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Andersson, Jonsson Amadeus. "Simulations of Pre-arcing Times in Diazed Fuses by an Electrothermal Dynamic Model." Thesis, KTH, Skolan för elektroteknik och datavetenskap (EECS), 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-295599.
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The determination of the pre-arcing time of a fuse given a specific current is crucial during the selection process if the fuse is to be effective for the given application. Often the data supplied by the manufacturer is enough to determine this time, however this is not always the case. For this purpose a fuse model of a diazed fuse has been developed in order to simulate the pre-arcing times in the range of 2 ms to 2 s. The model is implemented in MATLAB and simulates the pre-arcing time for a given current together with fuse parameters such as the materials and the geometry of the fuse. The model has been tested experimentally by running specific currents designed to represent a wide variety of currents which a fuse might be subjected to. The tests were done on 10A gG fuses for which the current through the fuse was logged and then used as input to the fuse model, the simulated time and the measured time was then compared. The simulated times are in general faster than the measured pre-arcing times, this is mainly due to the rate of change of thermal conductivity of the sand with respect to temperature being approximated in conjunction with thermal radiation not being taken into consideration. More testing needs to be done to validate the model for different current ratings and fuse-element designs.Att bestämma smälttiden för en säkring som utsätts för en given ström är viktigt för att kunna avgöra om dess prestanda är tillräcklig för en viss applikation. I de flesta fall är det möjligt att använda tillverkarens data tillsammans med vågformen för att bestämma smälttiden, men det kan även inträffa att detta inte är möjligt. För dessa fall har en modell av en diazed säkring utvecklas för att simulera smälttiden inom 2 ms till 2 s. Modellen har implementerats i MATLAB och beräknar smälltiden för en given ström och parametrar för säkringen. Modellen har testats experimentellt genom att säkringar har utsatts för en mängd olika strömmar som representerar de olika strömmar som säkringen kan utsättas för. Testerna gjordes på 10 A gG säkringar där strömmen genom säkringen loggades för att sedan användas som ingångsvärde till modellen, tiderna för den uppmätta smälttiden och den beräknades smälltiden jämfördes sedan. De simulerade smälttiderna är lägre jämfört med de uppmätta, detta beror dels på att förändringen av värmeledningsförmågan med temperaturökning hos sanden är okänd och är uppskattad från referenser och dels på att värmestrålning inte har ingått i modellen. Mer tester behöver utföras för att validera modellen mot fler strömstyrkor och designer.
Kandidatexjobb i elektroteknik 2020, KTH, Stockholm
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Eatinger, Ryan Joseph. "Built-in self-test in integrated circuits - ESD event mitigation and detection." Thesis, Kansas State University, 2011. http://hdl.handle.net/2097/13538.
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Master of ScienceDepartment of Electrical Engineering
William Kuhn
When enough charges accumulate on two objects, the air dielectric between them breaks down to create a phenomenon known as electrostatic discharge (ESD). ESD is of great concern in the integrated circuit industry because of the damage it can cause to ICs. The problem will only become worse as process components become smaller. The three main types of ESD experienced by an IC are the human body model (HBM), the charged device model (CDM), and the machine model (MM). HBM ESD has the highest voltage while CDM ESD has the highest bandwidth and current of the three ESD types. Integrated circuits generally include ESD protection circuitry connected to their pads. Pads are the connection between the IC and the outside world, making them the required location for circuitry designed to route ESD events away from the IC's internal circuitry. The most basic protection pads use diodes connected from I/O to VDD and I/O to ground. A voltage clamp between VDD and ground is also necessary to protect against CDM and MM event types where the device may not yet have a low impedance supply path connected. The purpose of this research is to investigate the performance of ESD circuits and to develop a method for detecting the occurrence of an ESD event in an integrated circuit by utilizing IC fuses. The combination of IC fuses and detection circuitry designed to sense a broken fuse allows the IC to perform a built-in self-test (BIST) for ESD to identify compromised ICs, preventing manufacturers from shipping damaged circuits. Simulations are used to design an optimized protection circuit to complement the proposed ESD detection circuit. Optimization of an ESD pad circuit increases the turn-on speed of its voltage clamps and decreases the series resistance of its protection diodes. These improvements minimize the stress voltage placed on internal circuitry due to an ESD event. An ESD measurement setup is established and used to verify voltage clamp operation. This research also proposes an ESD detection circuit based on IC fuses, which fail during an ESD event. A variety of IC fuses are tested using the ESD measurement setup as well as a TLP setup in order to determine the time and current needed for them to break. Suitable IC fuses have a resistance less than 5 Ω and consistently break during the first trial.
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Freitas, Kenedy Antônio de. "Estudo experimental do modelo aleatório de fusíveis." Universidade Federal de Viçosa, 2007. http://locus.ufv.br/handle/123456789/4279.
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The objective of this work is to verify through an experimental research of the Randorn Fuse Model, how the orientation and disorder of the fuse network influence the process of fracture of a network. To execute the experirnents a circuit of size L x L was created, with the connections among the fuses orienteded by 45° with the direction of the applied potential difference. Two types of wires were used as fuses: copper wires and steel wool wires. The experirnents consisted in applying a potential difference V in the network and to measure the current I. The results were analyzed with the objective of determining their scaling laws changing the disorder or the network size. It was concluded that even for the totally disordered networks scaling laws were not observed. It was verified that for a fixed current above a certain critical current the electric resistance of the network intreases as a power law in time and also that the rupture time of the network decreases as a logarithmic law with the current for values slightly above the critical current, while for currents much larger than the critical current the rupture time decreases as a power law.
O objetivo deste trabalho é verificar, através de um estudo experimental do Modelo Aleatório de Fusíveis, como a orientação e a desordem da rede de fusíveis influenciam o processo de fratura da rede. Para a efetivação dos experimentos foi criado um circuito de tamanho L x L, com as ligações entre os fusíveis orientadas à 45° da direção de aplicação da diferença de potencial. Foram utilizados dois tipos de fios como fusíveis: fios de cobre e fios de palha de aço. Os experimentos consistiram em aplicar uma diferença de potencial V na rede e medir a corrente I. Os resultados obtidos foram analisados com o objetivo de se determinar suas leis de escala quando a desordem ou o tamanho da rede eram variados. Concluiu-se com os resultados que mesmo para as redes totalmente desordenada não foram observadas leis de escalas. Verificou-se ainda que para uma corrente fixa acima de certa corrente crítica, a resistência elétrica da rede aumenta como uma lei de potência do tempo e também que o tempo de ruptura da rede decai como uma lei logarítmica da corrente para valores de corrente pouco acima da corrente crítica, ao passo que para valores de corrente muito acima da corrente crítica o tempo de ruptura decai como uma lei de potência.
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Gomez, Juan Carlos. "H.B.C. fuse models based on fundamental arc mechanisms." Thesis, Sheffield Hallam University, 1994. http://shura.shu.ac.uk/6848/.
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The Thesis presents an in-depth study of arcing behaviour of H. B. C. Fuses for a range of fuse elements and fillers, under critical current conditions. The methodologies used were the standard breaking capacity short-circuit test plus the application of crow-bar, Xray studies, metallographic microscopic and optical fiber arc detection techniques. Due to the observation of some unknown and puzzling arc phenomena it was decided to pursue the arc investigation by an extensive test programme of single uniform wire fuse elements. From the investigation a basic arc mechanism for the pre-peak and post-peak arcs period was discovered. The new mechanism was applied to single wire, strip, long notched, medium notched and short notched fuse elements and to paralleled wires and strips immersed in three quartz filler types: standard sand, high quality granular quartz and bound quartz in two different sizes. The proposed arc mechanism was modelled by a computer program which was used to simulate the described fuse constructions. The results of over 800 tests and subsequent simulation undoubtedly confirm that the proposed arc mechanism is applicable for the described fuse types. The experimental and analytical results are close enough to justify the model application for fuse designers and fuse users. A critical comparison of the experimental and analytical results with previous findings published by other researchers is presented. A detailed arc mechanism and the key behaviour rules are proposed, they are: " Maximum column voltage can not exceed the arc-root voltage. " The arc-root voltage and the initial dv/dt values are influenced by filler characteristics and are able to precisely characterize the filler behaviour. " The dv/dt, and consequently the burn-back are instantaneous current density functions. The application of the above rules allows the fuse designer to tailor the fuse element in order to obtain specific current and arc voltage waveforms. It is believed that the proposed arc mechanism and computer model is able to explain some puzzling are phenomena and eventually could be applied to predicting other low overload H. B. C. fuse behaviour.
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Gogia, Neha. "Drosophila Eye Model to Study Dorso-Ventral (DV) Patterning and Neurodegenerative Disorders." University of Dayton / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=dayton1572279564626749.
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Kinc, Marek. "Numerická simulace výroby keramických jader pro technologii lití na vytavitelný model." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2015. http://www.nusl.cz/ntk/nusl-231964.
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The aim of this diploma thesis is validation of numerical simulation of the ceramic core manufacturing in the investment casting proces. The first part submit the theoretical description of the manufacturing of the ceramic cores and a description of the basic principles of numerical simulations. The second part compares the video recording of filling the wax-ceramic mixture to the die-casting mold and simulation of the same process created in a simulation software Cadmould 3D-F.
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Hebda, Michael J. "Creation of controlled polymer extrusion prediction methods in fused filament fabrication. An empirical model is presented for the prediction of geometric characteristics of polymer fused filament fabrication manufactured components." Thesis, University of Bradford, 2019. http://hdl.handle.net/10454/18399.
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This thesis presents a model for the procedures of manufacturing Fused Filament Fabrication (FFF) components by calculating required process parameters
using empirical equations. Such an empirical model has been required within the
FFF field of research for a considerable amount of time and will allow for an expansion in understanding of the fundamental mathematics of FFF. Data acquired
through experimentation has allowed for a data set of geometric characteristics
to be built up and used to validate the model presented. The research presented
draws on previous literature in the fields of additive manufacturing, machine engineering, tool-path programming, polymer science and rheology. Combining these
research fields has allowed for an understanding of the FFF process which has
been presented in its simplest form allowing FFF users of all levels to incorporate
the empirical model into their work whilst still allowing for the complexity of the
process.
Initial literature research showed that Polylactic Acid (PLA) is now in common
use within the field of FFF and therefore was selected as the main working material for this project. The FFF technique, which combines extrusion and Computer
Aided Manufacturing (CAM) techniques, has a relatively recent history with little understood about the fundamental mathematics governing the process. This
project aims to rectify the apparent gap in understanding and create a basis upon
which to build research for understanding complex FFF techniques and/or processes involving extruding polymer onto surfaces.
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Tian, Ye. "Knowledge-fused Identification of Condition-specific Rewiring of Dependencies in Biological Networks." Diss., Virginia Tech, 2014. http://hdl.handle.net/10919/52557.
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Gene network modeling is one of the major goals of systems biology research. Gene network modeling targets the middle layer of active biological systems that orchestrate the activities of genes and proteins. Gene network modeling can provide critical information to bridge the gap between causes and effects which is essential to explain the mechanisms underlying disease. Among the network construction tasks, the rewiring of relevant network structure plays critical roles in determining the behavior of diseases. To systematically characterize the selectively activated regulatory components and mechanisms, the modeling tools must be able to effectively distinguish significant rewiring from random background fluctuations. While differential dependency networks cannot be constructed by existing knowledge alone, effective incorporation of prior knowledge into data-driven approaches can improve the robustness and biological relevance of network inference. Existing studies on protein-protein interactions and biological pathways provide constantly accumulated rich domain knowledge. Though novel incorporation of biological prior knowledge into network learning algorithms can effectively leverage domain knowledge, biological prior knowledge is neither condition-specific nor error-free, only serving as an aggregated source of partially-validated evidence under diverse experimental conditions. Hence, direct incorporation of imperfect and non-specific prior knowledge in specific problems is prone to errors and theoretically problematic.
To address this challenge, we propose a novel mathematical formulation that enables incorporation of prior knowledge into structural learning of biological networks as Gaussian graphical models, utilizing the strengths of both measurement data and prior knowledge. We propose a novel strategy to estimate and control the impact of unavoidable false positives in the prior knowledge that fully exploits the evidence from data while obtains "second opinion" by efficient consultations with prior knowledge. By proposing a significance assessment scheme to detect statistically significant rewiring of the learned differential dependency network, our method can assign edge-specific p-values and specify edge types to indicate one of six biological scenarios. The data-knowledge jointly inferred gene networks are relatively simple to interpret, yet still convey considerable biological information. Experiments on extensive simulation data and comparison with peer methods demonstrate the effectiveness of knowledge-fused differential dependency network in revealing the statistically significant rewiring in biological networks, leveraging data-driven evidence and existing biological knowledge, while remaining robust to the false positive edges in the prior knowledge. We also made significant efforts in disseminating the developed method tools to the research community. We developed an accompanying R package and Cytoscape plugin to provide both batch processing ability and user-friendly graphic interfaces. With the comprehensive software tools, we apply our method to several practically important biological problems to study how yeast response to stress, to find the origin of ovarian cancer, and to evaluate the drug treatment effectiveness and other broader biological questions. In the yeast stress response study our findings corroborated existing literatures. A network distance measurement is defined based on KDDN and provided novel hypothesis on the origin of high-grade serous ovarian cancer. KDDN is also used in a novel integrated study of network biology and imaging in evaluating drug treatment of brain tumor. Applications to many other problems
also received promising biological results.Ph. D.
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Cone, Alan J. "Fission Yeast as a Model Organism for FUS-Dependent Cytotoxicity in Amyotrophic Lateral Sclerosis." Wright State University / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=wright1470750088.
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Alves, Fábio Alcino Carvalho. "Análise e otimização do processo Fused Filament Fabrication." Master's thesis, Universidade de Aveiro, 2014. http://hdl.handle.net/10773/14298.
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Mestrado em Engenharia MecânicaNo processo de impressão 3D por FFF, o equipamento deve manter as caraterísticas de funcionamento normais dentro de determinados parâmetros durante todas as fases do processo. Contudo, o excesso de temperatura em determinados componentes pode levar à interrupção do processo de impressão. Desta forma, torna-se imperativo analisar o processo e postular soluções que permitam re-conceber o sistema de modo a enfrentar esses desafios operacionais. O processo foi instrumentado e analisado, tendo-se ainda procedido ao desenvolvimento de um modelo que, por recurso à aplicação Flow Simulation do SolidWorks®, que no fim de devidamente validado, permitiu parametrizar e preconizar soluções de operação do equipamento atualmente no mercado. As soluções preconizadas foram efetivamente desenvolvidas no âmbito deste trabalho de dissertação, sendo os resultados observados experimentalmente muito próximos dos simulados. Assim, nesta dissertação, foi efetuado um estudo detalhado de todo o processo e definida uma estratégia de otimização do equipamento de FFF.
In 3D printing by FFF process, the product must maintain the characteristics of normal operating within certain parameters during all phases of the process. However, excessive temperature can lead to certain components in the interruption of the printing process. Thus, it becomes imperative to analyze the process and put forward solutions that enable re-design the system to meet these operational challenges. The process was instrumented and analyzed, and was also developed a model through of the application Flow Simulation of SolidWorks, that after validated adequately the parameters, become possible parameterize the solutions of operation of the equipment currently on the market. The solutions were effectively developed within this dissertation, the results are very close to those observed experimentally simulated. Thus, in this dissertation, was made a detailed study of the process and set a strategy for optimizing the FFF equipment.
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Furse, Devin Donaldson. "Optimization and Correlation of the Penn State Model of Friction Stir Welding to Experimental Welds in 304L Stainless Steel." BYU ScholarsArchive, 2010. https://scholarsarchive.byu.edu/etd/2524.
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A numerical model of friction stir welding developed by T. DebRoy, R. Nandan, and others has been optimized to fit experimental data of eleven welds of 304L stainless steel at various weld feed rates and spindle speeds. Optimization was used to determine the values of five difficult-to-measure model parameters. The optimal parameter values were then correlated to the weld machine inputs. The mechanical efficiency and the coefficient of friction were not correlated with feed rate, spindle speed, or axial pressure. Tool slip was positively correlated with feed rate, negatively correlated with spindle speed, and not correlated with axial pressure. The heat partition factor was positively correlated with feed rate, negatively correlated with spindle speed, and negatively correlated with axial pressure. The heat transfer coefficient at the bottom face was positively correlated with feed rate, not correlated with spindle speed, and positively correlated with axial pressure. The above welds were instrumented with thermocouples at the mid-plane of the workpiece. Recently acquired three-dimensional temperature data indicates that the two-dimensionally optimized model does not sufficiently capture the thermal profiles in all three directions. However, optimizing the model to fit the three-dimensional data does not yield acceptable results either. Several potential sources for model improvement are identified, primarily the modeling of heat transfer at the bottom surface. It is shown that using a spatially-variable thermal contact resistance approach is more theoretically justifiable and yields better temperature predictions.
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Killpack, Cody C. "Visualization of Three-Dimensional Models from Multiple Texel Images Created from Fused Ladar/Digital Imagery." DigitalCommons@USU, 2016. https://digitalcommons.usu.edu/etd/4637.
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The ability to create three-dimensional (3D) images offers a wide variety of solutions to meet ever increasing consumer demands. As popularity for 3D cinema and television continues to grow, 3D images will remain an important area of research and development. While there are a variety of ways to create a 3D model, textel images are quickly become the preferred solution that has been captured with a texel camera. The combination of multiple texel images taken around a scene can be used to form a texel model. Offering both visual and dimensional accuracy, texel models are becoming invaluable tools for disaster management, situational awareness, and even military application. However, displaying a texel model often provides challenges, and the problems that arise when viewing texel models will be discussed and corrected in this paper.
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Bourefis, Annis-Rayan. "Novel FUS and CHCHD10 models to investigate pathogenic mechanisms in Amyotrophic Lateral Sclerosis." Thesis, Sorbonne université, 2019. http://www.theses.fr/2019SORUS177.
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La sclérose latérale amyotrophique (SLA) est une maladie neurodégénérative dévastatrice causée par la dégénérescence progressive des motoneurones (MNs) supérieurs et inférieurs menant à une faiblesse et une atrophie musculaire qui progresse jusqu’à la paralysie. Deux gènes majeurs identifiés chez les patients SLA sont le gène FUS (FUSed in sarcoma), impliqué dans le métabolisme de l’ARN, et CHCHD10, qui joue un rôle dans la stabilité des mitochondries. Ces deux gènes ont été étudiés à travers différents modèles, de petits modèles invertébrés aux biopsies de patients. Cependant, les différents traits phénotypiques observés sont complexes et parfois controversés. L’objectif de cette thèse est de fournir de nouvelles informations sur l’implication de ces deux gènes dans la SLA à travers l’utilisation de nouveaux modèles. Pour étudier les mécanismes pathologiques induits par FUS et CHCHD10, nous avons généré et caractérisé deux nouveaux modèles de poisson-zèbres présentant une mutation non-sens des orthologues de ces gènes, et nous avons mis en évidence différents traits phénotypiques propres à la SLA. Nous avons montré, pour FUS, une espérance de vie réduite, une locomotion altérée, des axones moteurs aberrants, une jonction neuromusculaire (JNM) désorganisée, une altération des muscles et mitochondries, ainsi que des changements moléculaires. Ces résultats montrent que la perte de fonction de fus est responsable de l’apparition de signes pathologiques distaux au niveau de la JNM, indiquant une neuronopathie en « dying-back », dans laquelle les traits pathologiques de la SLA commencent au niveau de la JNM et progressent vers les corps cellulaires des MNsAmyotrophic Lateral Sclerosis (ALS) is a devastating neurodegenerative disorder caused by progressive degeneration of upper and lower motor neurons (MNs), with a very rapid clinical course. It leads to muscle weakness and atrophy progressing to paralysis, with respiratory failure being the major cause of death within years following clinical diagnosis. Two major genes mutated in ALS patients are the RNA-binding protein FUS (FUSed in sarcoma), implicated in RNA metabolism, and coiled-coil-helix-coiled-coil-helix domain 10 (CHCHD10), which plays a role in mitochondria stability. Both these genes have been investigated through different model systems, from small invertebrate models to patient biopsies. However, the major phenotypic features obtained in these models are complex and often controversial. The objective of this work is to provide new insights on the implication of these genes in ALS through the use of new models.To investigate the pathogenic mechanisms induced by FUS and CHCHD10, we generated and characterized two novel stable non-sense mutant zebrafish models for the orthologues of these genes and highlighted several ALS phenotypic features. We demonstrated, for the FUS model but not for CHCHD10, reduced lifespan, locomotor disabilities, aberrant motor axons, disorganized neuromuscular junction (NMJ), muscle and mitochondrial alteration, as well as molecular changes. These findings indicate that loss of fus expression is responsible for the occurrence of distal pathological signs at the NMJ, thus supporting a “dying-back” neuronopathy, in which early disease hallmarks start at the level of the NMJ and progress towards MN cell bodies
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Castro, Juan De Dios. "Engineered Nanocomposite Materials for Microwave/Millimeter-Wave Applications of Fused Deposition Modeling." Scholar Commons, 2017. http://scholarcommons.usf.edu/etd/6643.
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A variety of high-permittivity (high-k) and low-loss ceramic-thermoplastic composite materials as fused deposition modeling (FDM) feedstock, based on cyclo-olefin polymer (COP) embedded with sintered ceramic fillers, have been developed and investigated for direct digital manufacturing (DDM) of microwave components. The composites presented in this dissertation use a high-temperature sintering process up to 1500°C to further enhance the dielectric properties of the ceramic fillers. The electromagnetic (EM) properties of these newly developed FDM composites were characterized up to the Ku-band by using the cavity perturbation technique. Several models for prediction of the effective relative dielectric permittivity of composites based on the filler loading volume fraction have been evaluated, among which Hanai-Bruggeman and Maxwell models have shown the best accuracy with less than 2% and 5% discrepancies, respectively.
The 30 vol. % COP-TiO2 FDM-ready composites with fillers sintered at 1200°C have exhibited a relative permittivity (εr) of 4.78 and a dielectric loss tangent (tan δd) lower than 0.0012 at 17 GHz. Meanwhile, the 30 vol. % COP-MgCaTiO2 composites with fillers sintered at 1200°C have exhibited a εr of 4.82 and a tan δd lower than 0.0018. The DDM approach combines FDM of the engineered EM composites and micro-dispensing for deposition of conductive traces to fabricate by 3D-printing edge-fed patch antennas operating at 17.2 GHz and 16.5 GHz. These antennas were demonstrated by employing a 25 vol. % COP-MgCaTiO2 composite FDM filament with the fillers sintered at 1100°C and a pure COP filament, which were both prepared and extruded following the process described in this dissertation. The low dielectric loss of the 25 vol. % COP-MgCaTiO2 composite material (tan δd lower than 0.0018) has been leveraged to achieve a peak realized gain of 6 dBi. Also, the high-permittivity (εr of 4.74), which corresponds to an index of refraction of 2.17, results in a patch area miniaturization of 50% when compared with an antenna designed and DPAM-printed over a Rogers RT/duroid® 5870 laminate core through micro-dispensing of CB028 silver paste. This reference antenna exhibited a measured peak realized gain of 6.27 dBi that is comparable.
Also, two low-loss FDM-ready composite materials for DDM technologies are presented and characterized at V-band mm-wave frequencies. Pure COP thermoplastic exhibits a relative permittivity εr of 2.1 and a dielectric loss tangent tan δd below 0.0011 at 69 GHz, whereas 30 vol. % COP-MgCaTiO2 composites with fillers sintered at 1200°C exhibit a εr of 4.88 and a tan δd below 0.0070 at 66 GHz. To the best of my knowledge, these EM properties (combination of high-k and low-loss) are superior to other 3D-printable microwave materials reported by the scientific microwave community and are on par with materials developed for high-performance microwave laminates by RF/microwave industry as shown in Chapter 5 and Chapter 7 and summarized in Table 5.4 and Table 7.1. Meanwhile, the linear coefficient of thermal expansion (CTE) from -25°C to 100°C of the reinforced 30 vol. % COP-MgCaTiO2 composite with fillers sintered at 1200°C is 64.42 ppm/°C, which is about 20 ppm/°C lower when compared with pure ABS and 10 ppm/°C lower as compared to high-temperature polyetherimide (PEI) ULTEM™ 9085 resin from Stratasys, Ltd. The CTE at 20°C of the same composite material is 84.8 ppm/°C which is about 20 ppm/°C lower when compared with pure ABS that is widely used by the research community for 3D printed RF/microwave devices by FDM. The electromagnetic (EM) composites with tailored EM properties studied by this work have a great potential for enabling the next generation of high-performance 3D-printed RF/microwave devices and antennas operating at the Ku-band, K-band, and mm-wave frequencies.
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Iannetti, Alessandra. "Méthodes de diagnostic pour les moteurs de fusée à ergols liquides." Thesis, Université Paris-Saclay (ComUE), 2016. http://www.theses.fr/2016SACLS243.
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Cette thèse a pour objectif de démontrer l'intérêt des outils de diagnostic "intelligents" pour application sur les moteurs de fusée. En Europe beaucoup d'efforts ont été faits pour développer quelques techniques innovantes comme les réseaux neuronaux, les méthodes de suivi de raie vibratoire, ou l'identification paramétrique mais peu de résultats sont disponibles quant à la comparaison des performances de différents algorithmes. Un deuxième objectif de la thèse a été celui d'améliorer le système de diagnostic du banc d'essai Mascotte (ONERA/CNES). Il s'agit d'un banc de démonstration pour les moteurs de fusée de type cryogénique représentatif des conditions d'utilisation d'un vrai moteur. Les étapes de la thèse ont été en premier lieu de choisir et d'évaluer des méthodes de diagnostic à base de modèles, en particulier l'identification paramétrique et le filtre de Kalman, et de les appliquer pour le diagnostic d'un système critique du banc Mascotte: le circuit de refroidissement. Après une première validation des nouveaux algorithmes sur des données d'essais disponibles, un benchmark fonctionnel a été mis en place pour pouvoir comparer les performances des algorithmes sur différents types de cas de panne simulés. La dernière étape consiste à intégrer les algorithmes sur les ordinateurs du banc de contrôle de Mascotte pour pouvoir effectuer une évaluation applicative des performances et de leur intégrabilité à l'environnement informatique déjà en place. Un exemple simple de boucle de régulation intégrant l’information du diagnostic est aussi étudié pour analyser l’importance de telles méthodes dans le contexte plus large d’une régulation « intelligente » du bancThe main objective of this work is to demonstrate and analyze the potential benefits of advanced real time algorithms for rocket engines monitoring and diagnosis. In the last two decades in Europe many research efforts have been devoted to the development of specific diagnostic technics such as neural networks, vibration analysis or parameter identification but few results are available concerning algorithms comparison and diagnosis performances analysis.Another major objective of this work has been the improvement of the monitoring system of the Mascotte test bench (ONERA/CNES). This is a cryogenic test facility based in ONERA Palaiseau used to perform analysis of cryogenic combustion and nozzle expansion behavior representative of real rocket engine operations.The first step of the work was the selection of a critical system of the bench, the water cooling circuit, and then the analysis of the possible model based technics for diagnostic such as parameter identification and Kalman filters.Three new algorithms were developed, after a preliminary validation based on real test data, they were thoroughly analyzed via a functional benchmark with representative failure cases.The last part of the work consisted in the integration of the diagnosis algorithms on the bench computer environment in order to prepare a set-up for a future real time application.A simple closed loop architecture based on the new diagnostic tools has been studied in order to assess the potential of the new methods for future application in the context of intelligent bench control strategies
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Ma, Pulong. "Hierarchical Additive Spatial and Spatio-Temporal Process Models for Massive Datasets." University of Cincinnati / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1535635193581096.
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Ward, Catherine L. "The Cellular Consequences of FUS/TLS Depletion: A Loss of Function Model for Amyotrophic Lateral Sclerosis: A Dissertation." eScholarship@UMMS, 2014. https://escholarship.umassmed.edu/gsbs_diss/738.
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Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease characterized by the death of motor neurons, generally leading to paralysis and death within 3-5 years of onset. Over 50 different mutations in the gene encoding FUS/TLS (or FUS) will result in ALS, accounting for ~4% of all inherited cases. FUS is a multifunctional protein with important functions in DNA/RNA processing and stress response. How these mutations affect the structure or function of FUS protein and ultimately cause ALS is not known. The fact that mutations cause the protein to mislocalize from the nucleus to the cytoplasm of cells suggests that ALS pathogenesis may occur through a loss of nuclear function, gain of toxic cytoplasmic function, or both. Several FUS knockout animal models have been utilized for investigating a loss of function hypothesis and show phenotypes such as early lethality, reduced lifespan, and locomotor defects.
To uncover cellular pathways affected by loss of FUS function, I have characterized the knockdown of FUS in a motor neuron-like cell line, NSC-34. In NSC-34 cells, the depletion of FUS severely impacts cellular proliferation and potentially causes increased levels of DNA damage. A quantitative proteomics analysis performed on cells undergoing various degrees of FUS knockdown revealed protein expression changes for known RNA targets of FUS, consistent with a loss of FUS function with respect to RNA processing. Proteins that changed in expression as a function of FUS knockdown were associated with vii multiple processes, some of which influence cell proliferation including cell-cycle regulation, cytoskeletal organization, oxidative stress and energy homeostasis. Importantly, cellular proliferation could be rescued by the re-expression of FUS and by treatment with the small-molecule, rolipram, indicative of potential therapeutic approaches.
Collectively, the work presented in this dissertation demonstrates the importance of FUS for cell health and homeostasis, is suggestive of a role for FUS in DNA damage repair and identifies additional cellular pathways influenced by FUS depletion. Overall, this work provides mechanistic insight into ALS pathogenesis through loss of FUS/TLS function.
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Ward, Catherine L. "The Cellular Consequences of FUS/TLS Depletion: A Loss of Function Model for Amyotrophic Lateral Sclerosis: A Dissertation." eScholarship@UMMS, 2007. http://escholarship.umassmed.edu/gsbs_diss/738.
Full textAbstract:
Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease characterized by the death of motor neurons, generally leading to paralysis and death within 3-5 years of onset. Over 50 different mutations in the gene encoding FUS/TLS (or FUS) will result in ALS, accounting for ~4% of all inherited cases. FUS is a multifunctional protein with important functions in DNA/RNA processing and stress response. How these mutations affect the structure or function of FUS protein and ultimately cause ALS is not known. The fact that mutations cause the protein to mislocalize from the nucleus to the cytoplasm of cells suggests that ALS pathogenesis may occur through a loss of nuclear function, gain of toxic cytoplasmic function, or both. Several FUS knockout animal models have been utilized for investigating a loss of function hypothesis and show phenotypes such as early lethality, reduced lifespan, and locomotor defects.
To uncover cellular pathways affected by loss of FUS function, I have characterized the knockdown of FUS in a motor neuron-like cell line, NSC-34. In NSC-34 cells, the depletion of FUS severely impacts cellular proliferation and potentially causes increased levels of DNA damage. A quantitative proteomics analysis performed on cells undergoing various degrees of FUS knockdown revealed protein expression changes for known RNA targets of FUS, consistent with a loss of FUS function with respect to RNA processing. Proteins that changed in expression as a function of FUS knockdown were associated with vii multiple processes, some of which influence cell proliferation including cell-cycle regulation, cytoskeletal organization, oxidative stress and energy homeostasis. Importantly, cellular proliferation could be rescued by the re-expression of FUS and by treatment with the small-molecule, rolipram, indicative of potential therapeutic approaches.
Collectively, the work presented in this dissertation demonstrates the importance of FUS for cell health and homeostasis, is suggestive of a role for FUS in DNA damage repair and identifies additional cellular pathways influenced by FUS depletion. Overall, this work provides mechanistic insight into ALS pathogenesis through loss of FUS/TLS function.
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Volgina, Vera. "Postmerger financial performance: econometric analysis." Master's thesis, Vysoká škola ekonomická v Praze, 2009. http://www.nusl.cz/ntk/nusl-16850.
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There are numerous researches done in the last couple decades dedicated to the observation of impact of merges and acquisitions on the performance of the company. The topic is considered to be up-to-date, as still there is no common approach to evaluating of benefits mergers are about to bring to a new established entity. In this thesis the issue of post-merger financial performance is investigated on an example of three biggest energy companies in Europe: RWE, E.ON and Vattenfall. The aim of the thesis is to find out whether financial performance of chosen companies improves after the merger occurs. This target is elaborated with a help of the analysis of commonly used financial ratios in corporate finance and construction of two regression models, which explain the interrelations between basic indicator of the company's growth (net income), the fact of the merger and determined financial ratios. As an outcome of the research, a few findings were obtained, such as worsening of financial performance three to five years after the merger, with continuing improvement in further years, quite stable financial indicators before the merger, positive interconnection between the fact of the merger and the net income. Such outcomes might be considered as significant, though further research and elaboration of the topic can be performed in the future.
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Oddie, Jonathan J. "Counterpoint, 'fuge', and 'air' in the instrumental music of Orlando Gibbons." Thesis, University of Oxford, 2015. https://ora.ox.ac.uk/objects/uuid:eae0a0b5-9cf2-41af-bca0-eb8db9cfcb40.
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This thesis develops an analytical approach to the instrumental music of Orlando Gibbons (1583-1625) based on close readings of historical theory sources, primarily by Thomas Morley, John Coprario and Thomas Campion. Music of the early seventeenth century can be difficult to analyse, since it falls between the more extensively studied and theorised practices of classic vocal polyphony and common-practice tonality. Although English music theory of this period is recognised as strikingly modern in many respects, innovative aspects of English compositions from the same period receive little attention in standard accounts of the seventeenth century. I argue that concepts taken from this body of historical theory provide the basic terms of a technical vocabulary for analysis, which should be further refined through application to real compositions. Successive chapters deal with common counterpoint models or patterns, imitative invention and disposition, cadential progressions, and overall tonal structure. I argue that these analyses show Gibbons's music to be a contribution to new ways of conceiving of instrumental polyphony and tonal structure, which deserves re-evaluation in the context of broader seventeenth-century trends. In particular, Gibbons's use of extended cadential expectations as an expressive element, fascination with sequential progressions, and sectional structuring by harmonic area have clear parallels with later practices. At the same time, early seventeenth century style allows the composer considerably more freedom of harmonic procedures and implications than the musical styles which immediately followed it. Analysis grounded in historical theory provides the best approach to understanding and appreciating this unique musical language.
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Shen, Sumin. "Contributions to Structured Variable Selection Towards Enhancing Model Interpretation and Computation Efficiency." Diss., Virginia Tech, 2020. http://hdl.handle.net/10919/96767.
Full textAbstract:
The advances in data-collecting technologies provides great opportunities to access large sample-size data sets with high dimensionality. Variable selection is an important procedure to extract useful knowledge from such complex data. While in many real-data applications, appropriate selection of variables should facilitate the model interpretation and computation efficiency. It is thus important to incorporate domain knowledge of underlying data generation mechanism to select key variables for improving the model performance. However, general variable selection techniques, such as the best subset selection and the Lasso, often do not take the underlying data generation mechanism into considerations. This thesis proposal aims to develop statistical modeling methodologies with a focus on the structured variable selection towards better model interpretation and computation efficiency. Specifically, this thesis proposal consists of three parts: an additive heredity model with coefficients incorporating the multi-level data, a regularized dynamic generalized linear model with piecewise constant functional coefficients, and a structured variable selection method within the best subset selection framework.
In Chapter 2, an additive heredity model is proposed for analyzing mixture-of-mixtures (MoM) experiments. The MoM experiment is different from the classical mixture experiment in that the mixture component in MoM experiments, known as the major component, is made up of sub-components, known as the minor components. The proposed model considers an additive structure to inherently connect the major components with the minor components. To enable a meaningful interpretation for the estimated model, we apply the hierarchical and heredity principles by using the nonnegative garrote technique for model selection. The performance of the additive heredity model was compared to several conventional methods in both unconstrained and constrained MoM experiments. The additive heredity model was then successfully applied in a real problem of optimizing the Pringlestextsuperscript{textregistered} potato crisp studied previously in the literature.
In Chapter 3, we consider the dynamic effects of variables in the generalized linear model such as logistic regression. This work is motivated from the engineering problem with varying effects of process variables to product quality caused by equipment degradation. To address such challenge, we propose a penalized dynamic regression model which is flexible to estimate the dynamic coefficient structure. The proposed method considers modeling the functional coefficient parameter as piecewise constant functions. Specifically, under the penalized regression framework, the fused lasso penalty is adopted for detecting the changes in the dynamic coefficients. The group lasso penalty is applied to enable a sparse selection of variables. Moreover, an efficient parameter estimation algorithm is also developed based on alternating direction method of multipliers. The performance of the dynamic coefficient model is evaluated in numerical studies and three real-data examples.
In Chapter 4, we develop a structured variable selection method within the best subset selection framework. In the literature, many techniques within the LASSO framework have been developed to address structured variable selection issues. However, less attention has been spent on structured best subset selection problems. In this work, we propose a sparse Ridge regression method to address structured variable selection issues. The key idea of the proposed method is to re-construct the regression matrix in the angle of experimental designs. We employ the estimation-maximization algorithm to formulate the best subset selection problem as an iterative linear integer optimization (LIO) problem. the mixed integer optimization algorithm as the selection step. We demonstrate the power of the proposed method in various structured variable selection problems. Moverover, the proposed method can be extended to the ridge penalized best subset selection problems. The performance of the proposed method is evaluated in numerical studies.Doctor of Philosophy
The advances in data-collecting technologies provides great opportunities to access large sample-size data sets with high dimensionality. Variable selection is an important procedure to extract useful knowledge from such complex data. While in many real-data applications, appropriate selection of variables should facilitate the model interpretation and computation efficiency. It is thus important to incorporate domain knowledge of underlying data generation mechanism to select key variables for improving the model performance. However, general variable selection techniques often do not take the underlying data generation mechanism into considerations. This thesis proposal aims to develop statistical modeling methodologies with a focus on the structured variable selection towards better model interpretation and computation efficiency. The proposed approaches have been applied to real-world problems to demonstrate their model performance.
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Zandi, Mohammad Damous. "Study and characterization of mechanical properties of wood-PLA composite (Timberfill) material parts built through fused filament fabrication." Doctoral thesis, Universitat Politècnica de Catalunya, 2020. http://hdl.handle.net/10803/669587.
Full textAbstract:
This research is based upon the additive manufacturing (AM) technology which aims to study the mechanical properties of innovative commercial wood-PLA composite material (Timberfill) and characterize its behavior. Specifically fatigue, tensile, and flexural tests are performed and the results are evaluated to conclude this issue. To manufacture the experimental samples one of the most common techniques named fused filament fabrication (FFF) is applied, consequently the influence of manufacturing parameters on the mechanical properties have been considered. For this reason some of the most influential printing parameters in different levels are selected and have been combined together to manufacture the samples in a wide range of building conditions. To avoid manufacturing a large number of specimens, a design of experiments (DoE) through Taguchi orthogonal arrays is designed and the influence of the factors have been analyzed performing an analysis of variance (ANOVA). As a conclusion the optimal combination of the parameters and levels have been obtained for each one of the applied mechanical tests and higher values of responses have been derived from these set of parameters. Since the above mentioned material is composite of wood fibers with PLA, all of the obtained results are compared to the pure PLA to find the effectiveness of this composition.
In the other side tensile and flexural tests have been applied on solid Timberfill specimens manufactured through injection molding to investigate the differences between this technology and additive manufacturing. These investigations resulted that mechanical resistances of the printed samples were lower than injected ones which the solidity percentage could be main reason of this effect.
Additionally the flexural strength of the material have been simulated and compare to the experimental results. The achieved deformation behavior curves validate the experimental test and that would be one of the main conclusions of this research.Esta investigación se basa en la tecnología de fabricación aditiva (AM) y tiene como objetivo estudiar las propiedades mecánicas y caracterizar el comportamiento de un material comercial innovador, compuesto de PLA con fibras de madera (Timberfill). Específicamente, se realizan pruebas de fatiga, tracción y flexión y se evalúan los resultados para concluir sobre los mismos. Para fabricar las muestras experimentales se aplica una de las técnicas más comunes llamadas fabricación de filamentos fundidos (FFF), y se ha considerado la influencia de los parámetros de fabricación en las propiedades mecánicas de las mismas. Por esta razón, se han seleccionado algunos de los parámetros de impresión más influyentes en diferentes niveles y se han combinado para fabricar las muestras en una amplia gama de condiciones de construcción. Para evitar la fabricación de una gran cantidad de muestras, se ha utilizado un diseño de experimentos (DoE) a través de matrices ortogonales de Taguchi y se ha analizado la influencia de los factores realizando un análisis de varianza (ANOVA). Como conclusión, se ha obtenido la combinación óptima de los parámetros y niveles para cada una de las pruebas mecánicas realizadas y se han detectado los valores más altos de respuestas de éstos. Dado que el material mencionado anteriormente es un compuesto de PLA con fibras de madera, todos los resultados obtenidos se comparan con el PLA puro para encontrar la efectividad de esta composición. Por otro lado, se han realizado también pruebas de tracción y flexión a muestras sólidas de Timberfill fabricadas mediante moldeo por inyección para investigar las diferencias entre esta tecnología y la fabricación aditiva. Los resultados muestran que la resistencia mecánica de las muestras impresas es más bajas que las inyectadas, por lo que el porcentaje de solidez podría ser la razón principal de este efecto. Además, la resistencia a la flexión del material se ha simulado y comparado con los resultados experimentales. Las curvas de comportamiento de deformación logradas validan la prueba experimental lo cual es una de las principales conclusiones de esta investigación.
Aquesta investigació es basa en la tecnologia de fabricació additiva (AM) i té com a objectiu estudiar les propietats mecàniques i caracteritzar el comportament d'un material comercial innovador, format de PLA amb fibres de fusta (Timberfill). Específicament, es realitzen proves de fatiga, tracció i flexió i s'avaluen els resultats per concloure sobre els mateixos. Per fabricar les mostres experimentals s'aplica una de les tècniques més comunes anomenada fabricació de filaments fosos (FFF), i s'ha considerat la influència dels paràmetres de fabricació en les propietats mecàniques de les mateixes. Per aquesta raó, s'han seleccionat alguns dels paràmetres d'impressió més influents en diferents nivells i s'han combinat per fabricar les mostres en una àmplia gamma de condicions de construcció. Per evitar la fabricació d'una gran quantitat de mostres, s'ha utilitzat un disseny d'experiments (DoE) a través de matrius ortogonals de Taguchi i s'ha analitzat la influència dels factors realitzant una anàlisi de variància (ANOVA). Com a conclusió, s'ha obtingut la combinació òptima dels paràmetres i nivells per a cadascuna de les proves mecàniques realitzades i s'han detectat els valors més alts de respostes d'aquests. Atès que el material esmentat anteriorment és un compost de PLA amb fibres de fusta, tots els resultats obtinguts es comparen amb el PLA pur per trobar l'efectivitat d'aquesta composició. D'altra banda, s'han realitzat també proves de tracció i flexió a mostres sòlides de Timberfill fabricades mitjançant el procediment d’injecció per investigar les diferències entre aquesta tecnologia i la fabricació additiva. Els resultats mostren que la resistència mecànica de les mostres impreses és més baixes que les injectades, de manera que el percentatge de solidesa podria ser la raó principal d'aquest efecte. A més, la resistència a la flexió del material s'ha simulat i comparat amb els resultats experimentals. Les corbes de comportament de deformació assolides validen la prova experimental la qual cosa és una de les principals conclusions d'aquesta investigació.
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JOSSEFA, Célio Gregório de Vasconcelos. "Uso de redes neurais artificiais e métodos tradicionais na estimativa do volume do fuste de Eucalyptus spp., na região do Polo Gesseiro do Araripe." Universidade Federal Rural de Pernambuco, 2016. http://www.tede2.ufrpe.br:8080/tede2/handle/tede2/7405.
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Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq
One of the ways to estimate volumes of the Eucalyptus trees with efficiency is to apply formulae that can make the estimates with precision. The objective of this work was to compare two ways of volume estimations: mathematical models through regression methods and the artificial neural networks. The data set used came from the second rotation of the experiment containing 15 clones, of Eucalyptus spp., implanted at the Experimental Station of the Agronomic Institute of Pernambuco (IPA), located in the Araripe region, Pernambuco, Brazil. The data set was composed of 2199 trees, cubed by the Smalian method. It was measured the total height, stem height and diameters at several position in the bole. For modeling, the trees were grouped using the Skott-Knott test, per clone and for all the clones together. The evaluation of Artificial Neural Network (ANN) adjustments considered two forms of input of the independent variables: a) volume sections and b) diameter at breast height (DBH) and total height (Ht). The performance of the mathematical volumetric models and ANN was based on Schlaegel fitting index (IAaj), root mean squared error in percentage (RMSE%) and graphic residuals analysis. According to the results, the Schumacher-Hall model presented better statistical performance for estimating the individual volume of Eucalyptus spp. The Artificial Neural Network considering the volume of the sections as input variables was superior when comparing with DBH and Ht as input variables. The Silva-Borders model and Artificial Neural Networks considering the volume of the sections as input variables are more practical to measure volumes because they do not consider the variable Ht, which is often difficult to measure in the field and costly.
Uma das maneiras de tornar mais eficiente a estimativa do volume das árvores de Eucalipto é a aplicação de ferramentas capazes de tornar as estimativas bem próximas do real. O objetivo deste trabalho foi comparar duas formas de estimativas de volume: modelos matemáticos por meio de métodos de regressão e redes neurais artificiais. O conjunto de dados utilizado resultou da segunda rotação do experimento contendo 15 clones, de Eucalyptus spp., Implantados na Estação Experimental do Instituto Agronômico de Pernambuco (IPA), localizada na região de Araripe, Pernambuco. O conjunto de dados foi composto por 2199 árvores, cubadas pelo método de Smalian. Foi mensurada a altura total, altura do fuste e diâmetros em várias posições no fuste. Para modelagem, as árvores foram agrupadas utilizando o teste de Skott-Knott, por clone e para todos os clones juntos. A avaliação dos ajustes da Rede Neural Artificial (RNA) considerou duas formas de entrada das variáveisindependentes: a) seções de volume e b) diâmetro à altura do peito (DAP) e altura total (Ht). O desempenho dos modelos matemáticos e RNA foi baseado no índice de adaptação de Schlaegel (𝐼𝐴𝑎𝑗), erro quadrático médio em percentual (RMSE%) e análise gráfica de resíduos. De acordo com os resultados obtidos, o modelo de Schumacher-Hall apresentou melhor desempenho estatístico para estimar o volume individual de Eucalyptus spp. A Rede Neural Artificial considerando o volume das seções como variáveis de entrada foi superior quando comparado com DAP e Ht como variáveis de entrada. O modelo de Silva-Borders e as Redes Neurais Artificiais considerando o volume das seções como variáveis de entrada são mais práticos para estimar o volume porque não consideram a variável Ht, que é muitas vezes difícil de medir no campo e onerosa.
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Kent, Louisa. "The molecular pathogenesis of FUS mutations in amyotrophic lateral sclerosis using in vivo and in vitro models." Thesis, University of Oxford, 2015. https://ora.ox.ac.uk/objects/uuid:f0968f9d-db01-4ace-bbd7-fc43319e19ea.
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Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease characterised by degeneration of both upper and lower motor neurons. Most ALS occurs in a sporadic manner, though 5-10% is familial. Fused in sarcoma (FUS) is an RNA binding protein, and mutations in the FUS gene are responsible for approximately 4% of familial and < 1% of sporadic ALS cases. This work uses in vitro and in vivo models to examine the cellular effects of FUS mutations and the potential mechanisms of motor neuron toxicity. The first section describes a family with a severe clinical form of ALS due to a FUS truncation mutation p.G504Wfs*12. This mutation demonstrates a severe phenotype in vitro, with mislocalisation of mutant FUS from the nucleus to the cytoplasm, and co-localisation with stress granules. Comparing these results with other mutations highlights the correlation between FUS mislocalisation and clinical phenotype, suggesting that the distribution of FUS plays a role in the pathogenesis of ALS. The next section explores the phenotype of primary motor neurons from a FUS BAC transgenic mouse model expressing low levels of wild-type or P525L human FUS. P525L-FUS shows marked mislocalisation to the cytoplasm and co-localisation with stress granules, with evidence of reduced survival and alterations in stress granule dynamics. This suggests that motor neurons expressing mutant FUS show inherent vulnerability. The final section explores transcript levels and alternative splicing in both FUS and TDP-43 BAC transgenic mouse models. Key proteins such as TDP-43, FUS and SMN show alterations in mRNA levels in CNS tissue, and some subtle splicing alterations are described. This work suggests that mutations in FUS are likely to affect motor neurons even when expressed at very low levels. Alterations in FUS distribution, stress granule dynamics, and regulation of transcription may all play a part in conferring a susceptibility to developing ALS.
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Bosch, Michaela [Verfasser], Wolfgang [Akademischer Betreuer] Wurst, and Heiko [Akademischer Betreuer] Lickert. "Generation and analysis of FUS and TMEM106B mouse models / Michaela Bosch. Betreuer: Wolfgang Wurst. Gutachter: Wolfgang Wurst ; Heiko Lickert." München : Universitätsbibliothek der TU München, 2015. http://d-nb.info/1080299351/34.
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Kim, Byung-Jun. "Semiparametric and Nonparametric Methods for Complex Data." Diss., Virginia Tech, 2020. http://hdl.handle.net/10919/99155.
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A variety of complex data has broadened in many research fields such as epidemiology, genomics, and analytical chemistry with the development of science, technologies, and design scheme over the past few decades. For example, in epidemiology, the matched case-crossover study design is used to investigate the association between the clustered binary outcomes of disease and a measurement error in covariate within a certain period by stratifying subjects' conditions. In genomics, high-correlated and high-dimensional(HCHD) data are required to identify important genes and their interaction effect over diseases. In analytical chemistry, multiple time series data are generated to recognize the complex patterns among multiple classes. Due to the great diversity, we encounter three problems in analyzing those complex data in this dissertation. We have then provided several contributions to semiparametric and nonparametric methods for dealing with the following problems: the first is to propose a method for testing the significance of a functional association under the matched study; the second is to develop a method to simultaneously identify important variables and build a network in HDHC data; the third is to propose a multi-class dynamic model for recognizing a pattern in the time-trend analysis.
For the first topic, we propose a semiparametric omnibus test for testing the significance of a functional association between the clustered binary outcomes and covariates with measurement error by taking into account the effect modification of matching covariates. We develop a flexible omnibus test for testing purposes without a specific alternative form of a hypothesis. The advantages of our omnibus test are demonstrated through simulation studies and 1-4 bidirectional matched data analyses from an epidemiology study.
For the second topic, we propose a joint semiparametric kernel machine network approach to provide a connection between variable selection and network estimation. Our approach is a unified and integrated method that can simultaneously identify important variables and build a network among them. We develop our approach under a semiparametric kernel machine regression framework, which can allow for the possibility that each variable might be nonlinear and is likely to interact with each other in a complicated way. We demonstrate our approach using simulation studies and real application on genetic pathway analysis.
Lastly, for the third project, we propose a Bayesian focal-area detection method for a multi-class dynamic model under a Bayesian hierarchical framework. Two-step Bayesian sequential
procedures are developed to estimate patterns and detect focal intervals, which can be used
for gas chromatography. We demonstrate the performance of our proposed method using
a simulation study and real application on gas chromatography on Fast Odor Chromatographic
Sniffer (FOX) system.Doctor of Philosophy
A variety of complex data has broadened in many research fields such as epidemiology, genomics, and analytical chemistry with the development of science, technologies, and design scheme over the past few decades. For example, in epidemiology, the matched case-crossover study design is used to investigate the association between the clustered binary outcomes of disease and a measurement error in covariate within a certain period by stratifying subjects' conditions. In genomics, high-correlated and high-dimensional(HCHD) data are required to identify important genes and their interaction effect over diseases. In analytical chemistry, multiple time series data are generated to recognize the complex patterns among multiple classes. Due to the great diversity, we encounter three problems in analyzing the following three types of data: (1) matched case-crossover data, (2) HCHD data, and (3) Time-series data. We contribute to the development of statistical methods to deal with such complex data. First, under the matched study, we discuss an idea about hypothesis testing to effectively determine the association between observed factors and risk of interested disease. Because, in practice, we do not know the specific form of the association, it might be challenging to set a specific alternative hypothesis. By reflecting the reality, we consider the possibility that some observations are measured with errors. By considering these measurement errors, we develop a testing procedure under the matched case-crossover framework. This testing procedure has the flexibility to make inferences on various hypothesis settings. Second, we consider the data where the number of variables is very large compared to the sample size, and the variables are correlated to each other. In this case, our goal is to identify important variables for outcome among a large amount of the variables and build their network. For example, identifying few genes among whole genomics associated with diabetes can be used to develop biomarkers. By our proposed approach in the second project, we can identify differentially expressed and important genes and their network structure with consideration for the outcome. Lastly, we consider the scenario of changing patterns of interest over time with application to gas chromatography. We propose an efficient detection method to effectively distinguish the patterns of multi-level subjects in time-trend analysis. We suggest that our proposed method can give precious information on efficient search for the distinguishable patterns so as to reduce the burden of examining all observations in the data.
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Dou, Zhifeng. "Sûreté de fonctionnement des convertisseurs - Nouvelles structures de redondances pour onduleurs sécurisés à tolérance de pannes." Thesis, Toulouse, INPT, 2011. http://www.theses.fr/2011INPT0096/document.
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Au sein d'un convertisseur la défaillance d'un composant de puissance est un événement critique tant par le risque d'explosion du boitier et sa propagation au sein du système (forte énergie stockée dans l'alimentation) que par l'interruption de service qui en découle (systèmes embarqués, systèmes de production en flux tendu). Ce mémoire de thèse propose un ensemble de solutions nouvelles portant sur la problématique de l'isolement ultime de défauts "derniers secours" d'une part, et sur la connexion "automatique" et à faible "coût" d'un circuit en secours. L'objectif de cette approche globale est de concilier "sécurité électrique absolue" et "continuité de service" pour les systèmes de conversion sensibles devant être intégrés au coeur des applications critiques. Le premier chapitre et son annexe permettent de rappeler les causes et les conséquences des défauts internes au sein d'une structure de base d'onduleur à deux niveaux de tension, laquelle fait l'objet de nombreuses simulations de modes dégradés en configuration variateur de vitesse sur machine synchrone. De cette analyse il ressort qu'une structure d'isolement symétrique à deux voies couplées, placées sur les pôles du bus DC, à déclenchement spontané (fusible) et/ou commande (rupteur), est à même de sécuriser toutes les mailles du circuit, de façon modulaire et non intrusiveIn all these traditional industries, or in more sensitive sectors and high technology, it appears that the safe operation of power systems becomes a critical and strategic area essential. In the area of application that focuses, design dependability and now rests primarily on an approach to reliability of components used, the use of close protection, monitoring alarms and management stop / reset / recovery. In our view, this approach is incomplete quickly when electrical safety and absolute continuity of a permanent mission should be carried out simultaneously in the presence of an internal failure of sensitive functions for low and medium power (eg, orders and bodies actuation of vehicles) or highly critical (nuclear). In this area, topologies and failure modes are at the heart of the problem. In this paper, we will focus primarily on the inverters and choppers structures at two levels of voltage (single-cell arm, <1kV), with simple configuration and multiphase parallel, although the concepts are presented, as examples, partially extrapolated to the structures of three voltage levels (arms multicellular) and rectifier (low-frequency phase control and high-frequency switching PWM). We will highlight the need to limit the intensity of these failures and to electrically isolate the defective cell and symmetrically of this inverter by multipole devices, passive or spontaneous breaking mixed cut ordered in the form of fuses integrated and distributed of multi-channel passive isolators, to imagine and develop. We will show that this process of isolation of the last backup is needed to connect, form series or parallel to the defective cell, a cell rescue in passive redundancy. The cell structure backup connection pooled by spontaneous (automatic) is especially promising as detailed in our eyes because of its simplicity and its integrability. Next, we present the isolation technologies fuse (not included, miniatures, CMS and multilayer chip fuse), their characteristics, their current limitations and operating in a switching cell test. A methodology and design of symmetrical two-way fuse (dual-fuse) on FR4 PCB - Copper will be presented in Comsol ™ and evaluated initially in static thermal IR. A passive two-way switch, relatively original material for integrating energy embedded in FR4 substrate, will be presented and fully dimensioned plans on electrical, thermal and mechanical also using finite element simulations in Comsol ™. Another aspect of exploratory analysis, mainly experimental, or to characterize the failure modes of bullets and casings ultimate power compared between the technologies of encapsulation by epoxy resin (standard discrete case) and a silicone gel (module) is provided under conditions of stress controlled and reproducible. This step is necessary to characterize the resistive mode of a chip based on faulty stresses and stability over time of the residual strength according to the nature of the encapsulant, ie the very sustainability of this failure mode. A mixed-encapsulant resin - gel will be presented and characterized, providing an excellent compromise for medium power applications. Positive results and little known today, will allow us to exploit in the next chapter, this property of stable ohmic mode of the chip failed in a structure to aid automated connection series interesting. In the end, we will detail the demonstrator prototype and introduced to the context with which we will validate the isolation structures and prototypes fuses the property of stable ohmic mode highlighted in the aspect of technological analysis of selected devices. These results allow us to refine the solutions adopted for specifications and guide future management strategy of defects whether internal or external to the topology. Supervisor digital device - sensor for the detection and reconfiguration of internal control orders will be assessed
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Pérez, Roca Sergio. "Model-based robust transient control of reusable liquid-propellant rocket engines." Thesis, université Paris-Saclay, 2020. http://www.theses.fr/2020UPASS017.
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La tendance actuelle vers un accès plus abordable à l'espace se traduit par des lanceurs et moteurs réutilisables. Du point de vue du contrôle, ces moteurs fusée à propergol liquide (MFPL) réutilisables impliquent des spécifications de robustesse plus exigeantes que ceux à usage unique, principalement en raison de leurs capacités de redémarrage multiple et de modulation de poussée. Classiquement, le système de contrôle gère les opérations des MFPL autour d'un ensemble fini de points prédéfinis. Cette approche réduit leur domaine de modulation à un intervalle restreint dans lequel ils sont conçus pour être sûrs. De plus, les phases transitoires, qui ont un impact important sur la vie du moteur, ne sont pas exécutées de manière robuste. L’objectif de ce travail est donc de développer une boucle de régulation adaptée à l’ensemble des phases d'opération (transitoire et régime permanent) et robuste aux variations paramétriques internes. Plusieurs blocs ont été développés pour constituer la boucle de régulation : simulation de moteur, génération de référence et contrôleurs. Des simulateurs représentatifs des moteurs à cycle générateur de gaz ont tout d'abord été construits. La modélisation purement thermodynamique du cycle a ensuite été adaptée au contrôle, afin d'obtenir des modèles non-linéaires sous forme d'état. Dans ces modèles, l'influence des entrées de commande continues (ouvertures des vannes) et des entrées discrètes (activation des allumeurs et démarreur) est considérée dans un cadre hybride simplifié. La sous-phase continue du transitoire de démarrage est contrôlée en boucle fermée pour suivre des trajectoires de référence pré-calculées. Outre le démarrage, les scénarios de modulation présentent également un algorithme pour le suivi des états finaux. Une méthode de contrôle à base de modèles, la commande prédictive, a été appliquée de manière linéarisée avec des considérations de robustesse à tous ces scénarios, dans lesquels des contraintes dures doivent être respectées. Le suivi des points de fonctionnement en pression (poussée) et du rapport de mélange dans l'enveloppe de conception est atteint en simulation tout en respectant les contraintes. La robustesse aux variations des paramètres, qui sont identifiés comme prédominants par des analyses, est également démontrée. Ce travail ouvre la voie à la validation expérimentale par des simulations hardware-in-the-loop ou des tests sur banc d'essaiThe current trend towards a more affordable access to space is materialising in reusable launchers and engines. From the control perspective, these reusable liquid-propellant rocket engines (LPRE) imply more demanding robustness requirements than expendable ones, mainly due to their multi-restart and thrust-modulation capabilities. Classically, the control system handles LPRE operation at a finite set of predefined points. That approach reduces their throttability domain to a narrow interval in which they are designed to be safe. Moreover, transient phases, which have a great impact on engine life, are not robustly operated. Hence, the goal of this work is to develop a control loop which is adapted to the whole set of operating phases, transient and steady-state, and which is robust to internal parametric variations. Several blocks have been developed to constitute the control loop: engine simulation, reference generation and controllers. First, simulators representative of the gas-generator-cycle engines were built. The purely thermo-fluid-dynamic modelling of the cycle was subsequently adapted to control, obtaining nonlinear state-space models. In these models, the influence of continuous control inputs (valve openings) and of discrete ones (igniters and starter activations) is considered within a simplified hybrid approach. The continuous sub-phase of the start-up transient is feedback controlled to track pre-computed reference trajectories. Beyond the start-up, throttling scenarios also present an end-state-tracking algorithm. A model-based control method, Model Predictive Control, has been applied in a linearised manner with robustness considerations to all these scenarios, in which a set of hard constraints must be respected. Tracking of pressure (thrust) and mixture-ratio operating points within the design envelope is achieved in simulation while respecting constraints. Robustness to variations in the parameters, which are checked to be predominant according to analyses, is also demonstrated. This framework paves the way to experimental validation via hardware-in-the-loop simulations or in test benches
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Zubricky, James R. III. "Physical Models of Biochemicallly Important Molecules Using Rapid Prototyping Techniques." Bowling Green State University / OhioLINK, 2006. http://rave.ohiolink.edu/etdc/view?acc_num=bgsu1151350496.
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Vašek, Vojtěch. "Použití modelů zhotovených technologii 3D tisku při výrobě odlitků do bentonitových forem na formovací lince." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2017. http://www.nusl.cz/ntk/nusl-319282.
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Shortening of the time required to make first product after demand is a crucial factor in every field of industry, not excluding the foundry. To lower this delay, there are rapid prototyping methods. The aim of this thesis is to execute an experiment and then evaluate possibilities of using patterns made by 3D FDM printer on an automatic molding line.
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Prudík, Jiří. "Model metropolitní optické sítě." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2008. http://www.nusl.cz/ntk/nusl-217666.
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The purpose of this master’s thesis is foremost to provide a simple guide how to build elements of optical metropolitan area network. The basic model consists to sequence of construction, network topology, passive and active parts. The collection contains examples of alternative technology such as Wireless LAN with different frequency. The optical network construction based on optical cable, fibres, splices, trays, adapters, connectors and active parts for example a lot of media convertor models. After that there are demonstrating type of wavelength division multiplexer used in metropolitan area network – passive planar PCL splitter. One of the passive planar splitter are used to increase optical fibre channel. At the end of the collection a simplified examples of used measurements – optical time domain reflectometry and optical fibre transmission. Contains standard protocols or reflectogram. The conclusion of this thesis summarizes costs of FTTb (Fibre To The Building) model of optical metropolitan area network in Czech republic and future contribution for society.
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Deng, Tian. "LES combined with statistical models of spray formation closely to air-blast atomizer." Thesis, Ecully, Ecole centrale de Lyon, 2011. http://www.theses.fr/2011ECDL0037/document.
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Cette thèse présente une extension de l'approche stochastique de l'atomisation primaire de type air assisté près d'un injecteur. Cette approche avait déjà été introduite dans les publications de Gorokhovski et al. Dans le cadre de la simulation des grandes échelles, la zone d'atomisation primaire est simulée comme un corps immergé avec une structure stochastique. Ce dernier est défini par la simulation stochastique de la position et de la courbure de l'interface entre le liquide et le gaz. La simulation de la position de l'interface est basée sur l'hypothèse de symétrie d'échelle pour la fragmentation. La normale extérieure à l'interface est modélisée en supposant une relaxation statistique vers l'isotropie. Les statistiques de la force du corps immergé servent de conditions aux limites pour le champ de vitesse issu de la LES ainsi que pour la production des gouttes de l'atomisation primaire. Celles-ci sont ensuite transportées par une approche lagrangienne. Les collisions entre les gouttes dans la zone d'atomisation primaire sont prises en compte par analogie avec l'approche standard de la théorie cinétique des gaz. Une fermeture est proposée pour la température statistique des gouttelettes. Cette approche est validée par des comparaisons avec les mesures expérimentales de la thèse de Hong. Les résultats numériques pour la vitesse et de la taille des gouttes dans le spray à différentes distances du centre du jet et de l'orifice de la buse sont relativement proches des résultats expérimentaux. Différentes conditions d'entrée pour la vitesse sont testées et comparées aux résultats expérimentaux. Par ailleurs, le rôle spécifique de la zone de recirculation devant le dard liquide est soulignée par le battement du dard liquide et la production de gouttelettesThis thesis introduced an extension to stochastic approach for simulation of air-blast atomization closely to injector. This approach was previously proposed in publications of Gorokhovski with his PHD students. Our extension of this approach is as follows. In the framework of LES approach, the contribution of primary atomization zone is simulated as an immersed solid body with stochastic structure. The last one is defined by stochastic simulation of position-and-curvature of interface between the liquid and the gas. As it was done previously in this approach, the simulation of the interface position was based on statistical universalities of fragmentation under scaling symmetry. Additionally to this, we simulate the outwards normal to the interface, assuming its stochastic relaxation to isotropy along with propagation of spray in the down-stream direction. In this approach, the statistics of immersed body force plays role of boundary condition for LES velocity field, as well as for production of primary blobs, which are then tracked in the Lagrangian way. In this thesis, the inter-particle collisions in the primary atomisation zone are accounted also by analogy with standard kinetic approach for the ideal gas. The closure is proposed for the statistical temperature of droplets. The approach was assessed by comparison with measurements of Hong in his PHD. The results of computation showed that predicted statistics of the velocity and of the size in the spray at different distances from the center plane, at different distances from the nozzle orifice, at different inlet conditions (different gas velocity at constant gas-to-liquid momentum ratio, different gas-to-liquid momentum ratio) are relatively close to measurements. Besides, the specific role of recirculation zone in front of the liquid core was emphasized in the flapping of the liquid core and in the droplets production
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Sowards, Jeffrey William. "Development of a chromium-free consumable for joining stainless steel." Columbus, Ohio : Ohio State University, 2009. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1237845645.
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GARCíA, GUZMáN Jaime. "Modélisation du facteur de correction beta en indentation instrumentée." Thesis, Reims, 2017. http://www.theses.fr/2017REIMS043.
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Avec l’avènement des NEMS, MEMS, films minces et autres revêtements, la caractérisation des propriétés mécaniques à uneéchelle locale est primordiale. A cet effet, l’essai d’indentation instrumentée permet l’acquisition continue de la réponse (courbeforce – profondeur de pénétration) d’un matériau à la pénétration d’un indenteur de géométrie donnée. Le post-traitement d’unetelle courbe permet la détermination de propriétés telles que le module d’indentation ou la dureté. Cette analyse est basée surla théorie du contact élastique, qui suppose une géométrie axisymétrique parfaite de la pointe d’indentation, un comportementpurement élastique du matériau, et la non-prise en compte des déplacements radiaux dans la zone de contact. En pratique, ceshypothèses sont souvent mises en défaut : les indenteurs sont généralement des pyramides à 3 pans (Berkovich, Cube Corner)ou 4 pans (Vickers, Knoop) présentant un émoussement de la pointe, et le comportement mécanique des matériaux est souventcomplexe. La correction de la relation de Sneddon, utilisée dans la méthode d’Oliver et Pharr pour l’analyse des essais denanoindentation, est donc nécessaire. Dans le cadre de cette thèse, nous nous sommes intéressés à la détermination de ce facteurde correction, qui n’est pas une valeur universelle ni unique comme le préconisent certains auteurs. Il dépend notamment de lapression exercée par la pointe d’indentation et du matériau sollicité. Cette étude s’est faite sur la base de la détermination de laloi de comportement d’un des matériaux standards utilisés pour la calibration de l’essai de nanoindentation, la silice fondue.Ce matériau présente un comportement mécanique spécifique : sa déformation anélastique s’effectue par un mécanisme dedensification. Dans un premier temps, les paramètres de cette loi de comportement sont identifiés par une approche inversecombinant la simulation numérique 3D de l’essai d’indentation à l’optimisation de la fonction objectif au moyen d’unalgorithme génétique. Le facteur de correction est ensuite déterminé pour deux géométries de pointes et à différentes valeursdu rapport adimensionnel "profondeur de pénétration/rayon de pointe". La méthodologie proposée a été appliquée à ladétermination du module d’indentation d’un acier inoxWith the advent of NEMS, MEMS, thin films and other coatings, the characterization of local mechanical properties is achallenge. For this purpose, the instrumented indentation test allows for the continuous acquisition of the response (loadpenetration depth) of the material using an indenter of given geometry. The post-processing of such a curve allows thedetermination of the indentation modulus or the hardness of that material. This analysis relies on the elastic contact theory,which assumes an axisymmetric and perfect indenter, a purely elastic behaviour, and no radial displacements in the contactarea. In practice, those assumptions are defeated: indenters shapes are rather three-sided (Berkovich, Cube Corner) or foursided (Vickers, Knoop) pyramids, with blunted tips. Furthermore, mechanical behaviour is rather complex. The introductionof a correction factor in the Sneddon’s relationship, on which is based the Oliver and Pharr method for the analysis ofnanoindentation data is then necessary. Whithin the scope of this work, we aimed at determining this correction factor, whichhas not a unique nor a universal value, as recommended by some authors. It depends on the pressure distribution beneath theindenter and on the tested material. This study is based on the identification of the constitutive law of one of the referencespecimen used for calibration of the nanoindentation test, namely fused silica. The latter exhibits a specific mechanicalbehaviour, its anelastic deformation being achieved by a densification mechanism. In a first step we have determined the modelparameters by an inverse approach combining the 3D numerical simulation of the indentation test with the optimization of theobjective function using a genetic algorithm. The correction factor is then determined for two tip geometries and at severalpenetration depth over tip radius adimensional ratios. The proposed methodology was applied to the determination of theindentation modulus of an inox steel
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Body, Simon. "Physiopathologie du lymphome à cellules du manteau : de la mécanistique aux modèles précliniques." Thesis, Normandie, 2017. http://www.theses.fr/2017NORMC419/document.
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Le lymphome à cellules du manteau (LCM) est une hémopathie maligne B mature, appartenant à la famille des lymphomes non hodgkiniens. Le LCM est caractérisé par la translocation t(11;14)(q13;q32) qui provoque une expression aberrante de cycline D1. C’est une pathologie rare mais à haut risque de rechute, et qui reste le plus souvent incurable suite à l’apparition de clones chimiorésistants. L’acquisition de résistance est intimement liée aux interactions entre les cellules tumorales et leur microenvironnement. Afin de mimer de la manière la plus pertinente possible ces interactions, nous avons mis en place un modèle murin de xénogreffe en utilisant les lignées cellulaires de LCM JeKo1, REC1, Z138 et Granta-519 que nous avons modifiées afin qu’elles expriment un fluorophore (GFP ou m-cherry) et/ou le gène codant pour la luciférase. Après injection aux souris du substrat de la luciférase, la luciférine, nous sommes en mesure de suivre au cours du temps la progression tumorale. Nous pouvons également évaluer le degré d’infiltration tumorale dans la moelle osseuse, la rate, le cerveau et le sang après euthanasie des animaux, par des techniques de cytométrie en flux et d’immunocytochimie. Ce modèle nous a permis de montrer l’intérêt thérapeutique d’un inhibiteur de l’exportine 1 (XPO1) : le KPT 330 (ou selinexor) qui est capable de contenir cycline D1 uniquement au niveau nucléaire. Nous avons montré que la localisation subcellulaire de cycline D1, est retrouvée majoritairement cytoplasmique dans certaines lignées cellulaires de LCM (2/7) et chez un certain nombre de patients (6/42, 14%), et est associée à un fort potentiel d’invasion, de migration et à un phénotype agressif. Par ailleurs, grâce à ce modèle, nous avons pu objectiver le manque d’efficacité in vivo d’agonistes aux récepteurs aux œstrogènes de type β (ER β). Ces récepteurs, présents sur les lymphocytes B étaient supposés inhiber la prolifération cellulaire et provoquer la mort des cellules par apoptose. L’utilisation de deux agonistes des ER β, le diarylpropionitrile (DPN) et l’ERB-041 a montré une absence d’effet de ces molécules, lorsque les cellules tumorales sont au contact de leur microenvironnement. D’autre part, afin de mieux comprendre les mécanismes de résistance aux chimiothérapies, nous avons étudié la résistance de la lignée cellulaire REC-1 traitée par des agents génotoxiques. Nous avons montré que cette lignée présentait une anomalie de dégradation de cycline D1 associée à une activité diminuée du protéasome 26S. Enfin, nous avons montré dans des travaux préliminaires que la protéine fused in sarcoma (FUS) pourrait, lorsqu’elle est associée à cycline D1, être capable de réguler les voies de réparation des dommages à l’ADN. Des anomalies de ces voies induisent une grande instabilité génétique responsable de l’échappement des tumeurs aux traitements, le ciblage de FUS pourrait par conséquent présenter un intérêt thérapeutique.Pris dans leur ensemble, ces résultats permettent de renforcer ou d’infirmer l’intérêt de certaines cibles thérapeutiques dans l’espoir de pouvoir continuer à améliorer la prise en charge des patients. Ils fournissent également un outil pour l’évaluation de nouvelles molécules dans un modèle murin prenant en compte les interactions entre la cellule tumorale et son microenvironnementMantle cell lymphoma (MCL) is a mature malignant hemopathy, belonging to the non-Hodgkin's lymphoma family. The MCL is characterized by the translocation t(11;14)(q13;q32) which causes an aberrant expression of cyclin D1. It is a rare disease but at high risk of relapse, and it is most often incurable due to the appearance of chemoresistant clones. The acquisition of resistance is intimately linked to the interactions between the tumor cells and their microenvironment. In order to mimic, in the most relevant way, these interactions, we have implemented a mouse xenograft model using the MCL cell lines JeKo1, REC1, Z138 and Granta-519 which we have modified so that they express a fluorophore (GFP or m-cherry) and / or the gene encoding the luciferase. After injection to the mice of the luciferase substrate, luciferin, we are able to follow over time the tumor progression. We can also assess the degree of tumor infiltration in bone marrow, spleen, brain and blood after euthanasia of animals, by flow cytometry and immunocytochemistry. This model allowed us to show the therapeutic interest of an inhibitor of exportin 1 (XPO1): the KPT 330 (or selinexor) which is able to contain cyclin D1 only on the nuclear level. We have shown that the subcellular localization of cyclin D1 is mainly cytoplasmic in some LCM (2/7) cell lines and in a number of patients (6/42, 14%), and is associated with a high potential Invasion, migration and an aggressive phenotype. Moreover, thanks to this model, we have been able to objectify the in vivo lack of efficacy of agonists to β-type estrogen receptors (ER β). These receptors, present on B lymphocytes, were thought to inhibit cell proliferation and cause cell death by apoptosis. The use of two ER β agonists, diarylpropionitrile (DPN) and ERB-041 showed an absence of effect of these molecules, when the tumor cells are in contact with their microenvironment. On the other hand, in order to better understand the mechanisms of resistance to chemotherapies, we studied the resistance of the REC-1 cell line treated with genotoxic agents. We have shown that this line has an abnormality of cyclin D1 degradation associated with decreased activity of the 26S proteasome. Finally, we have shown in preliminary work that the fused in sarcoma protein (FUS) could, when associated with cyclin D1, be able to regulate the repair pathways of DNA damage. Abnormalities of these pathways induce a great genetic instability responsible for the escape of tumors to treatments, the targeting of FUS could therefore be of therapeutic interest.Taken as a whole, these results reinforce or invalidate the interest of certain therapeutic targets in the hope of continuing to improve the management of patients. They also provide a tool for evaluating new molecules in a murine model that takes into account the interactions between the tumor cell and its microenvironment
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Zhang, Yang. "Etude des conséquences mécaniques de la transformation de phase dans les réfractaires électrofondus à très haute teneur en zircone." Thesis, Paris Sciences et Lettres (ComUE), 2017. http://www.theses.fr/2017PSLEM035/document.
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Les réfractaires électrofondus, qui constituent l’objet de ce travail, appartiennent au système alumine-zircone-silice. Ils sont obtenus par coulée dans des moules à des températures supérieures à 2000°C, rendant très difficile toute instrumentation. De nombreux phénomènes intrinsèques au matériau interviennent lors du refroidissement qui suit la coulée. Parmi ces derniers, cette recherche a essentiellement porté sur la transformation de phase (de tétragonale à monoclinique) de la zircone et aux phénomènes associés (gonflement, plasticité,…).A partir d’essais mécaniques à haute température réalisés en laboratoire, les lois de comportements thermiques et mécaniques ont été caractérisées et modélisées en cours de transformation de la zircone. La plasticité à très bas seuil de contrainte observée a, en particulier, été décrite par une vitesse de déformation dérivée du modèle de Leblond, une fonction de rendement de type Cam-clay sans consolidation et une fonction de rendement définissant l’avancement de la transformation en fonction de la température. Après implémentation dans un code de calcul par éléments finis et validation par confrontation avec des résultats d’essais sous contraintes multiaxiales, ce modèle a été assemblé aux autres composantes du comportement mécanique (fluage, élasticité,…), pour décrire l’ensemble des phénomènes thermomécaniques observés lors du refroidissement.Parallèlement, des coulées de blocs en laboratoire, instrumentées par des thermocouples et des capteurs d’émission acoustique, ont permis de reconstruire par simulation numérique l’évolution du champ de température à l’intérieur de la dalle au cours du refroidissement. L’enthalpie de solidification et celle associée à la transformation de phase, préalablement quantifiée par ATD, ont été prises en compte. L’application du modèle mécanique complet, associant toutes les composantes du comportement, a permis de calculer l’évolution du champ de contraintes généré par les gradients thermiques en fonction du temps et, en particulier, de mettre en évidence le rôle essentiel joué par la transformation de phase sur la relaxation des contraintesFused-cast refractories, which are concerned by this work, belong to the alumina-zirconia-silica system. They are obtained by casting in molds at temperatures higher than 2000°C, that make very difficult any instrumentation. Many phenomena intrinsic to the material occur during cooling-down after casting. Among these latter, this research essentially focused on the phase transformation (from tetragonal to monoclinic) of zirconia and the associated phenomena (swelling, plasticity,...).From high temperature mechanical tests performed in laboratory, the thermal and mechanical behavior laws were characterized and modeled during the zirconia transformation. Plasticity at very low stress threshold was observed. A Leblond type model has been extended by introducing a Cam-clay yield function without consolidation. In this model, the progress of the transformation is controlled by the evolution of the temperature. This model was complemented by other components of the mechanical behavior (creep, elasticity, ...). It has been validated by experimental tests under multiaxial loadings that replicate the main thermomechanical phenomena observed during cooling.In parallel, blocks casted in laboratory conditions, instrumented with thermocouples and acoustic emission sensors, allowed a numerical simulation of the change in temperature field within the block during cooling-down. This simulation took into account the solidification enthalpy and the enthalpy associated to the phase transformation, previously quantified by DTA. The implementation of the complete mechanical model integrating all the behavior components led to a calculation of the stress field changes generated by thermal gradients as a function of time and, in particular, to highlight the essential role played by the phase transformation on stress relaxation
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Naumann, Marcel Günter [Verfasser], Andreas [Gutachter] Hermann, and Min Ae [Gutachter] Lee-Kirsch. "Development of a human in-vitro pathophysiological model of FUS-ALS based on the induced pluripotent stem-cell technique and translation to patient phenotypes / Marcel Günter Naumann ; Gutachter: Andreas Hermann, Min Ae Lee-Kirsch." Dresden : Technische Universität Dresden, 2021. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa2-760595.
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Sarotte, Camille. "Improvement of monitoring and reconfiguration processes for liquid propellant rocket engine." Thesis, Université Paris-Saclay (ComUE), 2019. http://www.theses.fr/2019SACLS348/document.
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La surveillance et l'amélioration des modes de fonctionnement des systèmes propulsifs des lanceurs représentent des défis majeurs de l'industrie aérospatiale. En effet, une défaillance ou un dysfonctionnement du système propulsif peut avoir un impact significatif pour les clients institutionnels ou privés et entraîner des catastrophes environnementales ou humaines. Des systèmes de gestion de la santé (HMS) pour les moteurs fusée à ergols liquides (LPREs), ont été mis au point pour tenir compte des défis actuels en abordant les questions de sureté et de fiabilité. Leur objectif initial est de détecter les pannes ou dysfonctionnements, de les localiser et de prendre une décision à l’aide de Redlines et de systèmes experts. Cependant, ces méthodes peuvent induire de fausses alarmes ou des non-détections de pannes pouvant être critiques pour la sécurité et la fiabilité des opérations. Ainsi, les travaux actuels visent à éliminer certaines pannes critiques, mais aussi diminuer les arrêts intempestifs. Les données disponibles étant limitées, des méthodes à base de modèles sont essentiellement utilisées. La première tâche consiste à détecter les défaillances de composants et/ou d'instruments à l'aide de méthodes de détection et de localisation de fautes (FDI). Si la faute est considérée comme mineure, des actions de « non-arrêt » sont définies pour maintenir les performances de l'ensemble du système à un niveau proche de celles souhaitées et préserver les conditions de stabilité. Il est donc nécessaire d’effectuer une reconfiguration robuste (incertitudes, perturbations inconnues) du moteur. Les saturations en entrée doivent également être prises en compte dans la conception de la loi de commande, les signaux de commande étant limités en raison des caractéristiques ou performances des actionneurs physiques. Les trois objectifs de cette thèse sont donc : la modélisation des différents sous-systèmes principaux d’un LPRE, le développement d’algorithmes de FDI sur la base des modèles établis et la définition d’un système de reconfiguration du moteur en temps réel pour compenser certains types de pannes. Le système de FDI et Reconfiguration (FDIR) développé sur la base de ces trois objectifs a ensuite été validé à l’aide de simulations avec CARINS (CNES) et du banc d’essai MASCOTTE (CNES/ONERA)Monitoring and improving the operating modes of launcher propulsion systems are major challenges in the aerospace industry. A failure or malfunction of the propulsion system can have a significant impact for institutional or private customers and results in environmental or human catastrophes. Health Management Systems (HMS) for liquid propellant rocket engines (LPREs), have been developed to take into account the current challenges by addressing safety and reliability issues. Their objective was initially to detect failures or malfunctions, isolate them and take a decision using Redlines and Expert Systems. However, those methods can induce false alarms or undetected failures that can be critical for the operation safety and reliability. Hence, current works aim at eliminating some catastrophic failures but also to mitigate benign shutdowns to non-shutdown actions. Since databases are not always sufficient to use efficiently data-based analysis methods, model-based methods are essentially used. The first task is to detect component and / or instrument failures with Fault Detection and Isolation (FDI) approaches. If the failure is minor, non-shutdown actions must be defined to maintain the overall system current performances close to the desirable ones and preserve stability conditions. For this reason, it is required to perform a robust (uncertainties, unknown disturbances) reconfiguration of the engine. Input saturation should also be considered in the control law design since unlimited control signals are not available due to physical actuators characteristics or performances. The three objectives of this thesis are therefore: the modeling of the different main subsystems of a LPRE, the development of FDI algorithms from the previously developed models and the definition of a real-time engine reconfiguration system to compensate for certain types of failures. The developed FDI and Reconfiguration (FDIR) scheme based on those three objectives has then been validated with the help of simulations with CARINS (CNES) and the MASCOTTE test bench (CNES/ONERA)
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LARAIA, LILIAN R. "Fatores alavancadores e desafiadores no uso de mapas de rotas tecnológicas no contexto de instituições de pesquisas públicas. Um estudo de caso." reponame:Repositório Institucional do IPEN, 2015. http://repositorio.ipen.br:8080/xmlui/handle/123456789/23890.
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Submitted by Claudinei Pracidelli (cpracide@ipen.br) on 2015-08-12T12:22:44Z
No. of bitstreams: 0Made available in DSpace on 2015-08-12T12:22:44Z (GMT). No. of bitstreams: 0
Dissertação (Mestrado em Tecnologia Nuclear)
IPEN/D
Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP
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Onyeako, Isidore. "Resolution-aware Slicing of CAD Data for 3D Printing." Thesis, Université d'Ottawa / University of Ottawa, 2016. http://hdl.handle.net/10393/34303.
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3D printing applications have achieved increased success as an additive manufacturing (AM) process. Micro-structure of mechanical/biological materials present design challenges owing to the resolution of 3D printers and material properties/composition. Biological materials are complex in structure and composition. Efforts have been made by 3D printer manufacturers to provide materials with varying physical, mechanical and chemical properties, to handle simple to complex applications. As 3D printing is finding more medical applications, we expect future uses in areas such as hip replacement - where smoothness of the femoral head is important to reduce friction that can cause a lot of pain to a patient. The issue of print resolution plays a vital role due to staircase effect. In some practical applications where 3D printing is intended to produce replacement parts with joints with movable parts, low resolution printing results in fused joints when the joint clearance is intended to be very small. Various 3D printers are capable of print resolutions of up to 600dpi (dots per inch) as quoted in their datasheets. Although the above quoted level of detail can satisfy the micro-structure needs of a large set of biological/mechanical models under investigation, it is important to include the ability of a 3D slicing application to check that the printer can properly produce the feature with the smallest detail in a model. A way to perform this check would be the physical measurement of printed parts and comparison to expected results. Our work includes a method for using ray casting to detect features in the 3D CAD models whose sizes are below the minimum allowed by the printer resolution. The resolution validation method is tested using a few simple and complex 3D models. Our proposed method serves two purposes: (a) to assist CAD model designers in developing models whose printability is assured. This is achieved by warning or preventing the designer when they are about to perform shape operations that will lead to regions/features with sizes lower than that of the printer resolution; (b) to validate slicing outputs before generation of G-Codes to identify regions/features with sizes lower than the printer resolution.
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Potier, Luc. "Large Eddy Simulation of the combustion and heat transfer in sub-critical rocket engines." Thesis, Toulouse, INPT, 2018. http://www.theses.fr/2018INPT0043/document.
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La combustion cryogénique dans les moteurs de fusée dits à propulsion liquide utilise généralement un couple d'ergols, le plus couramment composé d'hydrogène/oxygène (H2/O2). Privilégiée pour le fort pouvoir calorifique du dihydrogène, cette combustion à haute pression, induit des températures de fonctionnement très élevées et nécessite l'intégration d'un système de refroidissement. La prédiction des flux thermiques aux parois est donc un élément essentiel de la conception d'une chambre de combustion de moteur fusée. Ces flux sont le résultat d'écoulements fortement turbulents, compressibles, avec une cinétique chimique violente induisant de forts gradients d'espèces et de température. La simulation de ces phénomènes nécessite des approches spécifiques telles que la Simulation aux Grandes Echelles (SGE) qui réalise un très bon compromis entre précision et coût de calcul. Cette thèse a ainsi pour objectif la simulation par SGE des transferts de chaleur aux parois dans les chambres de combustion de moteurs fusée opérant en régime sous-critique. Le régime sous-critique implique un état liquide pour un des ergols, dont il faut traiter l'injection et l'atomisation. Dans un premier temps ce travail s'intéresse à plusieurs éléments de modélisation nécessaire pour réaliser les simulations visées. Le comportement des flammes H2/O2 est décrit par un schéma cinétique réduit et validé sur des configurations académiques. La prédictivité de ce schéma est évaluée sur une large gamme de fonctionnement dans des conditions représentatives des moteurs fusée. La simulation de l'injection de l'oxygène liquide (LOx) est un autre point critique qui nécessite de décrire l'atomisation et la phase dispersée ainsi que son couplage avec la phase gazeuse. La déstabilisation et l'atomisation primaire du jet liquide, trop complexe à simuler en SGE 3D, sont omises ici pour injecter directement un spray paramétré grâce à des corrélations empiriques. Enfin, la prédiction des flux thermiques utilise un modèle de loi de paroi spécifiquement dédiée aux écoulements à fort gradient de température. Cette loi de paroi est validée sur des configurations de canaux turbulents par comparaison avec des simulations avec résolution directe de la couche limite. La méthodologie basée sur les modèles développés est ensuite employée pour la simulation d'une chambre de combustion représentative du fonctionnement des moteurs cryogéniques. Il s'agit de la configuration CONFORTH testée sur le banc MASCOTTE (ONERA) et pour laquelle des mesures de température de paroi et de flux thermiques sont disponibles. Les résultats des SGE montrent un bon accord avec l'expérience et démontrent la capacité de la SGE à prédire les flux thermiques dans une chambre de combustion de moteur fusée. Enfin, dans un dernier chapitre ce travail s'intéresse à une méthode d'augmentation des transferts thermiques via une expérience de JAXA utilisant des parois rainurées dans la direction axiale. Par comparaison avec une chambre à parois lisses, les résultats démontrent la bonne prédiction par la SGE de l'augmentation du flux de chaleur grâce aux rainures et confirment la validité de la méthode développée pour des géométries de paroi complexesCombustion in cryogenic engines is a complex phenomenon, involving either liquid or supercritical fluids at high pressure, strong and fast oxidation chemistry, and high turbulence intensity. Due to extreme operating conditions, a particularly critical issue in rocket engine is wall heat transfer which requires efficient cooling of the combustor walls. The concern goes beyond material resistance: heat fluxes extracted through the chamber walls may be reused to reduce ergol mass or increase the power of the engine. In expander-type engine cycle, this is even more important since the heat extracted by the cooling system is used to drive the turbo-pumps that feed the chamber in fuel and oxidizer. The design of rocket combustors requires therefore an accurate prediction of wall heat flux. To understand and control the physics at play in such combustor, the Large Eddy Simulation (LES) approach is an efficient and reliable numerical tool. In this thesis work, the objective is to predict wall fluxes in a subcritical rocket engine configuration by means of LES. In such condition, ergols may be in their liquid state and it is necessary to model liquid jet atomization, dispersion and evaporation.The physics that have to be treated in such engine are: highly turbulent reactive flow, liquid jet atomization, fast and strong kinetic chemistry and finally important wall heat fluxes. This work first focuses on several modeling aspects that are needed to perform the target simulations. H2/O2 flames are driven by a very fast chemistry, modeled with a reduced mechanism validated on academic configurations for a large range of operating conditions in laminar pre- mixed and non-premixed flames. To form the spray issued from the atomization of liquid oxygen (LOx) an injection model is proposed based on empirical correlations. Finally, a wall law is employed to recover the wall fluxes without resolving directly the boundary layer. It has been specifically developed for important temperature gradients at the wall and validated on turbulent channel configurations by comparison with wall resolved LES. The above models are then applied first to the simulation of the CONFORTH sub-scale thrust chamber. This configuration studied on the MASCOTTE test facility (ONERA) has been measured in terms of wall temperature and heat flux. The LES shows a good agreement compared to experiment, which demonstrates the capability of LES to predict heat fluxes in rocket combustion chambers. Finally, the JAXA experiment conducted at JAXA/Kakuda space center to observe heat transfer enhancement brought by longitudinal ribs along the chamber inner walls is also simulated with the same methodology. Temperature and wall fluxes measured with smooth walls and ribbed walls are well recovered by LES. This confirms that the LES methodology proposed in this work is able to handle wall fluxes in complex geometries for rocket operating conditions
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Laurent, Charlelie. "Low-order modeling and high-fidelity simulations for the prediction of combustion instabilities in liquid rocket engines and gas turbines." Thesis, Toulouse, INPT, 2020. http://www.theses.fr/2020INPT0038.
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Au cours des dernières décennies, les instabilités de combustion ont constitué un important défi pour de nombreux projets industriels, en particulier dans la conception de moteurs-fusées à ergols liquide et de turbines à gaz. L'atténuation de leurs effets nécessite une solide compréhension scientifique de l'interaction complexe entre la dynamique de flamme et les ondes acoustiques qu'elles impliquent. Au cours de cette thèse, plusieurs directions ont été explorées pour fournir une meilleure compréhension de la dynamique des flammes dans les moteurs-fusées cryogéniques, ainsi que des méthodes numériques plus efficaces et robustes pour la prédiction des instabilités thermoacoustiques dans les chambres de combustion à géométries complexes. La première facette de ce travail a consisté en la résolution de modes thermoacoustiques dans les chambres de combustion complexes comportant à injecteurs multiples, une tâche qui nécessite souvent des simplifications pour être abordable en termes de coût de calcul. Ces hypothèses physiques nécessaires ont conduit à la popularité croissante des modèles bas-ordre acoustiques, parmi lesquels ceux utilisant l'expansion de Galerkin ont démontré une efficacité prometteuse tout en conservant une précision satisfaisante. Ceux-ci sont cependant limités à des géométries simples qui n'intègrent pas les caractéristiques complexes des systèmes industriels. Une grande partie de ce travail a donc consisté tout d'abord à identifier clairement les limitations mathématiques de l'expansion classique de Galerkin, puis à concevoir un nouveau type d'expansion modale, appelé expansion sur frame, qui ne souffre pas des mêmes restrictions. En particulier, l'expansion sur frame est capable de représenter avec précision le champ de vitesse acoustique près des parois de la chambre de combustion autres que des murs rigides, une capacité cruciale qui manque à la méthode Galerkin. Dans ce travail, le concept d'expansion modale de surface a également été introduit pour modéliser des frontières topologiquement complexes, comme les plaques multi-perforées rencontrées dans les turbines à gaz. Ces nouvelles méthodes numériques ont été combinées avec le formalisme state-space pour construire des réseaux acoustiques de systèmes complexes. Le modèle obtenu a été implémenté dans le code STORM (State-space Thermoacoustic low-ORder Model), qui permet la modélisation bas-ordre des instabilités thermoacoustiques dans des géométries arbitrairement complexes. Le deuxième ingrédient de la prédiction des instabilités thermoacoustiques est la modélisation de la dynamique de flamme. Ce travail a traité de ce point, dans le cas spécifique d'une flamme-jet cryogénique caractéristique d'un moteur-fusée à ergols liquides. Les phénomènes contrôlant la dynamique de flamme ont été identifiés grâce à des Simulations aux Grandes Échelles (SGE) du banc d'essai expérimental Mascotte, où les deux réactifs (CH4 et O2) sont injectés dans des conditions transcritiques. Une première simulation donne un aperçu détaillé de la dynamique intrinsèque de la flamme. Plusieurs SGE avec modulation harmonique de l'injection de carburant, à différentes fréquences et amplitudes, ont été effectués afin d'évaluer la réponse de la flamme aux oscillations acoustiques et de calculer une Fonction de Transfert de Flamme (FTF). La réponse non-linéaire de la flamme, notamment les interactions entre les oscillations intrinsèques et forcées, a également été étudiée. Enfin, la stabilisation de cette flamme dans la région proche de l'injecteur, qui est d'une importance primordiale sur la dynamique globale de la flamme, a été étudiée grâce à une simulation directe multi-physique, où un problème couplé de transfert de chaleur est résolu au niveau de la lèvre de l'injecteurOver the last decades, combustion instabilities have been a major concern for a number of industrial projects, especially in the design of Liquid Rocket Engines (LREs) and gas turbines. Mitigating their effects requires a solid scientific understanding of the intricate interplay between flame dynamics and acoustic waves that they involve. During this PhD work, several directions were explored to provide a better comprehension of flame dynamics in cryogenic rocket engines, as well as more efficient and robust numerical methods for the prediction of thermoacoustic instabilities in complex combustors. The first facet of this work consisted in the resolution of unstable thermoacoustic modes in complex multi-injectors combustors, a task that often requires a number of simplifications to be computationally affordable. These necessary physics-based assumptions led to the growing popularity of acoustic Low-Order Models (LOMs), among which Galerkin expansion LOMs have displayed a promising efficiency while retaining a satisfactory accuracy. Those are however limited to simple geometries that do not incorporate the complex features of industrial systems. A major part of this work therefore consisted first in clearly identifying the mathematical limitations of the classical Galerkin expansion, and then in designing a novel type of modal expansion, named a frame expansion, that does not suffer from the same restrictions. In particular, the frame expansion is able to accurately represent the acoustic velocity field, near non-rigid-wall boundaries of the combustor, a crucial ability that the Galerkin method lacks. In this work, the concept of surface modal expansion is also introduced to model topologically complex boundaries, such as multi-perforated liners encountered in gas turbines. These novel numerical methods were combined with the state-space formalism to build acoustic networks of complex systems. The resulting LOM framework was implemented in the code STORM (State-space Thermoacoustic low-ORder Model), which enables the low-order modeling of thermoacoustic instabilities in arbitrarily complex geometries. The second ingredient in the prediction of thermoacoustic instabilities is the flame dynamics modeling. This work dealt with this problem, in the specific case of a cryogenic coaxial jet-flame characteristic of a LRE. Flame dynamics driving phenomena were identified thanks to three-dimensional Large Eddy Simulations (LES) of the Mascotte experimental test rig where both reactants (CH4 and O2) are injected in transcritical conditions. A first simulation provides a detailed insight into the flame intrinsic dynamics. Several LES with harmonic modulation of the fuel inflow at various frequencies and amplitudes were performed in order to evaluate the flame response to acoustic oscillations and compute a Flame Transfer Function (FTF). The flame nonlinear response, including interactions between intrinsic and forced oscillations, were also investigated. Finally, the stabilization of this flame in the near-injector region, which is of primary importance on the overall flame dynamics, was investigated thanks to muulti-physics two-dimensional Direct Numerical Simulations (DNS), where a conjugate heat transfer problem is resolved at the injector lip
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Cocheteau, Natacha. "Caractérisation et modélisation d'une adhérence moléculaire renforcée." Thesis, Aix-Marseille, 2014. http://www.theses.fr/2014AIXM4700/document.
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Le collage par adhérence moléculaire est un collage basé sur la mise en contact de deux surfaces sans l'utilisation de colle ou matériaux additionnels. Ce procédé de collage est utilisé dans de nombreuses applications, notamment dans les domaines de l'optique terrestre et spatiale. Bien qu'un prototype ait déjà passé avec succès l'environnement spatial - où les contraintes d'utilisations sont différentes de celles rencontrées sur Terre - la spatialisation de cette technologie nécessite une caractérisation plus fine du procédé ainsi qu'une amélioration de la tenue mécanique des interfaces adhérées afin de valider les normes de l'Agence spatiale Européenne. Pour répondre à cette problématique de spatialisation de la technologie, des essais mécaniques ainsi que des analyses chimiques ont été réalisés dans le but d'étudier l'influence de certains paramètres du procédé ) sur la tenue mécanique et l'énergie de collage. Ces essais ont également été réalisés afin de comparer les deux matériaux étudiés : le verre de silice et le Zérodur vis-à-vis de l'adhésion. A l'issue de ces essais, les paramètres à appliquer permettant de doubler la tenue mécanique des interfaces adhérées ont été déterminés. Parallèlement, une loi phénoménologique reliant l'énergie de collage aux précédents paramètres du procédé a été développée ainsi qu'un modèle macroscopique visant à décrire l'intensité d'adhésion. Ces deux modèles une fois couplés permettent de modéliser le comportement normal de l'interface en fonction des paramètres du procédé. Enfin, ces deux lois sont implémentées dans un code éléments finis afin de simuler la propagation de la fissure lors de l'essai de clivage au coinDirect bonding consists in joining two surfaces without the use of any adhesive or additional material. This process is used in several applications, particularly in terrestrial and spatial optics. Although a prototype passed with success spatial environment - where constraints involved are very different from those encountered on Earth - this technology requires a more detailed characterization and an improvement of the mechanical strength of bonded interfaces in order to validate the European Space Agency standards. To address this issue, mechanical tests (double shear tests, cleavage tests and wedge tests) and chemical analysis (wetting tests and XPS spectroscopy) were performed in order to study the influence of some process parameters (roughness, relative air humidity during room temperature bonding, the annealing temperature and time) on the mechanical strength and the bonding energy. These tests compared the two materials used: fused silica glass and Zerodur glass. As a result of these tests, optimal parameters doubling the mechanical strength were also obtained. In the same time, a phenomenological law relating the bonding energy to the previous parameters is developed as well as a macroscopic model to describe the adhesion intensity. Both models when coupled describe the normal behavior of the bonded interface depending on the process parameters. Then, the both laws are implemented in a finite elements model in order to simulate the crack propagation during the wedge test
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Ondráček, Michal. "Vývoj vysokopevnostních betonů definovaných vlastností s využitím druhotných surovin." Doctoral thesis, Vysoké učení technické v Brně. Fakulta stavební, 2013. http://www.nusl.cz/ntk/nusl-233787.
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Civil engineering development is connected with the application of new construction methods and the development of new building materials. Concrete, as one of the basic building materials, is part of this development. A major turning point in the development of concrete and its properties occurred with the use of new, more efficient plasticizing additives. This allowed to produce concrete with lower water cement ratio, while increasing the strength of concrete. Gradually, the compressive strength of concrete boundary has moved by several levels, when there are currently commonly used concrete with strength of about 100 N/mm2 and with the special methods of concrete production strength range from 250 to 300 N/mm2. A negative aspect of the development of (ultra) high-strength concrete is their energy and economic demands. A characteristic feature of high-strength concrete is a high content of cement and very fine admixtures, especially silica fume. One way to improve the economics of these types of concrete is the application of cheaper admixture based on industrial waste. The content of this work is the observation and description of the properties of high-strength concrete and reactive powder concrete, in which the admixtures were based on industrial waste were applied. Part of this work is the comparison of economic parameters for individual types of concrete.
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Di, Pace Sibilla. "Vers l’observation du bruit quantique de la pression de radiation dans un interféromètre suspendu : l’expérience QuRaG." Thesis, Nice, 2014. http://www.theses.fr/2014NICE4108/document.
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L'existence des ondes gravitationnelles (OG) est l'une des prédictions les plus intéressantes de la théorie de la Relativité Générale d'Einstein. La découverte expérimentale des OG serait donc un test important de la théorie elle-même et permettra d'ouvrir une nouvelle fenêtre d'observation en particulier dans les régions de l'Univers inaccessible à l'observation électromagnétique. Les détecteurs interférométriques, comme Virgo, sont les dispositifs les plus prometteurs pour la détection d’OG. Actuellement, leur sensibilité n'est pas encore suffisante pour avoir un taux d'observation de quelques événements/an. Un intense programme expérimental pour l’améliorer est en cours. Particulièrement, les prochaines générations de détecteurs d'OG, aux basses fréquences, seront limitées par l'effet de la pression de radiation (PR) sur les miroirs suspendus. Ce phénomène, pas encore observé expérimentalement, est l'objet d'un champ de recherche très actif. Mon travail ici présenté vise à la construction d'un détecteur pour l'étude des effets quantiques de la PR dans les détecteurs d’OG: QuRaG. Il sera constitué d'un interféromètre de Michelson suspendu dont chaque bras sera une cavité Fabry-Pérot de très haute finesse, dans laquelle seulement le miroir de fond sera suspendu et sensible au bruit quantique de la PR. Durant ma thèse j'ai participé activement au R&D de tous les sous-systèmes de QuRaG. Par conséquent, le travail que j'ai fait porte sur divers aspects du projet dont les problématiques appartiennent à différents domaines de la physique. Mon travail présenté ici démontre que QuRaG sera réalisable et qu’il observera le bruit de la PR dans la bande de fréquences attendueThe existence of gravitational waves (GW) is one of the most interesting predictions of the theory of general relativity of Einstein. The experimental discovery of GW would be an important test of the theory itself. In addition, the detection of GW will open a new window of observation especially in those regions of the Universe inaccessible to electromagnetic observations. Interferometers, as Virgo are the most promising devices for the detection of GW. Currently, the sensitivity of these detectors is not yet sufficient to have a detection rate of few events/year. Therefore, an intense experimental program to improve the sensitivity is underway. Specifically, the sensitivity of the next generations of GW detectors, at low frequencies, will be limited by the effect of the radiation pressure (RP) on the suspended mirrors. This phenomenon not yet observed experimentally in the ground based GW detectors band, is currently the subject of a very active research field. My work presented here aims at building a detector for studying quantum effects of RP in GW detectors: the QuRaG experiment. It will consist of a suspended Michelson interferometer where each arm will be a high finesse Fabry-Pérot cavity, in which only the end mirror will be further suspended and then sensitive to the RP noise. During my PhD I have actively participated to the R&D of all QuRaG subsystems. Therefore, the work that I have done deals with various aspects of the project whose related problems belong to different domains of physics. My work described in this manuscript demonstrates that QuRaG is realizable and that it will be able to observe the RP noise in the expected frequency range
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Fenollosa, Artés Felip. "Contribució a l'estudi de la impressió 3D per a la fabricació de models per facilitar l'assaig d'operacions quirúrgiques de tumors." Doctoral thesis, Universitat Politècnica de Catalunya, 2019. http://hdl.handle.net/10803/667421.
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La present tesi doctoral s’ha centrat en el repte d’aconseguir, mitjançant Fabricació Additiva (FA), models per a assaig quirúrgic, sota la premissa que els equips per fer-los haurien de ser accessibles a l’àmbit hospitalari. L’objectiu és facilitar l’extensió de l’ús dels prototips com a eina de preparació d’operacions quirúrgiques, transformant la pràctica mèdica actual de la mateixa manera que en el seu moment ho van fer tecnologies com les que van facilitar l’ús de radiografies. El motiu d’utilitzar FA, en lloc de tecnologies més tradicionals, és la seva capacitat de materialitzar de forma directa les dades digitals obtingudes de l’anatomia del pacient mitjançant sistemes d’escanejat tridimensional, fent possible l’obtenció de models personalitzats. Els resultats es centren en la generació de nou coneixement sobre com aconseguir equipaments d’impressió 3D multimaterials accessibles que permetin l’obtenció de models mimètics respecte als teixits vius. Per facilitar aquesta buscada extensió de la tecnologia, s’ha focalitzat en les tecnologies de codi obert com la Fabricació per Filament Fos (FFF) i similars basades en líquids catalitzables. La recerca s’alinea dins l’activitat de desenvolupament de la FA al CIM UPC, i en aquest àmbit concret amb la col·laboració amb l’Hospital Sant Joan de Déu de Barcelona (HSJD). El primer bloc de la tesi inclou la descripció de l’estat de l’art, detallant les tecnologies existents i la seva aplicació a l’entorn mèdic. S’han establert per primer cop unes bases de caracterització dels teixits vius -sobretot tous- per donar suport a la selecció de materials que els puguin mimetitzar en un procés de FA, a efectes de millorar l’experiència d’assaig dels cirurgians. El caràcter rígid dels materials majoritàriament usats en impressió 3D els fa poc útils per simular tumors i altres referències anatòmiques. De forma successiva, es tracten paràmetres com la densitat, la viscoelasticitat, la caracterització dels materials tous a la indústria, l’estudi del mòdul elàstic de teixits tous i vasos, la duresa d’aquests, i requeriments com l’esterilització dels models. El segon bloc comença explorant la impressió 3D mitjançant FFF. Es classifiquen les variants del procés des del punt de vista de la multimaterialitat, essencial per fer models d’assaig quirúrgic, diferenciant entre solucions multibroquet i de barreja al capçal. S’ha inclòs l’estudi de materials (filaments i líquids) que serien més útils per mimetitzar teixits tous. Es constata com en els líquids, en comparació amb els filaments, la complexitat del treball en processos de FA és més elevada, i es determinen formes d’imprimir materials molt tous. Per acabar, s’exposen sis casos reals de col·laboració amb l’HJSD, una selecció d’aquells en els que el doctorand ha intervingut en els darrers anys. L’origen es troba en la dificultat de l’abordatge d’operacions de resecció de tumors infantils com el neuroblastoma, i a la iniciativa del Dr. Lucas Krauel. Finalment, el Bloc 3 té per objecte explorar nombrosos conceptes (fins a 8), activitat completada al llarg dels darrers cinc anys amb el suport dels mitjans del CIM UPC i de l’activitat associada a treballs finals d’estudis d’estudiants de la UPC, arribant-se a materialitzar equipaments experimentals per validar-los. La recerca ampla i sistemàtica al respecte fa que s’estigui més a prop de disposar d’una solució d’impressió 3D multimaterial de sobretaula. Es determina que la millor via de progrés és la de disposar d’una pluralitat de capçals independents a fi de capacitar la impressora 3D per integrar diversos conceptes estudiats, materialitzant-se una possible solució. Cloent la tesi, es planteja com seria un equipament d’impressió 3D per a models d’assaig quirúrgic, a fi de servir de base per a futurs desenvolupaments.La presente tesis doctoral se ha centrado en el reto de conseguir, mediante Fabricación Aditiva (FA), modelos para ensayo quirúrgico, bajo la premisa que los equipos para obtenerlos tendrían que ser accesibles al ámbito hospitalario. El objetivo es facilitar la extensión del uso de modelos como herramienta de preparación de operaciones quirúrgicas, transformando la práctica médica actual de la misma manera que, en su momento, lo hicieron tecnologías como las que facilitaron el uso de radiografías. El motivo de utilizar FA, en lugar de tecnologías más tradicionales, es su capacidad de materializar de forma directa los datos digitales obtenidos de la anatomía del paciente mediante sistemas de escaneado tridimensional, haciendo posible la obtención de modelos personalizados. Los resultados se centran en la generación de nuevo conocimiento para conseguir equipamientos de impresión 3D multimateriales accesibles que permitan la obtención de modelos miméticos respecto a los tejidos vivos. Para facilitar la buscada extensión de la tecnología, se ha focalizado en las tecnologías de código abierto como la Fabricación por Hilo Fundido (FFF) y similares basadas en líquidos catalizables. Esta investigación se alinea dentro de la actividad de desarrollo de la FA en el CIM UPC, y en este ámbito concreto con la colaboración con el Hospital Sant Joan de Déu de Barcelona (HSJD). El primer bloque de la tesis incluye la descripción del estado del arte, detallando las tecnologías existentes y su aplicación al entorno médico. Se han establecido por primera vez unas bases de caracterización de los tejidos vivos – principalmente blandos – para dar apoyo a la selección de materiales que los puedan mimetizar en un proceso de FA, a efectos de mejorar la experiencia de ensayo de los cirujanos. El carácter rígido de los materiales mayoritariamente usados en impresión 3D los hace poco útiles para simular tumores y otras referencias anatómicas. De forma sucesiva, se tratan parámetros como la densidad, la viscoelasticidad, la caracterización de materiales blandos en la industria, el estudio del módulo elástico de tejidos blandos y vasos, la dureza de los mismos, y requerimientos como la esterilización de los modelos. El segundo bloque empieza explorando la impresión 3D mediante FFF. Se clasifican las variantes del proceso desde el punto de vista de la multimaterialidad, esencial para hacer modelos de ensayo quirúrgico, diferenciando entre soluciones multiboquilla y de mezcla en el cabezal. Se ha incluido el estudio de materiales (filamentos y líquidos) que serían más útiles para mimetizar tejidos blandos. Se constata como en los líquidos, en comparación con los filamentos, la complejidad del trabajo en procesos de FA es más elevada, y se determinan formas de imprimir materiales muy blandos. Para acabar, se exponen seis casos reales de colaboración con el HJSD, una selección de aquellos en los que el doctorando ha intervenido en los últimos años. El origen se encuentra en la dificultad del abordaje de operaciones de resección de tumores infantiles como el neuroblastoma, y en la iniciativa del Dr. Lucas Krauel. Finalmente, el Bloque 3 desarrolla numerosos conceptos (hasta 8), actividad completada a lo largo de los últimos cinco años con el apoyo de los medios del CIM UPC y de la actividad asociada a trabajos finales de estudios de estudiantes de la UPC, llegándose a materializar equipamientos experimentales para validarlos. La investigación amplia y sistemática al respecto hace que se esté más cerca de disponer de una solución de impresión 3D multimaterial de sobremesa. Se determina que la mejor vía de progreso es la de disponer de una pluralidad de cabezales independientes, a fin de capacitar la impresora 3D para integrar diversos conceptos estudiados, materializándose una posible solución. Para cerrar la tesis, se plantea cómo sería un equipamiento de impresión 3D para modelos de ensayo quirúrgico, a fin de servir de base para futuros desarrollos.
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Vestin, Albin, and Gustav Strandberg. "Evaluation of Target Tracking Using Multiple Sensors and Non-Causal Algorithms." Thesis, Linköpings universitet, Reglerteknik, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-160020.
Full textAbstract:
Today, the main research field for the automotive industry is to find solutions for active safety. In order to perceive the surrounding environment, tracking nearby traffic objects plays an important role. Validation of the tracking performance is often done in staged traffic scenarios, where additional sensors, mounted on the vehicles, are used to obtain their true positions and velocities. The difficulty of evaluating the tracking performance complicates its development. An alternative approach studied in this thesis, is to record sequences and use non-causal algorithms, such as smoothing, instead of filtering to estimate the true target states. With this method, validation data for online, causal, target tracking algorithms can be obtained for all traffic scenarios without the need of extra sensors. We investigate how non-causal algorithms affects the target tracking performance using multiple sensors and dynamic models of different complexity. This is done to evaluate real-time methods against estimates obtained from non-causal filtering. Two different measurement units, a monocular camera and a LIDAR sensor, and two dynamic models are evaluated and compared using both causal and non-causal methods. The system is tested in two single object scenarios where ground truth is available and in three multi object scenarios without ground truth. Results from the two single object scenarios shows that tracking using only a monocular camera performs poorly since it is unable to measure the distance to objects. Here, a complementary LIDAR sensor improves the tracking performance significantly. The dynamic models are shown to have a small impact on the tracking performance, while the non-causal application gives a distinct improvement when tracking objects at large distances. Since the sequence can be reversed, the non-causal estimates are propagated from more certain states when the target is closer to the ego vehicle. For multiple object tracking, we find that correct associations between measurements and tracks are crucial for improving the tracking performance with non-causal algorithms.
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Shih-nien, Huang, and 黃世年. "Electromagnetic Modal Analysis of Fused 3x3 Fiber-Optic Couplers." Thesis, 1999. http://ndltd.ncl.edu.tw/handle/63397913156294072839.
Full textAbstract:
碩士國立臺灣大學
電信工程學研究所
87
Based on a full-wave vectorial formulation, the surface integral equation method (SIEM) has been employed to investigate the coupling characteristics of fused 3x3 fiber-optic couplers. Three types of 3x3 couplers are considered: the triangular 3x3 couplers for which the three fibers are centered at the vertices of a triangle, the collinear 3x3 couplers for which the centers of the three fibers are aligned in a straight line, and the V-shaped 3x3 couplers for which the three fibers are placed symmetrically but not aligned in a straight line. The propagation constants, the coupling coefficients, the form birefringence, and the field patterns of the first six normal modes of the coupler have been accurately calculated by dividing the boundary contour of the coupler nonuniformly in performing the boundary integrals. The effect of difference between the radii of the central fiber and the side fibers of collinear 3x3 fibers is also considered.
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HanLi and 李翰. "Interaction Style Detection Based on Fused Cross-Correlation Model In Spoken Conversation." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/54379637882331125888.
Full textAbstract:
碩士國立成功大學
資訊工程學系碩博士班
100
Abstract Interaction Style Detection Based on Fused Cross-Correlation Model in Spoken Conversation Han Li* Chung-Hsien Wu** Department of Computer Science and Information Engineering, National Cheng Kung University, Tainan, Taiwan, R.O.C. In this thesis, a multi-modal fusion technology named Fused Cross-Correlation Model (FCCM) is proposed. The user’s emotion, personality trait and dialogue history information are combined for user's interaction style (IS) detection to deal with the problem of monotonic responses in a conventional spoken dialogue system (SDS). The responses generated from the SDS can be versatile based on user's interaction style instead of randomly selecting a pre-defined response, so that the conversations between human and system will be more dynamic and natural. It's not an easy task to detect IS based on the low level features, because IS includes some high level psychological meaning. Accordingly, emotion recognition and personality trait detection are employed in IS detection. Because IS is a long-term external expression, historical conversations' IS information is also integrated into IS detection. Finally, the cross correlation coefficients among emotion, personality trait and history information and IS are estimated using a training corpus for the FCCM construction. Moreover, prosodic features and linguistic features of users' speech are conducted in feature extraction. However, the emotional speech will inflect the performance of auto speech recognizer (ASR). To solve this problem, we separate our corpus into two categories according to the arousal level, and then use them to train the acoustic models of ASR separately. After this process, the result from ASR will be more robust. Then we apply Latent Semantic Analysis (LSA) to extract the latent semantic features, which compose the linguistic features. Support vector machine (SVM) is utilized to train personality trait detection model and IS scoring model. On the other hand, we propose a new method considering emotion temporal course to improve the emotion recognition accuracy. Finally, the result of emotion recognition, personality trait detection, IS scoring and historical IS will be combined and fused into FCCM to get the final IS detection result. Experimental results show that the performance of the proposed approach can achieve 73.09% accuracy, which is 11.21% better than SVM for IS detection. The results confirm that the correlations among IS, emotion and personality trait are beneficial to IS detection in a spoken dialogue system. Keyword - Interaction Style, Fused Cross-Correlation Model, FCCM * The Author ** The Advisor
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Wei-Han, Shih, and 史維漢. "Improving the Quality of Fused Deposition Model and Light Curing 3D Printers -A Case Study of Desktop Model." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/gw3bca.
Full textAbstract:
碩士國立臺北科技大學
管理學院EMBA華南專班
106
In 3D printing, the coordination degree between the molding material and the machine is important, but the original factory is almost 2 times the price of the auxiliary factory. How to reduce the cost by the 3D printing material which is used by the original factory to reduce the cost, and to change the printing parameters to improve the precision of the original plant to replace the raw material price is this disadvantage. The main purpose of this paper is to carry out an experiment in two types of table type machines: 1. molten deposition Fused Deposition Modeling (FDM), 2. light solidified 3D printing, which are the most common forming equipment. Firstly, the failure causes and quality analysis of the printing are discussed, and then the Taguchi method is used to design DOE (Design of Experiments) find out the main factors affecting the quality and the best combination of parameters to make the quality improvement and optimum printing. The experiment proves that the use of the auxiliary material can also achieve the same quality and effectively prevent the poor quality and reduce the printing failure. Yield and accuracy, reduce the number of learning from mistakes, and successfully print at a time as the goal, so as to reduce costs, improve quality and efficiency.