Computing Delay Resistant Railway Timetables

In the past, much research had been dedicated to compute optimum railway timetables. A typical objective was the minimization of passenger waiting times. But only the planned nominal waiting times were addressed, whereas delays, as they occur in daily operation, were neglected. Rather, conceptually, delays were treated mainly in an online-context, and solved as a separate optimization problem, called delay management

Structures, energetics, and dynamics of helium adsorbed on isolated fullerene ions

Helium adsorbed on C60+ and C70+ exhibits phenomena akin to helium on graphite. Mass spectra suggest that commensurate layers form when all carbon hexagons and pentagons are occupied by one He each, but that the solvation shell does not close until 60 He atoms are adsorbed on C60+, or 62 on C70+. Molecular dynamics simulations of C 60Hen+ at 4 K show that the commensurate phase is solid. Helium added to C60He32+ will displace some atoms from pentagonal sites, leading to coexistence of a registered layer of immobile atoms interlaced with a nonregistered layer of mobile atomsThis work was supported by MICINN projects FIS2010-15127, ACI2008-0777, CTQ2010-17006, Consolider-Ingenio CSD2007-00010, CAM program NANOBIOMAGNET S2009/MAT1726, the Austrian Science Fund, Wien (FWF, projects P19073, L633, and I200 N29), the European Commission, Brussels (ITS-LEIF), and the European COST Action CM0702

Der Mediensport Olympia - ein globales Integrationsritual?

Die Olympischen Spiele wirken als ein Integrationsritus in einer sich globalisierenden Welt. Der Sport überwindet die Länder-, Kultur- und Rassengrenzen und vereint die Öffentlichkeit mithilfe der Medien. Diese inszenieren die Sportarten gemäß ihrer Wirkungslogik, und verändern somit den Sport selbst. Trotz Skandalen nimmt die Bedeutung der Spiele stetig zu, sie erreichen mit der Eröffnungsfeier das weltweit größte (Fernseh-)Publikum. Diese Feier ist ein globaler sakraler Ritus. Besonders das Fernsehen lässt alle um Ritus teilhaben. Der Sport als soziales Handeln vermittelt einen Glauben an Fortschritt durch Leistung, und die Zuschauer können mithilfe der Medien auch teilnehmen. In Zeiten des Wandels wird der Ritus wichtig für die Gemeinschaft.The Olympic Games appear to be a rite of integration in a world of increasing globalization. Sport overcomes national, cultural und racial boundaries, und unites the public with the help of the media. The media (re)produce the different sports according to the functional logic of their medial presentation und therefore change the sports itself: Economy has replaced morality as the highest precept. Despite certain scandals, the Games become more und more significant. The opening ceremony reaches the largest (TV-)audience worldwide. This ceremony is a global religious rite which could have never been accomplished without the media. It is especially television that enables everyone to be a part of the rite. Sport as social action educates a belief in Progress through achievement, and the audience can participate with the help of the media. In times of constant changes, this rite becomes highly important to the community

Coronavirus-Pandemie: Die Feiertage und den Jahreswechsel für einen harten Lockdown nutzen : 7. Ad-hoc-Stellungnahme zr Coronavirus-Pandemie - 08.Dezember 2020

Die gegenwärtige Situation ist nach wie vor ernst und droht sich weiter zu verschärfen. Trotz des seit Anfang November in Deutschland geltenden Teil-Lockdowns sind die Infektionszahlen auf einem sehr hohen Niveau. Jeden Tag sterben mehrere Hundert Menschen. Die Krankenhäuser und insbesondere das medizinische Personal sind bereits jetzt an ihren Grenzen und die Gesundheitsämter überlastet. Um die Kontrolle über das Infektionsgeschehen zurückzuerlangen, empfiehlt die Nationale Akademie der Wissenschaften Leopoldina in der Ad-hoc-Stellungnahme „Coronavirus-Pandemie: Die Feiertage und den Jahreswechsel für einen harten Lockdown nutzen“ ein zweistufiges Vorgehen. Die Rahmenbedingungen ‒ Weihnachtsferien in Bildungseinrichtungen und eingeschränkter Betrieb in vielen Unternehmen und Behörden – bieten die Chance, in der Eindämmung der Pandemie ein großes Stück voranzukommen

Progress in hybrid plasma wakefield acceleration

Plasma wakefield accelerators can be driven either by intense laser pulses (LWFA) or by intense particle beams (PWFA). A third approach that combines the complementary advantages of both types of plasma wakefield accelerator has been established with increasing success over the last decade and is called hybrid LWFA→PWFA. Essentially, a compact LWFA is exploited to produce an energetic, high-current electron beam as a driver for a subsequent PWFA stage, which, in turn, is exploited for phase-constant, inherently laser-synchronized, quasi-static acceleration over extended acceleration lengths. The sum is greater than its parts: the approach not only provides a compact, cost-effective alternative to linac-driven PWFA for exploitation of PWFA and its advantages for acceleration and high-brightness beam generation, but extends the parameter range accessible for PWFA and, through the added benefit of co-location of inherently synchronized laser pulses, enables high-precision pump/probing, injection, seeding and unique experimental constellations, e.g., for beam coordination and collision experiments. We report on the accelerating progress of the approach achieved in a series of collaborative experiments and discuss future prospects and potential impact

Evaluating line concepts using travel times and robustness:simulations with the LinTim toolbox

Line planning is an early step in the planning process in public transportation, usually followed by designing the timetable. The problems related to both steps are known to be NP-hard, and an integrated model finding a line plan and a timetable simultaneously seems out of scope from a computational point of view. However, the line plan influences also the quality of the timetable to be computed in the next planning step. In this paper we analyze the impact of different line planning models by comparing not only typical characteristics of the line plans, but also their impact on timetables and their robustness against delays. To this end, we set up a simulation platform LinTim which enables us to compute a timetable for each line concept and to experimentally evaluate its performance under delays. Using the German railway intercity network, we evaluate the quality of different line plans from a line planning, a timetabling, and a delay management perspective