Robust Line Planning in case of Multiple Pools and Disruptions

We consider the line planning problem in public transportation, under a robustness perspective. We present a mechanism for robust line planning in the case of multiple line pools, when the line operators have a different utility function per pool. We conduct an experimental study of our mechanism on both synthetic and real-world data that shows fast convergence to the optimum. We also explore a wide range of scenarios, varying from an arbitrary initial state (to be solved) to small disruptions in a previously optimal solution (to be recovered). Our experiments with the latter scenario show that our mechanism can be used as an online recovery scheme causing the system to re-converge to its optimum extremely fast.Comment: To appear in TAPAS 201

OD Maps for Studying Historical Internal Migration in Ireland

We study internal migration in Ireland, an aspect of migration that is little-studied. OD Maps have enabled us to characterise aspects of spatial patterns in county to county migration more effectively than with other techniques. We found that internal migration is relatively local, but relatively national for Dublin. Although migration increased between 1851 and 1911, there was a decrease in more local migration. This work explores the origins of trends that would continue for over a century and had a profound effect on the population geography of the island

Historical Internal Migration in Ireland

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Will the Patient-Centered Medical Home Transform the Delivery of Health Care?

Explores various definitions of the medical home model, its components, rationale, effect on primary care, issues for implementation such as costs and payment methods, evidence of effectiveness, and healthcare reform provisions promoting it

Electron density and temperature measurements in the exhaust of a mpd source

Electron density and temperature profiles measured in exhaust of magnetoplasma-dynamic sourc

Band gaps in pseudopotential self-consistent GW calculations

For materials which are incorrectly predicted by density functional theory to be metallic, an iterative procedure must be adopted in order to perform GW calculations. In this paper we test two iterative schemes based on the quasi-particle and pseudopotential approximations for a number of inorganic semiconductors whose electronic structures are well known from experiment. Iterating just the quasi-particle energies yields a systematic, but modest overestimate of the band gaps, confirming conclusions drawn earlier for CaB_6 and YH_3. Iterating the quasi-particle wave functions as well gives rise to an imbalance between the Hartree and Fock potentials and results in bandgaps in far poorer agreement with experiment.Comment: 5 pages, 2 figures, 2 table

A Critical Review of the Magnetoplasmadynamic /MPD/ Thrustor for Space Applications

Magnetoplasmadynamic thrustor for space application

General study of superscaling in quasielastic (e,e′)(e,e') and (ν,μ)(\nu,\mu) reactions using the relativistic impulse approximation

The phenomenon of superscaling for quasielastic lepton induced reactions at energies of a few GeV is investigated within the framework of the relativistic impulse approximation. A global analysis of quasielastic inclusive electron and charged-current neutrino scattering reactions on nuclei is presented. Scaling and superscaling properties are shown to emerge from both types of processes. The crucial role played by final state interactions is evaluated by using different approaches. The asymmetric shape presented by the experimental scaling function, with a long tail in the region of positive values of the scaling variable, is reproduced when the interaction in the final state between the knockout nucleon and the residual nucleus is described within the relativistic mean field approach. The impact of gauge ambiguities and off-shell effects in the scaling function is also analyzed.Comment: 34 pages, 14 figures, accepted in Phys. Rev. C. Section II has been shortene

Nonlinear stability and ergodicity of ensemble based Kalman filters

The ensemble Kalman filter (EnKF) and ensemble square root filter (ESRF) are data assimilation methods used to combine high dimensional, nonlinear dynamical models with observed data. Despite their widespread usage in climate science and oil reservoir simulation, very little is known about the long-time behavior of these methods and why they are effective when applied with modest ensemble sizes in large dimensional turbulent dynamical systems. By following the basic principles of energy dissipation and controllability of filters, this paper establishes a simple, systematic and rigorous framework for the nonlinear analysis of EnKF and ESRF with arbitrary ensemble size, focusing on the dynamical properties of boundedness and geometric ergodicity. The time uniform boundedness guarantees that the filter estimate will not diverge to machine infinity in finite time, which is a potential threat for EnKF and ESQF known as the catastrophic filter divergence. Geometric ergodicity ensures in addition that the filter has a unique invariant measure and that initialization errors will dissipate exponentially in time. We establish these results by introducing a natural notion of observable energy dissipation. The time uniform bound is achieved through a simple Lyapunov function argument, this result applies to systems with complete observations and strong kinetic energy dissipation, but also to concrete examples with incomplete observations. With the Lyapunov function argument established, the geometric ergodicity is obtained by verifying the controllability of the filter processes; in particular, such analysis for ESQF relies on a careful multivariate perturbation analysis of the covariance eigen-structure.Comment: 38 page