Search results for " Vehicle"
showing 10 items of 389 documents
S2k guidelines for the use of topical preparations on the skin
2018
The present guidelines are aimed at dermatology residents and board-certified dermatologists as well as policymakers and insurance companies. Developed by dermatologists in collaboration with pharmacists using a formal consensus process (S2k), they include general aspects with respect to pharmacokinetics and regulatory terminology. Recommendations are provided on the various indications for extemporaneous preparations and their quality assurance. The importance of pharmaceutical vehicles and problems associated with substituting one vehicle for another are discussed. The guidelines include criteria for choosing a suitable pharmaceutical vehicle and for specific aspects in terms of treatment…
Contributions to Branch-and-Price-and-Cut Algorithms for Routing Problems
2019
This article deals with new exact branch-and-price-and-cut algorithms for the solution of routing problems. Specialized methods for the pickup-and-delivery problem (PDP), the truck-and-trailer routing problem (TTRP), the periodic vehicle routing problem (PVRP) and a service network design and hub location problem (SNDHLP) are presented. We develop a new technique for the acceleration of bidirectional labeling algorithms by a dynamic choice of the merge point. Moreover, for variants of the PDP, the bidirectional labeling can be effectively applied for the first time. In the TTRP, we model the extension to a 2 days planning horizon and the consideration of a quantity-dependent transfer time. …
Traffic Flow Variables Estimation: An Automated Procedure Based on Moving Observer Method. Potential Application for Autonomous Vehicles
2019
Abstract The estimation of traffic flow variables (flow, space mean speed and density) plays a fundamental role in highways planning and designing, as well as in traffic control strategies. Moving Observer Method (MOM) allows traffic surveys in a road, or in a road network. This paper proposes a novel automated procedure, called MOM-AP based on Moving Observer Method and Digital Image Processing (DIP) Technique able to automatically detect (without human observers) and calculate flow q, space mean speed vs and density k in case of stationary and homogeneous traffic conditions. In order to evaluate how reliable is the MOM-AP, an experiment has been carried out in a segment of one two-lane si…
Fatigue Monitoring Tool for Airline Operators (FMT)
2017
Abstract A Fatigue Monitoring Tool (FMT) model was constructed for an operational airline in order to manage the fatigue levels of their crews in accordance with Fatigue Risk Management System (FRMS) practices. This article describes the implementation of the Fatigue Monitoring Tool model and the airline’s aims to put the recent scientific findings on aviation fatigue into practical use. The model consists of proxy points allotted to various duties and rest periods.
A more efficient cutting planes approach for the green vehicle routing problem with capacitated alternative fuel stations
2021
AbstractThe Green Vehicle Routing Problem with Capacitated Alternative Fuel Stations assumes that, at each station, the number of vehicles simultaneously refueling cannot exceed the number of available pumps. The state-of-the-art solution method, based on the generation of all feasible non-dominated paths, performs well only with up to 2 pumps. In fact, it needs cloning the paths between every pair of pumps. To overcome this issue, in this paper, we propose new path-based MILP models without cloning paths, for both the scenario with private stations (i.e., owned by the fleet manager) and that with public stations. Then, a more efficient cutting plane approach is designed for addressing both…
Branch-and-Cut for the Split Delivery Vehicle Routing Problem with Time Windows
2019
The split delivery vehicle routing problem with time windows (SDVRPTW) is a notoriously hard combinatorial optimization problem. First, it is hard to find a useful compact mixed-integer programming (MIP) formulation for the SDVRPTW. Standard modeling approaches either suffer from inherent symmetries (mixed-integer programs with a vehicle index) or cannot exactly capture all aspects of feasibility. Because of the possibility to visit customers more than once, the standard mechanisms to propagate load and time along the routes fail. Second, the lack of useful formulations has rendered any direct MIP-based approach impossible. Up to now, the most effective exact algorithms for the SDVRPTW hav…
Stabilized branch-price-and-cut for the commodity-constrained split delivery vehicle routing problem
2019
Abstract In the commodity-constrained split delivery vehicle routing problem (C-SDVRP), customer demands are composed of sets of different commodities. The C-SDVRP asks for a minimum-distance set of routes such that all customer demands are met and vehicle capacities are respected. Moreover, whenever a commodity is delivered by a vehicle to a customer, the entire amount requested by this customer must be provided. Different commodities demanded by one customer, however, can be delivered by different vehicles. Thus, the C-SDVRP is a relaxation of the capacitated vehicle routing problem and a restriction of the split delivery vehicle routing problem. For its exact solution, we propose a branc…
The Split Delivery Vehicle Routing Problem with Time Windows and Customer Inconvenience Constraints
2019
In classical routing problems, each customer is visited exactly once. By contrast, when allowing split deliveries, customers may be served through multiple visits. This potentially results in substantial savings in travel costs. Even if split deliveries are beneficial to the transport company, several visits may be undesirable on the customer side: At each visit the customer has to interrupt his primary activities and handle the goods receipt. The contribution of the present paper consists in a thorough analysis of the possibilities and limitations of split delivery distribution strategies. To this end, we investigate two different types of measures for limiting customer inconvenience (a m…
Branch-and-Price-and-Cut for the Periodic Vehicle Routing Problem with Flexible Schedule Structures
2019
This paper addresses the periodic vehicle routing problem with time windows (PVRPTW). Therein, customers require one or several visits during a planning horizon of several periods. The possible visiting patterns (schedules) per customer are limited. In the classical PVRPTW, it is common to assume that each customer requires a specific visit frequency and offers all corresponding schedules with regular intervals between the visits. In this paper, we permit all kinds of schedule structures and the choice of the service frequency. We present an exact branch-and-price-and-cut algorithm for the classical PVRPTW and its variant with flexible schedules. The pricing problems are elementary shortes…
From electric mobility to hydrogen mobility: current state and possible future expansions
2020
The expansion of electric vehicles in Italy, has already started a few years ago, but some aspects prevent its expansion. Currently users prefer hybrid technology, mainly due to socio-economic factors related to initial investment and anxiety about autonomy. The aim of the document is to understand if the adoption of Fuel Cell technology can be a solution to overcome the problems of environmental pollution. The possibility to be able to use fuel cells to store electricity is very advantageous, especially on charging times that are significantly reduced. Based on the current situation and analyzing the available data, this work reports the current state of electric mobility in Italy and trie…