Novetats

A Tabu search algorithm for scheduling independent jobs in computational grids

UPCommons - dv., 03/01/2019 - 14:42
A Tabu search algorithm for scheduling independent jobs in computational grids Xhafa Xhafa, Fatos; Carretero Casado, Javier Sebastián; Dorronsoro, Bernabé; Alba, Enrique The efficient allocation of jobs to grid resources is indispensable for high performance grid-based applications, and it is a computationally hard problem even when there are no dependencies among jobs. We present in this paper a new tabu search (TS) algorithm for the problem of batch job scheduling on computational grids. We define it as a bi-objective optimization problem, consisting of the minimization of the makespan and flowtime. Our TS is validated versus three other algorithms in the literature for a classical benchmark. We additionally consider some more realistic benchmarks with larger size instances in static and dynamic environments. We show that our TS clearly outperforms the compared algorithms.
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A singularity-robust LQR controller for parallel robots

UPCommons - dv., 03/01/2019 - 14:35
A singularity-robust LQR controller for parallel robots Bordalba Llaberia, Ricard; Porta Pleite, Josep Maria; Ros Giralt, Lluís Parallel robots exhibit the so-called forward singularities, which complicate substantially the planning and control of their motions. Often, such complications are circumvented by restricting the motions to singularity-free regions of the workspace. However, this comes at the expense of reducing the motion range of the robot substantially. It is for this reason that, recently, efforts are underway to control singularity- crossing trajectories. This paper proposes a reliable controller to stabilize such kind of trajectories. The controller is based on the classical theory of linear quadratic regulators, which we adapt appropriately to the case of parallel robots. As opposed to traditional computed-torque methods, the obtained controller does not rely on expensive inverse dynamics computations. Instead, it uses an optimal control law that is easy to evaluate, and does not generate instabilities at forward singularities. The performance of the controller is exemplified on a five-bar parallel robot accomplishing two tasks that require the traversal of singularities. © 20xx 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
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Eines digitals per a la intel·ligència col·lectiva

UPCommons - dv., 03/01/2019 - 14:34
Eines digitals per a la intel·ligència col·lectiva Monguet Fierro, José María; Trejo Omeñaca, Alejandro Trajectòria recerca-innovació en l’àmbit de les eines digitals que promouen i faciliten la implantació d’estratègies d’intel·ligència col·lectiva en entorns d’innovació. Es plantegen possibilitats de col·laboració
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Assessment of energy management in a fuel cell/battery hybrid vehicle

UPCommons - dv., 03/01/2019 - 14:26
Assessment of energy management in a fuel cell/battery hybrid vehicle Carignano, Mauro; Roda Serrat, Vicente; Costa Castelló, Ramon; Valiño, Luis; Lozano Fantoba, Antonio; Barreras Toledo, Felix Manuel The energy management strategy plays a major role in hybrid platforms powered by fuel cells (FCs) and batteries. This paper presents an assessment of energy management focused on fuel economy and battery degradation. Particularly, a proposed heuristic strategy and the widely known equivalent consumption minimization strategy are compared with the optimal solution obtained offline via dynamic programming. The case study is based on a real FC hybrid vehicle. Accordingly, the powertrain model of the vehicle used for the simulations is validated experimentally, and the profile of the power demand is measured from the real application. The results show that the proposed strategy offers the same performance as the equivalent consumption minimization strategy when the battery degradation is prioritized, and in comparison with the optimal off-line solution, it can be seen that there is still margin for improvement in terms of battery degradation. © 20xx 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
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New technologies in surgery

UPCommons - dv., 03/01/2019 - 14:17
New technologies in surgery Casals Gelpi, Alicia; Sayols Baixeras, Narcís; Amat Girbau, Josep The progress of technology and robotics in industry has not yield to an equivalent development in the medical field. This paper analyses surgical proce-dures from the point of view of industrial processes looking for analogies in both fields so as to evaluate the possibilities of using equivalent technologies in both of them. After analyzing surgical specialties from the mechanical point of view, the actions to be performed, and the main requirements as precision and working conditions, a look at the main challenges that surgical robotics should face is presented.
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The KIT swiss knife gripper for disassembly tasks: a multi-functional gripper for bimanual manipulation with a single arm

UPCommons - dv., 03/01/2019 - 14:15
The KIT swiss knife gripper for disassembly tasks: a multi-functional gripper for bimanual manipulation with a single arm Borràs Sol, Júlia; Heudorfer, Raphael; Rader, Samuel; Asfour, Tamim This work presents the concept of a robotic gripper designed for the disassembly of electromechanical devices that comprises several innovative ideas. Novel concepts include the ability to interchange built-in tools without the need to grasp them, the ability to reposition grasped objects in-hand, the capability of performing classic dual arm manipulation within the gripper and the utilization of classic industrial robotic arms kinematics within a robotic gripper. We analyze state of the art grippers and robotic hands designed for dexterous in-hand manipulation and extract common characteristics and weak points. The presented concept is obtained from the task requirements for disassembly of electromechanical devices and it is then evaluated for general purpose grasping, in-hand manipulation and operations with tools. We further present the CAD design for a first prototype. © 20xx 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.
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Towards safety in physically assistive robots: eating assistance

UPCommons - dv., 03/01/2019 - 14:11
Towards safety in physically assistive robots: eating assistance Vila Abad, Maria; Canal Camprodon, Gerard; Alenyà Ribas, Guillem Safety is one of the base elements to build trust in robots. This paper studies remedies to unavoidable collisions using robotics assistive feeding as an example task. Firstly, we propose an attention mechanism so the user can control the robot using gestures and thus prevent collisions. Secondly, when unwanted contacts are unavoidable we compare two safety strategies: active safety, using a force sensor to monitor maximum allowed forces; and passive safety using compliant controllers. Experimental evaluation shows that the gesture mechanism is effective to control the robot. Also, the impact forces obtained with both methods are similar and thus can be used independently. Additionally, users experimenting on purpose impacts declared that the impact was not harmful.
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Utilización del programa de CAD SolidWorks como herramienta para la explicación de contenidos y conceptos teóricos en ingeniería gráfica

UPCommons - dv., 03/01/2019 - 13:48
Utilización del programa de CAD SolidWorks como herramienta para la explicación de contenidos y conceptos teóricos en ingeniería gráfica Hernández Abad, Vicente; Hernández Abad, Francisco En muchas ocasiones las explicaciones conceptuales relativas a la materia de Expresión Gráfica basadas en la comprensión del espacio, resultan difíciles de entender para el alumno, posiblemente debido a que aún no ha desarrollado suficientemente la capacidad para la interpretación del espacio, algo que si bien en parte es innato, también se ejercita y se aprende. Es por ello que los profesores que imparten dicha materia suelen apoyar sus explicaciones en representaciones gráficas del espacio más comprensibles como por ejemplo las perspectivas, también frecuentemente utilizadas en enunciados de exámenes o prácticas. Por otra parte, a día de hoy, disponemos de potentes herramientas de trabajo gráfico basados en el uso del ordenador como son los programes informáticos de CAD, entre ellos Solidworks, que incorporan espacios virtuales para el trabajo tridimensional y además tienen un funcionamiento basado en parámetros dimensionales y condiciones geométricas que se pueden interrelacionar. De la combinación de los conceptos expuestos surge la idea de utilizar los espacios virtuales tridimensionales y la capacidad paramétrica del programa Solidworks, como herramienta para generar módulos didácticos de apoyo para la explicación de contenidos fundamentados en la comprensión del espacio, con la intención de mejorar la eficacia en la comprensión de las explicaciones
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Discovering Architecture

UPCommons - dj., 02/28/2019 - 16:01
Discovering Architecture Bardí Milà, Berta; Altarriba, Eduard Who built the first houses? What’s the difference between an arch and an architrave? How does a dome stay up? Who invented concrete? Can you build a house from paper? If you want to know more about the buildings around you, this entertaining illustrated guide is a perfect introduction to architecture around the world. From the mud huts of ancient history to today’s towering edifices, you can explore iconic buildings and find out more about the people who created them. You’ll also discover the development of different building materials, from mud and straw to paper, steel and reinforced concrete.
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Gran pla general aeri del Campus de Manresa a color amb el fons urbà i natural en banc i negre

UPCommons - dj., 02/28/2019 - 15:55
Gran pla general aeri del Campus de Manresa a color amb el fons urbà i natural en banc i negre
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Microwave and optical data fusion for global mapping of soil moisture at high resolution

UPCommons - dj., 02/28/2019 - 14:58
Microwave and optical data fusion for global mapping of soil moisture at high resolution Portal González, Gerard; Vall-Llossera Ferran, Mercedes Magdalena; Piles Guillem, Maria; Camps Carmona, Adriano José; Chaparro Danon, David; Pablos Hernánez, Miriam; Rossato, Luciana; Aabouch, Khalid After more than 8 years in orbit the Soil Moisture and Ocean Salinity (SMOS) satellite is still in good health and several algorithms for improving its spatial resolution have been proposed and validated in a variety of catchments. However, none of them has yet been applied at the global scale. In this article we present: i) a review of the latest SMOS-BEC downscaling algorithm, which allows for its global application using an adaptive moving window and ii) a thorough validation of the resulting maps over two in-situ networks: REMEDHUS in Spain and OzNet in Australia. The proposed algorithm combines SMOS brightness temperatures (at ~40 km spatial resolution), and MODIS-derived Land Surface Temperature and Normalized Differenced Vegetation Index (at 1 km), into 1km soil moisture maps. This paper also presents a variant of the algorithm, which allows for cloud-free retrievals. A statistical comparison has been carried out when the MODIS Land Surface Temperature is replaced in the algorithm by the one provided by the ERA5 reanalysis. Fine-scale estimates show good agreement in terms of correlation and root-mean-squared error with in-situ soil moisture.
Categories: Novetats

Definable ellipsoid method, sums-of-squares proofs, and the isomorphism problem

UPCommons - dj., 02/28/2019 - 14:53
Definable ellipsoid method, sums-of-squares proofs, and the isomorphism problem Atserias, Albert; Ochremiak, Joanna The ellipsoid method is an algorithm that solves the (weak) feasibility and linear optimization problems for convex sets by making oracle calls to their (weak) separation problem. We observe that the previously known method for showing that this reduction can be done in fixed-point logic with counting (FPC) for linear and semidefinite programs applies to any family of explicitly bounded convex sets. We use this observation to show that the exact feasibility problem for semidefinite programs is expressible in the infinitary version of FPC. As a corollary we get that, for the graph isomorphism problem, the Lasserre/Sums-of-Squares semidefinite programming hierarchy of relaxations collapses to the Sherali-Adams linear programming hierarchy, up to a small loss in the degree. © 2018 ACM.
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Matrix tree theorem for Schrödinger operators on networks

UPCommons - dj., 02/28/2019 - 14:49
Matrix tree theorem for Schrödinger operators on networks Carmona Mejías, Ángeles; Encinas Bachiller, Andrés Marcos; Mitjana Riera, Margarida
Categories: Novetats

Technology mapping for speed-independent circuits: Decomposition and resynthesis

UPCommons - dj., 02/28/2019 - 13:29
Technology mapping for speed-independent circuits: Decomposition and resynthesis Kondratyev, Alex; Cortadella, Jordi; Kishinevsky, Michael; Lavagno, Luciano; Yakovlev, Alex This paper presents theory and practical implementation of a method for multi-level logic synthesis of speed-independent circuits. An initial circuit implementation is assumed to satisfy the monotonous cover conditions but is technology independent. The proposed method performs both combinational (inserting new gates) and sequential (inserting new memory elements) decomposition of complex gates in a given standard cell library, while preserving original behaviour and speed-independence. The algorithm applies known efficient algebraic factorization techniques from combinational multi-level logic synthesis, but achieves also boolean simplification and sequential decomposition. The method allows sharing of decomposed logic.
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VR-assisted architectural design in a heritage site: the Sagrada Família case study

UPCommons - dj., 02/28/2019 - 13:12
VR-assisted architectural design in a heritage site: the Sagrada Família case study Andújar Gran, Carlos Antonio; Brunet Crossa, Pere; Buxareu, Jeronimo; Fons Sanchez, Joan; Laguarda, Narcis; Pascual, Jordi; Pelechano Gómez, Núria Virtual Reality (VR) simulations have long been proposed to allow users to explore both yet-to-built buildings in architectural design, and ancient, remote or disappeared buildings in cultural heritage. In this paper we describe an on-going VR project on an UNESCO World Heritage Site that simultaneously addresses both scenarios: supporting architects in the task of designing the remaining parts of a large unfinished building, and simulating existing parts that define the environment that new designs must conform to. The main challenge for the team of architects is to advance towards the project completion being faithful to the original Gaudí’s project, since many plans, drawings and plaster models were lost. We analyze the main requirements for collaborative architectural design in such a unique scenario, describe the main technical challenges, and discuss the lessons learned after one year of use of the system.
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Gestión de movimientos en suelo en el aeropuerto de Barcelona

UPCommons - dj., 02/28/2019 - 13:01
Gestión de movimientos en suelo en el aeropuerto de Barcelona Villegas Martín, Pablo Uno de los objetivos básicos en el transporte esla seguridad. Cuando se habla de sistemas de transporte con índices muy elevados de mortalidad en caso de accidente,como son los sistemas aéreos,se deben poner todas las atenciones preventivas necesarias y complementarias que reduzcan al mínimo la probabilidad de que ocurran.El propósito de este trabajo es incorporar una herramienta más, a todos los medios actualmente usados,que ayude al control y la seguridad en el transporte aéreo.En concreto, se pretende mejorar la seguridad en las maniobras de rodaje, conjunto de movimientos que la aeronave realiza en las carreterasde rodajedel aeropuerto.En la primera partedel trabajo se realiza una visión global del estado en el que se encuentra el aeropuerto de Barcelona,los sistemas actuales utilizados para el control de los aviones,así como numerosas definiciones útiles para la comprensión del trabajo. Posteriormente se explica el funcionamiento del sistemagenerado y se detallan los niveles de implementación.A modo de resumen, este sistema consiste en el control a tiempo real de la situación de todos los aviones que se encuentran en el aeropuerto, permitiendo así a los controladores dar las órdenes pertinentes o que de manera automática el avión reciba instrucciones. Se ha generado una interfaz gráfica capaz de absorber un sistema A-SMGCS de nivel 4.Finalmente, en el último capítulo,se confecciona un presupuesto que permitirá ver el coste de referencia parala implementación del sistema, así como los beneficios económicos que supone para los stakeholdersdel proyecto.
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Parlament del delegat del rector al CBL

UPCommons - dj., 02/28/2019 - 13:01
Parlament del delegat del rector al CBL
Categories: Novetats

Aplicació de tecnologia fotovoltaica low cost al circuit de Castellolí

UPCommons - dj., 02/28/2019 - 12:58
Aplicació de tecnologia fotovoltaica low cost al circuit de Castellolí Saiz Rabert, Albert El present projecte consta d’un estudi dela viabilitat tècnica/econòmica per la implementació de la tecnologia fotovoltaica per tal de realitzar un autoconsum que permeti desconnectar de la xarxa elcircuit Parcmotor de Castellolí. Les zones que disposa el circuit per instal·lar les lonesfotovoltaiques són: la coberta del magatzem,totalment plana,que té una superfície de 520 m2 , un talúsinclinada respecte l’horitzontal en 45º orientadaal sud que té una superfície útil aproximadament de 1200 m2i per últim una coberta semiesfèrica amb una superfície de 450 m2. Així doncs les 3 ubicacions sumen un total de 2.171 m2, que actualment estan del tot desaprofitades. Es té pensat utilitzar dos zones més del circuit per tal de poder ampliar la instal·lació fotovoltaica i ferfront a la previsió d’augment de la demanda energèticapel 2030. La tecnologia que s’utilitza en aquest estudi no és la més habitual que podem trobar en el mercatdel’autoconsum domèstico industrial. Entre les diferents tecnologiesexistentss’ha escollit latecnologia de capa fina, que la diferenciade la convencional perquè els mòduls fotovoltaics són flexibles, cosa que permet unaadaptació pràcticament total en aquelles cobertes que presentin curvatureso inclinacionsi del seu baix cost.No requereixen d’una estructura on recolzar els panells, sinó que van directament acoblats a la coberta, fetque abarateix el cost d’instal·lació i facilita el temps de la posada en marxa. També són més econòmics pel tipus de cèl·lula fotovoltaica emprada en aquests mòduls, ja que estan compostes de silici amorf (a-Si) i el seu procés de fabricació no precisa de tanta energia com les monocristal·lines o les policristal·lines. L’eficiència d’aquestes lones, de capa fina, solen rondar al 8%, mentre que amb cèl·lules mono o policristal·lines superen sense cap problema el 15%. Pel que fa el consum actual del Parcmotor, per una banda es subministra directament de la xarxa elèctrica, un 30% del seu consum total i la resta delconsum, el 70%, es fa a través de dos grups electrògensinstal·lats en el circuitque consumeixen combustible fòssil. A l’any anterior, el consum elèctric del circuit va ser aproximadamentde 131.000kWh/any.Amb les 3 regions esmentadesanteriorments’ha fet els pertinents càlculsi s’ha observat, que amb el producte escollit per aquest projecte, la potència fotovoltaica instal·lada és de 134,7 kWp, que surt un ràtio aproximat de 65Wp/m2, l’energia que es podria obtenir és de172.000 kWh/any. Sempre es tindrà com a font de reserva, en cas que fos necessari, el grup electrogen de 140 kW.Per últim, la vessant econòmica es veu fortament condicionada per la instal·lació de bateries. La part positiva d’aquest projecte, és que es podrà utilitzar unes bateries de segona vida a cost 0, proporcionades per una empresa d’automòbils, i per tant farà que el projecte sigui més atractiu obtinguen un TIR casi del 13%.
Categories: Novetats

Concurs d'habitatges al carrer Palamós 88, Bloc I de la UA3 de la Trinitat Nova

UPCommons - dc., 02/27/2019 - 19:37
Concurs d'habitatges al carrer Palamós 88, Bloc I de la UA3 de la Trinitat Nova Coll López, Jaime; Leclerc, Judith; Pagés Serra, Jorge; Bendicho Cabuti, Pasqual; Camallonga Rodriguez, Marc Institut Municipal de l'habitatge i Rehabilitació
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Cooperación: la Agencia Espacial Europea

UPCommons - dc., 02/27/2019 - 19:34
Cooperación: la Agencia Espacial Europea Barceló Garcia, Miquel
Categories: Novetats

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