397 research outputs found

    Maritime Transport, Atlantic and Mediterranean Port Networks The Example of the Canary Islands

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    El transporte marítimo presenta en la actualidad un papel fundamental en las relaciones socioeconómicas a nivel mundial. Determinadas políticas como la globalización, no podrían comprenderse sin el desarrollo de la conectividad marítima y su grado de accesibilidad. El objetivo de este trabajo, además de realizar una aproximación al marco teórico y metodológico, es poner en relación el desarrollo con el transporte marítimo, y su aplicación al caso concreto de Canarias, donde analizamos su accesibilidad desde el punto de vista de la conectividad y, en particular, de los horarios y tarifas en el contexto de la propuesta del Eje Transinsular de Transportes, una política encaminada a cohesionar el territorio a través del transporte marítimo y terrestre. Se ahonda en las deficiencias de accesibilidad, discutiendo sus debilidades.Maritime transport currently plays a key role in global socio-economic relations. Certain policies, such as globalization, could not be understood without the development of maritime connectivity and its degree of accessibility. The aim of this work, in addition to making an approximation to the theoretical and methodological framework, is to relate development to maritime transport and its application to the specific case of the Canary Islands, where we analyse accessibility from the point of view of connectivity and, in particular, timetables and taxes in the context of the proposal for the Transinsular Axis of Transport, a policy aimed at cohering the territory through maritime and land transport. It delves into accessibility deficiencies, discussing their weaknesses.Ministerio de Economía y Competitividad HAR2015-64044-R HAR2016-81812-RED

    Managing QoS in a NGN using a PBM approach

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    Next Generation Network (NGN) management represents an enormous challenge due to the large number of managed elements, the variety of roles the managed entities play in the network and the difficulty of orchestrating management actions. Several NGN standardization bodies point toward Policy Based Management as the best approach for NGN network management. This paper describes a management solution for a NGN IP Multimedia Subsystem (IMS) QoS management scenario based on WBEM technology. The proposal is for a WBEM-based policy server, a graphical policy editor application and instrumentation logic for the NGN QoS Management. The graphical policy editor reduces the learning curve imposed by the policy specification language, allowing the specification of policies through a rich and user-friendly visual interface, hiding the CIM syntax complexity but keeping CIM’s potential

    Evaluation of policy based admission control mechanisms in NGN

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    The 3GPP consortium proposed in the release 7 of the IP Multimedia Subsystem (IMS) a Diameter interface for the resource admission communication process replacing the previous COPS solution. Although both academic and industry communities have deeply debate the advantages and disadvantages of each protocol, its impact in NGN may have not been thoroughly quantified. This paper compares both protocols in terms of messages exchanged between network entities, and of bandwidth requirements during the admission control process. Based on general network operator environment characteristics, we present several exploitation scenarios where it is analyzed the scalability and adequacy of each protocol

    Coherent, automatic address resolution for vehicular ad hoc networks

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    Published in: Int. J. of Ad Hoc and Ubiquitous Computing, 2017 Vol.25, No.3, pp.163 - 179. DOI: 10.1504/IJAHUC.2017.10001935The interest in vehicular communications has increased notably. In this paper, the use of the address resolution (AR) procedures is studied for vehicular ad hoc networks (VANETs). We analyse the poor performance of AR transactions in such networks and we present a new proposal called coherent, automatic address resolution (CAAR). Our approach inhibits the use of AR transactions and instead increases the usefulness of routing signalling to automatically match the IP and MAC addresses. Through extensive simulations in realistic VANET scenarios using the Estinet simulator, we compare our proposal CAAR to classical AR and to another of our proposals that enhances AR for mobile wireless networks, called AR+. In addition, we present a performance evaluation of the behaviour of CAAR, AR and AR+ with unicast traffic of a reporting service for VANETs. Results show that CAAR outperforms the other two solutions in terms of packet losses and furthermore, it does not introduce additional overhead.Postprint (published version

    Blanquitudes y devenires indígenas: Resistencias latinoamericanas a la hegemonía occidental

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    In this theoretical-interpretative writing, we use the concepts of the Ecuadorian philosopher Bolívar Echeverría "whiteness" and "baroque ethos" to relate them to the analysis of certain current indigenous movements as alternatives to the Eurocentric capitalist model typical of "western" modernity. For this, we make a brief tour of the most relevant political aspects as normative achievements of global indigenism, in order to understand them as resistance to the hegemonic model of Eurocentric modernity that supposedly universalizes a concrete way of understanding nature-culture relations; labor-capital; individual-community. In the final part, we describe certain cases from the global South, especially Guarani spirituality in the border area, as indigenous counter-hegemonies and their contribution to the realization of alternative models to understand, live and transform capitalism. As conclusions we advance towards a philosophical-anthropological reflection that serves as a critique of capitalist ethnocentrism but also of the moral relativism typical of the beginnings of the anthropological discipline.En este escrito de carácter teórico-interpretativo utilizamos los conceptos del filósofo ecuatoriano Bolívar Echeverría “blanquitud” y “ethos barroco” para relacionarlos con el análisis de ciertos movimientos indígenas actuales en tanto alternativas al modelo capitalista eurocéntrico propio de la modernidad “occidental”. Para ello realizamos un breve recorrido de los aspectos políticos más relevantes en tanto logros normativos del indigenismo global, con el fin de entenderlos como resistencias al modelo hegemónico de la modernidad eurocéntrica que pretendidamente universaliza un modo concreto de entender las relaciones naturaleza-cultura; trabajo-capital; individuo-comunidad. En la parte final describimos ciertos casos provenientes del Sur global, especialmente la espiritualidad guaraní en zona fronteriza, como contrahegemonías indígenas y su aporte a la concreción en modelos alternativos para entender, vivir y transformar el capitalismo. Como conclusiones avanzamos hacia una reflexión filosófica-antropológica que sirva de crítica al etnocentrismo capitalista pero también al relativismo moral propio de los inicios de la disciplina antropológica

    REFLECTIONS ABOUT KNOWLEDGE, CRITICISM AND ACADEMIC ANTHROPOLOGICAL KNOWLEDGE IN LATIN AMERICA

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    In this theoretical-reflexive text, the axis of knowledge and power in the world of Anthropology that falls on Latin America is raised. Its interest relies on knowing the local-global relations of the so-called peripheral academies, with the core traditions of the discipline, its vanishing points, convergences and criticisms. Special reference is made to our own academic and research experiences in Spain, Chile, Mexico and Ecuador, where the clash between what we consider knowledge and what we propose as academic axes is evident; such experiences are related to classical texts of different national anthropologies, which are interpreted under a hermeneutical vision. Through this context, we propose to what extent a postcolonial anthropology is possible in Latin America, when the reality is the urgency of a strong nationalist feeling.En este texto de carácter teórico-reflexivo, se plantea el eje del saber y el poder en el mundo de la Antropología que recae sobre América Latina. El interés del mismo radica en conocer las relaciones locales-globales de las academias denominadas periféricas, con las tradiciones centrales de la disciplina, sus puntos de fuga, convergencias y críticas. Se hace especial referencia a nuestras propias experiencias académicas e investigativas en España, Chile, México y Ecuador, donde el choque entre lo que consideramos conocimiento y lo que planteamos como ejes académicos es evidente; dichas experiencias son puestas en relación con textos clásicos de diferentes antropologías nacionales, los cuales son interpretados bajo una visión hermenéutica. En este sentido planteamos qué punto es posible una antropología de corte postcolonial en América Latina, cuando la realidad es la emergencia de un fuerte sentimiento nacionalista

    Blanquitudes y devenires indígenas

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    En este escrito de carácter teórico-interpretativo utilizamos los conceptos del filósofo ecuatoriano Bolívar Echeverría “blanquitud” y “ethos barroco” para relacionarlos con el análisis de ciertos movimientos indígenas actuales en tanto alternativas al modelo capitalista eurocéntrico propio de la modernidad “occidental”. Para ello realizamos un breve recorrido de los aspectos políticos más relevantes en tanto logros normativos del indigenismo global, con el fin de entenderlos como resistencias al modelo hegemónico de la modernidad eurocéntrica que pretendidamente universaliza un modo concreto de entender las relaciones naturaleza-cultura; trabajo-capital; individuo-comunidad. En la parte final describimos ciertos casos provenientes del Sur global, especialmente la espiritualidad guaraní en zona fronteriza, como contrahegemonías indígenas y su aporte a la concreción en modelos alternativos para entender, vivir y transformar el capitalismo. Como conclusiones avanzamos hacia una reflexión filosófica-antropológica que sirva de crítica al etnocentrismo capitalista pero también al relativismo moral propio de los inicios de la disciplina antropológica

    Fischer-Tropsch synthesis in microchannels

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    Different metallic supports (aluminum foams of 40ppi, honeycomb monolith and micromonolith of 350 and 1180cpsi, respectively) have been loaded with a 20%Co-0.5%Re/γ-Al2O3 catalyst by the washcoating method. Layers of different thicknesses have been deposited onto the metallic supports. The catalytic coatings were characterized measuring their textural properties, adhesion and morphology. These structured catalysts have been tested in the Fischer-Tropsch synthesis (FTS) and compared with a microchannel block presenting perpendicular channels for reaction and cooling. The selectivity depends on the type of support used and mainly on the thickness of the layer deposited. In general, the C5+ selectivity decreased at increasing CO conversion for all of the systems (powder, monoliths, foams and microchannels block). On the other hand, the selectivity to methane increased with the thickness of the catalytic layer due to the higher effective H2/CO ratio over the active sites resulting from the higher diffusivity of H2 compared with CO in the liquid products filling the pores. The C5+ selectivity of the microchannels reactor is higher than that of the structured supports and the powder catalyst.Ministerio de Ciencia e Innovación MAT2006-12386-C05, ENE2009-14522-C0
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