• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 34
  • 24
  • 14
  • 6
  • 4
  • 4
  • 4
  • 3
  • 3
  • 1
  • 1
  • Tagged with
  • 103
  • 18
  • 15
  • 15
  • 14
  • 14
  • 13
  • 12
  • 12
  • 11
  • 11
  • 10
  • 10
  • 10
  • 9
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
51

Design rýpadla / Design of excavator

Brza, Lukáš January 2009 (has links)
The design of the excavator follows requirements of machines for demolition work. The excavator is equipped with an innovative type of under carriage, which not only increases mobility over the demolition sites but also the visibility from the driver’s cabin. The components of the excavator, that improve the demolition work, are special types of tracks, suspensions and articulated steering. Tracks can change their shape to increase the stability and also to adapt to the diff erent types of ground. The suspensions with tracks are able to adapt to the terrain thereby they lighten the asperity. Suspension can also tilt or even raise the excavator and thereby increase the angle of visibility from the cabin. This function is necessary mainly when taking down higher constructions. Articulated steering is a new function that has never been used for excavators. This steering was chosen due to fl exible movement over demolition sites. The main aim of the project is to create a new design of the excavator, but more importantly to distinguish the excavator from the excavators already on the market, with regards to its esthetics and under carriage innovation.
52

3D-Reconstruction of the Common Murre / 3D-Rekonstruering av Sillgrissla

Hägerlind, Johannes January 2023 (has links)
Automatic 3D reconstruction of birds can aid researchers in studying their behavior. Recently there has been an attempt to reconstruct a variety of birds from single-view images. However, the common murre's appearance is different from the birds that have been studied. Moreover, recent studies have focused on side views. This thesis studies the 3D reconstruction of the common murre from single-view top-view images. A template mesh is first optimized to fit a 3D scan. Then the result is used to optimize a species-specific mean from side-view images annotated with keypoints and silhouettes. The resulting mean mesh is used to initialize the optimization for top-down images. Using a mask loss, a pose prior loss, and a bone length loss that uses a mean vector from the side-view images improves the 3D reconstruction as rated by humans. Furthermore, the intersection over union (IoU) and percentage of correct keypoint (PCK), although used by other authors, are insufficient in a single-view top-view setting.
53

AutoTruck : Automated docking with internal sensors / Självparkerande lastbil

Andersson, Oscar, Molin, Lucas January 2018 (has links)
The purpose of this bachelor thesis was to discover howan articulated vehicle can park itself using a pre-definedparking path with a combination of ultrasonic sensors aswell as a rotary angle sensor.The project was divided into two parts: constructing asmall scale demonstrator and the software controlling thedemonstrator. The demonstrator was constructed from offthe-shelf components and custom parts. The truck was designedbased on a rear wheel driven truck with Ackermannsteering. The localization of a parking spot and measuringother distances was done with ultrasonic sensors and thehitch angle was measured by a rotary angle sensor.The performance of the demonstrator was evaluated bymeasuring the trailers angle difference from the center lineof the parking spot.The performance was deemed to be reasonably goodwith successful parkings in 8 out of 10 attempts. / Kandidatarbetet syftar till att undersöka hur ett ledatfordon kan parkera sig självt efter en förbestämd parkeringsruttmed en kombination av flera ultraljudssensorersamt en vinkelgivare.Projektet består av två delar; konstruktion av ett miniatyrfordonsamt mjukvaran som styr fordonet. Fordonettillverkades från butiksköpta komponenter och skräddarsyddadelar. Lastbilens design var baserad p°a en bakhjulsdrivenAckermannstyrd lastbil. Identifieringen av en parkeringsplatssamt avståndsmätning hanterades av ultraljudssensoreroch hitch vinkeln mättes av en vinkelgivare.Miniatyrfordonets prestanda utvärderades genom attmäta släpets vinkelskillnad från centerlinjen av parkeringsplatsen.Prestandan ansågs att vara tillräckligt god med lyckadeparkeringar i 8 av 10 tester.
54

Robotik im Holzbau: Untersuchung grundlegender Fragen der Vorfertigung

Kuhl, Janina Bea Doreen 01 December 2023 (has links)
Die vorliegende Bachelorarbeit untersucht die Thematik der Vorfertigung im Holzbau und zielt darauf ab, einen umfassenden Einblick zu der Entwicklung, den Praktiken, den Herausforderungen und Potentialen zu geben. Angesichts des steigenden Fachkräftemangels sowie der wachsenden Nachfrage nach bezahlbarem, qualitativ hochwertigem Wohnraum stellt die Produktion im Werk eine entscheidende Komponente für die zukünftige Entwicklung der Bauindustrie dar. Dabei wird die Integration von automatisierten Lösungen und Robotik thematisiert. Das Ziel dieser Arbeit besteht darin, die Möglichkeiten und Herausforderungen der Integration solcher Systeme zu untersuchen und Handlungsempfehlungen für die Umsetzung in Werkhallen abzuleiten. Um einen ausgewogenen Überblick zu gewährleisten, basiert die Untersuchung auf einer Analyse der traditionellen Vorfertigung und deren Limitation. Dabei werden zusätzlich automatisierte Technologien berücksichtigt. Ein Hauptaugenmerk liegt darauf, wie Robotik in diesem Kontext den Produktionsprozess optimieren kann. Im Zuge dieser Analyse werden Vorteile wie Effizienzsteigerung, Produktivität, Präzision und Ressourcenmanagement sowie potenzielle Herausforderungen in Bezug auf eine hohe Anfangsinvestition, Schulungsbedarf und Flexibilitätseinschränkungen herausgestellt. Die wichtigsten Erkenntnisse, aus der Quellenarbeit und den Experteninterviews, zeigen die wachsende Bedeutung der Integration von Robotik in der Vorfertigung im Holzbau und verdeutlichen die Notwendigkeit weiterer Forschung und Entwicklung in diesem Bereich. Die vorliegende Arbeit legt einen Grundstein für das Verständnis der Vorfertigungsprozesse, die Integrationsmöglichkeit verschiedener Technologien und fördert das Verständnis der Potenziale und Herausforderungen, die mit der Nutzung dieser Technologien einher gehen. ...:1 Einleitung 2 Theoretische Grundlagen der Vorfertigung 2.1 Vorfertigung 2.1.1 Begriffsdefinitionen 2.1.2 Intention und Voraussetzungen der Vorfertigung 2.1.3 Vor- und Nachteile des Bauens mit vorgefertigten Elementen 2.1.4 Kritische Gegenüberstellung zur konventionellen Produktion 2.2 Automatisierung und Digitalisierung im Kontext 2.2.1 Begriffsabgrenzung 2.2.2 Notwendigkeit des Ausbaus der Vorproduktion im Holzbau 2.2.3 Analyse der aktuellen Vorproduktionsprozesse in der Werkhalle 3 Effizienzsteigerung durch Prozessanalysen und Automatisierung 3.1 Identifizierung von Engpässen und Schwachstellen 3.2 Einsatz moderner Technologien und Maschinen 3.2.1 Fertigungsform 3.2.2 Materialzuführung 3.2.3 Varianten des Aufbaus 3.3 Automatisierung – Chancen und Herausforderungen 4 Der robotergestützte Ansatz in der Werksfertigung des Holzbaus 4.1 Einführung in den robotergestützten Ansatz 4.1.1 Grundprinzipien 4.1.2 Aufbau 4.1.3 Konvertierung der Daten 4.1.4 Varianten des Aufbaus 4.1.5 Auswahl des passenden Roboters 4.2 Vor- und Nachteile des robotergestützten Ansatzes 4.3 Anwendungsbeispiel 5 Ergebnisse der Untersuchung 5.1 Gegenüberstellung der Fertigungsmethoden 5.2 Handlungsempfehlung für die Integration in Werkshallen 6 Zusammenfassung und Ausblick Ehrenwörtliche Erklärung Literaturverzeichnis Online - Quellen Abbildungsverzeichnis Anhang / This bachelor thesis explores the topic of prefabrication in timber construction and aims to provide a comprehensive insight into the development, practices, challenges and potentials. In view of the increasing shortage of skilled workers and the growing demand for affordable, high-quality housing, factory production is a crucial component for the future development of the construction industry. The integration of automated solutions and robotics will be addressed. The aim of this work is to investigate the possibilities and challenges of integrating such systems and to derive recommendations for action for implementation in factory buildings. To ensure a balanced overview, the study is based on an analysis of traditional prefabrication and its limitations. Automated technologies are also taken into account. A main focus is on how robotics can optimise the production process in this context. In the course of this analysis, benefits such as increased efficiency, productivity, precision and resource management are highlighted, as well as potential challenges in terms of high initial investment, training needs and flexibility limitations.The main findings from the source work and the expert interviews show the growing importance of the integration of robotics in prefabrication in timber construction and highlight the need for further research and development in this area. This thesis lays a foundation for understanding the prefabrication processes, the integration possibilities of different technologies and promotes the understanding of the potentials and challenges associated with the use of these technologies. The work emphasises the importance of further research and implementation of robotics in prefabrication to ensure the competitiveness and sustainability of the timber construction industry and to drive innovative advances.:1 Einleitung 2 Theoretische Grundlagen der Vorfertigung 2.1 Vorfertigung 2.1.1 Begriffsdefinitionen 2.1.2 Intention und Voraussetzungen der Vorfertigung 2.1.3 Vor- und Nachteile des Bauens mit vorgefertigten Elementen 2.1.4 Kritische Gegenüberstellung zur konventionellen Produktion 2.2 Automatisierung und Digitalisierung im Kontext 2.2.1 Begriffsabgrenzung 2.2.2 Notwendigkeit des Ausbaus der Vorproduktion im Holzbau 2.2.3 Analyse der aktuellen Vorproduktionsprozesse in der Werkhalle 3 Effizienzsteigerung durch Prozessanalysen und Automatisierung 3.1 Identifizierung von Engpässen und Schwachstellen 3.2 Einsatz moderner Technologien und Maschinen 3.2.1 Fertigungsform 3.2.2 Materialzuführung 3.2.3 Varianten des Aufbaus 3.3 Automatisierung – Chancen und Herausforderungen 4 Der robotergestützte Ansatz in der Werksfertigung des Holzbaus 4.1 Einführung in den robotergestützten Ansatz 4.1.1 Grundprinzipien 4.1.2 Aufbau 4.1.3 Konvertierung der Daten 4.1.4 Varianten des Aufbaus 4.1.5 Auswahl des passenden Roboters 4.2 Vor- und Nachteile des robotergestützten Ansatzes 4.3 Anwendungsbeispiel 5 Ergebnisse der Untersuchung 5.1 Gegenüberstellung der Fertigungsmethoden 5.2 Handlungsempfehlung für die Integration in Werkshallen 6 Zusammenfassung und Ausblick Ehrenwörtliche Erklärung Literaturverzeichnis Online - Quellen Abbildungsverzeichnis Anhang
55

Bullerreduktion av hytt på Volvodumprar : Undersökning, mätning och analys / Noise reduction in the cabin of a Volvo articulated hauler : Study, measurement and analysis

Muftic, Armin, Chamoun, Simon January 2010 (has links)
<p>Too high levels of noise lead to various health problems and cost society billions of SEK peryear. In this thesis we have examined a model of the A40E articulated hauler at VolvoConstruction Equipment in Braås. We have tried to reduce cabin noise in an articulated hauler,while also providing a way on how to proceed with a machine when the cabin does not measureup to the sound requirement. The best way to find leaks were with a reference source of model4205 and its speaker HP 1001 from Brüel & Kjaer in the cab and then walk around and listen towhere the reference source was more prominent. In this way, we found that the edges and theplugs were sensitive areas. We managed to reduce cabin noise 2.77 dB(A) at 1900 rpm, byisolating certain areas with glass wool. We have also looked at how certain areas individually canreduce cabin noise. We concluded that the isolation of the following areas gave the bestresponse: Cabin ceiling, cabin floor, cabin door, window edges around the dashboard, torpedowall.</p>
56

Low Loss Articulated Hauler Axle : A Conceptual Study / Lågförlustaxel till ramstyrd dumper : En konceptstudie

Andersson, Patrik, Wallin, Morgan January 2017 (has links)
Volvo Construction Equipment is highly regarded for robust products, but with an increasing competition in their market, development of the product portfolio is more important than ever. One step being carried out is to reduce losses in powertrains and increase the fuel efficiency for solutions such as articulated haulers and wheel loaders. This would eventually lower the fuel costs and emissions for the end customer. With this development, Volvo CE could strengthen their position in the market while also contributing to reducing the construction industry's environmental impact. By investigating the front bogie axle of the recently introduced hauler, Volvo A60H, important information about possible reductions and the distribution of the current losses were found. The investigation focused on a front bogie axle, but some of the results are applicable for other applications such as wheel loaders as well, since a lot of the technology in the axles are similar. A conceptual study was performed where completely new ideas were generated, such as implementing a dry sump system in the axle, as well as ideas for improving the subcomponents currently found in the axle. Two cases were presented for the evaluation of concepts, one with a fully loaded dump body and low speeds, and one with an unloaded dump body and a wider speed interval. The concepts were later evaluated using calculation tools such as MATLAB and a Simulink-model was created for the losses in the axle. When combining concepts that reduces load dependent losses, a potential reduction of 64% of the axle's total losses was achieved for the case with a full dump body. The largest improvement found for the load independent losses was 8% with an unloaded hauler and the highest speed investigated, 50 km/h. A dry sump system improves the axle's efficiency with 45% in optimal working conditions, but was found to lower the efficiency at other conditions. Room for improvement of axle losses currently exists both for load dependent and load independent losses. The evaluation performed pointed towards the load dependent losses being the largest influence on the total losses, even with an unloaded dump body and high speeds. This is an interesting observation since a lot of work at Volvo CE has revolved around reducing the load independent losses since these are easier to affect with different lubrication levels and rotational speeds. A test methodology for load dependent losses should be implemented in order to validate the results of this thesis work, and also to aid further development at Volvo CE.
57

Human pose estimation and action recognition by multi-robot systems / Estimation de pose humaine et reconnaissance d’action par un système multi-robots

Dogan, Emre 07 July 2017 (has links)
L'estimation de la pose humaine et la reconnaissance des activités humaines sont des étapes importantes dans de nombreuses applications comme la robotique, la surveillance et la sécurité, etc. Actuellement abordées dans le domaine, ces tâches ne sont toujours pas résolues dans des environnements non-coopératifs particulièrement. Ces tâches admettent de divers défis comme l'occlusion, les variations des vêtements, etc. Les méthodes qui exploitent des images de profondeur ont l’avantage concernant les défis liés à l'arrière-plan et à l'apparence, pourtant, l’application est limitée pour des raisons matérielles. Dans un premier temps, nous nous sommes concentrés sur la reconnaissance des actions complexes depuis des vidéos. Pour ceci, nous avons introduit une représentation spatio-temporelle indépendante du point de vue. Plus précisément, nous avons capturé le mouvement de la personne en utilisant un capteur de profondeur et l'avons encodé en 3D pour le représenter. Un descripteur 3D a ensuite été utilisé pour la classification des séquences avec la méthodologie bag-of-words. Pour la deuxième partie, notre objectif était l'estimation de pose articulée, qui est souvent une étape intermédiaire pour la reconnaissance de l'activité. Notre motivation était d'incorporer des informations à partir de capteurs multiples et de les fusionner pour surmonter le problème de l'auto-occlusion. Ainsi, nous avons proposé un modèle de flexible mixtures-of-parts multi-vues inspiré par la méthodologie classique de structure pictural. Nous avons démontré que les contraintes géométriques et les paramètres de cohérence d'apparence sont efficaces pour renforcer la cohérence entre les points de vue, aussi que les paramètres classiques. Finalement, nous avons évalué ces nouvelles méthodes sur des datasets publics, qui vérifie que l'utilisation de représentations indépendantes de la vue et l'intégration d'informations à partir de points de vue multiples améliore la performance pour les tâches ciblées dans le cadre de cette manuscrit. / Estimating human pose and recognizing human activities are important steps in many applications, such as human computer interfaces (HCI), health care, smart conferencing, robotics, security surveillance etc. Despite the ongoing effort in the domain, these tasks remained unsolved in unconstrained and non cooperative environments in particular. Pose estimation and activity recognition face many challenges under these conditions such as occlusion or self occlusion, variations in clothing, background clutter, deformable nature of human body and diversity of human behaviors during activities. Using depth imagery has been a popular solution to address appearance and background related challenges, but it has restricted application area due to its hardware limitations and fails to handle remaining problems. Specifically, we considered action recognition scenarios where the position of the recording device is not fixed, and consequently require a method which is not affected by the viewpoint. As a second prob- lem, we tackled the human pose estimation task in particular settings where multiple visual sensors are available and allowed to collaborate. In this thesis, we addressed these two related problems separately. In the first part, we focused on indoor action recognition from videos and we consider complex ac- tivities. To this end, we explored several methodologies and eventually introduced a 3D spatio-temporal representation for a video sequence that is viewpoint independent. More specifically, we captured the movement of the person over time using depth sensor and we encoded it in 3D to represent the performed action with a single structure. A 3D feature descriptor was employed afterwards to build a codebook and classify the actions with the bag-of-words approach. As for the second part, we concentrated on articulated pose estimation, which is often an intermediate step for activity recognition. Our motivation was to incorporate information from multiple sources and views and fuse them early in the pipeline to overcome the problem of self-occlusion, and eventually obtain robust estimations. To achieve this, we proposed a multi-view flexible mixture of parts model inspired by the classical pictorial structures methodology. In addition to the single-view appearance of the human body and its kinematic priors, we demonstrated that geometrical constraints and appearance- consistency parameters are effective for boosting the coherence between the viewpoints in a multi-view setting. Both methods that we proposed was evaluated on public benchmarks and showed that the use of view-independent representations and integrating information from multiple viewpoints improves the performance of action recognition and pose estimation tasks, respectively.
58

Análise do desempenho estrutural e hidráulico de um pavimento permeável com revestimento de blocos de concreto unidirecionalmente articulados. / Hydraulic and structural performance analysis of a permeable pavement with articulated concrete block surface layer.

Ono, Bruno Watanabe 13 March 2018 (has links)
O emprego de pavimentos permeáveis tem se tornado cada vez mais necessário como medida compensatória para amortecer as vazões de pico e atenuar os impactos gerados pelas chuvas torrenciais em áreas altamente urbanizadas. Dentre os materiais convencionalmente adotados como revestimento permeável no contexto nacional destacam-se os blocos de concreto intertravados (BCI) e o asfalto poroso. No entanto, internacionalmente, existem materiais alternativos que podem apresentar permeabilidade igual ou até mesmo superior. Sob esse prisma, convém destacar o uso dos blocos de concreto articulados (BCA), recentemente adotados nos Estados Unidos e na Coréia do Sul, cuja capacidade de infiltração vem mostrando-se bastante promissora. Diferentemente dos blocos intertravados, os BCA foram projetados para trabalhar em conjunto, já que são interconectados por meio do encaixe das articulações unidirecionais de cada peça, sobrepostas umas às outras, dispensando assim o uso de material de rejunte, o que por sua vez aumenta a permeabilidade do revestimento. Contudo, embora o desempenho hidráulico aparente ser eficaz, questiona-se se o pavimento de blocos de concreto articulados (PBCA) comporta-se de forma igualmente satisfatória em termos estruturais. Nesse sentido, visando avaliar o desempenho estrutural e hidráulico de um pavimento permeável de BCA, foi construída uma pista experimental (20 x 5 m) no Campus da USP, adotando-se dois tipos de base, uma de agregado reciclado (RCD) e outra de agregado natural (brita 1). Na análise estrutural utilizaram-se como parâmetros de avaliação as deflexões máximas obtidas via FWD (Falling Weight Deflectometer), a eficiência de transferência de carga (LTE - Load Transfer Efficiency) e por fim, os módulos de resiliência retroanalisados para cada camada. Ademais, a pesquisa ainda avaliou a influência da presença de fissuras ou trincas nos blocos no desempenho estrutural do pavimento, já que acabaram tornando-se recorrentes em ambas as seções avaliadas. Já na avaliação hidráulica, monitorou-se a taxa de infiltração in situ ao longo de quase vinte meses. Complementarmente, foram realizadas ainda avaliações laboratoriais dos materiais empregados e funcionais do pavimento. A análise estrutural indicou que o sentido articulado do BCA obteve respostas estruturais nitidamente melhores que o sentido não articulado em termos de módulo de resiliência, deflexões máximas e LTE, evidenciando que de fato as articulações conferem intertravamento ao pavimento, próximo ao propiciado pela areia de rejunte no BCI. A base de RCD por apresentar uma distribuição granulométrica mais bem distribuída do que a brita 1, também obteve melhores resultados. Já a presença de trincas ou fissuras nos blocos não acarretou comprometimento no desempenho estrutural da pista experimental, devido ao baixo grau de severidade da maioria das patologias encontradas, como atestou o levantamento funcional, cuja classificação indicou um pavimento em boas condições de serventia. No que diz respeito ao desempenho hidráulico, o pavimento apresentou um desempenho adequado em termos de capacidade de infiltração. Apesar da perda progressiva estimada em 20% ao ano, as taxas de infiltração in situ mantiveram-se acima de 10-3 m/s em todos os ensaios realizados, sendo, portanto, superior à maioria dos revestimentos permeáveis tradicionalmente utilizados como os blocos intertravados e a camada porosa de atrito, conforme descritos pela literatura. / Pervious pavements have become increasingly fundamental as a compensatory measure to attenuate peak flows and to mitigate the impacts generated by torrential storm water in highly urbanized areas. Among the usual materials applied in permeable surface layers, it is possible to highlight the interlocking concrete blocks (ICB) and the porous asphalt. However, internationally, there are alternative materials that are able to present a higher permeability. In this sense, the use of articulated concrete blocks (ACB) needs to be stressed. Recently adopted in United States of America and South Korea, ACB has presented promising infiltration rates. Unlike the ICB, the ACB was designed to work as an integrated framework due to the presence of articulated joints in one of the block directions, which allows discarding the jointing sand and as result, increases water infiltration. Nevertheless, although the pavement hydraulic performance seems to be successful, there are some doubts about the structural behavior. Thereby, aiming at evaluating the hydraulic and structural performance of an unidirectionally articulated concrete block pavement, a pavement experimental section (20 x 5 meters) was constructed at the University of São Paulo Campus. Two types of different bases were applied, namely recycled concrete aggregate (RCA) and natural aggregate. The structural assessment took into account the maximum deflection measurements, the load transfer efficiency (LTE) and the backcalculated elastic moduli of each layer. In addition, this work also evaluated the structural influence caused by the presence of damaged pavers, since it became a recurring problem. Regarding the hydraulic evaluation, the surface infiltration rate was monitored over twenty months after the pavement construction. Furthermore, functional and laboratorial analyses were carried out in order to check the structure serviceability level. The structural results indicated clearly that the articulated block side had better performance than the non-articulated block side in terms of elastic moduli, maximum deflections measurements and LTE, confirming the interlocking efficiency generated by the block shape, comparable to that one provided by the jointing sand in ICB. As the recycled aggregate was characterized by a more well graded particle size distribution than the natural aggregate, the RCA base also presented better structural responses. The presence of damaged blocks did not compromise the pavement structural performance, since the degree of severity was low, as verified by the functional evaluation, which showed a pavement in good conditions. Finally, concerning the hydraulic results, the pavement presented a high infiltration capacity. Even though an infiltration loss of about 20% per year has been detected, the infiltration rate remained greater than 10-3 m/s for all tests performed, being considerably higher than those found in pavements built with both interlocking concrete blocks and with porous asphalt, as reported in the literature.
59

[en] ANALYSIS OF THE UN-REDUC - PETROBRAS MANAGEMENT SYSTEM: A ADAPTIVE PLANNING PERSPECTIVE / [pt] ANÁLISE DO SISTEMA DE GESTÃO DA UN-REDUC - PETROBRAS: UMA PERSPECTIVA DE PLANEJAMENTO ADAPTATIVO

LEONARDO RABELLO DA SILVA 27 June 2005 (has links)
[pt] O dinamismo das inovações tecnológicas e as constantes mudanças nos cenários geopolíticos mundiais têm causado crescente turbulência na maior parte dos ambientes em que as organizações da indústria do petróleo estão inseridas. Assim, torna-se vital para o crescimento e sobrevivência dessas organizações o estabelecimento de um processo de planejamento e gestão capaz de oferecer respostas flexíveis às diversas exigências ambientais. Nesse contexto, a presente Dissertação objetiva avaliar os sistemas de gestão e planejamento da Unidade de Negócio Refinaria Duque de Caxias - UN-REDUC, da Petrobras, analisando-os à luz dos princípios do Planejamento Adaptativo e sugerindo a implementação de ações que os aprimorem. Para atingir esse objetivo, foi realizado, além de revisão bibliográfica, um estudo de caso nessa refinaria, que subsidiou as análises do trabalho. Os principais instrumentos de pesquisa utilizados nesse estudo de caso foram a análise documental e a realização de entrevistas semi-estruturadas com os principais atores envolvidos no processo de formulação e implementação dos processos de planejamento e gestão da empresa, além da observação direta desses processos. O trabalho forneceu subsídios para ações já implementadas e para apresentação de propostas visando a tradução dos princípios do Planejamento Adaptativo no cotidiano da UN-REDUC. Como resultado desta pesquisa, produziu-se não apenas a análise pretendida, mas também a proposição e implementação de ações que visam o aperfeiçoamento dos processos considerados. / [en] The dynamism of the technology innovation and the constant changes in the worldwide geopolitical scenarios are contributing to develop a increasing turbulence in a great deal of the environments in which the petroleum organizations are situated. Therefore, the unique way for a growing future and a survival perspective for these organizations is the establishment of a management and planning process capable of disposing flexible answers to the unclear exigences of the environments. In this context this Dissertation intends to analyze the management and planning systems of the Duque de Caxias Refinery Unity - UN-REDUC, of Petrobras, comparing them with the Adaptive Planning principles and suggesting and implementing actions in order to improve these systems. This objective has been conquered with a bibliographic review and a case study in this Refinery in which the analysis of the survey has been realized. The principal survey instruments used in this case study are documental analysis and interviews with the protagonists of the management and planning Refinery processes, besides the direct observation of these processes. The job supported actions already implemented and proposals that aim a reproduction of the Adaptive Planning in the UN-REDUC daily activities. The result of the concluded survey reached not only the intended analysis, but also the proposal and the implementation of actions that desire the development of the considered processes.
60

On Derailment-Worthiness in Rail Vehicle Design : Analysis of vehicle features influencing derailment processes and consequences

Brabie, Dan January 2007 (has links)
This thesis aims at systematically studying the possibilities of minimizing devastating consequences of high-speed rail vehicle derailments by appropriate measures and features in the train design including the running gear. Firstly, an empirical database is established containing as much relevant information as possible of past incidents and accidents that have occurred at substantial running speeds due to mechanical failure close to the interface between the running gear and the track. Other causes that ultimately brought the train in a derailed condition are also covered. Although various accidental circumstances make each derailment a unique event, certain patterns appear to emerge which lead to several critical vehicle parameters capable of influencing the outcome of a derailment or preventing a derailment to occur. Secondly, the possibility of preventing wheel climbing derailments after an axle journal failure is studied by implementing mechanical restrictions between wheelsets and bogie frame. In this respect, a multi body system (MBS) computer model is developed to account for such an axle failure condition, which is successfully validated on the basis of two authentic passenger car events. In order to study the overall post-derailment vehicle behaviour, in particular the wheelsets’ vertical motion and lateral deviation on sleepers, a comprehensive MBS post-derailment module is developed and implemented in the commercially available software GENSYS. The model detects wheel-sleeper impact conditions and applies valid force resultants calculated through linear interpolation based on a pre-defined look-up table. The table was constructed through exhaustive finite element (FE) wheel to concrete sleeper impact simulations utilising the commercially available software LS-DYNA. The MBS post-derailment module has been validated successfully in several stages, including a correct prediction of the derailing wheelset’s trajectory over ten consecutive sleepers in comparison with an authentic passenger vehicle derailment event. An extensive simulation analysis on the feasibility of utilizing alternative substitute guidance mechanisms attached to the running gear on rail vehicles is presented, as means of minimizing the lateral deviation. Three low-reaching guidance mechanisms attached onto the running gear (bogie frame, brake disc and axle journal box) are analysed in terms of geometrical parameters for a successful engagement with the rail in order to prevent large lateral deviations after twelve different derailment scenarios. Three conventional coupled passenger trailing cars are investigated in terms of lateral deviation and vehicle overturning tendency after derailments on tangent and curved track. This is performed as a function of various vehicle design features and parameters such as: maximum centre coupler yaw angle, carbody height of centre of gravity, coupler height and additional running gear features. In a similar manner, the articulated train concept is investigated in terms of the post-derailment vehicle behaviour as a function of different inter-carbody damper characteristics and running gear features. / QC 20100701

Page generated in 0.07 seconds