A stochastic gradient is formulated based on deterministic gradient augmented with Cauchy simulated annealing capable to reach a global minimum with a convergence speed significantly faster when simulated annealing is used alone. In order to solve space-time variant inverse problems known as blind source separation, a novel Helmholtz free energy contrast function, H 1⁄4 E T0S; with imposed ther...

We extend the mixtures of Gaussians (MOG) model to the projected mixture of Gaussians (PMOG) model. In the PMOG model, we assume that q dimensional input data points z(i) are projected by a q dimensional vector w into 1-D variables u(i). The projected variables u(i) are assumed to follow a 1-D MOG model. In the PMOG model, we maximize the likelihood of observing u(i) to find both the model para...

The marginal entropy hðZÞ of a weighted sum of two variables Z 1⁄4 aX þ bY ; expressed as a function of its weights, is a usual cost function for blind source separation (BSS), and more precisely for independent component analysis (ICA). Even if some theoretical investigations were done about the relevance from the BSS point of view of the global minimum of hðZÞ; very little is known about poss...

Most of watermarking techniques are based on Wide Spread Spectrum (WSS). Security of such schemes is studied here in adopting a cryptanalysis point of view. The security is proportional to the difficulty the opponent has to recover the secret parameters, which are, in WSS watermarking scheme, the private carriers. Both theoretical and practical points of view are investigated when several piece...

Independent Component Analysis (ICA) is a statistical signal processing technique whose main applications are blind source separation, blind deconvolution, and feature extraction. Estimation of ICA is usually performed by optimizing a 'contrast' function based on higher-order cumulants. In this paper, it is shown how almost any error function can be used to construct a contrast function to perf...

Real-world data structures are often enhanced with additional pointers capturing alternative paths through a basic inductive skeleton (e.g., back pointers, head pointers). From the static analysis point of view, we must obtain several interlocking shape invariants. At the same time, it is well understood in abstract interpretation design that supporting a separation of concerns is critically im...

It is well known that turnover rates fall with employee tenure and employer size. We document a new empirical fact about turnover: Among surviving employers, separation rates are positively related to industry-level exit rates, even after controlling for tenure and size. Specifically, in a dataset with over 13 million matched employee-employer observations for France, we find that, all else equ...