Structural aspects of the non-uniformly continuous functions and the unbounded functions within C(X)

We prove in this paper that if a metric space supports a real continuous function which is not uniformly continuous then, under appropriate mild assumptions, there exists in fact a plethora of such functions, in both topological and algebraical senses. Corresponding results are also obtained concerning unbounded continuous functions on a non-compact metrizable space.Plan Andaluz de Investigación (Junta de Andalucía)Ministerio de Economía y Competitividad (MINECO). Españ

Aproximación a los comportamientos técnicos de los neandertales, a través del estudio de los conjuntos líticos adscritos al Paleolítico Medio en Gibraltar

This work presents the technological study of the lithic assemblages associate to the Middle Palaeolithic sites from Gibraltar: Devil’s Tower, Ibex Cave, Vanguard Cave, Gorham’s Cave,Beefsteak and Europe I. The  results  show  a  technical  variability  in  each  site  and  at  the same  time  a  technological continuity in Gibraltar since the MIS 5 to 3.Este trabajo presenta el estudio tecnológico de los conjuntos líticos de los yacimientos adscritos al Paleolítico Medio de Gibraltar: Devil ́s Tower, Ibex Cave, Vanguard Cave, Gorham ́s Cave, Beefsteak y Europe I. Los resultados nos muestran una variabilidad técnica en cada uno de los yacimientos y a su vez una continuidad tecnológica en Gibraltar desde el MIS 5 al 3

Oil price and economic growth : a long story?

Este trabajo analiza los cambios en la relación entre el precio del petróleo y el PIB de Estados Unidos desde una perspectiva de largo plazo. Aunque en ninguna de las dos series (tasas de crecimiento del PIB y del precio del petróleo) se detectan cambios estructurales en la media, se identifican diferentes períodos de volatilidad en cada una de ellas por separado. Adoptando un enfoque multivariante, no se observa un efecto significativo entre los cambios en el precio del petróleo y el crecimiento del PIB cuando se considera el período completo. Sin embargo, a través de un análisis rolling y aplicando un test para la detección de cambios estructurales en un marco multivariante, se identifica una relación significativa entre ambas variables en algunos subperíodos. Por último, se obtiene evidencia, por medio de un modelo VAR time-varying, de que el impacto de los shocks en el precio del petróleo sobre el crecimiento del PIB ha disminuido a lo largo del tiempo. Asimismo, se observa que el efecto negativo sobre el PIB es mayor cuando se producen fuertes incrementos en el precio del petróleo, lo que apoya la evidencia empírica previa de no linealidad en la relación entre ambas variablesThis study investigates changes in the relationship between oil prices and the US economy from a long-term perspective. Although neither of the two series (oil price and GDP growth rates) presents structural breaks in mean, we identify different volatility periods in both of them, separately. From a multivariate perspective, we do not observe a significant effect between changes in oil prices and GDP growth when considering the full period. However, we find a signifi cant relationship in some subperiods by carrying out a rolling analysis and by investigating the presence of structural breaks in the multivariate framework. Finally, we obtain evidence, by means of a time-varying VAR, that the impact of the oil price shock on GDP growth has declined over time. We also observe that the negative effect is greater at the time of large oil price increases, supporting previous evidence of nonlinearity in the relationshi

Securing vehicular IPv6 communications

A common practice is applying security after a network has been designed or developed. We have the opportunity of not committing this error in vehicular networks. Apart from particular works in the literature, ETSI TC ITS has defined general security services for (vehicular) cooperative systems. However, existent efforts do not pay the needed attention to the integration of IPv6 yet. The potential of IPv6 in the field is being described within ISO TC 204, above all, but further work is needed for a proper integration of security. This work follows this direction, and a reference vehicular communication architecture considering ETSI/ISO regulations, uses Internet Protocol security (IPsec) and Internet Key Exchange version 2 (IKEv2) to secure IPv6 Network Mobility (NEMO). A key advance is also the implementation and experimental evaluation of the proposal in a challenging vertical handover scenario between 3G and 802.11p. The performance of the secured NEMO channel is widely analyzed in terms of the movement speed, bandwidth, traffic type or signal quality, and it is concluded that the addition of IPv6 security only implies a slight reduction in the overall performance, with the great advantage of providing confidentiality, integrity and authenticity to the communication path.This work has been sponsored by the EU 7th Framework Program through the ITSSv6, FOTsis, GEN6 and Inter-Trust projects (contracts 270519, 270447, 297239 and 317731), and the Ministry of Science and Innovation through the Walkie-Talkie project (TIN2011-27543-C03)

Combining user preferences and expert opinions: a criteria synergy-based model for decision making on the Web

Customers strongly base their e-commerce decisions on the opinions of others by checking reviews and ratings provided by other users. These assessments are overall opinions about the product or service, and it is not possible to establish why they perceive it as good or bad. To understand this “why”, it is necessary an expert’s analysis concerning the relevant factors of the product or service. Frequently, these two visions are not coincident and the best product for experts may not be the best one for users. For this reason, trustworthy decision-making methods that integrate the mentioned views are highly desirable. This article proposes a multi-criteria decision analysis model based on the integration of users’ preferences and experts’ opinions. It combines the majority’s opinion and criteria synergy to provide a unified perspective in order to support consumers’ ranking-based decisions in social media environments. At the same time, the model supplies useful information for managers about strengths and weaknesses of their product or service according to users’ experience and experts’ judgment. The aggregation processes and synergy criteria are modeled in order to obtain an adequate consensus mechanism. Finally, in order to test the proposed model, several simulations using hotel valuations are performed.Project UTN4058 of National Technological University (Argentine) Fellowship for Short Term Postdoctoral Stays at University of Malaga – International Campus of Excellence Andalucía Tec

Durability parameters of reinforced recycled aggregate concrete: Case study

Recycled concrete aggregate (RA) from pavement demolition was used to make concrete. Ten concrete mixtures with different replacement percentages of RA (coarse and fine) were made. The corrosion rate of steel and the electrical resistivity of concrete were determined on reinforced concrete specimens subjected to wetting-drying cycles (3.5% solution of NaCl). Corrosion rate was determined using the electrochemical technique of linear polarization resistance, while the electrical resistivity was measured by electrochemical impedance spectroscopy. The results show that the use of RA introduces more interfaces in concrete, which accelerates the steel corrosion process because the porosity increases and the electrical resistivity decreases. However, steel corrosion and the electrical resistivity in concrete are not significantly influenced by replacing a maximum 30% of coarse aggregate or 20% of fine aggregate with RA.Peer ReviewedPreprin

Enabling Process Mining in Aircraft Manufactures: Extracting Event Logs and Discovering Processes from Complex Data

Process mining is employed by organizations to completely understand and improve their processes and to detect possible deviations from expected behavior. Process discovery uses event logs as input data, which describe the times of the actions that occur the traces. Currently, Internet-of-Things environments generate massive distributed and not always structured data, which brings about new complex scenarios since data must first be transformed in order to be handled by process min ing tools. This paper shows the success case of application of a solution that permits the transformation of complex semi-structured data of an assembly-aircraft process in order to create event logs that can be man aged by the process mining paradigm. A Domain-Specific Language and a prototype have been implemented to facilitate the extraction of data into the unified traces of an event log. The implementation performed has been applied within a project in the aeronautic industry, and promis ing results have been obtained of the log extraction for the discovery of processes and the resulting improvement of the assembly-aircraft process.Ministerio de Ciencia y Tecnología RTI2018-094283-B-C3

Enforcing Behavioral Profiles through Software-Defined Networks in the Industrial Internet of Things

The fourth industrial revolution is being mainly driven by the integration of Internet of Things (IoT) technologies to support the development lifecycle of systems and products. Despite the well-known advantages for the industry, an increasingly pervasive industrial ecosystem could make such devices an attractive target for potential attackers. Recently, the Manufacturer Usage Description (MUD) standard enables manufacturers to specify the intended use of their devices, thereby restricting the attack surface of a certain system. In this direction, we propose a mechanism to manage securely the obtaining and enforcement of MUD policies through the use of a Software-Defined Network (SDN) architecture. We analyze the applicability and advantages of the use of MUD in industrial environments based on our proposed solution, and provide an exhaustive performance evaluation of the required processes

Probabilistic Seismic Vulnerability and Loss Assessment of the Buildings in Mexico City

This article presents a seismic vulnerability and risk assessment of buildings in Mexico City. A probabilistic seismic hazard analysis (PSHA) was carried out, which allowed the definition of seismic hazard curves as well as uniform hazard spectra (UHS) for several seismic zones. The seismic hazard includes the effects of all seismic sources located in an influence area with a radius of 500 km. Attenuation relationships were selected with basis in attenuation models of events affecting the areas of Central Mexico and were complemented by our own functions that include local soil effects. Already established the sources and attenuation functions, the seismic hazard is quantified throughout UHS, which calculated using a return period Tr = 100 years. For the vulnerability assessment, fragility curves were defined. Two groups of fragility curves were studied, the first for the first for buildings built before 1985, and the second for buildings built after 1985. In the first case, static nonlinear analyzes of selected buildings were performed to define the capacity spectra. In the second case, the capacity spectra were defined from design spectra of the Mexico City Building Code. The results showed a very good correlation with the seismic demands of the 2017 earthquake