This paper studies parsimonious, intuitive, and effective formulas to approximate the length of Traveling Salesman Problems (TSP) and Vehicle Routing Problems (VRP). Using intuition derived from continuous models and graph theory, a formula to approximate the length of vehicle routes is proposed. In instances with different patterns of customer spatial distribution, time windows, customer deman...

This paper addresses the capacitated vehicle routing problem with twodimensional loading constraints (2L-CVRP). The 2L-CVRP is a combination of the two most important problems in distribution logistics, which are loading of freight into vehicles, and the successive routing of the vehicles to satisfy customer demand. The objective is to minimize the transportation cost. All vehicles must start a...

In one-to-one Pickup and Delivery Problems (PDPs), the aim is to design a set of least cost vehicle routes starting and ending at a common depot in order to satisfy a set of pickup and delivery requests between location pairs, subject to side constraints. Each request originates at one location and is destined for one other location. These requests apply to the transportation of goods or people...

This article presents a mathematical model of the risk failures, depending on operating parameters, locomotive diesel engines. The purpose this study is to determine failures engines in maintenance. theory probability and logic reliability are used theoretical study. innovations main works first approaches calculating by hourly fuel consumption, which, under operational conditions, allows for e...

The article addresses the well-known Capacitated Vehicle Routing Problem (CVRP), in the special case where the demand of a customer consists of a certain number of two-dimensional weighted items. The problem calls for the minimization of the cost of transportation needed for the delivery of the goods demanded by the customers, and carried out by a fleet of vehicles based at a central depot. In ...

In this paper, we address the Two-Echelon Vehicle Routing Problem (2E-VRP) in which freight is delivered from depots to intermediary satellites, from where it is delivered to customers. Different from other multi-level problems, the focus in 2E-VRP is on the global routing costs of the overall network. 2E-VRP has been recently introduced and, to our knowledge, there are no studies of the impact...

occurrence of natural disaster inflicts irreparable injuries and symptoms on humans. in such conditions, affected people are waiting for medical services and relief commodities. thus, quick reaction of medical services and relief commodities supply play important roles in improving natural disaster management. in this paper, a multi-objective non-linear credibility-based fuzzy mathematical prog...

In this year-long, prospective observational study, sociodemographic, clinical, and functional characteristics were assessed in outpatients with schizophrenia from Australia, Mexico, Romania, and Taiwan who were switched from their primary oral antipsychotic to another oral or depot antipsychotic at study entry because of physician-perceived nonadherence risks. Patients (N = 406) rated their qu...

of prior cloud work: The PIs have built Depot, a cloud storage system that minimizes trust assumptions. Depot tolerates buggy or malicious behavior by any number of clients or servers, yet it provides safety and liveness guarantees to correct clients. Depot provides these guarantees using a two-layer architecture. First, Depot ensures that the updates observed by correct nodes are consistently ...