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Behaviourists and Logical Positivists commendably set out to purge prejudiced arguments from science, but where it is obvious that there remains some sort of "ghost" in their rational "machine", it is self-defeating simply to ignore its existence. Freaud, Piaget, and the ethologists have made some progress in grasping this nettle -- moving towards a material explanation of the "other-worldly" properties of the individual -- but their models of the individual remain nebulously structured in their basic elements. Consequently such theories remain disturbingly controversial, and circumscribed in their applicability. [#] The present work accordingly sets out to bridge this gap by postulating plausible functions for existing micro-structure which could account both for observed behavioural phenomena, and for many of the existing vaguer theoretical constructs. Part A develops such an explanation for Piagetian constructs, while Part B fills in some of the technical details concerning quantitative problems of signal generation, transmission, and selective reception. [#] Part C applies these notions to other non-Piagetian descriptions and interpretations of psychological phenomena, thereby offering an integration and reconciliation of various schools of theory. (Major areas considered include Ashby's "homeostat" approach, biological self-organization, sleep-modes and dreaming, Freudian theories of neuroses, and various theories concerning psychosis). The basic theory itself is meanwhile developed in much greater detail. [#] A recurring theme throughout the work is the notion that knowledge-acquisition by any independent system depends not only on "external" interaction with the "real" world, but also on an active seeking for internal consistency within the resulting "internal" model. This concept is crucial to the study in two ways:- (i) The operation of the brain-systems being considered, and (ii) As a guuide to the methodology of the present study itself -- in an area where experimental data is uncomfortably sparse, and likely to remain so.

Ground penetrating radar (GPR) has been used as a railway substructure investigation tool since the late 1990’s and has seen significant development since then. To use GPR as a more effective tool for substructure investigation, a GPR substructure characterization model was developed. This dissertation provides a detailed description of railway track components, track geometry, soil properties and classification and substructure design. The historical background of GPR is discussed together with GPR principles, basic GPR equations, hardware and accessories as well as GPR data collection, processing and interpretation. Other in situ investigation techniques namely the dynamic cone penetrometer (DCP), light weight deflectometer (LWD) , Pencel pressuremeter, surface wave testing, remote video monitoring (RVM), multi-depth deflectometers (MDD) and continuous track modulus measurement techniques are also discussed. A comparison between the different track investigation techniques was also done, with reference to sample rate, cost, effectiveness and value. Two sites in South Africa were selected for the investigation, one with good substructure conditions used for heavy haul coal export close to Vryheid (KN test section) and the other a general freight line with poor substructure conditions near Rustenburg (NT test section). These two sites were selected to develop a GPR substructure characterization model as they provided conditions ranging from poor to very good. This was supported by the analysis of the in situ soil sampling and testing. The calculation of the track substructure modulus from RVM deflection measurements showed three times higher values for the KN test section compared to the NT test section. The subballast and subgrade thickness, the GPR ballast fouling (GBF) index as well as the GPR moisture condition index was used for the classification ranges used in the model. The subballast and subgrade layer roughness values were calculated and used for the substructure classification. The GBF index and the GPR moisture condition roughness were used for the GPR fouling index classification. The GPR deliverables were divided into four classes (i.e. very good, good, moderate and poor). The evaluation of the characterization model showed that a traditional in situ investigation will cost approximately 3.7 times more than that of a GPR investigation. It would also take two thirds of the time to complete the GPR investigation compared to the traditional in situ investigation. The study showed that GPR can be used to develop a substructure characterization model and that it would be more cost effective and efficient than traditional in situ investigation techniques. GPR surveys provide continuous measurements of the track structure condition and can therefore provide a continuous classification unlike the discreet and fragmented nature of in situ investigations. However, in situ tests can be done at certain intervals within the GPR survey or at point where the GPR classification is not clear. The best solution for railway track characterization can therefore be obtained by using GPR and in situ classification in combination. / Dissertation (MEng)--University of Pretoria, 2012. / Civil Engineering / unrestricted

Seismic isolation is a method of earthquake resistant design which has been proven to effectively reduce the damaging effects of earthquakes on buildings as well as the contents within them. However, traditional implementation of an isolation system tends to be expensive. For new construction, rigid diaphragms above and below the isolation layer and construction of a seismic gap contribute to expenses, while retrofit applications also require excavation beneath the building and may need extensive foundation work. To mitigate these major costs bearings may be placed on the tops of columns, forgoing the construction of a seismic gap, additional rigid diaphragm, and foundation work. However, columns under the isolation layer may be flexible, changing the bearing end conditions traditionally assumed. To investigate the effects of flexible end conditions on elastomeric bearings, an analytical model that accounts for translation and rotation of both endplates was developed based on Haringx's theory. The derivation accounts for compressibility of the rubber and results in a simple stiffness matrix. To evaluate the model, an experimental program testing column-bearing subassemblies under quasi-static cyclic conditions was conducted. Experimental findings show that flexible end conditions can significantly reduce the lateral stiffness of elastomeric bearings. Simulations with the theoretical model compare well under small deformations, but elastic softening of the moment-rotation relationship causes theoretical results to diverge from experimental with larger endplate rotations. The effectiveness of column-top isolation as a retrofit strategy was investigated through nonlinear time history analyses of a moment resisting frame designed to the 1965 National Building Code of Canada and retrofitted with column-top isolation. The frame was simulated under ground motions representative of current hazards and showed that the retrofit resulted in significant reductions in interstory drifts and floor accelerations. Yielding was observed throughout the original frame under maximum considered earthquakes, while the retrofit frame remained elastic. / Thesis / Master of Applied Science (MASc)

Neste trabalho estudou-se a fenomenologia da observação de novos bósons vetoriais com massa da ordem de 1 TeV no LHC. Em particular, a análise foi feita para um bóson vetorial neutro que se acopla com os bósons carregados do Modelo Padrão e esses bósons decaem hadronicamente deixando uma assinatura com jatos no detector. Esse tipo de sinal possui um enorme fundo de QCD devido ao ambiente hadrônico intrínseco ao LHC, de maneira que o uso de técnicas de análise de subestrutura de jatos se tornam indispensáveis. A motivação do trabalho vem dos modelos com dimensões extras curvas que possuem torres de Kaluza-Klein de novos bósons de gauge. Estes são responsáveis por garantir a unitariedade nos espalhamentos dos bósons vetoriais do MP, estudamos em especial a primeira excitação do \'Z POT. 0\', o bóson \'Z POT. 1\'. Na análise fenomenológica vericamos que o LHC possui um grande potencial de descoberta e exclusão dessas classes de modelos além do MP. Para tanto estudamos o sinal pp -> \'Z POT. 1\' -> WW -> jatos e os processos do MP do tipo pp -> jatos, com pelo menos dois jatos na janela de massa do W. Vericamos que para um \'Z POT. 1\' de largura \'M IND. z \'IND. 1\'/10, com massa da ordem de 1 TeV e acoplamentos da ordem de \'10 POT. 3\' vezes menores que os acoplamentos do MP é possível observá-lo no LHC com 30 \'fb IND. -1\' de luminosidade integrada com 14 TeV de energia no centro de massa. / In this work we present a phenomenological study of the observation of new vector bosons with mass around 1 TeV at the LHC. We analyse a neutral vector boson that couples to the charged bosons of the Standard Model and this bosons decay hadronically leaving a multiple jets signature on the detector. This kind of signal has an enormous QCD background due to the hadronic enviroment of the LHC, making the analysis of jet substruture indispensable. The motivation for this work comes from warped extra dimensions models, wich have Kaluza-Klein towers of new gauge bosons. These are responsable for assuring the unitarity of the vector bosons scatterings in the SM. We studied the first excitation of the Z0 bosons, the Z1 boson. We veried that the LHC has a great potential of discovery or exclusion for this classes of theories beyond the SM. For the analysis, we studied the process pp -> Z1 -> WW -> jets and the background processes of the SM of the type pp -> jets, with at least two jets in the W mass window. We veried that for a Z1 with width MZ1/10 , mass of O(1 TeV) and couplings 10^3 times more weakly than those of the SM, it is possible to observe it in the LHC with 30 fb-1 of integrated luminosity in the 14 TeV run.

Neste trabalho estudou-se a fenomenologia da observação de novos bósons vetoriais com massa da ordem de 1 TeV no LHC. Em particular, a análise foi feita para um bóson vetorial neutro que se acopla com os bósons carregados do Modelo Padrão e esses bósons decaem hadronicamente deixando uma assinatura com jatos no detector. Esse tipo de sinal possui um enorme fundo de QCD devido ao ambiente hadrônico intrínseco ao LHC, de maneira que o uso de técnicas de análise de subestrutura de jatos se tornam indispensáveis. A motivação do trabalho vem dos modelos com dimensões extras curvas que possuem torres de Kaluza-Klein de novos bósons de gauge. Estes são responsáveis por garantir a unitariedade nos espalhamentos dos bósons vetoriais do MP, estudamos em especial a primeira excitação do \'Z POT. 0\', o bóson \'Z POT. 1\'. Na análise fenomenológica vericamos que o LHC possui um grande potencial de descoberta e exclusão dessas classes de modelos além do MP. Para tanto estudamos o sinal pp -> \'Z POT. 1\' -> WW -> jatos e os processos do MP do tipo pp -> jatos, com pelo menos dois jatos na janela de massa do W. Vericamos que para um \'Z POT. 1\' de largura \'M IND. z \'IND. 1\'/10, com massa da ordem de 1 TeV e acoplamentos da ordem de \'10 POT. 3\' vezes menores que os acoplamentos do MP é possível observá-lo no LHC com 30 \'fb IND. -1\' de luminosidade integrada com 14 TeV de energia no centro de massa. / In this work we present a phenomenological study of the observation of new vector bosons with mass around 1 TeV at the LHC. We analyse a neutral vector boson that couples to the charged bosons of the Standard Model and this bosons decay hadronically leaving a multiple jets signature on the detector. This kind of signal has an enormous QCD background due to the hadronic enviroment of the LHC, making the analysis of jet substruture indispensable. The motivation for this work comes from warped extra dimensions models, wich have Kaluza-Klein towers of new gauge bosons. These are responsable for assuring the unitarity of the vector bosons scatterings in the SM. We studied the first excitation of the Z0 bosons, the Z1 boson. We veried that the LHC has a great potential of discovery or exclusion for this classes of theories beyond the SM. For the analysis, we studied the process pp -> Z1 -> WW -> jets and the background processes of the SM of the type pp -> jets, with at least two jets in the W mass window. We veried that for a Z1 with width MZ1/10 , mass of O(1 TeV) and couplings 10^3 times more weakly than those of the SM, it is possible to observe it in the LHC with 30 fb-1 of integrated luminosity in the 14 TeV run.

We extend the application of the substructure synthesis method to more complex structures, and establish a design methodology for base isolation and active control in a distributed model of a building under seismic excitation. Our objective is to show that passive and active control complement each other in such an advantageous manner for the case at hand, that simple devices for both types of control are sufficient to achieve excellent response characteristics with very low control forces. The Rayleigh-Ritz based substructure synthesis method proved to be highly successful in analyzing a structure more complex than the ones previously analyzed with it. Comparing the responses of the hybridly controlled building and the conventional fixed building under El Centro excitation, we conclude that the stresses are reduced by 99.6 %, the base displacement is reduced by 91.7 % and the required control force to achieve this is 1.1 % of the building weight. / Ph. D.

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