Download or read book Median Routing Problems written by and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis studies the shift planning of emergency response organisations and how to include plannable, preventive tasks into the schedules of the responders, such that they remain well spread in case of emergencies. Both halves of this planning have individually received significant attention throughout the past decades: that is, much is known about either positioning responders to minimise emergency response times (e.g. the k-Median Problem) or about efficiently visiting plannable jobs with a fleet of agents (e.g. the Vehicle Routing Problem). However, when trying to do both simultaneously, the literature appears to still be in its infancy. Such a simultaneous planning seems promising: more preventive work can get done, and if tasks are chosen that are spread well, then the spread of agents can be better than if they are bunched together at the same response station. In Chapter 2, the Median Routing Problem is introduced as a model to compute how to visit plannable jobs in a graph in a fixed-length time horizon using a fleet of emergency response agents, while minimising the expected response time to the next emergency in the graph. Aside from an exponential-time algorithm that can compute the optimal solution, heuristics are developed that can be used in practice. Most notably, the MDSA-algorithm is found to be an effective heuristic: on benchmark instances, including case study data, it finds a solution in 2.4 seconds on average, which is on average only 3.2% away from optimal. Because it is NP-complete to decide for the Median Routing Problem whether a feasible solution exists, it makes no sense to develop a polynomial-time approximation algorithm for the general problem. Instead, in Chapter 3, a special version is studied in the form of the (Uniform) Travelling k-Median Problem.

Download or read book A study of algorithms for the k median problem and the vehicle routing problem written by Sang-Hyung Ahn and published by . This book was released on 1985 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Vehicle Routing Problem Latest Advances and New Challenges written by Bruce L. Golden and published by Springer. This book was released on 2010-11-25 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: In a unified and carefully developed presentation, this book systematically examines recent developments in VRP. The book focuses on a portfolio of significant technical advances that have evolved over the past few years for modeling and solving vehicle routing problems and VRP variations. Reflecting the most recent scholarship, this book is written by one of the top research scholars in Vehicle Routing and is one of the most important books in VRP to be published in recent times.

Download or read book Vehicle Routing written by Paolo Toth and published by SIAM. This book was released on 2014-12-05 with total page 467 pages. Available in PDF, EPUB and Kindle. Book excerpt: Vehicle routing problems, among the most studied in combinatorial optimization, arise in many practical contexts (freight distribution and collection, transportation, garbage collection, newspaper delivery, etc.). Operations researchers have made significant developments in the algorithms for their solution, and Vehicle Routing: Problems, Methods, and Applications, Second Edition reflects these advances. The text of the new edition is either completely new or significantly revised and provides extensive and complete state-of-the-art coverage of vehicle routing by those who have done most of the innovative research in the area; it emphasizes methodology related to specific classes of vehicle routing problems and, since vehicle routing is used as a benchmark for all new solution techniques, contains a complete overview of current solutions to combinatorial optimization problems. It also includes several chapters on important and emerging applications, such as disaster relief and green vehicle routing.

Download or read book The Service Routing Problem written by Nadine Holtvogt and published by Kölner Wissenschaftsverlag. This book was released on 2011 with total page 206 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Facility Location written by Reza Zanjirani Farahani and published by Springer Science & Business Media. This book was released on 2009-07-09 with total page 547 pages. Available in PDF, EPUB and Kindle. Book excerpt: Location problems establish a set of facilities (resources) to minimize the cost of satisfying a set of demands (customers) with respect to a set of constraints. This book deals with location problems. It considers the relationship between location problems and other areas such as supply chains.

Download or read book Vehicle Routing written by Paolo Toth and published by . This book was released on 2015 with total page 463 pages. Available in PDF, EPUB and Kindle. Book excerpt: Vehicle routing problems, among the most studied in combinatorial optimization, arise in many practical contexts (freight distribution and collection, transportation, garbage collection, newspaper delivery, etc.). Operations researchers have made significant developments in the algorithms for their solution, and Vehicle Routing: Problems, Methods, and Applications, Second Edition reflects these advances. The text of the new edition is either completely new or significantly revised and provides extensive and complete state-of-the-art coverage of vehicle routing by those who have done most of the innovative research in the area; emphasizes methodology related to specific classes of vehicle routing problems and, since vehicle routing is used as a benchmark for all new solution techniques, contains a complete overview of current solutions to combinatorial optimization problems; includes several chapters on important and emerging applications, such as disaster relief and green vehicle routing.

Download or read book The Vehicle Routing Problem written by Paolo Toth and published by . This book was released on 2002 with total page 367 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Periodical Vehicle Routing Problem Research Overview and Practical Application to a South German Fast Food Restaurant written by Claus Friedrich and published by GRIN Verlag. This book was released on 2006-03-29 with total page 159 pages. Available in PDF, EPUB and Kindle. Book excerpt: Diploma Thesis from the year 2005 in the subject Business economics - General, grade: 1,3, University of Augsburg, language: English, abstract: In the middle of May 1997 Gerd Raupeter, CEO of McDonald’s Deutschland Inc. (Mc Donald’s Germany Inc.), had to announce that some restaurants were sold out of shrimps1. The keen customer’s demand for this kind of seafood already exceeded the expected forecasts one week after starting the ongoing “Fisch-Wochen” (fish-weeks) mission. As these circumstances highlighted an accurate product choice for the fast food corporation Mr. Raupeter has nevertheless been pleased about it. Otherwise, such an awkward situation could be prevented by developing a demand-driven scheduling for each restaurant in the future. The Periodic(al) Vehicle Routing Problem (PVRP) seems to be a tailor-made solution for the reason that exact planning has to be done and “...delivery routes must be constructed over a period of time (for example, multiple days).” Observations and analyzes in the literature in most of the industries deal with a constant demand for goods and with only one good. Moreover the one-of-a-kind client prevails. But for the application of the PVRP to the gastronomy there are some exceptions to be considered. As this paper presents a solution approach of the delivery problem for the fast-food industry in South Germany, there are products to be transported consisting of diverse components. Although there are nearly identical opening hours, the eating places – the clientele to be delivered - due to their irregular demand for food and beverages are varying from the unique purchaser. Another singularity lies in the conformity of the foodstuff which is reflected in the comparability of each restaurant. Therefore the enduring solution approach will be done in a sample of some fast food restaurants. This paper herein is organized as follows. In the second and third chapter, various theories that could lead depots how to organize its delivery are reviewed, with an emphasis on the Vehicle Routing Problem (VRP) as well as the PVRP.

Download or read book Approximation Randomization and Combinatorial Optimization Algorithms and Techniques written by Leslie Ann Goldberg and published by Springer Science & Business Media. This book was released on 2011-08-05 with total page 715 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book constitutes the joint refereed proceedings of the 14th International Workshop on Approximation Algorithms for Combinatorial Optimization Problems, APPROX 2011, and the 15th International Workshop on Randomization and Computation, RANDOM 2011, held in Princeton, New Jersey, USA, in August 2011. The volume presents 29 revised full papers of the APPROX 2011 workshop, selected from 66 submissions, and 29 revised full papers of the RANDOM 2011 workshop, selected from 64 submissions. They were carefully reviewed and selected for inclusion in the book. In addition two abstracts of invited talks are included. APPROX focuses on algorithmic and complexity issues surrounding the development of efficient approximate solutions to computationally difficult problems. RANDOM is concerned with applications of randomness to computational and combinatorial problems.

Download or read book Transportation Network Analysis and Decomposition Methods written by Thomas L. Magnanti and published by . This book was released on 1978 with total page 218 pages. Available in PDF, EPUB and Kindle. Book excerpt: Application to freight flow problems, multifleet routing problems and vehicle routing problems.

Download or read book Bio inspired Algorithms for the Vehicle Routing Problem written by Francisco Baptista Pereira and published by Springer. This book was released on 2008-09-10 with total page 224 pages. Available in PDF, EPUB and Kindle. Book excerpt: The vehicle routing problem (VRP) is one of the most famous combinatorial optimization problems. In simple terms, the goal is to determine a set of routes with overall minimum cost that can satisfy several geographical scattered - mands. A ?eet of vehicles located in one or more depots is available to ful?ll the requests. A large number of variants exist, adding di?erent constraints to the original de?nition. Some examples are related to the number of depots, the ordering for visiting the customers or to time windows specifying a desirable period to arrive to a given location. The original version of this problem was proposed by Dantzig and Ramser in 1959 [1]. In their seminal paper, the authors address the calculation of a set of optimal routes for a ?eet of gasoline delivery trucks. Since then, the VRP has attractedtheattentionofalargenumberofresearchers.Aconsiderablepartofits success is a consequence of its practical interest, as it resembles many real-world problems faced everyday by distribution and transportation companies, just to mention a few applications areas. In this context, the development of e?cient optimization techniques is crucial. They are able to provide new and enhanced solutionstologisticoperations,andmaythereforeleadtoasubstantialreduction in costs for companies. Additionally, and from a research oriented perspective, the VRP is a challenging NP-hard problem providing excellent benchmarks to access the e?ciency of new global optimization algorithms.

Download or read book Time dependent Routing written by Rabie Jaballah and published by . This book was released on 2022 with total page 108 pages. Available in PDF, EPUB and Kindle. Book excerpt: The vehicle routing problem (VRP), introduced more than 60 years ago, is at the core of transportation systems. With decades of development, the VRP is one of the most studied problems in the literature, with a very rich set of variants. Yet, primarily due to the lack of data, two critical assumptions make the VRP fail to adapt effectively to traffic and congestion. The first assumption considers that the travel speed is constant over time ; the second, that each pair of customers is connected by an arc, ignoring the underlying street network. Traffic congestion is one of the biggest challenges in transportation systems. As traffic directly affects transportation activities, the whole supply chain needs to adjust to this factor. The continuous growth of freight in recent years worsens the situation, and a renewed focus on mobility, environment, and city logistics has shed light on these issues. Recently, advances in communications and real-time data acquisition technologies have made it possible to collect vehicle data such as their location, acceleration, driving speed, deceleration, etc. With the availability of this data, one can question the way we define, model, and solve transportation problems. This allows us to overcome the two issues indicated before and integrate congestion information and the whole underlying street network. We start by considering the whole underlying street network, which means we have customer nodes and intermediate nodes that constitute the street network. Then, we model the travel time of each street during the day. By dividing the day into small intervals, up to a precision of a second, we consider precise traffic information. This results in a new problem called the time-dependent shortest path vehicle routing problem (TD-SPVRP), in which we combine the time-dependent shortest path problem (TD-SPP) and the time-dependent VRP (TD-VRP), creating a more general and very challenging problem. The TD-SPVRP is closer to what can be found in real-world conditions, and it constitutes the topic of Chapter 2, where we formulate it as a mixed-integer linear programming model and design a fast and efficient heuristic algorithm to solve this problem. We test it on instances generated from actual traffic data from the road network in Québec City, Canada. Results show that the heuristic provides high-quality solutions with an average gap of only 5.66%, while the mathematical model fails to find a solution for any real instance. To solve the challenging problem, we emphasize the importance of a high-performance implementation to improve the speed and the execution time of the algorithms. Still, the problem is huge especially when we work on a large area of the underlying street network alongside very precise traffic data. To this end, we use different techniques to optimize the computational effort to solve the problem while assessing the impact on the precision to avoid the loss of valuable information. Two types of data aggregation are developed, covering two different levels of information. First, we manipulated the structure of the network by reducing its size, and second by controlling the time aggregation level to generate the traffic data, thus the data used to determine the speed of a vehicle at any time. For the network structure, we used different reduction techniques of the road graph to reduce its size. We studied the value and the trade-off of spatial information. Solutions generated using the reduced graph are analyzed in Chapter 3 to evaluate the quality and the loss of information from the reduction. We show that the transformation of the TD-SPVRP into an equivalent TD-VRP results in a large graph that requires significant preprocessing time, which impacts the solution quality. Our development shows that solving the TD-SPVRP is about 40 times faster than solving the related TD-VRP. Keeping a high level of precision and successfully reducing the size of the graph is possible. In particular, we develop two reduction procedures, node reduction and parallel arc reduction. Both techniques reduce the size of the graph, with different results. While the node reduction leads to improved reduction in the gap of 1.11%, the parallel arc reduction gives a gap of 2.57% indicating a distortion in the reduced graph. We analyzed the compromises regarding the traffic information, between a massive amount of very precise data or a smaller volume of aggregated data with some potential information loss. This is done while analyzing the precision of the aggregated data under different travel time models, and these developments appear in Chapter 4. Our analysis indicates that a full coverage of the street network at any time of the day is required to achieve a high level of coverage. Using high aggregation will result in a smaller problem with better data coverage but at the cost of a loss of information. We analyzed two travel time estimation models, the link travel model (LTM) and the flow speed model (FSM). They both shared the same performance when working with large intervals of time (120, 300, and 600 seconds), thus a higher level of aggregation, with an absolute average gap of 5.5% to the observed route travel time. With short periods (1, 10, 30, and 60 seconds), FSM performs better than LTM. For 1 second interval, FSM gives an average absolute gap of 6.70%, while LTM provides a gap of 11.17%. This thesis is structured as follows. After a general introduction in which we present the conceptual framework of the thesis and its organization, Chapter 1 presents the literature review for the two main problems of our development, the shortest path problem (SPP) and the VRP, and their time-dependent variants developed over the years. Chapter 2 introduces a new VRP variant, the TD-SPVRP. Chapter 3 presents the different techniques developed to reduce the size of the network by manipulating spatial information of the road network. The impact of these reductions is evaluated and analyzed on real data instances using multiple heuristics. Chapter 4 covers the impact of time aggregation data and travel time models when computing travel times on the precision of their estimations against observed travel times. The conclusion follows in the last chapter and presents some research perspectives for our works.

Download or read book Parallel Algorithms for Multi layer Wire Routing Problems written by Venkateswaran Ramachandran and published by . This book was released on 1994 with total page 348 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Metaheuristics for Vehicle Routing Problems written by Nacima Labadie and published by John Wiley & Sons. This book was released on 2016-02-10 with total page 194 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is dedicated to metaheuristics as applied to vehicle routing problems. Several implementations are given as illustrative examples, along with applications to several typical vehicle routing problems. As a first step, a general presentation intends to make the reader more familiar with the related field of logistics and combinatorial optimization. This preamble is completed with a description of significant heuristic methods classically used to provide feasible solutions quickly, and local improvement moves widely used to search for enhanced solutions. The overview of these fundamentals allows appreciating the core of the work devoted to an analysis of metaheuristic methods for vehicle routing problems. Those methods are exposed according to their feature of working either on a sequence of single solutions, or on a set of solutions, or even by hybridizing metaheuristic approaches with others kind of methods.

Download or read book Heuristics for Solving Three Routing Problems written by William Kenneth Mennell and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Operational Impacts of Median Width on Larger Vehicles written by Douglas W. Harwood and published by Transportation Research Board. This book was released on 2000 with total page 80 pages. Available in PDF, EPUB and Kindle. Book excerpt: This synthesis report will be of interest to officials and staff of municipal, regional, and statewide transportation agencies responsible for roadway design and traffic control. It will be of special interest to those concerned with intersections and driveways on divided highways where larger vehicles encounter narrow medians. It will also be of interest to other professionals who interact with these agencies to mitigate such problems. This report presents state-of-the-practice information about current median design policies and practices, describes the traffic operational and safety problems encountered in designing for larger vehicles at divided highway intersections, and identifies alternative improvement techniques that can be used in new construction or reconstruction projects to avoid introducing traffic operational and safety problems. This TRB report focuses on 10 alternative cross sections widely used on arterial highways in urban, suburban, and rural environment.