A proposal for particles' initialization in PSO is presented and discussed, with focus on costly global unconstrained optimization problems. The standard PSO iteration is reformulated such that the trajectories of the particles are studied in an extended space, combining particles' position and speed. To the aim of exploring effectively and efficiently the optimization search space since the early iterations, the particles are initialized using sets of orthogonal vectors in the extended space (orthogonal initialization, ORTHOinit). Theoretical derivation and application to a simulation-based optimization problem in ship design are presented, showing the potential benefits of the current approach.

. A guideline for an effective and efficient use of a deterministic variant of the Particle Swarm Optimization (PSO) algorithm is presented and discussed, assuming limited computational resources. PSO was introduced in Kennedy and Eberhart (1995) and successfully applied in many fields of engineering optimization for its ease of use. Its performance depends on three main characteristics: the number of swarm particles used, their initialization in terms of initial location and speed, and the set of coefficients defining the behavior of the swarm. Original PSO makes use of random coefficients to sustain the variety of the swarm dynamics, and requires extensive numerical campaigns to achieve statistically convergent results. Such an approach can be too expensive in industrial applications, especially when CFD simulations are used, and for this reason, efficient deterministic approaches have been developed (Campana et al. 2009). Additionally, the availability of parallel architectures has offered the opportunity to develop and compare synchronous and asynchronous implementation of PSO. The objective of present work is the identification of the most promising implementation for deterministic PSO. A parametric analysis is conducted using 60 analytical test functions and three different performance criteria, varying the number of particles, the initialization of the swarm, and the set of coeffi- cients. The most promising PSO setup is applied to a ship design optimization problem, namely the high-speed Delft catamaran advancing in calm water at fixed speed, using a potential-flow code.

Deterioration of stones is a complex problem and one of the main concern for people working in the field of conservation and restoration of cultural heritage. One important point in cultural heritage is to obtain information about the damage in a non-invasive way. By this paper, we propose a new non-invasive tool that permits evaluation of the thickness of (Formula presented.) (gypsum) grown (sulfation) on marble stones, using a mathematical model on data detected by pulsed infrared thermography.

L'applicazione di algoritmi di ottimizzazione nella navigazione a vela in Coppa America. Ce ne parla Daniele Peri dell'Iac-Cnr.

We developed an approach that integrates different network-based methods to analyze the correlation network arising from large-scale gene expression data. By studying grapevine (Vitis vinifera) and tomato (Solanum lycopersicum) gene expression atlases and a grapevine berry transcriptomic data set during the transition from immature to mature growth, we identified a category named “fight-club hubs” characterized by a marked negative correlation with the expression profiles of neighboring genes in the network. A special subset named “switch genes” was identified, with the additional property of many significant negative correlations outside their own group in the network. Switch genes are involved in multiple processes and include transcription factors that may be considered master regulators of the previously reported transcriptome remodeling that marks the developmental shift from immature to mature growth. All switch genes, expressed at low levels in vegetative/green tissues, showed a significant increase in mature/woody organs, suggesting a potential regulatory role during the developmental transition. Finally, our analysis of tomato gene expression data sets showed that wild-type switch genes are downregulated in ripening-deficient mutants. The identification of known master regulators of tomato fruit maturation suggests our method is suitable for the detection of key regulators of organ development in different fleshy fruit crops.

This paper presents an approach to model and simulate industrial plant accidents as well as the related emergency management; interoperable simulation is proposed as approach for applying High Level Architecture in this context. The authors are focusing their attention on the disaster simulation and its interaction with the emergency management. Modern simulation, by using technology enables such as mobile solution, enhance its support to first responders, the dynamic reaction to crisis evolution as well as the improvement in training and management of safe routing and handling of injured people. This paper introduces these elements as part of new research track devoted to get benefits from interoperable simulation in federating multidisciplinary models for industrial plant emergency management.

The regularized lattice BGK (RLBGK) is validated against high-accuracy spectral Chebyshev methods for lid-driven cavity flows. RLBGK is shown to provide a viable alternative to standard lattice BGK schemes, with significant enhancement of numerical stability at a very moderate computational extra-cost. © 2014 World Scientific Publishing Company.

A conference on the occasion of the 60th birthday of Maurizio Falcone

Bioventing is a technology used to abate the presence of pollutants in the subsoil. Microorganisms biodegrade the pollutant but the biochemical reaction requires oxygen and so an air ow is induced in the subsoil by means of injection and/or extraction wells. Costs, final result and decontamination time are reliant on contaminant type, soil permeability and several other factors, but oxygen subsoil concentration plays a very important role. For this reason a rational choice of well location and ow rate is required. The mathematical definition of the optimal design problem will be setup starting from a simplified mathematical model describing the bioventing system. A formal definition of decontaminated subsoil will be given and the set of system control variables will be identified. Several optimimization strategies such as cost minimization, removal rate maximization and time optimization will be mathematically described.

Bioventing is a clean-up technology essentially used to remove hydrocarboon from polluted subsoil by the action of microorganism. The model is based on the theory of fluid flows in porous media and on the mathematical description of population dynamics. The numerical results of a simplified model will be described.

The nucleation mechanisms of methane hydrates are studied using well-tempered metadynamics and restrained molecular dynamics. The collective variables we used to follow the process are the methane-methane and methane-water coordination numbers, from which we computed the corresponding Landau free energy surface. This surface is characterized by two minima, corresponding to the two-phase methane bubble/water solution and clathrate crystal, and a transition state. The clathrate crystal is of type II, while in the simulation conditions (T = 273 K and P = 500 atm) the most stable phase should be type I. We constructed the steepest ascent/descent path connecting the two-phase methane bubble/water solution to the clathrate state and passing through the transition state. We interpret this path as the nucleation path, which shows four phases. First, the concentration of solvated methane increases in the aqueous domain via diffusion through the methane-water interface. Second units of methane molecules solvated in water meet to form an unstructured cluster. Third, the water content of the nucleus decreases to a value compatible with the type II methane clathrate hydrate composition. Finally, a reordering process of solvated methane and water molecules occurs in a manner consistent with the "blob" hypothesis (Jacobson, L. C.; Hujo, W.; Molinero, V. J Am. Chem. Soc. 2010, 132, 11806-11811).

The formation of methane-hydrate precursors at large planar water-methane interfaces has been studied using massively parallel molecular dynamics in systems of varying size from around 10 000 to almost 7 x 10(6) molecules. This process took two distinct steps. First, the concentration of solvated methane clusters increases just inside the aqueous domain via slow diffusion from the methane-water interface, forming "clusters" of solvated methane molecules. Second, the re-ordering process of solvated methane and water molecules takes place in a manner very roughly consistent with the "blob" hypothesis, although with important differences, to form hydrate precursors, necessary for subsequent hydrate nucleation and crystallisation. It was found that larger system sizes serve to promote the formation rate of precursors. (C) 2014 AIP Publishing LLC.

In this study, the immersed boundary-thermal lattice Boltzmann method has been used to simulate non-Newtonian fluid flow over a heated circular cylinder. The direct-forcing algorithm has been employed to couple the off-lattice obstacles and on-lattice fluid nodes. To investigate the effect of boundary sharpness, two different diffuse interface schemes are considered to interpolate the velocity and temperature between the boundary and computational grid points. The lattice Boltzmann equation with split-forcing term is applied to consider the effects of the discrete lattice and the body force to the momentum flux, simultaneously. A method for calculating the Nusselt number based on diffuse interface schemes is developed. The rheological and thermal properties of non-Newtonian fluids are investigated under the different power-law indices and Reynolds numbers. The effect of numerical parameters on the accuracy of the proposed method has been investigated in detail. Results show that the rheological and thermal properties of non-Newtonian fluids in the presence of a heated immersed body can be suitably captured using the immersed boundary thermal lattice Boltzmann method.

The ESA-ESRIN contract no. 21719/08/I-OL covered the activities performed between April 2008 and July 2014 by the L2 sub-group of the MIPAS Quality Working Group. The main objective of this project was to monitor the quality of MIPAS L2 products, to improve the performances of the L2 ESA processor, used for both the near real time analysis during ENVISAT mission and for the off-line analysis, and to enlarge the list of retrieved species. In particular, three different versions of the MIPAS operational processor were finalized: IPF V5, ML2PP V6 and ML2PP V7, leading to significant improvements in the quality of the products and in their diagnostics, to an increase of the number of processed scans, and to an enlargement of the list of provided products. With respect to IPF V4.1&2, used to process only the first two years of MIPAS measurements (2002-2004, Full Resolution (FR) measurements) and validated with respect to correlative measurements (Ridolfi et al., 2006, Cortesi et al., 2007, Wang et al., 2007, Payan et al., 2009, Wetzel et al., 2007, Wetzel et al., 2013, all contained in the MIPAS special issue), IPF V5: o performs the analysis of the full mission (both FR and Optimized Resolution (OR) measurements, characterized by a reduced spectral resolution but finer spatial resolution) after the introduction of an a posteriori regularization with self-adapting threshold aimed to reduce instabilities of the retrieval with measurements of the OR phase (due to sampling intervals finer than the instantaneous field of view of the instrument and the choice of using a retrieval grid aligned with the vertical sampling of the measurements); o provides as output Averaging Kernel (AK) for each scan. Products of ML2PP V6 are very similar to the ones of V5 in terms of bias, but are characterized by: o an improved diagnostics, since the Covariance Matrix and the AK matrix are computed taking into account all iterations performed during the retrieval (this is needed if the final Marquardt parameter is different from zero). Furthermore, horizontal AKs are provided for each latitude band and each season. o additional four new species, namely CFC-11, CFC-12, N2O5 and ClONO2. MIPAS ESA processor products V7 are characterized by: o reduced time dependent calibration error due to non-linearities (coming from using new L1 data, V7); o availability of retrieval altitude grid characterized by a very small bias after correction with ECMWF pressure/altitude relationship; o new microwindows for FR measurements with an increased information content and leading to a reduction of the detected bias in the FR measurements for CH4, N2O and CFC-12; o larger stability, given by the new approach for retrieving continuum (the continuum transmission is fitted instead of the continuum cross-section), and new regularization with altitude dependent regularization strength; o lower bias of CFC-11, due to proper handling of COCl2 interfering species in the retrieval o better representation of the measurements, proven by the fact that a smaller chi-square is obtained for most of the species; o better handling of diurnally varying interfering species, coming from the use of diurnally varying Initial Guess profiles; o products of five new species (HCFC-22, CFC-14, COF2, CCl4 and HCN) available. Concerning V7 products, preliminary verifications have been performed only on the diagnostic dataset V7, including more than 4000 orbits: the Non-Linearity correction performed in the L1 files introduces a drift in V7 profiles with respect to previous versions, that corrects for the instrumental drift present in previous datasets. Some problems have also been identified: V7 FR Temperature profiles in polar and midlatitude regions presents a negative bias of about 0.5-1K with respect to both V6 products and correlative measurements coming from the Non-Linearity correction. In the tropics in general V7 Temperature has a positive bias with respect to previous versions, for both FR and OR measurements, and this seems to come from the new approach for handling continuum. A new version of the spectroscopic database has been finalized, with improvements in H2O, HNO3, COCl2 and C3H8. The new version of the spectroscopic database will be used for the final reprocessing of the whole MIPAS mission in the frame of the subsequent contract. A large effort was spent for improving the quality of the MIPAS L2 products, but further improvements have been identified as needed to reduce some systematic errors of the products and to fully exploit the information contained in MIPAS measurements. One of the main problems identified so far is the error due to the horizontal inhomogeneities that are not currently taken into account by the algorithm. The quality of the retrieval is affected by the horizontal gradients but from the analysis of single scans no enough information is contained in the measurements to retrieve the gradients. Considering that the code will be used only for a reanalysis, the choice has been to take advantage of the information on horizontal gradients of both temperature and target species from previous reprocessing or ECMWF reanalysis and to modify the forward model in order to handle the externally provided gradients. Another important objective is the full exploitation of MIPAS measurements that implies the retrieval of weaker and weaker species, whose interference from other species cannot be disentangled. To this purpose the possibility of performing a multi-target retrieval is crucial. Furthermore, we have to consider that the vertical profile retrieval of weak species requires the use of some constraint for the attainment of a fast and useful product and it can be useful to have the possibility of tuning or removing it as needed during the average procedure. To this purpose Optimal Estimation seems to be more apt than the current approach where the constraint is determined with a self-consistent method, difficult to rebuild. For very weak species a posteriori averages of retrieved profiles after removing a priori constrain, as studied in the frame of this project, can be also considered. Validation of ML2PP V7 and further investigations aimed to solve these open issues will be completed in the frame of the subsequent contract.