Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.

La Universidad Peruana de Ciencias Aplicadas (UPC) fue sede de la segunda edición del “University Premium Training” organizada por Bloomberg, empresa líder en información financiera y económica a nivel mundial. / El evento, que fue realizado los días 5, 6 y 7 de noviembre en el campus San Isidro, tuvo como objetivo poder reforzar las competencias de los docentes de diversas universidades de Lima que emplean Bloomberg como una herramienta didáctica para la educación y planificación financiera. Esta compañía brinda herramientas de software financiero, como análisis, plataformas de comercio capital y servicios de datos para las empresas quienes deseen consultar información bursátil y financiera en tiempo real. / Además, se contó con la participación de expertos que emplean la herramienta como apoyo para la toma de decisión financiero: Lizzette Lara; especialista en riesgos y derivados, André Lapponi; especialista Senior en Portafolio y Análisis técnico, Pedro Cortejo, CEO-Founder de Decision Capital, entre otros. / Se explica el análisis de las últimas crisis en USA, la estrategia de Warren Buffet, la selección de acciones y portafolio. Ponente: André Lapponi, especialista senior en portafolios y análisis técnico – Bloomberg.

I följande uppsats har jag skrivit om Saint-Saëns fagottsonat i G-dur, Op.168 och min relation till verket. Arbetet innehåller en studie av kompositörens liv kring tiden då styckets skrevs. Jag har använt olika analysmetoder och valt att analysera stycket ur flera perspektiv, detta för att få en djupare insikt och mer verktyg att arbeta med under min instuderingsprocess. Här får vi en generell analys över verket samt en djupgående mer teoretisk analys av sonatens första sats. I arbetet har jag även studerat fagottens historia och analyserat skillnaderna mellan fagottens uppbyggnad under tiden stycket skrevs i förhållande till dagens moderna fagotter. För att förtydliga detta har jag även valt att analysera två olika tolkningar av stycket, där exekutörerna spelar på fagotter med helt olika konstruktioner. Ett stort fokus ligger även på analysen kring min egen instuderningsprocess där jag tar upp svårigheter, hinder och mitt tillvägagångssätt.

An artificial Neural Network (ANN) system has been developed that can analyse aircraft flight data to provide a reconstruction of the aerodynamic loads experienced by the aircraft during flight, including manoeuvre, buffet and distributed loading. For this research data was taken from the International Follow-On Structural Test Project (IFOSTP) F/A-18 fatigue test conducted by the Royal Australian Air Force and Canadian Forces. This fatigue test involved the simultaneous application of both manouevre and buffet loads using airbag actuators and shakers. The applied loads were representative of the actual loads experienced by an FA/18 during flight tests. Following an evaluation of different ANN types an Ellman network with three linear layers was selected. The Elman back-propagation network was tested with various parameters and structures. The network was trained using the MATLAB 'traingdx' function with is a gradient descent with momentum and adaptive learning rate back-propagation algorithm. The ANN was able to provide a good approximation of the actual manoeuvre or buffet loads at the location where the training loads data were recorded even for input values which differ from the training input values. In further tests the ability to estimate distributed loading at locations not included in the training data was also demonstrated. The ANN was then modified to incorporate various methods for the calculation and prediction of output error and reliability Used in combination and in appropriate circumstances, the addition of these capabilities significantly increase the reliability, accuracy and therefore usefulness of the ANN system's ability to estimate aircraft loading.To demonstrate the ANN system's usefulness as a fatigue monitoring tool it was combined with a formulae for crack growth analysis. Results inficate the ANN system may be a useful fatigue monitoring tool enabling real time monitoring of aircraft critical components using existing strain gauge sensors.

<p>This thesis presents the work done to implement new computational tools and methods dedicated to aircraft conceptual design sizing and optimization. These tools have been exercised on different aircraft concepts in order to validate them and assess their relevance and applicability to practical cases.First, a geometry construction protocol has been developed. It is indeed essential to have a geometry description that supports the derivation of all discretizations and idealizations used by the different analysis modules (aerodynamics, weights and balance, stability and control, etc.) for which an aircraft concept is evaluated. The geometry should also be intuitive to the user, general enough to describe a wide array of morphologies and suitable for optimization. All these conditions are fulfilled by an appropriate parameterization of the geometry. In addition, a tool named CADac (Computer Aided Design aircraft) has been created in order to produce automatically a closed and consistent CAD solid model of the designs under study. The produced CAD model is easily meshable and therefore high-fidelity Computational Fluid Dynamics (CFD) computations can be performed effortlessly without need for tedious and time-consuming post-CAD geometry repair.Second, an unsteady vortex-lattice method based on TORNADO has been implemented in order to enlarge to scope of flight conditions that can be analyzed. It has been validated satisfactorily for the sudden acceleration of a flat plate as well as for the static and dynamic derivatives of the Saab 105/SK 60.Finally, a methodology has been developed to compute quickly in a semi-empirical way the buffet envelope of new aircraft geometries at the conceptual stage. The parameters that demonstrate functional sensitivity to buffet onset have been identified and their relative effect quantified. The method uses a combination of simple sweep theory and fractional change theory as well as the buffet onset of a seed aircraft or a provided generic buffet onset to estimate the buffet envelope of any target geometry. The method proves to be flexible and robust enough to predict within mainly 5% (and in any case 9%) the buffet onset for a wide variety of aircrafts, from regional turboprop to long-haul wide body or high-speed business jets.This work was done within the 6^th European framework project SimSAC (Simulating Stability And Control) whose task is to create a multidisciplinary simulation environment named CEASIOM (Computerized Environment for Aircraft Synthesis and Integrated Optimization Methods), oriented toward stability and control and specially suited for aircraft conceptual design sizing and optimization.</p> / SimSAC

Thesis (MPhil (Information Science))--University of Stellenbosch, 2010. / ENGLISH ABSTRACT: This thesis investigates investment theory in the light of complexity theory. These insights from diverse fields contain powerful images, metaphors and ways of thinking that allows one to seek new ways of comprehending the nature of the economy and therefore the nature of investment and the related issues of uncertainty and decision making. Complexity theory views the economy as being a dynamic, continuously adaptive, nonlinear system. This is in contrast to traditional or classical economic theory that views the economy as being a simple, linear, equilibrium deterministic system. This thesis is a conceptual study exploring the implications of a complexity worldview for investment decisions by looking at the nature and characteristics of complexity and then overlaying it on the characteristics of the economy. It is argued that complexity is caused by three elements: the structure of the system, human behaviour and exogenous factors. Thereafter follows an analysis of how investment decisions are made in the light of complexity by illustrating the investment models of two very successful, yet different investors: Warren Buffet and George Soros. Buffet’s model hinges on value. He realises that emergent phenomenon driven by irrational behaviour of investors leads to intrinsic values of shares to differ widely from perceived value. When quoted or perceived values are low than it is advisable to purchase as you have a margin of safety. Over the long term the market recognises the real value of the share. He tries to ignore the vagaries of the market and to focus on fundamentals. His list of fundamentals include; the franchise value of the company, quality of management and industry dynamics. George Soros in contrast utilises emergence patterns to locate potential investments. His model is that systems are flawed, human thinking and decision making is flawed and the interaction of the two lead to perturbations and oscillations. He focuses in trying to understand the flaw in systems and in human behaviour and to find some kind of pattern that he could utilise to make a profit. It is shown that both investment models can be understood from a complexity perspective and that these two investors built aspects from complexity into their decision models. / AFRIKAANSE OPSOMMING: Die tesis ondersoek investeringsteorie in die lig van kompleksiteitsteorie. Met die hulp van metafore en insigte vanuit kompleksiteitsdenke word gesoek na nuwe maniere om die aard van die mark en investering verwante aspekte van onsekerheid en besluitneming te verstaan. Die kompleksiteitsperspektief sien die ekonomie as’n dinamiese en aanpassende nie-lineêre sisteem. Dit word gedoen deur die implikasies wat kompleksiteit vir investeringsbesluite inhou konseptueel te ondersoek. Die aard en eienskappe van komplekse sisteme word verduidelik en dan op die ekonomie toegepas. Daar word geargumenteer dat kompleksiteit deur drie elemente veroorsaak word: die struktuur van die sisteem, menslike gedrag en eksogene faktore. Daarna word die praktyk van investeringsbesluite geanaliseer in terme van kompleksiteit duer investeringsmodelle van twee suksesvolle, maar uiteenlopende, investeerders te ondersoek, naamlik Warren Buffet en George Soros. Buffet se model draai rondom waarde. Hy sien die irrasionele gedrag van investeerders as ‘n ontvouende fenomeen wat lei tot ‘n gaping tussen intrinsieke en verwagte waarde. Sy investering word gebaseer op die aanname dat oor die langer termyn die mark die intrinsieke waarde herken. Hy ignoreer dus korttermyn skommelinge in die verwagte waarde en fokus op die fundamentele, waaronder die maanwaarde van die besigheid, die kwaliteit van die bestuur, en industrie-dinamika tel. Soros se model daarenteen gebruik ontvouende patrone en potensiële investeringsgeleenthede te ontbloot. Sy model is dat sisteme inherente teenstrydighede het as ook menslike gedrag en besluitneming. Dit lei tot ossilasies en versteurings. Sy fokus is gerig daarop om hierdie versteurings in die sisteem tot voordeel aan te wend. Daar word getoon hoedat beide investeringsmodelle vanuit ‘n kompleksiteitsperspektief verstaan kan word en dat die twee investeerders sulke aspekte in hulle investeringsbesluite inbou.

In the overall academic study of the saxophone and its history there is a considerable lack of integration in how the technological advances of the saxophone enabled the eminent virtuosi of the repertory to accomplish the challenges of saxophone technique and style. This dissertation explores the technological development of the saxophone from when the instrument was first invented in the 1850s to the 1950s. Concurrent with this investigation, the trajectory of the major repertory of the saxophone is also plotted with the technological developments of each era. This dissertation aims to synthesise and study these two aspects contemporaneously to achieve viable theories to explain the effect that saxophone manufacturers of their particular eras had on the expansion of the classical saxophone repertory. As saxophone manufacturers expanded and diversified their approach in instrument construction, the players started to gain more facility with aspects like altissimo and intonation to aid them to play the repertoire proficiently. As a result, standards in the course of the first century of the saxophone’s existence gradually become higher. This dissertation is grounded in an assortment of secondary historical sources and the concepts that surround them. This work aims to aid saxophone players to not only understand the development of their instrument and repertory, but also the concepts and utilisation of vintage saxophones of previous eras. / Dissertation (MMus)--University of Pretoria, 2014. / lk2014 / Music / MMus / Unrestricted

Dans cette étude nous considérons l'interaction entre une onde de choc et une couche limite turbulente sur un écoulement transsonique sur une bosse d'un point de vue expérimentale et théorique.Des mesures expérimentales ont permis de montrer que l'interaction est caractérisée par la coexistence de deux fréquences caractéristiques distinctes, mais l'origine des oscillations est controversée. Des simulations numériques permettent une description de l'écoulement moyen, mais ne sont pas capables de reproduire le comportement instable de l'interaction. Nous proposons d'abord une étude de stabilité globale: une décomposition en valeurs propres de l'opérateur de Navier-Stokes linéarisé indique que l'interaction est un phénomène stable, et la dynamique de l'écoulement ne peut pas être décrite par un mode global instable.Nous considérons ensuite une approche linéarisée, où la réceptivité de l'écoulement à un forçage externe est analysée à travers une décomposition en valeurs singulières du Résolvant global. Cette nouvelle approche est proposée afin d'expliquer le processus de sélection de fréquence dans cet écoulement, et montre que l'interaction filtre et amplifie le bruit résiduel existant.La même approche est enfin appliquée sur un cas d'écoulement transsonique autour d'un profil d'aile, qui peut présenter des oscillations périodiques de l'onde de choc. La décomposition en valeurs propres de opérateur de Navier-Stokes linéarisé est capable de décrire la dynamique du choc, tandis que la décomposition en valeurs singulières du Résolvant global peut indiquer la présence des instabilité convectives. / A transonic interaction between a shock wave and a turbulent boundary layer is experimentally and theoretically investigated. The configuration is a channel flow over a bump, where a shock wave causes the separation of the boundary layer and a recirculating bubble is observed downstream of the shock foot.The mean flow is experimentally investigated by means of PIV, then different techniques allows to identify the main unsteadiness of this shock-wave/boundary-layer interaction. As recognised in similar configurations, the flow presents two distinguished characteristic frequencies, whose origins are still unknown.Numerical simulations are performed solving RANS equations. Results are in good agreement with the experimental mean flow, but the approach fails to predict the unsteady. The solution of RANS equations is then considered as a base flow, and a global stability analysis is performed. Eigenvalue decomposition of the Navier-Stokes operator indicates that the interaction is stable, and the dynamics cannot be described by unstable global modes.A linearised approach based on a singular-value decomposition of the Resolvent is then proposed: the noise-amplifier behaviour of the flow is highlighted by the linearised approach. Medium-frequency perturbations are shown to be the most amplified in the mixing layer, whilst the shock wave behaves as a low-pass filter.The same approach is then applied to a transonic flow over a profile, where the flow can present high-amplitude shock oscillations. The stability analysis can describe both the buffet phenomenon when an unstable mode is present, and the convective instabilities responsible of medium-frequency unsteadiness.

This thesis presents the work done to implement new computational tools and methods dedicated to aircraft conceptual design sizing and optimization. These tools have been exercised on different aircraft concepts in order to validate them and assess their relevance and applicability to practical cases. First, a geometry construction protocol has been developed. It is indeed essential to have a geometry description that supports the derivation of all discretizations and idealizations used by the different analysis modules (aerodynamics, weights and balance, stability and control, etc.) for which an aircraft concept is evaluated. The geometry should also be intuitive to the user, general enough to describe a wide array of morphologies and suitable for optimization. All these conditions are fulfilled by an appropriate parameterization of the geometry. In addition, a tool named CADac (Computer Aided Design aircraft) has been created in order to produce automatically a closed and consistent CAD solid model of the designs under study. The produced CAD model is easily meshable and therefore high-fidelity Computational Fluid Dynamics (CFD) computations can be performed effortlessly without need for tedious and time-consuming post-CAD geometry repair.Second, an unsteady vortex-lattice method based on TORNADO has been implemented in order to enlarge to scope of flight conditions that can be analyzed. It has been validated satisfactorily for the sudden acceleration of a flat plate as well as for the static and dynamic derivatives of the Saab 105/SK 60.Finally, a methodology has been developed to compute quickly in a semi-empirical way the buffet envelope of new aircraft geometries at the conceptual stage. The parameters that demonstrate functional sensitivity to buffet onset have been identified and their relative effect quantified. The method uses a combination of simple sweep theory and fractional change theory as well as the buffet onset of a seed aircraft or a provided generic buffet onset to estimate the buffet envelope of any target geometry. The method proves to be flexible and robust enough to predict within mainly 5% (and in any case 9%) the buffet onset for a wide variety of aircrafts, from regional turboprop to long-haul wide body or high-speed business jets.This work was done within the 6th European framework project SimSAC (Simulating Stability And Control) whose task is to create a multidisciplinary simulation environment named CEASIOM (Computerized Environment for Aircraft Synthesis and Integrated Optimization Methods), oriented toward stability and control and specially suited for aircraft conceptual design sizing and optimization. / QC 20101104 / SimSAC

We tackle the problem of identifying the structural dynamics of the twin tails of the F-15 fighter plane. The objective is to first investigate and identify the different possible attractors that coexist for the same operating parameters. Second is to develop a model that simulates the experimentally determined dynamics. Third is to suppress the high-amplitude vibrations of the tails due to either principal parametric or external excitations. To understand the dynamical characteristics of the twin-tails, the model is excited parametrically. For the same excitation amplitude and frequency, five different responses are observed depending on the initial conditions. The coexisting five responses are the result of the nonlinearities. After the experimental identification of the system, we develop a model to capture the dynamics realized in the experiment. We devise a nonlinear control law based on cubic velocity feedback to suppress the response of the model to a principal parametric excitation. The performance of the control law is studied by comparing the open- and closed-loop responses of the system. Furthermore, we conduct experiments to verify the theoretical analysis. The theoretical and experimental findings indicate that the control law not only leads to effective vibration suppression, but also to effective bifurcation control. We investigate the design of a neural-network-based adaptive control system for active vibration suppression of the model when subjected to a parametric excitation. First, an emulator neural network was trained to represent the structure and thus used to predict the future responses of the model. Second, a neurocontroller is developed to determine the necessary control action. The computer-simulation studies show great promise for artificial neural networks to control the model vibrations caused by parametric excitations. We investigate the use of four different control strategies to suppress high-amplitude responses of the F-15 fighter to a primary resonance excitation. The control strategies are linear velocity feedback, nonlinear velocity feedback, positive position feedback, and saturation-based control. For each case, we conduct bifurcation analyses for the open- and closed-loop responses of the system and investigate theoretically the performance of the different control strategies. We also calculate the instantaneous power requirements of each control law. The experimental results agree with the theoretical findings. / Ph. D.