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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Template-basierte Klassifikation planarer Gesten

Schmidt, Michael 25 April 2014 (has links)
Pervasion of mobile devices led to a growing interest in touch-based interactions. However, multi-touch input is still restricted to direct manipulations. In current applications, gestural commands - if used at all - are only exploiting single-touch. The underlying motive for the work at hand is the conviction that a realization of advanced interaction techniques requires handy tools for supporting their interpretation. Barriers for own implementations of procedures are dismantled by providing proof of concept regarding manifold interactions, therefore, making benefits calculable to developers. Within this thesis, a recognition routine for planar, symbolic gestures is developed that can be trained by specifications of templates and does not imply restrictions to the versatility of input. To provide a flexible tool, the interpretation of a gesture is independent of its natural variances, i.e., translation, scale, rotation, and speed. Additionally, the essential number of specified templates per class is required to be small and classifications are subject to real-time criteria common in the context of typical user interactions. The gesture recognizer is based on the integration of a nearest neighbor approach into a Bayesian classification method. Gestures are split into meaningful, elementary tokens to retrieve a set of local features that are merged by a sensor fusion process to form a global maximum-likelihood representation. Flexibility and high accuracy of the approach is empirically proven in thorough tests. Retaining all requirements, the method is extended to support the prediction of partially entered gestures. Besides more efficient input, the possible specification of direct manipulation interactions by templates is beneficial. Suitability for practical use of all provided concepts is demonstrated on the basis of two applications developed for this purpose and providing versatile options of multi-finger input. In addition to a trainable recognizer for domain-independent sketches, a multi-touch text input system is created and tested with users. It is established that multi-touch input is utilized in sketching if it is available as an alternative. Furthermore, a constructed multi-touch gesture alphabet allows for more efficient text input in comparison to its single-touch pendant. The concepts presented in this work can be of equal benefit to UI designers, usability experts, and developers of feedforward-mechanisms for dynamic training methods of gestural interactions. Likewise, a decomposition of input into tokens and its interpretation by a maximum-likelihood matching with templates is transferable to other application areas as the offline recognition of symbols. / Obwohl berührungsbasierte Interaktionen mit dem Aufkommen mobiler Geräte zunehmend Verbreitung fanden, beschränken sich Multi-Touch Eingaben größtenteils auf direkte Manipulationen. Im Bereich gestischer Kommandos finden, wenn überhaupt, nur Single-Touch Symbole Anwendung. Der vorliegenden Arbeit liegt der Gedanke zugrunde, dass die Umsetzung von Interaktionstechniken mit der Verfügbarkeit einfach zu handhabender Werkzeuge für deren Interpretation zusammenhängt. Auch kann die Hürde, eigene Techniken zu implementieren, verringert werden, wenn vielfältige Interaktionen erprobt sind und ihr Nutzen für Anwendungsentwickler abschätzbar wird. In der verfassten Dissertation wird ein Erkenner für planare, symbolische Gesten entwickelt, der über die Angabe von Templates trainiert werden kann und keine Beschränkung der Vielfalt von Eingaben auf berührungsempfindlichen Oberflächen voraussetzt. Um eine möglichst flexible Einsetzbarkeit zu gewährleisten, soll die Interpretation einer Geste unabhängig von natürlichen Varianzen - ihrer Translation, Skalierung, Rotation und Geschwindigkeit - und unter wenig spezifizierten Templates pro Klasse möglich sein. Weiterhin sind für Nutzerinteraktionen im Anwendungskontext übliche Echtzeit-Kriterien einzuhalten. Der vorgestellte Gestenerkenner basiert auf der Integration eines Nächste-Nachbar-Verfahrens in einen Ansatz der Bayes\'schen Klassifikation. Gesten werden in elementare, bedeutungstragende Einheiten zerlegt, aus deren lokalen Merkmalen mittels eines Sensor-Fusion Prozesses eine Maximum-Likelihood-Repräsentation abgeleitet wird. Die Flexibilität und hohe Genauigkeit des statistischen Verfahrens wird in ausführlichen Tests nachgewiesen. Unter gleichbleibenden Anforderungen wird eine Erweiterung vorgestellt, die eine Prädiktion von Gesten bei partiellen Eingaben ermöglicht. Deren Nutzen liegt - neben effizienteren Eingaben - in der nachgewiesenen Möglichkeit, per Templates spezifizierte direkte Manipulationen zu interpretieren. Zur Demonstration der Praxistauglichkeit der präsentierten Konzepte werden exemplarisch zwei Anwendungen entwickelt und mit Nutzern getestet, die eine vielseitige Verwendung von Mehr-Finger-Eingaben vorsehen. Neben einem Erkenner trainierbarer, domänenunabhängiger Skizzen wird ein System für die Texteingabe mit den Fingern bereitgestellt. Anhand von Nutzerstudien wird gezeigt, dass Multi-Touch beim Skizzieren verwendet wird, wenn es als Alternative zur Verfügung steht und die Verwendung eines Multi-Touch Gestenalphabetes im Vergleich zur Texteingabe per Single-Touch effizienteres Schreiben zulässt. Von den vorgestellten Konzepten können UI-Designer, Usability-Experten und Entwickler von Feedforward-Mechanismen zum dynamischen Lehren gestischer Eingaben gleichermaßen profitieren. Die Zerlegung einer Eingabe in Token und ihre Interpretation anhand der Zuordnung zu spezifizierten Templates lässt sich weiterhin auf benachbarte Gebiete, etwa die Offline-Erkennung von Symbolen, übertragen.
12

Ecriture chinoise, écriture occidentale : variantes de l'appréhension du monde / How to apprehend the world : approach through chinese writing, approach through western writing

Tung, Jui-Chu 03 December 2012 (has links)
Confronter la pensée occidentale à la pensée chinoise est une démarche enrichissante à un moment où les cultures se croisent et peuvent même se sentir menacées. J'ai tenté, en partant de l'étude des écritures et de leurs origines de mieux cerner l'avènement de la pensée et son développement dans les deux cas. Il s'agissait de fixer un champ d'étude, j'ai donc songé à présenter le 'réel', le' monde', selon les deux approches et applications, d'un côté le 'logos\ la Raison et de l'autre les conceptions taoïstes, parfois mêlées de bouddhisme. Le 'procès' du monde dont la Chine était très tôt consciente ne lui permettait pas d'interpréter le réel tel que la Grèce et par voie de conséquence l'Occident le concevait, la seule chose qui ne change pas dans le monde étant précisément pour la Chine l'état 'd'impermanence'. Partant notamment du "yi jing" ou "Livre des Mutations", de la construction idéographique, la Chine a voulu représenter le monde tout entier, elle avait une vision différente de celle de I'Occident...Mais une question demeure posée: quelle est au fond l'origine de cette vision ? Est-ce celle de certains penseurs ? Est-ce la nature elle-même ? Est-ce l'écriture comme manifestation humaine? Ma recherche propose quelques jalons pour chaque civilisation, mais la question reste très ouverte / Comparing Western thought and Chinese thought can be quite enriching, at a time when cultures in general can gain contact, as weil as fee!thrcatencd somctimes. l have tried, starting from modes of writings, at their origins, to figure out the advcnt and development ofthought on both sides. The point was also to choose a field ofexpcriment... 1 have thought that 1 could present 'reality', the 'world', from Western and Chinese approaches, with the efiècts of 'logos' and 'Reason' on one side and Taoist and sometimes Buddhist influences on the other. The 'process' of the world that China was conscious of cou id not allow her to apprchend reality such as Greece, very carly, and later Western thought could conceive it. Indeed, the only thing that would not change in this world is the state of 'impermanence' for China. From the yi jing, the Book of Changes, and ideographie patterns and methods, China wanted to show the world, the whole world. That was a vision definitely different from that of the West... Still, one question remains : where does this vision come from ? From thinkers. from Nature itself ? From modes of writings as human responses ? The exposition that I developed offers a few landmarks on both sidcs, but the question is still an open one...
13

Généralisations du Théorème d'Extension de MacWilliams / Generalizations of the MacWilliams Extension Theorem

Dyshko, Serhii 15 December 2016 (has links)
Le fameux Théorème d’Extension de MacWilliams affirme que, pour les codes classiques, toute isométrie deHamming linéaire d'un code linéaire se prolonge en une application monomiale. Cependant, pour les codeslinéaires sur les alphabets de module, l'existence d'un analogue du théorème d'extension n'est pas garantie.Autrement dit, il existe des codes linéaires sur certains alphabets de module dont les isométries de Hammingne sont pas toujours extensibles. Il en est de même pour un contexte plus général d'un alphabet de module munid'une fonction de poids arbitraire. Dans la présente thèse, nous prouvons des analogues du théorèmed'extension pour des codes construits sur des alphabets et fonctions de poids arbitraires. La propriétéd'extension est analysée notamment pour les codes de petite longueur sur un alphabet de module de matrices,les codes MDS généraux, ou encore les codes sur un alphabet de module muni de la composition de poidssymétrisée. Indépendamment de ce sujet, une classification des deux groupes des isométries des codescombinatoires est donnée. Les techniques développées dans la thèse sont prolongées aux cas des codesstabilisateurs quantiques et aux codes de Gabidulin dans le cadre de la métrique rang. / The famous MacWilliams Extension Theorem states that for classical codes each linear Hamming isometry ofa linear code extends to a monomial map. However, for linear codes over module alphabets an analogue of theextension theorem does not always exist. That is, there may exists a linear code over a module alphabet with anunextendable Hamming isometry. The same holds in a more general context of a module alphabet equippedwith a general weight function. Analogues of the extension theorem for different classes of codes, alphabetsand weights are proven in the present thesis. For instance, extension properties of the following codes arestudied: short codes over a matrix module alphabet, maximum distance separable codes, codes over a modulealphabet equipped with the symmetrized weight composition. As a separate result, a classification of twoisometry groups of combinatorial codes is given. The thesis also contains applications of the developedtechniques to quantum stabilizer codes and Gabidulin codes.
14

Directed Evolution of Glutathione Transferases with Altered Substrate Selectivity Profiles : A Laboratory Evolution Study Shedding Light on the Multidimensional Nature of Epistasis

Zhang, Wei January 2011 (has links)
Directed evolution is generally regarded as a useful approach in protein engineering. By subjecting members of a mutant library to the power of Darwinian evolution, desired protein properties are obtained. Numerous reports have appeared in the literature showing the success of tailoring proteins for various applications by this method. Is it a one-way track that protein practitioners can only learn from nature to enable more efficient protein engineering? A structure-and-mechanism-based approach, supplemented with the use of reduced amino acid alphabets, was proposed as a general means for semi-rational enzyme engineering. Using human GST A2-2*E, the most active human enzyme in the bioactivation of azathioprine, as a parental enzyme to test this approach, a L107G/L108D/F222H triple-point mutant of GST A2-2*E (thereafter designated as GDH) was discovered with 70-fold increased activity, approaching the upper limit of specific activity of the GST scaffold. The approach was further experimentally verified to be more successful than intuitively choosing active-site residues in proximity to the bound substrate for the improvement of enzyme performance. By constructing all intermediates along all putative mutational paths leading from GST A2-2*E to mutant GDH and assaying them with nine alternative substrates, the fitness landscapes were found to be “rugged” in differential fashions in substrate-activity space. The multidimensional fitness landscapes stemming from functional promiscuity can lead to alternative outcomes with enzymes optimized for other features than the selectable markers that were relevant at the origin of the evolutionary process. The results in this thesis suggest that in this manner an evolutionary response to changing environmental conditions can readily be mounted. In summary, the thesis demonstrates the attractive features of the structure-and-mechanism-based semi-rational directed evolution approach for optimizing enzyme performance. Moreover, the results gained from the studies show that laboratory evolution may refine our understanding of evolutionary process in nature.

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