225,905 research outputs found
An ACO-Inspired, Probabilistic, Greedy Approach to the Drone Traveling Salesman Problem
In recent years, major companies have done research on using drones for parcel delivery. Research has shown that this can result in significant savings, which has led to the formulation of various truck and drone routing and scheduling optimization problems. This paper explains and analyzes a new approach to the Drone Traveling Salesman Problem (DTSP) based on ant colony optimization (ACO).
The ACO-based approach has an acceptance policy that maximizes the usage of the drone. The results reveal that the pheromone causes the algorithm to converge quickly to the best solution. The algorithm performs comparably to the MIP model, CP model, and EA of Rich & Ham (2018), especially in instances with a larger number of stops
High-Level Object Oriented Genetic Programming in Logistic Warehouse Optimization
DisertaÄŤnĂ práce je zaměřena na optimalizaci prĹŻbÄ›hu pracovnĂch operacĂ v logistickĂ˝ch skladech a distribuÄŤnĂch centrech. HlavnĂm cĂlem je optimalizovat procesy plánovánĂ, rozvrhovánĂ a odbavovánĂ. JelikoĹľ jde o problĂ©m patĹ™ĂcĂ do tĹ™Ădy sloĹľitosti NP-teĹľkĂ˝, je vĂ˝poÄŤetnÄ› velmi nároÄŤnĂ© nalĂ©zt optimálnĂ Ĺ™ešenĂ. MotivacĂ pro Ĺ™ešenĂ tĂ©to práce je vyplnÄ›nĂ pomyslnĂ© mezery mezi metodami zkoumanĂ˝mi na vÄ›deckĂ© a akademickĂ© pĹŻdÄ› a metodami pouĹľĂvanĂ˝mi v produkÄŤnĂch komerÄŤnĂch prostĹ™edĂch. Jádro optimalizaÄŤnĂho algoritmu je zaloĹľeno na základÄ› genetickĂ©ho programovánĂ Ĺ™ĂzenĂ©ho bezkontextovou gramatikou. HlavnĂm pĹ™Ănosem tĂ©to práce je a) navrhnout novĂ˝ optimalizaÄŤnĂ algoritmus, kterĂ˝ respektuje následujĂcĂ optimalizaÄŤnĂ podmĂnky: celkovĂ˝ ÄŤas zpracovánĂ, vyuĹľitĂ zdrojĹŻ, a zahlcenĂ skladovĂ˝ch uliÄŤek, kterĂ© mĹŻĹľe nastat bÄ›hem zpracovánĂ ĂşkolĹŻ, b) analyzovat historická data z provozu skladu a vyvinout sadu testovacĂch pĹ™ĂkladĹŻ, kterĂ© mohou slouĹľit jako referenÄŤnĂ vĂ˝sledky pro dalšà vĂ˝zkum, a dále c) pokusit se pĹ™edÄŤit stanovenĂ© referenÄŤnĂ vĂ˝sledky dosaĹľenĂ© kvalifikovanĂ˝m a trĂ©novanĂ˝m operaÄŤnĂm manaĹľerem jednoho z nejvÄ›tšĂch skladĹŻ ve stĹ™ednĂ EvropÄ›.This work is focused on the work-flow optimization in logistic warehouses and distribution centers. The main aim is to optimize process planning, scheduling, and dispatching. The problem is quite accented in recent years. The problem is of NP hard class of problems and where is very computationally demanding to find an optimal solution. The main motivation for solving this problem is to fill the gap between the new optimization methods developed by researchers in academic world and the methods used in business world. The core of the optimization algorithm is built on the genetic programming driven by the context-free grammar. The main contribution of the thesis is a) to propose a new optimization algorithm which respects the makespan, the utilization, and the congestions of aisles which may occur, b) to analyze historical operational data from warehouse and to develop the set of benchmarks which could serve as the reference baseline results for further research, and c) to try outperform the baseline results set by the skilled and trained operational manager of the one of the biggest warehouses in the middle Europe.
Assessing dynamic models for high priority waste collection in smart cities
Waste Management (WM) represents an important part of Smart Cities (SCs) with significant impact on modern societies. WM involves a set of processes ranging from waste collection to the recycling of the collected materials. The proliferation of sensors and actuators enable the new era of Internet of Things (IoT) that can be adopted in SCs and help in WM. Novel approaches that involve dynamic routing models combined with the IoT capabilities could provide solutions that outperform existing models. In this paper, we focus on a SC where a number of collection bins are located in different areas with sensors attached to them. We study a dynamic waste collection architecture, which is based on data retrieved by sensors. We pay special attention to the possibility of immediate WM service in high priority areas, e.g., schools or hospitals where, possibly, the presence of dangerous waste or the negative effects on human quality of living impose the need for immediate collection. This is very crucial when we focus on sensitive groups of citizens like pupils, elderly or people living close to areas where dangerous waste is rejected. We propose novel algorithms aiming at providing efficient and scalable solutions to the dynamic waste collection problem through the management of the trade-off between the immediate collection and its cost. We describe how the proposed system effectively responds to the demand as realized by sensor observations and alerts originated in high priority areas. Our aim is to minimize the time required for serving high priority areas while keeping the average expected performance at high level. Comprehensive simulations on top of the data retrieved by a SC validate the proposed algorithms on both quantitative and qualitative criteria which are adopted to analyze their strengths and weaknesses. We claim that, local authorities could choose the model that best matches their needs and resources of each city
A Hybrid Genetic Algorithm for the Traveling Salesman Problem with Drone
This paper addresses the Traveling Salesman Problem with Drone (TSP-D), in
which a truck and drone are used to deliver parcels to customers. The objective
of this problem is to either minimize the total operational cost (min-cost
TSP-D) or minimize the completion time for the truck and drone (min-time
TSP-D). This problem has gained a lot of attention in the last few years since
it is matched with the recent trends in a new delivery method among logistics
companies. To solve the TSP-D, we propose a hybrid genetic search with dynamic
population management and adaptive diversity control based on a split
algorithm, problem-tailored crossover and local search operators, a new restore
method to advance the convergence and an adaptive penalization mechanism to
dynamically balance the search between feasible/infeasible solutions. The
computational results show that the proposed algorithm outperforms existing
methods in terms of solution quality and improves best known solutions found in
the literature. Moreover, various analyses on the impacts of crossover choice
and heuristic components have been conducted to analysis further their
sensitivity to the performance of our method.Comment: Technical Report. 34 pages, 5 figure
- …