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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

Dynamische Tourenplanung - Modifikation von klassischen Heuristiken für das Dynamische Rundreiseproblem (DTSP) und das Dynamische Tourenplanungsproblem (DVRP) mit der Möglichkeit der Änderung des aktuellen Fahrzeugzuges

Richter, Andreas 19 September 2006 (has links) (PDF)
Unternehmen der Transportbranche müssen gerade im operativen Tagesgeschäft bei der Tourenplanung und Transportdisposition Planungsprobleme lösen, die ein hohes Maß an Dynamik aufweisen. Speziell die Inputfaktoren der Tourenplanung sind größtenteils dynamisch und stochastisch. Aus Sicht des Autors kann die Qualität von Tourplanungsergebnissen durch die zeitnahe Berücksichtigung unvorhergesehener Ereignisse nachhaltig verbessert werden. Jedoch findet diese zunehmend erfolgskritische Funktionalität in der Literatur bisher nur unzureichend Beachtung, obwohl das Tourenplanungsproblem (Vehicle Routing Problem (VRP)) eines der wichtigsten und am meisten erforschten kombinatorischen Optimierungsprobleme ist. Verfahren für kapazitierte dynamische Tourenplanungsproblemstellungen sind in der Literatur kaum zu finden. Speziell im Bereich der Algorithmen, die eine große Lösungsgeschwindigkeit, eine leichte Verständlichkeit, eine aus praktischer Sicht akzeptable Lösungsgüte aufweisen und die Möglichkeit besitzen, die aktuellen Routenpläne der Fahrzeuge ausgehend von der momentanen geographischen Position real-time zu verändern, besteht Forschungsbedarf. Die Arbeit geht daher der Forschungsfrage nach, wie ein Verfahren für die dynamische Tourenplanung zu konstruieren ist, welches das kapazitierte dynamische Tourenplanungsproblem mit der Möglichkeit der Änderung des aktuellen Fahrzeugzuges unter Einhaltung sehr kurzer Rechenzeiten bei größtmöglicher Verständlichkeit löst. Durch die genannten Kriterien wird im Rahmen der Arbeit der Schwerpunkt auf die Modifikation von klassischen heuristischen Verfahren für die Lösung von dynamischen Tourenplanungsproblemen gelegt. Die Arbeit befasst sich sowohl mit dem Gesamtkonzept zur Disposition dynamischer Kunden als auch mit konkreten Modellen und Verfahren zur Lösung von Subproblemen innerhalb des Gesamtkonzeptes. Ferner erfolgt die Präsentation von umfangreichen Simulationsergebnissen, die auf der durchgeführten softwaretechnischen Implementierung der entwickelten Verfahren basieren. Die gute Anwendbarkeit der neuen Verfahren in der Praxis wird gezeigt. Zwecks der möglichst ganzheitlichen Betrachtung des Themengebietes erfolgt in der Arbeit zum einen sowohl die Erörterung von quantitativen als auch von qualitativen Aspekten der dynamischen Tourenplanung und zum anderen die Analyse von Schnittstellen zwischen der dynamischen Tourenplanung und eng damit verbundenen Bereichen wie Flottenmanagement oder Auftragseingang bzw. -disposition. Hierzu werden die Informationsflüsse zwischen den beteiligten Elementen im Rahmen des dynamischen Dispositionsprozesses aufgezeigt, telematische Komponenten zur Unterstützung des Informationsmanagements und der Informationsübertragung vorgestellt sowie die benötigten Inputdaten erläutert. Den Schwerpunkt der Arbeit stellt jedoch die Entwicklung von neuen quantitativen Methoden zur dynamischen Tourenplanung dar.
22

Capacitated Vehicle Routing Problem with Time Windows: A Case Study on Pickup of Dietary Products in Nonprofit Organization

January 2015 (has links)
abstract: This thesis presents a successful application of operations research techniques in nonprofit distribution system to improve the distribution efficiency and increase customer service quality. It focuses on truck routing problems faced by St. Mary’s Food Bank Distribution Center. This problem is modeled as a capacitated vehicle routing problem to improve the distribution efficiency and is extended to capacitated vehicle routing problem with time windows to increase customer service quality. Several heuristics are applied to solve these vehicle routing problems and tested in well-known benchmark problems. Algorithms are tested by comparing the results with the plan currently used by St. Mary’s Food Bank Distribution Center. The results suggest heuristics are quite completive: average 17% less trucks and 28.52% less travel time are used in heuristics’ solution. / Dissertation/Thesis / Masters Thesis Industrial Engineering 2015
23

Strategické rozhodnutí společnosti Baťa, a.s. / Strategical decision of Baťa a.s.

Plášková, Pavlína January 2008 (has links)
In this thesis we report several of delivery problems. Here it is mostly describe Vehicle Routing Problem and Split Delivery Problem as suitable methods for the case study of the company Baťa a.s.In this thesis we used one of the most sofisticated software Roadnet Transportation Suite as effective program for distribution and planning routes.Finally we construct analysis as a support to find the optimal solution for the final strategical decision of the company Baťa a.s.
24

Modelling and Optimization of Simultaneous Froward- and Reverse Logistics as Capacitated Vehicle Routing Problem : An optimization simulation model problem

Islam, Md Kamrul January 2022 (has links)
Environmental issues are a vital concern in today’s world. The Swedish government and local businesses are developing a sustainable business and eco-friendly environment for city inhabitants. Last-mile pickup and delivery services are a key concern, which significantly impacts the environment and society. The Norwegian/Swedish parcel delivery company Bring, the reusable waste management company Ragn-Sells, the city of Stockholm, the research institute Sustainable Innovation, and the KTH Royal Institute of Technology are jointly working together in the Intercitylog2 project with a vision to handle better last-mile pickups or deliveries that are jointly serviced by small electric vehicles from an urban micro terminal. This thesis addresses the optimizations of simultaneous pickup and delivery operations using homogeneous vehicles and considering vehicle capacity, time windows and environmental constraints. A mathematical model is developed to address the problem using an exact commercial solver. The quality of the solutions has been evaluated with real pickup and deliveries of the participating company. The primary objective function is formulated to minimize the travel cost by finding the shortest path, and the results are compared with current routing operation data. KPIs are developed and evaluated based on the facts and figures from the obtained results of the experiments. The two scenarios, big vehicles and small vehicles are also developed and evaluated to find the best route optimization opportunity for the companies. The results show that the optimized operation could decrease delivery distance by 36.72% and 37.13% and delivery time by 43.65% and 47.08% for big and small vehicles operations, respectively, compared to the current routing operations. A round trip can complete within a defined time frame to avoid the battery running out during a route. Energy constraints demonstrate that using electric vehicles considerably reduce significant amounts of CO2 emission from the environment. / Miljöfrågor är en viktig fråga i dagens värld. Den svenska regeringen och lokala företag arbetar tillsammans för att utveckla ett hållbart företagande och miljövänlig miljö för stadens invånare. Last-mile hämtning och leveranstjänster är en viktig fråga, som avsevärt påverkar miljön och samhället.Det norsk/svenska paketleveransföretaget Bring, återanvändbara avfallshanteringsföretaget Ragn- Sells, Stockholms stad, forskningsinstitutet Sustainable Innovation och Kungliga Tekniska Högskolan arbetar tillsammans i Intercitylog2-projektet för en vision för att bättre hantera last-mile pickuper eller leveranser som gemensamt betjänas av små elfordon från en urban mikroterminal. Detta examensarbete behandlar optimering av samtidiga hämtnings- och leveransoperationer med homogena fordon och med hänsyn till fordonskapacitet, tidsfönster och miljömässiga begränsningar. En matematisk modell utvecklas för att ta itu med problemet med en exakt kommersiell lösare och kvaliteten på lösningarna har utvärderats med verklig upphämtning och leveranser från det deltagande företaget. Den primära målfunktionen är formulerad för att minimera reskostnaden genom att hitta den kortaste vägen, och resultaten jämförs med aktuella ruttoperationsdata. KPI:er utvecklas och utvärderas utifrån fakta och siffror från de erhållna resultaten av experimenten. De två scenarierna, stora fordon och små fordon, är också utvecklade och utvärderade för att hitta den bästa ruttoptimeringsmöjligheten för företagen. Resultaten visar att den optimerade driften kan minska leveransavståndet med 36,72% och 37,13% och leveranstiden med 43,65% och 47,08% för stora och små fordonsoperationer, jämfört med nuvarande ruttoperationer. En tur och retur kan genomföras inom en definierad tidsram för att undvika att batteriet tar slut under en rutt. Energibegränsningar visar att användning av elfordon avsevärt minskar betydande mängder CO2-utsläpp från miljön.
25

Planejamento de rotas dirigidas com base no problema de roteamento humano

Rodrigues, Rafael Emidio Murata 30 August 2018 (has links)
Submitted by Filipe dos Santos (fsantos@pucsp.br) on 2018-10-19T11:51:51Z No. of bitstreams: 1 Rafael Emídio Murata Rodrigues.pdf: 1071545 bytes, checksum: 468e0f7e27e278e12eed0dd52f4198cc (MD5) / Made available in DSpace on 2018-10-19T11:51:51Z (GMT). No. of bitstreams: 1 Rafael Emídio Murata Rodrigues.pdf: 1071545 bytes, checksum: 468e0f7e27e278e12eed0dd52f4198cc (MD5) Previous issue date: 2018-08-30 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / In our lives, we constantly move in streets and neighborhoods. In general, we consider time and (or distance) when planning the route. However, their solutions may face complex problems arising from the different possibilities of solutions. Similar to route planning, the Vehicle Routing Problem was introduced by George B. Dantzig and John H. Ramser in 1959 and consists of delivering gasoline to several fuel stations; at first a mathematical proposal, later became an algorithmic approach, for planning of routes of delivery of products in an optimized way (searching the "shortest path"). Although, during the search of shortest path, they are limited to the use of the streets. In this context emerges the Human Routing Problem, such an approach is not limited to streets, but makes use of all possible paths, by vehicles and humans. Such a problem can be observed in route planning at airports, museums and a supply chain company that wants to optimize the route of delivery of its products and increase customer satisfaction. Based on the Vehicle Routing Problem, the Human Routing Problem will be proposed. Its problematic will be demonstrated in a prototype, capable of assisting in the planning of human routes and three use cases. Ideas of Human Routing Problem had inspiration in the collective foraging insects / Na nossa vida, nos locomovemos constantemente em ruas e bairros. Em geral, consideramos o tempo e (ou a distância), ao planejar a rota. Contudo, suas soluções podem enfrentar problemas complexos, decorrentes das diversas possibilidades de soluções. Semelhante a planejamento de rotas, o Problema de Roteamento de Veículos foi introduzido por George B. Dantzig, e John H. Ramser em 1959 e consiste em entregar gasolina diversos postos de combustível; a princípio uma proposta matemática, mais tarde tornou-se uma abordagem algorítmica, para planejamento de rotas de entrega de produtos de forma otimizada (buscando o “menor caminho”). Embora, durante a busca de menor caminho, limitam-se ao uso de ruas. Neste contexto emerge o Problema de Roteamento Humano, tal abordagem não se limita a ruas, mas faz uso de todos os caminhos possíveis, por veículos e humanos. Tal problemática, pode ser observada nos planejamentos de rotas em aeroportos, museus e em uma empresa de supply chain que deseja otimizar a rota de entrega dos seus produtos, e aumentar a satisfação dos seus clientes. Tomando como base central, o Problema de Roteamento de Veículos será proposto o Problema de Roteamento Humano. Sua problemática, será demonstrado em um protótipo, capaz de auxiliar no planejamento de rotas humanas e três casos de uso. As ideias do Problema de Roteamento Humano tiveram inspiração no forrageamento dos insetos coletivos
26

Modelo matemático para apoio à gestão da logística de empregados de plataformas offshore de exploração de petróleo

Machado, André Manhães 16 November 2013 (has links)
Made available in DSpace on 2016-12-23T14:21:18Z (GMT). No. of bitstreams: 1 Andre Manhaes Machado.pdf: 1039285 bytes, checksum: 2b356c4d0279c975232bd92c5e2ab326 (MD5) Previous issue date: 2013-11-16 / O petróleo é a principal fonte energética do mundo contemporâneo, insumo básico de diversos setores econômicos. Com a descoberta do Pré-sal, o Brasil tem a oportunidade de tornar-se um dos maiores produtores de petróleo. Entretanto, para que isso seja alcançado, vários desafios deverão ser superados e, dentre eles, encontra-se o problema de transporte de empregados para operarem as plataformas offshore, distantes até 300km de distância da costa brasileira. Os problemas referentes ao deslocamento de empregados por meio de helicópteros são usualmente tratados como o Capacitated Helicopter Routing Problem (CHRP). Com base nas restrições de origem e de destino de cada cliente, no número de veículos e na capacidade e restrições de voo dos helicópteros, neste tipo de problema deseja-se minimizar os custos de aluguel de helicópteros mais o custo total de quilômetros voados. A presente dissertação propõe um modelo de Programação Linear Inteira Mista (PLIM) para o problema de roteirização de helicópteros com base no Dial-a-Ride Problem (DARP). Além do modelo apresentado, foram apresentados duas abordagens para a execução do modelo de forma exata: i) abordagem sem agrupamento, na qual as requisições que possuem origens iguais e destinos iguais são modeladas como requisições distintas e ii) abordagem com agrupamento, na qual requisições que possuem origens iguais e destinos iguais são aglutinados numa nova e única requisição. O modelo matemático foi executado no software CPLEX e os resultados mostraram que instâncias com até 25 requisições podem ser resolvidas pela abordagem com agrupamento / Oil is the main energy source of contemporary world; it is basic inputs of various economic sectors. With the discovery of Brazil pre-salt, there is an opportunity to become one of the largest oil producers. However, to achieve her own goals, Brazil must overcome several challenges, including the problem of transporting employees to operate offshore platforms 300km distant away from the Brazilian coast. Problems related to displacement of employees by helicopters are usually treated as Capacitated Helicopter Routing Problem (CHRP). Based on source and destination restrictions of each client, the number of vehicles, capacity and helicopter flight constraints, this type of problem proposes to minimize the cost of renting helicopters and the total cost of flown kilometers. This dissertation proposes a model of Mixed Integer Linear Programming (MILP) for the helicopters routing problem based on a Dial-a-Ride Problem (DARP). Besides the presented model, we presented two approaches to implementing the model in an exact way: i) non-clustered approach, in which requests that have the same origin and destination are equal modeled as separate requests; and ii) clustered approach, in which requests that have the same origins and destinations are clumped together in a new single request. The mathematical model was implemented in software CPLEX and results showed that instances with up to 25 requests can be resolved in the clustered approach
27

Parameter Tuning Experiments of Population-based Algorithms

Nilsson, Mikael January 2011 (has links)
In this study, three different algorithms are implemented to solve thecapacitated vehicle routing problem with and without time windows:ant colony optimization, a genetic algorithm and a genetic algorithmwith self-organizing map. For the capacitated vehicle routing problemthe Augerat et al’s benchmark problems were used and for the capaci-tated vehicle routing problem with time windows the Solomon’sbenchmark problems. All three algorithms were tuned over thirtyinstances per problem with the tuners SPOT and ParamILS. The tuningresults from all instances were combined to the final parameter valuesand tested on a larger set of instances. The test results were used tocompare the algorithms and tuners against each other. The ant colonyoptimization algorithm outperformed the other algorithms on bothproblems when considering all instances. The genetic algorithm withself-organizing map found more best known solutions than any otheralgorithm when using parameters, on the capacitated vehicle routingproblem. The algorithms performed well and several new best knownresults were discovered for the capacitated vehicle routing problem andnew best solutions found by heuristics were discovered for the 100customer Solomon problems. When comparing the tuners they bothworked well and no clear winner emerged.
28

Analys och optimering av transportflöden i Eskilstuna kommun : Eliminering av slöseri och dess effekter ur ett ekonomiskt- och miljöperspektiv

Deldar, Sam, Cizmeli, Gabriella January 2017 (has links)
Syfte: Att undersöka de potentiella fördelarna vid implementering av Lean-baserade metoder för att möta prestanda, tillgänglighet och effektivitet i transportsystemet samt användningen av en varuflödesplan för att identifiera slöseri. Vidare, att observera hur fördelarna med en ruttoptimering kan minimera slöseri och reducera kostnader relaterade till transport samt minskningen av miljöutsläpp, stadsbuller och säkerhet. Metod och genomförande: För att uppnå syftet med denna studie och att besvara forskningsfrågorna har en fallstudie och en litteraturstudie kombinerats och genomförts. Fallstudien innehåller observationer och intervjuer som har genomförts för att samla in information om hur fallföretaget arbetar med transport dagligen, användningen av standardisering och effektivisering samt hantering av ruttplanering. Vidare har en implementering utförts av de föreslagna ruttoptimeringsmetoderna för att få större förståelse för de föreslagna metoderna och litteraturen. Slutligen har en analys och diskussion genomförts där de empiriska resultaten studerats och jämförts med litteraturstudien. Resultat: Genomförandet av Lean-baserade metoder för att identifiera och minska slöseri baserat på prestationsmätningsverktyg, såsom värdeflödekartläggning och användningen av ruttoptimering, har visat flera fördelar. De identifierade fördelarna var kortare körtider för chaufförerna, en minskad total kilometersträcka, en mer optimerad fyllnadsgrad i lastbilarna samt mer effektiv tid vid lastning och lossning av gods. Den sistnämna fördelen påverkar främst tillgängligheten och prestandan av den totala fordon- och chaufförseffektiviteten. En del av fördelarna var tolkbara i monetära termer för att ge insikt om hur de eventuella kostnadsbesparingarna. Rekommendationer: För att få bättre och mer djupgående resultat i framtida studier, föreslås att: fallföretaget kartlägger alla transporter som utförs för att bedöma lönsamheten i vissa körrutter samt för att undersöka hur all transport kan uppdelas geografiskt med hjälp av presenterat material i denna studie; noggrannare observationer av förare under andra veckodagar för att identifiera ytterligare problemområden och förbättringsmöjligheter; standardisera och implementera Lean metoder i närliggande processer i verksamheten för fortsatt strävan efter en lönsam verksamhet, till exempel genom att granska mottagandet av varor från leverantörer och utvärdera möjligheten med att ha lokala leverantörer; slutligen, all personal ska utbilda sig inom Lean och standardiserat arbete för att ytterligare eliminera och minska interna NIT-aktiviteter, såsom väntetid. / Purpose: To explore the possible benefits with the implementation of Lean methods to measure performance, availability and efficiency in transportation, including the use of a value stream map to identify waste. Furthermore, to observe how the benefits with a route optimization eventually can minimize waste and reduce costs related to transportation as well as the reduction of environmental emissions, urban noise and security. Methodology: To achieve the purpose of this study and to solve the research questions, a case study and a literature study has been combined and carried out. The case study contains observations and interviews which has been executed in order to gather information related to how the case-company work with transportation on a daily basis, the usage of standardization and the management of route planning. Moreover, an implementation of the proposed route optimizations has been executed with the purpose of gaining knowledge related to the outcome. Finally, an analysis and discussion has been performed where the empirical results are studied and compared with the literature findings. Findings: The implementation of Lean methods to identify and reduce waste based on performance measuring tools, such as value stream mapping and the use of route optimization, showed several advantages. The identified advantages were shorter driving schedules for the chauffeurs, a reduced overall mile distance, a more optimal degree of filling in the driver trucks and more efficient time spent while loading and unloading the trucks. The last advantage mainly affecting the availability and performance of the overall vehicle efficiency. Some of the advantages were interpretable into monetary terms in order to provide an insight into any cost savings. Recommendations: To gain better and more profound results in any further studies, it is suggested that: the case company map out all transports carried out in order to assess the profitability of certain driving routes, as well as to examine how all transport can be geographically divided using the presented material in this study; more thorough observations of drivers during other weekdays to further identify problem areas and improvement opportunities ought to be done; standardization and implementation of Lean methods in related processes in the company for continued pursuit of profitable operations. For example, by reviewing the receipt of goods from suppliers and reviewing the option of having local suppliers; lastly, all staff gets training and education of Lean methods and standardized work for additional elimination and reduction of internal NIT activities, such as waiting time.
29

Optimalizace tras při rozvozu europalet / Optimal routes for Euro pallet transporting

Juříčková, Ivana January 2014 (has links)
This diploma thesis describes a logistic problem of the company JACER-CZ Ltd. The main focus is on identifying optimal routes about the Euro pallets distribution. The Euro pallets are standardized at length replaceable transport pallets which are in Europe. The aim of this thesis is to find a solution which will meet requirements of all thirteen customers and simultaneously a total route length of all vans will be minimalized. At first there is the mathematical model about the delivery assignment with the split delivery vehicle calculated by solvers CPLEX and Gurobi. Then the original and the modified example is solved manually by heuristic algorithms. It is concerned the nearest neighbour algorithm, savings algorithm, the insertion algorithm and the heuristic method for the split delivery vehicle routing problem.
30

Modely a metody pro svozové úlohy / Models and methods for routing problems

Nevrlý, Vlastimír January 2016 (has links)
This master's thesis deals with mathematical model building for routing problems and ways to solve them. There are discussed and implemented deterministic and heuristic approaches that are suitable to be utilized. A big effort is put into building of the mathematical model describing a real world problem from the field of waste management. Appropriate algorithms are developed and modified to solve a particular problem effectively. An original graphical environment is created to illustrate acquired results and perform testing computations.

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