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  • Ant colony optimization routing mechanisms with bandwidth sensing
    Publication . Mapisse, J. M.; Cardoso, Pedro J. S.; Monteiro, J. M.
    The study and understanding of the social behavior of insects has contributed to the definition of some algorithms that are capable of solving several types of optimization problems. In 1997 Di Caro and Dorigo developed the first routing algorithm for wired networks, called AntNet, using an approach which was inspired in the behavior of ant colonies. At each node, AntNet, similar to others Ant Colony Optimization (ACO) based algorithms, forward ants based in the amount of pheromones present in the links and in response to the node's queue lengths. In this paper, an adaptation of the e-DANTE algorithm for discrete problems, as an IP based routing mechanism, was implemented. We also propose the inclusion of a new parameter for the computation of paths for both the AntNet and the newly proposed algorithm: the available bandwith. Those methods were tested in ns-2 using two dense network architectures and their efficiency is compared with the original AntNet and a Link-State routing algorithm, when considering the transmission of competing traffic flows between distinct nodes. © 2011 IEEE.
  • A solution for a real-time stochastic capacitated vehicle routing problem with time windows
    Publication . Cardoso, Pedro J. S.; Schütz, Gabriela; Mazayev, Andriy; Ey, Emanuel; Corrêa, Tiago
    Real-time distribution planning presents major difficulties when applied to large problems. Commonly, this planning is associated to the capacitated vehicle routing problem with time windows (CVRPTW), deeply studied in the literature. In this paper we propose an optimization system developed to be integrated with an existing Enterprise Resource Planning (ERP) without causing major disruption to the current distribution process of a company. The proposed system includes: a route optimization module, a module implementing the communications within and to the outside of the system, a non-relational database to provide local storage of information relevant to the optimization procedure, and a cartographic subsystem. The proposed architecture is able to deal with dynamic problems included in the specification of the project, namely: arrival of new orders while already optimizing as well as locking and closing of routes by the system administrator. A back-office graphical interface was also implemented and some results are presented.
  • Mobile five senses augmented reality system: technology acceptance study
    Publication . Rodrigues, João; Ramos, Celia; Pereira, Joao A. R.; Sardo, Joao D. P.; Cardoso, Pedro
    The application of the most recent technologies is fundamental to add value to tourism experiences, as well as in other economic sectors. Mobile Five Senses Augmented Reality (M5SAR) system is a mobile guide instrument for cultural, historical, and museum events. In order to realize the proclaimed five senses, the system has two main modules: a (i) mobile application which deals mainly with the senses of sight and hearing, using for that the mobile device camera to recognize and track on-the-fly (museum's) objects and give related information about them; and a (ii) portable device capable of enhancing the augmented reality (AR) experience to the full five senses through the stimulus of touch, taste, and smell, by associating itself to the users' smartphone or tablet. This paper briefly presents the system's architecture but, the main focus is on the analysis of the users' acceptance for this technology, namely the AR (software) application, and its integration with the (hardware) device to achieve the five senses AR. Results show that social influence, effort expectancy, and facilitating conditions are the key constructs that drive the users to accept and M5SAR's technology.
  • LifeSpeeder: a web and mobile platform for events location
    Publication . Cardoso, Pedro J. S.; Monteiro, J. M.; Dos Santos, J.; Baeza, N.; Tarazona, S.
    The use of smartphones and tablets as become almost banal in these days. Smartphones, besides serving their main purpose of making and receiving calls, come to be one of the main equipments to obtain information from the Internet, using the commonly installed browsers or through the use of dedicated applications. Furthermore, several other devices are also very frequent to the majority of the modern smartphones and tablets in the market (e.g., GPS - Global Positioning System). This devices give the current systems a very high potential of usage. One example of applicability, comes from the wish to find and navigate to events or activities which are or will soon be occurring near the user. The LifeSpeeder platform is one of the first applications in the mobile equipment market of applications which take into consideration exactly what we have just outlined, i.e., a mobile and desktop application which allows the users to locate events according with their preferences and to get help navigating to them. In this paper we briefly describe the LifeSpeeder's front and back-end. © 2014 Springer International Publishing.
  • Ant colony algorithms for multiple objective combinatorial optimization: applications to the minimum spanning trees problems
    Publication . Cardoso, Pedro J. S.
    The study of meta-heuristic solutions based on the Ant Colony Optimization (ACO) paradigm for the Multiple Objective Minimum Spanning Trees and related combinatorial problems is the main concern of this investigation. In the commonly accepted complexity scale for problems, the Multiple Objective Minimum Spanning Trees is rated as an $\NP$-complete problem. Furthermore, as in the generality of the multiple objective optimization problem, the solution of the Minimum Spanning Trees case is a set of trade-off solutions in the sense that to improve one of the objectives it is necessary to worse at least one of the others, which is a major concern in a practical point of view. In the first part of the investigation, a theoretical analysis of the problem is made to complement the known results. This analysis corroborates the fact that in practice the use of exact methods to solve the Multiple Objective Minimum Spanning Trees problems is only applied in specific circumstances. This implies that to solve the problem an approximation method must be considered as an alternative. In particular, two methods based on the ACO paradigm are proposed: the Multiple Objective Network optimization based on an ACO (MONACO) and the $\epsilon$-Depth ANT Explorer (e-DANTE). The MONACO method uses a set of pheromone trails and specific heuristics to approximate the Pareto set. The e-DANTE method is an improvement of the MONACO method that uses a depth search procedure, based on the best performing solutions, to deeply exploit the search space. The proposed methods are tested with selected multiple objective problems, improving the results previously obtained by other authors. To test the MONACO and e-DANTE algorithms over the Multiple Objective Minimum Spanning Trees problem is proposed a library/repository of multiple objective network problems established over a systematized set of networks generators. The results obtained with MONACO and e-DANTE are then compared with the results obtained with a Brute Force and the Weighted Sum method.
  • Framework for the characterization of hotel websites
    Publication . Correia, Marisol B.; Ramos, Célia M. Q.; Rodrigues, J. M. F.; Cardoso, Pedro J. S.
    Nowadays the importance of websites to the tourism and hospitality industries is fundamental. Hotels, for instance, spend a huge amount of money improving their websites to show all the activities and amenities that they can provide. There are studies to evaluate website performance based on functionality, usability and other factors; nevertheless, they are not exhaustive. This paper presents a framework for the characterization of hotel and resort websites, that was applied as a case study to the websites of 5-star hotels and resorts that operate in the tourism region of the Algarve, Portugal. This framework allows us to identify a set of features for the hotel and resort websites characterization. From these features, we propose a set of comprehensive indicators, grouping them into ten fundamental information dimensions, as well as the application of these indicators and information dimensions, which allows obtaining quantitative and qualitative results.
  • Augmented reality and holograms for the visualization of mechanical engineering parts
    Publication . Figueiredo, Mauro; Cardoso, Pedro J. S.; Gonçalves, C. D. F.; Rodrigues, J. M. F.
    There is an increasing number of students using tablets in schools. Mobile devices gained popularity as an educational tool and there are many schools that use them frequently in educational activities to improve learning. We found that first year students of mechanical engineering in general have difficulties in understanding 3D shapes from 2D views. There are many Augmented Reality (AR) applications available that can be used to create educational contents for these mobile devices. On the other hand, there is an increasing interest in making holograms. In this paper we studied the most popular AR systems and show examples of using an AR system for the visualization of 3D models. We also present the creation of a low cost prototype, the EducHolo, that enables the visualization of holograms supported by tablets. With this prototype students can visualize the hologram of mechanical parts, providing a better perception of the model 3D shape and improving the ability of making the 2D orthographic views and perspectives that they study in the first year of mechanical engineer.
  • epsilon-DANTE: an ant colony oriented depth search procedure
    Publication . Cardoso, Pedro J. S.; Jesus, Mário; Marquez, Alberto
    The epsilon-Depth ANT Explorer (epsilon-DANTE) algorithm applied to a multiple objective optimization problem is presented in this paper. This method is a hybridization of the ant colony optimization algorithm with a depth search procedure, putting together an oriented/limited depth search. A particular design of the pheromone set of rules is suggested for these kinds of optimization problems, which are an adaptation of the single objective case. Six versions with incremental features are presented as an evolutive path, beginning in a single colony approach, where no depth search is applied, to the final epsilon-DANTE. Versions are compared among themselves in a set of instances of the multiple objective Traveling Salesman Problem. Finally, our best version of epsilon-DANTE is compared with several established heuristics in the field showing some promising results.
  • Framework for a Hospitality Big Data Warehouse: The Implementation of an Efficient Hospitality Business Intelligence System
    Publication . Ramos, Celia; Martins, Daniel; Serra, Francisco; Lam, Roberto; Cardoso, Pedro; Correia, Marisol; Rodrigues, João
    order to increase the hotel's competitiveness, to maximize its revenue, to meliorate its online reputation and improve customer relationship, the information about the hotel's business has to be managed by adequate information systems (IS). Those IS should be capable of returning knowledge from a necessarily large quantity of information, anticipating and influencing the consumer's behaviour. One way to manage the information is to develop a Big Data Warehouse (BDW), which includes information from internal sources (e.g., Data Warehouse) and external sources (e.g., competitive set and customers' opinions). This paper presents a framework for a Hospitality Big Data Warehouse (HBDW). The framework includes a (1) Web crawler that periodically accesses targeted websites to automatically extract information from them, and a (2) data model to organize and consolidate the collected data into a HBDW. Additionally, the usefulness of this HBDW to the development of the business analytical tools is discussed, keeping in mind the implementation of the business intelligence (BI) concepts.
  • A visual programming language for soccer
    Publication . Belguinha, António; Rodrigues, Pedro; Cardoso, Pedro J. S.; Rodrigues, J. M. F.; Paciência, Domingos
    The use of Information Technologies (IT) in high competition sports is an instrument often used. However, the majority of the performers, including technical teams, do not have skills to program those IT tools to their needs. In this paper we present the low level implementation of a visual programming language (VPL) that allows the user without programming expertise to produce relatively complex programs by drawing them on a web application. The VPL tool application is illustrated by applying it to detect programmed situations from a soccer game, using previously obtained tracking data. The tool can be applied to other collective ball sports.