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Construction and Update of an Online Ensemble Score Involving Linear Discriminant Analysis and Logistic Regression

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Applied Mathematics 2022年第2期13卷 228-242页

作者： Benoî t Lalloué jean-marie monnez Eliane Albuisson IECL (Institut Elie Cartan de Lorraine) Inria (Project-Team BIGS) Centre National de la Recherche Scientifique (CNRS) Université de Lorraine Nancy France Inserm U1116 Centre d’Investigation Clinique Plurithématique 1433 Université de Lorraine Nancy France IECL (Institut Elie Cartan de Lorraine) Centre National de la Recherche Scientifique (CNRS) Université de Lorraine Nancy France Délégation à la Recherche Clinique et à l’Innovation(DRCI) CHRU de Nancy Vand&#339 uvre-lès-Nancy France Département Grand-Est de Recherche en Soins Primaires Faculté de Médecine Vand&#339 uvre-lès-Nancy France

The present aim is to update, upon arrival of new learning data, the parameters of a score constructed with an ensemble method involving linear discriminant analysis and logistic regression in an online setting, without the need to store all of the previously obtained data. Poisson bootstrap and stochastic approximation processes were used with online standardized data to avoid numerical explosions, the convergence of which has been established theoretically. This empirical convergence of online ensemble scores to a reference “batch” score was studied on five different datasets from which data streams were simulated, comparing six different processes to construct the online scores. For each score, 50 replications using a total of 10N observations (N being the size of the dataset) were performed to assess the convergence and the stability of the method, computing the mean and standard deviation of a convergence criterion. A complementary study using 100N observations was also performed. All tested processes on all datasets converged after N iterations, except for one process on one dataset. The best processes were averaged processes using online standardized data and a piecewise constant step-size.

关键词： Learning for Big Data Stochastic Approximation Medicine Ensemble Method Online Score

Methodology for Constructing a Short-Term Event Risk Score in Heart Failure Patients

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Applied Mathematics 2018年第8期9卷 954-974页

作者： Kévin Duarte jean-marie monnez Eliane Albuisson CNRS INRIA Institut Elie Cartan de Lorraine Université de Lorraine Nancy France CHRU Nancy INSERM Université de Lorraine CIC Plurithématique Nancy France IUT Nancy-Charlemagne Université de Lorraine Nancy France Institut Elie Cartan de Lorraine Université de Lorraine CNRS Nancy France CHRU Nancy BIOBASE P&ocirc le S2R Université de Lorraine Nancy France Faculté de Médecine InSciDenS Université de Lorraine Nancy France

We present a methodology for constructing a short-term event risk score in heart failure patients from an ensemble predictor, using bootstrap samples, two different classification rules, logistic regression and linear discriminant analysis for mixed data, continuous or categorical, and random selection of explanatory variables to build individual predictors. We define a measure of the importance of each variable in the score and an event risk measure by an odds-ratio. Moreover, we establish a property of linear discriminant analysis for mixed data. This methodology is applied to EPHESUS trial patients on whom biological, clinical and medical history variables were measured.

关键词： Ensemble Predictor Linear Discriminant Analysis Logistic Regression Mixed Data Scoring Supervised Classification

Construction of Parsimonious Event Risk Scores by an Ensemble Method. An Illustration for Short-Term Predictions in Chronic Heart Failure Patients from the GISSI-HF Trial

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Applied Mathematics 2021年第7期12卷 627-653页

作者： Benoî t Lalloué jean-marie monnez Donata Lucci Eliane Albuisson Université de Lorraine CNRS Inria (Project-Team BIGS) IECL (Institut Elie Cartan de Lorraine) Nancy France Inserm U1116 Centre d’Investigation Clinique Plurithématique 1433 Université de Lorraine Nancy France ANMCO Research Center Florence Italy Université de Lorraine CNRS IECL (Institut Elie Cartan de Lorraine) Nancy France DRCI CHRU de Nancy Vand&#339 uvre-lès-Nancy France Faculté de Médecine Département Grand Est de Recherche en Soins Primaires Vand&#339 uvre-lès-Nancy France

Selecting which explanatory variables to include in a given score is a common difficulty, as a balance must be found between statistical fit and practical application. This article presents a methodology for constructing parsimonious event risk scores combining a stepwise selection of variables with ensemble scores obtained by aggregation of several scores, using several classifiers, bootstrap samples and various modalities of random selection of variables. Selection methods based on a probabilistic model can be used to achieve a stepwise selection for a given classifier such as logistic regression, but not directly for an ensemble classifier constructed by aggregation of several classifiers. Three selection methods are proposed in this framework, two involving a backward selection of the variables based on their coefficients in an ensemble score and the third involving a forward selection of the variables maximizing the AUC. The stepwise selection allows constructing a succession of scores, with the practitioner able to choose which score best fits his needs. These three methods are compared in an application to construct parsimonious short-term event risk scores in chronic HF patients, using as event the composite endpoint of death or hospitalization for worsening HF within 180 days of a visit. Focusing on the fastest method, four scores are constructed, yielding out-of-bag AUCs ranging from 0.81 (26 variables) to 0.76 (2 variables).

关键词： Ensemble Score Ensemble Methods Scoring Variable Selection Heart Failure

SesIndexCreatoR:An R Package for Socioeconomic Indices Computation and Visualization

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Open Journal of Statistics 2015年第4期5卷 291-302页

作者： Benoit Lalloue Severine Deguen jean-marie monnez Cindy Padilla Wahida Kihal Denis Zmirou-Navier Nolwenn Le Meur Institut Gustave Roussy ParisFrance EHESP Rennes Sorbonne Paris CiteRennesFrance Inserm UMR IRSETInstitut de recherche sur la sante l’environnement et le travail-1085RennesFrance Lorraine University CNRSINRIA UMR 7502Institut Elie CartanLorraineFrance Lorraine University Medical SchoolLorraineFrance

In order to study social inequalities, indices can be used to summarize the multiple dimensions of the socioeconomic status. As a part of the Equit’Area Project, a public health program focused on social and environmental health inequalities;a statistical procedure to create (neighborhood) socioeconomic indices was developed. This procedure uses successive principal components analyses to select variables and create the index. In order to simplify the application of the procedure for non-specialists, the R package SesIndexCreatoR was created. It allows the creation of the index with all the possible options of the procedure, the classification of the resulting index in categories using several classical methods, the visualization of the results, and the generation of automatic reports.

关键词： Socioeconomic Status Multidimensional Index Principal Component Analysis Hierarchical Classification R

Density Results in Sobolev Spaces Whose Elements Vanish on a Part of the Boundary

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Chinese Annals of Mathematics,Series B 2011年第6期32卷 823-846页

作者： jean-marie Emmanuel BERNARD Laboratoire Analyse et Probabitilités Université d'Evry val d'Essonne23 Boulevard de France91037 EVRYFrance

This paper is devoted to the study of the subspace of Wm＇＂ of functions that vanish on a part γ0 of the boundary. The author gives a crucial estimate of the Poincare constant in balls centered on the boundary of γ0. Then, the convolution-translation method, a variant of the standard mollifier technique, can be used to prove the density of smooth functions that vanish in a neighborhood of γ0, in this subspace. The result is first proved for m = 1, then generalized to the case where m 〉 1, in any dimension, in the framework of Lipschitz-continuous domain. However, as may be expected, it is needed to make additional assumptions on the boundary of γ0, namely that it is locally the graph of some Lipschitz-continuous function.

关键词： Density results Boundary value problems Sobolev spaces

Multiplexing technology for in vitro diagnosis of pathogens： the key contribution of phosphorus dendrimers

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Science China Materials 2018年第11期61卷 1454-1461页

作者： jean Pierre Majoral jean marie Francois Richard Fabre Alice Senescau Serge Mignani Anne-marie Caminade Laboratoire de Chimie de Coordination du CNRS 31077 Toulouse Cedex 4France LCC-CNRS Universit6 de Toulouse CNRSToulouseFrance Dendris 31670 LabegeFrance LISBP UMR CNRS 5504 INRA 79231077 Toulouse Cedex 04France Universite Paris Descartes PRES Sorbonne Paris Cite CNRS-UMR 860Laboratoire de Chimie et de Biochimie Pharmacologiques et Toxicolgique75006 ParisFrance

After the microbiology based on Pasteur's method and polymerase chain reaction(PCR), the diagnosis company named Dendris has proposed a third-generation of diagnosis enabling the search of a broad range of pathogens with strong sensitivity and specificity. This extraordinary profile was possible thanks to the use of phosphorus dendrimers for which various techniques of deposition on a given support were investigated and described and analyzed in this report.

关键词： phosphorus dendrimers diagnosis DNA arrays multiplexing technology

Effects of indole-3-butyric acid and age of stem cuttings on root morphology,growth,and survival of Cornus sericea

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Journal of Forestry Research 2023年第2期34卷 433-440页

作者： Sahari Inoue Chibuzo Ilogu jean-marie Sobze Northern Alberta Institute of Technology Centre for Boreal ResearchPeace RiverAB T8S 1R2Canada Fine Phenotyping Lab Crop Health and ProtectionHarpenden AL52JQUK

Red osier dogwood(Cornus sericea L.),widely distributed throughout North America,is essential for wildlife,thus *** is recommended for reclamation or revegetation of sites disturbed by oil and gas extraction because it tolerates a wide range of soil types and high pH *** germination of this species is extremely difficult with long stratification requirements and poor germination,cuttings facilitate *** this study,to develop techniques to propagate the species from stem cuttings,four concentrations of indole-3-butyric acid(IBA)and two cutting ages previous year’s growth(PYG)and current year’s growth(CYG)were investigated for survival and *** 4 months,survival rate,height growth,and shoot biomass from PYG cuttings were enhanced with IB *** contrast,IB A did not affect these parameters in CYG *** morphology was significantly affected by IB A concentration and cutting ***,at higher concentrations,increased root surface and *** root surface area and length of PYG cuttings were increased,which may facilitate the absorption of essential resources and consequently increase *** results indicate that increasing the concentration of IB A may be an effective way to have better plant survival and growth of previous year’s cuttings in red osier dogwood.

关键词： Vegetative propagation IBA Chronological age Cornus sericea L. Survival rate

Environmental photocatalysis:Perspectives for China

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Science China Chemistry 2010年第9期53卷 1831-1843页

作者： HERRMANN jean marie Institut de Recherches sur la Catalyse et l'Environnement de Lyon UMR 5256 CNRS/Université Lyon1 2 Av.Albert Einstein 69626 Villeurbanne Cedex

Photocatalysis is based on the double aptitude of the photocatalyst(essentially titania) to simultaneously adsorb reactants and absorb efficient *** photocatalysis is able to be efficient in Fine,"Green" and Environmental *** induces mild oxidations in the absence of water by generating active neutral atomic O* *** instance,the oxidation of 4-tert-butyl-toluene is 100% selective in *** water treatment,many toxic inorganic ions are oxidized in their harmless upper oxidized *** elimination of organic pollutants is the main field of water photocatalytic *** of aliphatic and aromatic pollutants are totally mineralized into CO2 and innocuous inorganic *** complex molecules,such as pesticides(herbicides,insecticides,fungicides,etc.) or dyes,are totally *** example of green chemistry is the total degradation of dyes in water,in particular for the azo-dyes,with 100% selective degradation of -N=N-azo-groups into *** is also active in the "bio-world" by killing bacteria(***,streptococcus,etc.) in water without *** pollutants can also be destroyed,especially all the VOC's(volatile organic compounds),providing certain air humidity enabling titania to produce cracking OH* *** chemical engineering reasons,the photocatalyst has to be fixed on a photo-inert *** these conditions,UV-irradiated titania-based photocatalysis could be applied to the elimination of air pollutants,VOC's,solvents,odors,chemicals,*** treatment has to be associated with water and solid waste treatment because of *** is conducted by covering water treatment ponds or lagunas by rafts on which large sheets of Ahlstrom paper are deposited,supporting titania associated with activated ***,virus AH5N2,a model virus close to H5N1,responsible for the avian flu could be totally *** is directly connected wi

关键词： photocatalysis green chemistry environmental chemistry air pollutants water pollutants solar energy China

Synthesis of a novel macrocyclic ligand containing bipyridine units

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Chinese Journal of Chemistry 2000年第3期18卷 384-387页

作者：何永炳 LEHN jean-marie Department of Chemistry Wuhan University Wuhan Hubei 430072 China

The 6-hydroxymethyl-6'-tetrahydropyranyloxymethyl-2, 2'-bipyridine (2) was synthesized by the reaction of 6,6'-dihydroxymethyl-2, 2'-bipyridine (1) with 3, 4-dihydroxypyran (DHP). ***-6'-iodomethyl-2, 2'-bipyridine (5) was obtained from mesylate and iodizating reaction of compound 2. The coupling of 2 and 5 followed by hydrolysis gave bis(6'-hydroxymethyl-2, 2'-bipyridine-6-methyl) ether (7). The macrocyclic ligand 8 was obtained by treating 7 and 6, 6'-dibromethyl-2, 2'-bipyridine. The synthetic conditions of the intermediate 2 and macocyclic ligand 8 were discussed.

关键词： azacrown ether bipyridine derivative macrocyclic ligand