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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Webový systém na prodej předmětů s potiskem pomocí crowdfundingových kampaní / Web System for Crowdfunding Based on Selling Items with Custom Imprint

Škvařil, Jan January 2016 (has links)
The aim of this thesis was to design and implement a web system for organization of crowdfunding campaigns that are based on the sale of items with custom imprint. The implemented system automates and facilitates the whole campaign lifecycle from the design of the imprint in an integrated editor through campaign evaluation up to the distribution of final products to customers. Therefore, there is a minimum number of points where the administrator's action is required. Part of the implementation was also seamless integration with external services like on-line payments, printing house, and social networks. Powered by TCPDF (www.tcpdf.org)
12

Validation of a Task Network Human Performance Model of Driving

Wojciechowski, Josephine Quinn 24 May 2006 (has links)
Human performance modeling (HPM) is often used to investigate systems during all phases of development. HPM was used to investigate function allocation in crews for future combat vehicles. The tasks required by the operators centered around three primary functions, commanding, gunning, and driving. In initial investigations, the driver appeared to be the crew member with the highest workload. Validation of the driver workload model (DWM) is necessary for confidence in the ability of the model to predict workload. Validation would provide mathematical proof that workload of driving is high and that additional tasks impact the performance. This study consisted of two experiments. The purpose of each experiment was to measure performance and workload while driving and attending to an auditory secondary task. The first experiment was performed with a human performance model. The second experiment replicated the same conditions in a human-in-the-loop driving simulator. The results of the two experiments were then correlated to determine if the model could predict performance and workload changes. The results of the investigation indicate that there is some impact of an auditory task on driving. The model is a good predictor of mental workload changes with auditory secondary tasks. However, predictions of the impact on performance from secondary auditory tasks were not demonstrated in the simulator study. Frequency of the distraction was more influential in the changes of performance and workload than the demand of the distraction, at least under the conditions tested in this study. While the workload numbers correlate with simulator numbers, using the model would require a better understanding of what the workload changes would mean in terms of performance measures. / Master of Science
13

Multiscale modeling using goal-oriented adaptivity and numerical homogenization

Jhurani, Chetan Kumar 16 October 2009 (has links)
Modeling of engineering objects with complex heterogeneous material structure at nanoscale level has emerged as an important research problem. In this research, we are interested in multiscale modeling and analysis of mechanical properties of the polymer structures created in the Step and Flash Imprint Lithography (SFIL) process. SFIL is a novel imprint lithography process designed to transfer circuit patterns for fabricating microchips in low-pressure and room-temperature environments. Since the smallest features in SFIL are only a few molecules across, approximating them as a continuum is not completely accurate. Previous research in this subject has dealt with coupling discrete models with continuum hyperelasticity models. The modeling of the post-polymerization step in SFIL involves computing solutions of large nonlinear energy minimization problems with fast spatial variation in material properties. An equilibrium configuration is found by minimizing the energy of this heterogeneous polymeric lattice. Numerical solution of such a molecular statics base model, which is assumed to describe the microstructure completely, is computationally very expensive. This is due to the problem size – on the order of millions of degrees of freedom (DOFs). Rapid variation in material properties, ill-conditioning, nonlinearity, and non-convexity make this problem even more challenging to solve. We devise a method for efficient approximation of the solution. Combining numerical homogenization, adaptive finite element meshes, and goaloriented error estimation, we develop a black-box method for efficient solution of problems with multiple spatial scales. The purpose of this homogenization method is to reduce the number of DOFs, find locally optimal effective material properties, and do goal-oriented mesh refinement. In addition, it smoothes the energy landscape. Traditionally, a finite element mesh is designed after obtaining material properties in different regions. The mesh has to resolve material discontinuities and rapid variations. In our approach, however, we generate a sequence of coarse meshes (possibly 1-irregular), and homogenize material properties on each coarse mesh element using a locally posed constrained convex quadratic optimization problem. This upscaling is done using Moore-Penrose pseudoinverse of the linearized fine-scale element stiffness matrices, and a material independent interpolation operator. This requires solution of a continuous-time Lyapunov equation on each element. Using the adjoint solution, we compute local error estimates in the quantity of interest. The error estimates also drive the automatic mesh adaptivity algorithm. The results show that this method uses orders of magnitude fewer degrees of freedom to give fast and approximate solutions of the original fine-scale problem. Critical to the computational speed of local homogenization is computing Moore-Penrose pseudoinverse of rank-deficient matrices without using Singular Value Decomposition. To this end, we use four algorithms, each having different desirable features. The algorithms are based on Tikhonov regularization, sparse QR factorization, a priori knowledge of the null-space of the matrix, and iterative methods based on proper splittings of matrices. These algorithms can exploit sparsity and thus are fast. Although the homogenization method is designed with a specific molecular statics problem in mind, it is a general method applicable for problems with a given fine mesh that sufficiently resolves the fine-scale material properties. We verify the method using a conductivity problem in 2-D, with chessboard like thermal conductivity pattern, which has a known homogenized conductivity. We analyze other aspects of the homogenization method, for example the choice of norm in which we measure local error, optimum coarse mesh element size for homogenizing SFIL lattices, and the effect of the method chosen for computing the pseudoinverse. / text
14

Polymer based nano- and micro-photonic devices for three-dimensional optical interconnects

Dou, Xinyuan 11 February 2011 (has links)
The demand for higher bandwidth and higher speed driven by semiconductor technology development draws a great deal of research efforts devoted to the development of high speed data communication. Challenges on electrical copper interconnects at high frequency make optical interconnect technologies become a promising alternative to conventional electrical interconnects at different levels. This doctoral dissertation describes polymer based nano- and micro-photonic devices for three-dimensional optical interconnects. Two areas are focused, (1) polymer based two-dimensional (2D) and three-dimensional (3D) photonic crystal fabrication and simulation for laser beam steering applications, (2) polymer based optical waveguide array and shared bus waveguide with embedded 45° micro-mirrors for board level optical interconnects. A three-dimensional (3D) face-centered cubic (FCC) type polymer based photonic crystal using the polymer material SU-8 was simulated and successfully fabricated using a polygonal prism based holographic fabrication method. The theoretical study of polymer based photonic crystals was carried out for laser beam steering, which is based on the superprism effect. Horizontally stacked two-dimensional (2D) photonic crystal was fabricated by a double exposure holographic interference method. The k-vector superprism effect, the principle for beam steering, was studied in detail through EFC (Equi-frequency Contour) analysis. A polymer based optical waveguide array with embedded 45° micro-mirrors for board level optical interconnects was prepared using a Ni metal hard mold by a UV imprint technique. A nickel based metal mold with 45º tilted surfaces on both ends of the channel waveguide was prepared through the electroplating process. To obtain a precise 45º tilted angle, a 50µm thick SU-8 layer was exposed under de-ionized water. High speed optical testing (10Gb/s) was carried out on the polymeric optical waveguide array with embedded 45º micro-mirrors on flexible substrate for out-of-plane optical interconnects. A polymer based 3-to-3 shared optical bus waveguide with opposite 45º micro-mirrors was designed and fabricated using the metallic hard mold method. The Ni metal hard mold was successfully prepared using the Ni electroplating method. This metallic hard mold provides a convenient way to fabricate the polymeric optical bus waveguide devices through the imprint technique. / text
15

Památník vzpomínek / Scrapbook of Memories

BARTUŠKOVÁ, Jana January 2014 (has links)
The theme of this work is memory and memory's retained memories associated with emotions. Memories which can be stored and recalled are often times associated with certain objects. On this issue, opinions by psychologist and sociologist Bohuslav Beetle and aesthetics and philosopher Dušan Sindelar are selected. The concept created on the basis of the theoretical part of the thesis brought in solutions in several different fingerprint files, which symbolize transience and fragility of memories in our lives.
16

Polarity učení / Polarity of teaching

Bobáková, Natália January 2018 (has links)
The diploma thesis deals with the interconnection between medium of collective action, sport and painting. Using yoga lectures taking place every wednesday in studio of evening drawing autor observed roles of teacher, student and their interconnections. The documetation reamined on the canvas. Every lecture was different. Every canvas was different.
17

Fabrication Of Metallic Antenna Arrays Using Nanoimprint Lithography

Lin, Yu-Wei 01 January 2013 (has links)
This Thesis describes the development of a cost-effective process for patterning nanoscale metal antenna arrays. Soft ultraviolet (UV) Nanoimprint Lithography (NIL) into bilayer resist was chosen since it enables repeatable large-scale replication of nanoscale patterns with good lift-off properties using a simple low-cost process. Nanofabrication often involves the use of Electron Beam Lithography (EBL) which enables the definition of nanoscale patterns on small sample regions, typically < 1 mm 2 . However its sequential nature makes the large scale production of nanostructured substrates using EBL cost-prohibitive. NIL is a pattern replication method that can reproduce nanoscale patterns in a parallel fashion, allowing the low-cost and rapid production of a large number of nanopatterned samples based on a single nanostructured master mold. Standard NIL replicates patterns by pressing a nanostructured hard mold into a soft resist layer on a substrate resulting in exposed substrate regions, followed by an optional Reactive Ion Etching (RIE) step and the subsequent deposition of e.g. metal onto the exposed substrate area. However, non-vertical sidewalls of the features in the resist layer resulting from an imperfect hard mold, from reflow of the resist layer, or from isotropic etching in the RIE step iii may cause imperfect lift-off. To overcome this problem, a bilayer resist method can be used. Using stacked resist layers with different etch rates, undercut structures can be obtained after the RIE step, allowing for easy lift-off even when using a mold with non-vertical sidewalls. Experiments were carried out using a nanostructured negative SiO2 master mold. Various material combinations and processing methods were explored. The negative master mold was transferred to a positive soft mold, leaving the original master mold unaltered. The soft mold consisted of a 5 m thick top Poly(methyl methacrylate) (PMMA), or Polyvinyl alcohol (PVA) layer, a 1.5 mm thick Polydimethylsiloxane (PDMS) buffer layer, and a glass supporting substrate. The soft mold was pressed into a bilayer of 300 nm PMMA and 350 nm of silicon based UV-curable resist that was spin-coated onto a glass slide, and cured using UV radiation. The imprinted patterns were etched using RIE, exposing the substrate, followed by metal deposition and lift-off. The experiments show that the use of soft molds enables successful pattern transfer even in the presence of small dust particles between the mold and the resist layer. Feature sizes down to 280 nm were replicated successfully
18

Age-related changes in the skulls of Japanese macaques / ニホンザルの頭骨の年齢変化

Nguyen, Van Minh 24 September 2015 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(理学) / 甲第19265号 / 理博第4120号 / 新制||理||1593(附属図書館) / 32267 / 京都大学大学院理学研究科生物科学専攻 / (主査)教授 濱田 穣, 准教授 平﨑 鋭矢, 教授 中村 克樹 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DFAM
19

Electrical characterization of ferroelectric capacitors for non-volatile memory applications

Thio, Chai-Liang 23 December 2009 (has links)
Ferroelectric materials show a spontaneous electrical polarization that can be reversed in sense by an applied external electric field. It should, therefore, be feasible to build a ferroelectric memory device that can store information in digital form. Ascertaining the suitability of a ferroelectric material for use in memory devices requires an understanding of electrical properties of the thin-film capacitor. There are a number of electrical characterization methods which can be used to investigate these electrical properties. The polarization mechanism can be studied by the most fundamental characterization technique for ferroelectrics, the hysteresis loop, which is derived by plotting polarization against applied field. Fatigue, retention and imprint, which are specific ferroelectric lifetime characterization methods, are employed to determine the rate of capacitor degradation as well as the mechanisms responsible for it. The DC conductivity characterization techniques, including leakage current, resistivity degradation and time dependent dielectric breakdown (TDDB) are used to study the electrical current properties and charge transport mechanism in memory applications. Finally, the AC conductivity (complex impedance) characterization method, introduced here for the first time for ferroelectric capacitors, permits further understanding of the charge transport mechanism of ferroelectric materials. However, this characterization method is not directly used to evaluate the application of ferroelectrics in memory devices, but it can provide a further physical understanding of ferroelectric capacitors, such as the understanding of fatigue. PbZr<sub>x</sub>Ti<sub>1-x</sub>O₃ (PZT), a ferroelectric material with a pseudo-cubic perovskite-type structure, has been the material of choice in all major ferroelectric random access memory (FRAM) development programs to date. However, degradation problems such as fatigue and imprint that affect the lifetime of ferroelectric capacitors have moderated the progress of using PZT in commercial ferroelectric memories. Recently, SrBi₂Ta₂O₉ (SBT), a ferroelectric material that crystallizes in a layered structure, has been identified as a promising candidate for FRAM applications as a result of its fatigue-free behavior. In this research, the performance of PZT and SBT as ferroelectric memory materials is compared by using the aforementioned electrical characterization methods. / Master of Science
20

Ativação da resposta a proteínas mal formadas - UPR na prole de camundongos com obesidade induzida por dieta hiperlipídica durante a gestação e lactação / Activation of unfolded proteins response - UPR in the offspring of mice with obesity induced by high fat diet during pregnancy and lactation

Melo, Arine de Mattos, 1989- 10 February 2013 (has links)
Orientador: Marcio Alberto Torsoni / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Ciências Aplicadas / Made available in DSpace on 2018-08-23T21:16:07Z (GMT). No. of bitstreams: 1 Melo_ArinedeMattos_M.pdf: 2027179 bytes, checksum: 2320e20506f524d224919f97ec6056eb (MD5) Previous issue date: 2013 / Resumo: É conhecido que a obesidade materna durante a gestação e lactação expõe a prole a condições inflamatórias e leva a distúrbios metabólicos e obesidade na vida adulta. Porém, não é conhecido se o evento celular relacionado aos danos da sinalização hipotalâmica, como o estresse de retículo endoplasmático (ERE) e resistência à insulina, poderia estar presente na prole. Para responder essa questão, nós avaliamos o tecido hipotalâmico e hepático em camundongos recém desmamados (d28) e o hipotálamo de camundongos recém nascidos (d0) de mães alimentadas com dieta rica em gordura (HFD-O) e dieta controle (SC-O) durante a gestação e lactação. Peso corpóreo, massa do tecido adiposo, e ingestão alimentar foram mais acentuados em camundongo HFD-O que em camundongo SC-O. Além disso, intolerância a glicose (GTT) e insulina (ITT) foram maior em HFD-O que em SC-O. Comparado com SC-O, os níveis de RNAm de IL1-?, expressão proteica de NF?B e p-JNK no hipotálamo foram aumentados em HFD-O. Além disso, comparado ao SC-O, a fosforilação da AKT hipotalâmica após estímulo com insulina foi reduzida, enquanto os marcadores de ERE (p-PERK, p-eIF2?, XBP1s, GRP78 e GRP94) foram aumentados no tecido hipotalâmico de HFD-O com d28 mas não com d0. A fosforilação hipotalâmica da AMPK estava aumentada em HFD-O comparado a SC-O com d28. Esses danos na sinalização hipotalâmica foram acompanhados de alterações hepáticas evidenciadas pelo aumento de depósito de triglicérides, ativação de proteínas próinflamatórias (NF?B, p-IKK e p-JNK), e marcadores de ERE (p-PERK e p-eIF2?). Esses resultados indicam fortemente que o período de lactação é importante para as mudanças metabólicas. Essas mudanças podem ocorrer precocemente na prole de mães obesas e contribuir para a obesidade e patologias associadas / Abstract: It is known that maternal obesity during pregnancy and lactation exposes offspring to inflammatory conditions and leads to metabolic disturbances and obesity in adult offspring. However, it is unknown whether the cellular events related to the damage to hypothalamus signaling, such as endoplasmic reticulum stress (ERS) and insulin resistance, could be present early in the offspring. To address this question, we evaluated the hypothalamic and hepatic tissues in recently weaned mice (d28) and the hypothalamus of newborn mice (d0) from dams fed HFD (HFD-O) or standard chow diet (SC-O) during pregnancy and lactation. Body weight, adipose tissue mass, and food intake were more accentuated in HFD-O mice than in SC-O mice. In addition, intolerance to glucose (GTT) and insulin (ITT) was higher in HFD-O mice than in SC-O mice. Compared with SC-O mice, levels of hypothalamic IL1-? mRNA, NF?B protein, and p-JNK were increased in HFD-O mice. Furthermore, compared with SC-O mice, hypothalamic AKT phosphorylation after insulin challenge was reduced, while markers of ERS (p-PERK, p-eIF2?, XBP1s, GRP78, and GRP94) were increased in the hypothalamic tissue of HFD-O at d28 but not at d0. Hypothalamic AMPK phosphorylation was higher in HFD-O mice than in SC-O mice at d28. These damages to hypothalamic signaling were accompanied by hepatic alterations evidenced by increased triglyceride deposits, activation of proinflammatory proteins (NF?B, p-IKK, and p-JNK), and markers of ERS (p-PERK and p-eIF2?). Taken together, these results strongly indicate that the lactation period is important for metabolic changes. These changes may occur early in offspring from obese dams and contribute to obesity and associated pathologies / Mestrado / Metabolismo e Biologia Molecular / Mestra em Ciências da Nutrição e do Esporte e Metabolismo

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