Inorganic alternating current electroluminescent devices (AC-ELs) are known for their ruggedness and extreme long-term reliability, which is why they can often been found in industrial and medical equipment as well as in applications in the military sector. In contrast to the inorganic phosphors used in AC-ELs, organic materials offer a number of advantages, in particular a significantly higher efficiency, easier processibility, and a wide selection of emitter materials spanning the entire visible spectrum. Several efforts towards alternating current driven organic light-emitting devices have recently been made, however, important operating mechanism are still not well understood. In the first part of this theses, alternating current driven, capacitively coupled, pin-based organic light-emitting devices are investigated with respect to the influence of the thickness of the insulating layer and the intrinsic organic layer on the driving voltage. A three-capacitor model is employed to predict the basic behavior of the devices and good agreement with the experimental values is found. The proposed charge regeneration mechanism based on Zener tunneling is studied in terms of field strength across the intrinsic organic layers. A remarkable consistency between the measured field strength at the onset point of light emission (3–3.1 MV/cm) and the theoretically predicted breakdown field strength of around 3 MV/cm is obtained. The latter value represents the field required for Zener tunneling in wide band gap organic materials according to Fowler-Nordheim theory. In a second step, asymmetric driving of capacitively coupled OLEDs is investigated. It is found that different voltages and/or pulse lengths for positive and negative half-cycle lead to significant improvements in terms of brightness and device efficiency. Part two of this work demonstrates a device concept for highly efficient organic light-emitting devices whose emission color can be easily adjusted from, e.g., deep-blue through cold-white and warm-white to saturated yellow. The presented approach exploits the different polarities of the positive and negative half-cycles of an alternating current driving signal to independently address a fluorescent blue emission unit and a phosphorescent yellow emission unit vertically stacked on top of each other. The electrode design is optimized for simple fabrication and driving and allows for two-terminal operation by a single source. The presented approach for color-tunable OLEDs is versatile in terms of emitter combinations and meets application requirements by providing a high device efficiency of 36.2 lm/W, a color rendering index of 82 at application relevant brightness levels of 1000 cd/m², and warm-white emission color coordinates. The final part demonstrates an approach for full-color OLED pixels that are fabricated by vertical stacking of a red-, green-, and blue-emitting unit. Each unit can be addressed separately which allows to efficiently generate every color that is a superposition of spectra of the individual emission units. The device is built in a top-emission geometrywhich is highly desirable for display fabrication as the pixel can be directly deposited onto the back-plane electronics. Furthermore, the presented device design requires only three independently addressable electrodes which simplifies fabrication and electrical driving. The electrical performance of each individual unit is on par with standard pin single emission unit OLEDs, showing very low leakage currents and achieving high brightness levels at moderate voltages of around 3–4 V.

No description available.

Result of this work is a reconstruction of proof, that non-deterministic linear time is strictly more powerful than deterministic linear time. We focus on completeness and clarity either of proof itself, either of all auxiliary propositions, which lead to this result.

Cette thèse se situe dans le domaine de la combinatoire algébrique. Autrement dit, l'idée est d'utiliser des structures algébriques, en l'occurence des algèbres de Hopf combinatoires, pour mieux étudier et comprendre les objets combinatoires ainsi que des algorithmes de composition et de décomposition agissant sur ces objets. Ce travail de recherche repose sur la construction et l'étude de structure algébrique sur des objets combinatoires généralisant les permutations. Après avoir rappelé le contexte et les notations des différents objets intervenant dans cette recherche, nous proposons dans la seconde partie l'étude de l'algèbre de Hopf introduite par Aguiar et Orellana indexée par les permutations de blocs uniformes. En se focalisant sur une description de ces objets via d'autres bien connus, les permutations et les partitions d'ensembles, nous proposons une réalisation polynomiale et une étude plus simple de cette algèbre. La troisième partie étudie une deuxième généralisation en interprétant les permutations comme des matrices. Nous définissons et étudions alors des familles de matrices carrées sur lesquelles nous définissons des algorithmes de composition et de décomposition. La quatrième partie traite des matrices à signes alternants. Après avoir définie l'algèbre de Hopf sur ces matrices, nous étudions des statistiques et le comportement de la structure algébrique vis-à-vis de ces statistiques. Tous ces chapitres s'appuient fortement sur l'exploration informatique, et fait l'objet d'une implémentation utilisant le logiciel Sage. Ce dernier chapitre est consacré à la découverte et la manipulation de structures algébriques sur Sage. Nous terminons en expliquant les améliorations apportées pour l'étude de structure algébrique au travers du logiciel Sage / This thesis is in the field of algebraic combinatorics. In other words, the idea is to use algebraic structures, in this case of combinatorial Hopf algebras, to better study and understand the combinatorial objects and algorithms for composition and decomposition about these objects. This research is based on the construction and study of algebraic structure of combinatorial objects generalizing permutations. After recalling the background and notations of various objects involved in this research, we propose, in the second part, the study of the Hopf algebra introduced by Aguiar and Orellana based on uniform block permutations. By focusing on a description of these objects via well-known objects, permutations and set partitions, we propose a polynomial realization and an easier study of this algebra. The third section considers a second generalization interpreting permutations as matrices. We define and then study the families of square matrices on which we define algorithms for composition and decomposition. The fourth part deals with alternating sign matrices. Having defined the Hopf algebra of these matrices, we study the statistics and the behavior of the algebraic structure with these statistics. All these chapters rely heavily on computer exploration, and is the subject of an implementation using Sage software. This last chapter is dedicated to the discovery and manipulation of algebraic structures on Sage. We conclude by explaining the improvements to the study of algebraic structure through the Sage software

Nesta dissertação, estudamos cadeias unidimensionais antiferromagnéticas de spins 1/2 modeladas pelo Hamiltoniano de Heisenberg na presença de inomogeneidades causadas principalmente pela introdução de ligações substitucionais (defeitos nas ligações) e por efeitos de borda. Interessados então em determinar a energia do estado fundamental de sistemas com quaisquer distribuições das ligações, utilizamos o formalismo da Teoria do Funcional da Densidade (DFT) desenvolvido para o modelo de Heisenberg. O formalismo da DFT permite a estimativa da energia do estado fundamental de sistemas não-homogêneos conhecendo-se o sistema homogêneo. Construímos funcionais na aproximação da ligação local (LBA), proposta recentemente em analogia à já conhecida LSA (aproximação local para o spin). A obtenção dos funcionais se baseou no estudo do modelo de uma cadeia de spins em que as ligações são alternadas, isto é, a interação de troca se alterna em valor de sítio para sítio. Isso originou um funcional não-local na interação de troca da cadeia. Apesar disso, continuamos utilizando a nomenclatura LBA. Todos os resultados fornecidos pelos funcionais são comparados a dados provenientes de diagonalização numérica exata. / In this dissertation, we use the Heisenberg model to describe inhomogeneous antiferromagnetic spin 1/2 chains. The translational invariance is broken mainly due to the non-uniform distribution of bond interactions (defects) and the presence of boundaries. Interested in obtaining the ground-state energy of systems with any distribution of exchange couplings (Jij), we use the density-functional theory (DFT) formalism, developed for the Heisenberg model. The DFT formalism allows an estimate of the ground-state energy of inhomogeneous systems based on the homogeneous systems. We build functionals for the ground-state energy using a local bond approximation (LBA), recently proposed in analogy to the already known LSA (local spin approximation). To obtain the functionals we studied a model that describes an alternating chain, in which the exchange coupling alternates from site-to-site. This resulted in non-local functionals on the spin-spin exchange interaction. Nevertheless, we still call them LBA functionals. All the results from the functionals are compared with exact numerical data.

Introdução: A enurese noturna (EN) é considerada como a eliminação de urina no período noturno, de forma involuntária, em indivíduos com cinco ou mais anos de idade em pelo menos duas noites no mês até todas as noites. EN pode ser do tipo monossintomática, quando ocorre na ausência de outros sintomas, ou não monossintomática, na presença de sintomas de vesicais diurnos. Apesar de historicamente conhecida com uma desordem psiquiátrica, a EN monossintomática está incluída na Classificação Internacional dos Transtornos de 2012 como uma parassonia podendo ocorrer em qualquer fase do sono, porém predominantemente no sono não REM. Está comumente associada a hiperatividade vesical, produção excessiva de urina e falha em acordar após o enchimento vesical. Apesar de ocorrer no sono, a avaliação do sono pelos padrões usuais falhou em encontrar justificativa para este processo patológico. A análise da microestrutura do sono é uma ferramenta mais refinada e precisa que pode auxiliar na busca do mecanismo neurofisiológico que justifica este processo. Objetivo: Analisar os padrões de microarquitetura de sono atrvés do Padrão alternante Cíclico (CAP) nas crianças com EN monossintomática para melhor compreensão das bases neurofisiológicas da EN. Metodologia: Trinta e seis crianças sendo, 22 enuréticos e 14 controles com idade variando entre sete e 17 anos de idade, que satisfizeram os critérios de inclusão, foram submetidas a triagem clínica e laboratorial, avaliados quanto aos aspectos do sono, com uso de diários de sono, das escalas de Berlin, Sleep Scale for Children (SDSC) e Escala de Sonolência de Epworth e posteriormente submetidos ao de estudo polissonográfico completo de noite inteira, com a avaliação do CAP. Resultados: As escalas de sonolência e de Berlin não evidenciaram anormalidades, o SDSC evidenciou apneia em 11/22 (50%), hiperidrose em 2/22 (9%) e transtorno da transição vigília-sono, do despertar e do início e manutenção de sono em 1/22 (4,5%) cada. A análise da estrutura do sono mostrou maiores números de despertares (p < 0,001) e de sono N2 (p=0,0025) além de maior quantidade de sono N3 (p < 0,0001) do que nos controles. A microestrutura do sono evidenciou aumento da fase A1 (p=0,05), porém de forma mais contundente, redução das fases A2 e A3 (p < 0,0001), mesmo com a taxa de CAP igual à dos controles normais.Conclusão: Crianças com EN possuem sono com comorbidades (avaliado pelo SDSC) e menos fases CAP A2 e A3, significando uma redução no seu mecanismo de despertar e que ainda não havia sido demonstrado num estudo de PSG com análise das variáveis comuns. Este é o primeiro estudo que demonstra tal fenômeno / Introduction: Nocturnal enuresis (NE) is defined as the lack of nocturnal urine control, in individuals with five or more years old for at least two nights in a month, but up to every night. EN can be monosymptomatic (ENM), when it occurs in the absence of other symptoms or non monosymptomatic in the presence of diurnal renal symptoms. Although historically known as a psychiatric disorder, ENM is included in the International Classification of Sleep Disorders 2012 as a parasomnia. It can occur at any sleep stage but predominantly in non-REM sleep. EN is commonly associated to bladder hyperactivity, excessive urine production and/or failure to wake up after bladder filling. Despite the occurrence in sleep, standard sleep evaluation has failed to find abnormalities. The analysis of sleep microstructure is a refined and more accurate tool that can help find the neurophysiological mechanism underlying this process. Purpose: To evaluate sleep microarchitecture through Clyclic Altenating Pattern (CAP) analysis in children with monosymptomatic NE and provide a better understanding of the neurophysiological basis of EN. Methods: After IRB approval, 36 children, 22 with NE and 14 controls aged between seven and 17 years old who met the inclusion criteria were submitted to clinical and laboratory screening, evaluated for aspects of sleep, using sleep logs, Berlin Questionnaire (BQ), Sleep Scale for Children (SDSC) and Epworth Sleepiness Scale (ESS) and submitted to a full polysomnographic study, with evaluation of CAP. Results: ESS and BQ evidenced no abnormalities, the SDSC showed mild sleep apnea in 11/22 (50%), hyperhidrosis in 2/22 (9%) and disorder of the sleep-wake transition, awakening and initiation and maintenance sleep in 1/22 (4.5%) each. Analysis of sleep macrostructure showed higher numbers of awakenings (p < 0.001) and N2 sleep (p = 0.0025) as well as greater amount of sleep N3 (p < 0.0001) when compared to controls. Sleep microstructure showed an increase in A1 phase (p = 0.05), and reduction of A2 and A3 (p < 0.0001). CAP rate was the same for both enuretic and controls. Conclusion: Children with EN may present sleep comorbidities (measured by SDSC) and less A2 and A3 CAP phases, meaning a reduction in its wake regulation. This is the first study to acknowledge this phenomenon

Nesta dissertação, estudamos cadeias unidimensionais antiferromagnéticas de spins 1/2 modeladas pelo Hamiltoniano de Heisenberg na presença de inomogeneidades causadas principalmente pela introdução de ligações substitucionais (defeitos nas ligações) e por efeitos de borda. Interessados então em determinar a energia do estado fundamental de sistemas com quaisquer distribuições das ligações, utilizamos o formalismo da Teoria do Funcional da Densidade (DFT) desenvolvido para o modelo de Heisenberg. O formalismo da DFT permite a estimativa da energia do estado fundamental de sistemas não-homogêneos conhecendo-se o sistema homogêneo. Construímos funcionais na aproximação da ligação local (LBA), proposta recentemente em analogia à já conhecida LSA (aproximação local para o spin). A obtenção dos funcionais se baseou no estudo do modelo de uma cadeia de spins em que as ligações são alternadas, isto é, a interação de troca se alterna em valor de sítio para sítio. Isso originou um funcional não-local na interação de troca da cadeia. Apesar disso, continuamos utilizando a nomenclatura LBA. Todos os resultados fornecidos pelos funcionais são comparados a dados provenientes de diagonalização numérica exata. / In this dissertation, we use the Heisenberg model to describe inhomogeneous antiferromagnetic spin 1/2 chains. The translational invariance is broken mainly due to the non-uniform distribution of bond interactions (defects) and the presence of boundaries. Interested in obtaining the ground-state energy of systems with any distribution of exchange couplings (Jij), we use the density-functional theory (DFT) formalism, developed for the Heisenberg model. The DFT formalism allows an estimate of the ground-state energy of inhomogeneous systems based on the homogeneous systems. We build functionals for the ground-state energy using a local bond approximation (LBA), recently proposed in analogy to the already known LSA (local spin approximation). To obtain the functionals we studied a model that describes an alternating chain, in which the exchange coupling alternates from site-to-site. This resulted in non-local functionals on the spin-spin exchange interaction. Nevertheless, we still call them LBA functionals. All the results from the functionals are compared with exact numerical data.

Introdução: A enurese noturna (EN) é considerada como a eliminação de urina no período noturno, de forma involuntária, em indivíduos com cinco ou mais anos de idade em pelo menos duas noites no mês até todas as noites. EN pode ser do tipo monossintomática, quando ocorre na ausência de outros sintomas, ou não monossintomática, na presença de sintomas de vesicais diurnos. Apesar de historicamente conhecida com uma desordem psiquiátrica, a EN monossintomática está incluída na Classificação Internacional dos Transtornos de 2012 como uma parassonia podendo ocorrer em qualquer fase do sono, porém predominantemente no sono não REM. Está comumente associada a hiperatividade vesical, produção excessiva de urina e falha em acordar após o enchimento vesical. Apesar de ocorrer no sono, a avaliação do sono pelos padrões usuais falhou em encontrar justificativa para este processo patológico. A análise da microestrutura do sono é uma ferramenta mais refinada e precisa que pode auxiliar na busca do mecanismo neurofisiológico que justifica este processo. Objetivo: Analisar os padrões de microarquitetura de sono atrvés do Padrão alternante Cíclico (CAP) nas crianças com EN monossintomática para melhor compreensão das bases neurofisiológicas da EN. Metodologia: Trinta e seis crianças sendo, 22 enuréticos e 14 controles com idade variando entre sete e 17 anos de idade, que satisfizeram os critérios de inclusão, foram submetidas a triagem clínica e laboratorial, avaliados quanto aos aspectos do sono, com uso de diários de sono, das escalas de Berlin, Sleep Scale for Children (SDSC) e Escala de Sonolência de Epworth e posteriormente submetidos ao de estudo polissonográfico completo de noite inteira, com a avaliação do CAP. Resultados: As escalas de sonolência e de Berlin não evidenciaram anormalidades, o SDSC evidenciou apneia em 11/22 (50%), hiperidrose em 2/22 (9%) e transtorno da transição vigília-sono, do despertar e do início e manutenção de sono em 1/22 (4,5%) cada. A análise da estrutura do sono mostrou maiores números de despertares (p < 0,001) e de sono N2 (p=0,0025) além de maior quantidade de sono N3 (p < 0,0001) do que nos controles. A microestrutura do sono evidenciou aumento da fase A1 (p=0,05), porém de forma mais contundente, redução das fases A2 e A3 (p < 0,0001), mesmo com a taxa de CAP igual à dos controles normais.Conclusão: Crianças com EN possuem sono com comorbidades (avaliado pelo SDSC) e menos fases CAP A2 e A3, significando uma redução no seu mecanismo de despertar e que ainda não havia sido demonstrado num estudo de PSG com análise das variáveis comuns. Este é o primeiro estudo que demonstra tal fenômeno / Introduction: Nocturnal enuresis (NE) is defined as the lack of nocturnal urine control, in individuals with five or more years old for at least two nights in a month, but up to every night. EN can be monosymptomatic (ENM), when it occurs in the absence of other symptoms or non monosymptomatic in the presence of diurnal renal symptoms. Although historically known as a psychiatric disorder, ENM is included in the International Classification of Sleep Disorders 2012 as a parasomnia. It can occur at any sleep stage but predominantly in non-REM sleep. EN is commonly associated to bladder hyperactivity, excessive urine production and/or failure to wake up after bladder filling. Despite the occurrence in sleep, standard sleep evaluation has failed to find abnormalities. The analysis of sleep microstructure is a refined and more accurate tool that can help find the neurophysiological mechanism underlying this process. Purpose: To evaluate sleep microarchitecture through Clyclic Altenating Pattern (CAP) analysis in children with monosymptomatic NE and provide a better understanding of the neurophysiological basis of EN. Methods: After IRB approval, 36 children, 22 with NE and 14 controls aged between seven and 17 years old who met the inclusion criteria were submitted to clinical and laboratory screening, evaluated for aspects of sleep, using sleep logs, Berlin Questionnaire (BQ), Sleep Scale for Children (SDSC) and Epworth Sleepiness Scale (ESS) and submitted to a full polysomnographic study, with evaluation of CAP. Results: ESS and BQ evidenced no abnormalities, the SDSC showed mild sleep apnea in 11/22 (50%), hyperhidrosis in 2/22 (9%) and disorder of the sleep-wake transition, awakening and initiation and maintenance sleep in 1/22 (4.5%) each. Analysis of sleep macrostructure showed higher numbers of awakenings (p < 0.001) and N2 sleep (p = 0.0025) as well as greater amount of sleep N3 (p < 0.0001) when compared to controls. Sleep microstructure showed an increase in A1 phase (p = 0.05), and reduction of A2 and A3 (p < 0.0001). CAP rate was the same for both enuretic and controls. Conclusion: Children with EN may present sleep comorbidities (measured by SDSC) and less A2 and A3 CAP phases, meaning a reduction in its wake regulation. This is the first study to acknowledge this phenomenon

We consider discrete and continuous symmetric random variables X taking values in [0; 1], and thus having expected value 1/2. The main thrust of this investigation is to study the correlation between the variance, Var(X) of X and the value of the expected maximum E(Mn) = E(X1,...,Xn) of n independent and identically distributed random variables X1,X2,...,Xn, each distributed as X. Many special cases are studied, some leading to very interesting alternating sums, and some progress is made towards a general theory.

<p>This thesis is about a generalization of permutation theory. The concept of pattern avoidance in permutation matrices is investigated in a larger class of matrices - the alternating sign matrices. The main result is that the set of alternating sign matrices avoiding the pattern 132, is counted by the large Schröder numbers. An algebraic and a bijective proof is presented. Another class is shown to be counted by every second Fibonacci number. Further research in this new area of combinatorics is discussed.</p>