Confinement, deconfinement and the photon propagator in 3D cQED on the lattice

We report on a lattice study of the gauge boson propagator of 3D compact QED in Landau gauge at zero and finite temperature. Non-perturbative effects are reflected by the generation of a mass m and by an anomalous dimension alpha. These effects can be attributed to monopoles and are absent in the propagator of the regular part of the gauge field.Comment: 3 pages, 4 figures, talk presented by A.S. at 5th International Conference on Quark Confinement and the Hadron Spectrum, Gargnano, Italy, 10-14 Sep 200

Prediction of a surface state and a related surface insulator-metal transition for the (100) surface of stochiometric EuO

We calculate the temperature and layer-dependent electronic structure of a 20-layer EuO(100)-film using a combination of first-principles and model calculation based on the ferromagnetic Kondo-lattice model. The results suggest the existence of a EuO(100) surface state which can lead to a surface insulator-metal transition.Comment: 9 pages, 5 figures, Phys. Rev. Lett. (in press

Self-Stabilizing TDMA Algorithms for Dynamic Wireless Ad-hoc Networks

In dynamic wireless ad-hoc networks (DynWANs), autonomous computing devices set up a network for the communication needs of the moment. These networks require the implementation of a medium access control (MAC) layer. We consider MAC protocols for DynWANs that need to be autonomous and robust as well as have high bandwidth utilization, high predictability degree of bandwidth allocation, and low communication delay in the presence of frequent topological changes to the communication network. Recent studies have shown that existing implementations cannot guarantee the necessary satisfaction of these timing requirements. We propose a self-stabilizing MAC algorithm for DynWANs that guarantees a short convergence period, and by that, it can facilitate the satisfaction of severe timing requirements, such as the above. Besides the contribution in the algorithmic front of research, we expect that our proposal can enable quicker adoption by practitioners and faster deployment of DynWANs that are subject changes in the network topology

Merging Automobile Insurance Regulatory Bodies: The Case of Atlantic Canada

The recent automobile liability insurance crisis in Atlantic Canada has prompted the four provincial legislations (Newfoundland and Labrador, New Brunswick, Nova Scotia and Prince Edward Island) to setup a task force to redesign, if necessary, the personal automobile insurance system. After reviewing some of the most interesting new regulatory changes, our paper proposes a new area of discussion: The merger of the four provincial insurance regulatory bodies to combat insurance fraud. We base our paper on the principle that recent premium increases are mainly due to an increase in insurance fraud. We show that merging the regulatory bodies may reduce insurance fraud if the merger allows savings on the average audit cost and on the development of better fraud detection technology. Finally, we suggest a fraud reducing insurance taxation scheme to finance insurance fraud investigations. La récente crise dans le Canada Atlantique au sujet de l'assurance de la responsabilité civile des automobilistes a contraint les gouvernements des quatre provinces (Terre-Neuve et Labrador, Nouveau-Brunswick, Nouvelle-Écosse et l'Île-du-Prince-Édouard) à mettre en place une commission pour étudier la possibilité de réorganiser, si nécessaire, leur système d'assurance automobile. Après avoir analysé les plus intéressantes modifications à la réglementation mises en place dans ces provinces, notre étude offre un nouveau terrain de discussion, soit la fusion des quatre réglementations provinciales afin de combattre la fraude à l'assurance. Notre étude se base sur le principe que les récentes augmentations dans les primes sont attribuables à une augmentation de la fraude à l'assurance dans ces provinces. En fusionnant les réglementations des quatre provinces, nous montrons que la fraude à l'assurance peut diminuer si la fusion permet d'épargner une partie du coût de vérification encouru par les assureurs lors de réclamations douteuses. Également, nous montrons qu'une telle fusion peut permettre de développer une meilleure technologie de vérification des réclamations. Nous terminons le papier en suggérant un système de taxation particulier qui non seulement peut financer les investissements nécessaires pour combattre la fraude, mais peut également réduire la fraude directement.insurance fraud, asymmetric information, insurance taxation, public policy, fraude à l'assurance, information asymétrique, taxation à l'assurance, politique publique

Matter near to the Endpoint of the Electroweak Phase Transition

Wave functions and the screening mass spectrum in the 3D SU(2)-Higgs model near to the phase transition line below the endpoint and in the crossover region are calculated. In the crossover region the changing spectrum versus temperature is examined showing the aftermath of the phase transition at lower Higgs mass. Large sets of operators with various extensions are used allowing to identify wave functions in position space.Comment: 3 pages, 8 figures, LaTex+espcrc2.sty; LATTICE98(electroweak

Merging automobile regulatory bodies: The case of Atlantic Canada

The recent automobile liability insurance crisis in Atlantic Canada has prompted the four provincial legislations (Newfoundland and Labrador, New Brunswick, Nova Scotia and Prince Edward Island) to setup a task force to redesign, if necessary, the personal automobile insurance system. After reviewing some of the most interesting new regulatory changes, our paper proposes a new area of discussion: The merger of the four provincial insurance regulatory bodies to combat insurance fraud. We base our paper on the principle that recent premium increases are mainly due to an increase in insurance fraud. We show that merging the regulatory bodies may reduce insurance fraud if the merger allows savings on the average audit cost and on the development of better fraud detection technology. Finally, we suggest a fraud reducing insurance taxation scheme to finance insurance fraud investigations. --Insurance Fraud,Asymmetric Information,Insurance Taxation,Public Policy

Self-stabilizing TDMA Algorithms for Wireless Ad-hoc Networks without External Reference

Time division multiple access (TDMA) is a method for sharing communication media. In wireless communications, TDMA algorithms often divide the radio time into timeslots of uniform size, $\xi$, and then combine them into frames of uniform size, $\tau$. We consider TDMA algorithms that allocate at least one timeslot in every frame to every node. Given a maximal node degree, $\delta$, and no access to external references for collision detection, time or position, we consider the problem of collision-free self-stabilizing TDMA algorithms that use constant frame size. We demonstrate that this problem has no solution when the frame size is $\tau < \max\{2\delta,\chi_2\}$, where $\chi_2$ is the chromatic number for distance-$2$ vertex coloring. As a complement to this lower bound, we focus on proving the existence of collision-free self-stabilizing TDMA algorithms that use constant frame size of $\tau$. We consider basic settings (no hardware support for collision detection and no prior clock synchronization), and the collision of concurrent transmissions from transmitters that are at most two hops apart. In the context of self-stabilizing systems that have no external reference, we are the first to study this problem (to the best of our knowledge), and use simulations to show convergence even with computation time uncertainties