Joaquín Sánchez-Soriano

Road traffic congestion detection through cooperative Vehicle-to-Vehicle communications

Cooperative vehicular systems are being developed to improve traffic safety and management. Reducing road traffic congestion can be achieved through effective management strategies. In this sense, mechanisms for its rapid and accurate detection that allow evaluating the road network performance are crucial. Current Intelligent Transportation Systems (ITS) require the deployment of infrastructure sensors to monitor traffic conditions. Their installation is often expensive and their capability to provide accurate traffic information is limited. In this context, this paper proposes CoTEC (COperative Traffic congestion detECtion), a novel cooperative technique based on Vehicle-to-Vehicle (V2V) communications and fuzzy logic to detect road traffic congestion without the need to deploy infrastructure sensors. The proposed technique is also capable to accurately detect the traffic congestion intensity and length.

Game Theory Techniques for University Management: An Extended Bankruptcy Model

In this paper we analyze a conflict situation in university management. This situation deals with how to allocate money among faculties to buy equipment for teaching laboratories. We will tackle this real problem using tools from Game Theory. We discuss the proposal which has been implemented in the Miguel Hernández University. Related to this kind of situation we introduce an extended bankruptcy problem, in which two ways of measuring the demands of the administrative entities exist: the “objective entitlements” and the “claims”. We study and propose suitable bankruptcy rules for this new type of problem.

Analysis of the Evolution of the Inland Traffic Distribution and Provincial Hinterland Share of the Spanish Port System

Abstract This paper proposes a methodology based on non‐parametric statistical techniques to analyse whether the ordinal preferences in the port selection process are stable, and also the intensity of those preferences. We apply this methodology to the Spanish case from the landside perspective in order to answer the following question: Has the increase in inter‐port competition changed the port preferences? The result obtained is that the port selection pattern of the provinces has changed slightly, leading us to the conclusion that the relative appeal of the ports remains quite stable from the spatial perspective, despite the reform of the port system.

On the core, the Weber set and convexity in games with a priori unions

This paper deals with the concepts of core and Weber set with a priori unions a la Owen. As far as we know, the Owen approach to games with a priori unions has never been studied from the coalitional stability point of view. Thus we introduce the coalitional core and coalitional Weber set and characterize the class of convex games with a priori unions by means of the relationships between both solution concepts.

Empirical performance models for P2P and two hops multi-hop cellular networks with mobile relays

Multi-hop Cellular Networks using Mobile Relays (MCN-MR) are being studied to overcome certain limitations of traditional single hop cellular systems through the integration of cellular and Peer to Peer (P2P) ad-hoc communications. Current MCN-MR research is generally analytical or simulation based, and there is yet the need for studies that empirically demonstrate the potential of MCN-MR and provide valuable models for the research community. In this context, this paper presents the first 2-hop MCN-MR empirical performance models derived from field tests over live networks. The MCN-MR performance is measured for downlink transmissions as the throughput experienced by mobile users. The model parameters are shown to depend on the distance, Line-Of-Sight (LOS) or Non-LOS (NLOS) conditions, and communication settings of the ad-hoc link. As a result, the paper also reports a set of distance-based empirical P2P link level models.

Joint radio resource management for heterogeneous wireless systems

Heterogeneous wireless systems are characterized by the physical coexistence of a variety of radio access technologies with different, but also complementary, technical characteristics and performance. A key aspect of heterogeneous systems is then the implementation of efficient joint radio resource management mechanisms. In this context, this paper presents and evaluates novel joint radio resource management techniques based on the CEA bankruptcy distribution rule. The proposed policies base their distribution decisions on the system conditions and the varying quality of service requirements present in multimedia scenarios. The obtained results demonstrate that the proposed policies can efficiently distribute the radio resources with a low computational cost.

Bankruptcy-based radio resource management for multimedia mobile networks

The transmission of bandwidth-demanding multimedia applications in capacity-constrained mobile radio networks requires optimizing the usage and assignment of radio resources following the varying quality of service requirement characteristics of multimedia traffic environments. Considering the capacity of the bankruptcy theory to deal with situations where the demand for resources is higher than its availability, this work proposes the application of bankruptcy theories to design efficient radio resource management policies that provide the highest possible quality of service levels while guaranteeing user fairness. Copyright

Integer linear programming optimization of joint RRM policies for heterogeneous wireless systems

Wireless systems will be characterized by the coexistence of heterogeneous Radio Access Technologies (RATs) with different, but also complementary, performance and technical characteristics. These heterogeneous wireless networks will provide network operators the possibility to efficiently and coordinately use the heterogeneous radio resources, for which novel Joint Radio Resource Management (JRRM) policies need to be designed. In this context, this work proposes and evaluates a JRRM policy that simultaneously determines for each user an adequate combination of RAT and number of radio resources within such RAT to guarantee the user/service QoS requirements, and efficiently distribute the radio resources considering a user fairness approach aimed at maximizing the system capacity. To this aim, the JRRM algorithm, which takes into account the discrete nature of radio resources, is based on integer linear programming optimization mechanisms.

Design and implementation of a decision support system for competitive electricity markets

In this paper we describe software which could be used as a decision support tool for decision makers in competitive electricity markets. The tool is based on the behavior of the competitors in the market, thus many different parameters around them are considered and, additionally, many different scenarios can be used. The possible results are obtained by simulation. Two modes are implemented; one to simulate the functioning of a competitive electricity market and the other, called manual, to evaluate the success of particular strategies by a user. Finally, some computational experience is reported to validate the simulation model.

Pairwise solutions and the core of transportation situations

The main aim of this paper is to study the relationship between the so-called pairwise solutions and the core of transportation situations (or games). With this objective in mind, we show that every core element of a transportation situation is contained in a pairwise solution with a specific weight system. Therefore every core element is, in fact, a particular pairwise distribution. Furthermore, given a core element, we outline a procedure in three steps to obtain the corresponding pairwise distribution with weight system.