Dans les systèmes de communications sans fil, le canal de transmission entre les antennes d’émission et de réception est l’une des principales sources de perturbation pour le signal. Les modulations multiporteuses, telles que l’OFDM (pour orthogonal frequency division multiplexing), sont très robustes contre l’effet des multi-trajets, et permet de retrouver le signal émis avec un faible taux d’erreur, quand elles sont combinées avec un codage canal. L’estimation de canal joue alors un rôle clé dans les performances des systèmes de communications. Dans cette thèse, on étudie des techniques fondées sur les estimateurs LS (pour least square, ou moindres carrés) et MMSE (pour minimum mean square error, ou erreur quadratique moyenne minimum). La technique MMSE est optimale, mais est beaucoup plus complexe que LS, et nécessite la connaissance a priori des moments de second ordre du canal et du bruit. Dans cette présentation, deux méthodes permettant d’atteindre des performances proches de LMMSE en évitant ses inconvénients sont étudiées. Une troisième partie étudie quant à elle les erreurs d’estimation dues aux interpolations. / In wireless communications systems, the transmission channel between the transmitter and the receiver antennas is one of the main sources of disruption for the signal. The multicarrier modulations, such as the orthogonal frequency division multiplexing (OFDM), are very robust against the multipath effect, and allow to recover the transmitted signal with a low error rate, when they are combined with a channel encoding. The channel estimation then plays a key role in the performance of the communications systems. In this PhD thesis, we study techniques based on least square (LS) and minimum mean square error (MMSE) estimators. The MMSE is optimal, but is much more complex than LS, and requires the a priori knowledge of the second order moment of the channel and the noise. In this presentation, two methods that allow to reach a performance close to the one of LMMSE while getting around its drawback are investigated. In another way, a third part of the presentation investigates the errors of estimation due to the interpolations.

Cette recherche vise à comprendre la relation existante entre l’innovation de services et l’internationalisation, à savoir, comment les entreprises obtiennent des avantages compétitifs sur les marchés internationaux grâce à l'innovation dans le secteur des services aux entreprises.Nous avons testé la relation entre l'innovation et la performance internationale, avons évalué l'impact de l'innovation par rapport à d'autres avantages internationaux. Symétriquement, nous avons également vérifié dans quelle mesure le processus d'internationalisation peut être un puissant moteur d'innovation pour les entreprises de services. Après le développement d'un modèle théorique, nous avons procédé à une enquête téléphonique auprès de 807 entreprises de services exportatrices. Les répondants cible de l'enquête étaient des cadres supérieurs de sociétés de services internationalisés en France. 51 réponses exploitables ont été reçues. Les données recueillies ont été analysées par Modélisation des Équations Structurelles (SEM), en utilisant la méthode Partial Least Square. Le modèle testé montre que l'innovation de service a une influence positive sur le développement international et que la compétence internationale, obtenue sur les marchés étrangers, stimule la dynamique de l'innovation dans les entreprises de services. Le modèle proposé met en évidence les capacités de R & D (organisationnelle), relationnelles, les TIC, la compétence internationale, l’innovation de service et l’expérience internationale comme facteurs qui influent les résultats des entreprises internationalisées, ou plus précisément, la performance international. / This research deals with service innovation and internationalization: how firms perform on international markets and get an edge thanks to innovation on service concept or service process. We tested the relationship between innovation and international performance, assessed the impact of innovation compared to other international advantages. Symmetrically, we also checked how far the internationalization process can be a powerful driver of innovation for service firms. After the development of a theoretical model, data were collected from a telephone survey. The target respondents of the survey were senior executives of internationalized service companies in France. Out of the 807 companies which were contacted, 51 usable responses were received. The data collected were analyzed by Structural Equation Modeling (SEM), using the Partial Least Square method. The tested model shows that service innovation has a positive influence on international development and that the international competence, obtained in foreign markets, drives the dynamics of innovation in services company. The model proposed highlights the capabilities for R & D (organizational), relational, ICT, international competence, service and international experience as factors that impact the final results of internationalized companies, or more specifically, the international performance.

Ao contrário da recomendação tradicional do treinamento de força, a proposta do método de pré-exaustão é iniciar a sessão de treino com exercícios monoarticulares e terminar com exercícios multiarticulares. O objetivo deste estudo foi, por meio da EMG, investigar parâmetros temporais e de intensidade da ativação dos músculos peitoral maior (PM), deltóide (DA) e tríceps braquial (TB) que possam fundamentar a aplicação do método de pré-exaustão em 10RM dos exercícios supino e crucifixo. Foram comparados dois protocolos experimentais: P1) método da préexaustão; P2) recomendações tradicionais. A intensidade de ativação baseada no valor RMS, bem como a relação desta com a duração da contração muscular, estabelecida em faixas de intensidade, não obteve diferenças estatisticamente significativas para PM. Para DA, não houve diferenças estatisticamente significativas entre os protocolos na intensidade de ativação quando as repetições foram analisadas em conjunto. Entretanto, quando analisado cada repetição, este músculo apresentou aumento estatisticamente significativo de intensidade de ativação em P1, assim como maior solicitação da faixa de intensidade 80 a 100% CIVM. Para TB, a intensidade de ativação foi significativamente maior em P1 que em P2 para todas as formas de análise. Os resultados mostraram que o aparelho locomotor aumentou a dependência de TB como estratégia alternativa para tentar atingir 10RM do supino em P1. Assim, é possível afirmar que o método de pré-exaustão pode ser eficiente para impor maior estímulo neural sobre pequenos grupos acessórios na execução de um movimento e não sobre o grupo principal o qual se deseja. Entretanto, estes achados suportam que os efeitos do método de pré-exaustão ainda não podem ser afirmados categoricamente. Pois, ao longo da série em P1 não houve aumento significativo na intensidade de ativação de um mesmo músculo, bem como das faixas de intensidade, como houve em P2. Desse modo, é possível afirmar que os músculos, em P1, iniciaram a série em um nível de intensidade mais alto que em P2, pois foram estimulados previamente / Contrariwise the strength training traditional recommendation, the preexhaustion method purposes to begin a training session with monoarticular exercises and to finish it with multiarticular exercises. The aim of this study was, through EMG, to inquire into temporal and activation intensity parameters of pectoralis major (PM), deltoid (DA) and triceps brachii (TB) muscles, which can be used as a basis to bench press and flying 10RM pre-exhaustion method application. It was compared two experimental protocols: P1) pre-exhaustion method; P2) traditional recommendation. The activation intensity, as well its relationship with the muscular contraction duration, established on intensity levels, did not attain significant differences to PM. To DA, there were not differences between the protocols respecting the activation intensity when whole the repetitions were analyzed. However, when each repetition was analyzed, this muscle exhibited significant increasing in activation intensity in P1; as well it showed a more intense solicitation of 80 to 100% MVIC level. To TB, the activation intensity was significant greater in P1 than P2 respecting whole manners to data analysis. The results exhibited that the locomotor apparatus increased the TB dependence as an alternative strategy to try to attain bench press 10RM in P1. Therefore, it is possible to assert that pre-exhaustion method may be efficient to impose largest neural stimuli on small synergists muscular groups during movement execution, but not on the main target muscular group. However, these findings sustain that the pre-exhaustion method effects cannot receive a categorical affirmation, yet. Because, contrariwise the P2, during the P1 bench press set there was not significant increasing in the same muscle activation intensity, as well in the intensity levels. This way, it is possible to assert that, in P1 the muscles began the set in a highest intensity levels than in P2, because they were stimulated previously

In this thesis, we investigate graphs and hypergraphs that have (relaxed) product structures. In the class of graphs, we discuss in detail \\emph{RSP-relations}, a relaxation of relations fulfilling the square property and therefore of the product relation $\\sigma$, that identifies the copies of the prime factors of a graph w.r.t. the Cartesian product. For $K_{2,3}$-free graphs finest RSP-relations can be computed in polynomial-time. In general, however, they are not unique and their number may even grow exponentially. Explicit constructions of such relations in complete and complete bipartite graphs are given. Furthermore, we establish the close connection of (\\emph{well-behaved}) RSP-relations to \\mbox{(quasi-)covers} of graphs and equitable partitions. Thereby, we characterize the existence of non-trivial RSP-relations by means of the existence of spanning subgraphs that yield quasi-covers of the graph under investigation. We show, how equitable partitions on the vertex set of a graph $G$ arise in a natural way from well-behaved RSP-relations on $E(G)$. These partitions in turn give rise to quotient graphs that have rich product structure even if $G$ itself is prime. This product structure of the quotient graph is still retained even for RSP-relations that are not well-behaved. Furthermore, we will see that a (finest) RSP-relation of a product graph can be obtained easily from (finest) RSP-relations on the prime factors w.r.t. certain products and in what manner the quotient graphs of the product w.r.t. such an RSP-relation result from the quotient graphs of the factors and the respective product. In addition, we examine relations on the edge sets of \\emph{hyper}graphs that satisfy the grid property, the hypergraph analog of the square property. We introduce the \\emph{strong} and the \\emph{relaxed} grid property as variations of the grid property, the latter generalizing the relaxed square property. We thereby show, that many, although not all results for graphs and the (relaxed) square property can be transferred to hypergraphs. Similar to the graph case, any equivalence relation $R$ on the edge set of a hypergraph $H$ that satisfies the relaxed grid property induces a partition of the vertex set of $H$ which in turn determines quotient hypergraphs that have non-trivial product structures. Besides, we introduce the notion of \\emph{(Cartesian) hypergraph bundles}, the analog of (Cartesian) graph bundles and point out the connection between the grid property and hypergraph bundles. Finally, we show that every connected thin hypergraph $H$ has a unique prime factorization with respect to the normal and strong (hypergraph) product. Both products coincide with the usual strong \\emph{graph} product whenever $H$ is a graph. We introduce the notion of the Cartesian skeleton of hypergraphs as a natural generalization of the Cartesian skeleton of graphs and prove that it is uniquely defined for thin hypergraphs. Moreover, we show that the Cartesian skeleton of thin hypergraphs and its PFD w.r.t. the strong and the normal product can be computed in polynomial time.

The aim of the presented Diploma Thesis was to develop a new method for the indirect determination of formaldehyde in wood-based products using gas-diffusion microextraction coupled with electrochemical detection on unmodified screen-printed electrodes (MLEM-SPCE). Formaldehyde released from the sample is derivatized using an acetylacetone reagent present in an acceptor solution. The product of derivatization of formaldehyde with acetylacetone is 3,5-diacetyl-1,4-dihydrolutidine (DDL) which forms a selective oxidation voltammetric peak at a potential of 0.4 V. Detection and quantification limits of 0.57 mg kg−1 and 1.89 mg kg−1 , respectively, were obtained, together with intra- and inter-day precision below 10% (as relative standard deviation, RSD). The developed methodology was applied to determine formaldehyde content in seven samples. Similar results were obtained from the European standard method EN 717-3 with a significant reduction of total analysis time. The developed method MLEM-SPCE, which combines the use of a new sample preparation procedure for volatile compounds with the firstly introduced determination of formaldehyde (as the derivative product DDL) on unmodified SPCEs, proves to be a promising alternative for the determination of formaldehyde in wood-based products and other samples.

The subject of thesis is the proposal of a new community center, which will be in addition to the larger socio-cultural hall Facilities also include a city district and all necessary facilities. It appears appropriate to share some space, especially for the two main representative feature, or adding additional functions to the new center has become a real focus of civic, social and community activities. Integral part Solutions will finish outdoor spaces, which would functionally replace the missing central square. More detailed framework construction program is contained in a separate annex assignment.

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Arbetet handlar om vilken algoritm som är bäst för att procedurellt generera terräng. Är Diamond-Square bättre eller sämre än vad Perlin noise när de jämförs på exekveringstid och framkomlighet. Algoritmerna är implementerade i Unity där de körs för att få fram exekveringstid och Flood fill används för att ta reda på framkomligheten. Algoritmerna kördes 1000 gånger var på tre olika kartstorlekar för att få fram ett genomsnitt. Resultatet visar att Diamond-Square är snabbare än vad Perlin noise är men Perlin noise har bättre framkomlighet. / This project deals with which algorithm is best for procedural terrain generation. Is Diamond Square better or worse than Perlin noise when they are compared on execution time and exploration. The algorithms are implemented in Unity, where they are tested to get the execution time and Flood Fill is used to determine exploration. The algorithms were run 1000 times each on three different map sizes to obtain an average. The results show that Diamond Square is faster than Perlin noise is but Perlin noise has better exploration.

Doctor of Philosophy / Department of Statistics / Kun Chen and Weixin Yao / This proposal contains two projects that are related to robust mixture models. In the robust project, we propose a new robust mixture of regression models (Bai et al., 2012). The existing methods for tting mixture regression models assume a normal distribution for error and then estimate the regression param- eters by the maximum likelihood estimate (MLE). In this project, we demonstrate that the MLE, like the least squares estimate, is sensitive to outliers and heavy-tailed error distributions. We propose a robust estimation procedure and an EM-type algorithm to estimate the mixture regression models. Using a Monte Carlo simulation study, we demonstrate that the proposed new estimation method is robust and works much better than the MLE when there are outliers or the error distribution has heavy tails. In addition, the proposed robust method works comparably to the MLE when there are no outliers and the error is normal. In the second project, we propose a new robust mixture of linear mixed-effects models. The traditional mixture model with multiple linear mixed effects, assuming Gaussian distribution for random and error parts, is sensitive to outliers. We will propose a mixture of multiple linear mixed t-distributions to robustify the estimation procedure. An EM algorithm is provided to and the MLE under the assumption of t- distributions for error terms and random mixed effects. Furthermore, we propose to adaptively choose the degrees of freedom for the t-distribution using profile likelihood. In the simulation study, we demonstrate that our proposed model works comparably to the traditional estimation method when there are no outliers and the errors and random mixed effects are normally distributed, but works much better if there are outliers or the distributions of the errors and random mixed effects have heavy tails.

International Telemetering Conference Proceedings / October 21, 2002 / Town & Country Hotel and Conference Center, San Diego, California / As frequency allocation restrictions are tightening, and data rates are increasing, it is becoming necessary to incorporate higher order modulation techniques to make more efficient use of available spectrum. When used with Square Root Raised Cosine filtering, 8-ary Phase Shift Keyed modulation is a spectrally efficient technique that makes better use of today’s RF spectrum in comparison to standard formats. This paper will discuss 8-ary PSK modulation and its spectral efficiency with a SRRC filter, along with comparisons to BPSK, QPSK, and FSK.