The implementation methodology of the real effects in a NOI nanostructure,aided by simulation and modelling

The SOI transistors permanently offer new candidates as nanodevices. The nothing on insulator NOI transistor was recently derived from the nano SOI–MOSFET family. Their output characteristics were theoretical modelled with an exponential law, validated by simulations. The transfer characteristics presented sometimes increasing and others times decreasing monotony. This phenomenon was put directly into a relationship with the gate tunnelling breakdown. This paper has three final targets: the breakdown limitation through the back-gate terminal, the real effects including in the NOI transistor architecture – like interface charges or metal-semiconductor work function and quantum effects corrections in simulations, in order to produce a better correlation between simulations and a real behaviour. These simulations represent a milestone in the NOI nanotransistor manufacturing, establishing some parameters that link the device to the real work regime.     

Determination of the refractive index and thickness of holographic silver halide materials by use of polarized reflectances

A method to determine the refractive index and thickness of silver halide emulsions used in holography is presented. The emulsions are in the form of a layer of film deposited on a thick glass plate. The experimental reflectances of p-polarized light are measured as a function of the incident angles, and the values of refractive index, thickness, and extinction coefficient of the emulsion are obtained by using the theoretical equation for reflectance. As examples, five commercial holographic silver halide emulsions are analyzed. The procedure to obtain the measurements and the numerical analysis of the experimental data are simple, and agreement of the calculated reflectances, by use of the thickness and refractive index obtained, with the measured reflectances is satisfactory.     

Useful network transformations and reconfigurable analogue filters using the complementary transformation

In this paper it is shown that some of the useful network transformations, such as low pass (LP) to band pass (BP), LP to high pass (HP) and HP to BP can be obtained by means of the complementary transformation (CT). Furthermore, because the CT is a topological one (i.e. the component values remain unchanged, but their position within the circuit changes), it is suitable to realize reconfigurable analogue filter arrays. As an example, a full list of the obtainable GIC‐based filters, along with their design equations, is also presented. Copyright © 2001 John Wiley & Sons, Ltd.     

DualMiner: A Dual-Pruning Algorithm for Itemsets with Constraints

Recently, constraint-based mining of itemsets for questions like find all frequent itemsets whose total price is at least $50 has attracted much attention. Two classes of constraints, monotone and antimonotone, have been very useful in this area. There exist algorithms that efficiently take advantage of either one of these two classes, but no previous algorithms can efficiently handle both types of constraints simultaneously. In this paper, we present DualMiner, the first algorithm that efficiently prunes its search space using both monotone and antimonotone constraints. We complement a theoretical analysis and proof of correctness of DualMiner with an experimental study that shows the efficacy of DualMiner compared to previous work.     

Motility,mixing, and multicellularity

A fundamental issue in evolutionary biology is the transition from unicellular to multicellular organisms, and the cellular differentiation that accompanies the increase in group size. Here we consider recent results on two types of “multicellular” systems, one produced by many unicellular organisms acting collectively, and another that is permanently multicellular. The former system is represented by groups of the bacterium Bacillus subtilis and the latter is represented by members of the colonial volvocalean green algae. In these flagellated organisms, the biology of chemotaxis, metabolism and cell–cell signaling is intimately connected to the physics of buoyancy, motility, diffusion, and mixing. Our results include the discovery in bacterial suspensions of intermittent episodes of disorder and collective coherence characterized by transient, recurring vortex streets and high-speed jets of cooperative swimming. These flow structures markedly enhance transport of passive tracers, and therefore likely have significant implications for intercellular communication. Experiments on the Volvocales reveal that the sterile flagellated somatic cells arrayed on the surface of Volvox colonies are not only important for allowing motion toward light (phototaxis), but also play a crucial role in driving fluid flows that transport dissolved molecular species. These flows, generated by the collective beating of flagella, confer a synergistic advantage with regard to transport of nutrients and chemical messengers. They allow these species to circumvent a nutrient acquisition bottleneck which would exist if transport were purely diffusive, and thereby evolve to larger multicellular individuals. In both cases, a higher level of organization, specialization and complexity counteract the higher costs inherent to larger groups.     

Robust optimal experiment design for system identification

This paper develops the idea of min-max robust experiment design for dynamic system identification. The idea of min-max experiment design has been explored in the statistics literature. However, the technique is virtually unknown by the engineering community and, accordingly, there has been little prior work on examining its properties when applied to dynamic system identification. This paper initiates an exploration of these ideas. The paper considers linear systems with energy (or power) bounded inputs. We assume that the parameters lie in a given compact set and optimise the worst case over this set. We also provide a detailed analysis of the solution for an illustrative one parameter example and propose a convex optimisation algorithm that can be applied more generally to a discretised approximation to the design problem. We also examine the role played by different design criteria and present a simulation example illustrating the merits of the proposed approach.     

The use of remote-sensing techniques to monitor dense reservoir networks in the Brazilian semiarid region

Reservoirs are the main water source in the Brazilian semiarid region, especially in the crystalline-geology watersheds, forming high-density reservoir networks (HdRN). However, in most cases, the construction of these reservoirs has been done without technical supervision. The objective of this work was to map and evaluate the spatial distribution of the 25,000 km² Orós Reservoir Basin (ORB) HdRN, in semiarid Brazil, with the help of remote-sensing tools associated with geographic information systems (GIS). Using LANDSAT 5 images of the end of the 2011 rainy season of the ORB, the remote-sensing technique allowed the identification of 6002 polygons, which corresponded to only 4717 reservoirs (implying a misidentification of 21%). Between 2002 and 2011, a 17.5% increase (and 1.81% annual increase) in the number of reservoirs in the basin was observed, still lower than the annual increment from 1970 to 2002, when an average increase of 2.64% per year was observed, in other studies. The perimeter of the reservoirs ranged from 0.250 to 560 km and the individual water surface area ranged from 0.004 to 195.0 km², resulting in a total surface of 465.0 km². Analysing the surface area of the strategic reservoirs, results showed that the estimation of the surface area (from remote sensing with manual polygon adjustment) yielded values very close to those of the on-site monitored areas, with R² = 0.99 and normalized difference index ranging from ?0.02 to +0.09. The reservoir density in the ORB in 2011 was 0.19 reservoirs km^–2, higher than the recommended optimum density of 0.15 reservoirs km^–2 basin. Analysis of reservoir density by municipality recorded values ranging from 0.02 to 0.40 reservoirs km^–2. The sedimentary-geology municipalities presented a reservoir density on average 80% lower than the that of the crystalline-geology municipalities, indicating a strong relationship between geology and reservoir density. Neither population density nor rainfall explained the spatial distribution of reservoirs within the basin, both yielding R² lower than 0.1. This remote-sensing survey of reservoirs demonstrated two major flaws: the misidentification of shadows as reservoirs and the inability to identify the presence of macrophytes, which negatively affected the number and surface area of the target reservoirs. Despite these problems, remote sensing has been shown to be a technique of great potential in the planning and management of water resources in regions with dense reservoir networks.     

Synthesis and Theoretical Study of New Guanylated Cyclophosphazenes and Their Use in the CO2 Fixation into Styrene Carbonate

Three new guanylated cyclophosphazenes G1–G3 have been synthesized through the catalytic guanylation of three different bi, tetra and hexa (p-aminophenoxy)-cyclophosphazenes by using N,N’-diisopropylcarbodiimide as guanylating agent, ZnEt₂ as catalyst and dry tetrahydrofuran as solvent. The resulting products have been characterized by ¹H, ¹³C{¹H} and ³¹P{¹H} NMR spectroscopy. The hexaguanylated cyclophosphazenes exhibit a deep purple colour, unusual for this type of compounds. The electronic structure of these compounds was investigated by carrying out density functional calculations at PBE-D3(BJ)/TZP level of theory. The molecular structural analysis reveals that aromatic rings are stacked and time dependent density functional calculations show that a charge transfer electronic transition occurs between the aromatic rings which absorb light around 500–700 nm. Finally, the catalytic usefulness of guanylated cyclophosphazene compounds G1–G3 has been proven by the preparation of styrene carbonate from the reaction between styrene oxide and carbon dioxide.

     

Incremental model-based estimation using geometric constraints

We present a model-based framework for incremental, adaptive object shape estimation and tracking in monocular image sequences. Parametric structure and motion estimation methods usually assume a fixed class of shape representation (splines, deformable superquadrics, etc.) that is initialized prior to tracking. Since the model shape coverage is fixed a priori, the incremental recovery of structure is decoupled from tracking, thereby limiting both processes in their scope and robustness. In this work, we describe a model-based framework that supports the automatic detection and integration of low-level geometric primitives (lines) incrementally. Such primitives are not explicitly captured in the initial model, but are moving consistently with its image motion. The consistency tests used to identify new structure are based on trinocular constraints between geometric primitives. The method allows not only an increase in the model scope, but also improves tracking accuracy by including the newly recovered features in its state estimation. The formulation is a step toward automatic model building, since it allows both weaker assumptions on the availability of a prior shape representation and on the number of features that would otherwise be necessary for entirely bottom-up reconstruction. We demonstrate the proposed approach on two separate image-based tracking domains, each involving complex 3D object structure and motion.