A reclaimer scheduling problem arising in coal stockyard management

We study a number of variants of an abstract scheduling problem inspired by the scheduling of reclaimers in the stockyard of a coal export terminal. We analyze the complexity of each of the variants, providing complexity proofs for some and polynomial algorithms for others. For one, especially interesting variant, we also develop a constant factor approximation algorithm.Comment: 26 page

A simulation framework for the design of a station-based bike sharing system

Many cities and towns offer nowadays to citizens a bike sharing system (BSS). When a company starts the service, several decisions have to be taken on the location and size of the rental stations, and the number of vehicles to use to re-balance the bikes in the stations, in addition to the cost and policies for the payment of the service. Also, when the service is in place, it is often necessary to modify it, in many cases to expand it. In this paper, starting from the experience gained in a real-case application, we present a simulation framework to support the tactical decisions in the design or revision of a BSS. We will also present the application of the framework to the case of Bicimia in Brescia, Italy

Sleepiness, Neuropsychological Skills, and Scholastic Learning in Children

Abstract: Excessive daytime sleepiness is a frequent condition among children and adolescents that may lead to several and significant daytime consequences, including impaired neurocognitive skills and scholastic performance. Here, we evaluated in one hundred and ninety-one unselected primary school children, the relationship between sleepiness and a wide range of cognitive and academic skills through a standardized neuropsychological test battery. In order to assess the statistical relationship, we performed a partial least squares path modelling, a non-parametrical approach which combined a model of paths between latent variables and the coefficients between indicators and dimensions. Results were validated through the bootstrap approach and suggest that sleepiness is not associated with all cognitive and scholastic abilities, but only with those relying on verbal abilities and complex cognitive functions (i.e., reading comprehension, oral/syntactic comprehension, spelling, and mathematic skills). Our data suggest the idea that sleepiness in children is associated mostly with “higher” (mainly verbal) cognitive function(s), while the visuospatial domain was not affected

Complexity and approximation for Traveling Salesman Problems with profits

International audience; In TSP with profits we have to find an optimal tour and a set of customers satisfying a specific constraint. In this paper we analyze three different variants of TSP with profits that are NP-hard in general. We study their computational complexity on special structures of the underlying graph, both in the case with and without service times to the customers. We present polynomial algorithms for the polynomially solvable cases and fully polynomial time approximation schemes (FPTAS) for some NP-hard cases

Polygraphic findings in simplified Barbed Reposition Pharyngoplasty (BRP) as a treatment for OSA patients

This study aims to compare polygraphic data in patients with OSA treated with Barbed Reposition Pharyngoplasty (BRP) performed with a simplified technique compared to the standard method. Variations of technique were performed and tested with the purpose of promoting tolerability and diffusion of this simplified technique. To evaluate the efficacy of the simplified BRP method, a sample of 99 patients was divided into two groups: Group A was treated with BRP (BRP group) and Group B was treated with simplified BRP (sBRP group). The results obtained on the two groups were compared with the two sample Bootstrap t-tests method, showing a substantial overlap in polygraphic results recorded 6 months after surgery

Analisi di algoritmi per problemi di scheduling e routing

Dottorato di ricerca in metodi computazionali per le decisioni economiche e finanziarie. A.a. 199 - 9. Tutore Maria Grazia SperanzaConsiglio Nazionale delle Ricerche - Biblioteca Centrale - P.le Aldo Moro, 7 Rome; Biblioteca Nazionale Centrale - P.za Cavalleggeri, 1, Florence / CNR - Consiglio Nazionale delle RichercheSIGLEITItal

American and European Portfolio Selection Strategies: The Markovian Approach

Technical Report n. 309, Department of Quantitative Methods, University of Bresci