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Nivellerande vinschsystem till ett vågkraftverk / Self leveling wave power converter winch systemHenningsson, Nils, Sjöberg, Marcus January 2019 (has links)
Detta projekt undersöker konstruktionsmöjligheterna för ett nivellerande vinschsystem till ett vågkraftverk. Kedjekonstruktionen till detta vinschsystem består av länkar med låg tolerans för vrid- och skjuvspänningar och har begränsad böjlighet vilket innebär att vinschsystemet behöver kunna vinkelkompensera för att kedjan inte ska brista. Initialt togs flera koncept fram genom att utvärdera en kravspecifikation och se vilka problem som fanns. Dessa konceptförslag modellerades sedan i Solid Edge och en ny utvärdering gjordes där förslagen utvärderades med avseende på komplexitet, vinkelstyrning, servicebarhet och energiåtgång från styrsystemen. Det förslag som var mest lovande utifrån denna utvärdering består av en vagga i vilken vinschtrumman är upphängd. Lutningen av denna vagga kan styras av två motorer och rotationsrörelsen styrs av ett rälssystem med boggier. Detta förslag vidareutvecklades sedan med hjälp av ANSYS Workbench för att göra konstruktionen lättare, undersöka utmattningsproblem samt se var spänningskoncentrationer uppstår. Från denna analys togs kravprofiler fram för ett antal komponenter som konstruktionen kräver för att kunna drivas. Vidare analys av växel, motor, lager samt energiåtgång kommer krävas för att utvärdera om hurvida konstruktionen är lönsam att bygga. / This project examines the design possiblilites for a self-leveling winch system for a wave power converter. The chain design for this winch consists of links with limited resistance to torsional shear and bending shear stress and with limited bending capabilities, which requires the winch construction to be able to compensate for angular changes to prevent the chain from breaking. Initially several designs were made by evaluating a specification of requirements and by examining the problems facing a winch based wave power converter. These designs were modelled in Solid Edge and evaluated based on complexity, angular steering, servicability and energy requirements for the control systems. The most promising of these designs is composed of a cradle in which the winch drum is mounted. The inclination of the cradle is controlled by electric motors and the rotation is controlled by a rail system with boggies. The design was then further improved upon by utilising ANSYS Workbench to decrease the mass of the design, examining problems related to fatigue failure, and studying stress concentrations. Based on this analysis a set of requirements were specified for a number of key components required for controlling the winch system. Further analysis of the transmission, motor, bearings and energy requirements for the control systems will be needed to evaluate wether the design is profitable to build.
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Particulate Debris Spreading and CoolabilityBasso, Simone January 2017 (has links)
In Nordic design of boiling water reactors, a deep water pool under the reactor vessel is employed for the core melt fragmentation and the long term cooling of decay heated corium debris in case of a severe accident. To assess the effectiveness of such accident management strategy the Risk-Oriented Accident Analysis Methodology has been proposed. The present work contributes to the further development of the methodology and is focused on the issue of ex-vessel debris coolability. The height and shape of the porous debris bed are among the most important factors that determine if the debris can be cooled by natural circulation of water. The bed geometry is formed in the process of melt release, fragmentation, sedimentation and packing of the debris in the pool. Bed shape is affected by the coolant flow that induces movement of particles in the pool and after settling on top of the bed. The later one is called debris bed self-leveling phenomenon. In this study, the self-leveling was investigated experimentally and analytically. Experiments were carried out in order to collect data necessary for the development of a numerical model with an empirical closure. The self-leveling model was coupled to a model for prediction of the debris bed dryout. Such coupled code allows to calculate the time necessary to have a coolable configuration of the bed. The influence of input parameters was assessed through sensitivity analysis in order to screen out the less influential parameters. Results of the risk analysis are reported as complementary cumulative distribution functions of the conditional containment failure probability (CCFP). Sensitivity analyses identified: effective particle diameter and debris bed porosity as the parameters that provide the largest contribution to the CCFP uncertainty. It is found that the effect of the initial maximum height of the bed on the CCFP is reduced by the self-leveling. / Kokvattenreaktorer av nordisk typ har en djup vattenbassäng under reaktorkärlet som kan utnyttjas för att kyla härdsmältan och de fragmenterade härdresterna vid ett svårt reaktorhaveri. För att bedöma effektiviteten av en sådan haverihantering har man föreslagit användande av en riskorienterad metodik för haverianalysen (ROAAM, från engelska ”Risk-Oriented Accident Analysis Methodology”). Föreliggande projekt fokuserar på kylbarhet hos härdresterna utanför reaktortanken och bidrar till den pågående vidareutvecklingen av ROAAM till ROAAM+. Höjden på och formen för den porösa ansamlingen av härdrester (här också kallad partikelbädd) är bland de viktigaste faktorerna som avgör om resteffekten kan kylas bort med hjälp av naturlig cirkulation av vattnet i bassängen. Ansamlingens geometriska form skapas under hela processen från utsläpp av härdsmältan via fragmentering och sedimentering i bassängens botten. Formen kan sedan förändras med tiden genom att partiklar rör sig och omfördelas i kylflödet. Detta fenomen kallas en självnivellerande process. I detta arbete studeras denna självnivellerande process experimentellt och analytiskt. Experimenten utfördes i en särskild experimentuppställning utformad för att att samla in data och parametrar som behövs för att simulera fenomenet och utveckla en beräkningsmodell som sluts empiriskt. Denna modell kopplades sedan till en modell för beräkning av dryout i partikelbädden. Genom denna koppling av de två beräkningsprogrammen är det är möjligt att beräkna tiden för partikelbädden att nå en kylbar konfiguration. Inverkan av variationer i modellens indata studeras med hjälp av känslighetsanalys. Härigenom identifierades de minst inflytelserika parametrarna såsom effektiv drifttid, partikeldensitet, experimentell ovisshet i de empiriska samband som används för att sluta modellen, samt omlokaliseringstid efter det att reaktorn snabbstoppats (SCRAM). Dessa parametrar avfördes sedan från den fortsatta känslighetsanalysen. Ett artificiellt neuralt nätverk tränades för att användas i stället för den kopplade koden och möjliggöra den beräkningseffektivitet som krävs för att studera hur osäkerheter i indata förs vidare i riskanalysen. Resultaten är presenterade i form av komplementära, kumulativa fördelningsfunktioner för den betingade sannolikheten för brott på reaktorinneslutningen (CCFP, från engelska ”conditional containment failure probability”). Det visas att CCFP kan variera inom ett brett område beroende på de valda kombinationerna av frekvensfunktioner för ingångsparametrarna. Resultaten visar att effektiv partikeldiameter och hög porositet är de två parametrar som ger de största bidragen till osäkerheten i CCFP. Vi har också funnit att fenomenet självnivellering har en gynnsam inverkan på CCFP och leder till lägre utsläppsrisk. Det vore värdefullt att förfina de modeller som beskriver bildandet av den initiala partikelbädden. Detta är särskilt viktigt i de scenarier där det finns kort tid för självnivellering innan partikelbädden börjar smälta igen, dvs när man har relativt hög initial temperatur i partikelbädden och/eller hög specifik värmeeffekt. / <p>QC 20170315</p> / APRI
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Modelo de programação da produção nivelada para produção enxuta em ambiente ETO com alta variedade de produtos e alta variação de tempos de ciclo / Leveled production programming model for lean production in ETO environment with high variety of products and high variation of cycle timesStefanelli, Paola 17 January 2011 (has links)
A Produção Enxuta vêm exercendo um papel cada vez mais importante durante as transformações das organizações em busca de competitividade no mercado. O nivelamento de produção surge como uma das mais importantes características da Produção Enxuta. O ambiente de produção com alta variedade de produtos, tipologia de produção Engineer to Order e com alta variação de tempo de ciclo está se tornando cada vez mais significativo no mercado atual e possui as mesmas necessidades de nivelamento da produção que os ambientes de produção nos quais tradicionalmente são aplicados os conceitos de Produção Enxuta. Este trabalho propõe um modelo de programação nivelada da produção para o tipo de ambiente de produção citado e descreve uma aplicação utilizando o método apresentado em uma empresa de vidros para a construção civil. / Lean Production has played an increasingly important role in the transformation of organizations for market competitiveness. The production leveling appears as one of the most important characteristics of Lean Production. The production environment with high variety of products, production typology Engineer to Order, with high variation of cycle time is becoming increasingly significant in today\'s market and has the same needs leveling production environments in which traditionally applied the concepts of Lean Production. This paper proposes a programming model of the production level for the kind of production environment cited and describes an application using the method presented in a glass company for civil construction.
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Automation of front-end loaders : electronic self leveling and payload estimationYung, I January 2017 (has links)
A growing population is driving automatization in agricultural industry to strive for more productive arable land. Being part of this process, this work is aimed to investigate the possibility to implement sensor-based automation in a particular system called Front End Loader, which is a lifting arms that is commonly mounted on the front of a tractor. Two main tasks are considered here, namely Electronic Self Leveling (ESL) and payload estimation. To propose commercially implementable solutions for these tasks, specific objectives are set, which are: 1) to propose a controller to perform ESL under typical disturbances 2) to propose a methodology for payload estimation considering realistic estimation conditions. Lastly, aligned with these goals, 3) to propose models for the Front End Loader under consideration for derivation of solutions of the specified tasks. The self-leveling task assists farmers in maintaining the angular position of the mounted implements, e.g. a bale handler or a bucket, with respect to the ground when the loader is manually lifted or lowered. Experimental results show that different controllers are required in lifting and lowering motions to maintain the implement's angular position with a required accuracy due to principle differences in gravity impact. The gravity helps the necessary correction in lifting motion, but works against the correction in lowering motions. This led us to propose a controller with a proportional term, a discontinuous term and an on-line disturbance estimation and compensation as well as the tuning procedure to achieve a 2 degrees tracking error for lowering motions in steady state. The proposed controller shows less sensitive performance to lowering velocity, as the main disturbance, in comparison to a linear controller. The second task, payload estimation, assists farmers to work within safety range as well as to work with a weight measurement tool. A mechanical model derived based on equations of motion is improved by a pressure based friction to sufficiently accurately represent the motion of the front end loader under consideration. The proposed model satisfies the desired estimation accuracy of 2\% full scale error in a certain estimation condition domain in constant velocity regions, with off-line calibration step and off-line payload estimation step. An on-line version of the estimation based on Recursive Least Squares also fulfills the desired accuracy, while keeping the calibration step off-line.
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Modelo de programação da produção nivelada para produção enxuta em ambiente ETO com alta variedade de produtos e alta variação de tempos de ciclo / Leveled production programming model for lean production in ETO environment with high variety of products and high variation of cycle timesPaola Stefanelli 17 January 2011 (has links)
A Produção Enxuta vêm exercendo um papel cada vez mais importante durante as transformações das organizações em busca de competitividade no mercado. O nivelamento de produção surge como uma das mais importantes características da Produção Enxuta. O ambiente de produção com alta variedade de produtos, tipologia de produção Engineer to Order e com alta variação de tempo de ciclo está se tornando cada vez mais significativo no mercado atual e possui as mesmas necessidades de nivelamento da produção que os ambientes de produção nos quais tradicionalmente são aplicados os conceitos de Produção Enxuta. Este trabalho propõe um modelo de programação nivelada da produção para o tipo de ambiente de produção citado e descreve uma aplicação utilizando o método apresentado em uma empresa de vidros para a construção civil. / Lean Production has played an increasingly important role in the transformation of organizations for market competitiveness. The production leveling appears as one of the most important characteristics of Lean Production. The production environment with high variety of products, production typology Engineer to Order, with high variation of cycle time is becoming increasingly significant in today\'s market and has the same needs leveling production environments in which traditionally applied the concepts of Lean Production. This paper proposes a programming model of the production level for the kind of production environment cited and describes an application using the method presented in a glass company for civil construction.
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Optimization Of Time-cost-resource Trade-off Problems In Project Scheduling Using Meta-heuristic AlgorithmsBettemir, Onder Halis 01 August 2009 (has links) (PDF)
In this thesis, meta-heuristic algorithms are developed to obtain optimum or near optimum solutions for the time-cost-resource trade-off and resource leveling problems in project scheduling. Time cost trade-off, resource leveling, single-mode resource constrained project scheduling, multi-mode resource constrained project scheduling and resource constrained time cost trade-off problems are analyzed.
Genetic algorithm simulated annealing, quantum simulated annealing, memetic algorithm, variable neighborhood search, particle swarm optimization, ant colony optimization and electromagnetic scatter search meta-heuristic algorithms are implemented for time cost trade-off problems with unlimited resources. In this thesis, three new meta-heuristic algorithms are developed by embedding meta-heuristic algorithms in each other. Hybrid genetic algorithm with simulated annealing presents the best results for time cost trade-off.
Resource leveling problem is analyzed by five genetic algorithm based meta-heuristic algorithms. Apart from simple genetic algorithm, four meta-heuristic algorithms obtained same schedules obtained in the literature. In addition to this, in one of the test problems the solution is improved by the four meta-heuristic algorithms.
For the resource constrained scheduling problems / genetic algorithm, genetic algorithm with simulated annealing, hybrid genetic algorithm with simulated annealing and particle swarm optimization meta-heuristic algorithms are implemented. The algorithms are tested by using the project sets of Kolisch and Sprecher (1996). Genetic algorithm with simulated annealing and hybrid genetic algorithm simulated annealing algorithm obtained very successful results when compared with the previous state of the art algorithms.
120-activity multi-mode problem set is produced by using the single mode problem set of Kolisch and Sprecher (1996) for the analysis of resource constrained time cost trade-off problem. Genetic algorithm with simulated annealing presented the least total project cost.
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La lecture romanesque comme déclencheur de l'écriture poétique : développement, validation et essai d'un outil pédagogique et papier-crayon pour favoriser l'expression des émotions chez les adolescents /Delisle, Richard, January 2006 (has links)
Thèse (M.Ed.) -- Université du Québec à Chicoutimi, 2006. / La p. de t. porte en outre: Mémoire présenté à l'Université du Québec à Chicoutimi comme exigence partielle de la maîtrise en éducation (M.A.). CaQCU Bibliogr.: f. [76]-81. Document électronique également accessible en format PDF. CaQCU
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Evolution des composantes du niveau marin à partir d'observations de marégraphie effectuées depuis la fin du 18ème siècle en Charente-Maritime / Changes in sea level components from tide gauge data since the end of the 18th century along the Charente-Maritime French Atlantic coastGouriou, Thomas 26 March 2012 (has links)
Les estimations de la remontée générale du niveau de la mer, de l’ordre de 17 ± 2 cm sur le siècle dernier, masquent une réalité très variable d’une région à l’autre. Qu’en est-il du littoral charentais ? Des séries temporelles de plus de 40-50 ans sont souvent indispensables pour tirer des tendances fiables à long terme sur les composantes du niveau marin : niveau moyen de la mer, ondes de marée et effets météorologiques. Or, de nombreux lots de mesures marégraphiques du littoral charentais « sommeillaient » dans les centres d’archive français, i.e. : La Rochelle-Vieux port (1775-1892), La Rochelle-La Pallice (1885-auj.), île d’Aix (1824-auj.), fort Enet (1859-1873), fort Boyard(1873-1909) et Cordouan (1812-1994). Les objectifs de nos travaux de recherche étaient multiples : inventorier,sauvegarder et numériser des lots de mesures historiques du niveau marin, puis construire des séries temporelles recomposées à partir de ces lots de mesures hétérogènes, temporellement et spatialement, et enfin les exploiter pour mieux décrire et comprendre l’évolution à long terme du niveau de la mer. La qualité des trois séries construites (LaRochelle : 1775-auj. ; Aix-Enet-Boyard : 1824-auj. ; et Cordouan : 1812-1994) a ensuite été éprouvée en détail afin d’évaluer le niveau de précision de notre reconstruction. A partir de ces séries inédites, nous avons pu étudier l’évolution des composantes du niveau marin. Suite à ces travaux, nous fournissons un inventaire le plus exhaustif possible détaillant les mesures de 25 observatoires de Charente-Maritime, de 1775 à aujourd’hui. Les données des séries temporelles ainsi que des éléments permettant d’apprécier leur qualité seront bientôt disponibles en ligne sur REFMAR (refmar.shom.fr), SONEL (www.sonel.org) et au PSMSL (www.psmsl.org). Nos résultats positifs nous ont permis de reconstruire une série encore plus globale, celle du pertuis d’Antioche, à partir des moyennes mensuelles du niveau marin des séries de La Rochelle et d’Aix-Enet-Boyard. Parmi les résultats marquants obtenus,le niveau moyen de la mer s’est élevé de +1,38 ± 0,08 mm/an dans le pertuis d’Antioche sur la période 1860-2010.Ce résultat est cohérent avec Liverpool (+1,2 ± 0,1 mm/an sur la période 1858-1997 [Woodworth, 1999a]) et avec les récents résultats suggérant que l’élévation du niveau marin sur les côtes atlantiques européennes est moins importante qu’au niveau mondial (+1,7 ± 0,3 mm/an sur la période 1870-2004 [Church & White, 2006]). / Global sea level rise, which is estimated at 17 ± 2 cm over the last century, does not reflect the differences of the sealevel evolution between places across the world. What is the situation along the Charente-Maritime French Atlanticcoast? Time series covering a period of at least 40-50 years are vital to establish reliable long-term trends of sealevel components: mean sea level, tidal constituents and meteorological effects. Many tide gauge data sets of the Charente-Maritime coast have recently been rediscovered in archives: La Rochelle-Vieux port (1775-1892), La Rochelle-La Pallice (1885-today), île d’Aix (1824-today), fort Enet (1859-1873), fort Boyard (1873-1909) and Cordouan (1812-1994). The aims of this thesis were firstly to inventory, to rescue and to digitize historical sea leveldata sets. Secondly, those data sets were put back together in order to construct continuous time series, which have been analysed and led to a better description of long-term sea level changes. In this way, three time series were constructed (La Rochelle: 1775-today; Aix-Enet-Boyard: 1824-today; and Cordouan: 1812-1994) and have been deeply examined to assess the construction validity and quality. From these new time series, we could estimate changes of sea level components. Thanks to this research work, we have been able to provide an inventory as exhaustive as possible, with detailed measurements of twenty five Charente-Maritime’s stations from 1775 to nowadays. All those data will be soon available on REFMAR (refmar.shom.fr), SONEL (www.sonel.org) and PSMSL (www.psmsl.org) websites. From those positive results, we have been able to reconstruct a more global time series (Pertuis d’Antioche) from the monthly mean sea levels of La Rochelle and Aix-Enet-Boyard. Among our results, we can high light that the mean sea level trend on Pertuis d’Antioche is estimated at +1.38 ± 0.08 mm/year, from 1860 to 2010. This result is consistent with Liverpool’s trend (+1.2 ± 0.1 mm/year from 1858 to 1997[Woodworth, 1999a]) and also with recent results suggesting that sea level rise along the European Atlantic coasts isslower than global sea level rise (+1.7 ± 0.3 mm/year from 1870 to 2004 [Church & White, 2006]).
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Proposta de um modelo para alocação e nivelamento de recursos humanos integrados em projetos de tecnologia da informação / Proposal for a model of integrated allocation and leveling of human resources in information technology projectsCelkevicius, Roberto 29 March 2016 (has links)
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Previous issue date: 2016-03-29 / A critical aspect of IT management - Information Technology is the distribution of human resources across multiple projects competing for these resources. These features have specific skills and are shared among several areas. The allocation of these resources should be planned in order to minimize cost and time. Typically, the leveling of these resources is done in an after step, to control both idle time and overwork, which can result in rework, and new negotiations to adjust costs and time. To check how to solve these problems, the objective of this work is to propose a model of integrated allocation and leveling of human resources in IT projects in the planning phase. For this, a single case study was done and the analysis unit chosen was the board of IT infrastructure projects, with three management areas that meet different customers in a large enterprise IT outsourcing services. Project managers are responsible for the definition, negotiation and allocation of human resources, which they were the focus of the interviews. Through interviews and analysis of the organization's internal documents, it was analyzed the importance given to the critical path, resource constraints in terms of quantity and skills and interactions with departments and organization’s internal committees for the allocation and leveling process of human resources. As a result, a model was proposed for allocation and leveling of human resources in an integrated manner for IT projects. In this model, some components are identified as the critical path, the need of a management area of human resources capable to handle IT projects, which would maintain a centralized database with information availability, restrictions, vacations, days off and skills of human resources, associated with a committee of personnel allocation with regular meetings, for the final decisions of allocation and leveling of human resources in IT projects. Furthermore, it is proposed an index named allocation factor, which can be explored in future research as well as other research opportunities in software area which they are regarding allocation and leveling human resource systems itself, decision support systems and optimization algorithms such procedures. / Um aspecto crítico da gestão de TI – Tecnologia da Informação é a distribuição de recursos humanos entre vários projetos que competem por esses recursos. Esses recursos possuem competências específicas e são compartilhados entre várias áreas. A alocação desses recursos deve ser planejada, de maneira a minimizar custos e prazos. Normalmente, o nivelamento desses recursos é feito posteriormente para controlar tanto a ociosidade quanto o excesso de trabalho, o que pode implicar em retrabalho e novas negociações para adequar custos e prazo. Para verificar como resolver esses problemas, o objetivo deste trabalho é propor um modelo de alocação e nivelamento de recursos humanos integrados no planejamento de projetos de TI. Para isso, foi realizado um estudo de caso único e a unidade de análise escolhida foi a diretoria de projetos de infraestrutura de TI, com três gerências que atendem clientes distintos, em uma grande empresa de serviços de outsourcing de TI. Os gerentes de projetos são os responsáveis pela definição, negociação e alocação dos recursos humanos, sendo estes, o foco das entrevistas realizadas. Por meio de entrevistas e análise dos documentos internos da organização, analisou-se a importância dada ao caminho crítico, as restrições de recursos em termos de quantidade e competências e as interações com departamentos e comitês internos da organização no processo de alocação e nivelamento de recursos humanos. Como resultado, foi proposto um modelo para esta alocação e nivelamento em projetos de TI de maneira integrada. Neste modelo, fazem parte a identificação do caminho crítico, a necessidade da existência de uma área gestora dos recursos humanos capazes de trabalhar em projetos de TI, que manteria uma base de dados centralizada com informações de disponibilidade, restrições, férias, folgas e competências dos recursos humanos que, associada a um comitê de alocação de pessoas com reuniões periódicas, tomam as decisões finais de alocação e nivelamento de recursos humanos nos projetos de TI. Ainda, é proposto um índice que se denominou de fator de alocação, que pode ser explorado em pesquisas futuras, bem como, outras oportunidades de pesquisa na área de software em relação a sistemas de alocação e nivelamento de recursos humanos propriamente dito, sistemas de apoio de decisão e algoritmos de otimização desses procedimentos.
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Výzkum v oblasti anhydritových pojiv / Research in the Field of Anhydrite BindersBřicháčková, Jana January 2014 (has links)
The presented work deals with research in the field of sulfate binders on the anhydrite base. Conceptually, it is divided into a general theory of sulfate binders and anhydrite mortar compounds, which is describing in detail the using of anhydrite mortar compounds on the poured floor screeds, and then the experimental part, where is made the mineralogical analysis of seven different gypsum resources and subsequent is monitored the effect of two sulfate exciters on the achieved technological properties and hydration process.
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