Search results for " Models"
showing 10 items of 4240 documents
Particle Group Metropolis Methods for Tracking the Leaf Area Index
2020
Monte Carlo (MC) algorithms are widely used for Bayesian inference in statistics, signal processing, and machine learning. In this work, we introduce an Markov Chain Monte Carlo (MCMC) technique driven by a particle filter. The resulting scheme is a generalization of the so-called Particle Metropolis-Hastings (PMH) method, where a suitable Markov chain of sets of weighted samples is generated. We also introduce a marginal version for the goal of jointly inferring dynamic and static variables. The proposed algorithms outperform the corresponding standard PMH schemes, as shown by numerical experiments.
Biological Nutrient Removal Model No. 2 (BNRM2): a general model for wastewater treatment plants
2013
This paper presents the plant-wide model Biological Nutrient Removal Model No. 2 (BNRM2). Since nitrite was not considered in the BNRM1, and this previous model also failed to accurately simulate the anaerobic digestion because precipitation processes were not considered, an extension of BNRM1 has been developed. This extension comprises all the components and processes required to simulate nitrogen removal via nitrite and the formation of the solids most likely to precipitate in anaerobic digesters. The solids considered in BNRM2 are: struvite, amorphous calcium phosphate, hidroxyapatite, newberite, vivianite, strengite, variscite, and calcium carbonate. With regard to nitrogen removal via…
Computing the Arrangement of Circles on a Sphere, with Applications in Structural Biology
2009
International audience; Balls and spheres are the simplest modeling primitives after affine ones, which accounts for their ubiquitousness in Computer Science and Applied Mathematics. Amongst the many applications, we may cite their prevalence when it comes to modeling our ambient 3D space, or to handle molecular shapes using Van der Waals models. If most of the applications developed so far are based upon simple geometric tests between balls, in particular the intersection test, a number of applications would obviously benefit from finer pieces of information. Consider a sphere $S_0$ and a list of circles on it, each such circle stemming from the intersection between $S_0$ and another spher…
Dacarbazine-mediated upregulation of NKG2D ligands on tumor cells activates NK and CD8 T cells and restrains melanoma growth.
2013
International audience; Dacarbazine (DTIC) is a cytotoxic drug widely used for melanoma treatment. However, the putative contribution of anticancer immune responses in the efficacy of DTIC has not been evaluated. By testing how DTIC affects host immune responses to cancer in a mouse model of melanoma, we unexpectedly found that both natural killer (NK) and CD8(+) T cells were indispensable for DTIC therapeutic effect. Although DTIC did not directly affect immune cells, it triggered the upregulation of NKG2D ligands on tumor cells, leading to NK cell activation and IFNγ secretion in mice and humans. NK cell-derived IFNγ subsequently favored upregulation of major histocompatibility complex cl…
Social cognition theories and behavior change in COVID-19: A conceptual review.
2022
The COVID-19 pandemic has had unprecedented health, economic, and social consequences worldwide. Although contact reductions and wearing face coverings have reduced infection rates, and vaccines have reduced illness severity, emergence of new variants of the coronavirus that causes COVID-19, and the shift from pandemic to endemic patterns of infection, highlights the importance of ongoing preventive behavior adherence to manage future outbreaks. Research applying social cognition theories may assist in explaining variance in these behaviors and inform the development of efficacious behavior change interventions to promote adherence. In the present article, we summarize research applying the…
Sex-role orientation and memory for gender-related terms: Another uncertain link
1989
Two studies are reported which investigate the relationship between sex-role orientation and memory for gender-related terms. Based on the concept of ‘cognitive schema’, theoretical models have recently been advanced suggesting that the schematic cognitive representation of gender facilitates the recall of words pertinent to gender. One of these models, Markus' self-schema theory, proposes that masculine and feminine sex-typed individuals have a better memory for terms that correspond to their respective self-schemata. In contrast, Bem's gender schema theory implies that sex-typed individuals have a better memory for the category of gender as a whole, i.e. for both masculine and feminine te…
Les élèves en accompagnement scolaire : adéquation entre public visé et public accueilli
2002
This article examines the adjustment between pupils targeted to study in after school programs and pupils who are already in attendance. Several analyses have been drawn up on a large cross-section of seven and ten year-old pupils and have shown that most of them have social problems and/or are under-achieving. However, a third of the cross-section are not experiencing difficulties and therefore should not have been enrolled. Regarding the selection process of the after school programs, the analysis also shows that weak and foreign pupils more frequently seek school support after the normal school day.
Testing a model for the monitoring of worked-out algebra-problem examples: from behaviours to outcomes on a math task
2021
This study aimed at testing an extension of a theoretical model for the metacognitive monitoring mechanism implied in the detection of inconsistencies when the information provided includes abstract symbols in addition to plain text. Ninety-four postgraduates of STEM specialities were asked to read a worked-out algebra-problem example and to report any incoherence, inconsistency, or error detected in the statement or in the solving procedure. A set of model inspired indexes was defined to describe participants¿ behaviour along the task. The Read & Answer software was used to record online individual processing data and participants¿ reports. Results supported model predictions. Indexes corr…
Utilisation du numérique par les enseignants à l’université : description et analyse des facteurs explicatifs
2019
Dans cet article, nous nous intéressons à la nature des technologies de l’information et de la communication (TIC) mobilisées par les enseignants universitaires pour enseigner et aux facteurs explicatifs de cette utilisation. Nous procédons d’abord à un éclairage théorique notamment concernant les concepts de « TIC » et d’« utilisation ». Puis, à l’appui des données recueillies en mai 2016 auprès de 248 enseignants d’une université française, nous montrons que les TIC mobilisées par les enseignants à l’intérieur, mais aussi en dehors des heures de cours, sont plutôt d’ordre générique en opposition aux technologies plus sophistiquées. Les enseignants utilisent par ailleurs davantage les TIC …
L’historien et ses modèles
2010
Parler des modèles en histoire est une affaire délicate, car le mot recouvre des pratiques historiennes différentes depuis son apparition dans la discipline, après la dernière guerre mondiale. Pour une minorité d’historiens surtout spécialisés en histoire économique, il correspond à une vision nouvelle de la discipline qui tenterait d’intégrer certaines démarches mathématiques, en particulier aujourd’hui la théorie des jeux. Pour d’autres, en revanche, parler de modèles relèverait surtout d’une évolution du vocabulaire, sans impliquer de véritable mutation disciplinaire. Les historiens construisent et utilisent surtout des modèles explicatifs, voire palliatifs quand ils ont de trop grandes …