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Faulin J.,Public University of Navarra | Lera-Lopez F.,Public University of Navarra | Juan A.A.,Open University of Catalonia
International Journal of Information Systems and Supply Chain Management | Year: 2011

The object of logistic management is to optimise the whole value chain of the distribution of goods and merchandise. One of the main aspects of such an analysis is the optimisation of vehicle routes to deliver final products to customers. There are many algorithms to optimise the related vehicle routing problem. The objective function of that problem usually involves distance, cost, number of vehicles, or profits. This study also takes safety and environmental costs into account. Thus, the authors develop variants to traditional heuristic algorithms, in which they include the traditional costs along with safety and environmental cost estimates for real scenarios in Spain. This methodology is called ASEC (Algorithms with Safety and Environmental Criteria). These considerations raise the value of the global objective function, but permit a more realistic cost estimate that includes not only the internal costs involved in the problem but also the related externalities. Finally, real cases are discussed, and solutions are offered using the new ASEC methodology. Copyright © 2011, IGI Global. Source

Fernandez-Ardevol M.,Open University of Catalonia | Ivan L.,National School of Political Studies and Public Administration
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2015

We analyze the influence of age on mobile computer anxiety in a sample of 158 individuals 55+ by means of path analysis modeling. Taking as the endogenous variable a mobile computer anxiety scale (MCAS, Wang 2007), models include demographic and socioeconomic variables and a computer experience scale – based on the familiarity and frequency of use of different information and communication technologies. Results confirm a positive influence of age on mobile computer anxiety which is mediated by both socio-economic variables and computer experience. The influence of age on mobile computer anxiety is comparatively low. Age is not the relevant dimension to explain computer anxiety, as socio-economic background and computer experience have higher explanatory capacity. This result may explain the inconsistent results regarding the direct relationship between age and computer anxiety available in the literature. © Springer International Publishing Switzerland 2015 Source

Mesodiakaki A.,Polytechnic University of Catalonia | Adelantado F.,Open University of Catalonia | Alonso L.,Polytechnic University of Catalonia
IEEE Communications Magazine | Year: 2014

Due to the ever increasing data traffic demands, which are directly connected to increased energy consumption, it becomes challenging for operators to achieve capacity enhancement while limiting their electric bill. To that end, exploiting the context awareness of future cognitive networks is expected to play a key role. Next generation cellular networks are about to include a plethora of small cells, with users being able to communicate via multiple bands. Given that small cells are expected to be eventually as close as 50 m apart, not all of them will have a direct connection to the core network; thus, multihop communication through neighboring small cells may be required. In such architectures, the user association problem becomes challenging, with backhaul energy consumption being a definitive parameter. Thus, in this article, we study the user association problem in cognitive heterogeneous networks. We evaluate the existing approaches in terms of energy efficiency and show the potential of exploiting the available context-aware information (i.e., users' measurements and requirements, knowledge of the network architecture, and the available spectrum resources of each base station) to associate the users in an energyefficient way, while maintaining high spectrum efficiency. Our study considers both the access network and backhaul energy consumption, while the performance of the association algorithms is evaluated under two different case study scenarios. © 2014 IEEE. Source

Martinez-Lopez F.J.,University of Granada | Martinez-Lopez F.J.,The Open Group | Pla-Garcia C.,Open University of Catalonia | Gazquez-Abad J.C.,University of Almeria | Rodriguez-Ardura I.,Applied Technology Internet
Electronic Commerce Research and Applications | Year: 2014

To date, the utilitarian benefits of online consumption have only been partially investigated. This study undertakes an exhaustive approach to fully delimit the dimensional structure related to the utilitarian motivations for online consumption. First, an in-depth literature review is carried out, in order to allow the proposal of an aprioristic base structure of eleven categories of utilitarian motivations. Next, qualitative analyses (focus groups and personal interviews) are applied to assess and eventually refine the structure of utilitarian motivations proposed after the literature review, their labels and respective measurement scales. Finally, this qualitative phase concludes with ten motivational categories and 46 items. Then, quantitative analyses (exploratory and detailed confirmatory factor analyses) are applied, based on a questionnaire administered to a sample of 667 Internet users, to keep refining and to eventually validate both the dimensional structure of motivations and the related measurement scales. Finally, a structure of 9 utilitarian motivations (and corresponding set of 36 items) is established, with the following labels: assortment, economy, convenience, availability of information, adaptability/customization, desire for control, payment services, anonymity, and absence of social interaction. The nomological validity of this structure is satisfactorily tested using a second-order factor model. The article finishes by discussing some implications for practitioners. © 2014 Elsevier B.V. All rights reserved. Source

Izard O.M.,Open University of Catalonia
Proceedings of the IADIS International Conference Web Based Communities and Social Media 2013, Proceedings of the IADIS International Conference Collaborative Technologies 2013 | Year: 2013

This research proposes a model to test the influence of special factors that have been found as critical for the acceptance and use of social networking sites for knowledge exchange adjusting it to different technology adoption theories. The key factors of the model are based on the perception of users of their autonomy, the openness of the sites, the diversity of the members of the networks and the interactivity. We have tested the model with case study of virtual communities of professionals and we used the SEM (Structural Equation Modeling) analysis. The results certify the validity of the model affording a better understanding on the relations between the different factors and how they influence the user's behavior of the social networking sites. © 2013 IADIS. Source

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