Research Axis “Data Science, Digital Transformation, Risks & Complex Systems”, with its three distinct yet interconnected topics, signifies the profound efforts of ESILV and EMLV researchers in contributing to a more informed and technologically advanced world.
The first focal point, Complex Systems, is centered on modeling the intricate interactions of various entities. This includes:
Moreover, the realm of Complex Systems extends its reach to personalized recommendations. It seeks to understand the mechanisms behind tailored suggestions and their effects, along with examining factors that influence engagement and sway decision-making.
The Risks domain focuses on the multifaceted aspects of potential threats and challenges:
Lastly, researchers in this domain study economic design, aiming to understand the structures of economies, and how social change interplays with these designs.
The third segment, Data Science and Digital Transformation, is a nod to our evolving digital era:
Nzamba Bignoumba; Nédra Mellouli; Sadok Ben Yahia
A new efficient ALignment-driven Neural Network for Mortality Prediction from Irregular Multivariate Time Series data Journal Article
In: Expert Systems With Applications, vol. 238, no. Part E, pp. 122148, 2024.
@article{bignoumba_2463,
title = {A new efficient ALignment-driven Neural Network for Mortality Prediction from Irregular Multivariate Time Series data},
author = {Nzamba Bignoumba and Nédra Mellouli and Sadok Ben Yahia},
url = {https://www.sciencedirect.com/science/article/pii/S0957417423026507?via%3Dihub},
year = {2024},
date = {2024-03-01},
journal = {Expert Systems With Applications},
volume = {238},
number = {Part E},
pages = {122148},
abstract = {The irregularity of the time interval between observations in and across the stream is a key factor that leads to a drop in performance when classical machine learning or deep learning models are used for a downstream task requiring multivariate time series. Indeed, irregular multivariate time series not only increase the rate of missing values but also lead to data sparsity, which consequently makes the data almost unleverageable and/or ineffective for models. To tackle this scorching challenge, most of the pioneering approaches apply imputation or interpolation in their core, which might lead to embedding data with noise. To especially address this irregular multivariate time series issue, we introduce, in this paper, a new deep neural network model called ALignment-driven Neural Network. The innovative idea of our model is to transform the irregular multivariate time series into pseudo-aligned (or pseudo-regular) latent values. The latter are shown as a matrix, where the coefficients are the latent values of each feature at user-defined reference time points that are evenly spaced. They are obtained through a duplication process driven by an exponential decay mechanism. The obtained output is then passed to a Recurrent Neural Network model, which is undoubtedly the must-use model for regular time series data. To show that our model added value, we looked at the Intensive Care Unit mortality prediction task. In this unit, the physiological measurements used to make decisions have a problem with time irregularity. Leveraging the publicly available MIMIC-III, we compare the performance of our model to that of flagship models. In addition, we also performed extensive ablation studies to highlight the importance of specific components in our model. Interestingly enough, whenever data is collected 24 and 48 h after a patient's admission, we outperform our pioneering competitors, i.e., +1.1% and +1.5% for the AUC score, +2.3% and for the AUPRC score and +0.6% and +1.7%
for the F1-score.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Mofdi El-Amrani; Anouar Obbadi; Mohammed Seaid; Driss Yakoubi
Error estimates for a viscosity-splitting scheme in time applied to non-Newtonian fluid flows Journal Article
In: Computer Methods In Applied Mechanics And Engineering, vol. 419, no. Feb. 2024, pp. 116639, 2024.
@article{el-amrani_2513,
title = {Error estimates for a viscosity-splitting scheme in time applied to non-Newtonian fluid flows},
author = {Mofdi El-Amrani and Anouar Obbadi and Mohammed Seaid and Driss Yakoubi},
url = {https://www.sciencedirect.com/science/article/pii/S0045782523007636?dgcid=coauthor},
year = {2024},
date = {2024-02-01},
journal = {Computer Methods In Applied Mechanics And Engineering},
volume = {419},
number = {Feb. 2024},
pages = {116639},
abstract = {A time fractional-step method is presented for numerical solutions of the incompressible non-Newtonian fluids for which the viscosity is non-linear depending on the shear-rate magnitude according to a generic model. The method belongs to a class of viscosity-splitting procedures and it consists of separating the convection term and incompressibility constraint into two time steps. Unlike the conventional projection methods, the viscosity is not dropped in the last step allowing to enforce the full original boundary conditions on the end-of-step velocity which eliminates any concerns about the numerical boundary layers. We carry out a rigorous error analysis and provide a full first-order error estimate for both the velocity and pressure solutions in the relevant norms. Numerical results are presented for two test examples of non-
Newtonian fluid flows to demonstrate the theoretical analysis and confirm the reliability of this viscosity-splitting scheme.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Youssef Belhamadia; Jean Deteix; Basma Jaffal-Moutarda; Driss Yakoubi
Existence and uniqueness for a convective phase change model with temperature-dependent viscosity Journal Article
In: Journal Of Mathematical Analysis And Applications, vol. 527, no. 2, pp. 127559, 2023.
@article{belhamadia_2366,
title = {Existence and uniqueness for a convective phase change model with temperature-dependent viscosity},
author = {Youssef Belhamadia and Jean Deteix and Basma Jaffal-Moutarda and Driss Yakoubi},
url = {https://www.sciencedirect.com/science/article/pii/S0022247X23005620?via%3Dihub},
year = {2023},
date = {2023-11-01},
journal = {Journal Of Mathematical Analysis And Applications},
volume = {527},
number = {2},
pages = {127559},
abstract = {In this article, we consider a class of phase change model with temperature-dependent viscosity, convection and mixed boundary conditions on a bounded domain that reflect melting and solidification in a variety of real-world applications, such as metal casting and crystal growth. The mathematical model, which is based on the enthalpy formulation, takes into consideration the thermophysical differences between the liquid and solid states. The moving liquid-solid interface is explicitly fulfilled as the energy and momentum equations are solved over the full physical domain. Under particular assumptions, we derive various a priori estimates and prove well-posedness results. Numerical simulation of the model employed in the
paper is presented as an illustration of an example of a melting problem.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Hajer Kefi; Ekatarina Besson; Yue Zhao; Sali FARRAN
Toward Museum Transformation: From Mediation to Social Media-tion and Fostering Omni-visit Experience Journal Article
In: Information & Management, vol. Available online 14 November 2023, 10389, no. Available, pp. Available online 14 November 2023, 10389, 2023.
@article{kefi_2503,
title = {Toward Museum Transformation: From Mediation to Social Media-tion and Fostering Omni-visit Experience},
author = {Hajer Kefi and Ekatarina Besson and Yue Zhao and Sali FARRAN},
url = {https://www.sciencedirect.com/science/article/pii/S0378720623001386},
year = {2023},
date = {2023-11-01},
journal = {Information & Management},
volume = {Available online 14 November 2023, 10389},
number = {Available},
pages = {Available online 14 November 2023, 10389},
abstract = {This article investigates the role played by Information and Communications Technology (ICT) and specifically social media in reshaping the mediation (?Kulturvermittlung') processes enacted by museums along with their digital transformation. We apply a multi-methods research design, including qualitative research conducted within a selection of museums in France, an intercept study at Le Louvre Museum (Paris, France) and finally an online survey. Our findings concurrently put forward the concept of social mediation and illustrate the changing role of museum mediation processes that imply the transformation of visitor experience from a receptive format (consuming informative and entertaining content) to an interactive and collaborative format, through the use of social media and other ICT tools deployed and used complementarily to fulfill visitors needs and gratifications and foster what we call the visitor ?omni-visit experience'. Both theoretical and managerial implications are considered.},
keywords = {},
pubstate = {online},
tppubtype = {article}
}
Etienne Bernard; Francesco Salvarani
On the Homogenization of the Renewal Equation with Heterogeneous External Constraints Journal Article
In: Acta Applicandae Mathematicae, vol. 187, no. 1, pp. 4, 2023.
@article{bernard_2401,
title = {On the Homogenization of the Renewal Equation with Heterogeneous External Constraints},
author = {Etienne Bernard and Francesco Salvarani},
url = {https://link.springer.com/article/10.1007/s10440-023-00594-2},
year = {2023},
date = {2023-10-01},
journal = {Acta Applicandae Mathematicae},
volume = {187},
number = {1},
pages = {4},
abstract = {We study the homogenization limit of the renewal equation with heterogeneous external con- straints by means of the two-scale convergence theory. We prove that the homogenized limit satisfies an equation involving non-local terms, which are the consequence of the oscillations in the birth and death terms. We have moreover shown that the numerical approximation of the homogenized equation via the two-scale limit gives an alternative way for the numerical study of the solution of the limiting problem.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Loubna Salhi; Mohammed Seaid; Driss Yakoubi
Convergence analysis of a class of iterative methods for propagation of reaction fronts in porous media Journal Article
In: Computer Methods In Applied Mechanics And Engineering, vol. 418, no. Part A, pp. 116524, 2023.
@article{salhi_2456,
title = {Convergence analysis of a class of iterative methods for propagation of reaction fronts in porous media},
author = {Loubna Salhi and Mohammed Seaid and Driss Yakoubi},
url = {https://www.sciencedirect.com/science/article/pii/S0045782523006485?dgcid=author},
year = {2023},
date = {2023-10-01},
journal = {Computer Methods In Applied Mechanics And Engineering},
volume = {418},
number = {Part A},
pages = {116524},
abstract = {We present an iterative scheme for the numerical analysis of propagating reaction front problems in porous media satisfying an Arrhenius-type law. The governing equations consist of the Darcy equations for the pressure and flow field coupled to two convection-diffusion-reaction equations for the temperature and depth of conversion.
Well-posedness, existence and uniqueness of the weak solution are first studied using a fixed-point approach and then, analysis of the proposed iterative scheme is investigated. Numerical results are also presented in order
to validate the theoretical estimates and to illustrate the performance of the proposed scheme.
The obtained results are in line with our expectations for a good numerical resolution with high accuracy and stability behaviors.},
keywords = {},
pubstate = {accepted},
tppubtype = {article}
}
Erik Ernesto Vazquez Hernandez; Reto Felix; Lorena Siliceo
Female advertising models and their body mass index (BMI): How does BMI similarity affect perceived product quality? Journal Article
In: Journal Of Consumer Behaviour, vol. 74, no. 10, pp. 1002, 2023.
@article{vazquez_hernandez_2473,
title = {Female advertising models and their body mass index (BMI): How does BMI similarity affect perceived product quality?},
author = {Erik Ernesto Vazquez Hernandez and Reto Felix and Lorena Siliceo},
url = {https://onlinelibrary.wiley.com/doi/10.1002/cb.2274},
year = {2023},
date = {2023-10-01},
journal = {Journal Of Consumer Behaviour},
volume = {74},
number = {10},
pages = {1002},
abstract = {Recent research has pointed out the importance of appearance similarity as a special instance of homophily. The current paper introduces body mass index (BMI) similarity as a convenient and powerful proxy of perceived appearance homophily in the context of female advertising models by showing process evidence and boundary conditions for the effect of BMI similarity on marketing-relevant downstream variables. Study 1 tests how BMI similarity relates to a traditional measure of appearance homophily and perceived reliability of a female advertising model. Study 2 shows that BMI similarity influences perceived product quality and purchase intention. Website vividness negatively moderates the relationship between BMI similarity and product quality. Study 3 tests for alternative explanations and provides support for the mediating effect of appearance homophily for the relationship between BMI similarity and perceived product quality. The findings provide marketing managers with important insights on how to increase their marketing effectiveness by integrating BMI similarity into their marketing communications. Additionally, using BMI similarity serves as an alternative way to promote diversity and inclusion of models with plus-size body type often sought by societal brands.},
keywords = {},
pubstate = {online},
tppubtype = {article}
}
Guillaume Bernis; Matthieu Garcin; Simone Scotti; Carlo Sgarra
Interest rates term structure models driven by Hawkes processes Journal Article
In: Siam Journal On Financial Mathematics, vol. 14, no. 4, pp. 1062-1079, 2023.
@article{bernis_2476,
title = {Interest rates term structure models driven by Hawkes processes},
author = {Guillaume Bernis and Matthieu Garcin and Simone Scotti and Carlo Sgarra},
url = {https://epubs.siam.org/doi/10.1137/22M1502604},
year = {2023},
date = {2023-10-01},
journal = {Siam Journal On Financial Mathematics},
volume = {14},
number = {4},
pages = {1062-1079},
abstract = {This paper includes a marked Hawkes process in the original HJM set-up, and investigates the impact of this assumption on the pricing of the popular vanilla fixed-income derivatives.
Our model exhibits a smile that can fit the implied volatility of swaptions for a given key rate (tenor). We harness on the log-normality of the model, conditionally with respect to jumps, and derive formulae to evaluate both caplets/floorlets and swaptions. Our model exhibits negative jumps on the zero-coupon (hence positive on the rates). Therefore, its behaviour is compatible with the situation where globally low interest rates can suddenly show cluster of positive jumps in case of tensions on the market. One of the main difficulties when dealing with the HJM model is to keep a framework that is Markovian. In particular, it is important to preserve the important features of the Hull and White version, especially the reconstruction formula that provides the zero-coupon bonds in terms of the underlying model factors. In our case, this formula is based on two factors: a classical Gaussian part and a pure jump martingale part based on a Hawkes process.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Matthieu Garcin; Jules Klein; Sana Laaribi
Estimation of time-varying kernel densities and chronology of the impact of COVID-19 on financial markets Journal Article
In: Journal Of Applied Statistics, vol. not yet available, no. not yet av, pp. not yet available, 2023.
@article{garcin_2477,
title = {Estimation of time-varying kernel densities and chronology of the impact of COVID-19 on financial markets},
author = {Matthieu Garcin and Jules Klein and Sana Laaribi},
url = {https://www.tandfonline.com/doi/abs/10.1080/02664763.2023.2272226},
year = {2023},
date = {2023-10-01},
journal = {Journal Of Applied Statistics},
volume = {not yet available},
number = {not yet av},
pages = {not yet available},
abstract = {The time-varying kernel density estimation relies on two free parameters: the bandwidth and the discount factor. We propose to select these parameters so as to minimize a criterion consistent with the traditional requirements of the validation of a probability density forecast. These requirements are both the uniformity and the independence of the so-called probability integral transforms, which are the forecast time-varying cumulated distributions applied to the observations. We thus build a new numerical criterion incorporating both the uniformity and independence properties by the mean of an adapted Kolmogorov-Smirnov statistic. We apply this method to financial markets during the onset of the COVID-19 crisis. We determine the time-varying density of daily price returns of several stock indices and, using various divergence statistics, we are able to describe the chronology of the crisis as well as regional disparities. For instance, we observe a more limited impact of COVID-19 on financial markets in China, a strong impact in the US, and a slow recovery in Europe.},
keywords = {},
pubstate = {online},
tppubtype = {article}
}
Youcef Amirat; Kamel Hamdache
Homogenization of ferrofluid flow models in porous media with Langevin magnetization law Journal Article
In: Journal Of Mathematical Analysis And Applications, vol. 525, no. 1, pp. 127129, 2023.
@article{amirat_2247,
title = {Homogenization of ferrofluid flow models in porous media with Langevin magnetization law},
author = {Youcef Amirat and Kamel Hamdache},
url = {https://www.sciencedirect.com/science/article/pii/S0022247X23001324?via%3Dihub},
year = {2023},
date = {2023-09-01},
journal = {Journal Of Mathematical Analysis And Applications},
volume = {525},
number = {1},
pages = {127129},
abstract = {The paper is concerned with the homogenization of the equations describing the flow of a ferrofluid through a heterogeneous porous medium ? in the presence of an applied magnetic field. We discuss two models where the magnetization M is parallel to the magnetic field H. In the first one M and H satisfy the relation M=?01?fH in ?, where ?0 is a positive constant and 1?f is the characteristic function of ?f (the pore space). In the second model, M and H satisfy the Langevin magnetization law M=MsL(b1|H|)|H|1?fH, where L is the Langevin function given by L(x)=1tanh?x?1x, Ms is the saturation magnetization and b1 is a positive physical constant. The velocity and the pressure satisfy the Stokes equation with a Kelvin magnetic force. We perform the homogenization of the equations of each of the two models. Using the two-scale convergence method, we rigorously derive the homogenized equation for the magnetic potential and determine the asymptotic limit of the magnetization. Then we rigorously derive a Darcy law.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
André Fortin; Driss Yakoubi
High accuracy breaking point detection for stiff DDEs Journal Article
In: Applied Mathematics Letters, vol. 143, pp. 108665, 2023.
@article{fortin_2280,
title = {High accuracy breaking point detection for stiff DDEs},
author = {André Fortin and Driss Yakoubi},
url = {https://www.sciencedirect.com/science/article/abs/pii/S0893965923000976#d1e179},
year = {2023},
date = {2023-09-01},
journal = {Applied Mathematics Letters},
volume = {143},
pages = {108665},
abstract = {We have recently introduced a very high order Discontinuous Galerkin (DG) method for the solution of stiff ordinary differential equations (ODEs) and delay differential equations (DDEs). In this communication we focus on the detection of breaking points frequently arising in the solution of stiff DDEs. Breaking points are discontinuities appearing in the solution of DDEs and/or in some of its derivatives. Breaking points affect the efficiency of the numerical method by forcing very small time steps in their vicinity. They also locally affect the solution accuracy. We therefore introduce a very simple breaking point detection algorithm in order to further improve the efficiency our DG method.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Francesco Salvarani; Etienne Bernard
Homogenization of the linear Boltzmann equation with a highly oscillating scattering term in extended phase space Journal Article
In: Applied Mathematics Letters, vol. 143, pp. 108672, 2023.
@article{salvarani_2286,
title = {Homogenization of the linear Boltzmann equation with a highly oscillating scattering term in extended phase space},
author = {Francesco Salvarani and Etienne Bernard},
url = {https://doi.org/10.1016/j.aml.2023.108672},
year = {2023},
date = {2023-09-01},
journal = {Applied Mathematics Letters},
volume = {143},
pages = {108672},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Erik Ernesto Vazquez Hernandez; Chirag Patel; Salvador Alvidrez; Lorena Siliceo
Images, reviews, and purchase intention on social commerce: The role of mental imagery vividness, cognitive and affective social presence Journal Article
In: Journal Of Retailing And Consumer Services, vol. 74, pp. 103415, 2023.
@article{vazquez_hernandez_2341,
title = {Images, reviews, and purchase intention on social commerce: The role of mental imagery vividness, cognitive and affective social presence},
author = {Erik Ernesto Vazquez Hernandez and Chirag Patel and Salvador Alvidrez and Lorena Siliceo},
url = {https://www.sciencedirect.com/science/article/abs/pii/S0969698923001625?via%3Dihub},
year = {2023},
date = {2023-09-01},
journal = {Journal Of Retailing And Consumer Services},
volume = {74},
pages = {103415},
abstract = {Images and textual reviews are central to social commerce sites. But little is known about the mechanism by which image quality and type of textual review (with personal experiences versus facts) impact consumer purchase intention on a social commerce page. We address this knowledge gap and use the stimulus-organism-response (S-O-R) framework to develop our conceptual framework. We hypothesize that image quality and type of textual review impact purchase intention through imagery vividness that functions as a stimulus. Further, imagery vividness impacts purchase intention positively in the social commerce context through social presence. Specifically, the effect of imagery vividness on purchase intention is likely to be serially mediated by cognitive social presence and affective social presence. We collect data by conducting two experiments using a social media post regarding fashion apparel for middle-aged women on Instagram and find support for our thesis.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Juvert Njeck Sama; Alessandro Biancalani; Alberto Bottino; I Chavdarovski; Daniele Del Sarto; A Ghizzo; Thomas Hayward-Schneider; Philipp Lauber; B Rettino; Francesco Vannini
Effect of temperature anisotropy on the dynamics of geodesic acoustic modes Journal Article
In: Journal Of Plasma Physics, vol. 89, no. 1, pp. 905890109, 2023.
@article{sama_2301,
title = {Effect of temperature anisotropy on the dynamics of geodesic acoustic modes},
author = {Juvert Njeck Sama and Alessandro Biancalani and Alberto Bottino and I Chavdarovski and Daniele Del Sarto and A Ghizzo and Thomas Hayward-Schneider and Philipp Lauber and B Rettino and Francesco Vannini},
url = {https://www.cambridge.org/core/journals/journal-of-plasma-physics/article/abs/effect-of-temperature-anisotropy-on-the-dynamics-of-geodesic-acoustic-modes/B3084D49F9505CDF3AA53221EE074E46},
year = {2023},
date = {2023-08-01},
journal = {Journal Of Plasma Physics},
volume = {89},
number = {1},
pages = {905890109},
abstract = {In this work, we revisit the linear gyro-kinetic theory of geodesic acoustic modes (GAMs) and derive a general dispersion relation for an arbitrary equilibrium distribution function of ions. A bi-Maxwellian distribution of ions is then used to study the effects of ion temperature anisotropy on GAM frequency and growth rate. We find that ion temperature anisotropy yields sensible modifications to both the GAM frequency and growth rate as both tend to increase with anisotropy and these results are strongly affected by the electron to ion temperature ratio.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Driss Yakoubi
Enhancing the viscosity-splitting method to solve the time-dependent Navier-Stokes equations Journal Article
In: Communications In Nonlinear Science And Numerical Simulation, vol. 123, pp. 107264, 2023.
@article{yakoubi_2302,
title = {Enhancing the viscosity-splitting method to solve the time-dependent Navier-Stokes equations},
author = {Driss Yakoubi},
url = {https://www.sciencedirect.com/science/article/abs/pii/S100757042300182X},
year = {2023},
date = {2023-08-01},
journal = {Communications In Nonlinear Science And Numerical Simulation},
volume = {123},
pages = {107264},
abstract = {The viscosity-splitting (VS) scheme for solving the incompressible time-dependent Navier-Stokes equations consists to decouple the full problem into two easy subproblems to resolve.
This method splits the nonlinearity (convection term) and the incompressibility into two different steps. As a result, every subproblem is easier to solve than the Navier-Stokes system. The semi-implicit approach is mostly used in the first step for the nonlinearity term and the intermediate velocity is calculated by dropping the pressure gradient. We then resolve a linear Stokes problem in the next step.
We present a modified viscosity-splitting scheme (Incremental viscosity-splitting) (IVS) to improve this method. This scheme adds the gradient of the pressure (calculated at the previous time step) in the first step and modifies the Stokes equations in the second step to
predict a better value of the intermediate velocity. A manufactured solution and two well-known benchmarks will be used to demonstrate the effectiveness of the suggested strategy.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Frédérique Charles; Annamaria Massimini; Francesco Salvarani
Mathematical and numerical study of a kinetic model describing the evolution of planetary rings Journal Article
In: Computers & Mathematics With Applications, vol. 143, pp. 48-56, 2023.
@article{charles_2316,
title = {Mathematical and numerical study of a kinetic model describing the evolution of planetary rings},
author = {Frédérique Charles and Annamaria Massimini and Francesco Salvarani},
url = {https://www.sciencedirect.com/science/article/pii/S0898122123001724},
year = {2023},
date = {2023-08-01},
journal = {Computers & Mathematics With Applications},
volume = {143},
pages = {48-56},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Nesrine Waga; Hichem Kallel; Nédra Mellouli
Analytical and Deep Learning Approaches for Solving the Inverse kinematic Problem of a High Degrees of Freedom Robotic Arm Journal Article
In: Engineering Applications Of Artificial Intelligence, vol. 123, no. Part B, pp. 106301, 2023.
@article{waga_2351,
title = {Analytical and Deep Learning Approaches for Solving the Inverse kinematic Problem of a High Degrees of Freedom Robotic Arm},
author = {Nesrine Waga and Hichem Kallel and Nédra Mellouli},
url = {https://www.sciencedirect.com/science/article/pii/S0952197623004852?via%3Dihub},
year = {2023},
date = {2023-08-01},
journal = {Engineering Applications Of Artificial Intelligence},
volume = {123},
number = {Part B},
pages = {106301},
abstract = {Inverse kinematics is the basis for controlling the motion of robotic manipulators. It defines the required joint variables for the robotic end-effector accurately reach the desired location. Due to the derivation difficulty, computation complexity, singularity problem, and redundancy, analytical Inverse kinematics solutions pose numerous challenges to the operation of many robotic arms, especially for a manipulator with a high degree of freedom. This paper develops different Deep Learning networks for solving the Inverse kinematics problem of six- Degrees of Freedom robotic manipulators. The implemented neural architectures are Artificial Neural Network, Convolutional Neural Network, Long-Short Term Memory, Gated Recurrent Unit, and Bidirectional Long-Short Term Memory. In this context, we associate the proposed results with a specific tuning of Deep Learning network hyper-parameters (number of hidden layers, learning rate, Loss function, optimization algorithm, number of epochs, etc.). The Bidirectional Long-Short Term Memory network outperformed all proposed architectures. To be close as possible to the experimental results, we have included two types of noise in the training data set to validate which of the five proposed neural networks is more efficient. Furthermore, in this study, we compare the performance of analytical and soft computing solutions in generating robots' trajectories. We include this scenario, focusing on the advantage of implementing neural networks in avoiding the singularity problem that can occur using the analytical approach. In addition, we used the RoboDK simulator to show simulation results with real-world meaning. The performance of Deep Learning models depends on the complexity of the posed problem. Moreover, the complexity of the Inverse Kinematics problem is related to the number of Degrees of Freedom. At the end of this work, we evaluate the influence of the complexity of robotic manipulators on the proposed Deep Learning networks' performance. The results show that the implemented Deep Learning mechanisms performed well in reaching the desired pose of the end-effector. The proposed inverse kinematics strategies apply to other manipulators with different numbers of Degrees of Freedom.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Hanen Balti; Ali Ben Abbes; Yanfang Sang; Nédra Mellouli; Imed Riadh Faraha
Spatio-temporal Heterogeneous Graph using Multivariate Earth Observation Time Series: Application for drought forecasting Journal Article
In: Computers & Geosciences, vol. 179, no. october 20, pp. 105435, 2023.
@article{balti_2397,
title = {Spatio-temporal Heterogeneous Graph using Multivariate Earth Observation Time Series: Application for drought forecasting},
author = {Hanen Balti and Ali Ben Abbes and Yanfang Sang and Nédra Mellouli and Imed Riadh Faraha},
url = {https://www.sciencedirect.com/science/article/pii/S0098300423001395?via%3Dihub},
year = {2023},
date = {2023-08-01},
journal = {Computers & Geosciences},
volume = {179},
number = {october 20},
pages = {105435},
note = {Accurate forecasting is required for the effective risk management of drought disasters. Many machine learning- and deep learning-based models have been proposed for drought forecasting, however, they cannot handle the temporal and/or spatial dependencies in the input data, causing unexpected forecasting results. In order to solve the challenging issue, in this paper we proposed the Heterogeneous Spatio-Temporal Graph (HetSPGraph), for drought forecasting. It includes three major layers: spatial aggregations including inter and intra aggregations, temporal aggregation, and a forecasting network. The main function of HetSPGraph is to learn the dynamic spatiotemporal correlations between the regions and to further predict the drought in different regions, based on which accurate drought forecasting can be achieved. Experimental forecasting results of the Standardized Precipitation Evapotranspiration Index (SPEI) in China indicated that the HetSPGraph model outperformed the traditional baseline methods including the Long Short-Term Memory model (LSTM), Convolutional Neural Network-LSTM (CNN-LSTM), Gated Recurrent Unit (GRU), Spatio-Temporal Graph Convolutional Networks (STGCN) and Geographic-Semantic-Temporal Hypergraph Convolutional Network (GST-HCN). Even for long-term forecasting (12 months), more accurate forecasting results, with the coefficient of determination
higher than 0.89, can also be obtained by HetSPGraph compared to the other three models. The proposed HetSPGraph model has the potential for wider use in forecasting drought and other natural disasters.},
keywords = {},
pubstate = {online},
tppubtype = {article}
}
Raafat Talhouk; Luc Molinet; Ibtissame Zaiter
On well-posedness for some Korteweg-de Vries type equations with variable coefficients Journal Article
In: Journal Of Evolution Equations, vol. 23, no. 3, pp. 52, 2023.
@article{talhouk_2369,
title = {On well-posedness for some Korteweg-de Vries type equations with variable coefficients},
author = {Raafat Talhouk and Luc Molinet and Ibtissame Zaiter},
url = {https://doi.org/10.1007/s00028-023-00904-z},
year = {2023},
date = {2023-07-01},
journal = {Journal Of Evolution Equations},
volume = {23},
number = {3},
pages = {52},
abstract = {In this paper, KdV-type equations with time- and space-dependent coefficients are considered. Assuming that the dispersion coefficient in front of uxxx is positive and uniformly bounded away from zero and that a primitive function of the ratio between the anti-dissipation and the dispersion coefficients is bounded from below, we prove the existence and uniqueness of a solution u such that hu belongs to a classical Sobolev space, where h is a function related to this ratio. The LWP in Hs(R), s > 1/2, in the classical (Hadamard) sense is also proven under this time an assumption of boundedness of the above primitive function. Our approach combines a change of unknown with dispersive estimates. Note that previous results were restricted to Hs(R), s > 3/2, and only used the dispersion to compensate the anti-dissipation and not to lower the Sobolev index required for well-posedness.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Kamel Hamdache; Djamila Hamroun
The Bloch-Torrey limit of a kinetic transport system Journal Article
In: Mediterranean Journal Of Mathematics, vol. 20, no. 3, pp. 122, 2023.
@article{hamdache_2246,
title = {The Bloch-Torrey limit of a kinetic transport system},
author = {Kamel Hamdache and Djamila Hamroun},
url = {https://link.springer.com/article/10.1007/s00009-023-02328-y#citeas},
year = {2023},
date = {2023-06-01},
journal = {Mediterranean Journal Of Mathematics},
volume = {20},
number = {3},
pages = {122},
abstract = {This work is devoted to highlighting the diffusion of some models of Kinetic-Bloch system by an asymptotic analysis. The limit of the kinetic equation when using the classical diffusion scaling shows that the magnetization field becomes parallel to the magnetic field. For the limit of the magnetization when we use a second scaling of the kinetic equation, we show that the dynamics of the magnetization is driven by the Bloch-Torrey diffusion equation.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Chaima Bousbia; Yasmina Daikh; Sarra Maarouf; Driss Yakoubi
Augmented spectral formulation for the Stokes problem with variable viscosity and mixed boundary conditions Journal Article
In: Calcolo, vol. 60, no. 3, pp. 36, 2023.
@article{bousbia_2353,
title = {Augmented spectral formulation for the Stokes problem with variable viscosity and mixed boundary conditions},
author = {Chaima Bousbia and Yasmina Daikh and Sarra Maarouf and Driss Yakoubi},
url = {https://link.springer.com/article/10.1007/s10092-023-00530-8},
year = {2023},
date = {2023-06-01},
journal = {Calcolo},
volume = {60},
number = {3},
pages = {36},
abstract = {This paper deals with the analysis of a new augmented formulation in terms of vorticity, velocity and pressure for the Stokes equations with variable viscosity and mixed boundary conditions. The well-posedness of the continuous problem holds under assumptions on the viscosity. When the domain is a parallelepiped, the spectral discretization is proposed using the Galerkin method with numerical integration. Then, we prove the well-posedness of the obtained discrete problem under the same type of conditions on the viscosity. A priori error estimates is then derived for the three
unknowns. Finally, numerical experiments are presented that confirm the interest of
the discretization.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Fakhrielddine Bader; Mostafa Bendahmane; Mazen Saad; Raafat Talhouk
In: Asymptotic Analysis, vol. 132, no. 3-4, pp. 575-606, 2023.
@article{bader_1995,
title = {Microscopic tridomain model of electrical activity in the heart with dynamical gap junctions. Part 2 - Derivation of the macroscopic tridomain model by unfolding homogenization method},
author = {Fakhrielddine Bader and Mostafa Bendahmane and Mazen Saad and Raafat Talhouk},
url = {https://doi.org/10.3233/ASY-221804},
year = {2023},
date = {2023-05-01},
journal = {Asymptotic Analysis},
volume = {132},
number = {3-4},
pages = {575-606},
abstract = {We study the homogenization of a novel microscopic tridomain system, allowing
for a more detailed analysis of the properties of cardiac conduction than the classical bidomain
and monodomain models. In [5], we detail this model in which gap junctions are considered
as the connections between adjacent cells in cardiac muscle and could serve as alternative
or supporting pathways for cell-to-cell electrical signal propagation. Departing from this mi-
croscopic cellular model, we apply the periodic unfolding method to derive the macroscopic
tridomain model. Several diculties prevent the application of unfolding homogenization
results, including the degenerate temporal structure of the tridomain equations and a nonlin-
ear dynamic boundary condition on the cellular membrane. To prove the convergence of the
nonlinear terms, especially those dened on the microscopic interface, we use the boundary
unfolding operator and a Kolmogorov-Riesz compactness's result.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Jad Dabaghi; Virginie Ehrlacher; Christoph Strossner
Tensor approximation of the self-diffusion matrix of tagged particle processes Journal Article
In: Journal Of Computational Physics, vol. 480, pp. 112017, 2023.
@article{dabaghi_2223,
title = {Tensor approximation of the self-diffusion matrix of tagged particle processes},
author = {Jad Dabaghi and Virginie Ehrlacher and Christoph Strossner},
url = {https://www.sciencedirect.com/science/article/pii/S0021999123001122},
year = {2023},
date = {2023-05-01},
journal = {Journal Of Computational Physics},
volume = {480},
pages = {112017},
abstract = {The objective of this paper is to investigate a new numerical method for the approximation of the self-diffusion matrix of a tagged particle process defined on a grid. While standard numerical methods make use of long-time averages of empirical means of deviations of some stochastic processes, and are thus subject to statistical noise, we propose here a tensor method in order to compute an approximation of the solution of a high-dimensional quadratic optimization problem, which enables to obtain a numerical approximation of the self-diffusion matrix. The tensor method we use here relies on an iterative scheme which builds low-rank approximations of the quantity of interest and on a carefully tuned variance reduction method so as to evaluate the various terms arising in the functional to minimize. In particular, we numerically observe here that it is much less subject to statistical noise than classical approaches.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Daniel Maar; Hajer Kefi; Mehmet A. Orhan
Should brands foster their Instagram account followers' fear of missing out by posting ephemeral content? Journal Article
In: Recherche et Application en Marketing, 2023.
@article{maar_2324,
title = {Should brands foster their Instagram account followers' fear of missing out by posting ephemeral content?},
author = {Daniel Maar and Hajer Kefi and Mehmet A. Orhan},
url = {https://journals.sagepub.com/doi/10.1177/20515707231161808},
year = {2023},
date = {2023-05-01},
journal = {Recherche et Application en Marketing},
abstract = {Several blogs and websites with a focus on social media marketing suggest that brands can benefit from fostering their Instagram account followers' fear of missing out (FoMO) by posting ephemeral content. Relying on an online survey with 550 followers of Instagram brand accounts and a scenario-based experiment with 535 participants, this article shows that content ephemerality triggers followers' FoMO, which increases brand account engagement and brand account fatigue. Brand account engagement (fatigue), in turn, positively (negatively) relates to brand attitude and brand attachment. Further analyses reveal that the total effect of followers' FoMO on brand attachment is positive and significant, while the total effect of FoMO on brand attitude is not significant. Moreover, content ephemerality has a negative and significant total effect on brand attitude. A key implication of these findings is that it is not beneficial for brands to foster their Instagram account followers' FoMO by posting ephemeral content.},
keywords = {},
pubstate = {online},
tppubtype = {article}
}
André Fortin; Driss Yakoubi
A very high order discontinuous Galerkin method for the numerical solution of stiff DDEs Journal Article
In: Applied Mathematics And Computation, vol. 443, pp. 127767, 2023.
@article{fortin_2076,
title = {A very high order discontinuous Galerkin method for the numerical solution of stiff DDEs},
author = {André Fortin and Driss Yakoubi},
url = {https://www.sciencedirect.com/science/article/pii/S0096300322008359},
year = {2023},
date = {2023-04-01},
journal = {Applied Mathematics And Computation},
volume = {443},
pages = {127767},
abstract = {We present a high order discontinuous Galerkin (DG) method for the numerical solution of systems of delay differential equations (DDEs). The method is based on Legendre orthogonal polynomials of high degree k (typically k=10) in each subinterval and is a generalisation to DDEs of a similar method which proved to be very efficient for ordinary differential equations (ODEs). We show how the error can be estimated allowing to control the size of the time step. We also propose a particularly efficient quasi Newton method for the solution of the resulting non linear systems based on a very accurate approximation of the Jacobian matrix that is very easy to implement and with excellent convergence properties. The method is then applied to very stiff systems of DDEs.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Oussama Boussoufa; Yasmina Daikh; Driss Yakoubi
Numerical analysis for backward Euler spectral discretization for Stokes equations with boundary conditions involving the pressure: part I Journal Article
In: Calcolo, vol. 60, no. 2, pp. 1–27, 2023.
@article{boussoufa_2305,
title = {Numerical analysis for backward Euler spectral discretization for Stokes equations with boundary conditions involving the pressure: part I},
author = {Oussama Boussoufa and Yasmina Daikh and Driss Yakoubi},
url = {https://link.springer.com/article/10.1007/s10092-023-00520-w},
year = {2023},
date = {2023-04-01},
journal = {Calcolo},
volume = {60},
number = {2},
pages = {1--27},
abstract = {In this paper, we address the study of the time-dependent Stokes system with boundary conditions involving the pressure. We obtain existence and uniqueness for a classof Lipschitz-continuous domains. Next, a spectral discretizations of the problem is
proposed combined with the backward Euler scheme. The discrete spaces are defined in a way to give exactly divergence-free discrete approximations for the velocity. Then, we prove the associated discrete inf-sup condition and derive a priori error estimates.
Finally, some numerical experiments are presented},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Alexey Mishchenko; Alessandro Biancalani; Juvert Njeck Sama; Alberto Bottino; Sergio Briguglio; M Borchardt; Emanuele Poli; Remi Dumont; Jorge Ferreira; J P Graves; Ralf Kleiber; B Rettino; Thomas Hayward-Schneider; Axel Koenies; Emmanuel Lanti; Philipp Lauber; H Leyh; Zhixin Lu; Hinrich Luetjens; Ben McMillan; Martin Campos Pinto; Baruch Rofman; Christoph Slaby; Francesco Vannini; Laurent Villard; Gregorio Vlad; Xin Wang; Fabien Widmer; Fulvio Zonca
Numerical tools for burning plasmas Journal Article
In: Plasma Physics And Controlled Fusion, vol. 65, no. 6, pp. 064001, 2023.
@article{mishchenko_2378,
title = {Numerical tools for burning plasmas},
author = {Alexey Mishchenko and Alessandro Biancalani and Juvert Njeck Sama and Alberto Bottino and Sergio Briguglio and M Borchardt and Emanuele Poli and Remi Dumont and Jorge Ferreira and J P Graves and Ralf Kleiber and B Rettino and Thomas Hayward-Schneider and Axel Koenies and Emmanuel Lanti and Philipp Lauber and H Leyh and Zhixin Lu and Hinrich Luetjens and Ben McMillan and Martin Campos Pinto and Baruch Rofman and Christoph Slaby and Francesco Vannini and Laurent Villard and Gregorio Vlad and Xin Wang and Fabien Widmer and Fulvio Zonca},
url = {https://iopscience.iop.org/article/10.1088/1361-6587/acce68},
year = {2023},
date = {2023-04-01},
journal = {Plasma Physics And Controlled Fusion},
volume = {65},
number = {6},
pages = {064001},
abstract = {The software stack under development within a European coordinated effort on tools for burning plasma modelling is presented. The project is organised as a Task (TSVV Task 10) under the new E-TASC initiative (Litaudon et al 2022 Plasma Phys. Control. Fusion64 034005). This is a continued effort within the EUROfusion inheriting from the earlier European coordination projects as well as research projects based at various European laboratories. The ongoing work of the TSVV Tasks is supported by the Advanced Computing Hubs. Major projects requiring the high performance computing (HPC) resources are global gyrokinetic codes and global hybrid particle-magnetohydrodynamics (MHD) codes. Also applications using the integrated modelling tools, such as the Energetic-Particle Workflow, based on the ITER Integrated Modelling & Analysis Suite (IMAS), or the code package for modelling radio-frequency heating and fast-ion generation may require intensive computation and a substantial memory footprint. The continual development of these codes both on the physics side and on the HPC side allows us to tackle frontier problems, such as the interaction of turbulence with MHD-type modes in the presence of fast particles. One of the important mandated outcomes of the E-TASC project is the IMAS-enabling of EUROfusion codes and release of the software stack to the EUROfusion community.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Andrea Zoia; Yvon Maday; Jad Dabaghi
A hybrid parareal Monte-Carlo algorithm for parabolic problems Journal Article
In: Journal Of Computational And Applied Mathematics, vol. 420, pp. 114800, 2023.
@article{zoia_1969,
title = {A hybrid parareal Monte-Carlo algorithm for parabolic problems},
author = {Andrea Zoia and Yvon Maday and Jad Dabaghi},
url = {https://www.sciencedirect.com/science/article/abs/pii/S0377042722004071},
year = {2023},
date = {2023-03-01},
journal = {Journal Of Computational And Applied Mathematics},
volume = {420},
pages = {114800},
abstract = {In this work, we propose a hybrid Monte Carlo/deterministic ??parareal-in-time'' approach devoted to accelerating Monte Carlo simulations over massively parallel computing environments for the simulation of time-dependent problems.
This parareal approach iterates on two different solvers: a low-cost ??coarse'' solver
based on a very cheap deterministic Galerkin scheme and a ??fine'' solver based on a
high-fidelity Monte Carlo resolution.
In a set of benchmark numerical experiments based on a toy model concerning
the time-dependent diffusion equation, we compare our hybrid parareal strategy with
a standard full Monte Carlo solution. In particular, we show that for a large number
of processors, our hybrid strategy significantly reduces the computational time of the
simulation while preserving its accuracy. The convergence properties of the proposed
Monte Carlo/deterministic parareal strategy are also discussed.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Martino Grasselli; Gorgia Callegaro; Alexandro Gnoatto
A fully quantization-based scheme for FBSDEs Journal Article
In: Applied Mathematics And Computation, vol. 441, pp. 127666, 2023.
@article{grasselli_2053,
title = {A fully quantization-based scheme for FBSDEs},
author = {Martino Grasselli and Gorgia Callegaro and Alexandro Gnoatto},
url = {https://www.sciencedirect.com/science/article/abs/pii/S0096300322007251},
year = {2023},
date = {2023-03-01},
journal = {Applied Mathematics And Computation},
volume = {441},
pages = {127666},
abstract = {We propose a quantization-based numerical scheme for a family of decoupled forward-backward stochastic differential equations. We simplify the scheme for the control in Pages and Sagna(2018) so that our approach is fully based on recursive marginal quantization and does not involveany Monte Carlo simulation for the computation of conditional expectations. We analyse in detail thenumerical error of our scheme and provide some examples of application to financial mathematics.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Daniel Maar; Hajer Kefi; Ekaterina Besson
Fostering positive customer attitudes and usage intentions for scheduling services via chatbots Journal Article
In: Journal Of Service Management, vol. 34, no. 2, pp. 208-230, 2023.
@article{maar_2215,
title = {Fostering positive customer attitudes and usage intentions for scheduling services via chatbots},
author = {Daniel Maar and Hajer Kefi and Ekaterina Besson},
url = {https://doi.org/10.1108/JOSM-06-2021-023},
year = {2023},
date = {2023-03-01},
journal = {Journal Of Service Management},
volume = {34},
number = {2},
pages = {208-230},
abstract = {Purpose
This article draws on a reasoned action perspective and the two fundamental dimensions (i.e. warmth and competence) of the Stereotype Content Model (SCM) to analyze customers' chatbot-related attitudes and usage intentions in service retailing. The authors investigate how chatbot, customer, and contextual characteristics, along with perceptions of chatbot warmth and competence, shape customers' chatbot-related attitudes. Furthermore, the authors analyze whether the customer generation or the service context moderates the relationship between chatbot-related attitudes and usage intentions.
Design/methodology/approach
The results are based on two studies (N = 807). Study 1 relies on a 2 (chatbot communication style: high vs low social orientation) × 2 (customer generation: generation X [GenX] vs generation Z [GenZ]) × 2 (service context: restaurant vs medical) between-subjects design. Study 2 relies on a similar number of respondents from GenX and GenZ who answered questions on scheduling a service with either the dentist or the favorite restaurant of the respondents.
Findings
GenZ shows more positive attitudes toward chatbots than GenX, due to higher perceptions of warmth and competence. While GenZ has similar attitudes toward chatbots with a communication style that is high or low in social orientation, GenX perceives chatbots with a high social orientation as warmer and has more favorable attitudes toward chatbots. Furthermore, the positive effect of chatbot-related attitudes on usage intentions is stronger for GenX than GenZ. These effects do not significantly differ between the considered contexts.
Originality/value
This research formulates future directions to stimulate debate on factors that service retailers should consider when employing chatbots.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Antoine Harfouche; Bernard Quinio; Mario Saba; Peter Saba
In: Information Systems Frontiers, vol. 25, pp. 55-70, 2023.
@article{harfouche_1996,
title = {The Recursive Theory of Knowledge Augmentation: Integrating human intuition and knowledge in Artificial Intelligence to augment organizational knowledge},
author = {Antoine Harfouche and Bernard Quinio and Mario Saba and Peter Saba},
url = {https://link.springer.com/article/10.1007/s10796-022-10352-8},
year = {2023},
date = {2023-02-01},
journal = {Information Systems Frontiers},
volume = {25},
pages = {55-70},
abstract = {Artificial intelligence (AI) has increased the ability of organizations to accumulate tacit and explicit knowledge to inform management decision-making. Despite the hype and popularity of AI, there is a noticeable scarcity of research focusing on AI's potential role in enriching and augmenting organizational knowledge. This paper develops a recursive theory of knowledge augmentation in organizations (the KAM model) based on a synthesis of extant literature and a four-year revised canonical action research project. The project aimed to design and implement a human-centric AI (called Project) to solve the lack of integration of tacit and explicit knowledge in a scientific research center (SRC). To explore the patterns of knowledge augmentation in organizations, this study extends Nonaka's SECI (socialization, externalization, combination, and internali- zation) model by incorporating the human-in-the-loop Informed Artificial Intelligence (IAI) approach. The proposed design offers the possibility to integrate experts' intuition and domain knowledge in AI in an explainable way. The findings show that organizational knowledge can be augmented through a recursive process enabled by the design and implementation of human-in-the-loop IAI. The study has important implications for research and practice.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Thomas Borsoni; Laurent Boudin; Francesco Salvarani
Compactness property of the linearized Boltzmann operator for a polyatomic gas undergoing resonant collisions Journal Article
In: Journal Of Mathematical Analysis And Applications, vol. 517, no. 1, pp. 126579, 2023.
@article{borsoni_1875,
title = {Compactness property of the linearized Boltzmann operator for a polyatomic gas undergoing resonant collisions},
author = {Thomas Borsoni and Laurent Boudin and Francesco Salvarani},
url = {https://www.sciencedirect.com/science/article/pii/S0022247X22005935?via%3Dihub},
year = {2023},
date = {2023-01-01},
journal = {Journal Of Mathematical Analysis And Applications},
volume = {517},
number = {1},
pages = {126579},
abstract = {In this paper, we investigate a compactness property of the linearized Boltzmann operator in the context of a polyatomic gas whose molecules undergo resonant collisions. The peculiar structure of resonant collision rules allows to tensorize the problem into a velocity-related one, neighbouring the monatomic case, and an internal energy-related one. Our analysis is based on a specific treatment of the internal energy contributions. We also propose a geometric variant of Grad's proof of the same compactness property in the monatomic case.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Francesco Salvarani
Kinetic models for complex systems Conference
Modelling, analysis and numerical methods of complex dynamics, Marseille, France, 2023.
@conference{salvarani_2358,
title = {Kinetic models for complex systems},
author = {Francesco Salvarani},
url = {https://conferences.cirm-math.fr/3036.html},
year = {2023},
date = {2023-06-01},
booktitle = {Modelling, analysis and numerical methods of complex dynamics},
address = {Marseille, France},
keywords = {},
pubstate = {published},
tppubtype = {conference}
}
Francesco Salvarani
On the homogenization of the linear Boltzmann equation Conference
Seminario EDP, Universidad Autónoma de Madrid, Spain, 2023.
@conference{salvarani_2287,
title = {On the homogenization of the linear Boltzmann equation},
author = {Francesco Salvarani},
url = {https://sites.google.com/view/seminarioedpsuam-icmat/home},
year = {2023},
date = {2023-05-01},
booktitle = {Seminario EDP},
address = {Universidad Autónoma de Madrid, Spain},
keywords = {},
pubstate = {published},
tppubtype = {conference}
}
Pierre Lefebvre; Ahmed Azough; Nicolas Travers; Driss Yakoubi
GdR Madics, Troyes, 2023.
@conference{lefebvre_2306,
title = {Vid2Graph : un framework pour l'extraction de connaissances et l'analyse sémantique des flux de vidéosurveillance de systèmes distribués},
author = {Pierre Lefebvre and Ahmed Azough and Nicolas Travers and Driss Yakoubi},
url = {https://www.dataia.eu/evenements/5eme-symposium-gdr-madics},
year = {2023},
date = {2023-05-01},
booktitle = {GdR Madics},
address = {Troyes},
abstract = {La vidéosurveillance s'est considérablement développée ces dernières années. Les sources sont de plus en plus nombreuses, en mouvement ou avec des qualités variables : on parle de système distribué. L'analyse des données produites par de tels systèmes est devenue un enjeu majeur. En effet, si la détection des objets et des actions capturés par une caméra individuelle est aujourd'hui accessible à travers les modèles d'apprentissage automatique ou de reconnaissance de forme, la modélisation et la détection automatique d'évènements longue durée et faisant intervenir un réseau de caméras de surveillance restent un défi.
Ainsi, comment permettre la détection d'évènements complexes dans un réseau de caméras de surveillance hétérogènes et distribuées ?
Afin de répondre à cette problématique, nous proposons un framework pour l'extraction et l'enrichissement de caractéristiques à partir de caméras de vidéosurveillance. Il repose sur 1) un pipeline de modèles de Deep Learning pour l'extraction de caractéristiques de vidéos (extraction d'images-clés, détections d'objets / segmentation d'instances, extraction d'attributs, détection de relations spatiales, réidentification), 2) un module de génération d'un graphe de connaissances, 3) un module d'enrichissement du graphe pour améliorer la qualité des détections, et 4) un module d'analyse pour la détection d'événements complexes sur le graph. Son architecture modulaire permet d'interchanger les étapes d'extraction de caractéristiques provenant des vidéos. Le poster détaillera le framework proposé et illustrera le processus de création du graphe à partir de vidéos provenant du benchmark Smart-City CCTV Violence Detection Dataset (SCVD).
L'intérêt de l'approche est de pouvoir, à terme, se focaliser sur la sémantique des vidéos comme l'isolation de segments vidéo ou d'actions (filtres/projections sur le graph), la détection d'événements ou activités au moyen d'algorithmes de Graph Mining / GNN.},
keywords = {},
pubstate = {published},
tppubtype = {conference}
}
Wissal Benjira; Faten Atigui; Malika Grim-Yefsah; Benedicte Bucher; Nicolas Travers
GdR Madics, Troyes, 2023.
@conference{benjira_2308,
title = {Data lake and metadata repositories to develop city sustainability indicators using open Big Data. Applied to sports practices},
author = {Wissal Benjira and Faten Atigui and Malika Grim-Yefsah and Benedicte Bucher and Nicolas Travers},
url = {https://www.madics.fr/event/symposium-madics-5/},
year = {2023},
date = {2023-05-01},
booktitle = {GdR Madics},
address = {Troyes},
abstract = {La disponibilité croissante des données est une opportunité pour mieux observer et comprendre le monde réel. Produire des indicateurs mesurant les Objectifs de Developpement Durable (ODD) est un enjeux sociétal majeur, nécessitant des sources hétérogènes, pour comparer des situations dans l'espace et dans le temps. Par exemple, l'ODD11.7 s'intéresse à l'accès pour tous aux espaces publics sûrs, tels que les espaces verts, les espaces pour les pratiques sportives. Notre travail se focalise particulièrement sur l'étude de l'impact des méga-événements sportifs (ex. JO2024) sur la pratique sportive dans la ville durable et l'impact de l'organisation de méga-événements sur ces villes. L'organisation de ces événements sportifs revêt donc de multiples enjeux managériaux pour les territoires d'accueil. Selon Chappelet, les méga-événements ont le pouvoir [...] d'impacter suffisamment le territoire pour que ce dernier puisse en bénéficier durablement. Ils laissent un "héritage" sur leur passage que Preuss définit comme étant « tous les résultats qui affectent les personnes et/ou l'espace » sur la durée.
L'étude de l'impact des évènements sportifs nécessite l'exploitation de données massives connues par leur volume, variété et vélocité. Il est également indispensable de pouvoir les croiser. Seulement, il apparaît que le potentiel de ces données n'est pas entièrement exploité dû à l'absence de cadre unificateur. De ce fait, notre sujet a pour objectif de comprendre comment les données peuvent servir à mesurer l'héritage d'un méga-événement. Pour obtenir une évaluation de cet héritage, nous proposons une approche reposant sur un Framework simplifié qui facilite l'identification, le traitement ainsi que l'interprétation du croisement des données. Le lac sémantique obtenu est représenté et structuré sous forme de base de données graph facilitant le rapprochement des données avec 1) un schéma de graph de données unifié, 2) des règles d'enrichissement du graph, 3) des opérations sur le graph pour produire des mesures et leur composition pour définir les indicateurs.
Nous présenterons notre approche en nous reposant sur deux cas d'étude plus précis :
- La comparaison des parcours sportifs en ville, à vélo ou à pied, avant et après un mégaévènement à l'aide d'open data
- La comparaison des parcours sportifs en ville, à vélo ou à pied, entre deux villes en se fondant sur des données produites par différentes administrations et participants et pourvues de biais différents.},
keywords = {},
pubstate = {published},
tppubtype = {conference}
}
Nicolas Travers; Victor David; Raphaël Fournier-S'niehotta
Where is the Truth? From Factoids to Maximum A-Posteriori Inference on Knowledge Graphs Conference
eHealth & ethics, Pôle Léonard de Vinci Paris La Défense, 2023.
@conference{travers_2309,
title = {Where is the Truth? From Factoids to Maximum A-Posteriori Inference on Knowledge Graphs},
author = {Nicolas Travers and Victor David and Raphaël Fournier-S'niehotta},
url = {https://conferences.dvrc.fr/eHealth-ethics23/schedule.php},
year = {2023},
date = {2023-04-01},
booktitle = {eHealth & ethics},
address = {Paris La Défense},
organization = {Pôle Léonard de Vinci},
abstract = {Reasoning on uncertain and complex data to infer the most probable outcome is a crucial task in finding the
truth in complex sets of contradictory factoids (potential facts), such as confronting a hypothesis of disease
over a set of symptoms for a population. Excelling at this task involves examining logical links between
factoids, surfacing the conflicts among facts, and filtering them out to reach a consistent state called goal
recognition.
Knowledge graphs (KGs) are a key tool for modelling actions, represented as facts with a (subject,
predicate, object) triplet. Several approaches have been developed to reason on KGs, and one of them,
Markov Logic Networks [Chekol et al., 2016, Rinc ?e et al., 2018], propose probabilistic reasoning in a unified
formalism supporting uncertainty, which is key for goal recognition. However, only few MLN-based KG
reasoning frameworks handle both uncertainty and temporal data [Chekol et al., 2017], and none can handle
a fully uncertain universe where any fact or rule may be uncertain.
For goal recognition, reasoning under uncertainty and inconsistency is at the basis of methodology: the
validity of the knowledge of any hypothesis remains questionable. Temporal information is also crucial:
outside of a temporal interval, a fact becomes false. By using time intervals in knowledge, it is possible
to refine the reasoning on medical hypothesis during a sequence of events. Once all hypotheses has been
modelled, the goal recognition is to predict the most likely consistent hypothesis among all factoids/symptoms
from a population. In [Ha et al., 2011, Lester et al., 2013, Baikadi et al., 2014, Ha et al., 2014] the authors
propose MLN-based learning approaches and in [Min et al., 2014, Min et al., 2016] deep Learning approaches
to enhance goal recognition. However, those representations hardly handle a fully uncertain universe (facts
and rules). Moreover, they are not explainable, one cannot trace back the facts that leads to a given
conclusion (goal).},
keywords = {},
pubstate = {published},
tppubtype = {conference}
}
Julie Escurignan
Médiévalismes en Séries, Paris, France, 2023.
@conference{escurignan_2178,
title = {Fans de séries médiévalistes ou fans du Moyen Age ? La réception médiatique des séries médiévalistes contemporaines},
author = {Julie Escurignan},
url = {https://modmed.hypotheses.org/tag/series-televisees},
year = {2023},
date = {2023-03-01},
booktitle = {Médiévalismes en Séries},
address = {Paris, France},
keywords = {},
pubstate = {published},
tppubtype = {conference}
}
Julie Escurignan
Médiévalismes en Séries, Online, 2023.
@conference{escurignan_2428,
title = {Fans de séries médiévalistes ou fans du Moyen Age ? La réception médiatique des séries médiévalistes contemporaines},
author = {Julie Escurignan},
url = {https://modmed.hypotheses.org/2532},
year = {2023},
date = {2023-03-01},
booktitle = {Médiévalismes en Séries},
address = {Online},
keywords = {},
pubstate = {online},
tppubtype = {conference}
}
Guillaume Guérard; Sofiane Ben Amor; Maxence Choufa; Sonia Djebali; Clement Cornet; Loup-Noé Levy; Hai Tran
Pretopology-based Clustering for Mixed Data Conference
ROADEF 2023, Rennes , France, 2023.
@conference{guerard_2244,
title = {Pretopology-based Clustering for Mixed Data},
author = {Guillaume Guérard and Sofiane Ben Amor and Maxence Choufa and Sonia Djebali and Clement Cornet and Loup-Noé Levy and Hai Tran},
url = {https://roadef2023.sciencesconf.org/436878/document},
year = {2023},
date = {2023-02-01},
booktitle = {ROADEF 2023},
address = {Rennes , France},
abstract = {The energy performance of buildings represents a major issue of the 21st century. Many
solutions have been discussed to improve buildings' energy performance [1, 4], but the actions
to take differ from one building to another. In other words, current solutions are built on
a case-by-case basis and cannot be extrapolated easily. Indeed, it is difficult to find generic
solutions due to their complexity and heterogeneity.
By placing buildings in groups and subgroups, one can define relevant energy optimization
recommendations without auditing each building individually. Because initial labels are not
always defined, clustering is relevant in our case. Since we seek for intrinsic similarities between
groups and subgroups, hierarchical clustering is needed. Buildings are described with mixed
data. They include numerical data such as surface or number of floors, and categorical data like
types of heating or insulation materials. Few clustering algorithms exist for mixed data, and
even fewer are hierarchical. In this article, we present a method for the hierarchical clustering
of mixed data based on pretopology.},
keywords = {},
pubstate = {published},
tppubtype = {conference}
}
Fawaz Baddar Al Hussan; Faten Baddar Alhusan; Shameek Sinha; Ismail Golgeci
How come you cannot identify your Key-Customers: Evidence from Jordan Conference
AMA Global Marketing Sig, Chile, Santiago, 2023.
@conference{baddar_al_hussan_2449,
title = {How come you cannot identify your Key-Customers: Evidence from Jordan},
author = {Fawaz Baddar Al Hussan and Faten Baddar Alhusan and Shameek Sinha and Ismail Golgeci},
year = {2023},
date = {2023-02-01},
booktitle = {AMA Global Marketing Sig},
address = {Chile, Santiago},
abstract = {The company's customers are important for its existence and development in many ways. Large customers were and still are treated differently from smaller customers. The large customers given key account status create specific opportunities and risks for any firm. They create opportunities for the company by making it stronger in the market, increasing its profitability and guaranteeing output. Risks wise, the loss of even one of these ?key' accounts can threaten the existence of the seller company. For all these reasons, identifying and managing these customers is necessary for surviving the highly competitive markets. This challenge increases when a multinational firm operates in a host country and subsequently invests in that foreign environment. This research aims to provide a detailed understanding of the nature of key account (KA) identification, selection and strategy implementation in the Arab context, which provides a unique business environment. Our qualitative study suggests that KA identification and selection does not depend solely on quantitative criteria but also on qualitative criteria that are influenced by the cultural, religious and institutional environment of the host country. Drawing on customer portfolio management approach in B2B contexts and Shapiro & Bonomo's market segmentation framework, we identify the relevant criteria in identifying and selecting KAs, and how it differs from the extant literature. We close with a discussion and implications for foreign firms in their strategy implementation and avenues for future research.},
keywords = {},
pubstate = {accepted},
tppubtype = {conference}
}
Oussama Ayoub; Ludovic Li; Christophe Rodrigues; Nicolas Travers
LoGE: Expansion Locale-Globale de document non supervise avec un moteur de recherche Extensible Conference
TextMine - Groupe de travail sur la fouille de textes @ confrence EGC, Lyon, 2023.
@conference{ayoub_2078,
title = {LoGE: Expansion Locale-Globale de document non supervise avec un moteur de recherche Extensible},
author = {Oussama Ayoub and Ludovic Li and Christophe Rodrigues and Nicolas Travers},
url = {https://textmine.sciencesconf.org/resource/page/id/4},
year = {2023},
date = {2023-01-01},
booktitle = {TextMine - Groupe de travail sur la fouille de textes @ confrence EGC},
address = {Lyon},
abstract = {Avec la croissance continue des donnes textuelles que les systmes d'information modernes doivent grer, des solutions de recherche d'information sont ncessaires pour trouver efficacement le meilleur ensemble de documents pour une demande donne.Pour rsoudre ce problme, nous proposons un moteur de recherche extensible qui vise gnrer une expansion des documents en s'appuyant sur des mthodes rcentes d'apprentissage profond et mis en uvre sur Elasticsearch. Pour gnrer de nouveaux mots pour un document, un modle de langage masqu d'apprentissage profond est utilis pour infrer des mots apparents.La dmonstration montrera la fois l'extensibilit de notre cadre de gnration d'expansions, l'efficacit de l'valuation et l'impact de diverses expansions sur la correspondance des requtes.},
keywords = {},
pubstate = {published},
tppubtype = {conference}
}
Hamidreza Vanaei; Sofiane Khelladi; Abbas Tcharkhtchi
Nanotechnology for Pain-Free Dentistry Book Section
In: Sabu Thomas, R. M. Baiju (Ed.): Nanomaterials in Dental Medicine, vol. 1, pp. 111-120, Springer, https://link.springer.com/chapter/10.1007/978-981-19-8718-2_6, 2023, ISBN: 978-981-19-8718-2.
@incollection{vanaei_2293,
title = {Nanotechnology for Pain-Free Dentistry},
author = {Hamidreza Vanaei and Sofiane Khelladi and Abbas Tcharkhtchi},
editor = {Sabu Thomas, R. M. Baiju},
url = {https://doi.org/10.1007/978-981-19-8718-2_6},
issn = {978-981-19-8718-2},
year = {2023},
date = {2023-04-01},
booktitle = {Nanomaterials in Dental Medicine},
volume = {1},
pages = {111-120},
publisher = {Springer},
address = {https://link.springer.com/chapter/10.1007/978-981-19-8718-2_6},
edition = {1},
abstract = {Nanotechnology is progressively changing the human life and health care in recent years. This technology has the capacity of changing the entire healthcare techniques by proposing novel disease prevention techniques and inventing nanorobots. One of the most important applications of nanotechnology is in the dental medicine that is capable of covering operations free of pain. As pain management is one of the most challenging features in this field of study, incorporation of nanotechnology and pain-free dentistry is of the most concern in both academy and industry. In this chapter, efforts have been taken into account to review various nanotechnologies engaged in dentistry as well as their impact on the pain-free dentistry.},
keywords = {},
pubstate = {published},
tppubtype = {incollection}
}
Victor David; Raphaël Fournier-S'niehotta; Nicolas Travers
NeoMaPy: a Framework for Computing MAP inference on Temporal Knowledge Graphs Proceedings Article
In: International Joint Conference on Artificial Intelligence, pp. 7123-7126, Macao, China, 2023.
@inproceedings{david_2307,
title = {NeoMaPy: a Framework for Computing MAP inference on Temporal Knowledge Graphs},
author = {Victor David and Raphaël Fournier-S'niehotta and Nicolas Travers},
url = {https://www.ijcai.org/proceedings/2023/831},
year = {2023},
date = {2023-08-01},
booktitle = {International Joint Conference on Artificial Intelligence},
pages = {7123-7126},
address = {Macao, China},
abstract = {Markov Logic Networks (MLN) are used for rea- soning on uncertain and inconsistent temporal data. We proposed the TMLN (Temporal Markov Logic Network) which extends them with sorts/types, weights on rules and facts, and various temporal consistencies. The NeoMaPy framework integrates it in a knowledge graph based on conflict graphs, which offers flexibility for reasoning with parame- tric Maximum A Posteriori (MAP) inferences, effi- ciency thanks to an optimistic heuristic and interac- tive graph visualization for results explanation.},
keywords = {},
pubstate = {published},
tppubtype = {inproceedings}
}
Amrid Mammeri; Messipssa Aoudjit; Issiaka Traore; Ivan Dobrev; Hamidreza Vanaei; Sofiane Khelladi; Kamel Azzouz
Aerodynamic and Aeroacoustic Performance of Cross-Flow Fan: A Comparison through Additive Manufacturing and Conventional Methods Proceedings Article
In: 2023 3rd International Conference on Electrical, Computer, Communications and Mechatronics Engineering (ICECCME), IEEE, Tenerife, Canary Islands, Spain, 2023, ISBN: 979-8-3503-2297-2.
@inproceedings{mammeri_2467,
title = {Aerodynamic and Aeroacoustic Performance of Cross-Flow Fan: A Comparison through Additive Manufacturing and Conventional Methods},
author = {Amrid Mammeri and Messipssa Aoudjit and Issiaka Traore and Ivan Dobrev and Hamidreza Vanaei and Sofiane Khelladi and Kamel Azzouz},
url = {https://doi.org/10.1109/ICECCME57830.2023.10253175},
issn = {979-8-3503-2297-2},
year = {2023},
date = {2023-07-01},
booktitle = {2023 3rd International Conference on Electrical, Computer, Communications and Mechatronics Engineering (ICECCME)},
publisher = {IEEE},
address = {Tenerife, Canary Islands, Spain},
abstract = {Cross-Flow Fans (CFFs), also known as Tangential fan, are widely used in various industries, particularly in automotive or domestic air conditioning, and have recently attained much attention. Alongside the significant research works, traditional techniques and additive manufacturing techniques have exclusively revealed stimulating results in turbomachinery. Despite various works either in academic sectors or industry, and to meet the requirement of performing research works, CFFs have been manufactured using different types of 3D-printer: i) rotor using stereolithography (SLA), ii) plastic rotor using selective laser sintering (SLS-plastic), iii) aluminum rotor using selective laser sintering (SLS-aluminum), further with iv) machined rotor using CNC process. The objective is to compare their aerodynamics and aeroacoustics performances for facilitating the production of these fans. It has been found that the CNC rotor is different in terms of aeroacoustic behavior due to its difference internal diameter edge profile and shape. SLS rotors expressed a higher roughness compared to SLA rotor. Considering aeroacoustic behavior, building process, complexity, balancing, time and cost, SLA process found to be more applicable for the development of a cross flow fan.},
keywords = {},
pubstate = {published},
tppubtype = {inproceedings}
}
Julie Escurignan
Réattirer les fans post-Covid : tourisme de fans, identités régionales et dispositifs socio-numériques Proceedings Article
In: Congrès de la SFSIC, Université Bordeaux Montaigne, Bordeaux, France, 2023.
@inproceedings{escurignan_2183,
title = {Réattirer les fans post-Covid : tourisme de fans, identités régionales et dispositifs socio-numériques},
author = {Julie Escurignan},
url = {https://www.sfsic.org/evenements-sfsic/congres-sfsic/congres-sfsic-bordeaux-2023/},
year = {2023},
date = {2023-06-01},
booktitle = {Congrès de la SFSIC},
address = {Université Bordeaux Montaigne, Bordeaux, France},
keywords = {},
pubstate = {published},
tppubtype = {inproceedings}
}
Julie Escurignan
Développement durable et responsabilité sociale dans la stratégie de marque des musées : L'étude de cas du Palais de Tokyo Proceedings Article
In: ACFAS, 425, rue De La Gauchetière Est Montréal (Québec), 2023.
@inproceedings{escurignan_2429,
title = {Développement durable et responsabilité sociale dans la stratégie de marque des musées : L'étude de cas du Palais de Tokyo},
author = {Julie Escurignan},
url = {https://www.acfas.ca/evenements/congres},
year = {2023},
date = {2023-05-01},
booktitle = {ACFAS},
address = {425, rue De La Gauchetière Est Montréal (Québec)},
keywords = {},
pubstate = {published},
tppubtype = {inproceedings}
}
Basma Jaffal-Moutarda; Driss Yakoubi
A splitting method for a stationary second grade fluid model Proceedings Article
In: The 9th International Conference on Modeling, Simulation and Applied Optimization, Marrakech. Morroco, 2023.
@inproceedings{jaffal-moutarda_2368,
title = {A splitting method for a stationary second grade fluid model},
author = {Basma Jaffal-Moutarda and Driss Yakoubi},
url = {http://2021.icmsao.org/program/},
year = {2023},
date = {2023-04-01},
booktitle = {The 9th International Conference on Modeling, Simulation and Applied Optimization},
address = {Marrakech. Morroco},
keywords = {},
pubstate = {published},
tppubtype = {inproceedings}
}
Julie Escurignan; Pascal Brassier
Séries télévisées et réception critique des pratiques managériales : le cas de The Dropout, fiction du scandale Theranos Proceedings Article
In: Management en Séries, Université Gustave Eiffel, Champs-sur-Marne, France, 2023.
@inproceedings{escurignan_2182,
title = {Séries télévisées et réception critique des pratiques managériales : le cas de The Dropout, fiction du scandale Theranos},
author = {Julie Escurignan and Pascal Brassier},
url = {https://managementserie.sciencesconf.org/data/pages/programme_colloque_mgt_Series_saison1_03_02_2023.pdf},
year = {2023},
date = {2023-03-01},
booktitle = {Management en Séries},
address = {Université Gustave Eiffel, Champs-sur-Marne, France},
keywords = {},
pubstate = {published},
tppubtype = {inproceedings}
}
Sonia Djebali; Quentin Gabot; Guillaume Guérard
Hierarchical Clustering and Measure for Tourism Profiling Proceedings Article
In: 6th APWeb-WAIM International Joint Conference on Web and Big Data, pp. 158-165, Nanjing, China, 2023.
@inproceedings{djebali_1936,
title = {Hierarchical Clustering and Measure for Tourism Profiling},
author = {Sonia Djebali and Quentin Gabot and Guillaume Guérard},
url = {https://link.springer.com/chapter/10.1007/978-3-031-25198-6_12},
year = {2023},
date = {2023-02-01},
booktitle = {6th APWeb-WAIM International Joint Conference on Web and Big Data},
volume = {13422},
pages = {158-165},
address = {Nanjing, China},
keywords = {},
pubstate = {published},
tppubtype = {inproceedings}
}