Surface Segregation Mechanisms in Ferroelectric Thin Films

Reliability issues have hampered the adoption of ferroelectric thin films by the microelectronics industry. One of these is imprint, an important problem affecting the performance of ferroelectric non-volatile memories. This paper presents the effects of the low temperature pyrolysis step on the chemical and physical properties of SrBi₂Ta₂O₉ films. A comparison of the hysteretic properties and composition profiles shows that control of the oxidising conditions during pyrolysis is critical to the dielectric properties. Data from this work and from the literature have been used to construct a model that explains the origin of surface depletion and segregation, self poling and as-grown imprint in ferroelectric films.     

Protective nature of nano-TiN coatings shaped by EPD on Ti substrates

The hardness and corrosion resistance of TiN coatings, processed by Electrophoretic Deposition (EPD) to cover polished and unpolished Ti substrates, have been evaluated. A deposition time of 5 min has been enough to obtain a cohesive layer of 7–8 μm in thickness. The coatings were thermally treated in vacuum atmosphere at 1200 °C for 1 h with heating and cooling rates of 5 °C min^?1. The surfaces have been covered homogeneously optimizing the properties of the Ti substrates. Uniform and dense TiN coatings have been obtained onto polished substrates, while on unpolished Ti the nitrogen diffuses toward the substrate, moderately dissolving TiN coating. The nanohardness values of the polished samples have been increased from 2.8–4.8 GPa up to 6.5–8.5 GPa. Besides, the corrosion current density has been reduced more than one order of magnitude obtaining a protective efficiency of 82%. These values have been compared with other works in literature where authors used complex and costly processing techniques, demonstrating the strong impact of the colloidal processing over the specific properties of the material.     

Intrinsic Fluorescence of the Active and the Inactive Functional Forms of Human Thymidylate Synthase

The observables associated with protein intrinsic fluorescence – spectra, time decays, anisotropies – offer opportunities to monitor in real time and non-invasively a protein‘s functional form and its interchange with other forms with different functions. We employed these observables to sketch the fluorometric profiles of two functional forms of human thymidylate synthase (hTS), a homodimeric enzyme crucial for cell proliferation and thus targeted by anticancer drugs. The protein takes an active and an inactive form. Stabilization of the latter by peptides that, unlike classical hTS inhibitors, bind it at the monomer/monomer interface offers an alternative inhibition mechanism that promises to avoid the onset of drug resistance in anticancer therapy. The fluorescence features depicted herein can be used as tools to identify and quantify each of the two protein forms in solution, thus making it possible to investigate the kinetic and thermodynamic aspects of the active/inactive conformational interchange. Two examples of fluorometrically monitored interconversion kinetics are provided.     

MPGS: an interactive tool for the specification and generation ofmultimedia presentations

Multimedia presentations are composed of objects belonging to different data types such as video, audio, text and image. An important aspect is that, quite often, the user defining a presentation needs to express sophisticated temporal and spatial constraints among the objects composing the presentation. We present a system (called MPGS-Multimedia Presentation Generator System) which supports the specification of constraints among multimedia objects and the generation of multimedia presentations according to the specified constraints. The constraint model provided by MPGS is very flexible and powerful in terms of the kinds of object constraints it can represent. A large number of innovative features are supported including: asynchronous and simultaneous spatial constraints; components of interest and priority levels; motion functions. Obviously, the flexibility provided to the users requires the development of nontrivial techniques to check constraint consistency and to generate a presentation satisfying the specified constraints. We illustrate the solutions we have devised in the framework of MPGS     

SusyMath: A Mathematica package for quantum superfield calculations

SusyMath is a Mathematica package for quantum superfield calculations. It defines a standard form to translate the correction to the effective action corresponding to a given supergraph into a Mathematica expression, which is then evaluated and simplified. Several functions for manipulations of these expressions are provided, and the package also has the ability to save the outcomes of its calculations in form.

Program summary

Title of program: SusyMathCatalogue identifier:ADYQ_v1_0Program summary URL:http://cpc.cs.qub.ac.uk/summaries/ADYQ_v1_0Program obtainable from: CPC Program Library, Queen's University of Belfast, N. Ireland, also at http://fma.if.usp.br/~alysson/SusyMathLicensing provisions: LGPL, CPC non-profit use licenseProgramming language: MathematicaPlatform: Any platform supporting Mathematica 4.0 or higherComputer tested on: PC (Athlon64 X2 +3800); 1 GB RAMOperating system under which the program has been tested: Linux (Debian 4.0); XOrg 7.0.22; Mathematica 5.2No. of lines in distributed program, including test data, etc.:42 472No. of bytes in distributed program, including test data, etc.:471 596Distribution format:tar.gzNature of the problem: Evaluate quantum corrections to the effective action of supersymmetric field theories, formulated in the superfield formalism, both in three- and four-spacetime dimensions.Solution method: A set of procedures for integration by parts, application of the algebra of covariant derivatives and Grassman integration, along with several auxiliary functions, is introduced.Restrictions: At the moment, the background field method is not implemented, but the system is designed to be further generalized.Running time: Depends on the complexity of the problem. From seconds for simpler one-loop diagrams to several hours for simple two-loop graphs.     

From Images to Shape Models for Object Detection

We present an object class detection approach which fully integrates the complementary strengths offered by shape matchers. Like an object detector, it can learn class models directly from images, and can localize novel instances in the presence of intra-class variations, clutter, and scale changes. Like a shape matcher, it finds the boundaries of objects, rather than just their bounding-boxes. This is achieved by a novel technique for learning a shape model of an object class given images of example instances. Furthermore, we also integrate Hough-style voting with a non-rigid point matching algorithm to localize the model in cluttered images. As demonstrated by an extensive evaluation, our method can localize object boundaries accurately and does not need segmented examples for training (only bounding-boxes).     

Identifying and understanding urban sport areas using Nokia Sports Tracker

Current advancements in pervasive technologies allow users to create and share an increasing amount of whereabouts data. Thus, some rich datasets on human mobility are becoming available on the web. In this paper we extracted approximately 790,000 mobility traces from a web-based repository of GPS tracks—the Nokia Sports Tracker Service. Using data mining mechanisms, we show that this data can be analyzed to uncover daily routines and interesting schemes in the use of public spaces. We first show that our approach supports large-scale analysis of people’s whereabouts by comparing behavioral patterns across cities. Then, using Kernel Density Estimation, we present a mechanism to identify popular sport areas in individual cities. This kind of analysis allows us to highlight human-centered geographies that can support a wide range of applications ranging from location-based services to urban planning.     

A low-cost real time virtual system for postural stability assessment at home

Background and objective

The degeneration of the balance control system in the elderly and in many pathologies requires measuring the equilibrium conditions very often. In clinical practice, equilibrium control is commonly evaluated by using a force platform (stabilometric platform) in a clinical environment.In this paper, we demonstrate how a simple movement analysis system, based on a 3D video camera and a 3D real time model reconstruction of the human body, can be used to collect information usually recorded by a physical stabilometric platform.

Methods

The algorithm used to reconstruct the human body model as a set of spheres is described and discussed. Moreover, experimental measurements and comparisons with data collected by a physical stabilometric platform are also reported. The measurements were collected on a set of 6 healthy subjects to whom a change in equilibrium condition was stimulated by performing an equilibrium task.

Results

The experimental results showed that more than 95% of data collected by the proposed method were not significantly different from those collected by the classic platform, thus confirming the usefulness of the proposed system.

Conclusions

The proposed virtual balance assessment system can be implemented at low cost (about 500$) and, for this reason, can be considered a home use medical device. On the contrary, astabilometric platform has a cost of about 10,000$ and requires periodical calibration. The proposed system does not require periodical calibration, as is necessary for stabilometric force platforms, and it is easy to use. In future, the proposed system with little integration can be used, besides being an emulator of a stabilometric platform, also to recognize and track, in real time, head, legs, arms and trunk, that is to collect information actually obtained by sophisticated optoelectronic systems.