Factorial coding of natural images: how effective are linear models in removing higher-order dependencies?

The performance of unsupervised learning models for natural images is evaluated quantitatively by means of information theory. We estimate the gain in statistical independence (the multi-information reduction) achieved with independent component analysis (ICA), principal component analysis (PCA), zero-phase whitening, and predictive coding. Predictive coding is translated into the transform coding framework, where it can be characterized by the constraint of a triangular filter matrix. A randomly sampled whitening basis and the Haar wavelet are included in the comparison as well. The comparison of all these methods is carried out for different patch sizes, ranging from 2x2 to 16x16 pixels. In spite of large differences in the shape of the basis functions, we find only small differences in the multi-information between all decorrelation transforms (5% or less) for all patch sizes. Among the second-order methods, PCA is optimal for small patch sizes and predictive coding performs best for large patch sizes. The extra gain achieved with ICA is always less than 2%. In conclusion, the edge filters found with ICA lead to only a surprisingly small improvement in terms of its actual objective.     

Quantum dots for human mesenchymal stem cells labeling. A size-dependent autophagy activation

Lately certain cytotoxicity of quantum dots (QDs) and some deleterious effects of labeling procedure on stem cells differentiation abilities were shown. In the present study we compared cytotoxicity and intracellular processing of two different-sized protein-conjugated QDs after labeling of the human mesenchymal stem cells (hMSC). An asymmetrical intracellular uptake of red (605 nm) and green (525 nm) quantum dots was observed. We describe for the first time a size-dependent activation of autophagy, caused by nanoparticles.     

Deutsche Nationalbibliothek 4. Erweiterungsbau in Leipzig – Besonderheiten bei der Unterfangung und der Bestandssicherung

Derzeit entsteht der 4. Erweiterungsbau der Deutschen Nationalbibliothek in Leipzig. Der neue Baukörper grenzt bereichsweise an die Bestandsgebäude und wurde 6 bis 8 m unterhalb der bestehenden Fundamente gegründet. Der setzungsempfindliche Baugrund infolge eines 4 m mächtigen Kohleflözes musste in der Planung besonders berücksichtigt werden. Um die Bestandsgebäude gegen Setzungen, Rissbildungen und Schiefstellungen zu schützen, wurden außergewöhnliche Sicherungsmaßnahmen realisiert: –·Zusammenspannen der Gebäude mittels Anordnung von Zugstäben –·Auskreuzung gefährdeter Bereiche durch Holz‐Fachwerkverbände –·Anwendung einer besonderen Technologie der HDI‐Unterfangung. Mit diesen Maßnahmen konnten ungleichmäßige Setzungen und Rissbildungen weitestgehend vermieden werden. The German National Library in Leipzig – 4^th extension – Special features of the underpinning and safety measures of inventory. At present the 4^th extension of the German National Library in Leipzig is under construction. The new building is near the existing buildings and was founded in 6 to 8 m below the existing foundations. The ground is liable to subsidence due to a 4 m thick coal seam. This had to be specially considered in the planning. To protect the existing buildings against settlements, cracking and misalignment extraordinary safety measures were implemented: –·tensioning arrangement of buildings by means of tension bars –·strengthening of vulnerable areas by timber trussed bond –·using a special technology of grouted underpinning With these measures, non‐uniform settlements and cracks could be largely avoided.     

Hochwasserschutz im Land Bremen – Anpassung an prognostizierte Klimaänderungen

Im Beitrag wird auf Besonderheiten bei der Umsetzung des Generalplans Küstenschutz Niedersachsen/Bremen im Land Bremen eingegangen. Im ersten Teil werden die Grundlagen und Ergebnisse des Generalplans sowie die administrative Aufstellung des Landes Bremen zur Anpassung des Hochwasserschutzes beschrieben. Das Instrument der Kostenvergleichsrechnung wird vorgestellt, welches in Bremen bereits im frühen Projektstadium zur Bewertung der Vorzugslösungen eingesetzt wird. Ein wichtiger Aspekt bei der Umsetzung des Generalplans sind die technischen Anforderungen, die sich aus den bestehenden Hochwasserschutzanlagen ergeben. Weiterhin müssen im Land Bremen die Maßnahmen zum Hochwasserschutz im Wesentlichen unter Berücksichtigung der bestehenden konstruktiv geprägten Ufer (Spundwände und Kaianlagen) umgesetzt werden. Dabei sind spezielle Anforderungen hinsichtlich der aktuellen und zukünftigen Nutzung insbesondere in den Hafenrevieren zu berücksichtigen. Beispielhaft werden begleitende Projekte der INROS LACKNER AG vorgestellt. Flood protection in the Federal State and the city of Bremen by adjustment of climate changes. The present article describes how the Federal State and the Free Hanseatic City of Bremen adapts its flood protection with respect to climate changes and global sea level rise. Design basics are compiled in the “Generalplan Küstenschutz Niedersachsen/Bremen” (General Plan for Coastal Protection – Lower Saxony/Bremen). Main results of the general plan will be described and administrative aspects of the adaptation of the flood protection elements in Bremen will be lined out. Special technical requirements as the consideration of existing walls and dikes will be described. Also requirements from harbour operation, recreational use and urban architecture have to be considered as the Bremen port partly undergoes a rapid change in this regard. The instrument of cost analysis will be introduced which is utilised in Bremen at an early stage of planning in order to develop cost effective measures of public founded projects. Mentioned topics will be described based on projects carried out by INROS LACKNER AG.     

Systematic approach to the synthesis of continuous-time cascaded sigma–delta modulators

This paper deals with a systematic approach to the synthesis of continuous-time cascaded sigma–delta modulators. Based on a system-theoretical model, a detailed derivation of the digital cancelation filters for continuous-time cascaded architectures is presented in order to achieve maximum signal-to-noise ratio together with optimal anti-aliasing performance. By using the same model, an exact equation for the performance loss of any cascaded architecture is derived. The latter is due to the scaling for stability and given relative to an ideal high-pass filter of the overall modulator order. Finally, an analytical calculation of optimal scaling coefficients in between the stages is performed, resulting in a limited search-space for these coefficients. Theoretical results are verified by simulations.     

MEtreePOLIS 1901-2111

As the natural world continues to change, it is clear that people would rather employ technology to adapt to shifting circumstances rather than alter their lifestyles to suit nature's demands. MEtreePolis is a timeline of crucial historical developments that explores the dichotomy of nature and technology. Commencing in 1901, it shoots past the present and into the future, closing in 2111. By providing an imaginative vision of tomorrow, Matthias Hollwich and Marc Kushner provide an entertaining argument for human manipulation of the environment, suggesting that it will inadvertently trigger ‘ecological salvation’ and ‘social utopia’. Copyright © 2010 John Wiley & Sons, Ltd.     

High quality extrudates from aluminum chips by new billet compaction and deformation routes

The effects of different billet preparation techniques as well as selection of various deformation routes and their influence on the final mechanical properties in chip extrusion was studied. The AA6060 chips were compacted into billets using various techniques and then extruded through the flat-face, porthole and ECAP dies to create different deformation routes. The microstructures and the mechanical properties of the chip extruded profiles were compared to cast billets extruded through the flat-face die under the same conditions. The proposed technology shows very promising results in terms of energy savings and production of the high quality engineered aluminum profiles.     

Effect of residual stress on the bending of aluminium

Skin passing or temper rolling introduces a strain gradient through the thickness of the sheet which, in turn, results in a residual stress profile through the thickness. These residual stresses can have a major effect on the elastic-plastic transition in bending operations, but the effect of residual stresses on downstream forming has yet to be determined.In this work, a commercial aluminium alloy, AA6063, was reduced in thickness by rolling in a laboratory mill to introduce residual stresses into the material. The strips were then tested in tension and pure bending and the material behaviour close to the elastic-plastic transition investigated. Substantial lowering of the elastic-plastic transition in the bending moment was observed while the opposite trend was found in the tensile test. The rolling process was analyzed using finite element analysis and the distribution of residual stresses determined; theoretical moment curvature characteristics were obtained using the output of this analysis as the input to the modelling for pure bending. The results show qualitatively how the material is softened in bending after rolling and demonstrate that this is partly due to the residual stress gradients in the material.