Search results for "Optimization"
showing 10 items of 2824 documents
Comparing reference point based interactive multiobjective optimization methods without a human decision maker
2022
AbstractInteractive multiobjective optimization methods have proven promising in solving optimization problems with conflicting objectives since they iteratively incorporate preference information of a decision maker in the search for the most preferred solution. To find the appropriate interactive method for various needs involves analysis of the strengths and weaknesses. However, extensive analysis with human decision makers may be too costly and for that reason, we propose an artificial decision maker to compare a class of popular interactive multiobjective optimization methods, i.e., reference point based methods. Without involving any human decision makers, the artificial decision make…
On Using Decision Maker Preferences with ParEGO
2017
In this paper, an interactive version of the ParEGO algorithm is introduced for identifying most preferred solutions for computationally expensive multiobjective optimization problems. It enables a decision maker to guide the search with her preferences and change them in case new insight is gained about the feasibility of the preferences. At each interaction, the decision maker is shown a subset of non-dominated solutions and she is assumed to provide her preferences in the form of preferred ranges for each objective. Internally, the algorithm samples reference points within the hyperbox defined by the preferred ranges in the objective space and uses a DACE model to approximate an achievem…
An ACT-R Based Humanoid Social Robot to Manage Storytelling Activities
2020
This paper describes an interactive storytelling system, accessible through the SoftBank robotic platforms NAO and Pepper. The main contribution consists of the interpretation of the story characters by humanoid robots, obtained through the definition of appropriate cognitive models, relying on the ACT-R cognitive architecture. The reasoning processes leading to the story evolution are based on the represented knowledge and the suggestions of the listener in critical points of the story. They are disclosed during the narration, to make clear the dynamics of the story and the feelings of the characters. We analyzed the impact of such externalization of the internal status of the characters t…
Quantitative Runge Approximation and Inverse Problems
2017
In this short note we provide a quantitative version of the classical Runge approximation property for second order elliptic operators. This relies on quantitative unique continuation results and duality arguments. We show that these estimates are essentially optimal. As a model application we provide a new proof of the result from \cite{F07}, \cite{AK12} on stability for the Calder\'on problem with local data.
Power Production from Produced Waters via Reverse Electrodialysis: A Preliminary Assessment
2022
Wastewaters generated by crude oil extraction processes, called “produced waters” (PWs), are complex solutions that contain organic compounds, mainly hydrocarbons, and often exhibit high salinity. The large amounts of PWs represent a global issue because of their environmental impact. An approach widely used in the oil industry is the reinjection of this wastewater into the extraction wells after a suitable treatment. The high salt concentration of such solutions may be used in salinity gradient technologies to produce green electricity. Among these technologies, reverse electrodialysis (RED) is one of the most promising. In this work, the application of RED for energy generatio…
The Universitary Educational System, Cibernetic System
2009
The national system of higher education shall solve one of the most difficult and most important social and human issues – the education and training of the young generation, of the labour hand. The system of higher education appears as a subsystem of the national educational system and of the society. That is why it appears the urgency of the artificial unrestriction of the university educational subsystem by the economy system. Economy’s vision of the university’s education subsystem must respond in these conditions to the following questions: What services and under what form should give the university at a time? Who should provide these services? What methods and strategies will be addr…
Towards explainable interactive multiobjective optimization : R-XIMO
2022
AbstractIn interactive multiobjective optimization methods, the preferences of a decision maker are incorporated in a solution process to find solutions of interest for problems with multiple conflicting objectives. Since multiple solutions exist for these problems with various trade-offs, preferences are crucial to identify the best solution(s). However, it is not necessarily clear to the decision maker how the preferences lead to particular solutions and, by introducing explanations to interactive multiobjective optimization methods, we promote a novel paradigm of explainable interactive multiobjective optimization. As a proof of concept, we introduce a new method, R-XIMO, which provides …
Optimal design of k-out-of-n systems
2016
The present paper is aimed at finding the best compromise to design a system k-out-of-n reliability configuration by means of the formulation of a multi-objective mathematical model. The Pareto front, which is the set of non-dominated solutions, is determined by considering the stationary availability and the achievable profit as objectives to be simultaneously optimized. The Pareto front represents a useful tool for the analyst to make the choice related to the analyzed design problem. In addition, the knowledge of the Pareto front permits to consider different design scenarios.
Chaos and its Degradation-Promoting-Based Control in an Antithetic Integral Feedback Circuit
2022
This letter deals with a novel variant of antithetic integral feedback controller (AIFC) motifs which can feature robust perfect adaptation, a pervasive (desired) ability in natural (synthetic) biomolecular circuits, when coupled with a wide class of process networks to be regulated. Using the separation of timescales in the proposed kind of AIFC, here we find a reducedorder controller that captures the governing slow part of the original solutions under suitable assumptions. Inspired by R(ossler systems, we then make use of such a simpler controller to show that the antithetic circuit can exhibit chaotic behaviors with strange attractors, where the bifurcation from a homeostatic state to c…
Shape optimization for Stokes problem with threshold slip boundary conditions
2017
This paper deals with shape optimization of systems governed by the Stokes flow with threshold slip boundary conditions. The stability of solutions to the state problem with respect to a class of domains is studied. For computational purposes the slip term and impermeability condition are handled by a regularization. To get a finite dimensional optimization problem, the optimized part of the boundary is described by B´ezier polynomials. Numerical examples illustrate the computational efficiency. peerReviewed