arXiv subjects

J. Allard

Publications and source records attributed to J. Allard.

4 recordsLinked to original sources

arXiv2023

Visualization of Extremely Sparse Contingency Table by Taxicab Correspondence Analysis: A Case Study of Textual Data

We present an overview of taxicab correspondence analysis, a robust variant of correspondence analysis, for visualization of extremely sparse ontingency tables. In particular we visualize an extremely sparse textual data set of size 590 by 8265 concerning fragments of 8 sacred books recently introduced by Sah and Fokoué (2019) and studied quite in detail by (12 + 1) dimension reduction methods (t-SNE, UMAP, PHATE,...) by Ma, Sun and Zou (2022).

stat.ML↗

arXiv2021

The large inner Micromegas modules for the Atlas Muon Spectrometer Upgrade: construction, quality control and characterization

The steadily increasing luminosity of the LHC requires an upgrade with high-rate and high-resolution detector technology for the inner end cap of the ATLAS muon spectrometer: the New Small Wheels (NSW). In order to achieve the goal of precision tracking at a hit rate of about 15 kHz/cm$^2$ at the inner radius of the NSW, large area Micromegas quadruplets with 100\,\microns spatial resolution per plane have been produced. % IRFU, from the CEA research center of Saclay, is responsible for the production and validation of LM1 Micromegas modules. The construction, production, qualification and validation of the largest Micromegas detectors ever built are reported here. Performance results under cosmic muon characterisation will also be discussed.

physics.ins-det↗

arXiv2020

TCA and TLRA: A comparison on contingency tables and compositional data

There are two popular general approaches for the analysis and visualization of a contingency table and a compositional data set: Correspondence analysis (CA) and log ratio analysis (LRA). LRA includes two independently well developed methods: association models and compositional data analysis. The application of either CA or LRA to a contingency table or to compositional data set includes a preprocessing centering step. In CA the centering step is multiplicative, while in LRA it is log bi-additive. A preprocessed matrix is double-centered, so it is a residuel matrix; which implies that it affects the final results of the analysis. This paper introduces a novel index named the intrinsic measure of the quality of the signs of the residuals (QSR) for the choice of the preprocessing, and consequently of the method. The criterion is based on taxicab singular value decomposition (TSVD) on which the package TaxicabCA in R is developed. We present a minimal R script that can be executed to obtain the numerical results and the maps in this paper. Three relatively small sized data sets available freely on the web are used as examples.

stat.ME↗

arXiv2001

Rejuvenation of the Controls for the CERN PS/Isolde Facilty Using Industrial Components

In the context of the general consolidation of the CERN ISOLDE facility, a project has been started to upgrade the ISOLDE control system. We describe the new ISOLDE control system, emphasizing the systematic use of industrial components such as PLCs and field buses, their integration with the existing, VME based, CERN PS control system and their potential applicability to both existing and new controls problems at the CERN PS complex. We also discuss how to extend a PLC-based solution to the case where real-time response is an issue.

physics.acc-ph↗