http://www.recercat.cat:80/handle/2072/2245 Tue, 21 May 2013 14:50:43 GMT 2013-05-21T14:50:43Z http://www.recercat.cat:80/bitstream/id/35023/ http://www.recercat.cat:80/handle/2072/2245 http://www.recercat.cat:80/handle/2072/211446 Effects of non-toxic solvent microemulsion in washing wool Carrión Fité, Francisco Javier This work studies the detersive power and redeposition of impurities after washing standard wool fabrics with a non-toxic solvent microemulsion added to the conventional washing formulations in order improve the results of conventional washing. The solvent was dimethyl sulfoxide (DMS), emulsified and micro-dispersed with amphoteric surfactant. The fabric was washed using non-ionic surfactants, alcohol ethoxylate (AE-7) with 7 m. E.O. and an alkyl polyglucoside (APG). Detersive power was studied as function of those surfactants and their differing proportions in mixture. Detersive power was potentiated by addition sodium carbonate and sodium chloride as builders, and it was likewise studied under the influence of the salts with different water hardness used in the tests. A sequestering agent, DTPMP, was used to improve the results for detergency. The tensile strength and burst strength of the wool fabric washed with those surfactants and the microdispersed DMS with repeated washes was assessed. With those non-ionic surfactants used in the same programmed washing tests, the redeposition of a solid impurity, namely carbon black, during the washing was also studied, and a notable decrease of redeposition was attained with addition of the microemulsified DMS, which was also observed with the additional use of sodium dodecylbenzenesulfonate (LAS). In order to predict the stability of the particles of carbon black and the particles of DMS in the washing bath, the size of those particles was determined http://www.recercat.cat:80/handle/2072/211446 http://www.recercat.cat:80/handle/2072/211445 Washing wool with surfactants and a non-toxic solvent microemulsion: influence of water hardness Carrión Fité, Francisco Javier In this work, detersive power (soil removal) was studied after washing a soiled wool fabric with addition of a non-toxic solvent microemulsion to conventional washing detergent formulations with the aim of improving the performance of the conventional washing. The non-toxic solvent used was dimethyl sulfoxide micro-dispersed with an amphoteric surfactant as emulsifier. The fabric was washed with biodegradable non-ionic surfactants such as an alcohol ethoxylate (AE) with 7 mE.O. and an alkyl polyglucoside with 1.4 glucoside groups (APG). The fabric used was EMPA 107 wool (soiled with standard impurities). The non-ionic surfactants were used separately and in mixture in varying proportions for the washes. Given the large amount of impurities in the wool fabric, sodium carbonate and sodium chloride were used to attain a suitable pH to avoid damaging the wool. The fabric was washed at low temperature with water of different hardness (20º hf, 30º hf and 40º hf). In addition, the sequestering agent DTPMP was used to obtain an improvement of detersive power at the hardness of 40º hf http://www.recercat.cat:80/handle/2072/211445 http://www.recercat.cat:80/handle/2072/211444 FRA: A new fuzzy-based routing approach for optical transport networks Ahvar, E.; Marín Tordera, Eva; Yannuzzi, Marcelo; Masip Bruin, Xavier; Ahvar, S. Providing networks with QoS guarantees is one of the key issues to support current and future expected clients' demands. In this scenario, QoS routing is definitely critical as being responsible for defining those optimal routes supporting traffic forwarding throughout the whole network. This paper proposes two new QoS-aware RWA algorithms dealing with the routing inaccuracy problem, aiming at reducing blocking probability while limiting signaling overhead and balancing network load. The proposed algorithms extend the work already published by the authors on prediction based routing by adding a novel fuzzy-based technique featuring a powerful tool for modeling uncertainty. The proposed algorithms are compared with a well-known RWA algorithm and results show the benefit of introducing the fuzzy techniques in the RWA selection. http://www.recercat.cat:80/handle/2072/211444 http://www.recercat.cat:80/handle/2072/211443 Use of a Low-Mach model on a CFD&HT solver for the elements of an object oriented program to numerically simulate hermetic refrigeration compressors López Mas, Joan; Lehmkuhl Barba, Oriol; Rigola Serrano, Joaquim; Pérez Segarra, Carlos David A powerful object oriented approach for the simulation of generic thermal systems (Damle et al., 2008) is used as a framework to numerically simulate the thermal and fluid behavior of hermetic reciprocating compressors. A physical abstraction of the compressor system provides a vertex-edge graph, defining the elements and the neighborhood relations of the system to be solved. Each one of these resulting elements is modeled in order to be solved by itself by giving their respective boundary conditions. Since each element provides its own solver tool, the coupled system can be solved in an integrated form.Into previous works, an unstructured and parallel object oriented Computational Fluid Dynamics and Heat Transfer code (from now on CFD&HT) for accurate and reliable solving of turbulent industrial flow, called TermoFluids (Lehmkuhl et al., 2007), was used to provide with CFD&HT capability the system elements (López et al., 2010). In this work, a Low-Mach based CFD&HT module (Chiva et al., 2011) implemented within the TermoFluids software has been used solve the fluid domain existing inside the shell of a reciprocating compressor, which is identified as one of the compressor elements in the abstraction stage.This improvement allows us to numerically simulate the recirculation flow inside the shell of a reciprocating compressor, providing detailed information about suction area of the compressor and allowing study of new geometric configurations of such part. Furthermore, in comparison with previously tested CFD&HT modules, the Low-Mach model allows better treatment of the compressibility effects generated at the inner elements of the compressor such as chambers, tubes and undoubtedly the compression chamber. http://www.recercat.cat:80/handle/2072/211443 http://www.recercat.cat:80/handle/2072/211427 Leer y comprender la ciudad Franquesa Sànchez, Jordi Este artículo pretende poner de relieve y valorar cómo diferentes medodologías deaprendizaje implementadas en las aulas de taller pueden mejorar sensiblemente la capacidad de razonamiento crítico del alumno, aumentando así sus aptitudes para poder resolver determinados problemas que se le puedan presentar en la disciplina del urbanismo. http://www.recercat.cat:80/handle/2072/211427 http://www.recercat.cat:80/handle/2072/211428 Simulation of LTE IR H-ARQ at system level using MIESM error prediction Olmos Bonafé, Juan José; Serra, Albert; García Lozano, Mario; Ruiz Boqué, Sílvia; Pérez Díaz de Cerio, David http://www.recercat.cat:80/handle/2072/211428 http://www.recercat.cat:80/handle/2072/211426 Novel polycarbonate-graphene nanocomposite foams prepared by CO2 dissolution Gedler, Gabriel; Sousa Pais Antunes, Marcelo de; Redondo Realinho, Vera Cristina de; Velasco Perero, José Ignacio Polycarbonate foams reinforced with 0,5 wt% of graphene were obtained by firstly melt-mixing the polycarbonate and graphene in an internal mixer, compression-moulding the melt-compounded grinded material and lastly dissolving CO2 inside a high pressure vessel. The CO2 desorption behaviour in the unfilled polycarbonate and nanocomposite was studied in terms of the CO2 saturation concentration and desorption diffusion coefficient, with the graphene-filled nanocomposite displaying a higher CO2 loss rate when compared to the neat polycarbonate. The cellular structure of the foams was found to be highly dependent on the saturation/foaming temperature, with smaller cell sizes being obtained with decreasing the temperature. Another parameter that had an important influence was the residual pressure, with higher residual pressure values resulting in foams with more uniform and regular cells. http://www.recercat.cat:80/handle/2072/211426 http://www.recercat.cat:80/handle/2072/211425 Resonant pulse-shaping power supply for radar transmitters Bell Rodriguez, Miguel Victoria Ramo; Roberg, Michael; Pack, Riley; Garcia Fernandez, Pablo; Alarcón Cot, Eduardo José; Popoviç, Zoya; Maksimovic, Dragan The final radiofrequency power amplifier (PA) of a radar transmitter module is a large factor in system efficiency. Typical radar transmitter signals are frequency-modulated with constant-amplitude pulse envelopes in order to optimize efficiency, resulting in spectral broadening and power radiated outside of the radar frequency band. This paper demonstrates a PA with a dynamic power supply which enables high efficiency while reducing the spectral emissions. The resonant pulse-shaping power supply generates a raised-cosine pulse envelope waveform with efficiency greater than 90% and peak envelope power around 6 W. Measured results with a 2.14-GHz GaN power amplifier with an efficiency of 76% at peak power demonstrate over 67% transmitter efficiency. http://www.recercat.cat:80/handle/2072/211425 http://www.recercat.cat:80/handle/2072/211423 105143 Ruisánchez Capelastegui, Manuel Treball presentat al concurs: Realisierungswettbewerb "Neugesstaltung Ernst-AbbePlatz" http://www.recercat.cat:80/handle/2072/211423 http://www.recercat.cat:80/handle/2072/211424 Happy End Ruisánchez Capelastegui, Manuel Treball presentat al Concurs 16 portes de Collserola - Porta 13 Trinitat http://www.recercat.cat:80/handle/2072/211424 http://www.recercat.cat:80/handle/2072/211422 Secondary control for reactive power sharing in droop-controlled islanded microgrids Micallef, A.; Apap, Maurice; Spiteri Staines, C.; Guerrero Zapata, Josep Maria This paper focuses on the islanded operation of microgrids. In this mode of operation, the microsources are required to cooperate autonomously to regulate the local gridvoltage and frequency. Droop control is typically used to achieve this autonomous voltage and frequency regulation. However,droop control has real and reactive power sharing limitations when there are mismatches between the microsources. Thispaper analyses the effect due to mismatches in the power line impedances connecting the source inverters to the microgrid.From the simulations results obtained, it was shown that the reactive power demand is unequally shared between the microsource inverters when there are mismatches between the power line impedances. To achieve equal reactive power sharing between the inverters, an external loop requiring low bandwidth communications was implemented in a central controller.Simulation results are presented showing the feasibility of the proposed solution in achieving reactive power sharing betweenthe inverters connected to the microgrid. http://www.recercat.cat:80/handle/2072/211422 http://www.recercat.cat:80/handle/2072/211421 Focalization of evanescent beams Botey Cumella, Muriel; Cheng, Yu Chieh; Herrero Simon, Ramon; Romero García, V.; Pico, R.; Sánchez Morcillo, V. J.; Staliunas, Kestutis We predict and show the existence of unlocked evanescent waves in two dimensional periodic structures. In a one dimensional periodic structure an evanescent mode are located either at the center or at the boundary of the Brillouin Zone, and the real part of wave-vectors is locked either to zero or to the modulation vector of theperiodicity. However, we report an unexpected observation that this is not the case in 2D or 3D PhCs where "unlocked" complex modes can be predicted. As an interesting consequence, due to their “complex” character, or, equivalently, due to their phase freedom, beams constructed from such evanescent waves can show focalization effects. Indeed, we numerically simulate the propagation of such beams in the bandgap of PhC slabs,and we find significant focalization. http://www.recercat.cat:80/handle/2072/211421 http://www.recercat.cat:80/handle/2072/211420 Current control design for three-phase grid-connected inverters using a pole placement technique based on numerical models Citro, Costantino; Gavriluta, Catalin; Nizak Md, H. K.; Beltran, H. This paper presents a design procedure for linear current controllers of three-phase grid-connected inverters. The proposed method consists in deriving a numerical model of the converter by using software simulations and applying the poleplacement technique to design the controller with the desired performances. A clear example on how to apply the technique isprovided. The effectiveness of the proposed design procedure has been verified through the experimental results obtained witha 10kW grid-connected three-phase inverter prototype. http://www.recercat.cat:80/handle/2072/211420 http://www.recercat.cat:80/handle/2072/211419 A variational multiscale stabilized finite element method for the solution of the Euler equations of nonhydrostatic stratified flows Marras, Simone; Moragues, Margarida; Vázquez, Mariano; Jorba Casellas, Oriol; Houzeaux, Guillaume We present a compressible version of the variational multiscale stabilization (VMS) method applied to the finite element (FE) solution of the Euler equations for nonhydrostatic stratified flows. This paper is meant to verify how the algorithm performs when solving problems in the framework of nonhydrostatic atmospheric dynamics. This effort is justified by the previously observed good performance of VMS and by the advantages that a compact Galerkin formulation offers on massively parallel architectures – a paradigm for both computational fluid dynamics (CFD) and numerical weather prediction (NWP) practitioners. We also propose a simple technique to construct a well-balanced approximation of the dominant hydrostatics that, if not properly discretized, may cause unacceptable vertical oscillations. This is a relevant problem in NWP, especially in the proximity of steep topography. To evaluate the performance of the method for stratified environments, six standard 2D and two 3D test cases are selected. Of these, two admit a semi-analytic solution, while the remaining six are non-steady and non-linear thermal problems with dominant buoyancy effects that challenge the algorithm in terms of stability. http://www.recercat.cat:80/handle/2072/211419 http://www.recercat.cat:80/handle/2072/211418 Determining the thermal conductivity as a function of water content for a soil with different percentages of gravels Rubio Esteve, Carlos Miguel; Josa March, Ramon; Cobos, Douglas R.; Campbell, C.S.; Ferrer, Francesc http://www.recercat.cat:80/handle/2072/211418 http://www.recercat.cat:80/handle/2072/211417 Cooperative communications: from theory to experimental implementation Alonso-Zárate, Jesús; Sanchez Recacha, Javier; Zorba, Nizar; Pérez Neira, Ana Isabel; Verikoukis, Christos Over the last years, cooperative communications have been studied from both fundamental and practical points of view. However, most of the existing studies of cooperative communications rely on math or computer simulation. In this paper, we describe the implementation of a cooperative communication strategy for wireless networks in a testbed based on Click Modular Router. We describe the methodology we have followed to reprogram the drivers controlling the data layer functions of off-the-shelf commercial Wireless Network Interface Cards (NICs). More precisely, we have implemented a Cooperative Automatic Retransmission (C-ARQ) scheme to show that the performance of wireless communications can be boosted by using an intermediate relay when the wireless channel between the source and the destination is in bad conditions. The results presented in this paper are promising, as they show that previous theory and simulation results presented in the literature can become true in a real implementation. http://www.recercat.cat:80/handle/2072/211417 http://www.recercat.cat:80/handle/2072/211416 Sinopsis y notas de trabajo sobre autocad: inventario y propuestas Nogués Mañé, Carlos En los últimos años de docencia he venido redactando cortas monografías para poner en orden mispropias ideas y fijar conclusiones sobre el funcionamiento de AutoCAD en sus distintas versiones,porque los manuales suelen pasar de puntillas sobre las cuestiones espinosas. También los recorridostransversales, sobre los diferentes temas que afectan a una cuestión o su evolución a lo largo desucesivas versiones, son recomendables para contrarrestar la excesiva parcelación de las exposicionessistemáticas. De todo este material, sólo una parteha sido incluida en los apuntes de clase porque elresto es más bien letra pequeña sólo apta para especialistas, si bien podría ser útil su difusión aunquesólo fuera para evitar a sus potenciales lectores quemar muchas horas frente al ordenador: dado elmutismo o poca claridad de los manuales, la víaempírica es el único medio para alcanzar certezas.Como supongo que numerosos profesionales y docentes, con AutoCAD como herramienta habitual uobjeto de estudio, deben compartir tales inquietudes yhábitos, presento un inventario de las 30 fichasrealizadas hasta ahora, a disposición de cuantos acepten la filosofía del "quid pro quo". Incluyo lainvitación a colaborar, por puro placer, en el diseñode un simulador de reactivo posicional de cursor. ABSTRACT During the past few years, in view of the tendencyof manuals to pass quickly over difficult issues, Ihave written several short articles on the different versions of AutoCAD. Also, the excessive divisionsused in most systematic presentations mean that a lateral overview, looking at the different themes thataffect an issue or its evolutionthrough successive versions, is advisable and a welcome contrast. Fromall this material, only a small amount has been included in the class notes since the rest is really thesmall print which is only of interest to the expert. However, it could well be useful to publish it, if onlyto ensure that potential readers do not waste manyhours glued to their compared screens: in view ofthe lack of clarity in the manuals, experience is theonly way to arrive at certain results. As I supposethat many professionals and educators (who use AutoCAD as an everyday tool, or who study it) mustshare my concerns and methods, I am providing a list of the 30 files I have written so far. They areavailable to all those who accept the philosophy of "quid pro quo". I would also like to invite anyonewho is interested in collaborating, for the pure pleasure of it, in the design of a cursor position reactorsimulator. http://www.recercat.cat:80/handle/2072/211416 http://www.recercat.cat:80/handle/2072/211415 AutoCAD: adaptación de un bloque ortonormal 2d(3d) a un paralelogramo (paralelepípedo) dado Nogués Mañé, Carlos Si se ha tenido la precaución de referir a un bloque2D un cuadrado unitario ortogonal, será inmediatoinsertarlo de manera que éste se adapte a cualquiermarco rectangular establecido en el dibujo. Sinembargo, la inmediatez desaparece si pretendemos encadenar inserciones de manera que, además deuna combinación simple de escalado, giro y traslación, se halle implícita una transformación decortadura: cuando el marco receptor sea un paralelógramo oblicuo. Porque está claro que si insertamosel bloque girado, convertimos la inserción en bloque y volvemos a insertar, esta vez con escalado nouniforme, la figura transformada del primitivo cuadrado de referencia será un paralelógramo, pero elproblema es: dado un marco romboidal concreto, ¿con qué giro hay que realizar la primera inserción, yqué giro y factores de escala debemos aplicar a la segunda para que el cuadradode referencia se ciñaal marco? El problema se complica si queremos aprovechar el resultado de la primera inserción paraadaptaciones a otros paralelógramos, creando un sistema no redundante de inserciones intermedias,pero se ha diseñado un programa AutoLISP que resuelve estas cuestiones en 2D, en 3D y puede operarcon bloques con atributos, no sólo situados en elplano base sino ubicados y orientados libremente. ABSTRACTIf we reference an orthogonal unit square to a 2D-block, the block can immediately be inserted in such a way that the orthogonal unit square adapts toany existing rectangular frame in the drawing.However, this immediacy is lost if we wish to perform a series of insertions in such a way that, in addition to a simple combination of scaling, rotatingand translating, they implicitly include a shearingtransformation when the receiving frame is an obliqueparallelogram. This is because if we rotate theblock and then insert it, convert the insertion intoa block and reinsert (this time using a non-uniformscale factor), the figure resulting from this transformation of the original reference square will be aparallelogram. However, the question we wish totackle is the following. Given a specific rhomboidframe, exactly what rotation do we need when making the first insertion, and what rotation and scalefactors must we apply when inserting for the second time,in order to ensure that the reference squarefits the frame exactly? The problem becomes more complicated if we wish to use the result of the firstinsertion and adapt it for other parallelograms,creating a non-redundant system of intermediateinsertions. An AutoLISP program has been designed which solves these problems in 2D and in 3D.Furthermore, it can cope with blocks that do not sitsquarely on the flat base, but which are arbitrarilylocated and orientated. http://www.recercat.cat:80/handle/2072/211415 http://www.recercat.cat:80/handle/2072/211413 Licensing open spectrum systems Vázquez, Miguel Angel; Pérez Neira, Ana Isabel; Lagunas Hernandez, Miguel A. This paper studies how the spectrum regulation could change in the future open spectrum communication systems. Due to their huge success in short-range communication systems (WiFi, Zigbee, ...), broader area telecommunication providers might mimic the open spectrum philosophy to their systems. Nevertheless, current wireless open spectrum systems are not designed for wide areas and they do not provide QoS to their users. This work proposes an alternative to the nowadays open spectrum systems in order to fulfill those requirements. Optimal power transmission strategies are derived. Numerical results show the performance of our proposal. http://www.recercat.cat:80/handle/2072/211413 http://www.recercat.cat:80/handle/2072/211414 Odour mapping under strong backgrounds with a metal oxide sensor array Ziyatdinov, Andrey; Blanco Calvo, Jose Maria; Bermudez Badia, Sergi; Lechon, Miguel; Marco, Santiago; Verschure, Paul; Perera Lluna, Alexandre This text describes the data from an initial set of navigation experiments in the scope of the Bio-ICT European project NEUROCHEM (...) This poster shows that a preprocessing based on Independent Component Analysis is able to discriminate two odour sources. Further work will include automatic determination of the number of components present in the tunnel and the application of the Neurochem platform in surge-and-cast behavioral models. http://www.recercat.cat:80/handle/2072/211414 http://www.recercat.cat:80/handle/2072/211412 Optimal linear correction in LMMSE estimation using moments of the complex inverse Wishart distribution Serra, Jordi; Nájar Martón, Montserrat The conventional linear minimum mean square error esti-mator (LMMSE) suffers a severe performance degradationwhenever the sample size is comparable to the observationdimension. In order to tackle this problem, we propose anoptimal linear correction of the conventional LMMSE, whichminimizes the average mean square error (MSE) by usingthe moments of the complex inverse Wishart distribution.Numerical simulations highlight that the proposed estimatordramatically outperforms the conventional LMMSE in thesmall sample size regime http://www.recercat.cat:80/handle/2072/211412 http://www.recercat.cat:80/handle/2072/211411 CMOS fast transient low-dropout regulator Saberkari, Alireza; Alarcón Cot, Eduardo José; Shokouhi, Shahriar B. In this paper a fast transient response CFA-based low-dropout regulator (LDO) is introduced. The circuit is stable for 0-100mA output load current and a 1μF output capacitor without any internal compensation. The CFA consists of a voltage follower with output local current-current feedback based on a level-shifted flipped voltage follower (LSFVF) which is instrumental to achieve high regulation and fast transient response. The inverting output buffer stage of the CFA together with current-mirror-based driving of the pass transistor results in high PSRR. Full transistor-level simulation results for an AMS 0.35μm CMOS process design reveal that the proposed LDO dissipates 58μA quiescent current at no-load condition and in worst case conditions has a current efficiency of 99.8%. For a 1μF output capacitor, the maximum output voltage variation to a 0-100mA load transient with rise and fall time of 10 and 100ns is only 2.5mV, and the PSRR is smaller than -58dB over the entire load current range. http://www.recercat.cat:80/handle/2072/211411 http://www.recercat.cat:80/handle/2072/211410 Mathematical model of total cross-tied photovoltaic arrays in mismatching conditions Ramos Paja, Carlos Andres; Bastidas, Juan David; Saavedra Montes, Andres Julian; Guinjoan Gispert, Francisco; Goez, M. This paper presents a mathematical procedure for modeling rectangular (N rows with M modules each) and non-rectangular photovoltaic (PV) arrays in Total Cross-Tied (TCT) configuration operating in uniform and mismatching conditions. The proposed model uses the simple single diode representation for each PV module; then each row of the TCT array is represented as an equivalent non-linear PV circuit with a bypass diode, which allows to represent the TCT array as one string of equivalent PV circuits. The inflection voltages (array voltages that turn off the bypass diodes) of the string are calculated in order to solve only the non-linear equation system related to the active equivalent PV circuits for calculating the array current for a given voltage. Such a strategy reduces the computational burden and improves calculation speed. A TCT array of 4×2 with deep mismatching conditions was implemented in PSIM software to validate the proposed model, obtaining a correlation between model predicted data and the circuital simulation. The accuracy and improved calculation speed of the proposed model allow its use altogether with reconfiguration techniques as well as to reduce the time of energetic evaluations of TCT arrays for PV planning. http://www.recercat.cat:80/handle/2072/211410 http://www.recercat.cat:80/handle/2072/211408 An approximate algorithm for median graph computation using graph embedding Ferrer Sumsi, Miquel; Valveny, Ernest; Serratosa Casanelles, Francesc; Riesen, Kaspar; Bunke, Horst Graphs are powerful data structures that have many attractive properties for object representation. However, some basic operations are difficult to define and implement, for instance, how to obtain a representative of a set of graphs. The median graph has been defined for that purpose, but existing algorithms are computationally complex and have a very limited applicability. In this paper we propose a new approach for the computation of the median graph based on graph embedding in vector spaces. Experiments on a real database containing large graphs show that we succeed to compute good approximations of the median graph. We have also applied the median graph to perform some basic classification tasks achieving reasonable good results. http://www.recercat.cat:80/handle/2072/211408 http://www.recercat.cat:80/handle/2072/211409 Real time 100 GHz MST imaging retina Alonso Del Pino, Maria; Garg, V.; Garcia Guerra, Carlos Enrique; Romeu Robert, Jordi; Llombart, Nuria; Jofre Roca, Lluís A real time tomographic imaging system at 100 GHz based on a retina and Modulated Scattered Technique (MST) is presented in this paper. It consists in applying a low frequency modulation to each probe of an array of antennas in order to coherently detect the electric field by a collector. This system just requires low frequency wiring and reduces the RF equipment necessary for each pixel for a planar surface. The aim of this paper is to analyze the performance of different tomographic imaging processes for the imaging system described. http://www.recercat.cat:80/handle/2072/211409 http://www.recercat.cat:80/handle/2072/211407 On the design of a UAS flight plan monitoring and edition system Pastor Llorens, Enric; Santamaria Barnadas, Eduard; Royo Chic, Pablo; López Rubio, Juan; Barrado Muxí, Cristina This paper addresses various aspects of the design and development of the pilot interface for the exploitation of highly advanced flight plan capabilities specifically designed for Unmanned Aerial Systems (UAS). This flight plan capabilities are built on top a flexible and reusable hardware/software architecture designed to facilitate the development of UAS-based applications. This flexibility is organized into an user-parameterizable UAS Service Abstraction Layer (USAL). The USAL defines a collection of standard services are their interrelations as a basic starting point for further development by UAS users. Previous research presented the advanced flying capabilities of a UAS as an extension of the Flight Control System (FCS) functionalities. Assuming a UAS with a FCS that ensures safe and stable maneuvers, we complement it with a highly capable flight plan management system. USAL flight plan is characterized by offering semantically much richer constructs than those present in most current UAS autopilots, which rely on simple lists of waypoints. This list of waypoints approach has several important limitations: it is difficult to specify complex trajectories and it does not support constructs such as conditional forks or iterations, small changes may imply having to deal with a considerable amount of waypoints and it provides no mechanism for adapting to mission time circumstances. To address these issues a new flight plan specification mechanism is proposed, that incorporates a leg concept extended to accommodate higher level constructs for specifying iterations and forks. Additional leg types, referred to as parametric leg, are also introduced. The trajectory defined by a parametric leg is automatically generated as a function of mission variables, enabling dynamic behavior and providing a very valuable means for adapting the flight to the mission evolution. Another level of adaption is provided by the conditions governing the decision-making in intersection le- - gs and the finalization of iterative legs. In this work we will focus on the development of the pilot interface for the exploitation of the introduced flight plan capabilities. The interface design requirements address an increase level of automated operation and support to react to unexpected requirements due to mission changes. Therefore, this interaction includes the available mechanisms to update the flight-plan according to UAS mission requirements, skip parts of it, react to operational contingencies, etc. http://www.recercat.cat:80/handle/2072/211407 http://www.recercat.cat:80/handle/2072/211406 An iterative algorithm for approximate median graph computation Ferrer Sumsi, Miquel; Bunke, Horst Recently, the median graph has been shown to be a good choice to obtain a representative of a given set of graphs. It has been successfully applied to graph-based classification and clustering. In this paper we exploit a theoretical property of the median, which has not yet been utilized in the past, to derive a new iterative algorithm for approximate median graph computation. Experiments done using five different graph databases show that the proposed approach yields, in four out of these five datasets, better medians than two of the previous existing methods. http://www.recercat.cat:80/handle/2072/211406 http://www.recercat.cat:80/handle/2072/211405 Combination of OCR engines for page segmentation based on performance evaluation Ferrer Sumsi, Miquel; Valveny, Ernest In this paper we present a method to improve the performance of individual page segmentation engines based on the combination of the output of several engines. The rules of combination are designed after analyzing the results of each individual method. This analysis is performed using a performance evaluation framework that aims at characterizing each method according to its strengths and weaknesses rather than computing a single performance measure telling which is the "best" segmentation method. http://www.recercat.cat:80/handle/2072/211405 http://www.recercat.cat:80/handle/2072/211404 Segmentation robust to the vignette effect for machine vision systems Karatzas, D; Rusiñol, Marçal; Antens, Coen; Ferrer Sumsi, Miquel The vignette effect (radial fall-off) is commonly encountered in images obtained through certain image acquisition setups and can seriously hinder automatic analysis processes. In this paper we present a fast and efficient method for dealing with vignetting in the context of object segmentation in an existing industrial inspection setup. The vignette effect is modelled here as a circular, non-linear gradient. The method estimates the gradient parameters and employs them to perform segmentation. Segmentation results on a variety of images indicate that the presented method is able to successfully tackle the vignette effect. http://www.recercat.cat:80/handle/2072/211404 http://www.recercat.cat:80/handle/2072/211403 ONU optimal gain and position of the distribution element in Rayleigh-limited WDM and TDM PONs with reflective ONU López Pastor, Eduardo Tommy; Lázaro Villa, José Antonio; Arellano Pinilla, Cristina; Polo Querol, Víctor; Prat Gomà, Josep Joan The influence of the distribution element position in PONs is reported. Best Crosstalk-to-Signal ratio (C/S) is achieved if it is placed either in the ONU or OLT vicinity with optimum ONU gain depending of the MUX position http://www.recercat.cat:80/handle/2072/211403