Stable Marriage with Multi-Modal Preferences

We introduce a generalized version of the famous Stable Marriage problem, now based on multi-modal preference lists. The central twist herein is to allow each agent to rank its potentially matching counterparts based on more than one "evaluation mode" (e.g., more than one criterion); thus, each agent is equipped with multiple preference lists, each ranking the counterparts in a possibly different way. We introduce and study three natural concepts of stability, investigate their mutual relations and focus on computational complexity aspects with respect to computing stable matchings in these new scenarios. Mostly encountering computational hardness (NP-hardness), we can also spot few islands of tractability and make a surprising connection to the \textsc{Graph Isomorphism} problem

Time-dependent Fr\"ohlich transformation approach for two-atom entanglement generated by successive passage through a cavity

Time-dependent Fr\"ohlich transformations can be used to derive an effective Hamiltonian for a class of quantum systems with time-dependent perturbations. We use such a transformation for a system with time-dependent atom-photon coupling induced by the classical motion of two atoms in an inhomogeneous electromagnetic field. We calculate the entanglement between the two atoms resulting from their motion through a cavity as a function of their initial position difference and velocity.Comment: 7 pages, 3 figure

Effect of Poisson ratio on cellular structure formation

Mechanically active cells in soft media act as force dipoles. The resulting elastic interactions are long-ranged and favor the formation of strings. We show analytically that due to screening, the effective interaction between strings decays exponentially, with a decay length determined only by geometry. Both for disordered and ordered arrangements of cells, we predict novel phase transitions from paraelastic to ferroelastic and anti-ferroelastic phases as a function of Poisson ratio.Comment: 4 pages, Revtex, 4 Postscript figures include

Posttraumatische Belastungsstörungen in Deutschland: Ergebnisse einer gesamtdeutschen epidemiologischen Untersuchung

Zusammenfassung: In einer repräsentativen Bevölkerungsstichprobe (n=2426) über ein breites Alterspektrum (14-93Jahre) wurden die Prävalenz traumatischer Ereignisse, des Vollbildes der posttraumatische Belastungsstörung (PTBS) und partieller PTBS-Syndrome geschätzt. Ein standardisiertes Interview mit einer Traumaliste des Composite International Diagnostic Interviews (CIDI) und eine PTSD-Symptomliste nach DSM-IV (modifizierte PTSD-Symptomskala) wurden eingesetzt. Die Einmonatsprävalenzrate lag bei 2,3% für das PTBS-Vollbild sowie 2,7% für die partiellen PTBS-Syndrome. Während sich keine Geschlechtsunterschiede hinsichtlich der Prävalenz ergaben, zeigten sich Altersgruppenunterschiede: Die über 60-Jährigen hatten eine Prävalenz bez. des PTBS-Vollbildes von 3,4%, während diese bei den 14- bis 29-Jährigen 1,3% und bei den 30- bis 59-Jährigen 1,9% betrug. Die partiellen PTBS-Syndrome zeigten ebenfalls einen Altersgipfel mit 3,8% in der Gruppe der Älteren sowie 2,4% bei Mittelalten und 1,3% bei jungen Erwachsenen. Die Ergebnisse entsprechen weitgehend denen anderer internationaler Studien, wenn Kriegsauswirkungen für bestimmte Altersgruppen als nationale Besonderheiten berücksichtigt werden. Erstmals konnte unsere repräsentative Studie eine - wahrscheinlich durch den 2.Weltkrieg mitbedingte - relativ hohe Prävalenz der PTBS in der höchsten Altersgruppe der deutschen Bevölkerung aufzeige

Towards a Macroscopic Modelling of the Complexity in Traffic Flow

We present a macroscopic traffic flow model that extends existing fluid-like models by an additional term containing the second derivative of the safe velocity. Two qualitatively different shapes of the safe velocity are explored: a conventional Fermi-type function and a function exhibiting a plateau at intermediate densities. The suggested model shows an extremely rich dynamical behaviour and shows many features found in real-world traffic data.Comment: submitted to Phys. Rev.

Simulation of associative learning with the replaced elements model

Associative learning theories can be categorised according to whether they treat the representation of stimulus compounds in an elemental or configural manner. Since it is clear that a simple elemental approach to stimulus representation is inadequate there have been several attempts to produce more elaborate elemental models. One recent approach, the Replaced Elements Model (Wagner, 2003), reproduces many results that have until recently been uniquely predicted by Pearce’s Configural Theory (Pearce, 1994). Although it is possible to simulate the Replaced Elements Model using “standard” simulation programs the generation of the correct stimulus representation is complex. The current paper describes a method for simulation of the Replaced Elements Model and presents the results of two example simulations that show differential predictions of Replaced Elements and Pearce’s Configural Theor