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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.
91

Simulação computacional : um estudo de caso em uma empresa fabricante de câmaras de ar pneumáticas

Boeira, Leandro do Amaral January 2008 (has links)
Atualmente o gerenciamento empresarial necessita de uma otimização nos recursos disponibilizados em busca de melhorias na produtividade e qualidade de produtos ou serviços, podendo tornar-se um diferencial para manter clientes. A simulação computacional pode contribuir com esta otimização, permitindo testar alterações para diferentes cenários propostos. Também pode auxiliar na compreensão das contribuições que estas alterações provocam nos processos existentes, para que se tenha um maior conhecimento de como os sistemas funcionam. Outra característica da simulação computacional é prever o comportamento futuro de sistemas, auxiliando no processo de tomada de decisão. O objetivo principal desta dissertação é a análise e avaliação da introdução da simulação computacional em uma empresa que fabrica câmaras pneumáticas de motocicletas, onde foi desenvolvido um estudo de caso. Para atingir este objetivo foram definidos os seguintes passos: identificação dos procedimentos recomendados pela literatura para estudos de simulação; execução destes procedimentos e análise do processo de implantação utilizado. Inicialmente o estudo de caso consistiu de reuniões com os gerentes para uma apresentação primária do estudo e definição do processo que poderia ser simulado. Então, foram executados os passos do método considerado e feita a análise do contato inicial da empresa com a ferramenta de simulação. Após, houve uma análise do aprendizado adquirido no processo de implantação. Finalmente, concluiu-se que o uso eficiente da técnica depende do envolvimento das pessoas conhecedoras e usuárias do processo simulado, também percebeu-se a necessidade de promover estudos futuros que aprofundem a investigação dos aspectos comportamentais envolvidos na introdução de uma nova ferramenta no ambiente fabril. / Currently, enterprise management requires an optimization of available resources aiming improvements in productivity and quality of products or services, becoming a differential for the customers. Computational simulation can contribute for such optimization, allowing testing changes for different scenarios proposed. Also it can help to understand their contributions in existing processes, to know better how systems operates. Another issue of computational simulation is predict the future behavior of systems, collaborating in the decision making process. The main goal of this dissertation is to analyze and evaluate the introduction of computational simulation in a company that produces rubber inner tubes. To reach this objective, the following steps were defined: identification of the literature recommended procedures in simulation studies; execution of these procedures; the analysis of the implantation process practiced. It was developed a case study in the rubber inner tubes company. The case study consisted initially in meetings with managers for an initial presentation of the study and definition of processes that could be simulated. Then, it was perform the steps of considered method and analysis of the first contact of the company with the simulation tool. Thus, there was learning about these deployment processes. Finally this dissertation concluded that the efficient use of the technique depends on the involvement of experts and users of the simulated process. This work raised need to promote further studies to deepen research on behavioral aspects involved in a introduction of a new tool in manufacturing environment.
92

The roles of N-Myc and L-Myc during inner ear neurosensory development

Kopecky, Benjamin Joseph 01 December 2013 (has links)
Introduction: Hearing loss affects over 500 million people worldwide and results from irreversible damage to inner ear hair cells. The only available treatment is cochlear implants, which may be unable to provide sensory input if neuronal connections are lost, as they are in mouse models. Thus, regeneration of hair cells offers the only permanent cure; however, such therapeutic intervention requires a detailed molecular understanding inner ear development and hair cell maintenance. During mouse development, there is a balance between proliferation and differentiation that not only determines the size of the ear, but also is needed to form a functional sensory unit. The fulcrum to this balance is N-Myc, a key transcription factor that acts as a node incorporating many upstream growth signaling pathways and funnels them to directly alter the cell cycle and at the same time inhibits differentiation. The loss of N-Myc results in major morphogenetic abnormalities, including a progressive loss of cochlear, despite their initial formation. Interestingly, N-Myc is present in inner ear hair cells after birth, long after proliferation in the inner ear ceased. In addition to N-Myc, L-Myc is co-expressed throughout development in the inner ear. This data suggests that N-Myc and L-Myc may play partially redundant roles both early during development and later in hair cells. Elucidating the relative importance of the Mycs and their interdependent roles in maintaining the balance between proliferation and differentiation may shed light on future hair cell regeneration avenues. Methods: We generated two Cre-LoxP lines, knocking out both N-Myc and L-Myc before (Pax2-Cre) and after (Atoh1-Cre) hair cell formation. We assessed the possibility of Myc redundancy through 3D reconstructions generated from confocal image stacks from E10.5-E18.5 and the effects of early Myc loss on the balance between proliferation and differentiation through a quantitative PCR study that assessed relative changes in gene expression, using the Pax2-Cre N-Myc f/f L-Myc f/f mice. We assessed organ of Corti development and functionality at P21 and four months of age in the Atoh1-Cre N-Myc f/f L-Myc f/f mice. Results: The development of the Pax2-Cre N-Myc f/f L-Myc f/f mutant ear was more severely impacted than the Pax2-Cre N-Myc f/f alone, as shown by an additional 50% reduction in size. Genes important to cell cycle maintenance were downregulated whereas differentiation transcription factors were initially downregulated but subsequently later upregulated to normal levels. In Atoh1-Cre N-Myc f/f L-Myc f/f mice, there were no defects in hair cell development. Discussion: There appears to be redundancy between N-Myc and L-Myc with N-Myc playing a more important role in inner ear formation. The late-onset defects seen in the Pax2-Cre N-Myc f/f mice appear to be a result of abnormal formation of hair cells due to the disruption in the balance between proliferation and differentiation much earlier on. This is the first time such a late-onset hair cell loss has been shown to be due to a defect sustained much earlier and is an important finding as the majority of people suffer from late-onset hearing loss. Additionally, these findings highlight the continued therapeutic importance in elucidating the molecular interactions controlling the delicate shift from a proliferating precursor to a differentiating cell.
93

Cosmic shopping

Flanagan, Josephine M., University of Western Sydney, Nepean, School of Contemporary Arts January 2000 (has links)
This novel is about Jess, a left wing trade unionist and student lawyer who, caught up in a fast-paced Sydney inner city life, goes to a hypnotist in an effort to drink less and instead has an experience of God. Her conscious self cannot cope with this and she represses it, but it still exists in a deeper part of her and the novel tracks the path by which she finally hauls and hacks her way back to it. The novel is divided into four parts, David, Jane, Padma and Jess. The first three parts tell of her emotionally dependencies on other people, and in the last section she finally finds a kind of hard-won peace and self-acceptance, and a love of God that is rooted in the small joys of her daily life. / Master of Arts (Hons) (Creative Writing)
94

台灣地區工資結構與工資差異之實証研究

翁郁玲 Unknown Date (has links)
本文以勞動市場基本供需架構,利用行政院主計處人力運用調查資料,探討台灣地區工資結構與工資差異之變化。由基本資料分析發現,不同教育程度間的工資差異持續縮小,而此極現象主要來自供給面與需求面的變動。 在實証上,採用內積(inner product)法、分解(decomposition)法、及特徵根與特徵向量(eigenvalue and eigenvector)法分析發現,供給面之變勁主要是由於教育普及,人人追求高學歷,導致低教育程度者供給減少,高教育程度者供給增加,而此極變動是造成國中、高中程度中工作經驗屬於兩端者與高職、專科、大學程度中工作經驗屬於中間者工資差異縮小的主要因素:前者供給減少故工資上升,後竹供給增加故工資下降,所以工資差異縮小。另外,國中、高中程度中工作經驗屬於中間者與商職、專科、大學程度中工作經驗屬於兩端者工資差異縮小的主要因素,則為需求面之變動所致,而本文採用之需求變數為製造業多因素生產力指數,也因此發現台灣製造業的技術進步是屬於偏非技術性的技術進步,有利於低教育程度者,而不利於高教育程度者,故此項需求面因素縮小了高低教育程度間的工資差異。
95

Impact of Assimilating Airborne Doppler Radar Winds on the Inner-Core Structure and Intensity of Hurricane Ike (2008)

Gordon, Ronald Walter 26 July 2011 (has links)
Accurate prediction of Tropical Cyclones (TC) is vital for the protection of life and property in areas that are prone to their destructive forces. While significant improvements have been made in forecasting TC track, intensity remains a challenge. It is hypothesized that accurate TC intensity forecast requires, among other things, an adequate initial description of their inner-core region. Therefore, there must be reliable observations of the inner-core area of the TC and effective data assimilation (DA) methods to ingest these data into the Numerical Weather Prediction (NWP) models. However, these requirements are seldom met at the relatively low resolution of operational global prediction models and the lack of routine observations assimilated in the TC inner-core. This study tests the impacts of assimilating inner-core Airborne Doppler Radar (ADR) winds on the initial structure and subsequent intensity forecast of Hurricane Ike (2008). The 4-dimensional variational (4DVar) and the 3-dimensional variational (3DVar) methods are used to perform DA while the Weather Research and Forecasting (WRF) model is used to perform forecasts. It is found that assimilating data helps to initialize a more realistic inner-core structure using both DA methods. Additionally, the resulting short-term and long-term intensity forecasts are more accurate when data is assimilated versus cases when there is no DA. Additionally, it is found that in some cases the impact of DA lasts up to 12 hours longer with 4DVar versus 3DVar. It is shown that this is because the flow-dependent 4DVar method produces more dynamically and balanced analysis increments compared to the static and isotropic increments of 3DVar. However, the impact of using both methods is minimal in the long-range. The analyses show that at longer forecast range the dynamics of hurricane Ike was influenced more by outer environment features than the inner-core winds.
96

Structural and metamorphic evolution of the west-central Newton window, eastern Inner Piedmont, Burke, Catawba, and Lincoln Counties, North Carolina

Gilliam, William George 01 August 2010 (has links)
Rocks of the western and eastern Inner Piedmont, along with the eastern Blue Ridge, comprise the Neoacadian metamorphic core of the southern Appalachians. The composite Inner Piedmont consists of the eastern Tugaloo (western Inner Piedmont) and Cat Square (eastern Inner Piedmont) terranes, which are separated by the Brindle Creek fault. Geochronologic evidence established the Brindle Creek fault as a terrane boundary within the Inner Piedmont, separating terranes of Laurentian and mixed Laurentian/Avalonian (peri-Gondwanan) zircon suites. The Newton window exposes Tugaloo terrane rocks of the Tallulah Falls Formation in the footwall of the Brindle Creek thrust sheet. Detailed geologic mapping in the western Newton window revealed structural and metamorphic similarities between rocks across the Brindle Creek fault. Peak metamorphism occurred contemporaneously with peak deformation, reaching upper amphibolite facies across both terranes. Peak Neoacadian metamorphism occurred between 360 and 345 Ma. Electron microprobe analyses of Cat Square terrane core and rim garnet-biotite and garnet-plagioclase pairs indicate an average temperature and pressure of 620 C, 3.6 kbar and 710 C, 6.1 kbar, respectively. Temperature and pressure estimates from the lower Tallulah Falls Formation core and rim analyses yield conditions of 570 C, 4.1 kbar and 690 C, 5.9 kbar, respectively. The maximum burial depth for both Cat Square and Tugaloo terrane rocks is ~20 km. The range in metamorphic ages suggests subduction and accretion occurred at a rate of 1 kilometer per 1.75 million years. Six deformational events shaped the western Newton window. D1 features are limited to amphibolite boudins of the Tugaloo terrane. D2 regional penetrative structures such as high-temperature foliations, mineral stretching lineations, and curved fold axes are the product of Neoacadian tectonism. The dominant S2 foliation trends north-northwest and dips moderately to the west-southwest. North-northwest-trending L2 mineral lineations parallel F2 fold axes, creating a curved map pattern recording crustal flow in an ancient orogenic channel. D3 resulted in open folding. The D4 event produced regional open folds. D5 and D6 features occur as joints, cataclasis, and diabase intrusion.
97

Transforming the existing transportation interchange / labour market /

Veldsman, Dewald. January 2006 (has links)
Thesis (M.Arch)(Prof.)--University of Pretoria, 2006. / Includes bibliographical references. Available on the Internet via the World Wide Web.
98

Molecular analysis of placodal development in zebrafish

Phillips, Bryan T. 12 April 2006 (has links)
Vertebrates have evolved a unique way to sense their environment: placodallyderived sense organs. These sensory structures emerge from a crescent-shaped domain, the preplacodal domain, which surrounds the anterior neural plate and generates the paired sense organs as well as the cranial ganglia. For decades, embryologists have attempted to determine the tissue interactions required for induction of various placodal tissues. More recently, technological advances have allowed investigators to ask probing questions about the molecular nature of placodal development. In this dissertation I largely focus on development of the otic placode. I utilize loss-of-function techniques available in the zebrafish model system to demonstrate that two members of the fibroblast growth factors family of secreted ligands, Fgf3 and Fgf8, are redundantly required for otic placode induction. I go on to show that these factors are expressed in periotic tissues from the beginning of gastrulation. These findings are consistent with a model where Fgf3 and Fgf8 signal to preotic tissue to induce otic-specific gene expression. This model does not address other potential inducers in otic induction. A study using chick explant cultures suggests that a member of the Wnt family of secreted ligands also has a role in otic induction. I therefore test the relative roles of Wnt and Fgf in otic placode induction. The results demonstrate that Wnt functions primarily to correctly position the Fgf expression domain and that it is these Fgf factors which are directly received by future otic cells. Lastly, I examine the function of the muscle segment homeobox (msx) gene family expressed in the preplacodal domain. This study demonstrates that Msx proteins refine the boundary between the preplacodal domain and the neural plate. Further, msx genes function in the differentiation and survival of posterior placodal tissues (including the otic field), neural crest and dorsal neural cell types. Loss of Msx function results in precocious cell death and morphogenesis defects which may reflect perturbed BMP signaling.
99

Toeplitz operators and division theorems in anisotropic spaces of holomorphic functions in the polydisc

Harutyunyan, Anahit V. January 2001 (has links)
This work is an introduction to anisotropic spaces, which have an ω-weight of analytic functions and are generalizations of Lipshitz classes in the polydisc. We prove that these classes form an algebra and are invariant with respect to monomial multiplication. These operators are bounded in these (Lipshitz and Djrbashian) spaces. As an application, we show a theorem about the division by good-inner functions in the mentioned classes is proved.
100

Polymer hydrogel/polybutadiene/iron oxide nanoparticle hybrid actuators for the characterization of NiTi implants

Jeličić, Aleksandra, Friedrich, Alwin, Jeremić, Katarina, Siekmeyer, Gerd, Taubert, Andreas January 2009 (has links)
One of the main issues with the use of nickel titanium alloy (NiTi) implants in cardiovascular implants (stents) is that these devices must be of very high quality in order to avoid subsequent operations due to failing stents. For small stents with diameters below ca. 2 mm, however, stent characterization is not straightforward. One of the main problems is that there are virtually no methods to characterize the interior of the NiTi tubes used for fabrication of these tiny stents. The current paper reports on a robust hybrid actuator for the characterization of NiTi tubes prior to stent fabrication. The method is based on a polymer/hydrogel/magnetic nanoparticle hybrid material and allows for the determination of the inner diameter at virtually all places in the raw NiTi tubes. Knowledge of the inner structure of the raw NiTi tubes is crucial to avoid regions that are not hollow or regions that are likely to fail due to defects inside the raw tube. The actuator enables close contact of a magnetic polymer film with the inner NiTi tube surface. The magnetic signal can be detected from outside and be used for a direct mapping of the tube interior. As a result, it is possible to detect critical regions prior to expensive and slow stent fabrication processes.

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