85 research outputs found

    A multiperiod drayage problem with customer-dependent service periods

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    We investigate a routing problem arising in the domain of drayage operations. to determine mimimum-cost vehicle routes in several periods. We adapt a set-covering model, which is solved either with all feasible routes by an off-the-shelf MIP solver, or by and a Price-and-Branch algorithm in which the pricing problem is a formulated as a collection of shortest path problems in tailor-made auxiliary acyclic networks. We propose a new arc-flow formulation based on the previous auxiliary networks and show that solving it by a MIP solver is usually preferable. Finally, we characterize how possible changes in flexibility levels affect routing costs

    Impatto ambientale dell'attivitĂ  mineraria in Sardegna: studi mineralogici e geochimici

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    Sardinia is characterized by a large variety of geologic and hydrologic environments, and by a rich wealth of mineral resources, that fueled a millennial history of mining activity. Therefore, it provides an excellent ground for studies of the environmental impact of mining activity. In this communication, we summarize the results of our studies, specifically concerning the deposits of Baccu Locci (polymetallic�Pb,As), Furtei (epithermal Au), Monteponi (Pb-Zn-Ag), and Montevecchio (Pb-Zn-Ag). In abandoned mining districts (Baccu Locci, Monteponi, and Montevecchio), because of a poor management of environmental issues, we observe significant heavy metal contamination. On the other hand, in the active Furtei mine the first four years of exploitation did not cause remarkable changes with respect to pre-mining baseline conditions

    An adaptive guidance meta-heuristic for the vehicle routing problem with splits and clustered backhauls

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    This paper presents the case study of an Italian carrier, Grendi Trasporti Marittimi, which provides freight transportation services by trucks and containers. Its trucks deliver container loads from a port to import customers and collect container loads from export customers to the same port. In this case study, all import customers in a route must be serviced before all export customers, each customer can be visited more than once and containers are never unloaded or reloaded from the truck chassis along any route. We model the problem using an Integer Linear Programming formulation and propose an Adaptive Guidance metaheuristic. Our extensive computational experiments show that the adaptive guidance algorithm is capable of determining good-quality solutions in many instances of practical or potential interest for the carrier within 10 min of computing time, whereas the mathematical formulation often fails to provide the first feasible solution within 3 h of computing time

    Lurasidone in adolescents and adults with schizophrenia: from clinical trials to real-world clinical practice

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    Introduction: Lurasidone is an atypical antipsychotic agent approved in the European Union for the treatment of schizophrenia in adults and adolescents (13-17 years). Clinical trials have shown a generally favorable balance between efficacy and tolerability. Areas covered: This paper provides a review and commentary regarding the use of lurasidone in adults and adolescents with schizophrenia. The available information about efficacy, tolerability, dosing, and switching is analyzed, highlighting the strategies that may be most useful in real-world clinical practice. Virtual case studies, designed based on the authors' clinical experience with real-world patients, are provided. Expert opinion: Lurasidone is efficacious in adolescents and adults in a wide range of symptoms of schizophrenia. Choosing the right dose for each patient and combining lurasidone with other medications is key to treatment success. Lurasidone has proven effective both in adolescents and adults in treating the acute phase of schizophrenia and reducing the risk of relapse. It has shown a relatively favorable tolerability profile, with minimal effects on metabolic parameters and prolactin levels

    La numerazione binaria: PITTONUMERI

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    This work displays a new start for the representation of natural number
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