73 research outputs found
Untersuchung von ausbringungspezifischer Simulation zur Optimierung drahtloser Sensornetzwerke
No full textThis theses researches whether it is possible to map existing deployments to a simulator accurately enough to use simulation to optimize for this specific deployment.
For this purpose DrySim was developed as an approach to achieve more realistic simulation of Wireless Sensor Networks (WSNs). DrySim has two components, RealSim and DryRun: RealSim traces the network connectivity of a deployed WSN and allows replaying it in a simulator, whereas DryRun supports exploring a configuration space by running simulations and extracting and preparing data for further analysis.
Two different test beds located in office environments were used to evaluate and verify the approach. Measurements in the two test beds showed that they required different configuration options. This was reflected in simulation as well as trial results.
The evaluation presents a solid data basis for three scenarios, with a total of 1320 test bed and 8800 simulation runs between 5 and 20 minutes. During the evaluation care was taken to avoid systematic or probe effects. Analysis of the test beds also revealed that the default settings of ContikiOS, a popular WSN operating system, are unsuitable for most WSN deployments.
The theses also features an analysis of the impact of different components on a WSN node. Specifically it was evaluated how accurately they can and must be simulated to achieve realistic results. These studies revealed two important points: Firstly the micro controller must be emulated to achieve real time accuracy. Secondly the radio characteristics of a network cannot be predicted and thus must be measured in the final deployment.
In previous work, only specific aspects of simulating WSNs were researched. The research done in the context of DrySim, however, shows that to achieve realistic WSN simulation the main components, which are software, micro controller and radio chip and the radio network, must not be treated separately.
With DrySim a solution is presented that allows for realistic enough simulation to tune configuration parameters to a specific deployment, while keeping the effort of tweaking the simulation model at a minimum.Diese Arbeit untersucht, ob es möglich ist bestehendes Sensornetzwerk in einem Simulator abzubilden, so dass dieses auf im Simulator ausbringungspezifisch optimiert werden kann.
Hierzu wurde DrySim entwickelt. Ein Ansatz um eine realistischere Simulation von drahtlosen Sensornetzwerken (WSN) zu erzielen. DrySim besteht aus zwei Komponenten, RealSim und DryRun: RealSim zeichnet die Netzwerkkonnektivität eines ausgebrachten WSN auf und kann diese im einem Simulator wiedergeben. DryRun hingeben kann durch die Ausführung von Simulationen einen Konfigurationsraum erkunden und die gewonnenen Daten aufbereiten.
Der Ansatz wurde in zwei Testnetzwerke, die in Büroräumen ausgebracht waren evaluiert. Die Messungen in den beiden Netzwerken haben gezeigt, dass sie unterschiedliche Konfigurationen benötigen, was sich auch in den Simulationen widergespiegelt hat.
Die Evaluation präsentiert eine solide Datenbasis für drei Szenarien, mit 1320 Versuchen auf den Testnetzwerken und 8800 Simulationen zwischen 5 und 20 Minuten. Es wurde darauf geachtet den Einfluss durch systematische Fehler und die Beobachtung zu vermeiden. Die Untersuchung hat auch gezeigt, dass die Standardeinstellungen von ContikiOS, eines verbreiteten WSN-Betriebssystems für die meisten Umgebungen ungeeignet sind.
Die Arbeit analysiert auch den Einfluss der verschiedenen Komponenten auf einen WSN-Knoten. Insbesondere wurde untersucht, wie akkurat diese simuliert werden können und müssen um realistische Simulationsergebnisse zu erzielen. Hierbei wurden zwei wichtige Punkte herausgearbeitet: Erstens muss der Mikrocontroller emuliert werden, um Echtzeitgenauigkeit zu erreichen. Zweitens können die Funkcharakteristiken eines Netzwerks nicht vorhergesagt werden und müssen daher vermessen werden.
Vorhergehenden Arbeiten haben sich meist auf spezifische Aspekte der Simulation von Sensornetzwerken konzentriert. Die in Kontext von DrySim betriebene Forschung zeigt jedoch, dass realistische Simulationsergebnisse nur erreicht werden können, wenn die Hauptkomponenten, Software, Mikrocontroller, Radio-Chip und Funknetzwerk nicht getrennt betrachtet werden.
Mit DrySim wird eine Lösung präsentiert, die es erlaubt bestehende Netzwerke so akkurat zu simulieren, dass man die Konfigurationsparameter auf dieses spezifische Netzwerk anpassen kann. Dabei bleibt der Konfigurationsaufwand bei einem Minimum
Adaptive compensation of measurement delays in multi-sensor fusion for inertial motion tracking using moving horizon estimation
No full textRobust and accurate pose estimation of moving systems is a challenging task that is often tackled by combining information from different sensor subsystems in a multi-sensor fusion setup. To obtain robust and accurate estimates, it is crucial to respect the exact time of each measurement. Data fusion is additionally challenged when the sensors are running at different rates and the information is subject to processing- and transmission delays. In this paper, we present an optimization-based moving horizon estimator which allows to estimate and compensate for time-varying measurement delays without the need for any synchronization signals between the sensors. By adopting a direct collocation approach, we find a continuous-time solution for the navigation states which allows us to incorporate the discrete-time sensor measurements in an optimal way despite the presence of unknown time delays. The presented sensor fusion algorithm is applied to the problem of pose estimation by fusing data of a high-rate inertial measurement unit and a low-rate centimeter-accurate global navigation satellite system receiver using simulated and real-data experiments.Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Team Jan-Willem van Wingerde
Should the EU implement a minimum corporate taxation directive?
No full textThe century old international tax system is in the middle of being rebuilt. Between the hope for a compromise and the fear of a tax war breaking out, this article inquires whether the EU should implement a minimum corporate taxation directive along the lines of the OECD GLOBE proposal. This question has legal and political dimensions. On the one hand, Art. 115 TFEU, which would be the basis for such a directive, demands an EU minimum taxation regime to promote the Internal Market. The article suggests that this may succeed. On the other hand, Art. 115 TFEU requires unanimity in the Council. Thus, and given the heterogeneity of Member States’ interests, additional tax policy reasons favouring such a directive are needed. Considering expectable reactions of taxpayers in a competitive environment and taking account of potential developments outside the EU, the author concludes that, overall, the implementation of an EU minimum taxation regime may – especially as a safeguard of origin based taxation – benefit the EU and all of its Member States. With the credible enforceability of minimum taxation rules being key, the author suggests EU action to establish minimum corporate taxation even if all EU Members States support the OECD proposal.
Date and Place21. April 2021; Espoo, FinlandAcknowledgementsThe author thanks Marjaana Helminen, Dennis Weber, Jan Klabbers, Karine Caunes, Noora Mäki, and Linda Sydänmaanlakka and two unknown peer-reviewers for discussing a draft version of the article and giving invaluable comments. The author thanks Suomen veromiehet - Finlands beskattningsmän ry for their financialsupport
Temporal navigation in hierarchically structured media
No full textThe process of creating large documents like a computer program, a book, or a movie can take several years. During this process the author may want to return to earlier versions of the document in order to compare different iterations or to undo an earlier change. Navigating in the evolution of a document is usually a tedious process because exiting tools typically consider the history of a document as a whole. The user's navigation goals, however, are focused around a specific change from only a part of the document. We compare the navigation of document versions to video navigation, where we see interfaces that enable users to find a specific frame based on an object's location in the video.Unfortunately, these interfaces restrict which frames are accessible to those frames where an object moves. It is also difficult to directly translate these interfaces to non-video media media because they require a static frame of reference which does not typically exist in other media types. We discuss extensions of these video navigation interfaces that lift some, but not all, of the restrictions. We then go on to propose an alternative approach based on a document's changing structure. Because such a structure changes slowly over time, we can base temporal navigation around this structure as a reference point. We discuss the principles of strcutrue in temporal navigation interfaces and propose an approach to visualize and interact with hierarchical structures over time. We introduce a system for source code history navigation based on the soruce code's hierarchical structure. Users perform navigation tasks twice as fast using structure aware interfaces compared to existing similar interfaces. They also strongly prefer our visualization when it comes to exploration tasks. Finally, we discuss how to extend this approach to other media types and non-hierarchical structures
Temporal navigation in hierarchically structured media
No full textThe process of creating large documents like a computer program, a book, or a movie can take several years. During this process the author may want to return to earlier versions of the document in order to compare different iterations or to undo an earlier change. Navigating in the evolution of a document is usually a tedious process because exiting tools typically consider the history of a document as a whole. The user's navigation goals, however, are focused around a specific change from only a part of the document. We compare the navigation of document versions to video navigation, where we see interfaces that enable users to find a specific frame based on an object's location in the video.Unfortunately, these interfaces restrict which frames are accessible to those frames where an object moves. It is also difficult to directly translate these interfaces to non-video media media because they require a static frame of reference which does not typically exist in other media types. We discuss extensions of these video navigation interfaces that lift some, but not all, of the restrictions. We then go on to propose an alternative approach based on a document's changing structure. Because such a structure changes slowly over time, we can base temporal navigation around this structure as a reference point. We discuss the principles of strcutrue in temporal navigation interfaces and propose an approach to visualize and interact with hierarchical structures over time. We introduce a system for source code history navigation based on the soruce code's hierarchical structure. Users perform navigation tasks twice as fast using structure aware interfaces compared to existing similar interfaces. They also strongly prefer our visualization when it comes to exploration tasks. Finally, we discuss how to extend this approach to other media types and non-hierarchical structures
Crown prince Rudolf and the Reform of the Habsburg Monarchy
No full textThe aim of this bachelor thesis is an analysis of Crown Prince Rudolf's opinions as reflected in his original texts, primarily in his newspaper articles, which were published anonymously. The author focuses on texts written about three main topics: Austrian nobility, Rudolf's attitude towards the many nations living within the Habsburg monarchy and the functionality of dualism or the possibility of a different form of government. The author has used the following methods to explore these topics: analysis of newspaper articles, other original texts and analysis of correspondence with fellow journalist Moritz Szeps as well as literature search. The thesis presents the situation in the Austro-Hungarian monarchy in the 1870s and 1880s and describes Rudolf's position on the issue of nationalism in a multi-ethnic monarchy, his views concerning the Balkan question, religious tolerance and the Jewish question. The Crown Princes' opinion on dualism and its disadvantages compared to a unified empire, his attitude towards the possibility of further splitting of the monarchy or its federalization, and his opinion on the possibility of the monarchy's dissolution are also presented. Rudolf's asessment of the morals of the blue-blooded and their attitude towards science and progress are also analysed. Both the..
Genetic association study of QT interval highlights role for calcium signaling pathways in myocardial repolarization.
No full textThe QT interval, an electrocardiographic measure reflecting myocardial repolarization, is a heritable trait. QT prolongation is a risk factor for ventricular arrhythmias and sudden cardiac death (SCD) and could indicate the presence of the potentially lethal mendelian long-QT syndrome (LQTS). Using a genome-wide association and replication study in up to 100,000 individuals, we identified 35 common variant loci associated with QT interval that collectively explain ∼8-10% of QT-interval variation and highlight the importance of calcium regulation in myocardial repolarization. Rare variant analysis of 6 new QT interval-associated loci in 298 unrelated probands with LQTS identified coding variants not found in controls but of uncertain causality and therefore requiring validation. Several newly identified loci encode proteins that physically interact with other recognized repolarization proteins. Our integration of common variant association, expression and orthogonal protein-protein interaction screens provides new insights into cardiac electrophysiology and identifies new candidate genes for ventricular arrhythmias, LQTS and SCD
Research in medical education - chances and challenges : international conference, 20th - 22nd May 2009, Heidelberg ; congress abstracts
No full textHundreds of variants clustered in genomic loci and biological pathways affect human height
No full textMost common human traits and diseases have a polygenic pattern of inheritance: DNA sequence variants at many genetic loci influence the phenotype. Genome-wide association (GWA) studies have identified more than 600 variants associated with human traits(1), but these typically explain small fractions of phenotypic variation, raising questions about the use of further studies. Here, using 183,727 individuals, we show that hundreds of genetic variants, in at least 180 loci, influence adult height, a highly heritable and classic polygenic trait(2,3). The large number of loci reveals patterns with important implications for genetic studies of common human diseases and traits. First, the 180 loci are not random, but instead are enriched for genes that are connected in biological pathways (P = 0.016) and that underlie skeletal growth defects (P<0.001). Second, the likely causal gene is often located near the most strongly associated variant: in 13 of 21 loci containing a known skeletal growth gene, that gene was closest to the associated variant. Third, at least 19 loci have multiple independently associated variants, suggesting that allelic heterogeneity is a frequent feature of polygenic traits, that comprehensive explorations of already-discovered loci should discover additional variants and that an appreciable fraction of associated loci may have been identified. Fourth, associated variants are enriched for likely functional effects on genes, being over-represented among variants that alter amino-acid structure of proteins and expression levels of nearby genes. Our data explain approximately 10% of the phenotypic variation in height, and we estimate that unidentified common variants of similar effect sizes would increase this figure to approximately 16% of phenotypic variation (approximately 20% of heritable variation). Although additional approaches are needed to dissect the genetic architecture of polygenic human traits fully, our findings indicate that GWA studies can identify large numbers of loci that implicate biologically relevant genes and pathways
Crown prince Rudolf and the Reform of the Habsburg Monarchy
No full textThe aim of this bachelor thesis is an analysis of Crown Prince Rudolf's opinions as reflected in his original texts, primarily in his newspaper articles, which were published anonymously. The author focuses on texts written about three main topics: Austrian nobility, Rudolf's attitude towards the many nations living within the Habsburg monarchy and the functionality of dualism or the possibility of a different form of government. The author has used the following methods to explore these topics: analysis of newspaper articles, other original texts and analysis of correspondence with fellow journalist Moritz Szeps as well as literature search. The thesis presents the situation in the Austro-Hungarian monarchy in the 1870s and 1880s and describes Rudolf's position on the issue of nationalism in a multi-ethnic monarchy, his views concerning the Balkan question, religious tolerance and the Jewish question. The Crown Princes' opinion on dualism and its disadvantages compared to a unified empire, his attitude towards the possibility of further splitting of the monarchy or its federalization, and his opinion on the possibility of the monarchy's dissolution are also presented. Rudolf's asessment of the morals of the blue-blooded and their attitude towards science and progress are also analysed. Both the...Cílem této práce je analýza názorů korunního prince Rudolfa prezentovaných v jeho autorských textech, primárně v anonymně vydávaných novinových článcích. Autorka se na zaměřila na texty psané o šlechtě, Rudolfově postoji k národům uvnitř mnohonárodnostní habsburské monarchie a o funkčnosti dualismu či možnosti jiného uspořádání monarchie. Pro zkoumání tématu byla využita analýza novinových článků i dalších textů, korespondence s novinářem Moritzem Szepsem a rešerše v literatuře. Práce seznámí čtenáře se situací v monarchii v 80. letech 19. století a s postojem korunního prince Rudolfa k otázce nacionalistických tendencí v mnohonárodnostní monarchii, balkánské otázce, náboženské toleranci a židovské otázce. Je představen Rudolfův názor na dualismus a nevýhody tohoto systému oproti jednotné říši, jeho postoj k možnosti dalšího štěpení monarchie či její federalizace a názor na možnost zániku monarchie. Analyzováno bylo také princovo hodnocení mravů šlechty, jejího postoje k vědě a pokroku a rovněž hodnocení vzdělanosti aristokracie či její připravenosti k aktivní účasti v politickém životě.Institute of General HistoryÚstav světových dějinFaculty of ArtsFilozofická fakult
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