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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.
1

Prioritized data synchronization with applications

Jin, Jiaxi January 2013 (has links)
We are interested on the problem of synchronizing data on two distinct devices with differed priorities using minimum communication. A variety of distributed sys- tems require communication efficient and prioritized synchronization, for example, where the bandwidth is limited or certain information is more time sensitive than others. Our particular approach, P-CPI, involving the interactive synchronization of prioritized data, is efficient both in communication and computation. This protocol sports some desirable features, including (i) communication and computational com- plexity primarily tied to the number of di erences between the hosts rather than the amount of the data overall and (ii) a memoryless fast restart after interruption. We provide a novel analysis of this protocol, with proved high-probability performance bound and fast-restart in logarithmic time. We also provide an empirical model for predicting the probability of complete synchronization as a function of time and symmetric differences. We then consider two applications of our core algorithm. The first is a string reconciliation protocol, for which we propose a novel algorithm with online time com- plexity that is linear in the size of the string. Our experimental results show that our string reconciliation protocol can potentially outperform existing synchroniza- tion tools such like rsync in some cases. We also look into the benefit brought by our algorithm to delay-tolerant networks(DTNs). We propose an optimized DTN routing protocol with P-CPI implemented as middleware. As a proof of concept, we demonstrate improved delivery rate, reduced metadata and reduced average delay.
2

Chaotic system synchronization with an unknown master model using a hybrid HOD active control approach

Du, S, Van Wyk, BJ, Qi, G, Tu, C 25 March 2009 (has links)
a b s t r a c t In this paper, a hybrid method using active control and a High Order Differentiator (HOD) methodology is proposed to synchronize chaotic systems. Compared to some traditional active control methods, this new method can synchronize chaotic systems where only output states of the master system are available, i.e. the system is considered a black box. The HOD is used to estimate the derivative information of the master system followed by an active control methodology relying on HOD information. The Qi hyperchaotic system is used to verify the performance of this hybrid method. The proposed method is also compared to some traditional methods. Experimental results show that the proposed method has high synchronization precision and speed and is robust against uncertainties in the master system. The circus implements of the proposed synchronizing scheme are included in this paper. The simulation results show the feasibility of the proposed scheme.
3

AN IMPROVED METHOD FOR SYNCHRONIZING MULTIPLE TM FILES

Terrien, Ron, Endress, William 11 1900 (has links)
In a previous paper “Merging Multiple Telemetry Files From Widely Separated Sources For Improved Data Integrity” presented at the 2012 ITC\USA conference, a method for synchronizing TM files at the minor frame level was presented. This paper expands on that work by describing a method for synchronizing the files at the minor frame level faster and at the earliest frame possible using an internal counter. This method is also useful if the minor frames fall out of sync due to large dropouts.
4

A decision support system for synchronizing manufacturing in a multifacility production system

Matz, Thomas W. January 1989 (has links)
No description available.
5

Autômatos sincronizados e a Conjectura de Cerný / Synchronizing Automata and the Cerný Conjecture

Gindri, Leticia 10 July 2013 (has links)
Cerný, em 1964, conjecturou que um autômato sincronizado com n estados possui uma palavra sincronizadora mínima de tamanho no máximo (n-1)². Esta conjectura permanece em aberto. Neste trabalho são apresentados algoritmos para obter palavras sincronizadoras e é feito um experimento comparativo entre os resultados obtidos por estes algoritmos em relação a algumas séries infinitas de autômatos. Por fim, é feito um breve histórico sobre os resultados parciais obtidos até a presente data e alguns destes trabalhos são apresentados em mais detalhes. / Cerný, on 1964, conjectured that a synchronizing automata with n states has a synchronizing word of size at most (n-1)². The conjecture remains open. We show some algorithms for obtaining synchronizing sequences and a comparative experiment between these algorithms with respect to some infinite series of automata. Furthermore, we briefly survey some of the partial results obtained until the present day.
6

Analýza vybraných vlivů na reprodukci dojnic u stáda holštýnského skotu / The Analysis of Selected Impacts on Reproduction of Dairy Cows in a Herd of Holstein Cattle

PROVAZNÍK, Pavel January 2013 (has links)
The diploma thesis deals with the analysis of selected effects on reproduction of Holstein dairy cows. Breeding of cattle faces up to so impaired indicators of reproduction that it could cause the decrease of economic efficiency in production of milk and meat. The aim of the thesis is the evaluation of selected effects that influence the reproduction of dairy cows in the farm in Trhový Štěpánov. Information about reproduction were gained from records of efficiency controls and animal husbandry records of the year 2012. The observation included total 515 Holstein dairy cows (H100) and 1 784 inseminations were carried out. From this amount 350 dairy cows were gravid. Gained data were selected by sequence of lactation, level of dairy efficiency, inseminating bulls and synchronizing programmes. Established results showed that the only reliable indicator was the interval of insemination. Average length of interval of insemination amounted to 79,9 days. The other figures of reproduction indicators were found out below-average comparing the avarage figures of Holstein cattle. Average service period of studied dairy cows was 197,1 days and the length of between-period was 477,1 days. It was found out very low average percentage of gravidity after the first insemination (12,6 %). Average number of doses of insemination for one gravid cow was 3,5. The biggest effect on reproduction indicators had the level of dairy efficiency (P < 0,05). The shortest service period and between-period had dairy cows with efficiency of 7 000 to 10 000 kg of milk. It was not proved the influence of RPH of breeding bulls for gravidity of breeding-cows. The highest percentage of gravidity after all inseminations was after application of EOSTROPHAN (30,5 %). The worst synchronizing programme was DOUBLE OVSYNCH (12 %). The percentage of gravidity after all inseminations and synchronizing programmes was 20,4 % and after spontaneous rut only 15 %.
7

Autômatos sincronizados e a Conjectura de Cerný / Synchronizing Automata and the Cerný Conjecture

Leticia Gindri 10 July 2013 (has links)
Cerný, em 1964, conjecturou que um autômato sincronizado com n estados possui uma palavra sincronizadora mínima de tamanho no máximo (n-1)². Esta conjectura permanece em aberto. Neste trabalho são apresentados algoritmos para obter palavras sincronizadoras e é feito um experimento comparativo entre os resultados obtidos por estes algoritmos em relação a algumas séries infinitas de autômatos. Por fim, é feito um breve histórico sobre os resultados parciais obtidos até a presente data e alguns destes trabalhos são apresentados em mais detalhes. / Cerný, on 1964, conjectured that a synchronizing automata with n states has a synchronizing word of size at most (n-1)². The conjecture remains open. We show some algorithms for obtaining synchronizing sequences and a comparative experiment between these algorithms with respect to some infinite series of automata. Furthermore, we briefly survey some of the partial results obtained until the present day.
8

Měřicí systém pro laboratorní generátorové soustrojí / Measuring system for laboratory generator unit

Pochop, Zbyněk January 2013 (has links)
This Master thesis deals with the measurement and description of the synchronous generator , which is located in laboratories. First, the thesis deals with the theory of synchronous machines. This is followed by a detailed description of the involvement of laboratory genetatory unit. Subsequently, the work deals with the measurement of basic parameters of the synchronous machine and also quite thoroughly devoted to displaying transients at various levels on the digital oscilloscope. The dissertation aims to compare theoretical ideas with the measured results. Finally, it is shown what could be measured next to the generator set.
9

Contrôle, synchronisation et chiffrement / Control, synchronization and encryption

Parriaux, Jérémy 03 October 2012 (has links)
Cette thèse traite de la synchronisation des systèmes dynamiques.La synchronisation est étudiée pour une configuration de type maître-esclave, c'est-à-dire pour des systèmes couplés de façon unidirectionnelle. Ce type de configuration s'avère d'un intérêt tout particulier car elle correspond à des architectures de communications chiffrées un-vers-un ou un-vers-plusieurs. Une attention spécifique est portée sur l'autosynchronisation, comportement qui caractérise la synchronisation par le simple couplage maître-esclave et donc en l'absence de tout contrôle extérieur. Elle joue un rôle majeur dans les communications impliquant des chiffreurs par flot autosynchronisants. L'étude de l'autosynchronisation dans le contexte cryptographique s'appuie sur la théorie du contrôle. Un lien original entre l'autosynchronisation et le principe de chiffrement/déchiffrement en cryptographie est mis en évidence. Il fait appel à la propriété de platitude des systèmes dynamiques, un concept emprunté à l'automatique. On montre que les systèmes dynamiques plats définissent complètement l'ensemble des systèmes autosynchronisants et permettent d'élargir les structures existantes des chiffreurs autosynchronisants. La platitude est tout d'abord étudiée pour deux types de systèmes non linéaires~: les systèmes linéaires commutés et à paramètres variants (LPV). La caractérisation des sorties plates s'appuie sur le concept de semigroupes nilpotents et un algorithme performant est proposé. Une approche constructive pour réaliser des structures maître-esclave autosynchronisantes est proposée sur la base de systèmes plats et les notions d'inversibilité à gauche et à droite empruntées à la théorie du contrôle. Par la suite, l'autosynchronisation est étudiée dans le contexte booléen, privilégié en cryptographie.Elle est caractérisée en premier lieu au travers la notion d'influence. Ensuite, différentes représentations matricielles associées aux fonctions booléennes sont proposées. Ces représentations s'avèrent particulièrement intéressantes pour l'analyse des propriétés liées à la sécurité. Un lien entre l'autosynchronisation et les structures propres des représentations matricielles est établi. Une approche orientée graphes est finalement élaborée pour la caractérisation. De nouvelles constructions de structures autosynchronisantes en sont déduites et des éléments de sécurité sont discutés. Enfin, une plateforme de test à base de FPGA qui a été réalisée est décrite / This thesis deals with the synchronization of dynamical systems. The synchronization considered is called master-slave, that is, the dynamical systems are connected in a unidirectional way. This configuration is of interest because it corresponds to an architecture encountered in secured communications of type one-to-one or one-to-many. A special attention is paid to self-synchronization. A behaviour that characterizes synchronization achieved with a simple master-slave coupling and so, without any external control. It is a central feature of self-synchronizing stream ciphers. The study of self-synchronization in the cryptographic context relies on control theory. An original connection between self-synchronization and encryption/decryption is provided. It is based on the flatness property of dynamical systems, a property borrowed from automatic control. It is shown that flat dynamical systems completly define the set of all self-synchronizing systems and thus, enlarge the existing structures of self-synchronizing stream ciphers. Flatness is first of all studied for the case of two nonlinear systems: switched linear systems and linear parameter-varying (LPV) systems. Flatness caracterization is based on the concept of nilpotent semigroups and an efficient algorithm is provided. A constructive approach for self-synchronizing master-slave structures is proposed. It relies on the construction of flat systems as well as on left and right invertibility also borrowed from control theory. Then, self-synchronization is studied in the Boolean context which is preferred in cryptography. Self-synchronization is caracterized through the notion of influence. Several matrix representations of Boolean functions are proposed. These representations are especially interesting for security analysis. A connection between self-synchronization and the eigenstructures of these matrices is established. Then, a graph oriented approach is provided. New self-synchronizing constructions are deduced and security elements are discussed. Eventually, the description of a realized FPGA based test plateform is provided
10

Evaluation of Fuel Saving for an Airline

Berglund, Tobias January 2008 (has links)
<p>A study of which methods and measures that can be used to reduce fuel consumption and harmful discharges in an airline.</p><p>The study begins with an investigation containing calculations of the differences between estimated fuel consumption calculated by a computer program called Skytrack and actual fuel consumption. Results from this study allows synchronization between actual consumption with calculated consumption. In addition to this methods and configurations to reduce weight and thus weight onboard aircrafts e.g. carpet exchange, lightweight trolleys and water reduction has been created and analysed.</p><p>To bring the thesis to an end, the author has investigated other methods and configurations which TUIfly Nordic is implementing for fuel conservation.</p><p>The thesis results in several conceivable areas for fuel conservation with calculated savings of 830 000 EUR which for the moment is implemented in TUIFly Nordic.</p>

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