•Feature Selection (FS) is modelled as a (mixed) integer optimization problem.•To solve this problem, a new FS algorithm (FSA) with short memory is proposed.•This algorithm has been already ...successfully applied to life science data.•New experiments on randomly generated and real biological datasets are reported.•The results are compared w.r.t. other FSA confirming the validity of our approach.
Feature selection methods are used in machine learning and data analysis to select a subset of features that may be successfully used in the construction of a model for the data. These methods are applied under the assumption that often many of the available features are redundant for the purpose of the analysis. In this paper, we focus on a particular method for feature selection in supervised learning problems, based on a linear programming model with integer variables. For the solution of the optimization problem associated with this approach, we propose a novel robust metaheuristics algorithm that relies on a Greedy Randomized Adaptive Search Procedure, extended with the adoption of short memory and a local search strategy. The performances of our heuristic algorithm are successfully compared with those of well-established feature selection methods, both on simulated and real data from biological applications. The obtained results suggest that our method is particularly suited for problems with a very large number of binary or categorical features.
Highlights • Supervised classification of Alzheimer disease patients • A novel technique for feature extraction from magnetic resonance images • Combination of key points spatial position and their ...distribution around the patients brain • Experimental evidence on real biomedical data sets • The method outperforms state-of-the-art approaches in terms of classification performance
The surface Resistive Plate Counter (sRPC) is a revolutionary RPC based on surface resistive electrodes realized with Diamond-Like-Carbon sputtered on Apical® foil. Exploiting high granularity ...current evacuation schemes developed for resistive MPGD and using electrodes with low surface resistivity (down to ∼100MΩ/□), sRPCs standing particle fluxes up to several hundreds kHz/cm2 should be easily developed. The scalability of the technology allows the construction of detectors for large area applications at future high luminosity colliders.
We present a new limit on the production of a light dark-force mediator with the KLOE detector at DAΦNE. This boson, called U, has been searched for in the decay ϕ→ηU, U→e+e−, analyzing the decay ...η→π0π0π0 in a data sample of 1.7 fb−1. No structures are observed in the e+e− invariant mass distribution over the background. This search is combined with a previous result obtained from the decay η→π+π−π0, increasing the sensitivity. We set an upper limit at 90% C.L. on the ratio between the U boson coupling constant and the fine structure constant of α′/α<1.7×10−5 for 30<MU<400 MeV and α′/α⩽8×10−6 for the sub-region 50<MU<210 MeV. This result assumes the Vector Meson Dominance expectations for the ϕηγ⁎ transition form factor. The dependence of this limit on the transition form factor has also been studied.
The surface Resistive Plate Counter (sRPC) is a new RPC based on surface resistive electrodes realized with Diamond-Like-Carbon (DLC) sputtered on Apical\protect \relax \special {t4ht=®} foil. ...Exploiting the high rate resistive MPGD technology, detectors able to stand several tens of kHz/cm2 can be easily developed. The scalability of the technology allows the construction of detectors for large area applications at future high luminosity colliders.
The existence of a light dark force mediator has been tested with the KLOE detector at DAΦNE. This particle, called U, is searched for using the decay chain ϕ→ηU, η→π+π−π0, U→e+e−. No evidence is ...found in 1.5 fb−1 of data. The resulting exclusion plot covers the mass range 5<MU<470 MeV, setting an upper limit on the ratio between the U boson coupling constant and the fine structure constant, α′/α, of ⩽2×10−5 at 90% C.L. for 50<MU<420 MeV.
Performance of μ-RWELL detector vs resistivity of the resistive stage Bencivenni, G.; De Oliveira, R.; Felici, G. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
04/2018, Volume:
886
Journal Article
Peer reviewed
Open access
The μ-RWELL is a compact spark-protected single amplification stage Micro-Pattern-Gaseous-Detector (MPGD). The detector amplification stage is realized with a polyimide structure, micro-patterned ...with a dense matrix of blind-holes, integrated into the readout structure. The anode is formed by a thin Diamond Like Carbon (DLC) resistive layer separated by an insulating glue layer from the readout strips. The introduction of the resistive layer strongly suppressing the transition from streamer to spark gives the possibility to achieve large gains (> 104), without significantly affecting the capability to be efficiently operated in high particle fluxes. In this work we present the results of a systematic study of the μ-RWELL performance as a function of the DLC resistivity. The tests have been performed either with collimated 5.9 keV X-rays or with pion and muon beams at the SPS Secondary Beamline H4 and H8 at CERN.
The existence of a new force beyond the Standard Model is compelling because it could explain several striking astrophysical observations which fail standard interpretations. We searched for the ...light vector mediator of this dark force, the U boson, with the KLOE detector at the DAΦNE e+e− collider. Using an integrated luminosity of 1.54 fb−1, we studied the process e+e−→Uγ, with U→e+e−, using radiative return to search for a resonant peak in the dielectron invariant-mass distribution. We did not find evidence for a signal, and set a 90% CL upper limit on the mixing strength between the Standard Model photon and the dark photon, ε2, at 10−6–10−4 in the 5–520 MeV/c2 mass range.
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