25 research outputs found

    Recent Advances in Robust Control

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    Robust control has been a topic of active research in the last three decades culminating in H_2/H_\infty and \mu design methods followed by research on parametric robustness, initially motivated by Kharitonov's theorem, the extension to non-linear time delay systems, and other more recent methods. The two volumes of Recent Advances in Robust Control give a selective overview of recent theoretical developments and present selected application examples. The volumes comprise 39 contributions covering various theoretical aspects as well as different application areas. The first volume covers selected problems in the theory of robust control and its application to robotic and electromechanical systems. The second volume is dedicated to special topics in robust control and problem specific solutions. Recent Advances in Robust Control will be a valuable reference for those interested in the recent theoretical advances and for researchers working in the broad field of robotics and mechatronics

    peak picking und map alignment

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    We study two fundamental processing steps in mass spectrometric data analysis from a theoretical and practical point of view. For the detection and extraction of mass spectral peaks we developed an efficient peak picking algorithm that is independent of the underlying machine or ionization method, and is able to resolve highly convoluted and asymmetric signals. The method uses the multiscale nature of spectrometric data by first detecting the mass peaks in the wavelet-transformed signal before a given asymmetric peak function is fitted to the raw data. In two optional stages, highly overlapping peaks can be separated or all peak parameters can be further improved using techniques from nonlinear optimization. In contrast to currently established techniques, our algorithm is able to separate overlapping peaks of multiply charged peptides in LC-ESI-MS data of low resolution. Furthermore, applied to high-quality MALDI-TOF spectra it yields a high degree of accuracy and precision and compares very favorably with the algorithms supplied by the vendor of the mass spectrometers. On the high-resolution MALDI spectra as well as on the low-resolution LC-MS data set, our algorithm achieves a fast runtime of only a few seconds. Another important processing step that can be found in every typical protocol for labelfree quantification is the combination of results from multiple LC-MS experiments to improve confidence in the obtained measurements or to compare results from different samples. To do so, a multiple alignment of the LC-MS maps needs to be estimated. The alignment has to correct for variations in mass and elution time which are present in all mass spectrometry experiments. For the first time we formally define the multiple LC-MS raw and feature map alignment problem using our own distance function for LC-MS maps. Furthermore, we present a solution to this problem. Our novel algorithm aligns LC-MS samples and matches corresponding ion species across samples. In a first step, it uses an adapted pose clustering approach to efficiently superimpose raw maps as well as feature maps. This is done in a star-wise manner, where the elements of all maps are transformed onto the coordinate system of a reference map. To detect and combine corresponding features in multiple feature maps into a so-called consensus map, we developed an additional step based on techniques from computational geometry. We show that our alignment approach is fast and reliable as compared to five other alignment approaches. Furthermore, we prove its robustness in the presence of noise and its ability to accurately align samples with only few common ion species.Im Rahmen dieser Arbeit beschäftigen wir uns mit peak picking und map alignment; zwei fundamentalen Prozessierungsschritten bei der Analyse massenspektrometrischer Signale. Im Gegensatz zu vielen anderen peak picking Ansätzen haben wir einen Algorithmus entwickelt, der alle relevanten Informationen aus den massenspektrometrischen Peaks extrahiert und unabhängig von der analytischen Fragestellung und dem MS Instrument ist. Im ersten Teil dieser Arbeit stellen wir diesen generischen peak picking Algorithmus vor. Für die Detektion der Peaks nutzen wir die Multiskalen-Natur von MS Messungen und erlauben mit einem Wavelet-basierten Ansatz auch das Prozessieren von stark verrauschten und Baseline-behafteten Massenspektren. Neben der exakten m/z Position und dem FWHM Wert eines Peaks werden seine maximale Intensität sowie seine Gesamtintensität bestimmt. Mithilfe des Fits einer analytischen Peakfunktion extrahieren wir außerdem zusätzliche Informationen über die Peakform. Zwei weiterere optionale Schritte ermöglichen zum einen die Trennung stark überlappender Peaks sowie die Optimierung der berechneten Peakparameter. Anhand eines niedrig aufgelösten LC-ESI-MS Datensatzes sowie eines hoch aufgelösten MALDI-MS Datensatzes zeigen wir die Effizienz unseres generischen Algorithmus sowie seine schnelle Laufzeit im Vergleich mit kommerziellen peak picking Algorithmen. Ein direkter quantitativer Vergleich mehrer LC-MS Messungen setzt voraus, dass Signale des gleichen Peptids innerhalb unterschiedlicher Maps die gleichen RT und m/z Positionen besitzen. Aufgrund experimenteller Unsicherheiten sind beide Dimension verzerrt. Unabhängig vom Prozessierungsstand der LC-MS Maps müssen die Verzerrungen vor einem Vergleich der Maps korrigiert werden. Mithilfe eines eigens entwickelten Ähnlichkeitsmaßes für LC-MS Maps entwickeln wir die erste formale Definition des multiplen LC-MS Roh- und Featuremap Alignment Problems. Weiterhin stellen wir unseren geometrischen Ansatz zur Lösung des Problems vor. Durch die Betrachtung der LC-MS Maps als zwei-dimensionale Punktmengen ist unser Algorithmus unabhängig vom Prozessierungsgrad der Maps. Wir verfolgen einen sternförmigen Alignmentansatz, bei dem alle Maps auf eine Referenzmap abgebildet werden. Die Überlagerung der Maps erfolgt hierbei mithilfe eines pose clustering basierten Algorithmus. Diese Überlagerung der Maps löst bereits das Rohmap Alignment Problem. Zur Lösung des multiplen Featuremap Alignment Problems implementieren wir einen zusätzlichen, effizienten Gruppierungsschritt, der zusammengehörige Peptidsignale in unterschiedlichen Maps einander zuordnet. Wir zeigen die Effizienz und Robustheit unseres Ansatzes auf zwei realen sowie auf drei künstlichen Datensätzen. Wir vergleichen hierbei die Güte sowie die Laufzeit unseres Algorithmus mit fünf weiteren frei verfügbaren Featuremap-Alignmentmethoden. In allen Experimenten überzeugte unser Algorithmus mit einer schnellen Laufzeit und den besten recall Werten

    Proceedings of the ECCOMAS Thematic Conference on Multibody Dynamics 2015

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    This volume contains the full papers accepted for presentation at the ECCOMAS Thematic Conference on Multibody Dynamics 2015 held in the Barcelona School of Industrial Engineering, Universitat Politècnica de Catalunya, on June 29 - July 2, 2015. The ECCOMAS Thematic Conference on Multibody Dynamics is an international meeting held once every two years in a European country. Continuing the very successful series of past conferences that have been organized in Lisbon (2003), Madrid (2005), Milan (2007), Warsaw (2009), Brussels (2011) and Zagreb (2013); this edition will once again serve as a meeting point for the international researchers, scientists and experts from academia, research laboratories and industry working in the area of multibody dynamics. Applications are related to many fields of contemporary engineering, such as vehicle and railway systems, aeronautical and space vehicles, robotic manipulators, mechatronic and autonomous systems, smart structures, biomechanical systems and nanotechnologies. The topics of the conference include, but are not restricted to: ● Formulations and Numerical Methods ● Efficient Methods and Real-Time Applications ● Flexible Multibody Dynamics ● Contact Dynamics and Constraints ● Multiphysics and Coupled Problems ● Control and Optimization ● Software Development and Computer Technology ● Aerospace and Maritime Applications ● Biomechanics ● Railroad Vehicle Dynamics ● Road Vehicle Dynamics ● Robotics ● Benchmark ProblemsPostprint (published version

    Multibody dynamics 2015

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    This volume contains the full papers accepted for presentation at the ECCOMAS Thematic Conference on Multibody Dynamics 2015 held in the Barcelona School of Industrial Engineering, Universitat Politècnica de Catalunya, on June 29 - July 2, 2015. The ECCOMAS Thematic Conference on Multibody Dynamics is an international meeting held once every two years in a European country. Continuing the very successful series of past conferences that have been organized in Lisbon (2003), Madrid (2005), Milan (2007), Warsaw (2009), Brussels (2011) and Zagreb (2013); this edition will once again serve as a meeting point for the international researchers, scientists and experts from academia, research laboratories and industry working in the area of multibody dynamics. Applications are related to many fields of contemporary engineering, such as vehicle and railway systems, aeronautical and space vehicles, robotic manipulators, mechatronic and autonomous systems, smart structures, biomechanical systems and nanotechnologies. The topics of the conference include, but are not restricted to: Formulations and Numerical Methods, Efficient Methods and Real-Time Applications, Flexible Multibody Dynamics, Contact Dynamics and Constraints, Multiphysics and Coupled Problems, Control and Optimization, Software Development and Computer Technology, Aerospace and Maritime Applications, Biomechanics, Railroad Vehicle Dynamics, Road Vehicle Dynamics, Robotics, Benchmark Problems. The conference is organized by the Department of Mechanical Engineering of the Universitat Politècnica de Catalunya (UPC) in Barcelona. The organizers would like to thank the authors for submitting their contributions, the keynote lecturers for accepting the invitation and for the quality of their talks, the awards and scientific committees for their support to the organization of the conference, and finally the topic organizers for reviewing all extended abstracts and selecting the awards nominees.Postprint (published version

    Effects of cholinesterase inhibition on brain function

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    Pharmacological-functional imaging provides a non-invasive method by which the actions of neurotropic drugs on the human brain can be explored. Simply put, it assesses how neural activity patterns associated with cognitive functions of interest are modified by a drug challenge. Since one of the most widely-used cognitive-enhancing drugs in clinical practice are cholinesterase inhibitors, this thesis applies pharmacological functional imaging to the question of understanding how such drugs work - both in healthy people and dementia. The experiments in this thesis describe how brain activations – as revealed by functional magnetic resonance imaging (fMRI) – are modulated by the cholinesterase inhibitor physostigmine, during tasks designed to isolate sensory, attentional, and memory processes. While non-human and human psychophysical studies suggest that all three of these cognitive functions are under the control of the endogenous cortical cholinergic system, understanding how neurobiological models of cholinergic function translate into human brain activation modulations is unclear. One main question that is particularly relevant in this regard, that recurs through all the experiments, is how physostigmine-induced neuromodulations differ between sensory-driven ‘bottom-up’, and task-driven ‘top-down’, brain activations. The results are discussed with reference both to non-human physiological data and to existing human cholinergic-functional imaging studies (fifty studies published to date), which are themselves reviewed at the outset. Furthermore, assumptions based upon the physical and physiological principles of pharmacological functional imaging, being critical to interpretation, are discussed in detail within a general methods section

    Modeling EMI Resulting from a Signal Via Transition Through Power/Ground Layers

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    Signal transitioning through layers on vias are very common in multi-layer printed circuit board (PCB) design. For a signal via transitioning through the internal power and ground planes, the return current must switch from one reference plane to another reference plane. The discontinuity of the return current at the via excites the power and ground planes, and results in noise on the power bus that can lead to signal integrity, as well as EMI problems. Numerical methods, such as the finite-difference time-domain (FDTD), Moment of Methods (MoM), and partial element equivalent circuit (PEEC) method, were employed herein to study this problem. The modeled results are supported by measurements. In addition, a common EMI mitigation approach of adding a decoupling capacitor was investigated with the FDTD method

    Tools and Algorithms for the Construction and Analysis of Systems

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    This open access book constitutes the proceedings of the 28th International Conference on Tools and Algorithms for the Construction and Analysis of Systems, TACAS 2022, which was held during April 2-7, 2022, in Munich, Germany, as part of the European Joint Conferences on Theory and Practice of Software, ETAPS 2022. The 46 full papers and 4 short papers presented in this volume were carefully reviewed and selected from 159 submissions. The proceedings also contain 16 tool papers of the affiliated competition SV-Comp and 1 paper consisting of the competition report. TACAS is a forum for researchers, developers, and users interested in rigorously based tools and algorithms for the construction and analysis of systems. The conference aims to bridge the gaps between different communities with this common interest and to support them in their quest to improve the utility, reliability, exibility, and efficiency of tools and algorithms for building computer-controlled systems

    Tools and Algorithms for the Construction and Analysis of Systems

    Get PDF
    This open access book constitutes the proceedings of the 28th International Conference on Tools and Algorithms for the Construction and Analysis of Systems, TACAS 2022, which was held during April 2-7, 2022, in Munich, Germany, as part of the European Joint Conferences on Theory and Practice of Software, ETAPS 2022. The 46 full papers and 4 short papers presented in this volume were carefully reviewed and selected from 159 submissions. The proceedings also contain 16 tool papers of the affiliated competition SV-Comp and 1 paper consisting of the competition report. TACAS is a forum for researchers, developers, and users interested in rigorously based tools and algorithms for the construction and analysis of systems. The conference aims to bridge the gaps between different communities with this common interest and to support them in their quest to improve the utility, reliability, exibility, and efficiency of tools and algorithms for building computer-controlled systems

    Performance analysis for wireless G (IEEE 802.11G) and wireless N (IEEE 802.11N) in outdoor environment

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    This paper described an analysis the different capabilities and limitation of both IEEE technologies that has been utilized for data transmission directed to mobile device. In this work, we have compared an IEEE 802.11/g/n outdoor environment to know what technology is better. The comparison consider on coverage area (mobility), throughput and measuring the interferences. The work presented here is to help the researchers to select the best technology depending of their deploying case, and investigate the best variant for outdoor. The tool used is Iperf software which is to measure the data transmission performance of IEEE 802.11n and IEEE 802.11g
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