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The paper presents the proposed research methodology, dedicated to the application of greedy heuristics as a way of gathering information about available features. Discovered knowledge, represented in the form of generated decision rules, was employed to support feature selection and reduction process for induction of decision rules with classical rough set approach. Observations were executed over input data sets discretised by several methods. Experimental results show that elimination of less relevant attributes through the proposed methodology led to inferring rule sets with reduced cardinalities, while maintaining rule quality necessary for satisfactory classification.

7th IFAC Conference on Analysis and Design of Hybrid Systems ADHS 2021, Bruxelles, BELGIQUE, 07-/07/2021 - 09/07/2021; In this paper, we introduce a hybridization-based feedback control synthesis method for potentially unstable nonlinear continuous-time systems. We construct a discretization and feedback control that ensures dissipation form of incremental input-to-state stability property that a number of abstraction-based control methods rely on or benefit from. This enables the use of these methods also for the case of potentially unstable systems, to achieve a reachability or a temporal logic specification. We furthermore show that the algorithm can also improve abstraction-based methods that do not rely on stability assumptions by reducing the number of constructed abstract states and non-deterministic transitions. We illustrate the benefits of our approach in simulations featuring a cart-pendulum.

In this article, we provide sufficient conditions under which the controlled vector fields solution of optimal control problems formulated on continuity equations are Lipschitz regular in space. Our approach involves a novel combination of mean-field approximations for infinite-dimensional multi-agent optimal control problems, along with a careful extension of an existence result of locally optimal Lipschitz feedbacks. The latter is based on the reformulation of a coercivity estimate in the language of Wasserstein calculus, which is used to obtain uniform Lipschitz bounds along sequences of approximations by empirical measures.

23rd International Conference on Knowledge-Based and Intelligent Information & Engineering Systems - early article, The paper presents research on unsupervised and supervised discretisation of input data used in execution of stylometric tasks of authorship attribution. Basing on numeric characterisation of writing styles, recognition of authorship is performed by decision rules, as their transparent structure enhances understanding of discovered knowledge. The performance of rule classifiers, constructed in rough set approach, is studied in the context of a strategy employed for resolving conflicts. It is also contrasted with that of other selected inducers.

peer-reviewed The full text of this article will not be available in ULIR until the embargo expires on the 17/04/2020 Building energy simulations have found widespread use as decision-making tools for determining design and retrofitting actions. Despite their popularity, there exists a well-reported issue regarding the numerical treatment of structural thermalstorage components in these models. The optimal means of discretising multi-layer structures is complicated by the different thermo-physical properties, material configurations and boundary conditions encountered within building energy models. This paper addresses this information gap by proposing a methodology that can be universally applied to all multi-layer structures, ensuring accurate predictions while avoiding excessive computational cost. Governing dimensionless quantities of Biot and Fourier numbers are utilised within the discretisation process, making the methodology equally applicable to all materials. The presented methodology also accounts for the configuration of materials within multi-layer structures when assigning discretisation levels, leading to nodes being distributed in accordance with expected thermal gradients. The proposed discretisation methodology has been examined for a number of boundary conditions and wall types with excellent prediction accuracy achieved throughout. Additionally, the utility of resistance-only layers has been explored as a means of increasing computational efficiency. This highlighted the importance of considering both layer position and local thermal properties when simulating multi-layer structures.

peer-reviewed Improving building energy efficiency is of paramount importance due to the large proportion of energy consumed by thermal operations. Consequently, simulating a building's environment has gained popularity for assessing thermal comfort and design. The extended timeframes and large physical scales involved necessitate compact modelling approaches. The accuracy of such simulations is of chief concern, yet there is little guidance offered on achieving accurate solutions whilst mitigating prohibitive computational costs. Therefore, the present study addresses this deficit by providing clear guidance on discretisation levels required for achieving accurate but computationally inexpensive models. This is achieved by comparing numerical models of varying discretisation levels to benchmark analytical solutions with prediction accuracy assessed and reported in terms of governing dimensionless parameters, Biot and Fourier numbers, to ensure generality of findings. Furthermore, spatial and temporal discretisation errors are separated and assessed independently. Contour plots are presented to intuitively determine the optimal discretisation levels and time-steps required to achieve accurate thermal response predictions. Simulations derived from these contour plots were tested against various building conditions with excellent agreement observed throughout. Additionally, various scenarios are highlighted where the classical single lumped capacitance model can be applied for Biot numbers much greater than 0.1 without reducing accuracy.

A Rotationally Symmetric Spherical Discretisation (RSSD) technique has recently been developed for the discretisation of scattering phase functions in the Discrete Ordinates Method (DOM) in a consistent and rational manner. RSSD has inherent energy conservation, is suitable for any quadrature scheme used, minimising run-time matrix calculation, and to date has been used for the S4, S6 and S8 ordinate sets. In this follow-up paper, the RSSD boundary intervals for the four weightings of the S10 ordinate set are presented. The effect of asymmetry factor g and angular resolution of the discrete input scattering phase function distribution “grid” on final RSSD errors (in scattered energy conservation and calculated asymmetry factor) is explored, making use of the Henyey–Greenstein (HG) family of distributions. It is shown that the RSSD scattered energy error View the MathML sourceξeRSSD is a strong function of the grid resolution, indicating that View the MathML sourceξeRSSD can be controlled down to user-required levels by judicious choice of grid resolution and by local grid refinement in regions of steep gradients and peaks in the scattering phase function distribution (in this paper error levels as low as 0.002% have been achieved). RSSD asymmetry factor error View the MathML sourceξgRSSD behaves differently to View the MathML sourceξeRSSD, however, displaying a strong grid resolution dependence in a “grid sensitivity zone” of combinations of coarse grid resolution and high values of prescribed g (for the HG family of scattering phase functions, above g values of 0.9, 0.95 and 0.98 for grid angular resolutions of 1°, 0.5° and 0.25° respectively). Outside of the “grid sensitivity zone” g error is insensitive to grid resolution and achieves maximum (positive and negative) values of between −2.7% and 1% between prescribed g values of 0.7 and 0.9. This band decreases to a range from −1% to 1% for the S4, S6 and S10 ordinate sets. The grid resolution conclusions are supported by examining RSSD discretisation for two real scattering phase function distributions: for a diffusely reflecting large sphere with an asymmetry factor of −0.4444, grid angular resolutions of 2°, 1°, 0.5° and 0.25° resulted in the decreasing maximum View the MathML sourceξeRSSD values of 0.0449%, 0.0136%, −0.0050% and −0.0015% respectively, but near-constant maximum View the MathML sourceξgRSSD values of −1.225%, −1.239%, −1.247% and −1.250% respectively, while for a transparent large sphere with an asymmetry factor of 0.660, grid angular resolutions of 1°, 0.5° and composite 0.5°/0.25° resolution resulted in the decreasing maximum View the MathML sourceξeRSSD values of 0.0685%, −0.0402% and −0.0046% respectively and near-constant maximum View the MathML sourceξgRSSD values of −1.286%, −1.310% and −1.313% respectively

[EN] Recently, Unmanned Aerial Vehicles (UAVs) have become a cheap alternative to sense pollution values in a certain area due to their flexibility and ability to carry small sensing units. In a previous work, we proposed a solution, called Pollution-driven UAV Control (PdUC), to allow UAVs to autonomously trace pollutant sources, and monitor air quality in the surrounding area. However, despite operational, we found that the proposed solution consumed excessive time, especially when considering the battery lifetime of current multi-rotor UAVs. In this paper, we have improved our previously proposed solution by adopting a space discretization technique. Discretization is one of the most efficient mathematical approaches to optimize a system by transforming a continuous domain into its discrete counterpart. The improvement proposed in this paper, called PdUC-Discretized (PdUC-D), consists of an optimization whereby UAVs only move between the central tile positions of a discretized space, avoiding monitoring locations separated by small distances, and whose actual differences in terms of air quality are barely noticeable. We also analyze the impact of varying the tile size on the overall process, showing that smaller tile sizes offer high accuracy at the cost of an increased flight time. Taking into account the obtained results, we consider that a tile size of 100 x 100 meters offers an adequate trade-off between flight time and monitoring accuracy. Experimental results show that PdUC-D drastically reduces the convergence time compared to the original PdUC proposal without loss of accuracy, and it also increases the performance gap with standard mobility patterns such as Spiral and Billiard., This work was partially supported by the "Programa Estatal de Investigacion, Desarrollo e Innovacion Orientada a Retos de la Sociedad, Proyecto I+D+I TEC2014-52690-R", the framework of the DIVINA Challenge Team, which is funded under the Labex MS2T program. Labex MS2T is supported by the French Government, through the program "Investments for the future" managed by the National Agency for Research (Reference: ANR-11-IDEX-0004-02), the "Programa de becas SENESCYT de la Republica del Ecuador", and the Research Direction of the University of Cuenca.

Multiple uncertainties complicate socio-economic forecasting problems, especially when relying on ill-conditioned limited data. Such problems are best addressed by grey prediction models such as Grey Verhulst Model (GVM). This paper resolves the incompatibility between GVM’s estimation and prediction by taking its basic form equation as the basis of both. The resultant “Basic Form”-focused GVM (BFGVM) is also further developed to create Direct Non-equidistant BFGVM (DNBFGVM) and, in turn, DNBFGVM with Recursive simulation (DNBFGVMR). Experimental analyses comprise 19 socio-economic time series with an emphasis on Iranian population, a low-frequency non-equidistant time series with remarkable strategic importance. Promisingly, the proposed DNBFGVM and DNBFGVMR provide accurate in-sample and out-of-sample socio-economic forecasts, show highly significant improvements over the best traditional GVM, and offer cost-effective intelligent support of decision-making. Final results suggest future trends of studied socio-economic time series. Specifically, they reveal Iranian population to grow even slower than anticipated, demanding an urgent consideration of policy-makers.

[Departement_IRSTEA]Eaux [TR1_IRSTEA]ARCEAU; Distributed hydrological models are valuable tools that can be used to support water management in catchments. However, the complexity of management issues, the variety of modelling objectives, and the variable availability of data require a flexible way to customize models and adapt them to each individual problem. Environmental modelling frameworks offer such flexibility; they are designed to build and run integrated models on the basis of reusable and exchangeable components. This paper presents the LIQUID® framework, developed by Hydrowide since 2005. The purpose of developing LIQUID® was to provide both easier integration of hydrological processes and preservation of their characteristic temporal and spatial scales. It suits a wide range of applications, both in terms of spatial scales and of process conceptualisations. LIQUID® is able to synchronize different time steps, to handle irregular geometries, and to simulate complex connections between components, in particular involving feedback. The paper presents the concepts of LIQUID® and the technical choices made to meet the above requirements, with focuses on the simulation run system and on the spatial discretization of process components. The use of the framework is illustrated by five application cases associated with contrasted spatial and temporal scales.

Lien vers l’application : http://demomed.org/index.php/fr/ Pour comprendre les interactions demographiques, sociales et familiales en Mediterranee dans une perspective comparative et a des niveaux infranationaux, les donnees empiriques sur lesquelles s’appuient les analyses sociologiques sont soumises a plusieurs exigences. Elles doivent etre non seulement fines et de qualite, mais souvent spatialisees et datees afin de suivre et comprendre les evolutions temporelles et les dynamiques en cour...