A semi-parametric model for circular data based on mixtures of beta distributions

This paper introduces a new, semi-parametric model for circular data, based on mixtures of shifted, scaled, beta (SSB) densities. This model is more general than the Bernstein polynomial density model which is well known to provide good approximations to any density with finite support and it is shown that, as for the Bernstein polynomial model, the trigonometric moments of the SSB mixture model can all be derived. Two methods of fitting the SSB mixture model are considered. Firstly, a classical, maximum likelihood approach for fitting mixtures of a given number of SSB components is introduced. The Bayesian information criterion is then used for model selection. Secondly, a Bayesian approach using Gibbs sampling is considered. In this case, the number of mixture components is selected via an appropriate deviance information criterion. Both approaches are illustrated with real data sets and the results are compared with those obtained using Bernstein polynomials and mixtures of von Mises distributions

- VALUATION EQULIBRIUM REVISITED

This paper extends the notion of valuation equilibrium which applies to market economies involving the choice of a public environment. Unlike some other recent work, it is assumed here that consumers and firms evaluate alternative environments taking market prices as given (hence this notion is closer to that of competitive equilibria). It is shown that valuation equilibria with balanced tax schemas yield eficient allocations and that eficient allocations can be decentralized as valuation equilibria, with tax schemas that may be unbalanced.valuation equilibrium, non-convexities, public goods

EFFICIENCY AND CORE PROPERTIES OF VALUATION EQUILIBRIUM WITH INCREASING RETURNS

This paper considers market economies involving the choice of a public environment when there are nonconvexities in production. It discusses the decentralization of efficient allocations by means of valuation equilibrium, adapting to many private goods the notion due to Mas-Colell (1980) which extends the Lindahlian approach to the pure theory of public goods. It is shown that a valuation equilibrium satisfies the two welfare theorems and is in the core.Valuation Equilibrium, Increasing Returns to Scale, Efficiency.

Optimal randomness certification from one entangled bit

By performing local projective measurements on a two-qubit entangled state one can certify in a device-independent way up to one bit of randomness. We show here that general measurements, defined by positive-operator-valued measures, can certify up to two bits of randomness, which is the optimal amount of randomness that can be certified from an entangled bit. General measurements thus provide an advantage over projective ones for device-independent randomness certification.Comment: 7 pages, 1 figure, computational details at http://nbviewer.ipython.org/github/peterwittek/ipython-notebooks/blob/master/Optimal%20randomness%20generation%20from%20entangled%20quantum%20states.ipyn

On the political economy of income redistribution and crime

A general equilibrium analysis of the effects of income redistribution and crime, showing that while expenditures on police protection reduce crime, it is possible for the crime rate to increase with redistribution.Crime ; Income distribution

Simulation of coalescence, break up and mass transfer in bubble columns by using the Conditional Quadrature Method of Moments in OpenFOAM

The evaluation of the mass transfer rates and the fluid-dynamics aspects of bubble columns are strongly affected by the intrinsic poly-dispersity of the gas phase, namely the different dispersed bubbles are usually distributed over a certain range of size and chemical composition values. In our previous work, gas-liquid systems were investigated by coupling Computational Fluid Dynamics with mono-variate population balance models (PBM) solved by using the quadrature method of moments (QMOM). Since mass transfer rates depend not only on bubble size, but also on bubble composition, the problem was subsequently extended to the solution of multi-variate PBM (Buffo et al. 2013). In this work, the conditional quadrature method of moments (CQMOM) is implemented in the open-source code OpenFOAM for describing bubble coalescence, breakage and mass transfer of a realistic partially aerated rectangular bubble column, experimentally investigated by Diaz et al.(2008). Eventually, the obtained results are here compared with the experimental data availabl