Wenn die Akzeptanz der Supportangebote sinkt – Fehlentwicklung oder strukturelle Notwendigkeit

Das Supportangebot des E-Learning Zentrums der TU Wien wurde im Rahmen des Projekts Delta 3 entwickelt und war damit an der Nominierung als Finalist des Medida Prix 2007 nominiert. In den zwölf Monaten seit der Einreichung ging die Nachfrage – speziell für die Weiterbildungsworkshops – deutlich zurück. Die möglichen Gründe dafür werden selbstkritisch und auch aus strategischer Sicht analysiert, um daraus potenzielle Verbesserungsmaßnahmen ableiten zu können. (DIPF/ Orig.

Codes for QPSK modulation with invariance under 90 degrees rotation

The new rate 1/2 nonlinear convolutional codes for quadrature phase shift keying (QPSK) modulation allow the achievement of full 90 degree rotational invariance of coded QPSK signal sequences at no significant loss in real coding gains when compared to linear codes. For mobile communication systems operating in a fading environment with frequent periods of low signal-to-noise ratio and the possibility of losses of carrier phase synchronization in the receiver, the invariance to 90 degree ambiguous demodulation should be a significant advantage

New sum rules for nucleon and trinucleon total photoproduction cross-sections

Two new sum rules are derived relating Dirac radii and anomalous magnetic moments of the considered strongly interacting fermions with the convergent integral over a difference of the total proton and neutron, as well as $He^3$ and $H^3$, photoproduction cross-sections.Comment: 1 eps figure. Contribution presented at the PHOTON'03, April 7-11, 2003, Frascati (Roma), Ital

Towards the Standard Model spectrum from elliptic Calabi-Yau

We show that it is possible to construct supersymmetric three-generation models of Standard Model gauge group in the framework of non-simply-connected elliptically fibered Calabi-Yau, without section but with a bi-section. The fibrations on a cover Calabi-Yau, where the model has 6 generations of SU(5) and the bundle is given via the spectral cover description, use a different description of the elliptic fibre which leads to more than one global section. We present two examples of a possible cover Calabi-Yau with a free involution: one is a fibre product of rational elliptic surfaces $dP_9$; another example is an elliptic fibration over a Hirzebruch surface. There we give the necessary amount of chiral matter by turning on in the bundles a further parameter, related to singularities of the fibration and the branching of the spectral cover.Comment: 31 pages, 1 eps-figure, reference added, bundle parameters for dP9 model change

Cantilever-based Resonant Gas Sensors with Integrated Recesses for Localized Sensing Layer Deposition

This work presents mass-sensitive hammerhead resonators with integrated recesses as a gas-phase chemical microsensor platform. Recesses are etched into the head region of the resonator to locally deposit chemically sensitive polymers by ink-jet printing. This permits the sensing films to be confined to areas that (a) are most effective in detecting mass loading and (b) are not strained during the in-plane vibrations of the resonator. As a result of the second point, even 5-μm thick polymer coatings on resonators with a 9-12 μm silicon thickness barely affect the Q-factor in air. This translates into higher frequency stability and ultimately higher sensor resolution compared to uniformly coated devices

Web-Wide Application Customization:The Case of Mashups

Application development of is commonly a balancing of interests, as the question of what should actually be implemented is answered differently by different stakeholders. This paper considers mashups, which are a way of allowing an application to grow beyond the capabilities of the original developers. First, it introduces several approaches to integrate mashups into the services, or Web pages, that they are based upon. These approaches commonly implement ways to determine which mashups are potentially relevant for display in a certain Web page context. One approach, ActiveTags, enables users to create reliable mashups based on tags, which effectively, leads to customized views of Web pages with tagged content. A scenario that demonstrates the potential benefits of this approach is presented. Second, a formalization of the approaches is presented which uses a relational analog to show their commonalities. The abstraction from implementation specifics opens the range of vision for fundamental capabilities and gives a clear picture of future work

Recent tests for the statistical parton distributions

We compare some recent experimental results obtained at DESY, SLAC and Jefferson Lab., with the predictions of the statistical model, we have previously proposed. The result of this comparison is very satisfactory.Comment: 12 pages, 6 eps figures, version to appear in Mod. Phys. Lett.

From Version 1.0 to Version 2.0:A Brief History of the Web

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Rotational Effects of Twisted Light on Atoms Beyond the Paraxial Approximation

The transition probability for the emission of a Bessel photon by an atomic system is calculated within first order perturbation theory. We derive a closed expression for the electromagnetic potentials beyond the paraxial approximation that permits a systematic multipole approximation . The matrix elements between center of mass and internal states are evaluated for some specially relevant cases. This permits to clarify the feasibility of observing the rotational effects of twisted light on atoms predicted by the calculations. It is shown that the probability that the internal state of an atom acquires orbital angular momentum from light is, in general, maximum for an atom located at the axis of a Bessel mode. For a Gaussian packet, the relevant parameter is the ratio of the spread of the atomic center of mass wave packet to the transversal wavelength of the photon.Comment: 10 pages, no figure

Web Service Discovery – Reality Check 2.0

In practice the ability to find the right Web service decides between a functionality being implemented anew and at least the possibility of executing it via a service. This report evaluates existing public portals for Web service discovery with respect to their characteristics and their acceptance by developers. For this, we distinguish different possible settings and use cases and evaluate how these are supported in practice. Only few of the publicly available Web service registries are growing in size and importance, with the use case best supported being the pre-programming phase of evaluation of the service landscape. <br