The Vehicle Routing Problem with TimeWindows (VRPTW) consists in determining the routing plan of vehicles with identical capacity in order to supply the demands of a set of customers with predefined time windows. This complex multi-constrained problem has been widely studied due to its industrial, economic and environmental implications. In this work, we are interested in defining the number of...

The United States Coast Guard (USCG), a part of the U.S. Department of Homeland Security, is the nation’s leading agency in maritime security, safety, and stewardship. One of the primary USCG resources is a fleet of boats (maritime vessels less than 65 feet in length) of various types that must be allocated to USCG stations nationwide. This paper describes the academic-industry collaboration be...

This study compares the fishing activity and landings of the trawl and creel fisheries for Norway lobster (Nephrops norvegicus (L.)) off the Portuguese coast, and evaluates the financial viability of two vessels typical of each fleet. Crustacean trawlers are part of an industrial fleet that, besides Nephrops, targets deep water shrimps. Creels are used by a multi-gear, multi-target artisanal fl...

We introduce a simple yet efficient approach to optimize the modal fleet size of urban public transportation services, considering both user- and operator-oriented factors. This is envisaged enhance potential for achieving sustainable systems and, eventually, opportunities create cities. The presented constraint optimization can be described as follows. First, expected passenger demand cycle ti...

In order to anticipate failures and reduce downtime, “predictive diagnostic” aims not only at warning about the failure events before they occur but also at identifying the causes of degradation leading to such detections. Then, based on the results of predictive diagnostic, “prognostic” aims at estimating the remaining useful life in order to plan a maintenance action before unit performances ...

Fleet management addresses the problem of managing fleets of trailers, containers, boxcars, taxicabs, locomotives and business jets. In many applications, requests to be moved from one location to another arrive randomly over time. Since it may take days to move from one location to the next, it is often useful (even necessary) to reposition equipment before a customer demand is known. We use t...

Fleet automation often involves solving several strongly correlated sub-problems, including task allocation, motion planning, and coordination. Solutions need to account for very specific, domaindependent constraints. In addition, several aspects of the overall fleet management problem become known only online. We propose a method for solving the fleet-management problem grounded on a heuristic...

The Sierra report proposes a methodology for states to use to demonstrate that their Inspection and Maintenance (I/M) programs are obtaining emissions reductions similar to those estimated by the MOBILE emissions factor model. The proposed methodology involves comparing fleetwide test average emissions of a state I/M program with those of a benchmark program (Sierra suggests using the Arizona I...