Simplice Dossou-Gbété | Université De Pau Et Des Pays De L'adour (original) (raw)

Papers by Simplice Dossou-Gbété

HAL (Le Centre pour la Communication Scientifique Directe), 2010

Springer eBooks, 2013

Over the years, the range of applications of mathematics has been progressively enhanced and appl... more Over the years, the range of applications of mathematics has been progressively enhanced and applied mathematics, modeling, and simulation have taken an increasing role. This motivated the French Department of Education to launch a Diploma in applied mathematics at the master’s level 30 years ago. The two first examples of such programs were created in different contexts, one in Paris, one in Pau, a smaller provincial town. These programs have evolved according to the European implementation of the Bologna process; they have taken into account the new range of applications, for instance in Finance, and profited from the spectacular development of computer science.

*INRA, Station d'Hydrobiologie, Ecologie des Poissons, Saint Pee sur Nivelle Diffusion du doc... more *INRA, Station d'Hydrobiologie, Ecologie des Poissons, Saint Pee sur Nivelle Diffusion du document : INRA, Station d'Hydrobiologie, Ecologie des Poissons, Saint Pee sur NivelleNational audienc

Urban Ecosystems, 2020

Setting up a survey may be very complex, especially when no previous data are available on the po... more Setting up a survey may be very complex, especially when no previous data are available on the population of interest. Survey results must be non debatable (i.e. whose results are not open to question and cannot be interpreted in different ways) and precise enough to allow to answer the initial research question. A probabilistic sampling design with sufficient samples for acceptable precision and robust conclusions is then a legitimate sampling strategy. This study objective is to set up an efficient survey of Aedes albopictus on a newly colonized French city where no data are available yet. Following a method we previously published, we use a virtual ecology approach to select the most cost-efficient sampling design with appropriate sample size. This implies modelling an Aedes albopictus population based on another actual population data and testing sampling strategies on this virtual population. This allows us recommending a sampling procedure on this city to achieve precise estimates of tiger mosquitoes probability of presence.

Journal of Applied Geophysics, 2015

$Research paper thumbnail of Natural Microfractures in Quartz Grains: A New Tool to Evaluate Maximum Paleo Effective Stress and Overpressure Onset in Sandstone Reservoirs$

Le Centre pour la Communication Scientifique Directe - HAL - Inria, Jun 1, 2018

This paper deals with the supervised classification when the response variable is binary and its ... more This paper deals with the supervised classification when the response variable is binary and its class distribution is unbalanced. In such situation, it is not possible to build a powerful classifier by using standard methods such as logistic regression, classification tree, discriminant analysis, etc. To overcome this shortcoming of these methods that provide classifiers with low sensibility, we tackled the classification problem here through an approach based on the association rules learning because this approach has the advantage of allowing the identification of the patterns that are well correlated with the target class. Association rules learning is a well known method in the area of data-mining. It is used when dealing with large database for unsupervised discovery of local patterns that expresses hidden relationships between variables. In considering association rules from a supervised learning point of view, a relevant set of weak classifiers is obtained from which one derives a classification rule that performs well.

Journal of Applied Statistics, 2016

ABSTRACT This study is concerned with the extension of the Mallows–Bradley–Terry ranking model fo... more ABSTRACT This study is concerned with the extension of the Mallows–Bradley–Terry ranking model for one block comparison consisting of all the items of interest to situations which allow an expression of no preference. We consider a modification of the Mallows–Bradley–Terry ranking model by introducing an additional parameter, called an index of discrimination, in the model. This permits ties in the model. The maximum likelihood estimates of the parameters are found using a Maximization–Minimization algorithm: the evaluation of the mathematical expectations involved in the log-likelihood equation is obtained by generating samples of Monte Carlo Markov chain from the stationary distribution. In addition, a simulation study for asymptotic properties assessment has been made. The proposed method is applied to analyze data election.

In this paper, we introduce the class of seasonal ARFIMA models with bilinear GARCH (BL-GARCH) ty... more In this paper, we introduce the class of seasonal ARFIMA models with bilinear GARCH (BL-GARCH) type innovations that are capable of capturing simultaneously four key properties of non-linear time series: long range dependence, seasonality, volatility clustering and leverage effects. Stationarity and invertibility conditions are derived and conditional sum of squares (CSS) estimation of the model is also considered. Under some assumptions, we show that the resulting estimators are consistent and asymptotically normally distributed. Monte carlo simulation results are presented to evaluate the small-sample performance of the CSS method for various models.

Behavioral Ecology and Sociobiology, 2014

ABSTRACT The emergence of an animal’s personality is the result of interactions between genetics,... more ABSTRACT The emergence of an animal’s personality is the result of interactions between genetics, environment and experience. It is known that individuals are able to modulate their behaviour according to the context or the social environment. Many studies have shown for example, that familiarity among conspecifics diminishes aggressiveness, although little is known about the underlying processes. Nevertheless, personality traits have long been determined while ignoring the social context, especially in lower vertebrates such as fish. In the present experiment, we hypothesize that group connections (network density) may be positively correlated to consistency of aggressiveness by avoiding over-aggressive acts in further encounters. To test this hypothesis, we used eels (Anguilla anguilla) as a model species and monitored both aggressiveness and sociability in 64 individuals over their first 7 months of growth from the glass eel stage. As expected, social fish were less aggressive than their non-social counterparts at all times, highlighting the existence of a behavioural syndrome in eels. Additionally, rank-order consistency of aggressiveness was higher in groups of fish with high social connectivity, compared to those in less-connected fish groups. While aggressiveness must be consistent to be considered a personality trait, our results suggest that both aggressiveness and its consistency are influenced by initial social context.

Annales de la faculté des sciences de Toulouse Mathématiques, 2002

Biplots for matched two-way tables (*) SIMPLICE DOSSOU-GBÉTÉ (1), AXEL GRORUD (2) Annales de la F... more Biplots for matched two-way tables (*) SIMPLICE DOSSOU-GBÉTÉ (1), AXEL GRORUD (2) Annales de la Faculte des Sciences de Toulouse Vol. XI, n° 4, 2002 pp. 469-483 RESUME.-Cet article a pour objet l'analyse exploratoire de tableaux apparies a deux entrees et leur representation par des « biplots ». Ce faisant, nous revoyons la decomposition en valeurs singulieres des matrices reelles et complexes. 11 est montre comment des methodes classiques, initialement introduites pour analyser des tableaux carres, s'etendent a ce cadre plus general. L'interpretation en terme de modele de ces « biplots » est aussi tiree au clair. ABSTRACT.-This paper is an investigation into the exploratory analyses of matched two-way tables and their biplot visualizations. In doing so, we revisit the singular value decomposition of real and complex matrices. It is shown how standard methods, initially derived for the analysis of square tables, extend to this more general setting. The modeling interpretation of these biplots is also elicited. (*) > Recu le 18 septembre 2001, accepte le 18 septembre 2002

Journal of Mathematics Research, 2012

The class of elliptical structures includes a vast field of known symmetric distributions and cop... more The class of elliptical structures includes a vast field of known symmetric distributions and copulas. This article investigates the properties of the copula underlying a stochastic elliptical process in conditional context. Specifically we characterize the conditional high dimensional copulas of the elliptical process both in non-spatial framework and for space-varying models. A spatial conditional measure is constructed to model the joint dependence of these copulas and distributions with applications to the three most known elliptical structures.

PLoS ONE, 2013

Objective: We sought to identify predictors of in-hospital maternal mortality among women attendi... more Objective: We sought to identify predictors of in-hospital maternal mortality among women attending referral hospitals in Mali and Senegal. Methods: We conducted a cross-sectional epidemiological survey using data from a cluster randomized controlled trial (QUARITE trial) in 46 referral hospitals in Mali and Senegal, during the pre-intervention period of the trial (from October 1st 2007 to October 1st 2008). We included 89,518 women who delivered in the 46 hospitals during this period. Data were collected on women's characteristics, obstetric complications, and vital status until the hospital discharge. We developed a tree-like classification rule (classification rule) to identify patient subgroups at high risk of maternal in-hospital mortality. Results: Our analyses confirm that patients with uterine rupture, hemorrhage or prolonged/obstructed labor, and those who have an emergency ante-partum cesarean delivery have an increased risk of in-hospital mortality, especially if they are referred from another health facility. Twenty relevant patterns, based on fourteen predictors variables, are used to predict in-hospital maternal mortality with 81.41% sensitivity (95% CI = [77.12%-87.70%]) and 81.6% specificity (95% CI = [81.16%-82.02%]). Conclusion: The proposed class association rule method will help health care professionals in referral hospitals in Mali and Senegal to identify mothers at high risk of in-hospital death, and can provide scientific evidence on which to base their decisions to manage patients delivering in their health facilities.

SSRN Electronic Journal, 2019

OBJECTIVE: Air pollution is now a public health concern and there is an urgent need to find local... more OBJECTIVE: Air pollution is now a public health concern and there is an urgent need to find local feasible solution to overcome the related health issues. Regarding outdoor air pollution effect on vendors health and workplaces exposed to high traffic, it is important to accurately define the most exposed between those working along main roads or in roundabouts with high traffic. The purpose of this study was to assess the vendors respiratory health risks associated with these different geographical positions in Cotonou. METHODS: A cross-sectional study was conducted and included all the shops along a main road and a roundabout with high traffic in Cotonou. One person was recruited per shop and was allocated a unique GPS data associated with the geographical position of its shop. Validated questionnaire on respiratory symptoms was administered to 194 individuals who were included. RESULTS: The mean (standard deviation) of age of workers was 36.26 (±11.65) years and the sex ratio (M/F) was 1.8. Most of respondents (69.07%) worked in non-ventilated rooms. 72.68% of the workers reported at least one respiratory symptom. This proportion was significantly different (p<0.001) between the subpopulations at roundabout (96.15%) and apart from the roundabout (64.08%). The most reported symptoms by the workers were respectively cough (47.94%), itchy nose (42.27%) and breathlessness (28.35%). The risk of cough and itchy nose symptoms were respectively 5.15 (OR=5.15; 95% CI= [2.21;12.04]; p< .001) and 3.44 (OR=3.44; 95% CI= [1.55;7.63]; p=0.002) higher in individuals working at the roundabout compared to those working along the main road. CONCLUSION: Working in roundabout is associated with more respiratory disorders than practicing in shop along a main road. In a resources limited settings, it may be important to focus air pollution mitigation effort on this subpopulation of workers.