Fault tolerant embedded systems design by multi-objective optimization

The design of fault tolerant systems is gaining importance in large domains of embedded applications where design constrains are as important as reliability. New software techniques, based on selective application of redundancy, have shown remarkable fault coverage with reduced costs and overheads. However, the large number of different solutions provided by these techniques, and the costly process to assess their reliability, make the design space exploration a very difficult and time-consuming task. This paper proposes the integration of a multi-objective optimization tool with a software hardening environment to perform an automatic design space exploration in the search for the best trade-offs between reliability, cost, and performance. The first tool is commanded by a genetic algorithm which can simultaneously fulfill many design goals thanks to the use of the NSGA-II multi-objective algorithm. The second is a compiler-based infrastructure that automatically produces selective protected (hardened) versions of the software and generates accurate overhead reports and fault coverage estimations. The advantages of our proposal are illustrated by means of a complex and detailed case study involving a typical embedded application, the AES (Advanced Encryption Standard).

Targetless image-based method for measuring displacements and strains on concrete surfaces with a consumer camera

Measurement of concrete strain through non-invasive methods is of great importance in civil engineering and structural analysis. Traditional methods use laser speckle and high quality cameras that may result too expensive for many applications. Here we present a method for measuring concrete deformations with a standard reflex camera and image processing for tracking objects in the concretes surface. Two different approaches are presented here. In the first one, on-purpose objects are drawn on the surface, while on the second one we track small defects on the surface due to air bubbles in the hardening process. The method has been tested on a concrete sample under several loading/unloading cycles. A stop-motion sequence of the process has been captured and analyzed. Results have been successfully compared with the values given by a strain gauge. Accuracy of our methods in tracking objects is below 8 μm, in the order of more expensive commercial devices.

Coagent Modified Polypropylene Prepared by Reactive Extrusion: A New Look Into the Structure-Property Relations of Injection Molded Parts

Peroxide-mediated reactive extrusion of linear isotactic polypropylene (L-PP) was conducted in the presence of trimethylolpropane trimethacrylate (TMPTMA) and triallyl trimesate (TAM) coagents, using a twin screw extruder. The resulting coagent-modified polypropylenes (CM-PP) had higher viscosities and elasticities, as well as increased crystallization temperature compared to PP reacted only with peroxide (DCP-PP). Additionally, deviations from terminal flow, and strain hardening were observed in PP modified with TAM, signifying the presence of long chain branching (LCB). The CM-PP formulations retained the modulus and tensile strength of the parent L-PP, in spite of their lower molar mass and viscosities, whereas their elongation at break and the impact strength were better. This was attributed to the finer spherulitic structure of these materials, and to the disappearance of the skin-core layer in the injection molded specimens.

Gazprom’s expansion in the EU: co-operation or domination? OSW Report, October 2009. Second edition, revised

Introduction. The energy sector, especially with regard to the gas trade, is one of the key areas of co-operation between the EU and Russia. However, the form this co-operation has taken has been giving rise to some concern, both in Brussels and in the EU member states. Questions arise as to whether the EU has not become excessively dependent on Russia for energy, and whether the presence of the Russian gas monopoly in the EU does not enable Russian interference with the development of EU energy policy. The objective of this series of OSW reports (for the previous edition,see Gazprom’s expansion in the EU: co-operation or domination? April 2008 – pdf 1.2 MB) is to provide facts which will permit an accurat answer to these questions to be formulated. Over the course of last year, two new factors strongly affected Gazprom’s capability to operate on the EU market. One was the ongoing global economic crisis, which has depressed demand for gas both in Russia and in Europe. Gazprom has cut both its own production and the quantities of gas it purchases from the Central Asian states, and the decrease in export revenues has forced the company to modify some of its current investment plans. Less demand for gas and the need to reduce production are also having a positive impact – the Russian company is likely to avoid the difficulties in meeting all of its export commitments which, only a year or so ago, it was expected to experience. The other factor affecting Gazprom’s expansion in Europe is the observed radicalisation of the rhetoric and actions of both the company itself and of the Russian authorities with regard to the gas sector as broadly understood. The gas crisis between Russia and Ukraine in January 2009, which resulted in a two-week interruption of gas supplies from Russia to Europe via Ukraine, was the most prominent example of this radicalisation. The hardening of rhetoric in the ongoing energy talks with the EU and other actors, and increased political and business activities designed to promote Russian gas interests in Europe, in particular the lobbying for the Nord Stream and South Stream projects, are further signs of this shift in tone. These issues raise the question of whether, and to what extent, the current condition of Gazprom’s finance will permit the company to implement the infrastructural projects it has been endorsing and its other investment plans in Europe. Another important question is whether the currently observed changes in how Gazprom operates will take on a more permanent character, and what consequences this will have for the European Union. The first part of this report discusses Gazprom’s production and export potential. The second comprehensively presents the scope and nature of Gazprom’s economic presence in the EU member states. Finally, the third part presents the Russian company’s methods of operation on foreign markets. The data presented in the report come mainly from the statistics of the International Energy Agency, the European Commission and Gazprom, as well as the Central Bank of Russia and the Russian Statistical Office. The figures presented here also include proprietary calculations by the OSW based on figures disclosed by energy companies and reports by professional press and news agencies.

Properties of granular analogue model materials: A community wide survey

We report the material properties of 26 granular analogue materials used in 14 analogue modelling laboratories. We determined physical characteristics such as bulk density, grain size distribution, and grain shape, and performed ring shear tests to determine friction angles and cohesion, and uniaxial compression tests to evaluate the compaction behaviour. Mean grain size of the materials varied between c. 100 and 400 μm. Analysis of grain shape factors shows that the four different classes of granular materials (14 quartz sands, 5 dyed quartz sands, 4 heavy mineral sands and 3 size fractions of glass beads) can be broadly divided into two groups consisting of 12 angular and 14 rounded materials. Grain shape has an influence on friction angles, with most angular materials having higher internal friction angles (between c. 35° and 40°) than rounded materials, whereas well-rounded glass beads have the lowest internal friction angles (between c. 25° and 30°). We interpret this as an effect of intergranular sliding versus rolling. Most angular materials have also higher basal friction angles (tested for a specific foil) than more rounded materials, suggesting that angular grains scratch and wear the foil. Most materials have an internal cohesion in the order of 20–100 Pa except for well-rounded glass beads, which show a trend towards a quasi-cohesionless (C < 20 Pa) Coulomb-type material. The uniaxial confined compression tests reveal that rounded grains generally show less compaction than angular grains. We interpret this to be related to the initial packing density after sifting, which is higher for rounded grains than for angular grains. Ring-shear test data show that angular grains undergo a longer strain-hardening phase than more rounded materials. This might explain why analogue models consisting of angular grains accommodate deformation in a more distributed manner prior to strain localisation than models consisting of rounded grains.

Theoretical prediction of plastic strains of polycrystals,

Mode of access: Internet.

Xenophontis opuscula politica, equestra et venatica, cum Arriani libello De venatione,

Greek text, Latin introduction and notes.

Disputatio academica de Amoso.

Thesis (D. Theol.)--Leyden.

Iron and steel : principles of manufacture, structure, composition and treatment ...

Principles of iron and steel manufacture.--Steel castings.--Steel hardening metals.--Development and use of high-speed steel.--Hardening steel, by E.R. Markham.--Case-hardening.--The Brinell method of testing the hardness of metals, by E. Oberg.

Bibliotheca critica nova.

Mode of access: Internet.

Circularis doctrinae de sublimibus libri duo.

Mode of access: Internet.

Reliquiae doctrinae.

Mode of access: Internet.

Letters of the Hon. C.F. Cleveland, and Hon. Henry Hubbard, Governors of Connecticut and New Hampshire, to Samuel Ward King, the charter governor of Rhode Island, refusing to deliver up Thomas Wilson Dorr, ...

Also, the letter of the Hon. Marcus Morton, and others, to the Suffrage Clam-bake.

The experienced English housekeeper : for the use and ease of ladies, housekeepers, cooks, &c., written purely from practice : dedicated to the Hon. Lady Elizabeth Warburton, whom the author lately served as housekeeper : consisting of several hundred original receipts, most of which never appeared in print /

Includes recipes for wine, mead, and other liquors; illustrations of kitchen stoves using coal; illustrations of layout of dishes for multi-course meal. Sample recipes: To bake herrings, To make cream pancakes, To make a blanc-mange of isinglass, To make cowslip wine.

M. Tullii Ciceronis De legibus libri tres /

Mode of access: Internet.