Search results for "Heuristic"
showing 10 items of 476 documents
A Branch-and-Cut Algorithm for the Single Truck and Trailer Routing Problem with Satellite Depots
2016
International audience; In the single truck and trailer routing problem with satellite depots (STTRPSD), a truck with a detachable trailer based at a main depot must serve the demand of a set of customers accessible only by truck. Therefore, before serving the customers, it is necessary to detach the trailer in an appropriate parking place (called either a satellite depot or a trailer point) and transfer goods between the truck and the trailer. This problem has applications in milk collection for farms that cannot be reached using large vehicles. In this work we present an integer programming formulation of the STTRPSD. This formulation is tightened with several families of valid inequaliti…
A DGS gesture dictionary for modelling on mobile devices
2017
ABSTRACTInteractive or Dynamic Geometry System (DGS) is a tool that help to teach and learn geometry using a computer-based interactive environment. Traditionally, the interaction with DGS is based on keyboard and mouse events where the functionalities are accessed using a menu of icons. Nevertheless, recent findings suggest that such a traditional model of interaction has a steep learning curve and is inadequate to develop DGS for devices with multi-touch screens. Thus, we propose a new interaction model for DGS based on a gesture dictionary which enables the construction and manipulation of geometric objects without the need of accessing a menu of icons. The dictionary is divided into thr…
Crowdfunding Models, Strategies, and Choices Between Them
2020
AbstractThe growing popularity of crowdfunding is manifested through the proliferation of thousands of platforms globally. The current chapter presents an elaborate, up-to-date, and detailed typology of crowdfunding models currently in use, as well as their main characteristics. Furthermore, it suggests some of the first frameworks developed for guiding prospective fundraisers in choosing between models. Each of the frameworks is designed for a different type of fundraiser, including model choice heuristics for organizations and consumers. The chapter concludes with some suggestions for further research and implications for practice.
Different Methods of Artificial Intelligence Used for Optimization the Turning Process
2015
In this paper, we realize a comparative study between some heuristics methods applied in turning operation in order to find optimal cutting parameters. We consider five different constraints aimed to achieve minimum total cost of machining. We have chosen the Simulated Annealing (SA) – a local search method, and Weighted-Sum Genetic Algorithm (WSGA) – a non-Pareto approach of a multi-objective optimization algorithm, based on a weighted aggregation of objectives. The aggregation may be with fixed weights or with random (variable) weights. The simulations showed that, even if it produces better results than the SA, WSGA with fixed weights, does not lead to optimum results, highlighting in th…
Improved route planning and scheduling of waste collection and transport
2006
The collection of waste is a highly visible and important municipal service that involves large expenditures. Waste collection problems are, however, one of the most difficult operational problems to solve. This paper describes the optimization of vehicle routes and schedules for collecting municipal solid waste in Eastern Finland. The solutions are generated by a recently developed guided variable neighborhood thresholding metaheuristic that is adapted to solve real-life waste collection problems. Several implementation approaches to speed up the method and cut down the memory usage are discussed. A case study on the waste collection in two regions of Eastern Finland demonstrates that sign…
A Novel Artificial Mosaic Generation Technique Driven by Local Gradient Analysis
2008
Art often provides valuable hints for technological innovations especially in the field of Image Processing and Computer Graphics. In this paper we present a novel method to generate an artificial mosaic starting from a raster input image. This approach, based on Gradient Vector Flow computation and some smart heuristics, permit us to follow the most important edges maintaining at the same time high frequency details. Several examples and comparisons with other recent mosaic generation approaches show the effectiveness of our technique.
Search Interfaces and Learning about Controversial Topics
2019
Search engine results pages (SERPs) are a frequent gateway to Internet content. Prior research has extensively documented strong effects of SERPs (e.g. rank order or the spatial distribution of the results) on users' attention to and selection of particular Web pages [1,2]. In the context of Web search, a common user behavior is the 'top link' or 'Google trust' heuristic, that is, the inspection and selection of only the first few search results presented by the search engine, without evaluating all other search results available. This heuristic behavior allows users to find information in an efficient way, as search engines tend to provide relevant documents on top of the list, especially …
The nature of security and risk in complex socio-technical systems : a partial application of Critical Systems Heuristics (CSH) to Finnish Security S…
2011
Tämä tutkimus selventää suhteita turvallisuuden, riskien sekä kompleksisten sosio-teknisten järjestelmien välillä. Käsittely tapahtuu pääosin yhteiskunnallisella tasolla, mutta eri järjestelmiä ja niiden yleisiä sekä teoreettisia perusrakenteita tarkastellaan kokonaisuuden ymmärtämiseksi paremmin. Samalla pyritään parantamaan käsitystä niistä monista yhteisvaikutuksista joita eri järjestelmillä on toisiinsa ja miten ne vaikuttavat turvallisuuteen. Turvallisuus on tunnistettu olevan suhteellista ja käyttäytyvät eri tavalla todellisissa avoimissa järjestelmissä ja avoimessa järjestelmien ympäristössä, verrattuna yksinkertaisiin järjestelmiin. Teknologia on alati läsnä nykyaikaisissa kehittyne…
Drivers-Inspired Ants for Solving the Vehicle Routing Problem with Time Windows
2016
International audience; In our study, we develop a method that merges two information sources within ants colony optimization heuristic. Namely artificial ants which occurs for short term optimization and transporter's vehicles that occurs in long term and continuous optimization toward solving the real-world vehicle routing problem. This study is supported by a transporter (Upsilon) of the region of l'Yonne in France and a transport and logistics software development company (Tedies). Our method suits for transporters that use human planners to make decisions about their tours and intending to move to computer planners without drastically upsetting the drivers habits. Hence, the pledge of …
Scheduling independent stochastic tasks on heterogeneous cloud platforms
2019
International audience; This work introduces scheduling strategies to maximize the expected number of independent tasks that can be executed on a cloud platform within a given budget and under a deadline constraint. The cloud platform is composed of several types of virtual machines (VMs), where each type has a unitexecution cost that depends upon its characteristics. The amount of budget spent during the execution of a task on a given VM is the product of its execution length by the unit execution cost of that VM. The execution lengths of tasks follow a variety of standard probability distributions (exponential, uniform, halfnormal, etc.), which is known beforehand and whose mean and stand…