Novel alginate based nanocomposite hydrogels with incorporated silver nanoparticles

Alginate colloid solution containing electrochemically synthesized silver nanoparticles (AgNPs) was investigated regarding the nanoparticle stabilization and possibilities for production of alginate based nanocomposite hydrogels in different forms. AgNPs were shown to continue to grow in alginate solutions for additional 3 days after the synthesis by aggregative mechanism and Ostwald ripening. Thereafter, the colloid solution remains stable for 30 days and could be used alone or in mixtures with aqueous solutions of poly(vinyl alcohol) (PVA) and poly(N-vinyl-2-pyrrolidone) (PVP) while preserving AgNPs as verified by UV–Vis spectroscopy studies. We have optimized techniques for production of Ag/alginate microbeads and Ag/alginate/PVA beads, which were shown to efficiently release AgNPs decreasing the Escherichia coli concentration in suspensions for 99.9% over 24 h. Furthermore, Ag/hydrogel discs based on alginate, PVA and PVP were produced by freezing-thawing technique allowing adjustments of hydrogel composition and mechanical properties as demonstrated in compression studies performed in a biomimetic bioreactor.     

A flexible graphical user interface for embedding heterogeneousneural network simulators

A graphical user interface (GUI) for heterogeneous neural network simulators proposed in this article is intended to be of use both for the novice and for the experienced neural network user. For the novice, it provides an easy-to-use neural network simulation package that insulates the user from the requirements of knowing the simulator implementation details or the configuration file syntax. For the experienced neural network professional it provides an interface that is easily extensible to include any additional neural network simulator in its binary form. To satisfy both academic and personal computer environments, the GUI has been developed by using the free TCL/TK software package, available on workstations running Unix and on PCs running the free Linux operating system. Although the GUI and the embedded simulators have been successfully tested both in neural network research and training programs, a more extensive testing in undergraduate and graduate level classes is in progress     

Information maximization and independent component analysis; is there a difference?

This article provides a detailed and rigorous analysis of the two commonly used methods for redundancy reduction: linear independent component analysis (ICA) posed as a direct minimization of a suitably chosen redundancy measure and information maximization (InfoMax) of a continuous stochastic signal transmitted through an appropriate nonlinear network. The article shows analytically that ICA based on the Kullback-Leibler information as a redundancy measure and InfoMax lead to the same solution if the parameterization of the output nonlinear functions in the latter method is sufficiently rich. Furthermore, this work discusses the alternative redundancy measures not based on the Kullback-Leibler information distance. The practical issues of applying ICA and InfoMax are also discussed and illustrated on the problem of extracting statistically independent factors from a linear, pixel-by-pixel mixture of images.     

An adaptive partitioning approach for mining discriminant regions in 3D image data

Mining discriminative spatial patterns in image data is an emerging subject of interest in medical imaging, meteorology, engineering, biology, and other fields. In this paper, we propose a novel approach for detecting spatial regions that are highly discriminative among different classes of three dimensional (3D) image data. The main idea of our approach is to treat the initial 3D image as a hyper-rectangle and search for discriminative regions by adaptively partitioning the space into progressively smaller hyper-rectangles (sub-regions). We use statistical information about each hyper-rectangle to guide the selectivity of the partitioning. A hyper-rectangle is partitioned only if its attribute cannot adequately discriminate among the distinct labeled classes, and it is sufficiently large for further splitting. To evaluate the discriminative power of the attributes corresponding to the detected regions, we performed classification experiments on artificial and real datasets. Our results show that the proposed method outperforms major competitors, achieving 30% and 15% better classification accuracy on synthetic and real data respectively while reducing by two orders of magnitude the number of statistical tests required by voxel-based approaches.     

Die Abweichungsfläche bei Schnellregelvorgängen Beitrag zur Theorie der Schnellregelung

Zusammenfassung Die Berechnung der Fläche wurde angegeben, die die Lösung einer homogenen linearen Differentialgleichung beliebiger Ordnung, die eine stabile Bewegung darstellt, im Zeitintervale vont=0 bist= umschreibt. Danach ist an zwei behandelten Beispielen, die meistens bei der Schnellregelung vorkommen, gezeigt, wie diese Fläche nach einer sehr einfachen Gleichung zu bestimmen ist. Durch Vergleich der oszillographisch aufgenommenen Abweichungsflächen eines in Betrieb befindlichen Reglers kann man entweder einige Konstanten der Regelung ermitteln oder eine Rechnungskontrolle durchführen. Die Fläche kann weiterhin als ein Hilfsbegriff zu den theoretischen Untersuchungen auf dem Gebiete der Schnellregelung von Nutzen sein.     

A 90-nm logic technology featuring strained-silicon

A leading-edge 90-nm technology with 1.2-nm physical gate oxide, 45-nm gate length, strained silicon, NiSi, seven layers of Cu interconnects, and low-/spl kappa/ CDO for high-performance dense logic is presented. Strained silicon is used to increase saturated n-type and p-type metal-oxide-semiconductor field-effect transistors (MOSFETs) drive currents by 10% and 25%, respectively. Using selective epitaxial Si/sub 1-x/Ge/sub x/ in the source and drain regions, longitudinal uniaxial compressive stress is introduced into the p-type MOSEFT to increase hole mobility by >50%. A tensile silicon nitride-capping layer is used to introduce tensile strain into the n-type MOSFET and enhance electron mobility by 20%. Unlike all past strained-Si work, the hole mobility enhancement in this paper is present at large vertical electric fields in nanoscale transistors making this strain technique useful for advanced logic technologies. Furthermore, using piezoresistance coefficients it is shown that significantly less strain (/spl sim/5 /spl times/) is needed for a given PMOS mobility enhancement when applied via longitudinal uniaxial compression versus in-plane biaxial tension using the conventional Si/sub 1-x/Ge/sub x/ substrate approach.