408 research outputs found

    About geometrical convergence of general iterative methods applied to nonunique solvable convex problems, Part I

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    AbstractGeneral conditions are given in a Hilbert space setting ensuring the geometrical convergence of a sequence (xk) to a fixed element x∗ of a convex and closed subset M. A thorough discussion to improve the occurring error estimates is added.The results are applied to the approximate solution of convex problems, where M is constituted by the solution set and (xk) is generated by a corresponding general iterative method

    Schwingungen als dynamische Systeme aus mathematischer Sicht

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    Schwingungen sind ein zentraler Gegenstand der Ingenieurausbildung. Sie spielen in allen Ingenieurdisziplinen eine wichtige Rolle. In mathematischen Lehrveranstaltungen kann man Studentenprojekte einbauen, in denen Programmsysteme zur Simulation des dynamischen Verhaltens von Schwingern entwickelt werden. Die Studenten sollen dabei auch lernen, die Korrektheit von Ergebnissen einzuschĂ€tzen. Dazu mĂŒssen sie die Fehlerquellen und ihre möglichen Auswirkungen kennen

    Positionen zur Mathematikausbildung von Ingenieuren

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    In den vom Gottlob-Frege-Zentrum initiierten Workshops Mathematik fĂŒr Ingenieure werden regelmĂ€ĂŸig Ideen und Erfahrungen zur StĂ€rkung und Modernisierung der Mathematikausbildung ausgetauscht. Die folgenden Positionen sind nicht neu, harren aber immer noch einer erfolgreichen Umsetzung. Sie sollen den vielfĂ€ltigen BemĂŒhungen Nachdruck verleihen und das BĂŒndnis aller Betroffenen organisieren

    „Es fĂŒhrt ĂŒber den Main eine BrĂŒcke von Stein“. Die BrĂŒcken von Frankfurt am Main im langen 19. Jahrhundert

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    Der Beitrag untersucht, wie die Alte BrĂŒcke in Frankfurt am Main im 19. Jahrhundert in verkehrstechnischer Hinsicht durch andere BrĂŒcken ergĂ€nzt und teilweise substituiert wurde. Beim Neubau dieser BrĂŒcke im frĂŒhen 20. Jahrhundert, der wegen der Behinderung der Schifffahrt und mangelnder LeistungsfĂ€higkeit fĂŒr den Straßenverkehr notwendig wurde, verzichtete man auf eine Ă€ußerlich sichtbare moderne Gestaltung und knĂŒpfte durch BrĂŒckendesign und Formensprache am historischen Vorbild an. Die groß dimensionierte BrĂŒckenweihe 1926 nutzte die Stadt Frankfurt, um ihre reichsweite Bedeutung und ihren Anspruch als „Verkehrsstadt“ zum Ausdruck zu bringen.“A stone bridge leads across the Main”: Bridges in Frankfurt am Main in the long 19th centuryThe article analyzes how, from the point of view of road traffic organization, the Old Bridge in Frankfurt am Main was completed and in the 19th c. partly replaced by other bridges. During the reconstruction of this bridge in the early 20th century, necessary due to ship traffic jams and inefficiencies of urban traffic, modern design was abandoned for the style and form of the bridge referring to the historical prototype. The grand opening of the bridge in 1926 was used by Frankfurt to emphasize the city‘s importance and its claims for the role of a communication centre. Translated by Anna Maleszka„Przez Men prowadzi most z kamienia”. Mosty we Frankfurcie nad Menem w dƂugim XIX wiekuW artykule przeanalizowano, w jaki sposĂłb z punktu widzenia organizacji ruchu drogowego Stary Most we Frankfurcie nad Menem zostaƂ uzupeƂniony i częƛciowo zastąpiony w XIX wieku innymi mostami. Podczas przebudowy tego mostu na początku XX wieku, koniecznej z powodu utrudnieƄ w ruchu statkĂłw oraz maƂej wydajnoƛci w ruchu drogowym, zrezygnowano z wyraĆșnie nowoczesnego projektu i nawiązano poprzez stylistykę oraz formę mostu do historycznego pierwowzoru. Przeprowadzone z rozmachem uroczyste otwarcie mostu w 1926 roku zostaƂo przez Frankfurt wykorzystane do podkreƛlenia paƄstwowego znaczenia tego miasta i jego roszczeƄ do roli centrum komunikacyjnego. TƂumaczenie Renata SkowroƄsk

    Moderne Mathematikausbildung fĂŒr Ingeneure

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    Wir brauchen gut ausgebildete und flexibel einsetzbare Ingenieure, um die KonkurrenzfĂ€higkeit unserer Region zu sichern. Eine fundierte und moderne Mathematikausbildung fĂŒr Ingenieure ist daher unverzichtbar. Da die mathematischen Vorkenntnisse der StudienanfĂ€nger schlecht sind und tendenziell weiter sinken, mĂŒssen wir uns Gedanken sowohl zur Verbesserung der Vorkenntnisse als auch zur weiteren Qualifizierung der Mathematikausbildung durch Einsatz neuer Lehrformen und neuer Hilfsmittel machen. Die VortrĂ€ge des Minisymposiums stellen einen guten Querschnitt zu dieser Problematik dar. Sie knĂŒpfen an das an, was im norddeutschen Raum in den Workshops "Mathematik fĂŒr Ingenieure" seit dem Jahre 2000 diskutiert und ausgewertet wird. Da die Probleme in ganz Deutschland und Europa Ă€hnlich sind, gibt es von Anfang an BemĂŒhungen, den Erfahrungsaustausch mit anderen Zentren zu vernetzen. Das Gottlob-Frege-Zentrum der Hochschule Wismar ist Sattelite Centre of UICEE (siehe Literatur). Das Minisymposium stellt ein wichtiges Bindeglied auf diesem Wege dar. Die Organisatoren werden auch auf kĂŒnftigen Jahrestagungen eine moderne Mathematikausbildung fĂŒr Ingenieure propagieren

    Conflicts of interest in medicine and their management: current challenges and initiatives in Germany

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    Conflicts of interest (COI) in healthcare have increasingly gained attention in the lay press as well as among healthcare professionals. COIs increase the risk of undue influence on professional decision making and may have far-reaching consequences in healthcare. Therefore, it is essential to develop strategies to deal with such risk situations in order to prevent negative outcomes for patients and the health care system. This article describes recent research on COIs in Germany as well as initiatives aiming at more transparency and better management of COIs in Germany

    Quantification of large and middle proteins of hepatitis B virus surface antigen (HBsAg) as a novel tool for the identification of inactive HBV carriers

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    Objective Among individuals with chronic hepatitis B, those with hepatitis B e-antigen (HBeAg)-negative chronic hepatitis (CHB) can be difficult to distinguish from those with HBeAg-negative chronic HBV infection, also referred to as inactive HBV carriers (ICs), but both require different medical management. The level of HBV surface antigen (HBsAg) has been proposed as a marker to discriminate between chronic infection and hepatitis stages. HBsAg consists of large, middle and small HBs. The aim of this study was to determine whether the composition of HBsAg improved the identification of ICs among HBsAg-positive subjects with different phases of HBV infections. Design HBV large surface proteins (LHBs) and HBV middle surface proteins (MHBs) were quantified in serum samples from 183 clinically well-characterised untreated patients with acute (n=14) HBV infection, ICs (n=44), CHBs (n=46), chronic HBeAg-positive phase (n=68) and hepatitis delta coinfection (n=11) using an ELISA, with well-defined monoclonal antibodies against the preS1 domain (LHBs) and the preS2-domain (MHBs). A Western blot analysis was used to verify the quantitation of the components of HBsAg. Total HBsAg was quantified using a modified commercially available assay (HBsAg V. 6.0, Enzygnost, Siemens, Erlangen). Results The composition of HBsAg showed specific patterns across different phases of hepatitis B. Individuals in the IC phase had significantly lower proportions of LHBs and MHBs than patients in acute or chronic phases irrespective of their HBV e-antigen status (p< 0.0001) or HBsAg level. Both LHBs and MHBs ratios better predicted the IC phase than total HBsAg levels. Conclusion Quantification of MHBs, particularly LHBs represents a novel tool for the identification of the IC stage

    Global Standards in Action: Insights from Anti-Money Laundering Regulation

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    As organizations have come under the increasing influence of global rules of all sorts, organization scholars have started studying the dynamics of global regulation. The purpose of this article is to identify and evaluate the contribution to this interdisciplinary field by the ‘Stockholm Centre for Organisational Research’. The latter’s key proposition is that while global regulation often consists of voluntary best practice rules it can nevertheless become highly influential under certain conditions. We assess how innovative this approach is using as a benchmark the state of the art in another field of relevance to the study of global regulation, i.e. ‘International Relations’. Our discussion is primarily theoretical but we draw on the case of global anti-money laundering regulation to illustrate our arguments and for inspirations of how to further elaborate the approach

    Field-free deterministic ultra fast creation of skyrmions by spin orbit torques

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    Magnetic skyrmions are currently the most promising option to realize current-driven magnetic shift registers. A variety of concepts to create skyrmions were proposed and demonstrated. However, none of the reported experiments show controlled creation of single skyrmions using integrated designs. Here, we demonstrate that skyrmions can be generated deterministically on subnanosecond timescales in magnetic racetracks at artificial or natural defects using spin orbit torque (SOT) pulses. The mechanism is largely similar to SOT-induced switching of uniformly magnetized elements, but due to the effect of the Dzyaloshinskii-Moriya interaction (DMI), external fields are not required. Our observations provide a simple and reliable means for skyrmion writing that can be readily integrated into racetrack devices

    Consensus recommendations of the german consortium for hereditary breast and ovarian cancer

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    BACKGROUND: The German Consortium for Hereditary Breast and Ovarian Cancer (GC-HBOC) has established a multigene panel (TruRiskÂź) for the analysis of risk genes for familial breast and ovarian cancer. SUMMARY: An interdisciplinary team of experts from the GC-HBOC has evaluated the available data on risk modification in the presence of pathogenic mutations in these genes based on a structured literature search and through a formal consensus process. KEY MESSAGES: The goal of this work is to better assess individual disease risk and, on this basis, to derive clinical recommendations for patient counseling and care at the centers of the GC-HBOC from the initial consultation prior to genetic testing to the use of individual risk-adapted preventive/therapeutic measures
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