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On the Stability of Racing Sailing Boats with Foils

第十三届国际体视学大会

作者： Jesus Angulo delphine Reberioux Guillaume Thibault Chantal etievant Fernand Meyer cmm-centre de morphologie mathématique mathématiques et systèmes MINES ParisTechFrance centre de R&D Pierre Fabre Toulouse France

＜正＞High content screening（HCS） refers to technological platforms for parallel cells growing in multi-well plates and fluorescent labelling of proteins of interest,together with image capture by automated microscopy and subsequent cell image *** is of interest for discovery of new cellular biology mechanisms,of new active molecules in pharmacological studies,etc.

关键词： fluorescence microscopy shading correction illumination normalization DNA quantification Parzen-window pdf estimation

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Chinese Annals of mathematics,Series B 2018年第3期39卷 427-450页

作者： Philippe deSTUYNdeR Caroline FABRE Département d'ingénierie mathématique Laboratoire M2N Conservatoire National des Arts et Métiers 292rue saint Martin75003 ParisFrance Laboratoire de mathématiques d'Orsay Univ.Paris-SudCNRSUniversitéParis-Saclay 91405 OrsayFrance

The development of foils for racing boats has changed the strategy of ***,the America's cup held in San Francisco,has been the theatre of a tragicomic history due to the foils. During the last round,the New-Zealand boat was winning by 8 to1 against the defender USA. The winner is the first with 9 victories. USA team understood suddenly(may be) how to use the control of the pitching of the main foils by adjusting the rake in order to stabilize the ship. And USA won by 9 victories against 8 to the challenger NZ. The goal in this paper is to point out few aspects which could be taken into account in order to improve this mysterious control law which is known as the key of the victory of the USA team. There are certainly many reasons and in particular the cleverness of the sailors and of all the engineering team behind this project. But it appears interesting to have a mathematical discussion,even if it is a partial one,on the mechanical behaviour of these extraordinary sailing boats. The numerical examples given here are not the true *** have just been invented in order to explain the theoretical developments concerning three points: The possibility of tacking on the foils for sailing upwind,the nature of foiling instabilities,if there are,when the boat is flying and the control laws.

关键词：不稳定性航行控制轮船旧金山美国法律水手

Assessment of Intra-Seasonal Variability and Trends of Precipitations in a Climate Change Framework in West Africa

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Atmospheric and Climate Sciences 2022年第1期12卷 150-171页

作者： Daniel Bio Tore Adechina Eric Alamou Ezéchiel Obada Eliezer Iboukoun Biao Esdras B. Josué Zandagba Laboratoire de Géosciences de l’Environnement et Applications Université Nationale des Sciences Technologies Ingénierie et Mathématiques (UNSTIM) Abomey Benin Laboratoire d’Hydrologie Appliquée (LHA) Institut National de l’Eau Université d’Abomey-Calavi (UAC) Godomey Benin école Nationale Supérieure des Travaux Publics (ENSTP/UNSTIM) Abomey Benin école Nationale Supérieure de Génie mathématique et Modélisation (ENSGMM/UNSTIM) Abomey Benin

Climate change has led human beings to take an interest in the study of meteorological and climatic phenomena. In fact, the main impact of climate change on different sectors of society is caused by extreme events since the occurrence of extreme events leads to more impact related to change in mean climate. Unfortunately, the West African region is vulnerable to extreme rainfall impact because its economy is based on rain-fed agriculture. This study examined the seasonal variability of extreme rainfall in West Africa. Eight (8) climate indices were chosen from among the 27 defined by the Expert Team on Climate Change detection and Indices (etCCDI). The nonparametric Mann-Kendall test was used to assess the seasonal trends. The indices of the same types (frequency or intensity) were compared to assess the intra-seasonal variation of extreme precipitation. The results indicate that, regardless of the season, the Gulf of Guinea receives more rainfall than the Sahel. This phenomenon is due to the fact that the coastal part of West Africa is under the influence of evaporation which is observed at the Atlantic Ocean and during the monsoon, while the other part is dominated by the desert. Mann-Kendall’s test revealed upward and downward trends during each season. The increase in extreme rainfall trends in the number of consecutive dry days suggests that droughts, due to global warming, could be observed and could have severe consequences in terms of water availability, energy supply, agricultural yields and ecosystems in West Africa. In addition, it can lead to the loss of biodiversity and health issues. It is therefore essential for policymakers or decisions makers to determine strategies and mitigation measures against climate change and its impacts on populations.

关键词： Extreme Precipitation Indices Variability Trend Mann Kendall West Africa

On Problems in the Calculus of Variations in Increasingly Elongated Domains

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Chinese Annals of mathematics,Series B 2018年第2期39卷 163-182页

作者： hervé le dret amira mokrane sorbonne universités upmc univ. paris 06 cnrs laboratoire jacques-louis lionsBoite courrier 18775252 Paris Cedex O5Fance laboratoire d’équations aux dérivées partielles non linéaires et histoire des mathématiques ensB．P．92 Vieux Kouba 16050 Alger Algerie usthb faculté des mathématiques département d’analyse laboratoire d’analyse mathématique et numérique des équations aux dérivées partiellesBab Ezzouar Alger Algerie

This paper deals with minimization problems in the calculus of variations set in a sequence of domains, the size of which tends to infinity in certain directions and such that the data only depend on the coordinates in the directions that remain constant. The authors study the asymptotic behavior of minimizers in various situations and show that they converge in an appropriate sense toward minimizers of a related energy functional in the constant directions.

关键词：演算伸长最小化无穷

deterministic and Stochastic Schistosomiasis Models with General Incidence

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Applied mathematics 2013年第12期4卷 1682-1693页

作者： Stanislas Ouaro Ali Traoré Laboratoire d’Analyse mathématique des Equations (LAME) Unité de Formation et de Recherche en Sciences Exactes et Appliquées Département de Mathématiques Ouagadougou Burkina Faso

In this paper, deterministic and stochastic models for schistosomiasis involving four sub-populations are developed. Conditions are given under which system exhibits thresholds behavior. The disease-free equilibrium is globally asymptotically stable if R0 ?and the unique endemic equilibrium is globally asymptotically stable when R0 >?1. The populations are computationally simulated under various conditions. Comparisons are made between the deterministic and the stochastic model.

关键词： Computational Simulation General Incidence Reproduction Number Schistosomiasis Model Stochastic Differential Equation

Stability Analysis for a Discrete SIR Epidemic Model with delay and General Nonlinear Incidence Function

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Applied mathematics 2018年第9期9卷 1039-1054页

作者： Aboudramane Guiro Dramane Ouedraogo Harouna Ouedraogo Département de mathématiques UFR des Sciences et Techniques Université Nazi Boni de Bobo-Dioulasso & LAboratoire de Mathématique et d’Informatique (LAMI) Bobo-Dioulasso Burkina Faso

In this paper, we construct a backward difference scheme for a class of SIR epidemic model with general incidence f . The step sizeτ used in our discretization is one. The dynamical properties are investigated (positivity and the boundedness of solution). By constructing the Lyapunov function, the general incidence function f must satisfy certain assumptions, under which, we establish the global stability of endemic equilibrium when R0 >1. The global stability of diseases-free equilibrium is also established when R0 ≤1. In addition we present numerical results of the continuous and discrete model of the different class according to the value of basic reproduction number R0.

关键词： Discrete Model delay Lyapunov Functional Nonlinear Incidence Backward Difference Scheme Local Stability Global Stability

A Kaleodoscopic View of Fuzzy Stochastic Optimization*

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American Journal of Operations Research 2021年第6期11卷 283-308页

作者： Yves Tinda Mangongo Justin Dupar Busili Kampempe Monga Kalonda Luhandjula Département de mathématiques et Informatique Université de Kinshasa Kinshasa Democratic Republic of the Congo Département de mathématique-Informatique Université de Kisangani Kisangani Democratic Republic of the Congo

The last three decades have witnessed development of optimization under fuzziness and randomness also called Fuzzy Stochastic Optimization. The main objective of this new field is the need for basing many human decisions on information which is both fuzzily imprecise and probabilistically uncertain. Consistency indexes providing a union nexus between possibilities and probabilities of uncertain events exist in the literature. Nevertheless, there are no reliable transformations between them. This calls for new paradigms for coping with mathematical models involving both fuzziness and randomness. Fuzzy Stochastic Optimization (FSO) is an attempt to fulfill this need. In this paper, we present a panoramic view of Fuzzy Stochastic Optimization emphasizing the methodological aspects. The merits of existing methods are also briefly discussed along with some related theoretical aspects.

关键词： Optimization Randomness Fuzziness Fuzzy Random Variable

Extreme Temperature Trends in the Beninese Niger River Basin (Benin)

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American Journal of Climate Change 2021年第4期10卷 371-385页

作者： Yarou Halissou Alamou Adéchina Eric Obada Ezéchiel Biao Ibukun Eliézer Chaire Internationale de Physique mathématique et Application (CIPMA—CHAIRE UNESCO) Université d’Abomey-Calavi (UAC) Cotonou Benin Laboratoire de Géoscience de l’Environnement et Application (LaGEA/UNSTIM) Abomey Benin Ecole Nationale Supérieure des Travaux Publics (ENSTP) Université Nationale des Sciences Technologies Ingénierie et Mathématiques (UNSTIM) Abomey Benin Ecole Nationale Supérieure de Génie mathématique et Modélisation Université Nationale des Sciences Technologies Ingénierie et Mathématiques (UNSTIM) Abomey Benin

In the context of climate change, the study of the variability of the climatic extremes in several regions of the world is of capital importance. This study has as main objective to analyze the variability of extreme temperature events in the Beninese basin of the Niger River for the recent and the near future. To achieve this objective, seven (07) extreme temperature indices based on historical daily temperature observations (1976 to 2019) and REMO RCM simulation outputs of RCP4.5 and RCP8.5 scenarios (2021-2050) were calculated. The obtained results were represented by calculating the means for each index and analyzing the trends and their significance by the Mann-Kendall method. The results show that the indices of extreme temperature intensity (TNn, TXx, and DTR), and those related to the frequency of warm sequences (WSDI, TN90p and TX90p) have experienced a significant increase in the past. This increase will continue until 2050. In contrast, the cold sequence frequency index (CSDI) decrease over the historical period as well as over the future period. These indices show much more change with the RCP8.5 scenario than with the RCP4.5 of the REMO climate model. Only the TXx and CSDI indices show statistically significant changes at all stations.

关键词： Temperatures Extreme Climatic Variations Beninese Niger River Basin