@incollection{fdi:010084422, title = {{H}oan{K}iem{A}ir : simulating impacts of urban management practices on traffic and air pollution using a tangible agent-based model}, author = {{P}ham {M}inh {D}uc and {C}hapuis, {K}evin and {D}rogoul, {A}lexis and {G}audou, {B}eno{\^i}t and {G}rignard, {A}. and {M}arilleau, {N}icolas and {N}guyen-{H}uu, {T}ri}, editor = {}, language = {{ENG}}, abstract = {{P}edestrian zones are present in numerous cities around the world, and {H}anoi city began to organize one a few years ago. {H}owever, closing roads can lead to heavy traffic congestion in surrounding areas and, consequently, more air pollution in these areas. {T}here is, therefore, a need for analyzing and predicting the outcomes in terms of air pollution when certain roads are closed, before actually implementing a plan. {I}n this project, we used the {GAMA} platform to build an agent-based model that simulates the traffic and air quality in {H}oan {K}iem district. {T}his model can be used as a decision support tool for local authorities and as an information tool for the general public: thanks to its output on a tangible interface, people can interact with the simulation at public venues and explore various scenarios. {A}lthough more accurate data and realistic diffusion models are still lacking and will need further research in the future, the simulation is alreay able to reflect traffic and air pollution peaks during rush hours quite realistically.}, keywords = {{VIET} {NAM} ; {HANOI} ; {HOAN} {KIEM} {LAC}}, booktitle = {2020 {RIVF} {I}nternational {C}onference on {C}omputing and {C}ommunication {T}echnologies ({RIVF})}, numero = {}, pages = {1--7}, address = {{P}iscataway}, publisher = {{IEEE}}, series = {}, year = {2020}, DOI = {10.1109/{RIVF}48685.2020.9140787}, ISBN = {978-1-7281-5378-0}, URL = {https://www.documentation.ird.fr/hor/fdi:010084422}, } @article{fdi:010074405, title = {{P}roceedings of the first {V}ietnamese-{F}rench joint conference on applications of mathematics to ecology, bio-economics, epidemiology and health care : {H}anoi and {T}uanchau, {V}ietnam, december 12-15, 2016}, author = {{D}oanh, {N}. {N}. and {N}guyen-{H}uu, {T}ri}, editor = {}, language = {{ENG}}, abstract = {}, keywords = {}, booktitle = {}, journal = {{A}cta {B}iotheoretica}, volume = {66}, numero = {4}, pages = {255--256}, ISSN = {0001-5342}, year = {2018}, DOI = {10.1007/s10441-018-9337-8}, URL = {https://www.documentation.ird.fr/hor/fdi:010074405}, } @article{fdi:010073796, title = {{C}an overexploited fisheries recover by self-organization ? {R}eallocation of fishing effort as an emergent form of governance}, author = {{B}rochier, {T}imoth{\'e}e and {A}uger, {P}ierre and {T}hiao, {D}. and {B}ah, {A}. and {L}y, {S}. and {N}guyen-{H}uu, {T}ri and {B}rehmer, {P}atrice}, editor = {}, language = {{ENG}}, abstract = {{O}wing to high costs and difficulties in implement control, fisheries are less regulated than terrestrial activities. {I}n areas of weak governance, self-regulation is often the rule. {U}nderstanding the underlying bio-economic mechanisms that drive such fishery systems is crucial for decision making on how to support real fishermen communities. {F}ishing effort reallocation occurs when economic yield drops, suggesting a feedback between fishermen's mobility and local overexploitation. {T}he nature of this feedback is addressed here by using a bio-economic modelling approach applied to a {S}enegalese fishery. {T}he white grouper is a highly valued commercial fish that has suffered intense exploitation in {S}enegal and was predicted to collapse due to a lack of fishery regulation combined with high demand. {S}urprisingly, our analysis of landings and associated price variability suggests that a slow recovery of this fishery is now underway. {M}otivated by this finding, two models were implemented that account for artisanal fishermen's mobility and variable prices. {B}oth models provided the same insight: fishing effort mobility combined with variable fish prices induced a shift from local overexploitation to sub-regional sustainable exploitation. {C}onsidering that fishing effort mobility has steeply increased in recent years, this mechanism might have significantly contributed to the recent observed trends in prices and landings for this fishery. {M}ore generally, these bio-economic models suggest that spatial reallocation of fishing effort acts as emergent governance in under regulated areas that allows, in some cases, the recovery of an overexploited species.}, keywords = {{S}mall scale fisheries ; {S}elf-regulation ; {F}ishing effort ; {B}io-economic model ; {M}igration of fishermen ; {W}est-{A}frica ; {AFRIQUE} {DE} {L}'{OUEST} ; {SENEGAL}}, booktitle = {}, journal = {{M}arine {P}olicy}, volume = {95}, numero = {}, pages = {46--56}, ISSN = {0308-597{X}}, year = {2018}, DOI = {10.1016/j.marpol.2018.06.009}, URL = {https://www.documentation.ird.fr/hor/fdi:010073796}, } @article{fdi:010073670, title = {{ODD}+2{D}: {A}n {ODD} {B}ased {P}rotocol for {M}apping {D}ata to {E}mpirical {ABM}s}, author = {{L}aatabi, {A}. and {M}arilleau, {N}icolas and {N}guyen-{H}uu, {T}ri and {H}bid, {H}. and {B}abram, {M}. {A}.}, editor = {}, language = {{ENG}}, abstract = {{T}he quantity of data and processes used in modeling projects has been dramatically increasing in recent years due to the progress in computation capability and to the popularity of new approaches such as open data. {M}odelers face an increasing difficulty in analyzing and modeling complex systems that consist of many heterogeneous entities. {A}dapting existing models is relevant to avoid dealing with the complexity of writing and studying a new model from scratch. {ODD} ({O}verview, {D}esign concepts, {D}etails) protocol has emerged as a solution to document {A}gent-{B}ased {M}odels ({ABM}s). {I}t appears to be a convenient solution to address significant problems such as comprehension, replication, and dissemination. {H}owever, it lacks a standard that formalizes the use of data in empirical models. {T}his paper tackles this issue by proposing a set of rules that outline the use of empirical data inside an {ABM}. {W}e call this new protocol {ODD}+2{D} ({ODD}+{D}ecision + {D}ata). {ODD}+2{D} integrates a mapping diagramcalled {DAM}ap ({D}ata to {A}gent {M}apping). {T}his mapping model formalizes howdata are processed and mapped to agent-based models. {I}n this paper, we focus on the architecture of {ODD}+2{D}, and we illustrate it with a residential mobility model in {M}arrakesh.}, keywords = {{E}mpirical {A}gent-{B}ased {M}odels ; {ODD} protocol ; {ODD}+2{D} ; {M}apping ; {D}ata analysis ; {S}ocial simulation ; {MAROC} ; {MARRAKECH}}, booktitle = {}, journal = {{JASSS}-the {J}ournal of {A}rtificial {S}ocieties and {S}ocial {S}imulation}, volume = {21}, numero = {2}, pages = {art. 9 [24 p.]}, ISSN = {1460-7425}, year = {2018}, DOI = {10.18564/jasss.3646}, URL = {https://www.documentation.ird.fr/hor/fdi:010073670}, } @article{fdi:010070836, title = {{U}ncertainty in empirical estimates of marine larval connectivity}, author = {{K}aplan, {D}avid and {C}uif, {M}. and {F}auvelot, {C}{\'e}cile and {V}igliola, {L}aurent and {N}guyen-{H}uu, {T}ri and {T}iavouane, {J}. and {L}ett, {C}hristophe}, editor = {}, language = {{ENG}}, abstract = {{D}espite major advances in our capacity to measure marine larval connectivity (i.e. the pattern of transport of marine larvae from spawning to settlement sites) and the importance of these measurements for ecological and management questions, uncertainty in experimental estimates of marine larval connectivity has been given little attention. {W}e review potential uncertainty sources in empirical larval connectivity studies and develop {B}ayesian statistical methods for estimating these uncertainties based on standard techniques in the mark-recapture and genetics literature. {T}hese methods are implemented in an existing {R} package for working with connectivity data, {C}onn{M}at{T}ools, and applied to a number of published connectivity estimates. {W}e find that the small sample size of collected settlers at destination sites is a dominant source of uncertainty in connectivity estimates in many published results. {F}or example, widths of 95% {CI}s for relative connectivity, the value of which is necessarily between 0 and 1, exceeded 0.5 for many published connectivity results, complicating using individual results to conclude that marine populations are relatively closed or open. {T}his "small sample size" uncertainty is significant even for studies with near-exhaustive sampling of spawners and settlers. {T}hough largely ignored in the literature, the magnitude of this uncertainty is straightforward to assess. {B}etter accountability of this and other uncertainties is needed in the future so that marine larval connectivity studies can fulfill their promises of providing important ecological insights and informing management questions (e.g. related to marine protected area network design, and stock structure of exploited organisms). {I}n addition to using the statistical methods developed here, future studies should consistently evaluate and report a small number of critical factors, such as the exhaustivity of spawner and settler sampling, and the mating structure of target species in genetic studies.}, keywords = {connectivity ; larval dispersal ; parentage analysis ; self-recruitment ; transgenerational marking}, booktitle = {}, journal = {{ICES} {J}ournal of {M}arine {S}cience}, volume = {74}, numero = {6}, pages = {1723--1734}, ISSN = {1054-3139}, year = {2017}, DOI = {10.1093/icesjms/fsw182}, URL = {https://www.documentation.ird.fr/hor/fdi:010070836}, } @incollection{fdi:010072196, title = {{F}ormalizing data to agent model mapping using {MOF} : application to a model of residential mobility in {M}arrakesh}, author = {{L}aatabi, {A}. and {M}arilleau, {N}icolas and {N}guyen-{H}uu, {T}ri and {H}bid, {H}. and {B}abram, {M}. {A}.}, editor = {}, language = {{ENG}}, abstract = {{M}odeling and simulating the world with agent-based models is a one of the key disciplines that emerge today in the computing area, with the development of power calculation machines and the availability of huge amount of data. {M}any methodologies have been established to guide the elaboration of different models, but few ones have focused on linking data to model. {I}n this paper, we give a formalized mapping between data and multi-agent components ({DAM}ap: {D}ata to {A}gent {M}apping), as a first step in the process of standardizing the development of a simulation model from raw data. {T}hen we apply it to an household decision-making process in the city of {M}arrakesh.}, keywords = {{MAROC} ; {MARRAKECH}}, booktitle = {{A}gent and multi-agent systems : technology and applications}, numero = {58}, pages = {107--117}, address = {{C}hamp}, publisher = {{S}pringer}, series = {{S}mart {I}nnovation, {S}ystems and {T}echnologies}, year = {2016}, DOI = {10.1007/978-3-319-39883-9_9}, ISBN = {978-3-319-39882-2}, URL = {https://www.documentation.ird.fr/hor/fdi:010072196}, } @inproceedings{fdi:010068010, title = {{M}ulti-site fishery models with price variation depending on demand and supply [r{\'e}sum{\'e}]}, author = {{A}uger, {P}ierre and {L}y, {S}. and {M}ansal, {F}. and {N}guyen {H}uu, {T}ri}, editor = {}, language = {{ENG}}, abstract = {}, keywords = {{AFRIQUE} {DE} {L}'{OUEST} ; {SENEGAL} ; {ATLANTIQUE}}, numero = {}, pages = {44}, booktitle = {{B}ook of abstract international conference {ICAWA} 2014 : the {AWA} project : ecosystem approach to the management of fisheries and the marine environment in {W}est {A}frican waters}, year = {2015}, ISBN = {9782955360201}, URL = {https://www.documentation.ird.fr/hor/fdi:010068010}, } @article{fdi:010062478, title = {{A} mathematical model of a fishery with variable market price : sustainable fishery/over-exploitation}, author = {{M}ansal, {F}. and {N}guyen-{H}uu, {T}ri and {A}uger, {P}ierre and {B}alde, {M}.}, editor = {}, language = {{ENG}}, abstract = {{W}e present a mathematical bioeconomic model of a fishery with a variable price. {T}he model describes the time evolution of the resource, the fishing effort and the price which is assumed to vary with respect to supply and demand. {T}he supply is the instantaneous catch while the demand function is assumed to be a monotone decreasing function of price. {W}e show that a generic market price equation ({MPE}) can be derived and has to be solved to calculate non trivial equilibria of the model. {T}his {MPE} can have 1, 2 or 3 equilibria. {W}e perform the analysis of local and global stability of equilibria. {T}he {MPE} is extended to two cases: an age-structured fish population and a fishery with storage of the resource.}, keywords = {{D}ynamical systems ; {F}ishery ; {V}ariable price ; {M}arket price equation ; {D}emand function ; {E}quilibrium ; {S}tability ; {S}ustainable ; exploitation/overexploitation}, booktitle = {}, journal = {{A}cta {B}iotheoretica}, volume = {62}, numero = {3}, pages = {305--323}, ISSN = {0001-5342}, year = {2014}, DOI = {10.1007/s10441-014-9227-7}, URL = {https://www.documentation.ird.fr/hor/fdi:010062478}, } @article{fdi:010061333, title = {{A} model of a multi-site fishery with variable price : from over-exploitation to sustainable fisheries}, author = {{L}y, {S}. and {M}ansal, {F}. and {B}alde, {M}. and {N}guyen {H}uu, {T}ri and {A}uger, {P}ierre}, editor = {}, language = {{ENG}}, abstract = {{W}e present a mathematical model of a fishery on several sites with a variable price. {T}he model takes into account the evolution during the time of the resource, fishes and boats movements between the different it sites, fishing effort and price that varies with respect to supply and demand. {W}e suppose that boats and fishes movements as well as prices variations occur at a fast time scale. {NW} use methods of aggregation of variables in order to reduce the number of variables and we derive a reduced model governing two global variables, respectively the biomass of the resource and the fishing effort of the whole fishery. {W}e look for the existence of equilibria of the aggregated model. {W}e show that the aggregated model can have {I}, 2 or 3 non trivial equilibria. {W}e show that a variation of the total number of sites can induce a switch from over-exploitation to sustainable fisheries.}, keywords = {dynamical system ; multi-site fishery ; variable price ; demand function ; equilibrium ; stability ; optimum capture}, booktitle = {}, journal = {{M}athematical {M}odelling of {N}atural {P}henomena}, volume = {8}, numero = {6}, pages = {130--142}, ISSN = {0973-5348}, year = {2013}, DOI = {10.1051/mmnp/20138609}, URL = {https://www.documentation.ird.fr/hor/fdi:010061333}, } @article{fdi:010056269, title = {{E}ffects of refuges and density dependent dispersal on interspecific competition dynamics}, author = {{N}guyen-{N}goc, {D}. and {N}guyen-{H}uu, {T}ri and {A}uger, {P}ierre}, editor = {}, language = {{ENG}}, abstract = {}, keywords = {{COMPETITION} {INTERSPECIFIQUE} ; {MODELE} {MATHEMATIQUE} ; {ANALYSE} {STATISTIQUE} ; {DISPERSION} ; {DENSITE} {DE} {POPULATION}}, booktitle = {}, journal = {{I}nternational {J}ournal of {B}ifurcation and {C}haos}, volume = {22}, numero = {2}, pages = {11}, ISSN = {1250-0290}, year = {2012}, DOI = {10.1142/{S}0218127412500290}, URL = {https://www.documentation.ird.fr/hor/fdi:010056269}, } @article{fdi:010055926, title = {{M}odelling herbivore population dynamics in the {A}mboseli {N}ational {P}ark, {K}enya : application of spatial aggregation of variables to derive a master model}, author = {{M}ose, {V}. {N}. and {N}guyen-{H}uu, {T}ri and {A}uger, {P}ierre and {W}estern, {D}.}, editor = {}, language = {{ENG}}, abstract = {{T}he recent expansion of human activities such as agriculture has continuously threatened to block wildlife migration corridors that connect {A}mboseli {N}ational {P}ark ({K}enya) to surrounding ecosystems. {W}e study the impact of blocked corridors on herbivore populations using a spatial mathematical model that describes the movements and population dynamics of selected species (zebra, wildebeest and {G}rant's gazelle) based on resource availability. {A}ggregation methods are used to reduce the complexity of the model which uses actual parameters calibrated from long term data collected in the area for over three decades. {T}he model suggests the need to maintain these connections to sustain species diversity. {O}ur results show that blocked migration corridors lead to competitive exclusion where only one species survives. {H}owever, a possible mechanism of maintenance of biodiversity in the area could be due to an exchange of animals between the park and surrounding ecosystems, when the oscillations of species densities in the ecosystems are out of phase compared to each other and to those within the park.}, keywords = {{L}arge parks ; {H}erbivorous ; {C}ompetition model ; {A}ggregation of variables}, booktitle = {}, journal = {{E}cological {C}omplexity}, volume = {10}, numero = {{SI}}, pages = {42--51}, ISSN = {1476-945{X}}, year = {2012}, DOI = {10.1016/j.ecocom.2012.02.002}, URL = {https://www.documentation.ird.fr/hor/fdi:010055926}, } @article{fdi:010055930, title = {{E}ffects of fast density dependent dispersal on pre-emptive competition dynamics}, author = {{D}oanh, {N}. {N}. and {N}guyen-{H}uu, {T}ri and {A}uger, {P}ierre}, editor = {}, language = {{ENG}}, abstract = {{T}he aim of this work is to investigate the effect of density-dependent dispersal on the outcome of competition in a heterogeneous environment. {W}e present a classical spatial interspecific competition model with two patches connected by fast dispersal. {W}e assume local pre-emptive competition, i.e. on each isolated patch, the species having the largest initial density would exclude the other one. {W}e assume that individuals of species 1 disperse at constant dispersal rates, while species 2 dispersal is density dependent. {S}pecies 2 individuals are more likely to disperse when there are many species 1 competitors in a patch. {W}e investigate if a dispersal strategy that aims at avoiding its competitor can be beneficial. {D}ispersal between patches is assumed to be faster than local population dynamics on each patch. {W}e take advantage of these time scales in order to reduce the complete model into an aggregated model governing total densities of both species at a slow time scale. {T}he analysis of this global model shows that using a density dependent strategy for dispersal is beneficial for species 2 in the sense that it prevents its own extinction and even it allows species 2 to exclude species 1 under some conditions.}, keywords = {{C}ompetition model ; {A}ggregation of variables ; {T}ime scales ; {D}ensity-dependent dispersal ; {E}mergence}, booktitle = {}, journal = {{E}cological {C}omplexity}, volume = {10}, numero = {{SI}}, pages = {26--33}, ISSN = {1476-945{X}}, year = {2012}, DOI = {10.1016/j.ecocom.2011.12.003}, URL = {https://www.documentation.ird.fr/hor/fdi:010055930}, } @article{fdi:010048367, title = {{S}tudy of a virus-bacteria interaction model in a chemostat : application of geometrical singular perturbation theory}, author = {{P}oggiale, {J}. {C}. and {A}uger, {P}ierre and {C}ordoleani, {F}. and {N}guyen-{H}uu, {T}ri}, editor = {}, language = {{ENG}}, abstract = {{T}his paper provides a mathematical analysis of a virus-marine bacteria interaction model. {T}he model is a simplified case of the model published and used by {M}iddelboe ({M}iddelboe, {M}. 2000 {M}icrob. {E}col. 40, 114-124). {I}t takes account of the virus, the susceptible bacteria, the infected bacteria and the substrate in a chemostat. {W}e show that the numerical values of the parameters given by {M}iddelboe allow two different time scales to be considered. {W}e then use the geometrical singular perturbation theory to study the model. {W}e show that there are two invariant submanifolds of dimension two in the four-dimensional phase space and that these manifolds cross themselves on the boundary of the domain of biological relevance. {W}e then perform a rescaling to understand the dynamics in the vicinity of the intersection of the manifolds. {O}ur results are discussed in the marine ecological context.}, keywords = {invariant manifold ; reduction ; singular perturbation ; virus-bacteria interaction}, booktitle = {}, journal = {{P}hilosophical {T}ransactions of the {R}oyal {S}ociety a - {M}athematical {P}hysical and {E}ngineering {S}ciences}, volume = {367}, numero = {1908}, pages = {4685--4697}, ISSN = {1364-503{X}}, year = {2009}, DOI = {10.1098/rsta.2009.0132}, URL = {https://www.documentation.ird.fr/hor/fdi:010048367}, } @article{fdi:010065708, title = {{A}pplications de m{\'e}thodes d'agr{\'e}gation de variables {\`a} l'analyse de mod{\`e}les spatiaux de dynamique des populations}, author = {{N}guyen-{H}uu, {T}ri and {A}uger, {P}ierre}, editor = {}, language = {{FRE}}, abstract = {{L}es mod{\`e}les de dynamique de populations peuvent prendre en compte un nombre important de param{\`e}tres et de variables, ce qui les rend difficiles {\`a} analyser. {L}orsqu'il existe des processus associ{\'e}s {\`a} deux {\'e}chelles de temps diff{\'e}rentes, une lente et une rapide, les m{\'e}thodes d'agr{\'e}gation de variables permettent de construire un mod{\`e}le simplifi{\'e} qui comporte un nombre plus faible de variables. {E}lles permettent ainsi d'analyser et de d{\'e}crire un syst{\`e}me de mani{\`e}re globale. {N}ous pr{\'e}sentons ces m{\'e}thodes dans le cas de mod{\`e}les discrets, puis nous illustrons leur utilisation {\`a} l'aide de mod{\`e}les h{\^o}te-parasito{\¨ie}des spatialis{\'e}s.}, keywords = {{DYNAMIQUE} {DE} {POPULATION} ; {RELATION} {HOTE} {PARASITE} ; {MODELISATION} ; {MODELE} {MATHEMATIQUE} ; {ANALYSE} {MULTIVARIABLE}}, booktitle = {2007 {C}onference in {H}onor of {C}laude {L}obry}, journal = {{A}rima : {R}evue {A}fricaine de la {R}echerche en {I}nformatique et {M}ath{\'e}matiques {A}ppliqu{\'e}es}, volume = {9}, numero = {{N}o sp{\'e}cial {C}laude {L}obry}, pages = {195--210}, ISSN = {1638-5713}, year = {2008}, URL = {https://www.documentation.ird.fr/hor/fdi:010065708}, } @article{PAR00005739, title = {{A}ggregation of variables and applications to population dynamics}, author = {{A}uger, {P}ierre and de la {P}arra, {R}. {B}. and {P}oggiale, {J}. {C}. and {S}anchez, {E}. and {N}guyen-{H}uu, {T}ri}, editor = {}, language = {{ENG}}, abstract = {}, keywords = {}, booktitle = {}, journal = {{S}tructured {P}opulation {M}odels in {B}iology and {E}pidemiology}, volume = {1936}, numero = {}, pages = {209--263}, ISSN = {0075-8434}, year = {2008}, URL = {https://www.documentation.ird.fr/hor/{PAR}00005739}, } @article{fdi:010071081, title = {{P}redator density-dependent prey dispersal in a patchy environment with a refuge for the prey}, author = {{D}uc, {K}. {D}. and {A}uger, {P}ierre and {N}guyen-{H}uu, {T}ri}, editor = {}, language = {{ENG}}, abstract = {{I}n this article, we examine a two-patch predator-prey model which incorporates a refuge for the prey. {W}e suppose that prey migration is dependent on predator density, according to a general function. {W}e consider two different time scales in the dynamics of the model, a fast one describing patch to patch migration, and a slow one involving local prey and predator interaction. {W}e take advantage of the time scales to reduce the dimension of the model by use of methods of aggregation of variables, and thereby examine the effect of predator density-dependent migration of prey on the stability of the predator-prey system. {W}e establish a simple criterion of viability, namely, the existence of a positive and globally stable equilibrium, and show that density dependence has beneficial effects on both species by providing larger equilibrium densities.}, keywords = {}, booktitle = {}, journal = {{S}outh {A}frican {J}ournal of {S}cience}, volume = {104}, numero = {5-6}, pages = {180--184}, ISSN = {0038-2353}, year = {2008}, URL = {https://www.documentation.ird.fr/hor/fdi:010071081}, } @article{PAR00005387, title = {{S}patial synchrony in host-parasitoid models using aggregation of variables}, author = {{N}guyen-{H}uu, {T}ri and {L}ett, {C}hristophe and {A}uger, {P}ierre and {P}oggiale, {J}.{C}.}, editor = {}, language = {{ENG}}, abstract = {}, keywords = {}, booktitle = {}, journal = {{M}athematical {B}iosciences}, volume = {203}, numero = {2}, pages = {204--221}, ISSN = {0025-5564}, year = {2006}, URL = {https://www.documentation.ird.fr/hor/{PAR}00005387}, }