52 research outputs found
Energy-Constrained Delivery of Goods with Drones Under Varying Wind Conditions
In this paper, we study the feasibility of sending drones to deliver goods
from a depot to a customer by solving what we call the Mission-Feasibility
Problem (MFP). Due to payload constraints, the drone can serve only one
customer at a time. To this end, we propose a novel framework based on
time-dependent cost graphs to properly model the MFP and tackle the delivery
dynamics. When the drone moves in the delivery area, the global wind may change
thereby affecting the drone's energy consumption, which in turn can increase or
decrease. This issue is addressed by designing three algorithms, namely: (i)
compute the route of minimum energy once, at the beginning of the mission, (ii)
dynamically reconsider the most convenient trip towards the destination, and
(iii) dynamically select only the best local choice. We evaluate the
performance of our algorithms on both synthetic and real-world data. The
changes in the drone's energy consumption are reflected by changes in the cost
of the edges of the graphs. The algorithms receive the new costs every time the
drone flies over a new vertex, and they have no full knowledge in advance of
the weights. We compare them in terms of the percentage of missions that are
completed with success (the drone delivers the goods and comes back to the
depot), with delivered (the drone delivers the goods but cannot come back to
the depot), and with failure (the drone neither delivers the goods nor comes
back to the depot).Comment: typo author's nam
Optimal Routing Schedules for Robots Operating in Aisle-Structures
In this paper, we consider the Constant-cost Orienteering Problem (COP) where
a robot, constrained by a limited travel budget, aims at selecting a path with
the largest reward in an aisle-graph. The aisle-graph consists of a set of
loosely connected rows where the robot can change lane only at either end, but
not in the middle. Even when considering this special type of graphs, the
orienteering problem is known to be NP-hard. We optimally solve in polynomial
time two special cases, COP-FR where the robot can only traverse full rows, and
COP-SC where the robot can access the rows only from one side. To solve the
general COP, we then apply our special case algorithms as well as a new
heuristic that suitably combines them. Despite its light computational
complexity and being confined into a very limited class of paths, the optimal
solutions for COP-FR turn out to be competitive even for COP in both real and
synthetic scenarios. Furthermore, our new heuristic for the general case
outperforms state-of-art algorithms, especially for input with highly
unbalanced rewards
Dispatching Point Selection For A Drone-based Delivery System Operating In A Mixed Euclidean–Manhattan Grid
In this paper, we present a drone-based delivery system that assumes to deal with a mixed-area, i.e., two areas, one rural and one urban, placed side-by-side. In the mixed-areas, called EM-grids, the distances are measured with two different metrics, and the shortest path between two destinations concatenates the Euclidean and Manhattan metrics. Due to payload constraints, the drone serves a single customer at a time returning back to the dispatching point (DP) after each delivery to load a new parcel for the next customer. In this paper, we present the 1 -Median Euclidean–Manhattan grid Problem (MEMP) for EM-grids, whose goal is to determine the drone\u27s DP position that minimizes the sum of the distances between all the locations to be served and the point itself. We study the MEMP on two different scenarios, i.e., one in which all the customers in the area need to be served (full-grid) and another one where only a subset of these must be served (partial-grid). For the full-grid scenario we devise optimal and approximation algorithms, while for the partial-grid scenario we devise an optimal algorithm
Low incidence of Permanent Complications During Catheter Ablation for Atrial Fibrillation using open irrigated catheters: a multicenter registry
Subcontracting in Italian Industry: Labour Division, Firm Growth and the North–South Divide
Apertura internazionale e risorse locali. Un'indagine sul radicamento territoriale di imprese multinazionali
Questo articolo analizza le relazioni fra strategie di sviluppo internazionale delle imprese
manifatturiere e il sistema delle risorse economiche locali, costituite da capitale umano,
reti di fornitori e utilizzatori, nonché istituzioni. Lo studio cerca di verificare se e in quale
misura le imprese più aperte alle reti internazionali hanno sostenuto la riproduzione del capitale
territoriale nella propria base domestica. La ricerca, condotta attraverso un insieme di casi studio
di aziende manifatturiere venete di medio-grande dimensione, mette in luce l’insieme di possibili
azioni praticate dalle imprese per favorire la sostenibilità delle risorse territoriali
Do Emerging Country MNEs Sustain Advanced Country’s Industrial Commons? Evidence from Italian productive local systems
Apertura internazionale e risorse economiche locali. Un’indagine sul radicamento territoriale di imprese multinazionali
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