Parallel machine scheduling with precedence constraints and setup times

This paper presents different methods for solving parallel machine scheduling problems with precedence constraints and setup times between the jobs. Limited discrepancy search methods mixed with local search principles, dominance conditions and specific lower bounds are proposed. The proposed methods are evaluated on a set of randomly generated instances and compared with previous results from the literature and those obtained with an efficient commercial solver. We conclude that our propositions are quite competitive and our results even outperform other approaches in most cases

An interdisciplinary method for a generic vehicle routing problem decision support system

International audienceIn this paper, we propose an interdisciplinary method for the logistics of transportation. It focuses on the design of a generic architecture for the vehicle routing problem (VRP). We highlight that human factors and dynamics aspects are generally ignored in the classical approaches to solve the vehicle routing problem. In our study, a link is done between methods of operations research (specific methods to solve vehicle routing problems and constraint programming techniques) and a work domain analysis technique coming from cognitive ergonomics. The proposed architecture allows to consider and to process the constraints identified by the work domain analysis during the problem resolution. It is also well adapted to the consideration of the Human as a main actor in the decision-making process

Analyse du domaine de travail pour les problèmes de tournées de véhicules

Cet article s'inscrit dans une démarche de proposition d'une approche interdisciplinaire appliquée à la logistique des transports. On s'intéresse plus particulièrement à la conception d'une architecture générique pour le problème de tournées de véhicules (VRP). On propose ainsi une articulation entre des méthodes de recherche opérationnelle (principalement la programmation par contraintes) et une analyse du domaine de travail issue de l'ergonomie cognitive

Scheduler-oriented algorithms to improve human-machine cooperation in transportation scheduling support systems

International audienceA decision support system designed to enhance human-machine interaction in transportation scheduling is proposed. We aim to integrate human factors and ergonomics from the beginning of the design phase and to propose a system fitted with enough flexibility to be able to deal with the characteristics of a dynamic context such as transportation scheduling. In this interdisciplinary approach, a link is done between problem solving methods (operations research techniques and data classification algorithms) and human-machine interaction (solving control modes). A set of scheduler-oriented algorithms favouring human-machine cooperation for problem solving is proposed. Some of these algorithms have been efficiently tested on instances of the literature. Finally, an original framework aiming to assist scheduler in constraint relaxation when the problem becomes infeasible is proposed and evaluated

Work domain analysis and ecological interface for the vehicle routing problem

International audienceIn this paper, we propose a work domain analysis for the vehicle routing problem. This analysis facilitates the identification of the problem constraints. The analysis is done through an abstraction hierarchy which facilitates an ecological user-interface design. The proposed decision support system and the ecological interfaces are presented. Finally, we propose an experimental study in order to evaluate the influence on the user for one of these interfaces

Implications of technological changes in vehicle routing interfaces for planners' constraint processing

International audienceThis study sought to assess the consequences of technological changes in vehicle routing interfaces for planners' constraint processing during route selection. We began by developing a model of domain constraints for the generic vehicle routing problem, in order to characterize planners' constraint processing and assess the visibility of constraints on different routing interfaces. An experiment featuring vehicle routing problems was then designed to test interfaces reflecting technological changes, including automation leading to simplified interfaces and the display of multiple routes computed by algorithms. Twelve participants who had worked for a small transport company for nine months were exposed to all these interfaces. Mental workload, performance and decision-making times were measured. Results revealed that automation decreases mental workload and decision times, attributable to the abridged (vs. unabridged) display of constraints on the interface. Results also showed that the perceptual (vs. analytical) display of routes greatly decreases decision times and enhances performances

A decision support system for vehicle routing based on model inversion and data analysis

International audienceIn this paper, we present a three-phase solving mechanism for the vehicle routing problem. The solving mechanism is part of a decision support system architecture deduced from an interdisciplinary study. We highlight that human factors and dynamic aspects are generally ignored in the classical approaches to solve the problem. In our approach, a link is done between methods of operations research and an ecological interface design coming from cognitive ergonomics. We focus our study in how to manage the constraint relaxation if the problem is not satisfiable. We propose and evaluate model inversion techniques and data classification based methods in order to determine the most suitable constraints to relax in priority

Une approche interdisciplinaire pour l'ordonnancement des transports

Dans cette thèse, nous proposons d’aborder l’ordonnancement des transports par une approche interdisciplinaire. L’idée est d’intégrer les facteurs humains dans le système d’aide à la décision réalisé, de façon à ce que l’homme puisse agir sur la modélisation et la résolution du problème. Le système proposé doit offrir de la flexibilité, afin d’être capable de s’adapter aux nouvelles situations et aux changements, même si ceux-ci n’ont pas été prévus initialement par le concepteur du système. Pour atteindre l’objectif fixé, nous nous sommes notamment appuyé sur une analyse du domaine de travail (« Work Domain Analysis ») basée sur une hiérarchie d’abstraction des entités (physiques ou plus abstraites) manipulées dans ce type de problèmes. Nous avons proposé une architecture pour le système d’aide à la décision basée sur cette analyse du domaine et la programmation par contraintes. Nous avons également conçu, et intégré dans le système, des algorithmes dédiés et des méthodes de résolution basés sur le principe d’inversion de modèle. Enfin, nous avons proposé une architecture d’interfaces avec l’objectif d’assister efficacement l’opérateur humain dans la réalisation des différentes sous-tâches nécessaires à la résolution globale du problème. L’étude du sujet interdisciplinaire a été précédée d’une analyse focalisée sur la résolution de problèmes théoriques d’ordonnancement à machines parallèles avec contraintes de précédence et temps de préparation des machines entre opérations, utilisant des méthodes de recherche arborescente basée sur les divergences.An interdisciplinary approach has been proposed for the vehicle routing problem. The idea is to consider human factors and dynamic aspects for the decision support system (DSS) design. In our approach, a link is done between methods of operations research and an ecological interface design coming from engineering cognitive. A work domain analysis for the vehicle routing problem has been done. The analysis is realized through an abstraction hierarchy, which facilitates the identification of the problem constraints. We have proposed a DSS architecture based on this analysis and on constraint programming. Specific algorithms and solving mechanisms based on model inversion have been proposed and integrated in the system. Finally, we have design a set of human-machine interfaces in order to facilitate the problem solving to the human planning. The interdisciplinary study has been preceded by an analysis of the parallel machine scheduling problem with precedence constraints and setup times. Tree searches and local searches based on limited discrepancy search have been proposed to solve the problem

Pulverized Water Hyacinth as an Admixture for Concrete

This study sought to evaluate the setting time and strength property of concrete when pulverized water hyacinth serves as an admixture by weight. The materials used in this study included water hyacinth plants, cement, coarse and fine aggregates. Dried water hyacinth was pulverized and added to the concrete with two different percentages in each mixture. A standard mixture without water hyacinth was also created for comparison with the concrete cylinders with mixture that has pulverized water hyacinth. The first concrete cylinder contains 0.5% of pulverized water hyacinth by weight and the second concrete cylinder contains 1% of pulverized water hyacinth by weight. The curing was done for 28 days, and the properties of the concrete cylinders, namely setting time and strength, were recorded.  It was revealed in the setting time test that the concrete with 0.5% pulverized water hyacinth may serve as accelerator for concrete while the concrete cylinder with 1% pulverized water hyacinth by weight can be a retarder. Moreover, the concrete cylinders with water hyacinth have better compressive strength than that of the concrete cylinder without pulverized water hyacinth

FOXO1 represses PPARα-Mediated induction of FGF21 gene expression

Fibroblast growth factor 21 (FGF21) has emerged as a metabolic regulator that exerts potent anti-diabetic and lipid-lowering effects in animal models of obesity and type 2 diabetes, showing a protective role in fatty liver disease and hepatocellular carcinoma progression. Hepatic expression of FGF21 is regulated by PPARa and is induced by fasting. Ablation of FoxO1 in liver has been shown to increase FGF21 expression in hyperglycemia. To better understand the role of FOXO1 in the regulation of FGF21 expression we have modified HepG2 human hepatoma cells to overexpress FoxO1 and PPARa. Here we show that FoxO1 represses PPARa-mediated FGF21 induction, and that the repression acts on the FGF21 gene promoter without affecting other PPARa target genes. Additionally, we demonstrate that FoxO1 physically interacts with PPARa and that FoxO1/3/4 depletion in skeletal muscle contributes to increased Fgf21 tissue levels. Taken together, these data indicate that FOXO1 is a PPARa-interacting protein that antagonizes PPARa activity on the FGF21 promoter. Because other PPARa target genes remained unaffected, these results suggest a highly specific mechanism implicated in FGF21 regulation. We conclude that FGF21 can be specifically modulated by FOXO1 in a PPARa-dependent manner. (c) 2023 The Authors. Published by Elsevier Inc. This is an open access article under the CC BY-NC license (http://creativecommons.org/licenses/by-nc/4.0/).info:eu-repo/semantics/publishedVersio