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  • 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.
11

Direct Use Of Pgv For Estimating Peak Nonlinear Oscillator Displacements

Kucukdogan, Bilge 01 November 2007 (has links) (PDF)
DIRECT USE OF PGV FOR ESTIMATING PEAK NONLINEAR OSCILLATOR DISPLACEMENTS K&Uuml / &Ccedil / &Uuml / KDOGAN, Bilge Recently established approximate methods for estimating the lateral deformation demands on structures are based on the prediction of nonlinear oscillator displacements (Sd,ie). In this study, a predictive model is proposed to estimate the inelastic spectral displacement as a function of peak ground velocity (PGV). Prior to the generation of the proposed model, nonlinear response history analysis is conducted on several building models of wide fundamental period range and hysteretic behavior to observe the performance of selected demands and the chosen ground-motion intensity measures (peak ground acceleration, PGA, peak ground velocity, PGV and elastic pseudo spectral acceleration at the fundamental period (PSa(T1)). Confined to the building models used and ground motion dataset, the correlation studies revealed the superiority of PGV with respect to the other intensity measures while identifying the variation in global deformation demands of structural systems (i.e., maximum roof and maximum interstory drift ratio). This rational is the deriving force for proposing the PGV based prediction model. The proposed model accounts for the variation of Sd,ie for bilinear hysteretic behavior under constant ductility (&micro / ) and normalized strength ratio (R) associated with postyield stiffness ratios of = 0% and = 5%. Confined to the limitations imposed by the ground-motion database, the predictive model can estimate Sd,ie by employing the PGV predictions obtained from the attenuation relationships. This way the influence of important seismological parameters can be incorporated to the variation of Sd,ie in a fairly rationale manner. Various case studies are presented to show the consistent estimations of Sd,ie by the proposed model using the PGV values obtained from recent ground motion prediction equations.
12

Prise en compte de l‘influence de la culture organisationnelle pour la conduite des activités de conception collaboratives

Topliceanu, Genoveva Doinita 06 January 2010 (has links)
La conduite des systèmes de conception et le pilotage des projets consistent non seulement à allouer des ressources pour satisfaire au mieux les objectifs assignés au système et au projet, mais également à favoriser la collaboration entre les acteurs du système qu‘ils soient directement ou indirectement impliqués dans le projet. Lors de l‘évolution du système et pendant le déroulement du projet, les décideurs doivent pouvoir analyser la situation de conception existante et encourager l‘apparition d'une situation de collaboration si le besoin s‘en fait sentir. L‘objectif de cette thèse est de définir les concepts permettant d‘analyser et de faire évoluer le système de conception. Pour ce faire nous articulons nos travaux autour d‘un modèle de référence pour l‘évaluation des systèmes de conception. Nous complétons ce modèle en intégrant les influences, à chaque niveau décisionnel, de la culture organisationnelle. Nous montrons comment la culture organisationnelle peut jouer un rôle non négligeable auprès des acteurs de l‘entreprise en vue de l‘atteinte des objectifs fixés par celle-ci. Nous obtenons ainsi, un modèle adapté à la conduite des systèmes de conception et au pilotage des projets de conception dans un environnement multi-acteurs, multi-disciplinaires et multi-projets. Notre modèle positionne la performance des systèmes de conception dans le cadre plus large de la performance globale de l'entreprise en décrivant les éléments du contexte de l‘entreprise et la culture organisationnelle de celle-ci qui vont influencer la conception. Une étude de cas réelle menée au sein d‘une entreprise espagnole montre en quoi il est nécessaire de prendre en considération la culture organisationnelle dès lors que l‘on souhaite mettre en place une stratégie dans une entreprise en vue de concevoir un nouveau produit. / The design systems management and the project management have not only to concern resources allocation process to satisfy the objectives assigned, but also to promote collaboration between the actors of the system which could be involved in the project or not. During the system evolution and the project, the leaders will analyze the real state of design conditions and stimulate the collaborating conditions when it is necessary. Objective of this thesis is to define concepts allowing analysing, managing and making evolve the design system. To achieve this objective we articulate our research around a reference model to evaluate design system. We complete this model by integrating influences, at each decisional level, of the organizational culture. We show how the organizational culture could have an important influence in the actors‘ way of life in the company. We obtain a model adapted to a multi-actor, multi-disciplinary and multi-project environment. Our model positioned the design systems in the more global context of the performance of the enterprise by describing elements of the environment of enterprise and the organizational culture which will have an influence on the design system. A real case study in a Spanish company shows how organizational culture could impact the strategy of a company when it wants to develop a new product.
13

Radial turbine expander design, modelling and testing for automotive organic Rankine cycle waste heat recovery

Alshammari, Fuhaid January 2018 (has links)
Since the late 19th century, the average temperature on Earth has risen by approximately 1.1 °C because of the increased carbon dioxide (CO2) and other man-made emissions to the atmosphere. The transportation sector is responsible for approximately 33% of the global CO2 emissions and 14% of the overall greenhouse gas emissions. Therefore, increasingly stringent regulations in the European Union require CO2 emissions to be lower than 95 gCO₂/km by 2020. In this regard, improvements in internal combustion engines (ICEs)must be achieved in terms of fuel consumption and CO2 emissions. Given that only up to 35% of fuel energy is converted into mechanical power, the wasted energy can be reused through waste heat recovery (WHR) technologies. Consequently, organic Rankine cycle (ORC) has received significant attention as a WHR technology because of its ability to recover wasted heat in low- to medium-heat sources. The Expansion machine is the key component in ORC systems, and its performance has a direct and significant impact on overall cycle efficiency. However, the thermal efficiencies of ORC systems are typically low due to low working temperatures. Moreover, supersonic conditions at the high pressure ratios are usually encountered in the expander due to the thermal properties of the working fluids selected which are different to water. Therefore, this thesis aims to design an efficient radial-inflow turbine to avoid further efficiency reductions in the overall system. To fulfil this aim, a novel design and optimisation methodology was developed. A design of experiments technique was incorporated in the methodology toexplorethe effects of input parameters on turbine performance and overall size. Importantly, performance prediction modelling by means of 1D mean-line modelling was employed in the proposed methodology to examine the performance of ORC turbines at constant geometries. The proposed methodology was validated by three methods: computational fluid dynamics analysis, experimental work available in the literature, and experimental work in the current project. Owing to the lack of actual experimental works in ORC-ICE applications, a test rig was built around a heavy-duty diesel engine at Brunel University London and tested at partial load conditions due to the requirement for a realistic off-high representation of the performance of the system rather than its best (design) point, while taking into account the limitation of the engine dynamometer employed. Results of the design methodology developed for this projectpresented an efficient single-stage high-pressure ratio radial-inflow turbine with a total to static efficiency of 74.4% and an output power of 13.6 kW.Experimental results showed that the ORC system had a thermal efficiency of 4.3%, and the brake-specific fuel consumption of the engine was reduced by 3%. The novel meanlineoff designcode (MOC) was validated with the experimental works from three turbines. In comparison with the experimental results conducted at Brunel University London, the predicted and measured results were in good agreement with a maximum deviation of 2.8%.
14

Implementation Of A Low-cost Smart Camera Apllication On A Cots System

Baykent, Hayri Kerem 01 January 2012 (has links) (PDF)
The objective of this study is to implement a low-cost smart camera application on a Commercial off the Shelf system that is based on Texas Instrument&rsquo / s DM3730 System on Chip processor. Although there are different architectures for smart camera applications, ARM plus DSP based System on Chip architecture is selected for implementation because of its different core abilities. Beagleboard-XM platform that has an ARM plus DSP based System on Chip processor is chosen as Commercial off the Shelf platform. During this thesis, firstly to start-up the Commercial off the Shelf platform the design steps of porting an embedded Linux to ARM core of System on Chip processor is described. Then design steps that are necessary for implementation of smart camera applications on both ARM and DSP cores in parallel are given in detail. Furthermore, the real-time image processing performance of the Beagleboard-xM platform for the smart camera applications is evaluated with simple implementations.
15

[en] EVALUATING THE INTERPLAY BETWEEN BIM, LEAN AND SUSTAINABILITY CONCEPTS IN BUILDING DESIGN / [pt] AVALIAÇÃO DO INTER-RELACIONAMENTO ENTRE OS CONCEITOS BIM, LEAN E SUSTENTABILIDADE EM PROJETOS DE EDIFICAÇÕES

PEDRO SAIEG FARIA 25 April 2018 (has links)
[pt] O principal objetivo deste estudo foi avaliar e validar como funcionalidades da Modelagem da Informação da Construção (BIM) podem interagir com princípios da construção enxuta para contribuir para o desenvolvimento sustentável em projetos de construção e alcançar projetos de maior qualidade. Para este fim, primeiramente uma breve revisão de cada um destes conceitos foi introduzida, seguida por uma extensiva e estruturada revisão da literatura, buscando combinações par a par destes tópicos. Os resultados desta revisão deram origem à uma matriz que que consolidou as interrelações, que foram destacadas e explicadas. Para validar algumas destas interrelações, um plug-in foi proposto e implementado em um ambiente de visualização BIM para ajudar o usuário a decidir pelo melhor projeto dentre diferentes alternativas, considerando também a perspectiva do usuário em termos do que mais gera valor ao projeto. Para ilustrar e validar a usabilidade e importância do plug-in, o projeto de um galpão com determinados requerimentos foi considerado. Quatro alternativas de projeto foram modeladas considerando diferentes tipos de superestrutura e envelope das edificações, bem como variados materiais. Estes modelos foram exportados como arquivos IFC e então importados no ambiente BIM. Através do plug-in desenvolvido, foi então importada uma base de dados externa e calculados os indicadores de custos gerais, emissões de CO2 e comforto térmico para cada modelo baseados nos dados contidos nos elementos e na base de dados importada. Finalmente, foram consideradas ponderações inseridas por usuários para cada indicador e exibidos os resultados em forma de gráficos, indicando a melhor opção através de um Método de Decisão de Múltiplos Atributos. Apesar de os modelos utilizados nesta pesquisa terem sido hipotéticos e mais indicadores serem necessários para melhores resultados, foi possível verificar que análises automatizadas podem otimizar tarefas de tomada de decisão que em outras circunstâncias seriam ineficientes e imprecisas. Desta forma, algumas das interações percebidas foram validadas e a importância da integração entre os conceitos foi confirmada. / [en] The main purpose of this study was to evaluate and validate how Building Information Modeling functionalities could interact with lean construction principles to support sustainable development in building design and deliver higher quality projects. To that end, first a brief introduction to each of these concepts was introduced, followed by an extensive and structured literature research looking for pairwise combination of these topics. The results of this review generated a matrix that brought up interactions, which were highlighted and explained. To further validate some of these interrelationships, a plug-in was proposed and implemented on a BIM enabled visualization environment to help the user decide the best design between alternatives, while considering his perspective on what generates value to the project. To illustrate and validate the usability and importance of the plug-in, the design of a warehouse with certain requirements was considered. Four design alternatives were modelled considering different types of superstructures along with the building envelope and varied types of materials. These models were exported as IFC files and then imported to the BIM environment. The plug-in then imported an external database and calculated general costs, CO2 emissions and thermal comfort indicators for each model based on data contained on elements and the imported database. Finally, it considered user weightings on each indicator and graphically displayed results indicating which of the options would be the best through a Multiple Attribute Decision Method. Even though the used models were hypothetical and more indicators would be required for more robust results, it was possible to verify that automated analysis considering indicators can optimize decision making tasks that otherwise would be inefficient and innacurate. This way, some of the perceived interactions were validated and the importance of integrating these concepts was confirmed.
16

[pt] O PAPEL MODERADOR DA INTELIGÊNCIA CULTURAL NA RELAÇÃO DAS CARACTERÍSTICAS DOS GERENTES DE PROJETO E O SUCESSO DOS PROJETOS / [en] THE MODERATING ROLE OF CULTURAL INTELLIGENCE IN THE RELATION OF PROJECT MANAGERS CHARACTERISTICS AND THE SUCCESS OF PROJECTS

BERNARDO PARAISO DE CAMPOS SERRA 27 July 2021 (has links)
[pt] Esta tese investiga o papel moderador da inteligência cultural na relação das características dos gerentes de projeto e o sucesso dos projetos. A tese é composta por dois estudos principais: (a) em primeiro momento, por meio de um estudo bibliométrico com uso de citação, cocitação, pareamento e análise fatorial, buscou-se entender o que tem sido estudado em inteligência cultural e qual estrutura intelectual e a pesquisa atual do tema. (b) no segundo estudo, por meio de pesquisa com gestores de projetos e utilização dos dados em uma regressão, objetivou-se investigar a influência do gerente no desempenho, considerando suas características individuais, em especial, a inteligência cultural, como uma capacidade que pode alterar o comportamento do gerente e o desempenho de um projeto. Como contribuição estão presentes o entendimento do que tem sido estudado em inteligência cultural e a estrutura intelectual bem como quais as implicações das carateristicas individuais, em especial a inteligência cultural, de um gestor de projetos no sucesso de um projeto. / [en] This thesis investigates the moderating role of cultural intelligence in the relationship between project managers characteristics and project success. The thesis is composed of two main studies: (a) first, through a bibliometric study using citation, cocitation, pairing and factor analysis, I sought to understand what has been studied in cultural intelligence and what intellectual structure and current research on the topic. (b) in the second study, through research with project managers and the use of data in a regression, my objective was to investigate the manager s influence on performance, considering their individual characteristics, in particular, cultural intelligence, as a capacity that can change the behavior of the manager and the performance of a project. As a contribution are present the understanding of what has been studied in cultural intelligence and the intellectual structure as well as the implications of individual characteristics, especially cultural intelligence, of a project manager in the success of a project.
17

Design in the Modern Age: Investigating the Role of Complexity in the Performance of Collaborative Engineering Design Teams

Ambler, Nathaniel Palenaka 12 June 2015 (has links)
The world of engineering design finds itself at a crossroads. The technical and scientifically rooted tools that propelled humankind into the modern age are now insufficient as evidenced by a growing number of failures to meet design expectations and to deliver value for users and society in general. In the empirical world, a growing consensus among many design practitioners has emerged that engineering design efforts are becoming too unmanageable and too complex for existing design management systems and tools. One of the key difficulties of engineering design is the coordination and management of the underlying collaboration processes. Development efforts that focus on the design of complex artefacts, such as a satellite or information system, commonly require the interaction of hundreds to thousands of different disciplines. What makes these efforts and the related collaboration processes complex from the perspective of many practitioners is the strong degree of interdependency between design decision-making occurring, often concurrently, across multiple designers who commonly reside in different organizational settings. Not only must a design account for and satisfice these dependencies, but it must remain also acceptable to all design participants. Design in effect represents a coevolution between the problem definition and solution, with a finalized design approach arising not from a repeatable series of mathematical optimizations but rather through the collective socio-technical design activities of a large collaboration of designers. Despite the importance of understanding design as a socio-technical decision-making entity, many of the existing design approaches ignore socio-technical issues and often view them as either too imprecise or too difficult to consider. This research provides a performance measurement framework to explore these factors by investigating design as a socio-technical complex adaptive collaborative process between the designer, artefact, and user (DAU). The research implements this framework through an agent-based model, the Complex Adaptive Performance Evaluation Method for Collaboration Design (C2D). This approach allows a design management analyst to generate insights about potential design strategies and mechanisms as they relate to design complexity by examining the simulated performance of a design collaboration as it explores theoretical design fitness landscapes with various degrees of ruggedness. / Ph. D.
18

Tunable broadband integrated circuits for adaptive optical interconnects

Henker, Ronny, Schoeniger, David, Belfiore, Guido, Szilagyi, Lazlo, Pliva, Jan, Khafaji, Mahdi, Ellinger, Frank, Nieweglowski, Krzysztof, Bock, Karlheinz, Tiedje, Tobias 06 September 2019 (has links)
To accommodate the growing demand on higher speeds, low latencies and low energy consumption, the interconnections within and between data centers are supposed to be implemented as optical fiber and waveguide interconnects in future. Optical fiber interconnects provide several advantages over their electrical counterparts as they enable higher bandwidth densities and lower losses at high frequencies over distances longer than few centimeters. However, nowadays optical fiber interconnects are usually not very energy-efficient. The systems in optical networks are mostly optimized for running at their peak performance to transmit the information with the highest available error-free data rate. But the work load of a processor system and hence of an optical link is not constant and varies over time due to the demand of the running applications and users. Therefore, optical interconnects consume the same high power at all times even if lower performance is required. In this paper a new method for the tuning of optical interconnects for on-board and board-to-board optical communication is described. In this way the performance of the transceiver systems of the link is adapted to the present transmission workload and link requirements. If for example lower data rates are required, the bandwidth and therefore the power consumption of the systems can be reduced. This tuning is enabled by the integrated circuitry of the optical link. Different methods for such an adaptive tuning are described and several practical examples are reviewed. By using adaptive bandwidth reduction in the circuits, more than 50 % of the consumed power can be saved. These savings can result in tremendous reductions of the carbon footprint and of the operating costs produced by data centers.
19

Définition des indicateurs de l'efficience inventive pour caractériser les activités inventives en R&D : application au domaine de l’automobile / Key performance indicators of inventive activities for characterizing technological design in R&D : application in automotive industries

Taheri, Ali 26 August 2015 (has links)
[...] Le sujet de cette thèse intervient dans le cadre du projet DEFI et vise à caractériser la notion d'Efficience Inventive en Conception afin d'élaborer des moyens de mesure de cette dernière. L’objectif étant à terme d’aboutir à l'adoption d’indicateurs aidant les entreprises à situer leurs capacités inventives en R&D. Par la suite, les entreprises ayant adopté ces indicateurs pourront, le cas échéant, entamer des actions d'évolution de leurs pratiques afin que la valeur de ces indicateurs évolue dans le sens recherché. Aux vues de la diversité des typologies d’entreprises et l’ampleur d’un tel sujet, notre recherche est focalisée sur les projets de conception de produits au sein des départements R&D de l’industrie automobile. Afin de mener cette recherche et définir les indicateurs de l’efficience inventive, nous avons étudié dans un premier temps les critères inhérents à la conception inventive. Selon nos travaux, la mesure de la performance inventive est corrélée à l’efficience inventive et doit considérer son efficacité par des caractéristiques ciblées, l’étude des connaissances impliquées et des ressources consommées. Notre mesure de l’efficience inventive est aussi basée sur l’analyse des flux des connaissances en jeu tout au long du processus d’innovation technologique, et particulièrement dans la phase de pré-développement. Elle analyse la relation entre ce qui est reçu et ce qui est appliqué ou consommé par rapport à l’inventivité. La mesure de l’inventivité est alors basée sur l’évaluation de l’idéalité, la nouveauté et l’utilité de ce qui sort du processus de conception de produit. L’ensemble des méthodes d’évaluation développées dans ce travail pour chaque critère d’inventivité, et l’efficience inventive, sont intégrés dans un système d’évaluation concret nommé IDPMS (Inventive Design Performance Measurement System) destiné à aider les directeurs des projets de la conception de produit et R&D à observer la performance inventive des équipes projet, et tenter d’améliorer les activités inventives. Donc, ce travail se catégorise dans le domain des sciences de l’ingénieur. Depuis plus de deux décennies, notre laboratoire (le LGéCo) travaille à la construction, d’abord théorique, puis déclinée en méthodes et outils, de nouvelles approches destinées à accompagner les mutations industrielles de l’ère de la qualité vers l’ère de l’innovation. A cet égard, cette thèse fournira un chaînon manquant : celui qui concerne l’évaluation, et la mesure de ce qui caractérise l’amont de l'innovation afin d’aider les entreprises à entrer, par rapport à ces dernières, en logique de performance. / [...] This thesis was defined in the DEFI project to characterize the notion of efficiency in Inventive Design, and develop the metrics of inventive-design. The objective of this proposal is to define inventive performance indicators to enhance the creative capacity in the automotive industry. The research is focused on the NPD projects of R&D department, which are known as the responsible of technological evolutions. In this respect, the main elements of design performance, and the main criteria of inventiveness are studied and merged together. The inventive performance of a R&D team is concerned with the efficiency of their activities to create inventive designs when they apply existing knowledge, and/or use creative resources. This analyzes the relationship between what is received and what is applied or consumed to achieve higher inventiveness degree. The measures of inventiveness are based on the evaluation of novelty, resourcefulness, and usefulness of what comes out from design activities. All the evaluation methods developed in this work are integrated into a concrete system as IDPMS (Inventive Design Performance Measurement System), and an initial version of the IDPMS application is developed, by which R&D and project managers can observe the inventive performance of their NPD projects. So this work is categorized in Engineering Science for specifying performance indicators of inventive design activities. In recent years, our laboratory (LGeCo) focused on developing theoretical methods, then appropriate tools to accompany the industrial changes from the era of quality to the era of innovation. In this regard, this thesis provides the missing link of this effort by evaluating the main characteristics of inventions in engineering level to help companies enter into a logic performance along their innovation projects.
20

Návrh letadlové energetické jednotky / Design of aircraft power unit

Poledno, Martin January 2010 (has links)
This diploma thesis deals with basic design and calculation of an aircraft power unit (APU). For desired shaft power the thermal cycle is calculated. Basic dimensions of compressor, turbine and exhaust system are calculated as well as thermodynamic parameters of air and hot gases along the motor. Corresponding compressor map, turbine map and characteristics of the exhaust system are designed. Based on these characteristics, an effective shaft power is being calculated in various off-design conditions. Dependency of the shaft power vs. altitude is also presented. All the calculations are made in MATLAB. Finally, simplified motor cross-section is created.

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