Community sharing of spare network capacity Dimogerontakis, Emmanouil; Meseguer Pallarès, Roc; Navarro Moldes, Leandro; Ochoa, Sergio; Veiga, Luis In several community scenarios, people share benevolently their spare broadband Internet access connectivity with other people who cannot afford it. Although laudable, this sharing process can negatively affect the service received by the primary users, thus jeopardizing the continuity of this community service. In this paper we propose the use of a gateway that separates the traffic of the primary users from that of the secondary users, the beneficiaries of this sharing. We analyze the impact and behavior of several mechanisms for using this gateway, to determine how to maximize network utilization, use of the excess network capacity, and minimize the impact on the primary traffic. As a result we present a set of lessons learned and recommendations. Particularly, some strategies that use tunneling for managing the primary and secondary traffic achieve the best performance isolation for the primary user, while the secondary user obtains the spare capacity equivalent to non-differentiated best effort, with a limited penalty (around 20%). Combined with complementary queueing techniques (instead of FIFO), other important flows for the user experience (such as DNS or ICMP) can be practically unaffected.
Client-side routing-agnostic gateway selection for heterogeneous wireless mesh networks Dimogerontakis, Emmanouil; Neto, João; Meseguer Pallarès, Roc; Navarro Moldes, Leandro; Veiga, Luis Citizens develop Wireless Mesh Networks (WMN) in many areas as an alternative or their only way for local interconnection and access to the Internet. This access is often achieved through the use of several shared web proxy gateways. These network infrastructures consist of heterogeneous technologies and combine diverse routing protocols. Network-aware state-of-art proxy selection schemes for WMNs do not work in this heterogeneous environment. We developed a client-side gateway selection mechanism that optimizes the client-gateway selection, agnostic to underlying infrastructure and protocols, requiring no modification of proxies nor the underlying network. The choice is sensitive to network congestion and proxy load, without requiring a minimum number of participating nodes. Extended Vivaldi network coordinates are used to estimate client-proxy network performance. The load of each proxy is estimated passively by collecting the Time-to-First-Byte of HTTP requests, and shared across clients. Our proposal was evaluated experimentally with clients and proxies deployed in guifi.net, the largest community wireless network in the world. Our selection mechanism avoids proxies with heavy load and slow internal network paths, with overhead linear to the number of clients and proxies.
Les vies del morrot: El moll de San Bertrán, Barcelona. Marti Elias, Joan Qualificació obtinguda: 9
Continuing professional education for engineering faculty: transversal integration of Sustainable Human Development in basic engineering sciences courses
Continuing professional education for engineering faculty: transversal integration of Sustainable Human Development in basic engineering sciences courses Pérez Foguet, Agustí; Lazzarini, Boris The integration of sustainable development in higher education is increasingly recognised as a priority for a growing number of universities, nonetheless, barriers for change remain and particular attention should be given to the success factors fostering an effective integration. The present contribution analyses the extent to which a professional development programme, aimed at engaging and empowering faculty, has positive effects to integrate sustainable human development principles into existing courses of engineering. Specifically, the research focuses on the effects of the integration of sustainable human development in new teaching modules in a subject of basic engineering science, implemented in regular courses of the first year of the degree in engineering. The methodology includes i) a standardised test to assess sustainability literacy of the students; ii) a focus group conducted with the students of the engineering courses involved in the initiative; and iii) an in-deep interview conducted with the academic coordinator of the subject analysed. The results of the present case study highlight the relevance of professional development programmes addressed to academics with regard to the integration of sustainability principles specifically in formal science disciplines. The conclusions highlight relevant insights from the case study that are useful for supporting further integration of sustainable development in engineering disciplines.
Construction and application of Bayesian networks to support decision-making in the water, sanitation and hygiene sector: a case study of SIASAR initiative in Central America
Construction and application of Bayesian networks to support decision-making in the water, sanitation and hygiene sector: a case study of SIASAR initiative in Central America Pérez Foguet, Agustí; Requejo Castro, David; Giné Garriga, Ricard; Martínez Crespo, Gonzalo; Rodríguez Serrano, Antonio The 2030 Agenda includes a dedicated goal on water and sanitation (SDG 6) that sets out to “ensure availability and sustainable management of water and sanitation for all”. SDG 6 expands the MDG focus on drinking water and sanitation to cover the entire water cycle. A clear lesson from the MDGs is that we cannot manage what we do not measure, and there is little doubt about the role of monitoring and evaluation data in providing the evidence base for decision-making. Against this background, a number of composite indicator frameworks have been implemented to make water and sanitation quality services available and accessible to all, particularly to those most in need. Despite their significance in sector monitoring, indicators are not completely adequate to provide an insight into the complex cause and effect relations within water, sanitation and hygiene (WaSH) issues. The flexibility of Bayesian Networks (Bns) have been exploited to integrate multiple and simultaneous cause-effect or dependence relationships and unravel the linkages between poverty and WaSH services. In consequence, Bns have proved to be effective in project planning and monitoring support. Three major weaknesses however hinder a wider use of this monitoring approach in sector planning: i) an increased data demand, ii) software availability to run the networks, and iii) lack of a systematic methodology to deal with networks generation. In this study, open-databases are exploited and free software “R” is applied. One monitoring initiative is selected as initial case study due to its increasing relevance in Latin America in monitoring the WaSH sector: the Rural Water Supply and Sanitation Information System (SIASAR). On the basis of SIASAR’s conceptual framework, a simple Bn model has been applied to reflect the main issues that determine access to WaSH services. Data from Nicaragua is processed and analysed, since the Government has already carried out and completed a national baseline. The paper discusses about i) the proposed methodology to construct the networks, and ii) the potentiality of BNs in terms of evaluation and planning. It concludes that the proposed methodology represents a contribution to facilitate the use of this tool and that Bns are able to accommodate the complexities of WaSH-related issues. Additionally, they emerge as an effective management tool to support decision-makers in formulating and making informed choices between alternative actions.
Periodic points of a Landen transformation Gasull Embid, Armengol; Llorens, Mireia; Mañosa Fernández, Víctor We prove the existence of 3-periodic orbits in a dynamical system associated to a Landen transformation previously studied by Boros, Chamberland and Moll, disproving a conjecture on the dynamics of this planar map introduced by the latter author. To this end we present a systematic methodology to determine and locate analytically isolated periodic points of algebraic maps. This approach can be useful to study other discrete dynamical systems with algebraic nature. Complementary results on the dynamics of the map associated with the Landen transformation are also presented. Preprint
Analysis of the optimum gain of a high-pass l-matching network for rectennas Gasulla Forner, Manuel; Jordana Barnils, José; Sánchez Robert, Francesc Josep; Berenguer Sau, Jordi Rectennas, which mainly consist of an antenna, matching network, and rectifier, are used to harvest radiofrequency energy in order to power tiny sensor nodes, e.g., the nodes of the Internet of Things. This paper demonstrates for the first time, the existence of an optimum voltage gain for high-pass L-matching networks used in rectennas by deriving an analytical expression. The optimum gain is that which leads to maximum power efficiency of the rectenna. Here, apart from the L-matching network, a Schottky single-diode rectifier was used for the rectenna, which was optimized at 868 MHz for a power range from -30 dBm to -10 dBm. As the theoretical expression depends on parameters not very well-known a priori, an accurate search of the optimum gain for each power level was performed via simulations. Experimental results show remarkable power efficiencies ranging from 16% at -30 dBm to 55% at -10 dBm, which are for almost all the tested power levels the highest published in the literature for similar designs.
Polypropylene-based porous membranes: influence of polymer composition, extrusion draw ratio and uniaxial strain
Polypropylene-based porous membranes: influence of polymer composition, extrusion draw ratio and uniaxial strain Castejon Galan, Maria Del Pilar; Habibi, Kian; Saffar, Amir; Ajji, Abdellah; Martínez Benasat, Antonio; Arencón Osuna, David Several commercial grades of homo-polymer and its blends were selected to prepare microporous membranes through melt extrusion-annealing-uniaxial stretching technique (MEAUS). Branched or very fluid polypropylene was employed to modify the polymeric composition. In some blends, micro-sized calcium carbonate was added. We analysed the influence of sample composition, extrusion draw ratio, and we performed a deep study concerning the uniaxial strain rate, using in some cases extreme strain rates and strain extents. The crystalline features were studied by Differential Scanning Calorimetry (DSC), and the morphology of porous structure was analysed through Scanning Electron Microscopy (SEM). Thermal stability and thermomechanical performance was measured by thermogravimetric analysis (TGA) and dynamic-mechanical-thermal (DTMA) study. A close relationship was found between crystalline characteristics, porous morphology and the trends registered for permeability
Tunable substrate integrated waveguide resonators Mira, Fermin; Mateu Mateu, Jordi; Collado Gómez, Juan Carlos This paper presents a novel approach for providing SIW tunable resonators by means of placing an additional metalized via-hole on the waveguide cavity. The via-hole contains an open-loop slot on the top metallic wall. The dimensions, position and orientation of the open-loop slot defines the tuning range. Fabrication of some designs reveal good agreement between simulation and measurements. Additionally a preliminary prototype which sets the open-loop slot orientation manually is also presented, achieving the expected continuous tuning range of at least 8%. Canvi de títol a la versió final publicada per l'editor: "Mechanical tuning of substrate integrated waveguide resonators". ©2012 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.
Cooperative work and continuous assessment in an electronic systems laboratory course in a telecommunication engineering degree
Cooperative work and continuous assessment in an electronic systems laboratory course in a telecommunication engineering degree Jordana Barnils, José; Sánchez Robert, Francesc Josep
Homotopy linear algebra Gálvez Carrillo, Maria Immaculada; Kock, Joachim; Tonks, Andrew By homotopy linear algebra we mean the study of linear functors between slices of the 8-category of 8-groupoids, subject to certain finiteness conditions. After some standard definitions and results, we assemble said slices into 8-categories to model the duality between vector spaces and profinite-dimensional vector spaces, and set up a global notion of homotopy cardinality à la Baez, Hoffnung and Walker compatible with this duality. We needed these results to support our work on incidence algebras and Möbius inversion over 8-groupoids; we hope that they can also be of independent interest.
Energetical evaluation of installed absorpotion chiller systems in a field test Castro Valls, Pau Absorption chiller cooling is a recent technology based on a source of heat coming from hot water as driving energy. This hot water can come from renewable sources such as solar heating or from district heating networks as a by-product of combined heat and power plants (CHP). This technology reduces notably the electrical consumption in comparison with traditional compression cooling technologies. These benefits usually have their counterpart, which is a larger investment. This thesis describes some of the test sites that TU Berlin is currently operating in Germany and Jordan and describes some of the advanced control strategies that have been designed to regulate the operation of certain components of the system. Further in this work, specific values of system components consumption are analysed in order to explain the behaviour of the system under different operation conditions when some strategies are active or not. The thesis shows that when advanced control strategies are active in the sites and no abnormal operation conditions are given, the specific electrical consumption of the components involved in the strategies is significantly reduced, helping the absorption cooling plant to be more energy efficient.
Planificació de la xarxa de transport públic en superficie a Palma de Mallorca. Disseny i operació Pacheco Perelló, Laura El treball té com a objectiu determinar l'esquema òptim de la xarxa de transport públic en superficie a Palma de Mallorca, identificant el recorregut de cada línia i els recursos necessaris per operar-la. Així mateix, es quantificarà les prestacions i nivell de servei a l'usuari del global de la xarxa i els costos totals d'operació. Per altra banda, s'identificarà un conjunt de models d'operació a aplicar en les línies per asegurar que s'arriba a una velocitat de creuer desitjable.
Towards a post-occupancy methodology for measuring conviviality in the public realm Beltrán Rodríguez, María; Simon, Madlen Conviviality is a term which is used widely in sociology (Ivan Illich 2002, Deegan 1989, Bonnett 2010, Flanagan 2010), but not as much in urban planning and design. Various scholars of urban space have identified a lack of interaction (Gehl 2011, Peter Hall 2011), absence of life in the streets (La Cecla 2012, Scully 2003), loss of social capital (Putman 1996, Olenburg 1989), and disminishing equity (Zukin 2010, Harvey 1997) in public spaces. We view this as a need for conviviality (Simon & Belran 2015). This paper continues our ongoing research, identifying a set of factors of conviviality and proposing metrics for post-occupancy evaluation of existing public spaces. Three broad branches are identified as necessary conditions for convivial environments: physical spaces that are flexible, changing and adaptable; processes and outcomes based in equity, integrity and democracy; and urban uses and solutions that correspond to people’s needs and desires. Within each branch we propose key factors that influence the level of conviviality, as well as ways to identify and evaluate them. The combination of all these factors ultimately creates convivial environments. A better understanding of design for conviviality can inform architects, landscape architects, urban designers and planners to improve the public realm at the scale of the street, the neighborhood and the city.
Two-scale topology optimization in computational material design: an integrated approach Ferrer Ferré, Àlex; Cante Terán, Juan Carlos; Hernández Ortega, Joaquín Alberto; Oliver Olivella, Xavier In this work, a new strategy for solving multiscale topology optimization problems is presented. An alternate direction algorithm and a precomputed offline microstructure database (Computational Vademecum) are used to efficiently solve the problem. In addition, the influence of considering manufacturable constraints is examined. Then, the strategy is extended to solve the coupled problem of designing both the macroscopic and microscopic topologies. Full details of the algorithms and numerical examples to validate the methodology are provided.
"The City without qualities", from the book of Robert Musil: theoretical and analytical essay about a fragment of the city of Lisbon
"The City without qualities", from the book of Robert Musil: theoretical and analytical essay about a fragment of the city of Lisbon Zúquete, Ricardo Ensaio teórico e analítico desde um trabalho de investigação projectual com um grupo de estudantes de mestrado integrado, em torno de um fragmento da cidade de Lisboa num dos seus principais eixos - a Avenida Fontes Pereira de Melo. Um corpo de reflexões críticas sobre a complexidade da cidade aos dias de hoje, enquanto suporte edificado da “malha da sociedade” e dos seus “fios delicados e invisíveis”, como dizia Georg Simmel sobre o que viria a ser a sociedade moderna. Sobre o sentido da Antropologia do espaço enquanto epistemologia de suporte a uma consciente intervenção urbana, desde escritos de Georg Simmel, Claude Lévi-Strauss, Henri Lefebvre e Marc Augé, que nos oferecem uma estrutura hermenêutica profundamente válida para uma leitura acertada da complexidade deste fragmento urbano em estudo. Este trabalho/ensaio com o grupo de arquitectos finalistas e mestrandos, servirá como um alerta e uma desejável tomada de consciência para uma refiguração da postura profissional e da práxis do arquitecto, pelo um novo entendimento que moldará o devir desta nova geração. As belas pinturas de uma cidade triste e solitária de Mário Sironi ilustram, e a metáfora ao “Homem sem qualidades” de Musil complementa este ensaio e as suas provocações.; A theoretical and analytical essay from a project-oriented research work with a group of Master students concerning a fragment of the city of Lisbon in one of its principal axes – Fontes Pereira de Melo Avenue. A body of critical reflections on the complexity of the city to this day, as a built support of “society’s net” and its “delicate and invisible wires ", as Georg Simmel once wrote about what modern society would become. It is about the meaning of spatial Anthropology as a supporting epistemology to a conscious urban intervention, taking from the writings of Georg Simmel, Claude Lévi-Strauss, Henri Lefebvre and Marc Augé, which offer us a hermeneutic structure profoundly valid for an analytical reading of the complexity of this urban fragment in study. This essay and investigation with this group of finalists of architecture and Master students, will also serve as a warning and a desirable awareness of a reconfiguration of the professional attitude and the praxis of the architect, through a new understanding that will shape the future of this new generation. The beautiful paintings of the sad and lonely modern city of Mario Sironi illustrate it, and the metaphor of Robert Musil novel, "The Man without qualities", complements this essay and its provocations.
Semillero técnico + 1/2: formación de conciencia social y competencias investigativas para futuros arquitectos: Popayán-Colombia
Semillero técnico + 1/2: formación de conciencia social y competencias investigativas para futuros arquitectos: Popayán-Colombia Vargas Agredo, Liliana Considerando la imperiosa necesidad de formar a los futuros arquitectos de Colombia, como profesionales conocedores de los escenarios físicos, las condiciones socio - económicas, ambientales y culturales locales, nacionales e internacionales, a través de procesos de carácter académico e investigativo, la Fundación Universitaria de Popayán- FUP a través de la Facultad de Arquitectura y el Semillero TECNIO + 1/2, buscan promover la participación de los estudiantes en el desarrollo de proyectos de investigación de diferente índole, privilegiando la participación en el diagnóstico de la realidad social, fortaleciendo las capacidades investigativa, crítica, creativa y de argumentación. El semillero inició su proceso, en el año 2013 con el proyecto de investigación: Identificación del riesgo por inundación del rio Molino, en la infraestructura física del sector salud - comuna 3 - Popayán, como aporte a la gestión del riesgo municipal; temática relacionada con la Planificación Urbana y la Gestión del Riesgo de Desastres; en una ciudad que presenta un alto nivel de vulnerabilidad frente al desbordamiento de sus principales fuentes hídricas, al igual que amenazas naturales por remoción en masa y sismos; sin que se apliquen efectivamente estudios de conocimiento y reducción del riesgo a nivel territorial, que involucren tanto a expertos como a la comunidad afectada. Actualmente el semillero avanza su trabajo en el proyecto: Acciones pedagógicas con aplicación de TIC para la salvaguardia de las procesiones de Semana Santa en Popayán-Colombia, dirigidas a la primera infancia y la juventud, abordando una problemática de indiferencia social y crisis del sentido de pertenencia de la comunidad, debido a las migraciones post-terremoto del año 1983 y la compleja situación de orden público que vive la región y el País, aspectos que se reflejan en esta celebración declarada por la UNESCO, como patrimonio oral e inmaterial de la humanidad en el año 2009. Estos ejercicios que aplican la metodología de “aprender haciendo” involucran procesos descriptivos y analíticos, que destacan los elementos esenciales del problema de investigación, a través de la experiencia, el análisis de la misma, las lecciones aprendidas y la aplicación a futuro, permitiendo fortalecer en los estudiantes de arquitectura, sus conocimientos sobre el territorio, la comunidad y el trascendental papel de la arquitectura, como generadora de espacios que a diferente escala, intervienen en la conservación y sostenibilidad del patrimonio natural y artificial: material e inmaterial que debe valorar y proteger toda comunidad en el mundo entero.
Campos ciegos: el espacio imaginario en la educación Pozo Bernal, Melina; Mayoral Campa, Esther Nos hemos olvidado de la capacidad evocadora de la Arquitectura y del paisaje; aquello que llamaba Kahn lo inmensurable: las sensaciones, los sueños, la imaginación…. El concepto de campo ciego, muy utilizado en la disciplina fotográfica en general y por los surrealistas en la primera mitad del siglo XX es un mecanismo indispensable para la configuración de una arquitectura que construya la narración necesaria para la cualificación del espacio educativo. Se define así: Dentro de un encuadre aparece algo que tiene la capacidad de transportarnos más allá del espacio inicial, que es capaz de activarnos la ensoñación, y en definitiva recuperar nuestro imaginario y hacernos cómplices y conscientes de nuestro entorno. Los espacios que experimentamos al igual que la poesía, tienen la capacidad de modificar estados de ánimo y predisponernos a ciertas actividades. El carácter de permanencia que lleva implícito espacio educativo requiere de estas estrategias para incentivar la motivación y estimular el aprendizaje. La materialidad de la arquitectura es capaz de generar expectación y ha sido así a lo largo de toda su historia: trampantojos, especulares, duplicidades, rememoraciones, desequilibrios… La manipulación espacial en la escuela por parte de los niños es indispensable para que ellos mismos creen sus propias historias, sus propios espacios para la fantasía. Al igual que sabemos que los cuentos son parte indispensable para la formación de los nuevos individuos, la arquitectura necesita conceder espacios para el ensanchamiento de la mirada: La barriga del Lobo, la casa de Hansel y Gretel, El tronco del árbol de Alicia, la ciudades invisibles de Calvino… La comunicación desarrollará uno de los espacios surgidos a tenor de la clasificación del espacio educativo según la experiencia espacial y la pedagogía propuesta en el aprendizaje, como principal aportación del trabajo de tesis como escenario desde el que otear el horizonte arquitectónico de la escuela a través del caleidoscopio de la pedagogía. Se analizan ejemplos arquitectónicos basados en necesidades pedagógicas y conceptos arquitectónicos con los que trabajar en el futuro en la generación de un espacio educativo cualificado.; We have forgotten the evocative capacity of Architecture; what Kahn called it inmensurable: sensations, dreams, imagination…. The concept of blind field, very used in the photographic discipline in general and by Surrealism in the first half of the century XX, is an indispensable mechanism for the configuration of a necessary narrative architecture in the qualification of educative space. It is defined thus: Within frame there appears something that has the capacity to transport us to beyond the initial space, that is able to actívate reverie in us, and recovering our imagination one and make conscious accomplices tof our surroundings. Spaces that we experience like poetry, have the capacity to modify moods and ready for certain activities. The character of permanence that takes implicit educative space requires of these strategies to stimulate motivation and to stimulate learning. The materiality of the architecture is able to generate a sense of expectancy and has been thus throughout all its history: visusl tricks, mirrored images, duplicities, recollections, imbalances… Space manipulation on the part of children in school is indispensable so that they themselves create their own stories, their own spaces for fantasy. we also know that stories are indispensable part of the formation of new individuals, architecture needs to grant spaces for the widening of the glance: The belly of the Wolf, the house of Hansel and Gretel, the trunk of the tree of Alicia, The invisible cities of Calvin… The communication will develop one of the new spaces arisen in a educative space by spatial experience & pedagogic system classification generated in the PhD work like a scene from which to spy on architectonic horizon of school through a pedagogic kaleidoscope. Architectonic examples based on pedagogical necessities and architectonic concepts are analyzed which in the future will generated a qualified educative space.
Semiotic process of the office configuration Najjar Mansour, Ons Our research focuses on the study of the relationship between object and space within a context of spatial configuration in relation to the service activity, and commonly known as the office. The "office" considered as a concept, is subject to a multiple interactions that connects the office space, the office-object and the activity or office-features. Based on the specificity of the "office" activity we wonder how the development of the activity takes place in a particular spatiality that can restrict an object to the scale of the operation or a configuration that includes the user. How does the office fit into a dynamic relationship between object and space? In order to expose the mechanisms of this interactivity (Between object and space) that semiotics method would be a great contribution to identify the signs1 and the symbolic dimensions as a result of changes in the society. To answer these questions we organized our thinking around two areas: 1- we explore the definition of office entity (object/space), as it passed in diachronic, paying particular attention to the changes in context and the symbolic features. 2-Second, the semiotic study that will be used to identify the office as an articulated system and will thereby proceed to the analysis of syntagmatic and paradigmatic forms and structures that characterize the different contexts of architectural production. Ultimately, this work would in a sense validate (If we may say so), the hypothesis that the evolution of cognitive development of the office space is in relation with the dynamics of the evolving technology. While aiming to feasibility and maximum profitability, it reduces labor time, limits the use of space, and makes the job done remotely. However, we will focus on the evolutionary process of the office. The sustained office configuration (whatever it is) cannot be conceived disregarding the accumulation "of successive states of the office" or without selection, according to the law of renewal / replaces the unnecessary element that allows the office to continue exist. It is then possible to understand that as an object, the office considered as based on responding to functional need in the first place; the process of its evolution will be an answer to a specific cultural code of a specified period. Understanding by analyzing phases and their ways of articulation allows us to read the softness - of the boundary between furniture (Desk) as configuration where the activity takes place and the building (the office space) designed for the same purpose while having a different configuration. This research has attempted to highlight how sustainability evidenced by this office since ancient times reflects the quest of a man's "tool" each adapted to new contexts, that helps achieve optimal management of both physical and, virtual, immeasurable products data exchange.
Modernidad y tradición en el diseño arquitectónico ambiental Nieto Bedoya, Marta