Wireless Cloud Architecture Based on Thin Clients and Ontologies

Recently, several researchers have discovered the need for radios to use description techniques for the objects in the wireless realm. The concept of RF field-programmable analog array (FPAA) was also proposed recently and the lack of hardware abstractions was identified as a problem. We propose a hardware abstraction for RF FPAAs, which enables an open RF-digital interface. We advance the concept of wireless thin clients. These clients are connected to the cloud using the open RF-digital interface. We describe the architecture of a comprehensive wireless ontology

Tracing the general structure of Galactic molecular clouds using Planck data: I. The Perseus region as a test case

We present an analysis of probability distribution functions (pdfs) of column density in different zones of the star-forming region Perseus and its diffuse environment based on the map of dust opacity at 353 GHz available from the Planck archive. The pdf shape can be fitted by a combination of a lognormal function and an extended power-law tail at high densities, in zones centred at the molecular cloud Perseus. A linear combination of several lognormals fits very well the pdf in rings surrounding the cloud or in zones of its diffuse neighbourhood. The slope of the mean density scaling law $\langle\rho\rangle_L \propto L^\alpha$ is steep ($\alpha=-1.93$) in the former case and rather shallow ($\alpha=-0.77\pm0.11$) in the rings delineated around the cloud. We interpret these findings as signatures of two distinct physical regimes: i) a gravoturbulent one which is characterized by nearly linear scaling of mass and practical lack of velocity scaling; and ii) a predominantly turbulent one which is best described by steep velocity scaling and by invariant for compressible turbulence $\langle\rho\rangle_L u_L^3/L$, describing a scale-independent flux of the kinetic energy per unit volume through turbulent cascade. The gravoturbulent spatial domain can be identified with the molecular cloud Perseus while a relatively sharp transition to predominantly turbulent regime occurs in its vicinity.Comment: Accepted for publication in MNRAS; 16 pages with Appendix, 15 figure

Radiation Tolerance and Charge Trapping Enhancement of ALD HfO2/Al2O3 Nanolaminated Dielectrics

High-k dielectric stacks are regarded as a promising information storage media in the Charge Trapping Non-Volatile Memories, which are the most viable alternative to the standard floating gate memory technology. The implementation of high-k materials in real devices requires (among the other investigations) estimation of their radiation hardness. Here we report the effect of gamma radiation (60Co source, doses of 10 and 10 kGy) on dielectric properties, memory windows, leakage currents and retention characteristics of nanolaminated HfO2/Al2O3 stacks obtained by atomic layer deposition and its relationship with post-deposition annealing in oxygen and nitrogen ambient. The results reveal that depending on the dose, either increase or reduction of all kinds of electrically active defects (i.e., initial oxide charge, fast and slow interface states) can be observed. Radiation generates oxide charges with a different sign in O2 and N2 annealed stacks. The results clearly demonstrate a substantial increase in memory windows of the as-grown and oxygen treated stacks resulting from enhancement of the electron trapping. The leakage currents and the retention times of O2 annealed stacks are not deteriorated by irradiation, hence these stacks have high radiation tolerance

Etude d'un système de refroidissement basé sur l'utilisation d'une pompe électro-osmotique

National audiencele refroidissement de l'électronique de puissance se caractérise souvent par de très hautes densités de flux de chaleur à évacuer. Il est donc nécessaire d'utiliser des solutions d'extraction de la chaleur adaptées : convection forcée liquide, caloducs, boucles à pompage capillaire... Dans le cas du refroidissement par convection forcée, un des points sensibles est la pompe. Nous proposons dans cet article d'étudier la possibilité de remplacer la pompes mécanique classique par une pompe électro-osmotique. Une pompe basée sur l'utilisation d'un milieu poreux en céramique parait bien adaptée pour cette application. Après avoir fait quelques rappels sur le pompage par électroosmose, nous présentons et testons un prototype fonctionnant en tension alternative qui est ensuite introduit dans un système de refroidissemen

Spatially associated clump populations in Rosette from CO and dust maps

Spatial association of clumps from different tracers turns out to be a valuable tool to determine the physical properties of molecular clouds. It provides a reliable estimate for the X-factors, serves to trace the density of clumps seen in column densities only, and allows one to measure the velocity dispersion of clumps identified in dust emission. We study the spatial association between clump populations, extracted by use of the GAUSSCLUMPS technique from (CO)-C-12(1-0), (CO)-C-13(1-0) line maps and Herschel dust-emission maps of the star-forming region Rosette, and analyse their physical properties. All CO clumps that overlap with another CO or dust counterpart are found to be gravitationally bound and located in the massive star-forming filaments of the molecular cloud. They obey a single mass-size relation M-cl proportional to R-cl(gamma) with gamma similar or equal to 3 (implying constant mean density) and display virtually no velocity-size relation. We interpret their population as low-density structures formed through compression by converging flows and still not evolved under the influence of self-gravity. The high-mass parts of their clump mass functions are fitted by a power law dN(cl)/d log M-cl proportional to M-cl(Gamma) cl and display a nearly Salpeter slope Gamma similar to -1.3. On the other hand, clumps extracted from the dust-emission map exhibit a shallower mass-size relation with gamma = 2.5 and mass functions with very steep slopes Gamma similar to -2.3 even if associated with CO clumps. They trace density peaks of the associated CO clumps at scales of a few tenths of pc where no single density scaling law should be expected

Charge Storage and Reliability Characteristics of Nonvolatile Memory Capacitors with HfO2/Al2O3-Based Charge Trapping Layers

Flash memories are the preferred choice for data storage in portable gadgets. The charge trapping nonvolatile flash memories are the main contender to replace standard floating gate technology. In this work, we investigate metal/blocking oxide/high-k charge trapping layer/tunnel oxide/Si (MOHOS) structures from the viewpoint of their application as memory cells in charge trapping flash memories. Two different stacks, HfO2/Al2O3 nanolaminates and Al-doped HfO2, are used as the charge trapping layer, and SiO2 (of different thickness) or Al2O3 is used as the tunneling oxide. The charge trapping and memory windows, and retention and endurance characteristics are studied to assess the charge storage ability of memory cells. The influence of post-deposition oxygen annealing on the memory characteristics is also studied. The results reveal that these characteristics are most strongly affected by post-deposition oxygen annealing and the type and thickness of tunneling oxide. The stacks before annealing and the 3.5 nm SiO2 tunneling oxide have favorable charge trapping and retention properties, but their endurance is compromised because of the high electric field vulnerability. Rapid thermal annealing (RTA) in O2 significantly increases the electron trapping (hence, the memory window) in the stacks; however, it deteriorates their retention properties, most likely due to the interfacial reaction between the tunneling oxide and the charge trapping layer. The O2 annealing also enhances the high electric field susceptibility of the stacks, which results in better endurance. The results strongly imply that the origin of electron and hole traps is different—the hole traps are most likely related to HfO2, while electron traps are related to Al2O3. These findings could serve as a useful guide for further optimization of MOHOS structures as memory cells in NVM

On the extraction of the power-law parts of probability density functions in star-forming clouds

We present a new approach to extract the power-law part of a density/column-density probability density function (.-pdf/N-pdf) in star-forming clouds. This approach is based on the mathematical method BPLFIT of Virkar & Clauset (2014, Annals of Applied Statistics, 8, 89) and it assesses the power-law part of an arbitrary distribution, without any assumptions about the other parts of this distribution. The slope and deviation point are derived as averaged values as the number of bins is varied. Neither parameter is sensitive to spikes and other local features of the tail. This adapted BPLFIT method is applied to two different sets of data from numerical simulations of star-forming clouds at scales 0.5 and 500 pc, and it displays.-pdf and N-pdf evolution in agreement with a number of numerical and theoretical studies. Applied to Herschel data on the regions Aquila and Rosette, the method extracts pronounced power-law tails, consistent with those seen in simulations of evolved clouds