A Finite-Time Cutting Plane Algorithm for Distributed Mixed Integer Linear Programming

Many problems of interest for cyber-physical network systems can be formulated as Mixed Integer Linear Programs in which the constraints are distributed among the agents. In this paper we propose a distributed algorithm to solve this class of optimization problems in a peer-to-peer network with no coordinator and with limited computation and communication capabilities. In the proposed algorithm, at each communication round, agents solve locally a small LP, generate suitable cutting planes, namely intersection cuts and cost-based cuts, and communicate a fixed number of active constraints, i.e., a candidate optimal basis. We prove that, if the cost is integer, the algorithm converges to the lexicographically minimal optimal solution in a finite number of communication rounds. Finally, through numerical computations, we analyze the algorithm convergence as a function of the network size.Comment: 6 pages, 3 figure

«WALLSCAPES»: EVOLUTION OF THE MARANO HILL FORTIFICATIONS (CUPRA MARITTIMA - ITALY) THROUGH MATERIALITY AND PERCEPTIONS

The article analyses the walls of Marano, a small town in the back-coastal hills of the Marche region, between Fermo and Ascoli. Written sources related to the development of the settlement and data derived from the walls that still stand have been analysed. Moreover, a short insight into the development of the settlement in relation to the walls is presented through the results acquired during the archaeological excavation undertaken in 2018. Finally, the article explains how the perception of the walls has changed over time in relation to the Marano geopolitical context and the rediscovery of the Roman period settlement

Da Cupra a Marano. Insediamenti e abitati, traslazioni e transizioni

L’intervento intende illustrare i risultati della prima campagna di ricerche svolte dall’Università Ca’ Foscari Venezia nel territorio di Cupra Marittima (AP). Le ricerche sono state condotte lungo la valle del torrente Menocchia, appena a N dell’attuale centro costiero, e nel borgo di Marano, posto sui primi rilievi collinari. Il progetto si pone l’obiettivo generale di studiare la parabola dell’insediamento cuprense tra la tarda antichità e il medioevo. La valle del torrente Menocchia è stata oggetto di sondaggi geoarcheologici realizzati tramite trivella manuale. Sono stati indagati i primi cinque metri di stratificazione su un’area di circa 25 ettari. Gli interventi sono stati finalizzati alla prima esplorazione della zona in cui si colloca tradizionalmente il porto romano e, più generalmente, alla definizione, seppure parziale, delle trasformazioni geomorfologiche che hanno coinvolto il centro originario di Cupra a partire dalla tarda antichità. Nel borgo di Marano, invece, è stata effettuata una prima valutazione del potenziale informativo degli edifici ancora in elevato e sono stati realizzati il rilievo e la lettura stratigrafica dei prospetti dell’edificio che attualmente ospita il Museo Archeologico Comunale del territorio di Cupra Marittima, appartenente al primo nucleo medievale dell’abitato. Questa prima fase di ricerche ha permesso di gettare le basi per lo studio delle tecniche costruttive e lo sviluppo urbano del borgo

Optimal rendezvous trajectory for unmanned aerial-ground vehicles

Fixed-wing unmanned aerial vehicles (UAVs) can be an essential tool for low cost aerial surveillance and mapping applications in remote regions. There is however a key limitation, which is the fact that low cost UAVs have limited fuel capacity and hence require periodic refueling to accomplish a mission. Moreover, the usual mechanism of commanding the UAV to return to a stationary base station for refueling can result in fuel wastage and inefficient mission operation time. Alternatively, one strategy could be the use of an unmanned ground vehicle (UGV) as a mobile refueling unit, where the UAV will rendezvous with the UGV for refueling. In order to accurately perform this task in the presence of wind disturbances, we need to determine an optimal trajectory in 3D taking UAV and UGV dynamics and kinematics into account. In this paper, we propose an optimal control formulation to generate a tunable UAV trajectory for rendezvous on a moving UGV that also addresses the possibility of the presence of wind disturbances. By a suitable choice of the value of an aggressiveness index that we introduce in our problem setting, we are able to control the UAV rendezvous behavior. Several numerical results are presented to illustrate the reliability and effectiveness of our approach

Brain Networks and Cognitive Impairment in Parkinson's Disease

: Aim: The aim of the present study is to investigate the relationship between both functional connectivity and brain networks with cognitive decline, in patients with Parkinson's disease (PD). Introduction: PD phenotype is not limited to motor impairment but, rather, a wide range of non-motor disturbances can occur, with cognitive impairment being one of the most common. However, how the large-scale organization of brain activity differs in cognitively impaired patients, as opposed to cognitively preserved ones, remains poorly understood. Methods: Starting from source-reconstructed resting-state magnetoencephalography data, we applied the phase linearity measurement (PLM) to estimate functional connectivity, globally and between brain areas, in PD patients with and without cognitive impairment (respectively PD-CI and PD-NC), as compared with healthy subjects (HS). Further, using graph analysis, we characterized the alterations in brain network topology and related these, as well as the functional connectivity, to cognitive performance. Results: We found reduced global and nodal PLM in several temporal (fusiform gyrus, Heschl's gyrus, and inferior temporal gyrus), parietal (postcentral gyrus), and occipital (lingual gyrus) areas within the left hemisphere, in the gamma band, in PD-CI patients, as compared with PD-NC and HS. With regard to the global topological features, PD-CI patients, as compared with HS and PD-NC patients, showed differences in multi-frequencies bands (delta, alpha, gamma) in the Leaf fraction, Tree hierarchy (Th) (both higher in PD-CI), and Diameter (lower in PD-CI). Finally, we found statistically significant correlations between the Montreal Cognitive Assessment test and both the Diameter in delta band and the Th in the alpha band. Conclusion: Our work points to specific large-scale rearrangements that occur selectively in cognitively compromised PD patients and are correlated to cognitive impairment. Impact statement In this article, we want to test the hypothesis that the cognitive decline observed in Parkinson's disease (PD) patients may be related to specific changes of both functional connectivity and brain network topology. Specifically, starting from magnetoencephalography signals and by applying the phase linearity measurement (PLM), a connectivity metric that measures the synchronization between brain regions, we were able to highlight differences in the global and nodal PLM values in PD patients with cognitive impairment as compared with both cognitively unimpaired patients and healthy subjects. Further, using graph analysis, we analyzed alterations in brain network topology that were related to cognitive functioning

Optimal Rendezvous Trajectory for Unmanned Aerial-Ground Vehicles

(c) 2017 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.Fixed-wing unmanned aerial vehicles (UAVs) can be an essential tool for low cost aerial surveillance and mapping applications in remote regions. There is however a key limitation, which is the fact that low cost UAVs have limited fuel capacity and hence require periodic refueling to accomplish a mission. Moreover, the usual mechanism of commanding the UAV to return to a stationary base station for refueling can result in fuel wastage and inefficient mission operation time. Alternatively, one strategy could be the use of an unmanned ground vehicle (UGV) as a mobile refueling unit, where the UAV will rendezvous with the UGV for refueling. In order to accurately perform this task in the presence of wind disturbances, we need to determine an optimal trajectory in 3D taking UAV and UGV dynamics and kinematics into account. In this paper, we propose an optimal control formulation to generate a tunable UAV trajectory for rendezvous on a moving UGV that also addresses the possibility of the presence of wind disturbances. By a suitable choice of the value of an aggressiveness index that we introduce in our problem setting, we are able to control the UAV rendezvous behavior. Several numerical results are presented to illustrate the reliability and effectiveness of our approach

Amnestic Mild Cognitive Impairment Is Associated With Frequency-Specific Brain Network Alterations in Temporal Poles

There is general agreement that the neuropathological processes leading to Alzheimer’s disease (AD) begin decades before the clinical onset. In order to detect early topological changes, we applied functional connectivity and network analysis to magnetoencephalographic (MEG) data obtained from 16 patients with amnestic Mild Cognitive Impairment (aMCI), a prodromal stage of AD, and 16 matched healthy control (HCs). Significant differences between the two groups were found in the theta band, which is associated with memory processes, in both temporal poles (TPs). In aMCI, the degree and betweenness centrality (BC) were lower in the left superior TP, whereas in the right middle TP the BC was higher. A statistically significant negative linear correlation was found between the BC of the left superior TP and a delayed recall score, a sensitive marker of the “hippocampal memory” deficit in early AD. Our results suggest that the TPs, which are involved early in AD pathology and belong to the memory circuitry, have an altered role in the functional network in aMCI

From documents to the ground. The early medieval landscape of Comacchio

Starting from the results of the archaeological excavations lead by the Ca' Foscari University of Venice between 2006 and 2010, this paper offers a reconstruction of the landscape of Comacchio in the Early Middle Ages (VII-X Century). The emporium of Comacchio was founded in a lagoon area not far from important tributaries of the Po river. The research was based on traditional topographic methods (study of historical cartography and place names, analysis of aerial photography); it also turned to geoarcheology in order to investigate the site of St. Maria in Padovetere.Starting from the results of the archaeological excavations lead by Università Ca' Foscari di Venezia between 2006 and 2010, this paper offers a reconstruction of the landscape of Comacchio in the Early Middle Ages (VIIth-Xth century). The emporium of Comacchio was founded in a lagoon area not far from important tributaries of the Po river. The research was based on traditional topographic methods (study of historical cartography and place names, analysis of aerial photography); it also turned to geoarchaeology in order to investigate the site of St. Maria in Padovetere