5,724 research outputs found

    First Alignment of the Complete CMS Tracker

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    This conference proceeding presents the first results of the full CMS Tracker alignment based on several million reconstructed tracks from the cosmic data taken during the commissioning runs with the detector in its final position and magnetic field present. The all-silicon design of the CMS Tracker poses new challenges in aligning a complex system with 15\,148 silicon strip and 1440 silicon pixel modules. For optimal track-parameter resolution, the position and orientation of its modules need to be determined with a precision of about one micrometer. The modules, well illuminated by cosmic ray particles, were aligned using two track-based alignment algorithms in sequence in combination with survey measurements. The resolution in all five track parameters is controlled with data-driven validation of the track parameter measurements near the interaction region, and tested against prediction with detailed detector simulation. An outlook for the expected tracking performance with the first proton collisions is given.Comment: To appear in the Proceedings of the 7th International "Hiroshima" Symposium on the Development and Application of Semiconductor Tracking Detector

    Cluster-Building and the Transformation of the University

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    Eine der bemerkenswerten neueren VerĂ€nderungen von UniversitĂ€ten in vielen westlichen LĂ€ndern besteht in BemĂŒhungen, Forschungscluster, »kritische Massen«, Zentren etc. zu errichten. In diesem Beitrag wollen wir die enge Verbindung zwischen Cluster-Bildung auf der einen Seite und zwei weiteren neueren Transformationen des Hochschulsystems untersuchen: Die entstehende Actorhood, die sich nicht zuletzt in der StĂ€rkung von Hochschulleitungen manifestiert, und die an letztere adressierte Erwartung, Profilbildung an ihren UniversitĂ€ten voranzutreiben. Wir beginnen mit einer Beschreibung dessen, was wir unter Clustern verstehen. Anschließend fragen wir im Hinblick auf Forscherinnen und Forscher einerseits und Hochschulleitungen andererseits, warum sich einige von den ersteren und die letzteren fĂŒr Cluster-Bildung interessieren, wĂ€hrend andere der erstgenannten Gruppe sie ablehnen. Danach betrachten wir das Zusammenspiel von top-down und bottom-up-AktivitĂ€ten. Hier unterscheiden wir zwischen der Errichtung neuer Cluster und dem Umgang mit bestehenden. So folgen wir dem Lebenszyklus eines Clusters vom Anfang bis zum Ende.   One of the noticeable recent changes of universities in many Western countries consists in efforts to establish research clusters, »critical masses«, centers etc. In this paper we want to explore the tight connection between cluster-building, on the one hand, and two other recent transformations of the university system: the emerging actorhood of universities which manifests itself mainly in the strengthening of university leadership, and the expectation directed at university leadership that it should promote profile-building of its university. We start with a descriptive exposition of what is meant by clusters. Then we ask with respect to researchers, on the one hand, and university leadership, on the other, why the latter and some of the former have got interested in cluster-building whereas others of the former oppose. After that we take a look at the interplay of top-down and bottom-up activities involved in cluster-building. Here we distinguish the creation of a new cluster from the handling of an existing one. In this way we follow the life-cycle of a cluster from its beginning to its end

    The Internet Activities of FiBL

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    The poster presents the main internet sites maintained by FIBL in 2002: www.fibl.org www.oekolandbau.de http://www.organicxseeds.com

    Euroland: recovery will slowly gain momentum

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    Economic activity in the euro area has weakened since last summer. In the second half of 2002, real GDP increased at an annualized rate of around 1 percent only. Economy-wide capacity utilization has further declined and the situation on labor markets has worsened. The increase in consumer prices has calmed down somewhat after an acceleration at the beginning of last year. Still, the inflation rate remains surprisingly high against the background of weak economic activity that has already lasted for two years. Monetary policy in the euro area is clearly expansionary. With only about 0.5 percent, the real interest rate is currently quite low by historical standards. Moreover, the nominal interest rate is well below the rate implied by the standard Taylor rule, even when low estimates of the current size of the output gap and the equilibrium real interest rate are employed in the calculation of the rule. Still, monetary policy is probably not too expansionary. According to theory, the equilibrium real interest rate may be substantially below the long-run average real interest rate in situations such as the current one with depressed income and profit expectations. However, these considerations also imply that the ECB should bring the real interest rate back towards the long-run average once the depressing factors will have vanished. The situation of public finances in the euro area deteriorated further in the course of last year, with the aggregated budget in the countries of the euro area approaching a deficit of 2.3 percent of GDP in 2002. The cyclically adjusted budget deficit in the euro area was as high as in 1998, the year immediately before the beginning of the third stage of the Economic and Monetary Union. Whereas most countries have in the meantime complied with the goal of the Stability and Growth Pact to at least balance the budget over the medium term, the budget deficit in Germany, France, Italy and Portugal remained high both in actual and in structural terms. The governments of the three largest countries of the euro area are not likely to switch towards a policy of fiscal consolidation based on cuts in primary spending in 2003 and 2004. Moderate wage settlements would be appropriate in the current cyclical situation. However, wage increases have not slowed down over the past year, and are not expected to do so to any meaningful extent this year and next, reflecting the judgment that labor market rigidities will remain significant over the forecast horizon. Nevertheless, as employment is likely to be slow in responding to a recovery in production, the rise in unit labor costs will decelerate considerably, improving the chances that inflation will fall persistently below 2 percent. The leading indicators suggest that economic activity in the euro area will remain weak in the first half of this year. Under the assumption that the war in the Gulf region is of short duration and that the global political situation calms down afterwards, dampening factors from the Iraq conflict are expected to wane. Impulses from expansionary monetary policy will then increasingly take effect and domestic driving forces will gain the upper hand. We expect real GDP to increase by 1.0 percent and by 2.6 percent in 2003 and 2004, respectively. The situation on the labor market will start to improve towards the end of this year only. Inflation will be moderate over the forecast horizon. In 2004, consumer prices will probably rise by 1.9 percent on average, after 2.2 percent this year. --

    Security and Privacy of Personal Health Records in Cloud Computing Environments – An Experimental Exploration of the Impact of Storage Solutions and Data Breaches

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    In the course of the digitization in healthcare, the collection and central storage of large health-related datasets in clouds in the form of personal health records is growing. However, the use of cloud services for sensitive data is associated with security and privacy risks. Further, the delegation of control over security and privacy measures to the cloud provider requires trust on the users’ side. In order to investigate the role of security and privacy when storing and processing patient data, we conducted an online experiment, in which third-party cloud services are compared to private on-premise data centers. Additionally, we examine the impact of data breaches on the perceived security, privacy, control and trust in both storage scenarios. Our results indicate that cloud-based personal health records still face concerns regarding perceived security, privacy, control and trust amongst end-users. Nevertheless, after a data breach, no significant differences between both solutions exist

    Berechnung der Schutzwirkung von Schutzdioden in Leistungsschnittstellen von LuftfahrtgerÀten durch die Lambert-W-Funktion

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    FĂŒr die Anwendung als Spannungsschutzelemente entwickelte Zener-Dioden sind hĂ€ufigste Wahl zur Begrenzung von transienten Spannungen, die in einem Energieversorgungsnetz eines Flugzeugs auftreten. Die induzierende Wirkung des Stromes, die bei einem Blitzeinschlag in die FlugzeughĂŒlle auftritt, fĂŒhrt zu einer SpannungsĂŒberhöhung, die auf die elektrischen Schnittstellen der GerĂ€te und Anlagen wirkt. Spannungsform und Energie sind durch Feldstudien ermittelt worden und flossen in PrĂŒfnormen ein. Zur Qualifikation eines GerĂ€tes werden die PrĂŒfpulse auf die elektrischen Schnittstellen angewandt und sind Belastungen, die beim Schaltungsentwurf berĂŒcksichtigt werden mĂŒssen. Wird eine transformatorische Kopplung angewandt und die Energie des PrĂŒfpulses auf ein KabelbĂŒndel eingekoppelt, so ist die aufgenommene Energie eines Schutzelements stark von GrĂ¶ĂŸen außerhalb der Schnittstelle abhĂ€ngig. Messtechnisch kann sie aus Strom und Spannung bestimmt werden, jedoch ist bei Pulsversuchen die Spannung weitaus schwerer zu messen als der Strom. Die galvanische Kopplung der Tastköpfe und die induzierten Spannungen fĂŒhren zu SchwingungsvorgĂ€ngen in den aufgezeichneten Spannungen. So bleibt es wĂŒnschenswert, alleine aus dem gemessenen Strom die aufgenommen Energie zu bestimmen. Die zugefĂŒhrte Energie bestimmt die Temperaturerhöhung durch den Puls und ist ĂŒber die Grenztemperatur des Halbleitermaterials wesentliches Selektionsmerkmal. Da die Temperatur im Halbleiter nicht direkt messbar ist, kann sie nur ĂŒber die Energiebilanz unter ein thermisches Modell indirekt bestimmt werden. Schon bei einer Schaltung aus Diode, Vorwiderstand und Spannungsquelle lĂ€sst sich erkennen, dass eine explizite Lösung der Netzwerkgleichungen der Spannung nicht möglich ist. Nur die AbhĂ€ngigkeit des Stromes von der Spannung ist hinlĂ€nglich bekannt. Abhilfe schafft die Lambert-W-Funktion, die zu den weniger bekannten transzendenten Funktionen gehört. Wird ein Diodenmodell mit Exponentialfunktion in der Stromsenke und einem konstanten Vorwiderstand angenommen, so kann der Zusammenhang von Strom und Spannung mit der Lambert-W-Funktion ausgedrĂŒckt werden und eine analytische Funktion ist als Inverse verfĂŒgbar. Dies erlaubt das symbolische Rechnen und erweitert die Wahl der Berechnungsmethoden erheblich. Aus dem Datenblatt kann die maximale Energie entnommen werden und ist mit der zugefĂŒhrten Energie aus den Versuchen zu vergleichen. Zur Qualifikation von LuftfahrtgerĂ€ten werden Verfahren und Pulse gemĂ€ĂŸ ED-14 verwendet und von Anforderungen der Flugzeughersteller ergĂ€nzt [13]. Der Ein schlag eines Blitzes wĂ€hrend des Fluges durchlĂ€uft zeitliche Phasen, die unterschiedliche Pulse auf Stromversorgungsund Signalleitungen nach sich ziehen. Daraus wurden fĂŒnf Pulsformen identifiziert und sind bei der Qualifikation auf den PrĂŒfling oder den Kabelbaum zu applizieren. Pulsformen und PrĂŒfmethode sind der ED-84 entnommen worden [9]. Die Wahl der Pulsformen und ihrer Amplituden hĂ€ngt vom Ort des GerĂ€tes im Flugzeug und dem PrĂŒfschĂ€rfegrad ab

    Measurements of sin 2ÎČ using charmonium and open charm decays at LHCb

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    The C ⁣PC\!P violation observables SfS_f and CfC_f in the decays of B0B^0 and B‟0\kern 0.18em\overline{\kern -0.18em B}{}^0 mesons to the J ⁣/â€‰âŁÏˆKS0J\!/\!\psi K^0_S final state and to the D+D−D^+ D^- final state are measured with a data sample corresponding to an integrated luminosity of 3fb−13 fb^{-1} collected with the LHCb experiment in proton-proton collisions at centre-of-mass energies of 77 and 8 TeV8 ~TeV. The analysis of the decay-time evolution of 41560 B0 ⁣→J ⁣/â€‰âŁÏˆKS041560 ~B^0\!\rightarrow J\!/\!\psi K^0_S decays yields \begin{align*} S_{J\!/\!\psi K^0_S} &= \phantom{-}0.731 \, \pm 0.035 \, \text{(stat)} \pm 0.020 \, \text{(syst)}\,, \\ C_{J\!/\!\psi K^0_S} &= - 0.038 \, \pm 0.032 \, \text{(stat)} \pm 0.005 \, \text{(syst)}\,, \end{align*} which is consistent with the current world averages and with the Standard Model expectations. In a flavour-tagged, decay-time-dependent analysis of 1410 B0 ⁣→D+D−1410 ~B^0\!\rightarrow D^+ D^- decays the following results are determined: \begin{align*} S_{D^+ D^-} &= -0.54 \, ^{+0.17}_{-0.16} \, \text{(stat)} \pm 0.05 \, \text{(syst)}\,, \\ C_{D^+ D^-} &= \phantom{-}0.26 \, ^{+0.18}_{-0.17} \, \text{(stat)} \pm 0.02 \, \text{(syst)}\,. \end{align*} With these results high-order Standard Model corrections, which could lead to differences between the absolute values of the obtained observables of the two decay modes, are constrained to be small
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