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UPCommons, el portal d'accés obert al coneixement de la UPC, està format pel conjunt de dipòsits institucionals oberts de la UPC i té com a missió garantir la preservació de la producció docent i de recerca cientificotècnica de la Universitat, maximitzant-ne la visibilitat i, conseqüentment, incrementant-ne l’impacte en la docència i la recerca de tot el món.
Actualitzat: fa 2 hores 14 minuts

Latency tolerant branch predictors

dj., 09/14/2017 - 13:34
Latency tolerant branch predictors Santana Jaria, Oliverio J.; Ramírez Bellido, Alejandro; Valero Cortés, Mateo The access latency of branch predictors is a well known problem of fetch engine design. Prediction overriding techniques are commonly accepted to overcome this problem. However, prediction overriding requires a complex recovery mechanism to discard the wrong speculative work based on overridden predictions. In this paper, we show that stream and trace predictors, which use long basic prediction units, can tolerate access latency without needing overriding, thus reducing fetch engine complexity. We show that both the stream fetch engine and the trace cache architecture not using overriding outperform other efficient fetch engines, such as an EV8-like fetch architecture or the FTB fetch engine, even when they do use overriding.
Categories: Novetats

Modelado de personajes 3D y animación mediante captura de movimiento

dj., 09/14/2017 - 13:20
Modelado de personajes 3D y animación mediante captura de movimiento Sánchez Penella, Pau En este trabajo se toma una referencia de una escena de la película “El Señor de los Anillos: Las dos Torres” en la que el personaje de cgi Gollum habla consigo mismo. El objetivo ha sido replicar esta escena, para ello se han buscado referentes visuales de diversas fuentes, se ha creado un storyboard y unos blueprints a partir de los cuales se ha modelado el personaje en 3D, se han utilizado técnicas de captación de movimiento corporal y facial para la animación. Se han investigado diferentes métodos de captura de movimiento y se han utilizado los que se encontraban más al alcance del estudiante. Mediante una cámara Kineckt de Xbox one y software específico se ha llevado a cabo esta tarea. Este método de captación de movimiento se encuentra dentro del grupo de captación de movimiento sin marcadores que, igual que la animación manual, requiere el uso de morphs y de sistemas de huesos. De este modo, el resultado final, es el fruto de una animación capturada y posteriormente refinada y enriquecida de manera manual. Se ha compuesto la escena que consta del escenario, el personaje, varias luces y las cámaras, mediante las cuales se ha intentado crear una narrativa audiovisual similar a la de la película original. Se han usado técnicas de render fotorrealistas con materiales de sub-surface scattering y con el motor Mental ray. Los diferentes elementos que componen la escena han sido renderizados independientemente y compuestos posteriormente en postproducción en dónde también se han aplicado los retoques de corrección de color pertinentes. Asimismo, se han sacado canales de render complementarios como pelo, luz de efecto para lograr un acabado más realista. Por último, se ha creado una entradilla en 2D para presentar el trabajo en la que se ha replicado la tipografía de la saga y se ha creado un efecto mediante partículas de descomposición en granos de arena.
Categories: Novetats

Producció d'art per un videojoc de Realitat Virtual

dj., 09/14/2017 - 13:14
Producció d'art per un videojoc de Realitat Virtual Serna López, Daniel En aquest Treball Final de Grau es pretén crear un prototip de videojoc en Realitat Virtual de temàtica ""sci-fi"", explicant de forma més detallada el procés creatiu audiovisual (modelatge 3D, texturitzat, animació, so...), per tal d'assimilar el flux de treball que comporta la creació d'un videojoc d'aquestes característiques. Per procurar un resultat final satisfactori s'ha de fer un treball exhaustiu de planificació i recerca prèvia, amb l'objectiu d'organitzar-se degudament, entendre com està el mercat i quins elements poden servir de referència pel videojoc a desenvolupar; dibuixar ""Concept Art"", modelar tenint en compte l'optimització posterior, texturitzar, animar, il•luminar, cuidar-se del so, ocupar-se que tot el joc sigui coherent i tots els elements que el conformin tinguin certa cohesió. Així doncs, al llarg d'aquest treball, s'anirà recorrent les diferents fases del procés creatiu, explicant els detalls en cada etapa i problemes que han sorgit.
Categories: Novetats

Aplicació Routines

dj., 09/14/2017 - 13:12
Aplicació Routines Solé Llobet, Francesc Aquest projecte consisteix en el desenvolupament d’una aplicació híbrida amb Phonegap, anomenada Routines, programada bàsicament amb els llenguatges HTML5, CSS (SASS), JavaScript (jQuery), MySQL i PHP i aplicant altres tecnologies esmentades al llarg del treball. La temàtica de Routines és la salut, i el seu objectiu principal és el seguiment de l’estil de vida de les persones, permetent una gestió dels aspectes més comuns en el dia a dia, com per exemple l’exercici físic, l’alimentació i la hidratació. El funcionament d’aquesta aplicació es basa en la recol·lecció de les dades que els usuaris introdueixen, com per exemple els aliments que ingereixen, l’aigua que beuen i l’exercici físic que realitzen, i extreure’n resultats, mostrats en forma de gràfiques i progressos. A més a més permet la creació de rutines d’entrenament i de dietes, d’aquesta manera es pot tenir un procés a seguir per tal d’aconseguir els objectius que un mateix es proposa.
Categories: Novetats

FOODIEFY, más que una APP de recetas

dj., 09/14/2017 - 12:11
FOODIEFY, más que una APP de recetas Ytarte Gil, Roger El presente proyecto aborda la realización en términos de conceptualización y diseño de una app de recetas y cocina llamada Foodiefy, con el objetivo de satisfacer las necesidades de todas aquellas personas que a la hora de cocinar no saben qué hacer o cómo. En nuestra app como punto innovador encontraremos nuestra herramienta principal, el buscador, en él podremos buscar recetas según los ingredientes o mediante el nombre.
Categories: Novetats

A comparative study of methods for estimating virtual flux at the point of common coupling in grid connected voltage source converters with LCL filter

dj., 09/14/2017 - 11:12
A comparative study of methods for estimating virtual flux at the point of common coupling in grid connected voltage source converters with LCL filter Fazlin Roslan, Nurul; Suul, Jon Are; Rocabert Delgado, Joan; Rodríguez Cortés, Pedro Grid synchronization based on Virtual Flux (VF) estimation allows for control of grid-connected power converter without depending on AC-voltage measurements. This is useful in voltage-sensor-less applications for reducing cost and complexity of the control hardware, and can be utilized in case of limited reliability or availability of voltage measurements at the intended point of synchronization to the grid. However, for Voltage Source Converters (VSC) with LCL filters, the influence of the capacitor current must be taken into account to ensure accurate VF estimation at the Point of Common Coupling (PCC) with the grid. This paper presents a comparative evaluation of three VF-based methods for grid synchronization of VSCs with LCL filters, with three different ways of obtaining the capacitor current. The VF estimation in the first method is based only on the measured converter currents. The second method includes capacitor voltage measurements used for estimating the capacitor currents, while the capacitor currents are measured in the third approach. Comparative results from time-domain simulations are presented demonstrating good performance of the estimation and accurate control of the active and reactive power at the PCC with all three methods, as long as sufficiently accurate filter parameters and current measurements are available. However, the approach based on capacitor current measurements is sensitive to noise due to the high ripple current compared to the fundamental frequency current in the capacitors. The operation of a converter with VF-based grid synchronization including estimation of the capacitor current is demonstrated by experimental results, verifying the voltage sensor-less operation with LCL-filter.
Categories: Novetats

Class-weighted convolutional features for visual instance search

dj., 09/14/2017 - 10:40
Class-weighted convolutional features for visual instance search Jiménez, Albert; Alvarez, Jose M.; Giró Nieto, Xavier Image retrieval in realistic scenarios targets large dynamic datasets of unlabeled images. In these cases, training or fine-tuning a model every time new images are added to the database is neither efficient nor scalable. Convolutional neural networks trained for image classification over large datasets have been proven effective feature extractors for image retrieval. The most successful approaches are based on encoding the activations of convolutional layers, as they convey the image spatial information. In this paper, we go beyond this spatial information and propose a local-aware encoding of convolutional features based on semantic information predicted in the target image. To this end, we obtain the most discriminative regions of an image using Class Activation Maps (CAMs). CAMs are based on the knowledge contained in the network and therefore, our approach, has the additional advantage of not requiring external information. In addition, we use CAMs to generate object proposals during an unsupervised re-ranking stage after a first fast search. Our experiments on two public available datasets for instance retrieval, Oxford5k and Paris6k, demonstrate the competitiveness of our approach outperforming the current state-of-the-art when using off-the-shelf models trained on ImageNet.
Categories: Novetats

New benchmarking methodology and programming model for big data processing

dj., 09/14/2017 - 09:48
New benchmarking methodology and programming model for big data processing Kos, Anton; Tomažic, Sašo; Salom, Jakob; Trifunovic, Nemanja; Valero Cortés, Mateo; Milutinovic, Veljko Big data processing is becoming a reality in numerous real-world applications. With the emergence of new data intensive technologies and increasing amounts of data, new computing concepts are needed. The integration of big data producing technologies, such as wireless sensor networks, Internet of Things, and cloud computing, into cyber-physical systems is reducing the available time to find the appropriate solutions. This paper presents one possible solution for the coming exascale big data processing: a data flow computing concept. The performance of data flow systems that are processing big data should not be measured with the measures defined for the prevailing control flow systems. A new benchmarking methodology is proposed, which integrates the performance issues of speed, area, and power needed to execute the task. The computer ranking would look different if the new benchmarking methodologies were used; data flow systems would outperform control flow systems. This statement is backed by the recent results gained from implementations of specialized algorithms and applications in data flow systems. They show considerable factors of speedup, space savings, and power reductions regarding the implementations of the same in control flow computers. In our view, the next step of data flow computing development should be a move from specialized to more general algorithms and applications.
Categories: Novetats

Synchronous power control of grid-connected power converters under asymmetrical grid fault

dj., 09/14/2017 - 09:48
Synchronous power control of grid-connected power converters under asymmetrical grid fault Zhang, Weiyi; Rocabert Delgado, Joan; Candela García, José Ignacio; Rodríguez Cortés, Pedro Control of grid-connected power converters is continuously developing to meet the grid codes, according to which the generation units should keep connected to the grid and further provide ancillary services, such as voltage and frequency support, negative sequence current injection, inertia emulation, etc. A virtual admittance controller is proposed in this paper for the objective of voltage support under asymmetrical grid faults. By using independent and selective admittances for positive and negative sequence current injection, the unbalanced voltage can be significantly compensated during asymmetrical faults. The controller is based on the generic control framework of the synchronous power controller (SPC), which is able to control a power converter with emulated and improved synchronous generator characteristics. Simulation and experimental results based on two paralleled 100 kW grid-connected power converters demonstrate the controller to be effective in supporting unbalanced voltage sags.
Categories: Novetats

Surface behavior of aprotic mixtures: dimethyl sulfoxide/acetonitrile

dc., 09/13/2017 - 21:12
Surface behavior of aprotic mixtures: dimethyl sulfoxide/acetonitrile Rodriguez, Javier; Elola, M. Dolores; Martí Rabassa, Jordi; Laria, Daniel We present results from molecular dynamics simulations that examine microscopic characteristics of mixtures combining acetonitrile (ACN) and dimethyl sulfoxide (DMSO) at the vicinity of liquid/air and liquid/graphene interfaces. In the former interfaces, our simulations reveal a clear propensity of ACN to lie adjacent to the vapor phase at all concentrations. A simple model based on the consideration of a chemical equilibrium between bulk and surface states was found to be adequate to reproduce simulation results. Orientational correlations at the interface showed a mild tendency for dipolar aligments pointing toward the vapor phase in ACN-rich solutions; contrasting, in DMSOrich mixtures, the preferential orientations looked mostly parallel to the interface. Close to graphene plates, the local scenarios reverse and local concentrations of DMSO are larger than the one observed in the bulk. Dynamical results reveal that the characteristic time scales describing orientational relaxations and residence times at the interfaces stretch as the concentration of ACN diminishes. For liquid/air interfaces residence times for ACN were found to be larger than those for DMSO. A classical treatment for the predictions of the C-H stretching band of the IR peaks in the bulk and at the interfaces reveals shifts that agree with experimental measurements.
Categories: Novetats

Adaptation and validation of the motivated strategies for learning questionnaire-mslq-in engineering students in Colombia

dt., 09/12/2017 - 13:54
Adaptation and validation of the motivated strategies for learning questionnaire-mslq-in engineering students in Colombia Ramírez Echeverry, Jhon Jairo; García Carrillo, Àgueda; Olarte Dussan, Fredy Andres With the aim of characterizing self-regulated learning of engineering students in a Colombian university, students were asked to answer a Spanish version of the Motivated Strategies for Learning Questionnaire (MSLQ); this questionnaire enables obtaining information on epistemic motivation and learning strategies of the students in the courses they are studying. The data found suggest the dimensional structure of the questionnaire did not meet the context of those students. It was decided to make a new translation of the MSLQ into Spanish and make linguistic and cultural adaptations in order to achieve a valid instrument; this work began with the International Test Commission (ITC) guidelines. As a result, a new questionnaire was attained, MSLQ- Colombia. The objective of this article is to present the method used to obtain the MSLQ-Colombia, and the study of the psychometric properties of the new questionnaire. The psychometric properties studied were the construct validity, content validity and reliability. These properties were determined by factor analysis, Cronbach’s Alpha and experts consultation. The participants of this research were 1218 engineering students and 12 university teachers. The results indicate the new questionnaire is valid and reliable, provide information to those who may use MSLQ-Colombia to comprehend the results of their investigations, and offer the international community new empirical evidences on MSLQ psychometric properties. It led to the conclusion that the MSLQ- Colombia has similar psychometric properties to the original MSLQ in English, and that the new questionnaire can be useful for the Spanish speaking international community. This article can be a valuable guide for those researchers, who desire making translations-adaptations of the MSLQ into languages-cultures different from English or Spanish, and also, to translate-adapt questionnaires of self-report besides the MSLQ.
Categories: Novetats

A methodology to discover and understand complex patterns: interpreted integrative multiview clustering (I2MC)

dt., 09/12/2017 - 13:46
A methodology to discover and understand complex patterns: interpreted integrative multiview clustering (I2MC) Sevilla-Villanueva, Beatriz; Gibert, Karina; Sànchez-Marrè, Miquel The main goal of this work is to develop a methodology for finding nutritional patterns from a variety of individual characteristics which can contribute to better understand the interactions between nutrition and health, provided that the complexity of the phenomenon gives poor performance using classical approaches. An innovative methodology based on a combination of advanced clustering techniques and consistent conceptual interpretation of clusters is proposed to find more understandable patterns or clusters. The Interpreted Integrative Multiview Clustering (I2MC) combines the previously proposed Integrative Multiview Clustering (IMC) with a new interpretation methodology NCIMS. IMC uses crossing operations over the several partitions obtained with the different views. Comparison with other classical clustering techniques is provided to assess the performance of this approach. IMC helps to reduce the high dimensionality of the data based on multiview division of variables. Two innovative Cluster Interpretation methodologies are proposed to support the understanding of the clusters. These are automatic methods to detect the significant variables that describe the clusters; also, a mechanism to deal with the consistency between the interpretations inter clusters of a single partition CI-IMS, or between pairs of nested partitions NCIMS. Some formal concepts are specifically introduced to be used in the NCIMS. I2MC is used to validate the interpretability of the participant’s profiles from an intervention nutritional study. The method has advantages to deal with complex datasets including heterogeneous variables corresponding to different topics and is able to provide meaningful partitions.
Categories: Novetats

Application with data acquisition of a FESTO planar surface gantry EXCM

dt., 09/12/2017 - 13:25
Application with data acquisition of a FESTO planar surface gantry EXCM Vilanova Bernal, Xavier The following document contains the Final Project Degree of Xavier Vilanova Bernal. It is based on process automation in the field of biomedicine and trying to facilitate the work of a biologist and / or doctor. The implementation of this project is to cultures microorganisms in petri dishes, which so far have been managed manually, can make a big improvement in many aspects for laboratories and hospitals. For this purpose, it has been designed, developed and manufactured a prototype containing a 3-axis robot, an adapted clamp and an OpenSource controller with connectivity to a communication platform with Smartphones. Throughout the entire document has everything you need to understand and reproduce this prototype; El següent document conté el Projecte de Final de Grau (PFG) de Xavier Vilanova Bernal. Es basa en l'automatització de processos en l'àmbit de la biomedicina i que intenta facilitar les tasques d'un biòleg i / o mèdic. L'aplicació d'aquest projecte és als cultius de microorganismes en les plaques de Petri, que fins al moment s'han gestionat de manera manual, pot suposar una gran millora en molts aspectes per a laboratoris i hospitals. Per a aquesta finalitat, s'ha dissenyat, desenvolupat i fabricat un prototip que conté un robot de 3 eixos, una pinça adaptada i una controladora OpenSource amb connectivitat a una plataforma de comunicació amb Smartphones. Al llarg de tot el document es trobarà tot el necessari per entendre i reproduir aquest prototip; El siguiente documento contiene el Proyecto de Final de Grado (PFG) de Xavier Vilanova Bernal. Se basa en la automatización de procesos en el ámbito de la biomedicina y que intenta facilitar las labores de un biólogo y/o médico. La aplicación de este proyecto es a los cultivos de microorganismos en las placas de Petri, que hasta el momento se han gestionado de manera manual, puede suponer una gran mejora en muchos aspectos para laboratorios y hospitales. Para esta finalidad, se ha diseñado, desarrollado y fabricado un prototipo que contiene un robot de 3 ejes, una pinza adaptada y una controladora OpenSource con conectividad a una plataforma de comunicación con Smartphones. A lo largo de todo el documento se encontrará todo lo necesario para entender y reproducir este prototipo
Categories: Novetats

Les observacions i mesures de Pietro Mengoli (1627-1686) a la meridiana de Sant Petronio

dt., 09/12/2017 - 13:08
Les observacions i mesures de Pietro Mengoli (1627-1686) a la meridiana de Sant Petronio Massa Esteve, Maria Rosa Durant els segles XVII i XVIII van ser traçades diverses línies meridianes a l’interior de les catedrals europees de Florència, Bolonya, Roma i Paris que van servir per determinar la longitud de l’any solar a través de mesures precises i contínues de la posició del Sol. En trobem referències directes del segle XVII en els treballs de Pietro Mengoli (1627-1686) i Giovanni D. Cassini (1625-1712). Mengoli, deixeble de Cavalieri, seguidor de Viète, després de publicar obres de matemàtica pura molt originals, va passar uns anys, de 1660 a 1670, sense publicar res i retirat a la seva església de Santa Mª Magdalena. És en aquesta època que col·laborà en astronomia fent observacions a la meridiana de Sant Petronio de Bolonya. El propòsit d’aquest text és reflexionar sobre el significat de les mesures i observacions fetes per Mengoli que es troben explicades a la seva obra: Refrattioni e ParallasseSolare (Bolonya, 1670). Aquesta obra és una de les primeres referències textuals d’ús de les línies meridianes com instruments de mesura astronòmiques del segle XVII. Analitzarem el contingut del text i de les cartes de Cassini que critiquen els principis i les conclusions que se’n deriven del llibre de Mengoli.
Categories: Novetats

Development of a multimaterial additive manufacturing process for electronic devices

dt., 09/12/2017 - 12:46
Development of a multimaterial additive manufacturing process for electronic devices Muguruza Blanco, Asier; Bonada Bo, Jordi; Gómez Fernández, Agustín; Minguella Canela, Joaquim; fernandes, joana; Ramos, Francisco; Xuriguera Martin, Elena; Varea Espelt, Aida; Cirera Hernandez, Albert In order to increase the versatility of additive manufacturing multimaterial processes, a hybrid system has been developed, which is capable of combin ing 3D printing technology by DLP (Digital Light Processing) with a two - dimensional Drop - on - Demand Inkjet printing system. Through DLP technology based on digital micromirror devices (DMDs) it is possible to build up 3D geometries layer - by - layer using polyme rization of photo sensitive resins. Concurrently, while the construction process is performed, the I nk J et printing system is used to deposit tiny drops of conductive inks on the substrate generated, which will thus constitute an electric circuit embedded within the three dimensional structure. On the other hand, photo sensitive resins have been filled with Low Te mperature Co - f iring Ceramic (LT CC) particles , in order to modify the basis properties of the part by using sinterizable slurries. Finally the challenges in the sintering process for achieving functional parts are discussed and a few prototypes have been built in order t o validate this technology
Categories: Novetats

Instalación y puesta en marcha de un Programmable Automation Controller (PAC) y un sistema de supervisión en el laboratorio de Control Industrial

dt., 09/12/2017 - 12:40
Instalación y puesta en marcha de un Programmable Automation Controller (PAC) y un sistema de supervisión en el laboratorio de Control Industrial López Fernández, Antoni
Categories: Novetats

Influence of exposure time on mechanical properties and photocuring conversion ratios for photosensitive materials used in additive manufacturing

dt., 09/12/2017 - 12:18
Influence of exposure time on mechanical properties and photocuring conversion ratios for photosensitive materials used in additive manufacturing Bonada Bo, Jordi; Muguruza Blanco, Asier; Fernández Francos, Xavier; Ramis Juan, Xavier The influence of UV post - curing process on mechanical properties as well as photocuring conversion ratios is presented. An analytical model to determinate the conversion ratio for frontal polymerization is used t o define 3D printing parameters in order to obtain a conversion profile as homogeno us as possible. The mechanical properties of 3D p rinted coupons with and without UV post - curing process were obtained through experimental tensile and bending tests. Furthermore, the experimental conversion ratios of printed samples were obtained by means of FTIR spectrometry analysis. It was observed that conversion ratios and some mechanical properties increase because of UV post - curing treatment, enabling the chance to optimize the whole manufacturing process in function of the 3D printed part requiremen ts.
Categories: Novetats

To distribute or not to distribute: The question of load balancing for performance or energy

dt., 09/12/2017 - 11:52
To distribute or not to distribute: The question of load balancing for performance or energy Stafford, Esteban; Pérez, Borja; Bosque, Jose L.; Beivide Palacio, Ramon; Valero Cortés, Mateo Heterogeneous systems are nowadays a common choice in the path to Exascale. Through the use of accelerators they offer outstanding energy efficiency. The programming of these devices employs the host-device model, which is suboptimal as CPU remains idle during kernel executions, but still consumes energy. Making the CPU contribute computin effort might improve the performance and energy consumption of the system. This paper analyses the advantages of this approach and sets the limits of when its beneficial. The claims are supported by a set of models that determine how to share a single data-parallel task between the CPU and the accelerator for optimum performance, energy consumption or efficiency. Interestingly, the models show that optimising performance does not always mean optimum energy or efficiency as well. The paper experimentally validates the models, which represent an invaluable tool for programmers when faced with the dilemma of whether to distribute their workload in these systems.
Categories: Novetats

DIMP: A low-cost diversity metric based on circuit path analysis

dt., 09/12/2017 - 11:29
DIMP: A low-cost diversity metric based on circuit path analysis Alcaide, Sergi; Hernandez, Carles; Roca Rosell, Antoni Maria Claret; Abella, Jaume Diversity has been regarded as a desirable property of redundant instances, since it allows circuits to behave differently in front of a given fault. However, while qualitatively diversity is a well-understood concept, usable efficient metrics do not exist to quantify diversity in the context of safety-related systems. In this paper we cover this gap by proposing DIMP, a low-cost diversity metric based on analyzing the paths of the redundant circuits. We relate it to the particular case of automotive microcontrollers implementing lockstep cores and show that it can be successfully used providing relevant information for addressing common cause faults.
Categories: Novetats

Event-based control for sit-to-stand transition using a wearable exoskeleton

dt., 09/12/2017 - 11:22
Event-based control for sit-to-stand transition using a wearable exoskeleton Rajasekaran, Vijaykumar; Vinagre Ruiz, Manuel; Aranda López, Juan Sit-to-stand transition is an essential step in a lower limb rehabilitation therapy, mainly for assisting the patient to transit from wheel chair to the next level of therapy. A mixed stiffness-damping control adaptation is proposed for this task which will help in reaching the final position with a constant velocity. A combination of control model is proposed to ensure the initiation and the final stage of the transition, such as to ensure stability and to maintain the equilibrium. The combined control model helps in reaching the goal position with equal participation from the user. For patient studies, such as with paraplegic patients, a combinational control model with muscle stimulation can be included to provide a complete assistance. The role of muscle stimulation and joint movement assistance is also considered in this control model. Further, final stage of this transition must ensure keeping or helping the user to maintain the upright position.
Categories: Novetats

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