuitry. Regarding the bottom tier, it embeds digital circuitry entitled for the calculation of Harris, Hessian, and difference-of-Gaussian detectors. The overall system can hence be configured by the user to detect interest points by using the algorithm out of these three better suited to practical applications. The paper describes the different kind of algorithms featured and the circuitry employed at top and bottom tiers. The Gaussian pyramid is implemented with a switched-capacitor network in less than 50 μs, outperforming more conventional solutions.Xunta de Galicia 10PXIB206037PRMinisterio de Ciencia e Innovación TEC2009-12686, IPT-2011-1625-430000Office of Naval Research N00014111031

Titanium alloy microstructure fingerprint plots from in-process machining

Titanium alloy components require several machining stages of forged billets which are supplied in a range of annealing conditions. Generally, the machining performance is influenced by the heat treatment and changes in billet microstructures are often overlooked by tool manufacturers and machinists. Due to the non-linear strain path during primary forging, titanium alloy billets are anisotropic in nature and require ex-situ non-destructive evaluation (NDE) during the manufacturing stages to ensure excellent service performance, particularly in safety-critical aerospace components. In this study, the local analysis of the fluctuations presented in the force response during face-turning operations is directly linked to the billet heat treatment condition and presented as microstructure fingerprint plots. The evolution of cutting forces in four different billet conditions of the alpha + beta titanium alloy Ti–6Al–2Sn–4Zr–6Mo (Ti-6246) was measured. The magnitude and fluctuations in force were directly correlated to microstructural features derived from the heat treatments. In addition, local spatial high-resolution synchronization of the cutting forces was used to determine the effects of microstructure from the heterogeneous upstream forging process and subsequent heat treatment. These rapidly produced microstructure fingerprint plots are an important development step for providing manufacturers with an in-process machining NDE method: this will help to qualify material upstream prior to expensive secondary forging or finish machining stages

Super-resolution far-field ghost imaging via compressive sampling

Much more image details can be resolved by improving the system's imaging resolution and enhancing the resolution beyond the system's Rayleigh diffraction limit is generally called super-resolution. By combining the sparse prior property of images with the ghost imaging method, we demonstrated experimentally that super-resolution imaging can be nonlocally achieved in the far field even without looking at the object. Physical explanation of super-resolution ghost imaging via compressive sampling and its potential applications are also discussed.Comment: 4pages,4figure

Autopsie d’une membrane d’osmose inverse usagée prélevée dans le Parc National du Banc d’Arguin (PNBA) en Mauritanie : cas d’étude de Teichitt

L’objectif de ce travail est d’étudier l’état de vieillissement d’une membrane d’osmose inverse (OI) usagée prélevée en Mauritanie sur une unité de dessalement installée par la coopération canarienne à Teichitt dans le parc national du banc d’Arguin et de lui appliquer une démarche d’autopsie. L’usure de la membrane est caractérisée par une augmentation significative de la perméabilité hydraulique (25 % d’augmentation) et une diminution de la rétention en sels (10 % à 30 % de diminution). Un modèle de transfert de matière de type diffusion-convection permet de montrer l’augmentation du caractère convectif du transfert, lorsque la pression transmembranaire augmente et en particulier au-delà de 15 bars. Ainsi, l’usure de la membrane d’OI induit son rapprochement vers un transfert de matière combiné de solubilisation-diffusion/convection, typique d’une opération de nanofiltration (NF). L’analyse topographique par AFM de la surface de la membrane usagée en comparaison de la membrane neuve laisse apparaître des « cavités » à plusieurs endroits de la surface usagée traduisant la dégradation physique de celle-ci. De plus, la rugosité de surface de la membrane usagée avec 74 nm est apparue supérieure à celle de la membrane neuve avec 54 nm, ce qui nous informe de la présence de matières colmatantes, dont la nature reste encore à déterminer. Par contre, l’étude de la dégradation chimique des membranes usagées et neuves par la détermination de leur point isoélectrique (PIE) à partir d’une mesure de potentiel d’écoulement transmembranaire ne montre pas de modifications significatives de ce paramètre (PIE = 2,5), preuve de la non-dégradation chimique interne de la membrane. Enfin, les résultats d’une étude statistique préliminaire sont présentés. Celle-ci consiste à évaluer l’hétérogénéité de l’usure en matière de perméabilité hydraulique et de rétention d’une solution de NaCl 0,1 M à 15 bars et 19 °C, pour six coupons différents pris sur les trois feuilles de membranes constituant le module d’osmose inverse usagé. Une tendance se dégage, elle montre en particulier que l’usure est hétérogène, non seulement au sein d’une même feuille de membrane, mais aussi au sein des différentes membranes constituant le module. En résumé, il est observé pour la première fois qu’une vieille membrane d’OI employée pendant deux années pour le dessalement d’eau de mer, dans les conditions d’utilisation sahariennes en Mauritanie (sans pré-traitements), acquiert une microporosité qui lui confère les propriétés d’une membrane de nanofiltration.Currently used reverse osmosis (RO) membranes from desalination units are burned at the end of their life as membranes for seawater desalination. In the future, a possible alternative would be to reuse the old RO membranes as nanofiltration (NF), ultrafiltration (UF) or microfiltration (MF) membranes, i.e. for wastewater treatments, but before reuse, the level of RO membrane degradation must be evaluated by autopsy studies.Our goal in the present study was to demonstrate for the first time that a used RO membrane could be used for nanofiltration. The used RO membrane was purchased from a desalination bench scale unit based in the town of Teichitt (in north-west Nouakchott, Mauritania). Membrane autopsy studies showed an increase in its hydraulic permeability (25%) and a concurrent decrease in its salt rejection behaviour (10% to 30%). We also studied the modification of mass transfer before and after ageing, and demonstrated the onset of a convective component in the mass transfer of salts and an increase in membrane hydraulic permeability. Furthermore, the determination of the isoelectric point (IEP) of the membrane, using streaming potential measurements across the membranes, showed no change in IEP, with a value of 2.5 ± 0.2 . A preliminary study, based on a statistical evaluation of membrane degradation from hydraulic permeability and salt rejection experiments, showed heterogeneous wear of the membrane (most important in the centre). Finally, we observed for the first time that after two years of use for desalination, a used RO membrane had acquired a microporosity that corresponded to the properties of a new NF membrane

Likelihood analysis of the pMSSM11 in light of LHC 13-TeV data

We use MasterCode to perform a frequentist analysis of the constraints on a phenomenological MSSM model with 11 parameters, the pMSSM11, including constraints from ∼36 /fb of LHC data at 13 TeV and PICO, XENON1T and PandaX-II searches for dark matter scattering, as well as previous accelerator and astrophysical measurements, presenting fits both with and without the (g−2)μ constraint. The pMSSM11 is specified by the following parameters: 3 gaugino masses M1,2,3 , a common mass for the first-and second-generation squarks mq~ and a distinct third-generation squark mass mq~3 , a common mass for the first-and second-generation sleptons mℓ~ and a distinct third-generation slepton mass mτ~ , a common trilinear mixing parameter A, the Higgs mixing parameter μ , the pseudoscalar Higgs mass MA and tanβ . In the fit including (g−2)μ , a Bino-like χ~01 is preferred, whereas a Higgsino-like χ~01 is mildly favoured when the (g−2)μ constraint is dropped. We identify the mechanisms that operate in different regions of the pMSSM11 parameter space to bring the relic density of the lightest neutralino, χ~01 , into the range indicated by cosmological data. In the fit including (g−2)μ , coannihilations with χ~02 and the Wino-like χ~±1 or with nearly-degenerate first- and second-generation sleptons are active, whereas coannihilations with the χ~02 and the Higgsino-like χ~±1 or with first- and second-generation squarks may be important when the (g−2)μ constraint is dropped. In the two cases, we present χ2 functions in two-dimensional mass planes as well as their one-dimensional profile projections and best-fit spectra. Prospects remain for discovering strongly-interacting sparticles at the LHC, in both the scenarios with and without the (g−2)μ constraint, as well as for discovering electroweakly-interacting sparticles at a future linear e+e− collider such as the ILC or CLIC

A new multicompartmental reaction-diffusion modeling method links transient membrane attachment of E. coli MinE to E-ring formation

Many important cellular processes are regulated by reaction-diffusion (RD) of molecules that takes place both in the cytoplasm and on the membrane. To model and analyze such multicompartmental processes, we developed a lattice-based Monte Carlo method, Spatiocyte that supports RD in volume and surface compartments at single molecule resolution. Stochasticity in RD and the excluded volume effect brought by intracellular molecular crowding, both of which can significantly affect RD and thus, cellular processes, are also supported. We verified the method by comparing simulation results of diffusion, irreversible and reversible reactions with the predicted analytical and best available numerical solutions. Moreover, to directly compare the localization patterns of molecules in fluorescence microscopy images with simulation, we devised a visualization method that mimics the microphotography process by showing the trajectory of simulated molecules averaged according to the camera exposure time. In the rod-shaped bacterium _Escherichia coli_, the division site is suppressed at the cell poles by periodic pole-to-pole oscillations of the Min proteins (MinC, MinD and MinE) arising from carefully orchestrated RD in both cytoplasm and membrane compartments. Using Spatiocyte we could model and reproduce the _in vivo_ MinDE localization dynamics by accounting for the established properties of MinE. Our results suggest that the MinE ring, which is essential in preventing polar septation, is largely composed of MinE that is transiently attached to the membrane independently after recruited by MinD. Overall, Spatiocyte allows simulation and visualization of complex spatial and reaction-diffusion mediated cellular processes in volumes and surfaces. As we showed, it can potentially provide mechanistic insights otherwise difficult to obtain experimentally

Site Fidelity in Space Use by Spider Monkeys (Ateles geoffroyi) in the Yucatan Peninsula, Mexico

Animal home ranges may vary little in their size and location in the short term but nevertheless show more variability in the long term. We evaluated the degree of site fidelity of two groups of spider monkeys (Ateles geoffroyi) over a 10- and 13-year period, respectively, in the northeastern Yucatan peninsula, Mexico. We used the Local Convex Hull method to estimate yearly home ranges and core areas (defined as the 60% probability contour) for the two groups. Home ranges varied from 7.7 to 49.6 ha and core areas varied from 3.1 to 9.2 ha. We evaluated the degree of site fidelity by quantifying the number of years in which different areas were used as either home ranges or core areas. Large tracts were used only as home ranges and only for a few years, whereas small areas were used as either core area or home range for the duration of the study. The sum of the yearly core areas coincided partially with the yearly home ranges, indicating that home ranges contain areas used intermittently. Home ranges, and especially core areas, contained a higher proportion of mature forest than the larger study site as a whole. Across years and only in one group, the size of core areas was positively correlated with the proportion of adult males in the group, while the size of home ranges was positively correlated with both the proportion of males and the number of tree species included in the diet. Our findings suggest that spider monkey home ranges are the result of a combination of long-term site fidelity and year-to-year use variation to enable exploration of new resources

Colombia's cyberinfrastructure for biodiversity: Building data infrastructure in emerging countries to foster socioeconomic growth

Science and innovation are not a luxury but a prerequisite for social and economic development (Annan, 2003)

VAMOS: a Pathfinder for the HAWC Gamma-Ray Observatory

VAMOS was a prototype detector built in 2011 at an altitude of 4100m a.s.l. in the state of Puebla, Mexico. The aim of VAMOS was to finalize the design, construction techniques and data acquisition system of the HAWC observatory. HAWC is an air-shower array currently under construction at the same site of VAMOS with the purpose to study the TeV sky. The VAMOS setup included six water Cherenkov detectors and two different data acquisition systems. It was in operation between October 2011 and May 2012 with an average live time of 30%. Besides the scientific verification purposes, the eight months of data were used to obtain the results presented in this paper: the detector response to the Forbush decrease of March 2012, and the analysis of possible emission, at energies above 30 GeV, for long gamma-ray bursts GRB111016B and GRB120328B.Comment: Accepted for pubblication in Astroparticle Physics Journal (20 pages, 10 figures). Corresponding authors: A.Marinelli and D.Zaboro