Optimal viable path search for a cheese ripening process using a multi-objective EA.

International audienceViability theory is a very attractive theoretical approach for the modeling of complex dynamical systems. However, its scope of application is limited due to the high computational power it necessitates. Evolutionary computation is a convenient way to address some issues related to this theory. In this paper, we present a multi-objective evolutionary approach to address the optimisation problem related to the computation of optimal command profiles of a complex process. The application we address here is a real size problem from dairy industry, the modeling of a Camembert cheese ripening process. We have developed a parallel implementation of a multiobjective EA that has produced a Pareto front of optimal control profiles (or trajectories), with respect to four objectives. The Pareto front was then analysed by an expert who selected a interesting compromise, yielding a new control profile that seems promising for industrial applications

Utilisation de EGI par la communauté des modélisateurs en systèmes complexes

International audienceUtilisation de EGI par la communauté des modélisateurs en systèmes complexe

Viabilitree: A kd-tree Framework for Viability-based Decision

The mathematical viability theory offers concepts and methods that are suitable to study the compatibility between a dynamical system described by a set of differential equations and constraints in the state space. The result sets built during the viability analysis can give very useful information regarding management issues in fields where it is easier to discuss constraints than objective functions. However, computational problems arise very quickly with the number of state variables, and the practical implementation of the method is difficult, although there exists a convergent numerical scheme and several approaches to bypass the computational problems. In order to popularize the use of viability analysis we propose a framework in which the viability sets are represented and approximated with particular kd-trees. The computation of the viability kernel is seen as an active learning problem. We prove the convergence of the algorithm and assess the approximation it produces for known problems with analytical solution. This framework aims at simplifying the declaration of the viability problem and provides useful methods to assist further use of viability sets produced by the computation

OpenMOLE, a workflow engine specifically tailored for the distributed exploration of simulation models

International audienceComplex-systems describe multiple levels of collective structure and organization. In such systems, the emergence of global behaviour from local interactions is generally studied through large scale experiments on numerical models. This analysis generates important computation loads which require the use of multi-core servers, clusters or grid computing. Dealing with such large scale executions is especially challenging for modellers who don't possess the theoretical and methodological skills required to take advantage of high performance computing environments. That's why we have designed a cloud approach for model experimentation. This approach has been implemented in OpenMOLE (Open MOdel Experiment) as a Domain Specific Language (DSL) that leverages the naturally parallel aspect of model experiments. The OpenMOLE DSL has been designed to explore user-supplied models. It delegates transparently their numerous executions to remote execution environment. From a user perspective, those environments are viewed as services providing computing power, therefore no technical detail is ever exposed. This paper presents the OpenMOLE DSL through the example of a toy model exploration and through the automated calibration of a real-world complex system model in the field of geography

7th International ISEKI-Food Conference: next-generation of food research, education and industry. Book of abstracts

As part of its mission, ISEKI-Food Association establishes and maintains a network among universities, research institutions, and companies in the food chain in addition to working to ensure that food studies are of high quality. However, we must also begin planning how to gear science, education, and the food industry to meet the needs of future generations as well as how to contribute to the sustainability of our planet by these food actors. In light of this, the 7th International ISEKI-Food Conference, which had as main theme “NEXT-GENERATION OF FOOD RESEARCH, EDUCATION AND INDUSTRY”, focused on future challenges in education on food science and technology, in research activities related to processing, quality and safety, packaging of foods and in societal engagements in the field divided in three main sections: EDUCATION: CHALLENGES OF EDUCATION IN A CHANGING WORLD; RESEARCH: NEXT GENERATION OF FOODS; and SOCIETY ENGAGEMENT: SOCIETY AND FOOD INDUSTRY. The conference was dedicated to all food actors, creating bridges among them. The delegates had the opportunity to exchange new ideas and experiences face to face, to establish business or research relations, and find global partners for future collaborations.info:eu-repo/semantics/publishedVersio

Evaluation and Exploration of Microbial Quality and Safety Aspects of Unpasteurized Retail Maine Dairy Products

The Dietary Guidelines for Americans recommend dairy products as part of a healthy diet and these products are significant contributors of important nutrients. In the U.S., and Maine specifically, demand for locally-produced, minimally processed foods, including unpasteurized dairy, has increased during the past several decades. An analysis of retrospective microbial testing data for unpasteurized retail dairy products revealed increasing microbial quality from 1998-2016, despite a five-fold increase in sample numbers during this time. Higher percentages of samples were non-compliant with microbial quality standards during the summer months compared to winter. High coliform counts were the leading cause of non-compliant samples in milks and other dairy-based products. The second objective of this research was to investigate the effects of cheesemaking and aging temperature on levels of inoculated foodborne pathogens. The cheesemaking process did not affect the populations of either pathogen of interest. During aging, lower temperatures (4℃ and 10℃) significantly decreased population of Shiga-toxigenic E. coli, whereas only 4℃ significantly reduced L. monocytogenes. Aging at 4℃ was also effective in maintaining the population of the starter culture. The highest aging temperature (22℃) caused a significant increase of both pathogens as well as a significant increase in pH levels and softening of the cheese texture. In tests of unpasteurized retail dairy products, the highest rates of presumptive positive results for Listeria spp. were recorded in July and August. The prevalence of presumptive positive Listeria spp. was higher in mold-ripened compared to soft cheeses. There was a significant positive correlation between non-compliant levels of coliforms and presence of presumptive positive Listeria spp. in the samples tested. The results of this research suggest that the overall quality of the expanding unpasteurized dairy sector in Maine has remained constant or improved in the past two decades. Small-scale cheese operations participating in this market should use refrigeration temperatures for aging of cheese when possible, which will provide the best control against foodborne pathogens. Finally, more targeted testing techniques are suggested to detect the potential sources of coliforms and to ensure the safety of unpasteurized dairy commodities

Functional Coatings for Food Packaging Applications

The food packaging industry is experiencing one of the most relevant revolutions associated with the transition from fossil-based polymers to new materials of renewable origin. However, high production costs, low performance, and ethical issues still hinder the market penetration of bioplastics. Recently, coating technology was proposed as an additional strategy for achieving a more rational use of the materials used within the food packaging sector. According to the packaging optimization concept, the use of multifunctional thin layers would enable the replacement of multi-layer and heavy structures, thus reducing the upstream amount of packaging materials while maintaining (or even improving) the functional properties of the final package to pursue the goal of overall shelf life extension. Concurrently, the increasing requirements among consumers for convenience, smaller package sizes, and for minimally processed, fresh, and healthy foods have necessitated the design of highly sophisticated and engineered coatings. To this end, new chemical pathways, new raw materials (e.g., biopolymers), and non-conventional deposition technologies have been used. Nanotechnology, in particular, paved the way for the development of new architectures and never-before-seen patterns that eventually yielded nanostructured and nanocomposite coatings with outstanding performance. This book covers the most recent advances in the coating technology applied to the food packaging sector, with special emphasis on active coatings and barrier coatings intended for the shelf life extension of perishable foods