http://upcommons.upc.edu/e-prints The DSpace digital repository system captures, stores, indexes, preserves, and distributes digital research material. Search the Channel search http://upcommons.upc.edu/e-prints/simple-search http://hdl.handle.net/2117/15045 Title: Analysis of the excavation of a deep drift in a tertiary clay<br/><br/>Authors: Vaunat, Jean; Gens Solé, Antonio; de Vasconcelos, R.; Li, X.-L.<br/><br/>Abstract: This paper tackles the issues related to the excavation of a horizontal gallery carried out in Boom clay, a tertiary clay that hosts the Underground Laboratory of the BelgiumNuclear Agency (SCK-CEN). The gallery is 85 m long, 5 m wide and connects one of thelaboratory access shafts to a horizontal drift drilled from the second access shaft. Displacement and pore water pressure sensors installed from both gallery ends allowed for a detailed monitoring of the hydro-mechanical response of the clay rock before, during and after gallery excavation. A striking feature of the response concerns the strong changes measured in pore water pressure at distances as large as 60m from the excavation front. To explore anddiscriminate the mechanisms controlling such pore pressure changes, 2D axisymmetric FiniteElement hydro-mechanical calculations have been carried out. An elastoplastic constitutive law based on Mohr-Coulomb criterion has been considered for the material. Several types of analyses have been performed: a) material and stress state are isotropic; b) material is isotropicbut stress state is orthotropic and, c) material and stress state are orthotropic. Results allow for explaining the field measurements and identifying the key variables that control the clay responsearound the drift. http://hdl.handle.net/2117/15044 Title: Modelling the behaviour of structured London Clay<br/><br/>Authors: González, N.A.; Gens Solé, Antonio; Arroyo Alvarez de Toledo, Marcos; Rouainia, Mohamed<br/><br/>Abstract: The paper presents a constitutive modelling of the London clay based on the detailed laboratory knowledge gathered about London clay structure (Hight et al, 2007; Gasparre et al, 2007; Gasparre & Coop, 2008). Modelling was performed using a structured kinematic hardening soil model based on Rouainia & Wood (2000). It was found that a smooth elasto-plastic transition was required to avoid a spurious stiffness degradation response. Consequently, the initial model was modified following a procedure similar to that suggested by Grammatikopoulou et al. (2006). Parameters associated with soil structure and state variables for each lithological sub-unit of the London clay are presented. A good prediction of stress-strain, strength and stiffness behaviour in the small strain range is obtained in spite of the complex behaviour observed in laboratory. The significantly different mechanical behavioursof the lithological sub-units, arising from differences in structure, are adequately reproduced. http://hdl.handle.net/2117/15043 Title: Coupled analysis of double porosity swelling clays<br/><br/>Authors: Gens Solé, Antonio; Guimarães, Leonardo do N; Sánchez, Marcelo; Valleján, Beatriz<br/><br/>Abstract: The understanding of the coupled behaviour of highly active swelling clays is better achieved considering two structural levels and their interactions in the context of a double-porosity model. Hydraulic equilibrium between the two porosity levels is not assumed. Applications to hydration swelling tests of bentonite powderpellets mixtures and to the chemomechanical behaviour of bentonites are presented. http://hdl.handle.net/2117/15042 Title: Informe técnico para el dimensionado del refuerzo de dos vigas tipo del edificio de la calle Port Salvi 149 en Sant Feliu de Guíxols (Report Nº111212-S01173)<br/><br/>Authors: Gil Espert, Lluís http://hdl.handle.net/2117/15041 Title: Diseño de un banco de ensayo para el análisis fotoelástico de una célula de carga<br/><br/>Authors: Cáceres Rodríguez, Orlan; Sánchez Romero, Montserrat http://hdl.handle.net/2117/15040 Title: Cálculo de estructura ascensor eléctrico 450 Kg con guías centradas<br/><br/>Authors: Cáceres Rodríguez, Orlan; Sánchez Romero, Montserrat http://hdl.handle.net/2117/15039 Title: Aplicacions del principi de funicularitat en les estructures comprimides: una revisió històrica<br/><br/>Authors: Romea Rosas, Carlos; Sánchez Romero, Montserrat http://hdl.handle.net/2117/15038 Title: Measure of roughness of paper using speckle<br/><br/>Authors: Pino, Abdiel; Pladellorens Mallofré, Josep http://hdl.handle.net/2117/15037 Title: Noise enhancement and SNR equivalence in Bernoulli nonuniform sampling<br/><br/>Authors: Font Segura, Josep; Vázquez Grau, Gregorio; Riba Sagarra, Jaume<br/><br/>Abstract: This paper addresses the problem of nonuniform spectral analysis and spectrum sensing by means of Bernoulli sampling. The statistical treatment of sampling shows thatnonuniformly sampling below the Nyquist rate produces in average the e ects of noise enhancement and power loss on the second-order statistics of the signal (correlation and spectrum). The main focus of the paper is to obtain an equivalence in terms of signal-to-noise ratio (SNR) to modelthe noise enhancement and power loss effects. The Bernoulli nonuniform sampling is further extended to matrix formulation, which allows the application of spectrum sensing for cognitive radio signal detection. Numerical results assess the noise enhancement eff ect and SNR equivalence in spectral analysis and spectrum sensing. http://hdl.handle.net/2117/15036 Title: Novel periodogram and Capon spectral analysis based on nonuniform sampling<br/><br/>Authors: Font Segura, Josep; Vázquez Grau, Gregorio; Riba Sagarra, Jaume<br/><br/>Abstract: The spectrum analysis problem based on the periodogram and Capon estimates from a nonuniformly sampled signal is addressed. The nonuniform sampling process is castas a linear projection matrix which encompasses several recent sampling strategies such as compressive sampling. A rank-1 correlation-matching approach is proposed to derive a general filter-bank framework that allows the formulation of the nonuniform periodogram and Capon estimates as particular cases. The performance of the novel periodogram and Capon estimates isanalyzed in a cognitive radio scenario where the primary system is a multiband signal with sparse spectrum. Both theoretical andnumerical results show that the denoising process required by correlation-matching plays an important role in spectral analysisbased on nonuniform sampling. http://hdl.handle.net/2117/15035 Title: Diseño de una aplicación de software de medición y evaluación de niveles de iluminación en vía publica mediante GPS<br/><br/>Authors: Sanz Ciria, Rubén; Sierra Garriga, Carlos<br/><br/>Abstract: Las instalaciones de alumbrado público se realizan con el objetivo de proporcionar valores lumínicos adecuados para el correcto desarrollo de la actividad humana durante la noche en las vías públicas. Tanto como para garantizar un funcionamiento adecuado tanto en términos de luz sufciente y correctamente distribuida como en términos de eficiencia de la instalación es necesario evaluar los niveles de iluminación. Los métodos habituales de evaluación suelen ser lentos y tediosos, basándose en medidas manuales a lo largo de mallas en zonas limitadas que han de ser representativas del resto, dificultando un uso más extensivo y más frecuente.La aplicación desarrollada pretende simplificar y automatizar el proceso de recolección de medidas. Para ello, montando sensores iluminancia y posición GPS en un vehículo, se pretende tomar medidas georreferenciadas del nivel de iluminancia mientras este circula por la vía. Una vez medidas y almacenadas, el programa proporciona herramientas para gestionarlas y visualizarlas, de forma que se puedan establecer comparaciones y sacar conclusiones útiles para el mantenimiento y planificación de las instalaciones. Algunas de estas herramientas son listados e informes de mediciones con valores de iluminancias y uniformidades, gráficos de evolución de iluminancia, mapas de niveles, superposición de medidas, etc. // Street lighting facilities are designed with the goal of providing adequate lighting settings for the proper development of human activity at night on public roads. It is therefore necessary to evaluate light levels to ensure that streetlights illuminate with the amount of light required and properly distributed. The usual evaluation methods tend to be slow and tedious, based on manual measurements along meshes in limited areas that need to be representative of the rest, preventing a more extensive and frequent use.The application developed tries to simplify and automate the collection of measures. To do this, illuminance and GPS sensors are mounted on a vehicle, taking georeferenced light level measurements while it is traveling on the road. Once measured and stored data, the program provides tools to manage and display it so that it’s possible to make comparisons and draw conclusions for the maintenance and facilities planning. Some of these tools are lists andmeasurements reports of illuminance and uniformity representative values, graphs ofilluminance evolution, light level maps, comparison of measures, etc. http://hdl.handle.net/2117/15034 Title: Sistemas de ayuda a la conducción para reducir emisiones y consumo de los vehículos de turismo. Estado actual, perspectivas futuras.<br/><br/>Authors: Pangallo, Roberto; González Benítez, María Margarita; Oliveras Mérida, Víctor<br/><br/>Abstract: Algunos de los aspectos fundamentales en el desarrollo de los modernos vehículos de turismo son la evolución tecnológica y la ingeniería verde.Por un lado, los componentes electrónicos en los vehículos tienen un desarrollo proporcional al de las nuevas tecnologías. La continua mejora de características como miniaturización, integración, potencial de cálculo, fiabilidad y eficiencia de costes, permite que la electrónica esté cada vez más presente en los nuevos modelos de vehículos, substituyendo y mejorando las funcionalidades de las piezas mecánicas.Por otro lado, la ingeniería verde orienta a los fabricantes de vehículos hacia soluciones que optimicen y reduzcan el consumo de energía.Palabras como seguridad, entretenimiento, comunicación, telemática, diagnóstico, eficiencia y sostenibilidad hacen de estos dispositivos unos puntos estratégicos del sector de automoción actual y futuro.Lo considerado ciencia-ficción en los años ochenta, hoy es un tema común, no solo paraaplicaciones militares, sino como sistemas económicamente viables para vehículos deturismo.El presente estudio se enfoca hacia los sistemas de ayuda a la conducción que facilitan al conductor la reducción de emisiones y de consumo. Se resaltan la importancia del factor humano y la aceptación de los usuarios; se analizan los sistemas comerciales, aquellos actualmente en desarrollo y las posibles futuras aplicaciones. // Some of the key aspects in the development of modern vehicles are the technological and environmental evolution and the green engineering. On one hand, the presence of electronic components in the vehicles is proportional to the development of new technologies. The fast and continuous technological improvement in miniaturization, integration, computational potential, reliability, cost efficiency, and other features promotes the replacing and improving the functionalities of mechanical parts.On the other hand, the green engineering drives vehicle producers to solutions that optimize and reduce energy consumption.Issues such as security, infotainment, diagnosis, efficient and sustainability make the research for these devices a strategic field in the automotive sector. Today, drive assistance systems are considered tools to compete in the market. In the eighties, a drive assistant system was considered subject for science fiction. Today it is a current theme, not only as a military application, but also as an economically viable system for passenger vehicles.The study is about drive assistance systems that allow the driver to reduce emissions andenergy consumption. We analyze human factor and users’ acceptance; we treat the systemsthat have already commercialized, the ones that are under development, and all the solutions that could become the next market application. http://hdl.handle.net/2117/15033 Title: Organización espacial de las células de precipitación y ampliación del cálculo de la lluvia de diseño en el área metropolitana de Barcelona. Tercer informe para el proyecto SW0801<br/><br/>Authors: Casas Castillo, M. del Carmen; Rodríguez Solá, Raúl; Navarro, Xavier; Redaño Xipell, Ángel<br/><br/>Abstract: Tercer informe para el proyecto SW0801. Fase 2: Medium & long term strategies to manage flooding events in urban and peri-urban areas http://hdl.handle.net/2117/15032 Title: Coordinated MIMO precoding for power minimization in femtocell systems<br/><br/>Authors: Muñoz Medina, Olga; Vidal Manzano, José; Agustín de Dios, Adrián; Pascual Iserte, Antonio; Barbarossa, Sergio http://hdl.handle.net/2117/15031 Title: Multi-command SSVEP BCI system based on constrained ICA with references<br/><br/>Authors: Martínez, Pablo; Vallverdú Ferrer, Montserrat; Cichocki, Andrzej<br/><br/>Abstract: We propose a new procedure for fast and robust extraction of the Steady-State Visual Evoked Potentials (SSVEP)for an asynchronous multi-command Brain Computer Interface(BCI). The SSVEPs were elicited by means of small reversal flickering checkerboards displayed on a monitor screen. In order to extract the SSVEPs we applied a new algorithm based on Constrained Independent Component Analysis with references (CICAr). A set of references defined as rectangular half-cycle-square periodic signals with the same frequencies asthe frequencies of the flickering checkerboards were added into equality and inequality constraints, in order to extract in each moment the stronger elicited SSVEP activities. The final decision stage of the BCI system is performed by means of multiplestatistical tests using surrogate data to contrast the reliability of the extracted SSVEPs by the CICAr algorithm, achievinga good discrimination when a subject is gazing or not gazing at a checkerboard. The proposed procedure does not require aclassifier; therefore, it is not necessary to perform any calibration or training session to tune any classifier parameter, hence a plug and play BCI system. The algorithm has been tested with recorded EEG data of 4 healthy subjects from previouslypublished real-time SSVEP-based BCI experiments. The obtained results confirm a high performance of the proposed algorithm,reaching a high transfer rate of information.