A utilização de espécies selvagens como doadoras de variabilidade é uma das estratégias utilizadas nos últimos anos como alternativa viável para espécies que possuem base genética estreita. A espécie de arroz cultivada, Oryza sativa, de ampla distribuição, também viu afetada sua variabilidade pelos intensivos programas de melhoramento, no Brasil e em todos os países produtores de arroz a nível mundial. A utilização repetida de poucas cultivares elite como progenitores para a formação de novas variedades é indicada como a principal causa deste estreitamento. Na Bacia Amazônica se localizam quatro espécies do gênero Oryza, sendo três tetraplóides e uma diplóide, O. glumaepatula. Esta última possui grande potencialidade como doadora de variabilidade devido à similaridade do seu genoma com a espécie cultivada, além de estar adaptada as condições climáticas do Brasil. Cruzamentos interespecíficos são possíveis entre as duas espécies. No entanto, os indivíduos derivados apresentam uma performance distante de variedades modernas porque neles se conjugam novamente alguns caracteres eliminados durante o processo de domesticação da espécie. O objetivo deste trabalho foi selecionar famílias RC1F3 promissoras que tenham recuperado a maioria dos caracteres de interesse agronômico e identificar genótipos transgressivos para alguns deles. Devido à limitada disponibilidade de sementes produzidas durante a geração anterior, as famílias foram avaliadas em blocos aumentados em condições de campo irrigado. Foram avaliados 13 caracteres morfológicos de interesse agronômico como altura, deiscência, comprimento da panícula, número de espiguetas por panícula, entre outros. Também foi estimada a produtividade de grãos para cada família. Análises de agrupamento também foram realizadas, utilizando a distância Euclidiana como medida de dissimilaridade e método UPGMA (Unweighted pair group method with arithmetic average), onde foram estabelecidas as relações entre o material avaliado, as famílias avaliadas e o parental recorrente (variedade IAC 102) e outras variedades utilizadas como controle. Em geral, as famílias avaliadas apresentaram uma performance menor que o parental recorrente. No entanto, observou-se fenótipos transgressivos para alguns caracteres como comprimento de panícula, número de espigueta por panícula, comprimento e largura de folha bandeira. Foram observadas famílias de porte baixo e maior comprimento de panícula, indicando que a correlação existente entre altura e comprimento de panícula foi quebrada nesta geração Algumas famílias apresentaram produtividade superior em relação ao parental recorrente, até 45% a mais que a variedade IAC 102. Os dendrogramas obtidos através da análise de agrupamento permitem inferir a existência de uma divergência importante entre as famílias F3 e as variedades utilizadas na comparação. Foi possível a separação de grupos definidos pela combinação de caracteres divergentes. No total, 27 famílias foram selecionadas por apresentarem uma performance semelhante ao parental recorrente, ou por possuir caracteres de interesse para serem introgredidos nas cultivares de arroz, como maior número de espiguetas por panícula ou produtividade superior. A obtenção de fenótipos transgressivos indicam a presença de alelos favoráveis na espécie silvestre O. gluamaepatula, mostrando seu grande potencial nos programas de melhoramento como fonte de caracteres de interesse. / The utilization of wild species as donors of variability is one of the strategies used in the last years as a viable alternative for species that present a narrow genetic base. The genetic variability of the cultivated species, Oryza sativa, of wide distribution, has also been affected by the intensive breeding programs, in Brazil, and at all the other rice producing countries. The repetitive use of few elite cultivars as progenitors in the establishment of new varieties is indicated as the main cause of this narrow genetic base. In the Amazon Basin, four species of the genus Oryza occurs naturally, three tetraploid and one diploid species, O. glumaepatula. The latter presents great potentiality as donor of variability due to the genome similarity with the cultivated species, besides being well adapted to the Brazilian climatic conditions. It is possible to obtain interspecific crosses between both species. However, individuals derived from these crossings present a performance which is distant from the modem varieties, as those characters eliminated during the domestication process tend to appear once more in the same individual. The objective of this study was to select promising BC1F3 families that have recovered most of the characters of agronomic interest and identify transgressive genotypes for some of these characters. Due to the low availability of seeds produced during the previous generation, the families were evaluated in xi augmented blocks under field conditions. Thirteen morphological characters of agronomic interest were evaluated, such as plant height, shattering, panicle length, spikelet number per panicle, among others. Grain productivity was also estimated for each family. Cluster analysis were also conducted, using Euclidean distance as a measure of dissimilarity and the UPGMA (Unweighed pair group method with arithmetic average) method, where the relationship among the families and the recurrent parent (IAC 102 variety) as well as the other commercial varieties used as controls were established. In general, the evaluated families presented a lower performance than the recurrent parent. However, transgressive phenotypes were observed for some characters such as panicle length, spikelet number per panicle, length and width of the flag leaf. Families of lower height and higher panicle length were observed, indicating that the correlation among plant height and panicle length was broken in this generation. Some families presented a superior productivity in relation to the recurrent parent, up to 45% higher than IAC 102 variety. The dendrograms obtained in the cluster analysis allows us to infer on the existence of important divergence among F3 families and the varieties used for comparison. It was possible to separate groups defined by the combination of divergent characters. In total, 27 families were selected for presenting a similar performance to the recurrent parent, or for possessing characters of interest to be introgressed into rice cultivars, such as a higher spikelet number per panicle or superior productivity. The finding of transgressive phenotypes indicate the presence of favorable alleles in the wild species O. glumaepatula, showing its great potential for breeding programs as a source of characters of interest.

<p>Control systems utilizing wireless sensor and actuator networks can be severely affectedby the properties of the communication links. Radio fading and interferencemay cause communication losses and outages in situations when the radio environmentis noisy and low transmission power is desirable. This thesis proposes amethod to compensate for such unpredictable losses of data in the feedback controlloop by introducing a predictive outage compensator (POC). The POC is a filter tobe implemented at the receiver sides of networked control systems where it generatesartificial samples when data are lost. If the receiver node does not receive thedata, the POC suggests a command based on the history of past data. It is shownhow to design, tune and implement a POC. Theoretical bounds and simulationresults show that a POC can improve the closed-loop control performance undercommunication losses considerably. We provide a deterministic and a stochasticmethod to synthesize POCs. Worst-case performance bounds are given that relatethe closed-loop performance with the complexity of the compensator. We also showthat it is possible to achieve good performance with a low-order implementationbased on Hankel norm approximation. Tradeoffs between achievable performance,communication loss length, and POC order are discussed. The results are illustratedon a simulated example of a multiple-tank process. The thesis is concludedby an experimental validation of wireless control of a physical lab process. Herethe controller and the physical system are separated geographically and interfacedthrough a wireless medium. For the remote control we use a hybrid model predictivecontroller. The results reflect the difficulties in wireless control as well as theyhighlight the flexibility and possibilities one obtains by using wireless instead of awired communication medium.</p> / VR, SSF, VINNOVA via Networked Embedded Control Systems, EU Sixt Framework Program via HYCON and SOCRADES

<img src="http://vg00.met.vgwort.de/na/806c85cec18906a64e06" width="1" height="1" alt=""> Subject of this work is the possibility to synchronize nonlinear systems via correlated noise and automatic control. The thesis is divided into two parts.<br> The first part is motivated by field studies on feral sheep populations on two islands of the St. Kilda archipelago, which revealed strong correlations due to environmental noise. For a linear system the population correlation equals the noise correlation (Moran effect). But there exists no systematic examination of the properties of nonlinear maps under the influence of correlated noise. Therefore, in the first part of this thesis the noise-induced correlation of logistic maps is systematically examined. For small noise intensities it can be shown analytically that the correlation of quadratic maps in the fixed-point regime is always smaller than or equal to the noise correlation. In the period-2 regime a Markov model explains qualitatively the main dynamical characteristics. Furthermore, two different mechanisms are introduced which lead to a higher correlation of the systems than the environmental correlation. The new effect of "correlation resonance" is described, i. e. the correlation yields a maximum depending on the noise intensity. <br> In the second part of the thesis an automatic control method is presented which synchronizes different systems in a robust way. This method is inspired by phase-locked loops and is based on a feedback loop with a differential control scheme, which allows to change the phases of the controlled systems. The effectiveness of the approach is demonstrated for controlled phase synchronization of regular oscillators and foodweb models. / Gegenstand der Arbeit ist die Möglichkeit der Synchronisierung von nichtlinearen Systemen durch korreliertes Rauschen und automatische Kontrolle. Die Arbeit gliedert sich in zwei Teile.<br> Der erste Teil ist motiviert durch Feldstudien an wilden Schafspopulationen auf zwei Inseln des St. Kilda Archipels, die starke Korrelationen aufgrund von Umwelteinflüssen zeigen. In einem linearen System entspricht die Korrelation der beiden Populationen genau der Rauschkorrelation (Moran-Effekt). Es existiert aber noch keine systematische Untersuchung des Verhaltens nichtlinearer Abbildungen unter dem Einfluss korrelierten Rauschens. Deshalb wird im ersten Teils dieser Arbeit systematisch die rauschinduzierte Korrelation zweier logistischer Abbildungen in den verschiedenen dynamischen Bereichen untersucht. Für kleine Rauschintensitäten wird analytisch gezeigt, dass die Korrelation von quadratischen Abbildungen im Fixpunktbereich immer kleiner oder gleich der Rauschkorrelation ist. Im Periode-2 Bereich beschreibt ein Markov-Modell qualitativ die wichtigsten dynamischen Eigenschaften. Weiterhin werden zwei unterschiedliche Mechanismen vorgestellt, die dazu führen, dass die beiden ungekoppelten Systeme stärker als ihre Umwelt korreliert sein können. Dabei wird der neue Effekt der "correlation resonance" aufgezeigt, d. h. es ergibt sich eine Resonanzkurve der Korrelation in Abbhängkeit von der Rauschstärke. <br> Im zweiten Teil der Arbeit wird eine automatische Kontroll-Methode präsentiert, die es ermöglicht sehr unterschiedliche Systeme auf robuste Weise in Phase zu synchronisieren. Die Methode ist angelehnt an Phase-locked-Loops und basiert auf einer Rückkopplungsschleife durch einen speziellen Regler, der es erlaubt die Phasen der kontrollierten Systeme zu ändern. Die Effektivität dieser Methode zur Kontrolle der Phasensynchronisierung wird an regulären Oszillatoren und an Nahrungskettenmodellen demonstriert.

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No description available.

Univ., Diplomarbeit, 2002--Frankfurt (Main)

Stuttgart, Univ., Diss., 2006. / Druckausg. beim Logos-Verlag, Berlin erschienen.

Diss., Technische Wissenschaften, Eidgenössische Technische Hochschule ETH Zürich, Nr. 17277, 2007.

Diss., Technische Wissenschaften, Eidgenössische Technische Hochschule ETH Zürich, Nr. 17760, 2008.

Diss., Technische Wissenschaften, Eidgenössische Technische Hochschule ETH Zürich, Nr. 17760, 2008.