Neste trabalho são discutidos os procedimentos simplificados para a consideração da não linearidade física (NLF) e da não linearidade geométrica (NLG) na análise de edifícios de concreto armado. Deste modo, pretende-se estabelecer o grau de confiabilidade desses processos. Algumas prescrições para redução na inércia dos elementos estruturais são comparadas com os resultados obtidos através de modelos em elementos finitos, permitindo, assim, a avaliação destas prescrições. Um estudo detalhado do parâmetro &#947z, como majorador dos esforços em primeira ordem para a obtenção dos esforços finais em segunda ordem, é efetuada, de modo que se possa estabelecer, de forma mais clara, as vantagens e as limitações deste parâmetro. / This work shows some simplified procedures to consider physical non-linearity (FNL) and geometrical non-linearity (GNL), for reinforced concrete buildings, and discusses its reliability. For FNL, prescriptions for stiffness reduction of structural elements are compared with the results obtained from finite elements analysis, in order to verify its assessment. For GNL, a detailed study of the accuracy of &#947z parameter to evaluate final second order effects is made. The behavior of the parameter along the height of the building and for each effort considered is shown.

Participation in the European Parliament Election has steadily declined since the start in 1979. In 2004 less than half (47.8%) of the voting-age population of the European Union used their right to vote. This has actualized questions asking if the European Parliament is a good representation of the European citizens. The paradigm when it comes to explaining the electoral turnout in the European Parliament Election is the second-order theory. Though the theory explains the low voter participation, it does not explain why the European Parliament Election has become a second-order election. Thus, in this thesis will search for the underlying variable explaining why the European Parliament Election is a second-order election. Through our research we find that distances are important in the European Union, and they create centres and peripheries within the European Union. By looking at Rokkan and Urwin‟s horizontal and vertical types of peripheries, where the vertical type consists of Rokkan and Urwin‟s three domain of social life, our research concludes that centre-periphery structures within the European Union are the underlying variable, explaining why the European Parliament Election is a second-order election.

The provision of leisure and recreation has the potential to vitalise and change lower socio-economic communities. The benefits of leisure and recreation participation are, however, absent in the lower socio-economic communities of Danville and Elandspoort, as recreation and leisure activities are not seen as necessary needs that should be provided for the residents. Lower socio-economic status communities tend to suffer as a consequence of the often subliminal assumptions and reactions of well-meaning people. A major barrier to the implementation of recreation programmes in lower socio-economic communities remains the fact that these programmes often fall into the ambit of non-profit organisations, whose first priority does not usually include recreation provision. Second-order cybernetics theory is introduced in this study as a possible alternative approach to recreation provision in lower socio-economic communities. Engaging in a second-order cybernetics approach, the recreation provider can look beyond the feedback patterns utilised by a community to maintain its status quo, and work with and within a community to establish a sustainable recreation programme. Through the use of a second-order cybernetics approach, the residents of a lower socio-economic status community will no longer be regarded as the ‘observed’ participants of a programme that has been designed by an ‘observer’ and ‘expert’ recreation provider, but will, rather, participate in and share the responsibility of designing their own recreation programme for the community. The following three hypotheses were formulated:<ul> <li>Recreation provision in lower socio-economic communities will benefit from a second-order cybernetics approach.</li> <li>Sustainable recreation provision in a lower socio-economic status community will enhance the quality of life of the residents engaging in the activities available within the community.</li> <li>Second-order recreation provision in a lower socio-economic community will create an environment that is likely to be beneficial for social change</li></ul> In order for the hypotheses to be tested, the aims of the study were:<ul> <li>To examine the influence of recreation and leisure opportunities as a means of improving and maintaining social cohesion and quality of life in lower socio-economic status communities.</li> <li>To identify the barriers to providing and maintaining a comprehensive, sustainable recreation programme in a lower socio-economic community.</li> <li>To understand the way in which the residents of Danville and Elandspoort view recreation and recreation provision within the communities.</li> <li>To identify the similarities and differences between the current approach to recreational provision in the lower socio-economic communities of Danville and Elandspoort and a second-order cybernetics approach.</li></ul> Grounded in a qualitative framework, the research methods for the study included a literature review, the use of focus groups and vignette techniques, and observation. The sampling for the focus groups was done by means of convenience sampling. In total, six focus groups, which were segmented by place of attendance, participated. A total of 60 participants were used in the study, excluding the residents to whom the researcher spoke throughout the course of the study, and as part of the observation. It was found that a positive relationship exists between lower socio-economic status and inappropriate recreation programming. Lower socio-economic status communities are excluded from participation by means of several barriers, including factors such as cost of participation, registration fees and transport. An important barrier to recreation participation in the lower socio-economic status communities of Danville and Elandspoort that was identified in the study was the absence of recreation facilities in the communities. Residents confirmed that television and the consumption of alcohol were the main recreation activities in the communities. The responses provided in focus group discussions confirmed the fact that residents felt excluded from society, and that they also assumed that leisure and recreation activities were privileges that were reserved only for the middle and higher socio-economic status communities. Residents within the communities did not only feel excluded from society, but also felt powerless to do something about the situation. In response to the question concerning their perception of quality of life within the communities, participants demonstrated that they felt that recreation programming would be a positive contribution to the communities’ perception of a better quality of life. A second-order approach to recreation provision in the communities of Danville and Elandspoort will assist in facilitating a process of social change within the communities by including residents in the planning and provision of a community recreation programme. In order to utilize the full potential of leisure and recreation provision in the lower socio-economic communities of Danville and Elandspoort, the following aspects are suggested for the undertaking of any further research: <ul> <li>The potential of leisure and recreation provision to facilitate social change in a lower socio-economic community.</li> <li>Real barriers versus perceived barriers to recreation provision and recreation participation in a lower socio-economic community.</li> <li>Second-order cybernetics recreation provision as a community development approach: implementation and evaluation of change and sustainability within the community.</li></ul> AFRIKAANS : Die voorsiening van rekreasie in ‘n lae sosio-ekonomiese status gemeenskap het die inherente vermoë om ‘n positiewe verandering in die gemeenskap te bring. Die voordeel van rekreasie kan egter nie in die lae sosio-ekonomiese status gemeenskappe van Danville en Elandspoort verwesenlik en bydrae tot ‘n hoër persepsie van lewenskwaliteit nie, aangesien rekreasievoorsiening dikwels nie gesien word as ‘n nodige behoefte in die versorging van lae sosio-ekonomiese gemeenskappe nie. Die voorsiening van behoeftes in lae sosio-ekonomiese gemeenskappe val dikwels onder die vaandel van geloofsgroepe (kerke), nie-winsgewende organisasies en vrywilligers wat, alhoewel met goeie bedoelings, dikwels onbewustelik as ‘kenners’ namens die gemeenskap besluite neem. ‘n Tweede-orde kubernetiese benadering tot rekreasievoorsiening word in die studie voorgestel as ‘n moontlike alternatief tot die huidige benadering in lae sosio-ekonomiese status gemeenskappe. Die gebruik van ‘n tweede-orde kubernetiese benadering gee die rekreasievoorsiener die geleentheid om verby die gemeenskap se terugvoer patrone te kyk, en saam met die gemeenskap ‘n volhoubare rekreasieprogram te ontwikkel. ‘n Tweede-orde kubernetiese benadering tot rekreasie voorsiening verander die posisie van die gemeenskapslede van ‘geobserveerde’ deelnemers aan ‘n rekreasie program ontwerp deur ‘n ‘observerende’ rekreasiekundige, na ‘n deelnemende rol in die ontwerp van die rekreasie program vir die gemeenskap. Die volgende drie hipoteses is geformuleer in antwoord op die navorsings probleem: <ul> <li>Rekreasie voorsiening in lae sosio-ekonomiese gemeenskappe sal positief beïnvloed word deur ‘n tweede-orde kubernetiese benadering.</li> <li>‘n Volhoubare rekreasie program en geleenthede vir rekreasie deelname in die lae sosio-ekonomiese gemeenskappe van Danville en Elandspoort sal die gemeenskap se persepsie van lewenskwaliteit verhoog.</li> <li>‘n Rekreasie program met ‘n tweede-orde kubernetiese benadering in ‘n lae sosio-ekonomiese gemeenskap sal bydrae tot ‘n omgewing ontvanklik vir sosiale verandering.</li> </ul> Die doelwitte gestel vanuit die hipoteses is as volg: <ul> <li>Om die invloed van rekreasie en vryetyds-besteding geleenthede op die sosiale samehorigheid en handhawing van ‘n positiewe persepsie van lewenskwaliteit in die lae sosio-ekonomies gemeenskappe van Danville en Elandspoort te ondersoek;</li> <li>Om die struikelblokke tot die aanbied van ‘n volhoubare rekreasieprogram in ‘n lae sosio-ekonomies gemeenskap te identifiseer;</li> <li>Om te verstaan hoe die inwoners van die lae sosio-ekonomiese gemeenskappe van Danville en Elandspoort rekreasie voorsiening in die gemeenskap sien en ervaar;</li> <li>Om ooreenkomste asook verskille tussen die huidige benadering tot rekreasie voorsiening in die gemeenskap, en ‘n moontlike tweede-orde kubernetiese benadering te identifiseer.</li> </ul> Navorsing in die studie is kwalitatief en navorsingsmetodes sluit in ‘n literatuurstudie, fokus groepe, vignette tegniek, informele onderhoud en observasie. Selektering vir die fokus groepe is gedoen deur gerieflikheids-selektering, met indeling volgens die plek van bywoning: twee sopkombuise in Elandspoort, ‘n sopkombuis in Danville en ‘n ma-en-baba sentrum in Danville. ‘n Totaal van sestig deelnemers is gebruik in die studie, uitgesluit die gemeenskapslede met wie die navorser gepraat het deur die verloop van die studie. ‘n Positiewe verhouding is gevind tussen lae sosio-ekonomies status en swak rekreasie voorsiening. Lae sosio-ekonomiese gemeenskappe word uitgesluit deur die bestaan van verskeie struikelblokke tot deelname aan rekreasie, insluitend koste van deelname, registrasiefooie en vervoerprobleme. ‘n Belangrike struikelblok tot deelname aan rekreasie geidentifiseer in die studie is die afwesigheid van rekreasie fasiliteite in die gemeenskap. Inwoners het bevestig dat televisie en verbruik van alkohol die belangrikste vorm van rekreasie in die gemeenskap is. Reaksies van deelnemers aan die fokusgroepe het bevestig dat inwoners uitgesluit voel van die samelewing, en dat die aanname binne die gemeenskap bestaan dat rekreasie en vryetyd-aktiwiteite die voorreg van middel en hoër sosio-ekonomiese status gemeenskappe is. In reaksie op inwoners se lewenskwaliteit is daar deur die deelnemers aangedui dat rekreasie aktiwiteite in die gemeenskap sal bydrae tot ‘n positiewe persepsie van lewenskwaliteit. Om die volle potensiaal van rekreasie voorsiening in die gemeenskap van Danville en Elandspoort tot reg te laat kom, word die volgende aanbevelings gemaak ten opsigte van verdere navorsing: <ul> <li>Die potensiaal van rekreasie en vryetydsbestuur in die fasiliteitering van sosiale verandering in ‘n lae sosio-ekonomiese gemeenskap.</li> <li>Werklike struikelblokke teenoor die ‘persepsie’ van struikelblokke in ‘n lae sosio-ekonomiese gemeenskap.</li> <li>Implementering van ‘n tweede-orde kubernetiese rekreasie program in ‘n lae sosio-ekonomiese status gemeenskap.</li> </ul> / Dissertation (MA)--University of Pretoria, 2010. / Biokinetics, Sport and Leisure Sciences / unrestricted

In this dissertation, we introduce a novel text representation method mainly used for text classification purpose. The presented representation method is initially based on a variety of closeness relationships between pairs of words in text passages within the entire corpus. This representation is then used as the basis for our multi-level lightweight ontological representation method (TOR-FUSE), in which documents are represented based on their contexts and the goal of the learning task. The method is unlike the traditional representation methods, in which all the documents are represented solely based on the constituent words of the documents, and are totally isolated from the goal that they are represented for. We believe choosing the correct granularity of representation features is an important aspect of text classification. Interpreting data in a more general dimensional space, with fewer dimensions, can convey more discriminative knowledge and decrease the level of learning perplexity. The multi-level model allows data interpretation in a more conceptual space, rather than only containing scattered words occurring in texts. It aims to perform the extraction of the knowledge tailored for the classification task by automatic creation of a lightweight ontological hierarchy of representations. In the last step, we will train a tailored ensemble learner over a stack of representations at different conceptual granularities. The final result is a mapping and a weighting of the targeted concept of the original learning task, over a stack of representations and granular conceptual elements of its different levels (hierarchical mapping instead of linear mapping over a vector). Finally the entire algorithm is applied to a variety of general text classification tasks, and the performance is evaluated in comparison with well-known algorithms.

Cette thèse développe des techniques à base d'automates pour la vérification formelle de systèmes physiquement distribués communiquant via des canaux fiables de tailles non bornées. Chaque machine peut exécuter localement plusieurs programmes récursifs (multi-threading). Un programme récursif peut également utiliser pour ses calculs locaux des structures de données non bornées, comme des files ou des piles. Ces systèmes, utilisés en pratique, sont si puissants que tous leurs problèmes de vérification deviennent indécidables. Nous introduisons et étudions un nouveau paramètre, appelé largeur de coupe (split-width), pour l'analyse de ces systèmes. Cette largeur de coupe est définie comme le nombre minimum de scissions nécessaires pour partitioner le graphe d'une exécution en parties sur lesquelles on pourra raisonner de manière indépendante. L'analyse est ainsi réalisée avec une approche diviser pour régner. Lorsqu'on se restreint à la classe des comportements ayant une largeur de coupe bornée par une constante, on obtient des procédures de décision optimales pour divers problèmes de vérification sur ces systèmes tels que l'accessibilité, l'inclusion, etc. ainsi que pour la satisfaisabilité et le model checking par rapport à divers formalismes comme la logique monadique du second ordre, la logique dynamique propositionnelle et des logiques temporelles. On montre aussi que les comportements d'un système ont une largeur de coupe bornée si et seulement si ils ont une largeur de clique bornée. Ainsi, grâce aux résultats de Courcelle sur les graphes de degré uniformément borné, la largeur de coupe est non seulement suffisante, mais aussi nécessaire pour obtenir la décidabilité du problème de satisfaisabilité d'une formule de la logique monadique du second ordre. Nous étudions ensuite l'existence de contrôleurs distribués génériques pour nos systèmes distribués. Nous proposons plusieurs contrôleurs, certains ayant un nombre fini d'états et d'autres étant déterministes, qui assurent que les comportements du système sont des graphes ayant une largeur de coupe bornée. Un système ainsi contrôlé de manière distribuée hérite des procédures de décision optimales pour les différents problèmes de vérification lorsque la largeur de coupe est bornée. Cette classe décidable de système généralise plusieurs sous-classes décidables étudiées précédemment. / This thesis investigates automata-theoretic techniques for the verification of physically distributed machines communicating via unbounded reliable channels. Each of these machines may run several recursive programs (multi-threading). A recursive program may also use several unbounded stack and queue data-structures for its local-computation needs. Such real-world systems are so powerful that all verification problems become undecidable. We introduce and study a new parameter called split-width for the under-approximate analysis of such systems. Split-width is the minimum number of splits required in the behaviour graphs to obtain disjoint parts which can be reasoned about independently. Thus it provides a divide-and-conquer approach for their analysis. With the parameter split-width, we obtain optimal decision procedures for various verification problems on these systems like reachability, inclusion, etc. and also for satisfiability and model checking against various logical formalisms such as monadic second-order logic, propositional dynamic logic and temporal logics. It is shown that behaviours of a system have bounded split-width if and only if they have bounded clique-width. Thus, by Courcelle's results on uniformly bounded-degree graphs, split-width is not only sufficient but also necessary to get decidability for MSO satisfiability checking. We then study the feasibility of distributed controllers for our generic distributed systems. We propose several controllers, some finite state and some deterministic, which ensure that the behaviours of the system have bounded split-width. Such a distributedly controlled system yields decidability for the various verification problems by inheriting the optimal decision procedures for split-width. These also extend or complement many known decidable subclasses of systems studied previously.

Dans cette thèse on s'intéresse aux formes de "circularité" qui apparaissent dans la théorie de la preuve de la logique du second ordre et de son contrepartie constructive, le Système F.Ces "circularités", ou "cercles vicieux" (Poincaré 1900), sont analysées sur la base d'une distinction entre deux points de vue distincts et irréductible (à cause des théorèmes d'incomplétude): le premier ("le pourquoi", Girard 1989) concerne la cohérence et l'Hauptsatz et demande des méthodes infinitaires (i.e. non élémentaires) de preuve. Le deuxième ("le comment", Girard 1989) concerne le contenu computationnel et combinatoire des preuves, donné par la correspondance entre preuves et programmes, et ne demande que de méthodes élémentaires de preuve.Dans la première partie de la thèse, dévouée au "pourquoi", les arguments philosophiques traditionnels sur les "cercles vicieux" sont confrontés avec la perspective qui émerge de la démonstration de l' Hauptsatz pour la logique de second ordre (obtenue par Girard avec la technique des candidats de réductibilité).Dans la deuxième partie de la thèse, dévouée au "comment", deux approches combinatoires aux cercles vicieux sont proposés: la première se basant sur la théorie du polymorphisme paramétrique, la deuxième sur l'analyse géométrique du typage qui vient de la théorie de l'unification. / In this dissertation several issues concerning the proof-theory of second order logic and its constructive counterpart (System F, Girard 1971) are addressed. The leitmotiv of the investigations here presented is the apparent "circularity'' or "impredicativity'' of second order proofs. This circularity is reflected in System F by the possibility to type functions applied to themselves, in contrast with Russell's idea that typing should rather forbid such ``vicious circles'' (Poincare 1906). A fundamental methodological distinction between two irreducible (because of incompleteness) approaches in proof theory constitutes the background of this work: on the one hand, "why-proof theory'' ("le pourquoi'', Girard 1989) addresses coherence and the Hauptsatz and requires non-elementary ("infinitary'') techniques; on the other hand, "how-proof theory'' ("le comment'', Girard 1989) addresses the combinatorial and computational content of proofs, given by the correspondence between proofs and programs, and is developed on the basis of elementary ("finitary'') techniques. }In the first part of the thesis, dedicated to "why-proof theory'', the traditional philosophical arguments on "vicious circles'' are confronted with the perspective arising from the proof of the Hauptsatz for second order logic (first obtained in Girard 1971 with the technique of reducibility candidates).In the second part of the thesis, dedicated to "how-proof theory'', two combinatorial approaches to "vicious circles'' are presented, with some technical results: the first one based on the theory of parametric polymorphism, the second one on the geometrical analysis of typing coming from unification theory.

[pt] Esse trabalho propõe uma implementação numérica para otimização de forma em problemas bi-dimensionais de elasticidade. O objetivo principal é propor uma metodologia eficiente e robusta para solução de problemas de otimização de forma considerando a minimização de concentração de tensões. Na implementação proposta, a análise estrutural é realizada pelo Método dos Elementos de Contorno Simétrico de Galerkin (MECSG), evitando-se assim a dispendiosa etapa de geração da malha. A avaliação das tensões no contorno é obtida por meio de um método preciso, ideal para problemas com concentrações de tensões. Outro aspecto relevante na implementação é a adequada partição das equações do MECSG de forma a reduzir, consideravelmente, o esforço computacional associado à etapa da análise estrutural. O problema de otimização é resolvido utilizando-se um método de otimização moderno, conhecido como Programação Cônica de Segunda Orderm (PCSO). Especificamente, busca-se a reposta do problema de otimização não linear por meio da solução de uma sequência de subproblemas de PCSO. / [en] In this work a numerical implementation of shape optimization in two-dimensional linear elasticity problems is proposed. The main goal is to propose a robust and efficient methodology for the solution of shape optimization problems regarding the minimization of stress concentration effects. In the proposed implementation, the structural analysis is performed by the Symmetric Galerkin Boundary Element Method (SGBEM), thus disposing of the mesh generation burden. The boundary stress evaluation is carried out by an accurate approach which is ideally suited for problems with stress concentrations. Another relevant feature of the proposed implementation is a suitable partition of the SGBEM equations which aims at reducing the computational effort associated with the structural analysis stage. The solution for the optimization problem is obtained by means of a modern numerical optimization method, the so-called Second Order Conic Programming (SOCP). Specifically, the solution for the non-linear optimization is sought by solving a sequence of SOCP subproblems.

This study aims to analyse the impact of Social Media Marketing in Customer Brand Engagement and Brand Awareness micro-learning platforms. The sample consisted of 220 students from micro-learning platforms using social media in the educational institutions. Because social-media marketing and customer brand- engagement are second-order reflexive constructions, the two-stage approach of hierarchical models with mode-A was adopted. The results reveal that social media marketing influences both the building of customer brand engagement and brand awareness among students on micro-learning platforms. Furthermore, it was shown that customer brand engagement is an important mediator between social media marketing and brand awareness. Social-media marketing activities carried out by micro-learning platforms contribute to the generation of customer brand-engagement and brand awareness of these institutions. Furthermore, the results show that, although social-media marketing helps to generate brand-awareness, it is through customer brand-engagement that social-media marketing is most effective in generating brand-awareness. For micro-learning platforms, the results allow them to understand the importance of customer brand-engagement when using social-media marketing to generate brand-awareness.

Cílem této diplomové práce je sjednotit a zobecnit známé výsledky z literatury, studovat asymptotické chování kladných regulárně se měnících řešení jisté třídy nelineárních diferenciálních rovnic (tzv. skoro pololineárních diferenciálních rovnic) pomocí dostupných nástrojů. Tato práce zahrnuje popis teorie regulární variace, některé informace o nelineárních diferenciálních rovnicích různých typů, detailní odvození výsledků týkajících se asymptotického chování řešení a příklady aplikace získaných výsledků.

The aim of this thesis is to undertake simplified design and assessment of cofferdam under vertical surcharge in the form of virtual project. Cofferdam constructed on the sea shore must be able to withstand all loads to enable construction of cut and cover tunnel. As a part of the design it is required to assess ground conditions and it is necessary to review feasibility of the structure on the sea. The construction will be described in construction phases and graphically demonstrated in construction sequence drawing. Because the structure is designed for life time of five years, temperature load on struts is studied in the thesis and further considered in structural analysis. Furthermore, it is required to compare analytical models from GEO5 and PLAXIS. Horizontal frame is analysed separately in Scia Engineer. Structural members – cofferdam wall, waler beam and strut are checked in this thesis. For the design of the cofferdam wall second order theory is considered. All mentioned requirements were accomplished with help of corresponding Eurocodes, books and technical advice. Results of this work are feasible and it was possible to design all members to enable construction of the cut and cover tunnel. The phasing was designed such that deformation of the cofferdam is minimalized and use of machinery is limited to machines on temporary platforms. Comparison of two different analytical models showed that different soil modelling has great effect on internal forces, even though the shape of the bending curve is very similar, values obtained from PLAXIS software are much higher. Assessment of the structural members is done according to Eurocode 3, and horizontal frame is checked also against disproportionate collapse.