Surrogate models are often used to reduce the cost of design optimization problems that involve computationally costly models, such as computational fluid dynamics simulations. However, the number of evaluations required by surrogate models usually scales poorly with the number of design variables, and there is a need for both better constraint formulations and multimodal function handling. To address this issue, we developed a surrogate-based gradient-free optimization algorithm that can handle cases where the function evaluations are expensive, the computational budget is limited, the functions are multimodal, and the optimization problem includes nonlinear equality or inequality constraints. The proposed algorithm-super efficient global optimization coupled with mixture of experts (SEGOMOE)can tackle complex constrained design optimization problems through the use of an enrichment strategy based on a mixture of experts coupled with adaptive surrogate models. The performance of this approach was evaluated for analytic constrained and unconstrained problems, as well as for a multimodal aerodynamic shape optimization problem with 17 design variables and an equality constraint. Our results showed that the method is efficient and that the optimum is much less dependent on the starting point than the conventional gradient-based optimization.
The IUCN Green List of Protected and Conserved Areas is the first global sustainability standard describing best practice for area-based conservation. The standard is organised around four components-Good Governance, Sound Design and Planning, Effective Management and Successful Conservation Outcomes-subdivided into 17 criteria and 50 indicators. IUCN manages a 'Green List' of protected and conserved areas through a certification process that examines evidence assembled by site managers against each of the criteria and indicators. The assessment of evidence is carried out by an independent group of experts in the governance and management of protected and conserved areas, overseen by an independent reviewer to ensure that proper processes and appropriate evidence are used in the assessment. The objective of the IUCN Green List programme is to increase the number of protected and conserved areas around the world that deliver successful conservation outcomes through good governance, sound design and effective and equitable management. The IUCN Green List programme is currently operating in 40 countries and by August 2019, 46 sites in 14 countries had been awarded the Green List status. There are a further 400+ protected and conserved areas engaged in the process. The challenge remains to scale up the Green List programme to the point where it is truly global in operation and able to provide both a stimulus and a metric for effective conservation.
This paper presents methodological investigations performed in research activities in the field of MDO in overall aircraft design in the ongoing EU funded research project AGILE. AGILE is developing the next generation of aircraft Multidisciplinary Design and Optimization processes, which target significant reductions in aircraft development costs and time to market, leading to cheaper and greener aircraft solutions. The paper introduces the AGILE project structure and describes the achievements of the 1st year (Design Campaign 1) leading to a reference distributed MDO system. A focus is then made on the different novel optimization techniques studied during the 2nd year, all willing to ease the optimization of complex work flows, characterized by high degree of discipline interdependencies, high number of design variables in the context of multi-level and multi-partner collaborative engineering projects. Then the implementation of these methods in the enhanced MDO framework is discussed
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.