51 research outputs found
Analyzing the determinant characteristics for a good performance at enade brazilian exam stratified by teaching modality: face-to-face versus online
The National Student Performance Exam (ENADE) annually evaluates different Brazilian higher education courses. This exam considers both face-to-face and distance learning courses. Distance learning is growing increasingly, especially during the coronavirus (COVID-19) pandemic. This study applies different techniques for selecting ENADE 2018 database characteristics, like information gain, gain rate, symmetric uncertainty, Pearson correlation, and relief F. The objective of the work is to discover which personal and socioeconomic characteristics are decisive for the student's performance at ENADE, whether the student is in the context of Distance Education or face-to-face. It can be concluded, among other results, that: the father's level of education directly influences performance; the higher the income, the better the performance; and white students have better performance than black and brown-skinned ones. Thus, the results obtained in this study may initiate analyzes of public policies towards improving performance at ENADE.This study was supported by CNPq (305805/2021-5) and PNPD/CAPES (464880/2019-00)
Large Scale Cross-Correlations in Internet Traffic
The Internet is a complex network of interconnected routers and the existence
of collective behavior such as congestion suggests that the correlations
between different connections play a crucial role. It is thus critical to
measure and quantify these correlations. We use methods of random matrix theory
(RMT) to analyze the cross-correlation matrix C of information flow changes of
650 connections between 26 routers of the French scientific network `Renater'.
We find that C has the universal properties of the Gaussian orthogonal ensemble
of random matrices: The distribution of eigenvalues--up to a rescaling which
exhibits a typical correlation time of the order 10 minutes--and the spacing
distribution follow the predictions of RMT. There are some deviations for large
eigenvalues which contain network-specific information and which identify
genuine correlations between connections. The study of the most correlated
connections reveals the existence of `active centers' which are exchanging
information with a large number of routers thereby inducing correlations
between the corresponding connections. These strong correlations could be a
reason for the observed self-similarity in the WWW traffic.Comment: 7 pages, 6 figures, final versio
A local search for the Job-shop Scheduling Problem with Constraint Programming
International audienc
Planetary boundaries, territorial planning tools and resilience : Case study on South-Loireâs territorial planning scheme (France)
International audiencePlanetary boundaries (PB) provides a good framework for understanding and awareness-raising of ecological issues on a global scale. Taking note that local decisions generate the environmental impacts and pressures that contribute to crossing PBs, there are some research and operational issues in downscaling the « PB thinking » to local decision-making levels. What approach could be used to assess the âresilienceâ to which territorial planning scheme (TPS) contribute in front of exceeding PBs? A case study on a South-Loire (France)âs TPS is presented. A qualitative analysis of the mechanisms and interactions was carried out from two perspectives: (1) the PBsâ threshold crossing effects on the South-Loire territory (risks), and (2) the projected effects of the TPS on the PBs (impacts and pressures). The action plans were qualitatively assessed in terms of their (direct or indirect) influence on the PBs with a DPSIR-type method. In parallel, the action plans are assigned to different resilience criteria. Around 42% of the action intentions do not explicitly address the PBs. Almost 30% directly target Climate change and 15% the Land use change PB. Beyond this explicit reading, the description of the implicit effects allows us to reveal causal links (positive or negative) to other PBs. We then show how action plans aimed at either absorptive resilience, adaptive resilience or, more rarely, transformative resilience. A new systemic cross-reading grid and a qualitative diagnosis are thus proposed to assess territorial planning tools in the light of planetary boundaries and different kinds of âresilienceâ
Planetary boundaries, territorial planning tools and resilience : Case study on South-Loireâs territorial planning scheme (France)
International audiencePlanetary boundaries (PB) provides a good framework for understanding and awareness-raising of ecological issues on a global scale. Taking note that local decisions generate the environmental impacts and pressures that contribute to crossing PBs, there are some research and operational issues in downscaling the « PB thinking » to local decision-making levels. What approach could be used to assess the âresilienceâ to which territorial planning scheme (TPS) contribute in front of exceeding PBs? A case study on a South-Loire (France)âs TPS is presented. A qualitative analysis of the mechanisms and interactions was carried out from two perspectives: (1) the PBsâ threshold crossing effects on the South-Loire territory (risks), and (2) the projected effects of the TPS on the PBs (impacts and pressures). The action plans were qualitatively assessed in terms of their (direct or indirect) influence on the PBs with a DPSIR-type method. In parallel, the action plans are assigned to different resilience criteria. Around 42% of the action intentions do not explicitly address the PBs. Almost 30% directly target Climate change and 15% the Land use change PB. Beyond this explicit reading, the description of the implicit effects allows us to reveal causal links (positive or negative) to other PBs. We then show how action plans aimed at either absorptive resilience, adaptive resilience or, more rarely, transformative resilience. A new systemic cross-reading grid and a qualitative diagnosis are thus proposed to assess territorial planning tools in the light of planetary boundaries and different kinds of âresilienceâ
Planetary boundaries, territorial planning tools and resilience : Case study on South-Loireâs territorial planning scheme (France)
International audiencePlanetary boundaries (PB) provides a good framework for understanding and awareness-raising of ecological issues on a global scale. Taking note that local decisions generate the environmental impacts and pressures that contribute to crossing PBs, there are some research and operational issues in downscaling the « PB thinking » to local decision-making levels. What approach could be used to assess the âresilienceâ to which territorial planning scheme (TPS) contribute in front of exceeding PBs? A case study on a South-Loire (France)âs TPS is presented. A qualitative analysis of the mechanisms and interactions was carried out from two perspectives: (1) the PBsâ threshold crossing effects on the South-Loire territory (risks), and (2) the projected effects of the TPS on the PBs (impacts and pressures). The action plans were qualitatively assessed in terms of their (direct or indirect) influence on the PBs with a DPSIR-type method. In parallel, the action plans are assigned to different resilience criteria. Around 42% of the action intentions do not explicitly address the PBs. Almost 30% directly target Climate change and 15% the Land use change PB. Beyond this explicit reading, the description of the implicit effects allows us to reveal causal links (positive or negative) to other PBs. We then show how action plans aimed at either absorptive resilience, adaptive resilience or, more rarely, transformative resilience. A new systemic cross-reading grid and a qualitative diagnosis are thus proposed to assess territorial planning tools in the light of planetary boundaries and different kinds of âresilienceâ
Efficient Constraint Programming Approaches for routing problem: a case study for the VRP
International audienceNumerous routing or scheduling problems encompass a lot of constraints including due date, time windows, precedence constraints or disjunctive constraints. Exact resolution based on linear formulation or heuristic based approaches should expect diïŹculties in ïŹnding a simple feasible solution. Strongly constraints optimization problems To face this challenge, some approaches based on constraint programming are of great interest taking advantages of the great number of constraints to satisfy and providing one solution in short computation ïŹrst and capable of investagating new best solution in the neighborhood of one initial solution. In numerous problems conversions of well-know mixed integer programming (MILP) formulation to CP, lead to poor CP performances. Well-known custom-made CP formulation are required to obtain CP formulation of interest. The generality of the CP approach and its eïŹciency is demonstrated to a VRP where the MILP formulation conversion lead to a 150s resolution time and the well-known custom-made CP formulation provide a resolution in 0.8s. The generic appaoch for solving combinatorial otpimization problem with a CP paradigm is based on global constraints, enumeration technics, propagating technics ... to facilitate strong reduction of domain and a proper exploration of the search tree
Planetary boundaries, territorial planning tools and resilience : Case study on South-Loireâs territorial planning scheme (France)
International audiencePlanetary boundaries (PB) provides a good framework for understanding and awareness-raising of ecological issues on a global scale. Taking note that local decisions generate the environmental impacts and pressures that contribute to crossing PBs, there are some research and operational issues in downscaling the « PB thinking » to local decision-making levels. What approach could be used to assess the âresilienceâ to which territorial planning scheme (TPS) contribute in front of exceeding PBs? A case study on a South-Loire (France)âs TPS is presented. A qualitative analysis of the mechanisms and interactions was carried out from two perspectives: (1) the PBsâ threshold crossing effects on the South-Loire territory (risks), and (2) the projected effects of the TPS on the PBs (impacts and pressures). The action plans were qualitatively assessed in terms of their (direct or indirect) influence on the PBs with a DPSIR-type method. In parallel, the action plans are assigned to different resilience criteria. Around 42% of the action intentions do not explicitly address the PBs. Almost 30% directly target Climate change and 15% the Land use change PB. Beyond this explicit reading, the description of the implicit effects allows us to reveal causal links (positive or negative) to other PBs. We then show how action plans aimed at either absorptive resilience, adaptive resilience or, more rarely, transformative resilience. A new systemic cross-reading grid and a qualitative diagnosis are thus proposed to assess territorial planning tools in the light of planetary boundaries and different kinds of âresilienceâ
Programmation Par Contraintes : démarches de modélisation pour des problÚmes d'optimisation
International audienceCet ouvrage est un vĂ©ritable guide de bonnes pratiques en Programmation par contraintes (PPC). Il dĂ©veloppe un ensemble de dĂ©marches permettant de proposer des modĂšles efficaces pour des problĂšmes d'optimisation complexes.Les outils et les raisonnements prĂ©sentĂ©s dans le livre sâadressent Ă un vaste public, dâingĂ©nieurs de chercheurs et dâĂ©tudiants.Les exemples variĂ©s analysĂ©s sont essentiellement des problĂšmes dâoptimisation de type ordonnancement / transport rĂ©alisĂ©s avec le solveur Choco. Sont prĂ©sentĂ©es pour chacun une modĂ©lisation mathĂ©matique et une modĂ©lisation PPC. Les codes proposĂ©s, et disponibles en tĂ©lĂ©chargement, ont Ă©tĂ© rĂ©alisĂ©s en Java avec l'environnement NetBeans
De la programmation linéaire à la programmation par contraintes
National audienceà destination des ingénieurs, chercheurs et étudiants formés en programmation linéaire, cet ouvrage est un guide pragmatique pour découvrir la programmation par contraintes. Au cours des chapitres, il aborde de nombreux exemples répondant à des problÚmes d'optimisation de type ordonnancement/transports:- Résolus avec Choco, proposés dans un code informatique en Java effectué avec NetBeans;- Résolus avec CPLEX, proposés dans un code informatique en C++ effectué avec Visual Studio.Sans aborder la partie théorique, cet ouvrage est une approche pratique pour se familiariser avec la programmation par contraintes
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