Real-time simulation of multibody systems with applications for working mobile vehicles

This dissertation describes an approach for developing a real-time simulation for working mobile vehicles based on multibody modeling. The use of multibody modeling allows comprehensive description of the constrained motion of the mechanical systems involved and permits real-time solving of the equations of motion. By carefully selecting the multibody formulation method to be used, it is possible to increase the accuracy of the multibody model while at the same time solving equations of motion in real-time. In this study, a multibody procedure based on semi-recursive and augmented Lagrangian methods for real-time dynamic simulation application is studied in detail. In the semirecursive approach, a velocity transformation matrix is introduced to describe the dependent coordinates into relative (joint) coordinates, which reduces the size of the generalized coordinates. The augmented Lagrangian method is based on usage of global coordinates and, in that method, constraints are accounted using an iterative process. A multibody system can be modelled as either rigid or flexible bodies. When using flexible bodies, the system can be described using a floating frame of reference formulation. In this method, the deformation mode needed can be obtained from the finite element model. As the finite element model typically involves large number of degrees of freedom, reduced number of deformation modes can be obtained by employing model order reduction method such as Guyan reduction, Craig-Bampton method and Krylov subspace as shown in this study The constrained motion of the working mobile vehicles is actuated by the force from the hydraulic actuator. In this study, the hydraulic system is modeled using lumped fluid theory, in which the hydraulic circuit is divided into volumes. In this approach, the pressure wave propagation in the hoses and pipes is neglected. The contact modeling is divided into two stages: contact detection and contact response. Contact detection determines when and where the contact occurs, and contact response provides the force acting at the collision point. The friction between tire and ground is modelled using the LuGre friction model, which describes the frictional force between two surfaces. Typically, the equations of motion are solved in the full matrices format, where the sparsity of the matrices is not considered. Increasing the number of bodies and constraint equations leads to the system matrices becoming large and sparse in structure. To increase the computational efficiency, a technique for solution of sparse matrices is proposed in this dissertation and its implementation demonstrated. To assess the computing efficiency, augmented Lagrangian and semi-recursive methods are implemented employing a sparse matrix technique. From the numerical example, the results show that the proposed approach is applicable and produced appropriate results within the real-time period.

A persistência da indexação no Brasil pós-Real

The paper analyzes the shortcomings of the Real Plan combining political science and economics, considering evidences on difficulties in implementing a complete plan of deindexation, namely: the distributional conflict, the corporatist relations between the State and society and the bureaucratic isolation of a highly specialized technocracy. The announcement of the plan triggered defensive reactions, fueling distributive tensions during the URV period, forcing the economic team to take measures that contradicted the overall guidelines followed. The persistence of indexation mechanisms indicate the resulting obstacles in seeking a reform of the State through a stabilization plan, even though the latter has the former as a precondition.

O que há de real e de irreal com o realismo: Searle versus Rorty

O texto fala a respeito do debate entre Searle e Rorty sobre "irracionalismo" de Rorty. Ele tenta mostrar que a posição de Rorty está fora do campo "realismo versus anti-realismo" e o "irracionalismo" não é um bom adjetivo. Searle estaria sobre uma linha incorreta em sua abordagem do tema da verdade em Rorty.

O direito real de Kant

No direito real, Kant investiga a propriedade privada de uma substância (o solo e os objetos localizados nele). No estado de natureza, somente ocorre a posse física ou empírica de um objeto externo, a partir do postulado jurídico da razão prática como uma lei permissiva, pois, do contrário, as coisas utilizáveis seriam em-si ou res nullius, mas a posse jurídica ou inteligível depende da posse comum originária do solo (que não se confunde com o comunismo primitivo), para evitar que a propriedade seja uma relação entre pessoas e coisas, como acontece na teoria do trabalho, porque todo direito exige um dever correspondente. Todavia, coisas não podem ter deveres com relação a pessoas, condição seguida da vontade unilateral do primeiro ocupante de querer o objeto e do advento de uma vontade unificada a priori do provo, que só se torna efetiva no estado civil, a única capaz de gerar uma obrigação recíproca entre todos; por isso, a posse inteligível somente é possível no estado civil, embora a posse empírica do estado de natureza tenha a presunção de tornar-se jurídica, quando ocorrer a entrada no estado jurídico e vale por comparação na espera e preparação daquele estado.

Mundo Real e Mundo Ideal em Rousseau: da Necessidade da Ficção para Pensar o Político

RESUMO:A hipótese desenvolvida nos leva a confrontar três textos do corpusrousseauísta: o Segundo Discurso, Júlia ou A Nova Heloísa e o extrato do Primeiro Diálogo, em que há a ficção do mundo ideal, textos que, apesar do seu estatuto genérico diferente, estão em coerência e convergência teórica. Desejamos evidenciar um aspecto da unidade problemática do pensamento de Rousseau concernente à abordagem crítica da sociedade de seus contemporâneos e sua concepção do papel das Letras e dos Espetáculos. A preocupação do filósofo é de refundar a natureza humana, a fim de lançar as bases de uma nova organização social. Nessa empreitada, a ficção desempenha um papel crucial, o prefácio do Segundo Discurso o comprova: para bem conhecer o homem atual, deve-se supor o que ele não é mais. O homem do estado de natureza, ser de ficção, cujas paixões são retas e naturais, é o modelo teórico que reativa a sociedade dos seres ideais de Júlia. Dessa forma, a ficção é chamada a desempenhar um papel referencial fundamental para o pensamento social e político de Rousseau, aparecendo como um poderoso meio de ação sobre o público. O romance pode reeducar os povos corrompidos, pois, assim como o teatro, como denuncia a Carta a d’Alembert, possui os meios para perverter uma sociedade tida como virtuosa.

Real-time adaptive control of ultra-fast laser scribing process with spectrometer online monitoring

There exist several researches and applications about laser welding monitoring and parameter control but not a single one have been created for controlling of laser scribing processes. Laser scribing is considered to be very fast and accurate process and thus it would be necessary to develop accurate turning and monitoring system for such a process. This research focuses on finding out whether it would be possible to develop real-time adaptive control for ultra-fast laser scribing processes utilizing spectrometer online monitoring. The thesis accurately presents how control code for laser parameter tuning is developed using National Instrument's LabVIEW and how spectrometer is being utilized in online monitoring. Results are based on behavior of the control code and accuracy of the spectrometer monitoring when scribing different steel materials. Finally control code success is being evaluated and possible development ideas for future are presented.

Life-related negative customer emotions in real estate agent encounters

The goal of this study was to explore how do customers’ life-related negative emotions affect real estate business. This was divided into two research questions: 1. What life-related negative emotions can be recognised in real estate customer encounters? 2. How do the recognised emotions affect customer encounters and the realtor’s work? 3. How can the realtor take the emotions into account in customer service? The theoretical background consists of two main lines of study: emotions and customer encounters. A wide literary review on emotions research was conducted from a cognitive psychology point of view, focusing on negative emotions. Emotions research was then combined into the field of customer encounters. Qualitative study was chosen as the methodological basis of the study. Empirical material of this study was collected through in-depth interviews with 13 successful Finnish real estate agents. Narrative research was used as a method for the study. Four life-related emotion categories were recognized in real estate customer encounters: sadness, anger, anxiety and shame. These emotions rose from issues varying from death of a close one to divorce and from major changes in life stages to deep emotional attachment to an old home. The study also found that these incidental negative emotions do affect customer encounters and realtors’ work. The emotions affected the decision making of customers and sometimes overshadowed reason. Some emotions made the customer passive and slow to make any decisions, while others made their decision making fast and hasty. Even though the incidental emotions might not have had anything to do with the real estate deal, they could affect the outcome of the customer encounter and the whole real estate deal. Interestingly enough, the study found that not all successful real estate agents knowingly serve customers in an emotional level. The study does, however, suggest that in fact it may be an ethical decision of the customer server to take into account the emotional state of the customer. Attending to the emotional side of customers does not only increase pleasantness of the customer encounter, but may improve and balance customer decision making and prevent hasty decisions possibly leading to improved customer satisfaction. This study also gave practical managerial implications to customer service providers on how negative incidental emotions can be attended to in a customer encounter. This study could be useful not only to real estate agents, but also in other types of customer service, especially with vulnerable populations or other types of home-related business.

Real-time monitoring of laser scribing process utilizing high-speed camera

Currently, laser scribing is growing material processing method in the industry. Benefits of laser scribing technology are studied for example for improving an efficiency of solar cells. Due high-quality requirement of the fast scribing process, it is important to monitor the process in real time for detecting possible defects during the process. However, there is a lack of studies of laser scribing real time monitoring. Commonly used monitoring methods developed for other laser processes such a laser welding, are sufficient slow and existed applications cannot be implemented in fast laser scribing monitoring. The aim of this thesis is to find a method for laser scribing monitoring with a high-speed camera and evaluate reliability and performance of the developed monitoring system with experiments. The laser used in experiments is an IPG ytterbium pulsed fiber laser with 20 W maximum average power and Scan head optics used in the laser is Scanlab’s Hurryscan 14 II with an f100 tele-centric lens. The camera was connected to laser scanner using camera adapter to follow the laser process. A powerful fully programmable industrial computer was chosen for executing image processing and analysis. Algorithms for defect analysis, which are based on particle analysis, were developed using LabVIEW system design software. The performance of the algorithms was analyzed by analyzing a non-moving image from the scribing line with resolution 960x20 pixel. As a result, the maximum analysis speed was 560 frames per second. Reliability of the algorithm was evaluated by imaging scribing path with a variable number of defects 2000 mm/s when the laser was turned off and image analysis speed was 430 frames per second. The experiment was successful and as a result, the algorithms detected all defects from the scribing path. The final monitoring experiment was performed during a laser process. However, it was challenging to get active laser illumination work with the laser scanner due physical dimensions of the laser lens and the scanner. For reliable error detection, the illumination system is needed to be replaced.

Les Corte-Real et leurs voyages au Nouveau-Monde d'après des documents nouveaux ou peu connus tirés des archives de Lisbonne et de Modène... ; Récit de la troisième expédition de Gaspar Corte-Real ; Gaspar Corte-Real, la date exacte de sa dernière expédition au Nouveau-Monde, d'après deux documents inédits récemment tirés des archives de La Torre do Tombo à Lisbone, dont un écrit et signé par Gaspar Corte-Real, l'autre par son frère Miguel / [publ.] par Henri Harrisse

Collection : Recueil de voyages et de documents pour servir à l'histoire de la géographie depuis le XIIIe jusqu'à la fin du XVIe siècle ; 3

Una revolución por minuto, tiempo real y futuro perfecto. Una entrevista con Ximena Diaz

Programas, proyectos y red de portales

Caso Lácteos Campo Real 2012

Desarrollo empresarial y creación de empresa