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Item Architecture and approach for obtaining spectrum availability information(2011) Matinmikko, Marja; Rauma, Tapio; Mustonen, Miia; Del Ser, Javier; IAThis paper presents a novel architecture and approach for obtaining spectrum availability information in future cognitive radio systems (CRS). CRS can opportunistically access spectrum by identifying unoccupied channels while keeping higher priority systems on the same channel free from harmful interference. Knowledge of the current state of the spectrum use is of utmost importance for CRS operations. There are different techniques for obtaining spectrum availability information including e.g. cognitive pilot channels, databases, spectrum sensing techniques, and combinations thereof. For spectrum sensing there are different algorithms and cooperative combining techniques with different characteristics and capabilities in terms of e.g. performance, complexity, and requirement of a priori information. This paper presents a unified architecture for selecting methods for obtaining spectrum availability information taking into account the operational environment and underlying policies. In addition, a novel low complexity heuristic decision making method is presented for selecting the spectrum sensing technique taking into account different capabilities and requirements while being adaptable to the changing environment.Item Decision-making system for obtaining spectrum availability information in opportunistic networks(2011) Matinmikko, Marja; Mustonen, Miia; Rauma, Tapio; Del Ser, Javier; IAOpportunistic networks with cognitive management systems can improve the resource use in future wireless communication networks by forming local clusters that are temporary extensions of the infrastructure and governed by the operator. This paper presents a decision making system that selects the techniques for obtaining spectrum availability information in opportunistic networks. The proposed decision making system selects the most suitable technique(s) from cognitive control channels, databases, and spectrum sensing techniques. Moreover, a novel and simple rule-based expert system is developed to choose the spectrum sensing technique among energy detection, correlation-based detection, and waveform-based detection. The selection is made based on the required probability of detection, operational SNR, available time, and available a priori information. The developed rule-based decision making system is presented in the form of a decision tree to illustrate the dominating paths that influence the decisions. Situations where none of the considered spectrum sensing techniques can meet the given conditions are identified and new approaches are proposed including cooperative sensing and changing of the channel. Results are presented to verify the functioning of the proposed decision making system and to show the relative frequencies of the different selected sensing techniques. Significant improvements can be obtained when the decision making system is used compared to using a single sensing technique instead.Item Intelligent, sustainable and integrated system of management of structures(International Association for Bridge and Structural Engineering (IABSE), 2019) Royes, Miquel Morata; Gil, Lívia Garcia; Caldentey, Alejandro Pérez; Vila, Javier Gimenez; Lasso, Abel Capelastegui; Navascues, Óscar Muñoz; Infraestructuras y Edificios; SMART_MONIn Spain, the national road network comprises over 17.000 bridges and viaducts, besides those managed by local and regional administrations. Many of these structures are very old; however, it was not until the 90s of the XX century that maintenance awareness rose among the society. Inspections are currently carried out visually, on a manual basis, implying low effectiveness and high costs. To tackle these issues the SISGES project was conceived and aimed at developing a smart management system capable of making rational decisions regarding the maintenance and repair of existing structures. The methodology that has been followed to achieve this goal is to study the current available technologies, develop a data management structure, develop a monitoring system for each structure, create a structural model while considering interoperability with BIM and finally, develop a management application/software to be used for both technical profile users and general managers. The SISGES platform comprises remote inspection technology, which reduces the inspection times and costs while increasing workers’ safety; continuous monitoring technologies, registering displacements, vibrations, temperature and humidity; scanning technologies to create three-dimensional models of the structures and BIM technologies to assign each element with an attribute. Overall, this makes an innovative and integrated infrastructure management system in line with available technologies and capabilities while maximizing the efficiency of inspection and monitoring for current and future bridges and viaducts.