326,213 research outputs found
An extension of Hu's group minimization algorithm
No full textIn this work the Author extends Hu's algorithm to solve pure integer linear programming problems.
The extension is applied when the solution of the «relaxed asymptotic» problem is unfeasible for the original program. This extension provides a mean of solution in a good number of cases, when the application of the classical asymptotic algorithm fails.
Numerical examples are presented.
A criterion, which guarantees when the algorithm works, is also given.
In questo lavoro si estende l'algoritmo di Hu per risolvere problemi di programmazione lineare totalmente a variabili itere.
L'estensione si applica nei casi in cui la soluzione del problema «asintotico rilassato» fornisce una soluzione inaccettabile per il problema originario.
In questo modo, un buon numero di casi, in cui l'algoritmo asintotico non giunge alla soluzione ottima, possono essere risolti. Viene anche indicato un criterio che assicura l'uso dell'algoritmo qui proposto
A New Algorithm for Box-Constrained Global Optimization
No full textAn important class of deterministic methods for global optimization is based on the theory of terminal attractors and repellers. Unfortunately, the utilization of scalar repellers is unsuitable, when the dimension n of the problem assumes values of operational interest. In previous papers the author et al. showed that BFSG-type methods, approximating the Hessian of twice continuously differentiable functions with a structured matrix, are very efficient to compute local minima, particularly in the secant case. On the other hand, the algorithms founded on the classical αBB technique are often ineffective for computational reasons. In order to increase the power of repellers in the tunneling phases, the utilization of repeller matrices with a proper structure is certainly promising and deserves investigation. In this work, it is shown that a BFGS-type method of low complexity, implemented in the local optimizations, can be effectively matched with proper repeller matrices in the tunneling phases. The novel algorithm FBαBB, which can be applied in the frame of the αBB computational scheme, is very efficient in terms of Number of Functions Generations (NFG), Success Rates (SR) in the evaluation of the global minimum and Number of Local Searches (NLS)
Developments in managing severe chronic pain: role of oxycodone–naloxone extended release
No full textGuido Fanelli,1 Andrea Fanelli2 1Anesthesia and Intensive Care Unit, University of Parma, Parma, 2Anesthesia and Intensive Care Unit, Policlinico S Orsola-Malpighi, Bologna, Italy Abstract: Chronic pain is a highly disabling condition, which can significantly reduce patients’ quality of life. Prevalence of moderate and severe chronic pain is high in the general population, and it increases significantly in patients with advanced cancer and older than 65 years. Guidelines for the management of chronic pain recommend opioids for the treatment of moderate-to-severe pain in patients whose pain is not responsive to initial therapies with paracetamol and/or nonsteroidal anti-inflammatory drugs. Despite their analgesic efficacy being well recognized, adverse events can affect daily functioning and patient quality of life. Opioid-induced constipation (OIC) occurs in 40% of opioid-treated patients. Laxatives are the most common drugs used to prevent and treat OIC. Laxatives do not address the underlying mechanisms of OIC; for this reason, they are not really effective in OIC treatment. Naloxone is an opioid receptor antagonist with low systemic bioavailability. When administered orally, naloxone antagonizes the opioid receptors in the gut wall, while its extensive first-pass hepatic metabolism ensures the lack of antagonist influence on the central-mediated analgesic effect of the opioids. A prolonged-release formulation consisting of oxycodone and naloxone in a 2:1 ratio was developed trying to reduce the incidence of OIC maintaining the analgesic effect compared with use of the sole oxycodone. This review includes evidence related to use of oxycodone and naloxone in the long-term management of chronic non-cancer pain and OIC. Keywords: chronic pain, opioid-induced constipation, opioids, oxycodone–naloxon
On the connectivity of maximal planar graphs with minimum degree 5
No full textLet F_(n,k) be the classes of maximal planar graphs G_n (without loops or multiple edges) having k vertices of degree 5 and n-k vertices of degree more than 5. Hakimi and Schmeichel proved that, if G_n belongs to F_(n,k) and k=12,13, then G_n is 5-connected. In this paper the author gives some general conditions in terms of the integers n and k for a graph G_n to be p-connected, with p=4,
Un ditirambo barese di Sigismondo Fanelli
No full textAnalisi del ditirambo In laudem viri clari et praeclari di S. Fanelli
Sull'uso dell'algoritmo asintotico in problemi applicativi di programmazione lineare a variabile intere
No full textOn the existence and connectivity of a class of maximal planar graphs
No full textIn this work the author determines completely which Euler maximal graphs having 14 vertices of degree 5 and n-14 vertices of degree more than 5 are planar. Furthermore, a sufficient condition for such graphs to be 5-connected is also given
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