85 research outputs found
A Differential Evolution algorithm to deal with box, linear and quadratic-convex constraints for boundary optimization
No full textConstrained global optimization, Boundary optimization, Differential evolution, Generalized differential evolution,
Computing the variance of interval and fuzzy data
No full textWe propose an algorithm for the computation of the interval and fuzzy variance. In particular, based on the application of the max–min inequality, we obtain an upper bound to the maximization problem and we indicate how to obtain a feasible (heuristic) solution from the upper bound. The procedure requires the minimization of a unidimensional (continuous) convex function over a compact interval, for which efficient procedures exist. Having determined the upper bound, we are able to estimate the quality of any heuristic solution. Some computational results for problems of different dimensions are reported
Handling Box, Linear and Quadratic-Convex Constraints for Boundary Optimization with Differential Evolution Algorithms
No full textWe propose and test the performance of an implicit strategy to handle box, linear and quadratic convex constraints, based on changing the search space from points to directions, suitable to be easily implemented in combination with differential evolution (DE) algorithms for the boundary optimization of a generic continuous function. In particular, we see that DE can be efficiently implemented to find solutions on the boundary of box constraints, linear inequality constraints and quadratic convex constraints, for which the feasible set is convex and bounded. The computational results are performed on different classes of minimization problems
Web-GIS per l’interrogazione guidata di dati geologico-tecnici per la microzonazione sismica
No full text
Partitioning a matrix to minimize the maximum cost
No full textAbstractA matrix A = [aij] of nonnegative integers must be partitioned into p blocks (submatrices) corresponding to a set of vertical cuts parallel to the columns and a set of horizontal cuts parallel to the rows. With each block is associated a cost equal to the sum of its elements. We consider the problem of finding a matrix partitioning that minimizes the cost of the block of maximum cost.In this paper a mathematical formulation of the problem is given and used to derive both exact and heuristic algorithms.Lower bounds and dominance criteria are exploited in a tree search algorithm for finding the optimal solution of the problem. Computational results of the proposed algorithm are given on a number of randomly generated test problems
THE EFFECT OF ORGANIC COSOLVENTS ON THE ENANTIOSELECTIVITY IN THE BOVINE SERUM-ALBUMIN CATALYZED WEITZ-SCHEFFER CONDENSATION
No full textWater miscible or immiscible organic cosolvents can strongly influence the enantioselectivity of the Weitz-Scheffer condensation catalyzed by bovine serum albumin, the enantiomeric excess (e.e.) being in the range 0-90%
Un tredicenne con “asma grave” e una curva flusso-volume caratteristica
No full textL’arco aortico destroposto rappresenta una anomalia congenita rara dell’aorta che, nel 50% dei
casi, si associa alla presenza di un’arteria succlavia sinistra aberrante che origina da un aneurisma dell’aorta
discendente, noto come diverticolo di Kommerell (KD), dando vita a un anello vascolare incompleto che può provocare
una compressione della trachea e dell’esofago, con conseguente comparsa di tosse, dispnea e/o disfagia.
Ancor più raramente il KD non si associa all’arteria succlavia aberrante e può costituire un rilievo casuale nel corso
di accertamenti eseguiti per altri motivi. Tuttavia, la presenza di un KD è una condizione da non sottovalutare
a causa dell’alta mortalità legata alla sua dissezione o rottura in età adulta.
Descriviamo il caso di un tredicenne con arco aortico destroposto e KD isolato, con morfologia della curva flusso-
volume patognomonica, trattato per molti anni per asma grave
Ship control system wide integration and the use of dynamic simulation techniques in the Fremm project
No full textOxidative stress plays an important role in the “mal secco” disease caused by Phoma tracheiphila.
No full text- …
