Ahmed El Alaoui

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One approach to improving the running time of kernel-based machine learning methods is to build a small sketch of the input and use it in lieu of the full kernel matrix in the machine learning task of interest. Here, we describe a version of this approach that comes with running time guarantees as well as improved guarantees on its statistical performance.(More)
One approach to improving the running time of kernel-based methods is to build a small sketch of the kernel matrix and use it in lieu of the full matrix in the machine learning task of interest. Here, we describe a version of this approach that comes with running time guarantees as well as improved guarantees on its statistical performance. By extending the(More)
We propose to measure the Beam Spin Asymmetry (BSA) in Deeply Virtual Compton Scattering (DVCS) off 4 He. The measurements will use a 6 GeV polarized electron beam, a 4 He pressurized gas target, the CLAS and the BoNuS RTPC detectors. The major goal of this proposal is to perform the first fully quantitative investigation of the DVCS reaction off a nuclear(More)
We present new algorithms for computing the log-determinant of symmetric , diagonally dominant matrices. Existing algorithms run with cubic complexity with respect to the size of the matrix in the worst case. Our algorithm computes an approximation of the log-determinant in time near-linear with respect to the number of non-zero entries and with high(More)
Measuring Deeply Virtual Compton Scattering on a neutron target is one of the necessary steps to complete our understanding of the structure of the nucleon in terms of Generalized Parton Distributions (GPDs). DVCS on a neutron target allows to operate a flavor decomposition of the GPDs and plays a complementary role to DVCS on a transversely polarized(More)
The proposed measurements are twofold. First, we propose to measure the multiplicities for several hadron species (π + , π − , π 0 , K + , K − , K 0 s) using both hydrogen and deuterium targets. The goal of these measurements is the control of the fragmentation functions used in the extraction of the individual quark and antiquark contributions to the(More)
We consider the problem of decoding a discrete signal of categorical variables from the observation of several histograms of pooled subsets of it. We present an Approximate Message Passing (AMP) algorithm for recovering the signal in the random dense setting where each observed histogram involves a random subset of entries of size proportional to n. We(More)
Given a weighted graph with N vertices, consider a real-valued regression problem in a semi-supervised setting, where one observes n labeled vertices, and the task is to label the remaining ones. We present a theoretical study of ℓ p-based Laplacian regularization under a d-dimensional geometric random graph model. We provide a variational characterization(More)
We present a search for ten baryon-number violating decay modes of Λ hyperons using the CLAS detector at Jefferson Laboratory. Nine of these decay modes result in a single meson and single lepton in the final state (Λ → mm) and conserve either the sum or the difference of baryon and lepton number (B ± L). The tenth decay mode (Λ → ¯ pπ +) represents a(More)