Evaluation aktiver Arbeitsmarktpolitik - Probleme und Perspektiven : Einführung in das Schwerpunktheft

In dem Beitrag werden zunächst Ansätze und Methoden von Evaluationsstudien beschrieben. Danach werden die Beiträge des Schwerpunktheftes vorgestellt. Diese verdeutlichen die Notwendigkeit der Evaluation aktiver Arbeitsmarktpolitik, diskutieren die damit zusammenhängenden methodischen Probleme, präsentieren Lösungsvorschläge zu diesen Problemen und bringen dem Leser die Thematik anhand empirischer Anwendungen näher. (IAB)Arbeitsmarktpolitik, Wirkungsforschung - Methode

Evaluation aktiver Arbeitsmarktpolitik in Deutschland : eine Einführung

Der Beitrag führt in ein Schwerpunktheft ein, in dem Konzepte und empirische Befunde der Evaluation aktiver Arbeitsmarktpolitik in Deutschland vorgestellt und Zwischenergebnisse aus den laufenden "Hartz-Evaluationen" präsentiert werden. Zunächst wird die Entwicklung der Evaluationsforschung in Deutschland umrissen, dann werden die Beiträge des Heftes kurz beschrieben und ein Zwischenresümee gezogen. (IAB)arbeitsmarktpolitische Maßnahme, Wirkungsforschung

Simulations and plans for possible DLA experiments at SINBAD

In this work we present the outlines of possible experiments for dielectric laser acceleration (DLA) of ultra-short relativistic electron bunches produced by the ARES linac, currently under construction at the SINBAD facility (DESY Hamburg). The experiments are to be performed as part of the Accelerator on a Chip International Program (ACHIP), funded by the Gordon and Betty Moore Foundation. At SINBAD we plan to test the acceleration of already pre-accelerated relativistic electron bunches in laser-illuminated dielectric grating structures. We present outlines of both the acceleration of ultra-short single bunches, as well as the option to accelerate phase-synchronous sub-fs microbunch trains. Here the electron bunch is conditioned prior to the injection by interaction with an external laser field in an undulator. This generates a sinusoidal energy modulation that is transformed into periodic microbunches in a subsequent chicane. The phase synchronization is achieved by driving both the modulation process and the DLA with the same laser pulse. In addition to the conceptual layouts and plans of the experiments we present start-to-end simulation results for different ARES working points.Comment: EAAC'17 conference proceeding

Zielgruppenspezifische Evaluation von Arbeitsbeschaffungsmaßnahmen: Gewinner und Verlierer

"Arbeitsbeschaffungsmaßnahmen (ABM) waren lange Zeit ein wichtiges Instrument aktiver Arbeitsmarktpolitik (AAMP) in Deutschland. Im Zeitraum 2000 bis 2004 nahmen insgesamt knapp 1 Mio. Personen - teils mehrfach - an diesen Maßnahmen teil und es wurden fast 12 Mrd. Euro dafür ausgegeben. Eine umfassende Wirkungsanalyse mit Berücksichtigung von Effektheterogenitäten war bis zur Aufbereitung der prozessproduzierten Daten der Bundesagentur für Arbeit (BA) für wissenschaftliche Untersuchungen aufgrund der unzureichenden Datenlage nicht möglich. Die Verwendung der umfangreichen Kundendaten der BA ermöglicht die wissenschaftliche Evaluation der Wirkungen der Programme der aktiven Arbeitsmarktpolitik; ABM sind das erste Instrument, dessen Wirkungen mit Berücksichtigung zielgruppenspezifischer Unterschiede in den Effekten untersucht werden konnten. In der Studie werden die wichtigsten Ergebnisse der Analysen der ABM-Programme zusammengefasst. Dabei werden die Implikationen für die Arbeitsmarktpolitik auch vor dem Hintergrund der Hartz-Reformen und den damit verbundenen institutionellen Neuerungen diskutiert." (Autorenreferat

Self-organized density patterns of molecular motors in arrays of cytoskeletal filaments

The stationary states of systems with many molecular motors are studied theoretically for uniaxial and centered (aster-like) arrangements of cytoskeletal filaments using Monte Carlo simulations and a two-state model. Mutual exclusion of motors from binding sites of the filaments is taken into account. For small overall motor concentration, the density profiles are exponential and algebraic in uniaxial and centered filament systems, respectively. For uniaxial systems, exclusion leads to the coexistence of regions of high and low densities of bound motors corresponding to motor traffic jams, which grow upon increasing the overall motor concentration. These jams are insensitive to the motor behavior at the end of the filament. In centered systems, traffic jams remain small and an increase in the motor concentration leads to a flattening of the profile, if the motors move inwards, and to the build-up of a concentration maximum in the center of the aster if motors move outwards. In addition to motors density patterns, we also determine the corresponding patterns of the motor current.Comment: 48 pages, 8 figure

Timing and tracking for the Crystal Barrel detector

The aim of the project D.3 is the upgrade of several detector components used in the CBELSA/TAPS experiment at ELSA. The readout of the Crystal Barrel Calorimeter will be extended by a timing branch in order to gain trigger capability for the detector, which will allow to measure completely neutral final states in photoproduction reactions (see projects A.1 and C.5). Additionally, the readout of the inner crystals of the TAPS detector, which covers the forward opening of the Crystal Barrel Calorimeter, will be modified to be capable of high event rates due to the intensity upgrade of ELSA. Furthermore, a full-scale prototype Time Projection Chamber (TPC) has been built to be used as a new central tracker for the CBELSA/TAPS experiment at ELSA and the FOPI experiment at GSI

Development of a GEM-TPC prototype

The use of GEM foils for the amplification stage of a TPC instead of a con- ventional MWPC allows one to bypass the necessity of gating, as the backdrift is suppressed thanks to the asymmetric field configuration. This way, a novel continuously running TPC, which represents one option for the PANDA central tracker, can be realized. A medium sized prototype with a diameter of 300 mm and a length of 600 mm will be tested inside the FOPI spectrometer at GSI using a carbon or lithium beam at intermediate energies (E = 1-3AGeV). This detector test under realistic experimental conditions should allow us to verify the spatial resolution for single tracks and the reconstruction capability for displaced vertexes. A series of physics measurement implying pion beams is scheduled with the FOPI spectrometer together with the GEM-TPC as well.Comment: 5 pages, 4 figures, Proceedings for 11th ICATTP conference in como (italy

The Beaming Pattern of Doppler Boosted Thermal Annihilation Radiation: Application to MeV Blazars

The beaming pattern of thermal annihilation radiation is broader than the beaming pattern produced by isotropic nonthermal electrons and positrons in the jets of radio-emitting active galactic nuclei which Compton scatter photons from an external isotropic radiation field. Thus blueshifted thermal annihilation radiation can provide the dominant contribution to the high-energy radiation spectrum at observing angles theta > 1/Gamma, where Gamma is the bulk Lorentz factor of the outflowing plasma. This effect may account for the spectral features of MeV blazars discovered with the Compton Telescope on the Compton Gamma Ray Observatory. Coordinated gamma-ray observations of annihilation line radiation to infer Doppler factors and VLBI radio observations to measure transverse angular speeds of outflowing plasma blobs can be used to determine the Hubble constant.Comment: 15 pages including 3 figures, requires AAS Latex macros, accepted for publication in The Astrophysical Journa