Change and Contradiction: A Criticism of the Hegelian Account of Motion

In his In Contradiction (1987), Priest levelled three powerful arguments against the received Russellian view of change and motion. He argued that his preferred paraconsistent theory of change, the Hegelian account, is immune from these objections. Here I argue that these three arguments are sound, but that the Hegelian account falls pray to them too. I conclude, however, that the Hegelian account is in a better position to tackle these challenges

3D magnetic configuration of the Halpha filament and X-ray sigmoid in NOAA AR 8151

We investigate the structure and relationship of an H $\alpha$ filament and an X-ray sigmoid observed in active region NOAA 8151. We first examine the presence of such structures in the reconstructed 3D coronal magnetic field obtained from the non-constant- $\alpha$ force-free field hypothesis using a photospheric vector magnetogram (IVM, Mees Solar Observatory). This method allows us to identify several flux systems: a filament (height 30 Mm, aligned with the polarity inversion line (PIL), magnetic field strength at the apex 49 G, number of turns 0.5-0.6), a sigmoid (height 45 Mm, aligned with the PIL, magnetic field strength at the apex 56 G, number of turns 0.5-0.6) and a highly twisted flux tube (height 60 Mm, magnetic field strength at the apex 36 G, number of turns 1.1-1.2). By searching for magnetic dips in the configuration, we identify a filament structure which is in good agreement with the H $\alpha$ observations. We find that both filament and sigmoidal structures can be described by a long twisted flux tube with a number of turns less than 1 which means that these structures are stable against kinking. The filament and the sigmoid have similar absolute values of $\alpha$ and Jz in the photosphere. However, the electric current density is positive in the filament and negative in the sigmoid: the filament is right-handed whereas the sigmoid is left-handed. This fact can explain the discrepancies between the handedness of magnetic clouds (twisted flux tubes ejected from the Sun) and the handedness of their solar progenitors (twisted flux bundles in the low corona). The mechanism of eruption in AR 8151 is more likely not related to the development of instability in the filament and/or the sigmoid but is associated with the existence of the highly twisted flux tube (~1.1-1.2 turns)

A Dynamic Clustering and Resource Allocation Algorithm for Downlink CoMP Systems with Multiple Antenna UEs

Coordinated multi-point (CoMP) schemes have been widely studied in the recent years to tackle the inter-cell interference. In practice, latency and throughput constraints on the backhaul allow the organization of only small clusters of base stations (BSs) where joint processing (JP) can be implemented. In this work we focus on downlink CoMP-JP with multiple antenna user equipments (UEs) and propose a novel dynamic clustering algorithm. The additional degrees of freedom at the UE can be used to suppress the residual interference by using an interference rejection combiner (IRC) and allow a multistream transmission. In our proposal we first define a set of candidate clusters depending on long-term channel conditions. Then, in each time block, we develop a resource allocation scheme by jointly optimizing transmitter and receiver where: a) within each candidate cluster a weighted sum rate is estimated and then b) a set of clusters is scheduled in order to maximize the system weighted sum rate. Numerical results show that much higher rates are achieved when UEs are equipped with multiple antennas. Moreover, as this performance improvement is mainly due to the IRC, the gain achieved by the proposed approach with respect to the non-cooperative scheme decreases by increasing the number of UE antennas.Comment: 27 pages, 8 figure

Downlink and Uplink Decoupling: a Disruptive Architectural Design for 5G Networks

Cell association in cellular networks has traditionally been based on the downlink received signal power only, despite the fact that up and downlink transmission powers and interference levels differed significantly. This approach was adequate in homogeneous networks with macro base stations all having similar transmission power levels. However, with the growth of heterogeneous networks where there is a big disparity in the transmit power of the different base station types, this approach is highly inefficient. In this paper, we study the notion of Downlink and Uplink Decoupling (DUDe) where the downlink cell association is based on the downlink received power while the uplink is based on the pathloss. We present the motivation and assess the gains of this 5G design approach with simulations that are based on Vodafone's LTE field trial network in a dense urban area, employing a high resolution ray-tracing pathloss prediction and realistic traffic maps based on live network measurements.Comment: 6 pages, 7 figures, conference paper, submitted to IEEE GLOBECOM 201

Soft Cache Hits and the Impact of Alternative Content Recommendations on Mobile Edge Caching

Caching popular content at the edge of future mobile networks has been widely considered in order to alleviate the impact of the data tsunami on both the access and backhaul networks. A number of interesting techniques have been proposed, including femto-caching and "delayed" or opportunistic cache access. Nevertheless, the majority of these approaches suffer from the rather limited storage capacity of the edge caches, compared to the tremendous and rapidly increasing size of the Internet content catalog. We propose to depart from the assumption of hard cache misses, common in most existing works, and consider "soft" cache misses, where if the original content is not available, an alternative content that is locally cached can be recommended. Given that Internet content consumption is increasingly entertainment-oriented, we believe that a related content could often lead to complete or at least partial user satisfaction, without the need to retrieve the original content over expensive links. In this paper, we formulate the problem of optimal edge caching with soft cache hits, in the context of delayed access, and analyze the expected gains. We then show using synthetic and real datasets of related video contents that promising caching gains could be achieved in practice

Las pedagogías de la sexualidad en el mercado de formación docente : Un análisis de dos propuestas de alcance masivo en el campo educativo cordobés

El presente trabajo analiza las dos experiencias de mayor alcance vinculadas al campo de la formación docente que tuvieron lugar en la provincia de Córdoba en el marco inaugurado por la sanción de la ley nacional de educación sexual. Se trata de dos dispositivos de carácter heterogéneo que comparten, sin embargo, su finalidad explícita. Esto es, ofrecer una respuesta ante la insistencia de una demanda que se acababa de instalar en el campo educativo por la sanción de la ley de educación sexual. En este sentido, ambos dispositivos emergen en el mercado del discurso social presentándose con la forma de una respuesta a una pregunta que se repite: “y ahora ¿qué vamos a hacer?”. Uno de los dispositivos es un curso de formación docente desarrollado bajo la modalidad a distancia cuyos fascículos fueron distribuidos por el periódico de mayor tirada de la provincia, La Voz del Interior. El otro dispositivo es un libro escrito por una psicopedagoga conocida en el ámbito educativo provincial que goza de cierta presencia en los masivos de comunicación. (Párrafo extraído del texto a modo de resumen)Eje temático 9: Educación y géneroFacultad de Humanidades y Ciencias de la Educació

Towards an EU asylum policy : "Protection" for whom?

This thesis focuses on the gradual development of EU asylum co-operation over the last fifteen years, following a historical/evolutionary approach that concentrates on two main aspects. On the one hand, this work attempts to explain the reasons for the rise since 1985 of a common interest among EU Member States in co-ordinating their national asylum policies. It also attempts to assess whether such asylum coordination has been characterised by an identifiable pattern of evolution, for instance in the choice of priorities or of an overall strategy, and to ascertain whether these initial efforts have finally developed into a fully fledged EU asylum policy. On the other hand, this research has concentrated on the impact of these initiatives on the levels of refugee protection in the EU and in particular on whether they have been compatible with previous international refugee and Human Rights obligations. This work also suggests ways in which enhanced levels of refugee protection could be integrated into the development of an efficient EU asylum policy This research begins by outlining the international foundations of refugee protection, such as the 1951 Geneva Convention and the UNHCR and the way they have evolved in the last four decades. It then analyses the initial attempts of EC countries to co-ordinate their asylum measures through the burgeoning European Political Co-operation. The role played by parallel asylum initiatives taken by a smaller number of EC Members within the Schengen framework is also highlighted. This thesis then focuses on the subsequent Maastricht Treaty and the nature of the Third Pillar provisions on asylum, the operating structures set up for asylum coordination and the resulting interaction patterns between Member States and the Union's Institutions. It also assesses the EU initiatives that were undertaken within the Third Pillar framework and the particular problems that they presented. This research then continues by analysing in detail the new complex asylum framework that emerged in 1997 with the Amsterdam Treaty. The roles played by the subsequent Tampere European Council and the recent Nice Treaty are also explored as they have provided both a development path and a fine- tuning of decision-making processes of the new EU asylum co-operation. Finally, attention is given to the possible impact that the EU Charter of Fundamental Rights, approved at Nice, might have on strengthening the Human Rights dimension of asylum in future EU action

Understanding Noise and Interference Regimes in 5G Millimeter-Wave Cellular Networks

With the severe spectrum shortage in conventional cellular bands, millimeter-wave (mmWave) frequencies have been attracting growing attention for next-generation micro- and picocellular wireless networks. A fundamental and open question is whether mmWave cellular networks are likely to be noise- or interference-limited. Identifying in which regime a network is operating is critical for the design of MAC and physical-layer procedures and to provide insights on how transmissions across cells should be coordinated to cope with interference. This work uses the latest measurement-based statistical channel models to accurately assess the Interference-to-Noise Ratio (INR) in a wide range of deployment scenarios. In addition to cell density, we also study antenna array size and antenna patterns, whose effects are critical in the mmWave regime. The channel models also account for blockage, line-of-sight and non-line-of-sight regimes as well as local scattering, that significantly affect the level of spatial isolation