11 |
Development of a MR Hydraulic Bushing for Automotive ApplicationsSchubert, Brad January 2005 (has links)
The purpose of this work is to design a semi-active magnetorheological (MR) hydraulic bushing. The semi-active bushing is intended to be used to isolate a cylinder deactivating engine. Cylinder deactivation causes high transient torsional loading in addition to changing the magnitude and mode of engine vibrations requiring an adaptive or controllable isolator. <br /><br /> Practical and simple semi-active control strategies are inspired by investigating the optimization of linear and slightly cubic nonlinear single degree of freedom isolators. Experimental verification of the optimization technique, which minimizes the root mean square (RMS) of engine acceleration frequency response and RMS of the force transmitted frequency response, shows that this method can be implemented on real linear systems to isolate the engine from harmonic inputs. This optimization technique is also applied to tune selected model parameters of existing two degree of freedom hydraulic bushings. <br /><br /> This thesis also details the development of a MR hydraulic bushing. The MR bushing design retrofits an existing bushing with a pressure driven flow mode valve on the inertia track. A new efficient valve design is selected and developed for the application. The MR hydraulic bushing is designed, mathematically modeled, and numerically simulated. The simulation results show that the MR bushing tends to increase the low frequency dynamic stiffness magnitude while simultaneously decreasing the phase. The next stage of the project is fabrication and testing of the semi-active bushing. The performance of the manufactured MR bushing is tested on a base excitation apparatus. Varying the current input to the MR valve was found to have a small effect on the response of the suspended mass. The results are in agreement with the effects demonstrated by the dynamic stiffness numerical simulation.
|
12 |
High frequency continuous-time circuits and built-in-self-test using CMOS RMS detectorVenkatasubramanian, Radhika 25 April 2007 (has links)
The expanding wireless market has resulted in complex integrated transceivers
that involve RF, analog and mixed-signal circuits, resulting in expensive and complicated
testing. The most important challenges that test engineering faces today are (1) providing
a fast and accurate fault-diagnosis and performance characterization so as to accelerate
the time-to-market and (2) providing an inexpensive test strategy that can be integrated
with the design so as to aid the high-volume manufacturing process. The first part of the
research focuses on the design of an RMS detector for built-in-self-test (BIST) of an RF
integrated transceiver that can directly provide information at various test points in the
design. A cascode low noise amplifier (LNA) has been chosen as the device under test
(DUT). A compact (< 0.031 mm2) RF RMS detector with negligible input capacitance (<
13 fF) has been implemented in 0.35 õm CMOS technology along with the DUT.
Experimental results are currently being assimilated and compared with the simulation
results. Frequency limitations were encountered during the testing process due to
unexpected increase in the value of the N-well resistors. All other problems faced during
the testing, as well as the results obtained so far, are presented in this thesis. In the second part of the research, the use of the RMS detector for BIST has been
extended to a continuous-time high-frequency boost-filter. The proposed HF RMS
detector has been implemented along with a 24 dB 350 MHz boost filter as the DUT on
0.35 õm CMOS technology. The HF RMS detector occupies 0.07 mm2 and has an input
capacitance of 7 fF. The HF RMS detector has a dynamic range greater than 24 dB
starting from -38 dBm of input power. The bandwidth and boost of the filter have been
accurately estimated in simulation using the HF RMS detector. The sensitivity of an
intermediate band pass node of the filter has also been monitored to predict the filter's
sensitivity to Q errors.
The final part of the research describes the design of a single-ended to differential
converter for use in a broadband transceiver operating from 50-850 MHz. This circuit is
used as the second stage in the transceiver after the LNA. The design has been simulated
on a 0.35 um CMOS process and has a power consumption of 13.5 mW and less than 8
dB of noise figure over the entire band. It is capable of driving a 500fF load with less
than 1dB of gain ripple over the entire band (50-850 MHz).
|
13 |
A design strategy for reconfigurable manufacturing systems (RMSs) using the analytical hierarchical process (AHP): A case study.Abdi, M. Reza, Labib, A.W. January 2003 (has links)
No / This paper presents Reconfigurable Manufacturing System (RMS) characteristics through comparison with conventional manufacturing systems in order to address a design strategy towards a RMS. The strategy is considered as apart of a RMS design loop to achieve a reconfigurable strategy over its implementation period. As another part of the design loop, a reconfiguration link between market and manufacturing is presented in order to group products into families (reconfiguring products) and then assign them to the required manufacturing processes over configuration stages. In particular, the Analytical Hierarchical Process (AHP) is employed for structuring the decision making process for the selection of a manufacturing system among feasible alternatives based on the RMS study. Manufacturing responsiveness is considered as the ability of using existing resources to reflect new environmental and technological changes quickly. The AHP model highlights manufacturing responsiveness as a new economic objective along with classical objectives such as low cost and high quality. The forward-backward process is then proposed to direct and control the design strategy under uncertain conditions during its implementation period. The proposed hierarchy is generic in structure and could be applicable to many firms by means of restructuring the criteria. This work is based on a case study in a manufacturing environment. Expert Choice software (Expert Choice 1999) is applied to examine the structure of the proposed model and achieve synthesise/ graphical results considering inconsistency ratios. The results are examined by monitoring sensitivity analysis while changing the criteria priorities. Finally, to allocate available resources to the alternative solutions, a (0-1) knapsack formulation algorithm is represented.
|
14 |
Improved Heuristics for Partitioned Multiprocessor Scheduling Based on Rate-Monotonic Small-TasksMüller, Dirk, Werner, Matthias 01 November 2012 (has links)
Partitioned preemptive EDF scheduling is very similar to bin packing, but there is a subtle difference. Estimating the probability of schedulability under a given total utilization has been studied empirically before. Here, we show an approach for closed-form formulae for the problem, starting with n = 3 tasks on m = 2 processors.
|
15 |
Prozessmodellierung von Reaktiv-Multischicht-Systemen (RMS)Rühl, Maximilian 02 September 2015 (has links)
The focus of this work is the theoretical and experimentell descreption of so-called Reactive Multilayer Systems (RMS). The RMS consist of at least two mostly metallic materials, which can exothermic response with each other. Using magnetron sputter deposition (MSD) several hundred to thousands alternating layers are produced. The periodic thickness varies between 10-150 nm and the total thickness between 10-100 µ m . The exotermic reaction is effected by an activation energy, e.g. with an electric spark. In this case a phase transition of the RMS materials, which are in a metastable equilibrium, will take place. This released energy in the shape of heat, which actvates the reaction in the neighboring areas. It forms a self-sustaining thermal wave through the RMS foil. In this case the amount of energy is present, that a solder on the RMS or the joining samples or even the material itself can be melted. Therefore the RMS can be used as a heat source for joining two components. The major advantage of this technology is the very low heat input in the bonding components, due to the milliseconds of the reaction. Thus the components are heated only superfical and there is no structural damage. Thus a very low-stress joining is possible.
Furthermore is guaranteed, because of the metallic materials, a very high electrical and thermal conductivity. For the theoretical characterization of the physical and chemical processes within the RMS FEM-Simulations of the absolut temperature and the propagation velocity are preformed. In order to calculate the tmeperature ditribution in the components a new method will presented. It is thus possible to calculate the temperature penetration of the components to determine potential thermal barrier layer-thickness and the meltig time. Thus parameters for the specific joint problem such as period thickness, etc. of the RMS are derived. Modelling the heat transport after joining with RMS it is possible to derive a corralation between the thermal conductivity and shear strength. To quantify the theoretical results and to require certain parameters for the calculations experiments were preformed. The RMS will be investigated experimentally in terms of their enthalpy H , propagation velocity v , nascent temperature, melting time t schmelz , interdiffusion zone w , phase transition and its use as inovative heat source for joining components. The experimental results are compared with the theortical and complet this work.
|
16 |
Thin films with high surface roughness: thickness and dielectric function analysis using spectroscopic ellipsometryLehmann, Daniel, Seidel, Falko, Zahn, Dietrich R.T. 06 March 2014 (has links) (PDF)
An optical surface roughness model is presented, which allows a reliable determination of the dielectric function of thin films with high surface roughnesses of more than 10 nm peak to valley distance by means of spectroscopic ellipsometry. Starting from histogram evaluation of atomic force microscopy (AFM) topography measurements a specific roughness layer (RL) model was developed for an organic thin film grown in vacuum which is well suited as an example. Theoretical description based on counting statistics allows generalizing the RL model developed to be used for all non-conducting materials. Finally, a direct input of root mean square (RMS) values found by AFM measurements into the proposed model is presented, which is important for complex ellipsometric evaluation models where a reduction of the amount of unknown parameters can be crucial. Exemplarily, the evaluation of a N,N’-dimethoxyethyl-3,4,9,10-perylene-tetracarboxylic-diimide (DiMethoxyethyl-PTCDI) film is presented, which exhibits a very high surface roughness, i.e. showing no homogeneous film at all.
|
17 |
A evolução da dimensão social da integração regional: o caso das normas do Mercosul-Saúde / The evolution of regional integration\'s social dimension: the case of Mercosur-health normsSato, Nathalie Suemi Tiba 25 July 2014 (has links)
O trabalho, composto por dois artigos, tem como tema a dimensão social da integração regional, caracterizada pela relação entre direitos sociais e interesses comerciais, com foco no caso do Mercosul. O primeiro artigo realiza uma revisão bibliográfica, sistematizando-a em duas grandes linhas de estudo. Primeiramente, a relação entre comércio e direitos humanos, em particular o direito à saúde, e o potencial da integração regional para a sua efetivação. Em segundo lugar, as interpretações sobre a evolução institucional e conceitual da dimensão social do Mercosul. O segundo artigo apresenta os resultados do estudo empírico do caso das normas do Mercosul-Saúde, orientado pela hipótese de que, em consonância com uma suposta mudança de paradigma, as normas sanitárias teriam migrado da eliminação de barreiras ao livre comércio para a proposição de políticas integradas tendentes a dar efetividade ao direito à saúde dos cidadãos mercosulinos. / This work, consisting of two articles, has as its main theme the social dimension of regional integration, characterized by the relationship between social rights and commercial interests, focusing on the case of Mercosur. The first article conducts a review of the literature, systematizing two main lines of study. Firstly, the relationship between trade and human rights, especially the right to health, and the potential of regional integration for its effectiveness. Secondly, the interpretations of the institutional and conceptual evolution of the social dimension of Mercosur. The second article presents the results of a empirical study of Mercosur\'s health standards, based on the hypothesis that, in line with a supposed paradigm shift, they have migrated from the elimination of barriers to liberalize trade to the proposition of integrated policies to give effectiveness to the right to health of Mercosur\'s citizens.
|
18 |
Développement d’une nouvelle famille d’indicateurs de performance pour la conception d’un système manufacturier reconfigurable (RMS) : approches évolutionnaires multicritères / Development of a new family of performance indicators for the design of a reconfigurable manufacturing system (RMS) : multi-criteria evolutionary approachesHaddou Benderbal, Hichem 20 June 2018 (has links)
L'environnement manufacturier moderne est face à un bouleversement de paradigmes nécessitant plus de changeabilité au niveau physique et logique. Un système manufacturier Changeable est défini comme un système de production ayant les capacités de faciliter les changements adéquats, permettant d'ajuster ses structures et ses processus en réponse aux différents besoins. Dans ce contexte, les systèmes manufacturiers doivent se doter d’un très haut niveau de reconfigurabilité, qui est considérée comme l’un des facteurs majeurs du concept de changeabilité. En effet, dans la vision de l'Usine du Futur, la reconfigurabilité est essentielle pour s'adapter efficacement à la complexité croissante des environnements manufacturiers. Elle assure une adaptation rapide, efficace et facile de ces systèmes tout en étant réactif, robuste et économiquement compétitif. L’objectif est de répondre aux nouvelles contraintes internes et externes telles que la globalisation, la variété des produits, la personnalisation de masse ou le raccourcissement des délais. À travers cette thèse, nous étudions la problématique de conception des systèmes manufacturiers reconfigurables (Reconfigurable Manufacturing System – RMS). L’objectif consiste à concevoir des systèmes réactifs en se basant sur leurs capacités en matière de reconfigurabilité. Nous avons étudié ce problème sur trois niveaux : (i) le niveau des composantes, relatif aux modules des machines reconfigurables, (ii) le niveau des machines et leurs interactions, ainsi que l’impact de ces interactions sur le système et (iii) le niveau de l'atelier, composé de l'ensemble des machines reconfigurables. Nous avons développé pour chaque niveau, des indicateurs de performance afin d’assurer les meilleures performances du système conçu, tels que l’indicateur de modularité, l’indicateur de flexibilité, l’indicateur de robustesse et l’effort d'évolution d'un système reconfigurable. Pour l'ensemble des problèmes étudiés, nous avons développé des modèles d’optimisation multicritère, résolus à travers des heuristiques ou des métaheuristiques multicritères (comme le recuit simulé multicritère (AMOSA) et les algorithmes génétiques multicritère (NSGA-II)). De nombreuses expériences numériques et analyses ont été réalisées afin de démontrer l’applicabilité de nos approches / The modern manufacturing environment is facing a paradigm shift that require more changeability at physical and logical levels. A Changeable Manufacturing System is defined as a production system that has the ability to facilitate the right changes, allowing the adjustment of its structures and processes in response to the different needs. In this context, manufacturing systems must have a very high level of reconfigurability, which is considered to be one of the major enablers of changeability. From the perspective of the “Factory of the future”, the reconfigurability is essential to effectively adapt to the ever-increasing complexity of manufacturing environments. It allows a rapid, efficient and easy adaptation of these systems while being responsive, robust and economically competitive. The objective is to respond to new internal and external constraints in terms of globalization, variety of products, mass customization, and shorter lead times. Through this thesis, we study the problem of design of reconfigurable manufacturing systems (RMS) that meets these requirements. The goal is to design responsive systems based on their key features of reconfigurability. We have studied the RMS design problem on three levels: (i) the level of the components, relating to the modules of the reconfigurable machines, (ii) the machine level and their interactions, as well as the impact of these interactions on the system and (iii) the workshop level composed of all the reconfigurable machines. We have developed for each level, performance indicators to ensure a better responsiveness and a high performance of the designed system, like the modularity index, the flexibility index, the robustness index and the layout evolution effort of a reconfigurable system. For each of the studied problems, we developed multicriteria optimization models, solved through heuristics or multicriteria metaheuristics (such as archived multi-objective simulated annealing (AMOSA) and multi-objective genetic algorithms (NSGA-II)). Numerous numerical experiments and analyzes have been performed to demonstrate the applicability of our approaches
|
19 |
Étude de la régulation post-transcriptionnelle de l’expression des gènes par la protéine de liaison à l’ARN IMP-2 au cours de la myogenèse / Post-transcriptional regulation of gene expression by IMP-2 during myogenesis.Boudoukha, Selim 25 November 2011 (has links)
Les rhabdomyosarcomes embryonnaires et aléolaires (RMS) appartiennent aux tumeurs des tissus mous les plus fréquentes chez les enfants dont elles représentent 2/3 des cas. Plusieurs données suggèrent que la dérégulation des cellules progénitrices du muscle squelettique pourrait jouer un rôle dans l'émergence des cellules de RMS qui ont aussi bien perdu le contrôle de la régulation de la prolifération cellulaire que la capacité à se différencier.Néanmoins les mécanismes de développement des RMS restent à caractériser. La famille des IMPs et notamment IMP-2, protéines liant les ARN, sont à la fois fortement exprimées dans le muscle en régénération in vivo mais aussi dans les cellules de RMS.Au cours de ma thèse, j’ai pu mettre en évidence le rôle d’IMP-2 dans la motilité des cellules de RMS et dans les cellules musculaires ainsi que dans le contrôle de l’intégrité du cytosquelette de microtubules (MTs) et dans le remodelage des adhésions focales. En effet, IMP-2 est impliqué à la fois dans la régulation de l’expression de MuRF-3, une protéine lié àla stabilisation des MTs et de Pinch-2, un important médiateur de l’adhésion cellulaire. / The RNA-binding proteins IMPs (IGF-II mRNA binding protein) first discovered in rhabdomyosarcoma cells (RMS) are expressed during embryonic development but their expression is decreased in adult tissues.We showed that IMPs and particularly IMP-2 are strongly expressed in mouse myoblatsts, during early regeneration of skeletal muscle in vivo and in and RMS. IMP-2 loss of function experiments using siRNA have shown that IMP-2 is necessary for microtubules stability(MTs), cell motility and invasion of myoblasts and RMS.Expression of IMP-2 specifically increases MTs stability by an enrichment of detyrosinated tubulin Glu-tubulin. Detyrosination is indispensable for myogenic differentiation and plays substantial role in tumor growth. Additionaly, MTs stabilization play an important role in focal adhesion remodeling, in cytoskeleton integrity, cell adhesion and cell motility.To get new insight into molecular mechanism underlying the function of IMP-2 in MTs stability and cell motility, full ranscriptome analysis was performed between IMP-2 knockdown (KD) myoblasts and control myoblatsts. We have further shown that IMP-2 controls the mRNA levels of many important mediators of cell adhesion such as PINCH-2, as well as multiple cytoskeleton remodeling, such as MuRF-3.We have identified a number of functionally relevant protein partners of IMP-2.Moreover subsequent RNAi screens have revealed the importance of IMP-2 regulated transcripts involved in cell motility and cell adhesion In conclusion, we show that IMP-2 dependent regulation of mRNA such as MuRF3 and PINCH2 largely contributes to the motility –deficient in IMP-2 KD cells. Moreover these results indicate clearly, that further analysis of IMP2 protein partners and RNA targets regulated by IMP-2 will help to characterized the function of IMP-2 and to propose a model of IMP-2 transcriptional regulation of gene expression in myoblasts and RMS cells.
|
20 |
Estudo sistemático com complexos de inclusão a base de ciclodextrinas no controle de interferentes químico-ambientais : uma metodologia teórica. / Systematic study of inclusion complexes of the base cyclodextrins in the control of interfering chemical-environmental: theoretical methodologyXavier, Maria Jose 13 October 2009 (has links)
Conselho Nacional de Desenvolvimento Científico e Tecnológico / One of the major environmental problems under discussion is related to the fact that natural and synthetic hormones have been frequently found in effluent from Wastewater Treatment Sewage (TSE) and natural waters, as well as the fact that
conventional treatments are not effective in removing these substances. These substances are one recent class of environmental contaminants that interfere with the
functioning of the human endocrine system and are related to occurrence of several types of cancer. In the attemp to solve this problem, we propose a study, from a theoretical approach, with cyclodextrins (CDs) molecules, that can be able to form inclusion complexes with many organic substances, poorly soluble in water, thus we believe that CDs are complexing agents promising for this task. In this work we studied the complexation of four steroid drugs commonly found in Wastewaters, with fourteen βCDs chosen, under different criterion to determine one CD more promising for the
removal these steroids from the environment. Initially, we propose us to identify a semiempirical method can be better in describe the crystal structure of many compounds on the inclusion of CDs. On a second step applying a study about the formation of inclusion complexes with steroids, investigating two inclusion modes: in and out. The initial calculations indicated the PM3 method as the best method in the structural
description of this type of system. Since the results of the complexation with steroids suggest that, in general, the structural orientation energetically more favorable corresponds to out arrangement. An analysis about the interactions more significant to the stability of the complex shows that the LH and the interactions dipole-dipole has a
small contribution to the stabilization of the complexes, on the other hand, the hydrophobicity of the substituents on steroids rings, has been pointed as a crucial force
to decide how s more stable the steroid enters towards the cavity of the CD. And finally, the results show that in general, all the CDs investigated, theoretically, have similar behavior among themselves. / Um dos grandes problemas ambientais em discussão está relacionado ao fato de hormônios naturais e sintéticos estarem sendo freqüentemente encontrados em efluentes de Estações de Tratamento de Esgoto (ETEs) e águas naturais, bem como o fato de os tratamentos convencionais não serem eficientes em remover tais substâncias. Estas substâncias são uma categoria recente de poluentes ambientais que interferem no funcionamento do sistema endócrino humano e de animais, estando relacionadas com o aparecimento de diversos tipos de câncer e disfunções nestes organismos vivos. Na tentativa de contribuir para resolver este problema, propomos um estudo, a partir de uma metodologia teórica, com ciclodextrinas (CDs), moléculas hábeis para formar
complexos de inclusão com muitas substâncias orgânicas pouco solúveis em meio aquoso, pois, acreditamos que as CDs são agentes complexantes promissores para tal tarefa. Assim, neste trabalho estudamos a complexação dos 4 esteróides mais comuns encontrados nas ETEs, com 14 βCDs diferentes escolhidas a critério, a fim de determinar uma CD mais promissora para a remoção destes esteróides do meio ambiente. Inicialmente, procuramos identificar um método semiempírico capaz de melhor descrever a estrutura cristalográfica de vários compostos de inclusão a base de
CDs, para numa segunda etapa aplicá-lo no estudo da formação de complexos de inclusão com os esteróides, investigando dois modos de inclusão: in e out. Os cálculos
iniciais apontaram o método PM3 como o melhor método na descrição estrutural deste tipo de sistema. Já os resultados dos estudos de complexação com os esteróides sugerem
que, no geral, o arranjo estrutural energeticamente mais favorável corresponde ao arranjo out. Uma análise das interações mais significativas para a estabilidade dos complexos mostra que, as LHs e as interações dipolo-dipolo têm uma contribuição pequena para a estabilização dos complexos, por outro lado, a hidrofobicidade dos substituintes nos esteróides, se mostrou fundamental para decidir o modo de inclusão mais favorável com que o esteróide entra na cavidade da CD. E finalmente, os resultados mostram que de modo geral, todas as CDs investigadas, teoricamente,
possuem comportamento semelhante entre si, na inclusão dos esteróides estudados.
|
Page generated in 0.0323 seconds