Cíl disertační práce leží v oblasti modelování a vyhodnocení bezdrátových komunikačních systémů s dvojrozměrným rozprostíráním signálu a jejich klíčových parametrů v závislosti na vybraných vlastnostech moderního bezdrátového komunikačního řetězce. Výzkumné metody použité v této práci spočívají především ve vývoji softwarového simulátoru pro prostředí Matlab, s jehož pomocí, a s využitím statistického přístupu, jsou navržené algoritmy ověřeny. Dále je použit simulátor fyzické vrstvy dle 3rd Generation Partnership Project Long Term Evolution (3GPP LTE), vyvinutý na Technické univerzitě ve Vídni. Tento představuje ideální platformu pro implementaci metody dvojrozměrného (2D) rozprostírání a její vyhodnocení s přihlédnutím k současným bezdrátovým komunikačním systémům. Zjištění prezentovaná v této práci představují především ověření účinnosti systému nazvaného jako Variable Spreading Factor - Orthogonal Code Frequency Division Multiplex (VSF-OFCDM), který využívá principu 2D rozprostírání signálu a zjištění, že VSF-OFCDM systém překonává systémy využívající Orthogonal Division Frequency Multiplex (OFDM), nebo Code Division Multiple Access (CDMA). Dále byla navržena metoda 2D rozprostírání signálu v systému LTE, kde se též potvrdila její účinnost. Díky účinnějšímu potlačení vlivu rychlé variace přenosového kanálu v závislosti na frekvenci a čase, dosahuje systém VSF-OFCDM znatelně vyšší datové prostupnosti.

Abstracts of the conference 'Diffusion Fundamentals VIII - Deffusion Phenomena Moving People', September 1-5, 2019, Erlangen, Germany

Heterogeneity in lattice potentials (like random or quasiperiodic) can localize linear, non-interacting waves and halt their propagation. Nonlinearity induces wave interactions, enabling energy exchange and leading to chaotic dynamics. Understanding the interplay between the two is one of the topical problems of modern wave physics. In particular, one questions whether nonlinearity destroys localization and revives wave propagation, whether thresholds in wave energy/norm exist, and what the resulting wave transport mechanisms and characteristics are. Despite remarkable progress in the field, the answers to these questions remain controversial and no general agreement is currently achieved. This thesis aims at resolving some of the controversies in the framework of nonlinear dynamics and computational physics. Following common practice, basic lattice models (discrete Klein-Gordon and nonlinear Schroedinger equations) were chosen to study the problem analytically and numerically. In the disordered linear case all eigenstates of such lattices are spatially localized manifesting Anderson localization, while nonlinearity couples them, enabling energy exchange and chaotic dynamics. For the first time we present a comprehensive picture of different subdiffusive spreading regimes and self-trapping phenomena, explain the underlying mechanisms and derive precise asymptotics of spreading. Moreover, we have successfully generalized the theory to models with spatially inhomogeneous nonlinearity, quasiperiodic potentials, higher lattice dimensions and arbitrary nonlinearity index. Furthermore, we have revealed a remarkable similarity to the evolution of wave packets in the nonlinear diffusion equation. Finally, we have studied the limits of strong disorder and small nonlinearities to discover the probabilistic nature of Anderson localization in nonlinear disordered systems, demonstrating the finite probability of its destruction for arbitrarily small nonlinearity and exponentially small probability of its survival above a certain threshold in energy. Our findings give a new dimension to the theory of wave packet spreading in localizing environments, explain existing experimental results on matter and light waves dynamics in disordered and quasiperiodic lattice potentials, and offer experimentally testable predictions.

El presente trabajo de investigación se realiza el desarrollo de negocio que busca ofrecer una alternativa de diversión a un nicho de mercado en Lima Metropolitana, específicamente, en Lima Moderna que comprende distritos como Barranco, La Molina, Miraflores, San Borja, San Isidro, Surco, Surquillo entre otros; a personas entre 21 y 40 años, propuesta enmarcada dentro de las ferias o festivales que vienen desarrollándose en los parques y al aire libre durante los fines de semana, como son los food trucks donde se expende comidas, y además ofrece algunas alternativas de recreación pero orientado a los niños. Esta propuesta consiste en una plataforma de baile y canto (karaoke) dentro de estas ferias al aire libre, proyectados en una pantalla ecran y usando equipos de última generación, presentando diversas canciones de moda y clásicas, así como diferentes formatos de baile; todo ello permitirá a todos los asistentes, disfrutar un momento sano de diversión. En el trabajo se desarrolla los Aspectos generales del negocio, Planeamiento estratégico donde se realiza una análisis externo e interno, se plantea la misión, visión y objetivos; la investigación y validación del mercado, la cual se realizó a través de encuestas virtuales iniciales y encuestas in situ, es decir, dentro de las ferias o food trucks, para validar las preferencias de alternativas de diversión que el público busca encontrar. / In this research work is carried out the commercial development that seeks to offer a fun alternative to a niche market in Metropolitan Lima, specifically, in Modern Lima that includes districts such as Barranco, La Molina, Miraflores, San Borja, San Isidro, Surco, Surquillo among others; For people between 21 and 40, a proposal framed within fairs or festivals that take place in the parks and outdoors on weekends, such as food trucks where food is sold, and also offers some alternatives recreational but child oriented. This idea consists of a platform of dance and singing (karaoke) within these outdoor fairs, projected on an ecran screen and using modern equipment, presenting several classic and latest songs of 2019, as well as different dance formats; All this will allow all attendees to enjoy and have the best experience. In this project, principal aspects of the business are developed, Strategic planning where an external and internal analysis are carried out, the mission, vision and objectives are raised; Market Research and validation, which was carried out through initial virtual surveys and on-site surveys, that is, within fairs or food trucks, to validate the preferences of fun alternatives that the public are looking for. / Trabajo de investigación

No description available.

Context: Obesity is a growing global health concern. The increased body mass and altered mass distribution associated with obesity may be related to increases in plantar shear that putatively leads to physical functional deficits. Therefore, measurement of plantar shear may provide unique insights on the effects of body mass and body distribution on physical function or performance. Purpose: 1) To investigate the effects of body mass and distribution on plantar shear; 2) To examine how altered plantar shear influences postural control and gait kinetics. Hypothesis: 1) a weighted vest forward distributed (FV) would shift the center of pressure (CoP) location forward during standing compared with a weighted vest evenly distributed (EV); 2) FV would increase plantar shear spreading forces more than EV during standing; 3) FV would increase postural sway during standing while EV would not; and 4) FV would increase peak braking force, plantar impulses, and plantar shear spreading forces during walking more than EV. Methods: Twenty healthy young males participated in four different tests: 1) static test (for measuring plantar shear and CoP location without acceleration; 2) two-leg standing postural control test; 3) one-leg standing postural test; and 4) walking test. All tests were executed in three different weight conditions: 1) unweighted (NV); 2) evenly distributed vest (EV) with 20% added body mass; and 3) front-loaded vest (FV), also with 20% added body mass. Plantar shear stresses were measured using a pressure/shear device, and several shear and postural control metrics were extracted. Repeated measures ANOVAs with Holms post hoc test were used to compare each metric among the three conditions (α = 0.05). Results: FV and EV increased both anterior-posterior and medial-lateral plantar shear forces in single-foot trials compared to NV. FV shifted CoP forward. FV and EV showed decreased CoP range and velocity and increased time-to-boundary (TTB) during postural control compared to NV. While EV increased medial-lateral plantar shear spreading force, FV increased anterior-posterior plantar shear spreading force during walking. Conclusion: Added body mass increases plantar shear spreading forces. Body mass distribution had greater effects during dynamic tasks. In addition, healthy young individuals seem to quickly adapt to external stimuli to control postural stability. However, the interactive effects between body mass and distribution may disrupt physical function and/or performance in other populations—such as elderly, obese, and diabetes. Plantar shear may play a critical role in clinical diagnosis. However, as it is the first step study, follow-up studies are necessary to further support the clinical role of plantar shear.

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Part 1: Monitoring Response to Single-Dose (1000cGy) Radiotherapy in a RIF-1 Tumor Model The current standard of measure for monitoring chemotherapeutic and radiotherapeutic treatment response is tumor volume. Unfortunately, changes in tumor volume are generally slow and tumor volume does not necessarily indicate the degree of tumor viability. The development of marker(s) with the ability to detect an early therapeutic response would greatly aid in patient management, opening the possibility for both rapid dose optimization and replacement of ineffective therapies with alternative treatment. Previous studies have shown that diffusion measurements using magnetic resonance imaging (MRI) techniques are sensitive to therapy-induced changes in cellular structure, allowing demarcation between regions of necrosis and viable tumor tissue. This sensitivity, based on the correlation between water apparent diffusion coefficient (ADC) values and tumor cellular density, may allow diffusion measurements to be employed in non-invasive monitoring of treatment response. Therapy-induced increases in tumor ADC preceding tumor regression have been reported in a variety of experimental tumor models and several human brain tumors. Despite the demonstrated diffusion sensitivity to therapeutic response in these particular studies, shortcomings still remain that hinder the efficacy of clinical application in oncology. Earlier studies have concentrated on the mean ADC present within the tumor, either within the entire tumor volume or a region of-interest (ROI) defined by the user, and their evolution pre-treatment and post-treatment. Because of inter- and intra-tumor heterogeneity, volume-averaged ADC measurements suffer from poor correlation with treatment efficacy. In addition, most studies make little or no attempt to characterize the entire tumor volume (necrotic, viable, edema). The identification of regions of differing tissue viability should aid in the staging of treatment, therefore making accurate and reproducible tissue segmentation an important goal. The results of earlier, single-parameter studies indicate that a multi-parametric approach in which several MR parameters are monitored (ADC, T2, M0) may provide greater power than that of the single parameter approach. A multi-parametric or multi-spectral (MS) analysis uses pattern-recognition techniques, such as clustering, for image segmentation. Clustering algorithms use characteristics of the multiple MR-parameter dataset to group tissue of similar type, e.g., fat, muscle, viable tumor, necrosis. Specifically, k-means (KM) is an unsupervised segmentation algorithm that groups together similar tissue based on the difference in MR parameter space between the image voxel of interest and the mean parameter values of the voxels in that cluster. In the first step of the classification algorithm, it is applied to separate the data into two clusters (k = 2), tissue and background noise voxels. All voxels classified as background noise are set to zero and removed from further processing. In the second step, KM is applied to the remaining tissue voxels to segment the data into multiple tissue types. In the case of tumors, it is not clear in advance how many different types of tissue exist. The number of clusters, k, should be varied to ensure that all relationships between tissues are found. In the final step, the resulting KM maps may be compared to histological slices taken from the same tissue as the imaging slices in order to identify the tissue type of each cluster. In line with the studies and analyses described above, quantitative MRI was performed to investigate the spatial correlation between ADC, spin-spin (T2) relaxation times, and proton density (M0) in murine radiation-induced fibrosarcoma (RIF-1) tumors following single-dose (l000cGy) radiotherapy using the KM algorithm (Chapters 3 and 4) and different combinations of features and/or clusters. For all cluster/feature combinations, an in-depth comparison between KM-derived volume estimates and conventional histology via the hematoxylin-eosin (H&E) staining procedure (for identification of viable tumor versus necrosis), as well as via hypoxic-inducible factor-lα. (HIF-1α) immunohistochemistry (for identification of regions of hypoxia versus well-oxygenated tissue) was performed (Chapter 3). The optimal cluster/feature combination was determined by minimizing the sum-of-squared-differences (SSD) between the actual datapoints and the ideal one-to-one correlation that should exist between KM-derived volume estimates and histology-derived volume estimates. The optimal cluster/feature combination was determined to be a 2-feature (ADC, T2) and 4-c1uster (2 regions each of viable tissue and necrosis) segmentation. This KM method was then applied in analysis of the radiotherapeutic response: first, to gain insight into the various processes whose combination yield the total ADC response over time; second, to identify the contribution of tissue heterogeneity to the treatment response and changes in tumor growth kinetics and cell kill (Chapter 4). Comparisons between control and various time-points out to 14 days post-radiotherapy permitted more accurate tissue characterization and prediction of therapeutic outcome over analysis using ADC alone. The results based on histological validation demonstrated: (1) MS analysis provides an improved tissue segmentation method over results obtained from conventional methods employing ADC alone; (2) MS analysis permits subdivision based on the degree of necrosis, as well as delineation between well-oxygenated and hypoxic viable tissue; and (3) Individual KM volumes corresponded well with both H&E volumes and regions with increased HIF-1α expression. The results based on the radiotherapeutic response demonstrated: (1) MS analysis provides a method for monitoring the range of tissue viability as a function of time post-treatment; (2) MS analysis permits assessment of the various contributions to the total ADC response post-treatment; (3) The relative fractions of well-oxygenated (i.e., radiosensitive) versus hypoxic (i.e., radioresistant) tissue pretreatment may be predictive of treatment response; and (4) The early ADC increase did not seem to be a result of radiation-induced vasogenic edema, but instead was most likely due to a slight reduction in cellular density following therapy. These studies provide a non-invasive method of tissue characterization that may be used in monitoring treatment response and optimizing drug dose-timing schemes, with the potential for predicting treatment efficacy. Part 2: Role of Spreading Depression in Ischemic Stroke Stroke is a prevalent disease that ranks as the 3rd leading cause of death and disability in the United States, according to NIH statistics, costing millions of dollars in medical costs and lost wages. At present, the mechanism by which focal ischemia evolves into infarction remains poorly understood. By determining the patho-physiological mechanisms involved in the evolution of focal brain ischemia, therapeutic strategies may be designed for instances of acute ischemic stroke. In the late 1980s, researchers discovered MRI techniques that allow the detection of stroke very early after onset. Such techniques as diffusion-weighted imaging and perfusion-weighted imaging (DWI and PWI) have been applied both clinically and experimentally. Previous studies employing these techniques suggest that cortical spreading depression plays a detrimental role in the evolution of focal brain ischemia. Spreading depression (SD) is characterized by a spontaneous and reversible depression of cortical electrical activity that spreads from the site of onset as a wave with a speed of 2-5 mm/min. It is accompanied by an ionic redistribution, with efflux of potassium ions (K+) and influx of sodium, chloride, and calcium (Na+, Cl-, Ca2+) ions, as well as water. This results in cellular swelling and a decreased extracellular space (ES), yielding a decline in ADC. A positive correlation between the number of both spontaneous and induced SDs and infarct volume has well been documented, supporting the idea that SD inhibition might be neuroprotective if initiated early after ischemic onset. Even though these studies show promise in their ability to track SD using diffusion mapping, changes in ADCs reflect cytotoxic edema and do not necessarily correspond to SD or SD-like depolarizations or calcium (Ca2+) influx, leading to cell death. Recent studies have reported the use of manganese ions (Mn2+) as a depolarization-dependent contrast agent in monitoring brain activation through the application of glutamate, as well as in the study focal ischemia. Since extracellular accumulation of potassium (K+) ions or glutamate in ischemic tissue is believed to play a central role in the initiation and propagation of SDs, and knowing that Mn2+, having an ionic radius similar to that of Ca2+, is handled in a manner similar to Ca2+, these studies suggest the possible use of manganese ions (Mn2+) in tracking SD or SD-like depolarizations in the evolution of focal brain ischemia. In order to determine the utility of Mn2+ as a marker for SD, two sets of T1-weighted MRI experiments were performed before applying Mn2+ in an experimental stroke model (Chapter 6). First, for verification purposes, a glutamate administration group was evaluated to validate our use of the manganese-enhanced MRI (MEMRI) method previously developed by Aoki et al, a modification of the original by Lin and Koretsky. When satisfied that the contrast enhancement was specific to glutamate only, a second set of experiments was performed. Here, experimental SD was elicited by chemical stimulation (direct application of concentrated potassium chloride [KC1] on the exposed cortical surface) and compared with control conditions (perfusion of sodium chloride [NaC1] on exposed brain cortex). This study demonstrated: (1) Mn2+, specific to Ca2+ channel activity, is a more accurate marker for SD than DWI or T2 methods; (2) Cortical restriction of MEMRI enhancement supports the contention that apical dendrites are necessary for SD propagation; (3) Subcortical enhancement is a result of corticalsubcortical neuronal connectivity; and (4) Because of the relatively slow clearance of Mn2+, MEMRI permits higher spatial resolution and signal-to-noise ratios (SNRs) via increased signal averaging. Based on these results, preliminary experiments involving the study of SD in focal ischemia using Mn2+ were performed (Chapter 7). Initial results indicate: (1) MEMRI of ischemia, when compared with standard DWI/PWI methods, may provide a method for estimating the likelihood of progression to infarct at acute time points post onset of stroke. These studies provide a foundation for further investigation into the role of SD in stroke, and the application of Mn2+ towards the design of therapeutic strategies targeting SD inhibition. Conclusions and Medical Significance The research within this dissertation employed magnetic resonance imaging techniques for monitoring the temporal evolution of pathological disease states such as focal ischemia and cancer, with and without therapeutic intervention. Optimization of these techniques in experimental models will open the possibility for future application in a clinical setting. Clinical availability of these non-invasive methods, with the ability to detect an early therapeutic response or to provide staging and prediction of tissue fate, would greatly aid in patient management of both cancer and stroke.

Relative plate motion history since 30 Ma between the Pacific and the southern portion of the Nazca (Farallon) plates is examined. The history is constrained by available seafloor magnetic anomaly data and a two-minute grid of predicted bathymetry derived from satellite altimetry and shipboard sensors. These data are used to create a new plate motion reconstruction based on new magnetic anomaly identifications and finite poles of motion. The new identified magnetic isochrons and tectonic reconstruction provides greater resolution to the tectonic history between chrons 7y (24.73 Ma) and 3 (4.18 Ma) than previous interpretations. Shipboard magnetics and aeromagnetic data from over 250 expeditions were plotted and used to extrapolate magnetic anomalies picked from 2D magnetic modeling from selected cruises. Magnetic anomalies were further constrained by tectonic features evident in the predicted bathymetry. Previously published magnetic anomaly locations consistent with this work were used where interpretation could not be constrained by 2D modeling and map extrapolation. Point locations for anomalies were used as input for calculation of finite poles of motion for chrons 10y, 7y, 6c, 5d, 5b, 5aa, 5o, 4a and 3a. An iterative process of anomaly mapping, pole calculation and anomaly point rotations was used to refine the finite poles of motion. Eleven stage poles were calculated from the nine finite poles from this study and two published instantaneous Euler vectors. Tectonic reconstructions indicate a history dominated by two major southward ridge propagation events, the first starting by 28 Ma and completed by 18 Ma. The second event initiated in association with breakup of the Farallon plate around 24 Ma and ceased by about 11 Ma. Lithosphere was transferred from Nazca to Pacific during the first event and in the opposite sense during the second. Development of the Mendoza microplate east of the later propagator occurred at about 20 Ma and this dual spreading process appears to have lasted until about 15 Ma.

La thèse porte sur l’étude de l’influence des textures sur le mouillage et la propulsion. Trois situations ont été considérées, selon la taille des textures utilisées.Des textures nanométriques hydrophobes permettent d’obtenir des surfaces aérophiles. Lorsque ces surfaces sont immergées dans un bain, elles restent recouvertes d’un fin film d’air et ouvrent toute une classe de nouveaux problèmes de mouillage, où les interfaces gaz – liquide sont inversées par rapport aux situations traditionnelles. Nous avons décrit l’étalement d’une bulle d’air sur une surface aérophile, la dépression capillaire ou encore la dynamique de bulles sur des fils.En situation de lévitation, des textures de l’ordre du millimètre permettent de rediriger efficacement le flux d’air qui sépare un objet de son support. L’écoulement étant contrôlé, une direction privilégiée peut être choisie et l’objet se trouve alors efficacement propulsé. Selon l’emplacement des textures, un entrainement visqueux ou une propulsion par effet fusée peuvent être observés.Sur des créneaux millimétriques recouverts de nanotextures hydrophobes, l’eau est en situation non-mouillante. Il suffit d’une toute petite inclinaison de la surface pour qu’une goutte dévale, et elle atteint rapidement des vitesses importantes puisque la friction est très faible. La présence des macrotextures sur la surface permet de ralentir considérablement la goutte : l’étude a porté sur l’optimisation du contrôle d’une goutte, éventuellement visqueuse. / This thesis deals with the influence of textures on wetting and propulsion. Three situations have been considered, depending on the texture size.Aerophilic surfaces can be obtained with hydrophobic nanometric structures. When immerged in a liquid bath, these surfaces remain covered by a thin plastron of air. This oppens a new class of problems where gas – liquid interfaces are exchanged, compared to usual studies. We described the spreading of an air bulle over an aerophilic surface, capillary depression and the dynamics of a bubble on a wire.Millimetric sutructures allow an efficient redirection of the air cushion between a levitating object and its substrate. Because the flux is controlled, a specific direction can appear, and the object is efficiently propelled. Depending on the textures location, viscous entrainement or rocket effect can be the propulsive mechanism.Hydrophobic nanotextures are used to generate non-wetting situation of water. A tiny angle of tilt of the surface is enough to see a drop mouving; its velocity is high because of the low friction. Macrotextures, as millimetric crennels slow down very efficiently the drop: the study optimized the control of the drop (possibly viscous) motion.