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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.
871

A Surveillance System to Create and Distribute Geo-Referenced Mosaics Using SUAV Video

Andersen, Evan D. 14 June 2008 (has links)
Small Unmanned Aerial Vehicles (SUAVs) are an attractive choice for many surveillance tasks. However, video from an SUAV can be difficult to use in its raw form. In addition, the limitations inherent in the SUAV platform inhibit the distribution of video to remote users. To solve the problems with using SUAV video, we propose a system to automatically create geo-referenced mosiacs of video frames. We also present three novel techniques we have developed to improve ortho-rectification and geo-location accuracy of the mosaics. The most successful of these techniques is able to reduce geo-location error by a factor of 15 with minimal computational overhead. The proposed system overcomes communications limitations by transmitting the mosaics to a central server where there they can easily be accessed by remote users via the Internet. Using flight test results, we show that the proposed mosaicking system achieves real-time performance and produces high-quality and accurately geo-referenced imagery.
872

Family Stabilization: Does it Work?

McKindley, Angela M 01 June 2016 (has links)
ABSTRACT The purpose of this research study on family stabilization is to identify whether this program is working while CalWORKs participants are achieving their educational goals. Family stabilization is a county program that assists those who need supportive services in domestic violence, mental health, substance abuse, and homelessness. The first phase was to assess the participant’s knowledge and understanding of the family stabilization program. The second phase involved a focus group, who could express their questions or concerns regarding the family stabilization program. The final stage was to review and interpret the information provided, in hopes to clarify the participants understanding of the family stabilization program is and the services that are available. Results of this study could not answer the proposed research question, Family Stabilization: Does it Work? There was a lack of significance regrading knowledge of the family stabilization program from the CalWORKs participants. This study does show that communication between the participants and the county offices needs improvement; especially on the availability of programs. The weakness pertained to the sample size and duration of the research project. I do find the research as creditable due to the personal interviews pertaining to their understanding of family stabilization. To completely understand how this research project was conducted and analyzed, readers need a fairly refined knowledge of social science research methods.
873

Analyse de problèmes inverses et directs en théorie du contrôle / Analysis of inverse and direct problems in control theory

Lagache, Marc-Aurèle 19 October 2017 (has links)
Le contexte général de cette thèse est l’étude de problèmes inverses et directs en théorie du contrôle. Plus précisément, les trois problèmes étudiés sont les suivants.Le premier est un problème de contrôle optimal (approche directe). Il s’agit de fournir la synthèse temps minimum du modèle cinématique d'un drone volant à altitude constante, de vitesse linéaire non nécessairement constante voulant rejoindre une trajectoire circulaire de rayon de courbure minimum.Le deuxième problème concerne une approche inverse du contrôle optimal. Il s’agit d’élaborer des méthodes théoriques de reconstruction du critère optimisé dans un problème de contrôle optimal à partir d’un ensemble de solutions à ce problème, ainsi que caractériser les "bons" ensembles de trajectoires permettant la reconstruction du critère. Le contrôle optimal inverse connait un regain d’intérêt depuis une quinzaine d’années, en particulier dans l’étude des comportements moteurs humains. En effet, selon un paradigme largement accepté en neurophysiologie, parmi tous les mouvements possibles ceux effectivement réalisés sont solutions d’un processus d’optimisation.Le troisième problème traite de stabilisation par retour de sortie. Nous analysons, à travers un exemple académique tiré du contrôle quantique, le problème de stabilisation par retour de sortie (à l’aide d’un observateur) lorsque le point où l'on souhaite stabiliser le système correspond à un contrôle qui rend le système inobservable. L’idée générale est de perturber le retour d’état stabilisant afin de garantir l’observabilité du système tout en stabilisant le système sur la cible. L’analyse de cet exemple académique nous permet dans un second temps de dégager une méthode générale pouvant s’appliquer à une classe de système beaucoup plus large. / The overall context of this thesis is the study of inverse and direct problems in control theory. More specifically, the following three problems are studied.The first one is an optimal control problem (direct approach). The aim is to give a time minimum systhesis fora kinematic model of a UAV flying at constant altitude with positive (non-necessarily constant) linear velocityin order to steer it to a fixed circle of minimum turning radius.The second problem deals with an inverse approach of optimal control. The aim is to develop theoretical methods in order to reconstruct the minimized criterion in an optimal control problem from a set of solution to this problem. The aim is also to characterize the « good » sets of trajectories leading to the reconstruction of the criterion. In the last fifteen years, there has been a renewed interest in inverse optimal control, especially inhuman motor behavior. Indeed, according to a well accepted paradigm in neurophysiology, among all possible movements, those actually accomplished are solutions of an optimization process.The third problem tackles output feedback stabilization. We analyze, via a simple academic example from quantum control, the problem of dynamic output feedback stabilization, when the point where we want to stabilize corresponds to a control value that makes the system unobservable. The general idea is to perturb the stabilizing state feedback in order to ensure the observability of the system while stabilizing it to the target.The analysis of this example allows, secondly, to identify a general procedure that can be applied to a widerclass of systems.
874

Compositional and Structural Properties of Emulsion-Treated Base Material: 7800 South in West Jordan, Utah

Gurney, Lisa Renay 21 June 2013 (has links)
The objectives of this research were 1) to examine correlations between compositional and structural properties of emulsion-treated base (ETB) layers, determine which of these factors exhibit the greatest spatial variability, and determine if significant differences exist between different test sections on a given project and 2) to investigate temporal trends in the structural properties of base materials treated with asphalt emulsion and to assess the rate at which ETB design properties are achieved. The research conducted in this study focused on testing of the ETB layer constructed on 7800 South (SR-48) in West Jordan, Utah. The research conducted in this study involved field and laboratory evaluations of spatial and temporal variability in properties of ETB. Regarding spatial results, the average modulus values of the ETB layer were unusually low for a typical stabilized base material and were in general even lower than the subgrade modulus values at this test site. All three sections had high moisture contents after compaction, with the moisture content of the ETB layer exceeding the specified optimum moisture content at many locations even before the emulsion was injected. One of the three test sections had higher percentages of reclaimed asphalt pavement and emulsion than the other two. The ETB compressive strength was very low throughout the entire year of testing, clearly demonstrating the consequences of inadequate emulsion curing associated with this project. The statistical analyses showed that higher pre-treatment moisture contents and higher amounts of binder added were associated with lower stiffness and strength, while higher wet densities were associated with higher stiffness and strength. The analyses also showed substantial variation in most response variables but comparatively low variation in predictor variables. Only four structural properties were significantly different between sections. Temporal testing was performed to monitor the properties of the ETB layer and to compare the ETB section to an adjacent untreated base course (UTBC) section. The ETB moisture content did not change significantly during the 1-year monitoring period, showing that drying of the ETB layer did not occur following placement of the hot mix asphalt surface. Furthermore, the analyses provided no evidence that the ETB layer experienced any sustained increase in strength as a result of emulsion curing; instead, the ETB modulus was shown to be greatly dependent on season, with higher ETB moisture contents and temperatures corresponding to lower ETB modulus values. Even during the winter when the ETB stiffness reached its peak, the modulus was still below the target value specified for this project. The statistical analyses indicated that the modulus values of the ETB and UTBC layers were not statistically different.
875

On reliable and scalable management of wireless sensor networks

Bapat, Sandip Shriram, January 2006 (has links)
Thesis (Ph. D.)--Ohio State University, 2006. / Title from first page of PDF file. Includes bibliographical references (p. 164-170).
876

Differential Regulation of Steroid Receptors in Breast Cancer by the Rho GEF Vav3

McCarrick, Jessica Anne 01 January 2008 (has links)
Recently reported data demonstrate that Vav3, a Rho Guanine Nucleotide Exchange Factor (Rho GEF) is overexpressed in breast tumors, coexpressed with ER, necessary for proliferation in breast cancer cells, and predictive of response to neoadjuvant endocrine therapies in patients with ER+ tumors. Such data beg the question as to what roles Vav3 plays in modulation of steroid receptor activity in breast cancer and in resistance to current hormonal therapies. Using reporter assays, I provide novel evidence that Vav3 potentiates Estrogen Receptor activity and represses Androgen Receptor activity in breast cancer cells. Vav3 potentiates ligand-dependent estrogen receptor activity in the MCF-7. A truncated, constitutively active form of Vav3, caVav3 potentiates ligand dependent ER activity in both MCF-7 and T47D. Vav3 activates Rho GTPases through its GEF domain. ER potentiation by caVav3 is dependent upon GEF activity. A caVav3 mutant with defective GEF function represses basal and ligand-mediated ER activity in T47D. Although other studies have shown that Vav3 could activate various Rho GTPases, only constitutively active Rac1 mutants potentiated ER activity in both cell lines. Contrastingly, reporter assays were used to show that caVav3 inhibits ligand-mediated AR activity in the AR+ T47D cell line by both R1881 and DHT stimulation. caVav3-mediated repression of AR activity is GEF-dependent, as caVav3 GEF mutants potentiate AR activity. Constitutively active forms of Rho GTPases were found to repress AR activity to different extents, but R1881-mediated AR activity was only significantly repressed by caCdc42. My studies of the effect of androgens on AR protein by western blot show that androgens downregulate AR protein in the highly Vav3 positive T47D cell line. Previous studies have demonstrated that androgens stabilize AR protein in MCF-7, and I now provide evidence that overexpression of Vav3 or caVav3 reverses hormone-mediated AR protein stabilization in MCF-7. These data are especially relevant given recently published data that decreased AR protein levels contributed to failure of response to MPA in patients with metastatic breast cancer. Further breast cancer studies may prove Vav3 to be a potential drug target in hormone dependent, hormone independent, and metastatic disease.
877

Computational Techniques for Coupled Flow-Transport Problems

Kronbichler, Martin January 2011 (has links)
This thesis presents numerical techniques for solving problems of incompressible flow coupled to scalar transport equations using finite element discretizations in space. The two applications considered in this thesis are multi-phase flow, modeled by level set or phase field methods, and planetary mantle convection based on the Boussinesq approximation. A systematic numerical study of approximation errors in evaluating the surface tension in finite element models for two-phase flow is presented. Forces constructed from a gradient in the same discrete function space as used for the pressure are shown to give the best performance. Moreover, two approaches for introducing contact line dynamics into level set methods are proposed. Firstly, a multiscale approach extracts a slip velocity from a micro simulation based on the phase field method and imposes it as a boundary condition in the macro model. This multiscale method is shown to provide an efficient model for the simulation of contact-line driven flow. The second approach combines a level set method based on a smoothed color function with a the phase field method in different parts of the domain. Away from contact lines, the additional information in phase field models is not necessary and it is disabled from the equations by a switch function. An in-depth convergence study is performed in order to quantify the benefits from this combination. Also, the resulting hybrid method is shown to satisfy an a priori energy estimate. For the simulation of mantle convection, an implementation framework based on modern finite element and solver packages is presented. The framework is capable of running on today's large computing clusters with thousands of processors. All parts in the solution chain, from mesh adaptation over assembly to the solution of linear systems, are done in a fully distributed way. These tools are used for a parallel solver that combines higher order time and space discretizations. For treating the convection-dominated temperature equation, an advanced stabilization technique based on an artificial viscosity is used. For more efficient evaluation of finite element operators in iterative methods, a matrix-free implementation built on cell-based quadrature is proposed. We obtain remarkable speedups over sparse matrix-vector products for many finite elements which are of practical interest. Our approach is particularly efficient for systems of differential equations.
878

An Application of Multiple Regression in Exchange Rate Arrangements.

Ndiritu, Gachiri Charles. January 2008 (has links)
<p>This project &quot / An application of multiple regression in exchange rate arrangement&quot / focused on the processes followed by different countries when choosing an exchange rate regime for currency stabilization. It analyses the consequences faced by emerging markets as a result of changes in volatility of developed countries&rsquo / currencies (American Dollar, Japanese Yen, EURO, British Pound and the Canadian Dollar).</p>
879

Engineering Proteinaceous Ligands for Improved Performance in Affinity Chromatography Applications

Gülich, Susanne January 2002 (has links)
No description available.
880

Varying data quality and effects in economic analysis and planning

Eklöf, Jan A. January 1992 (has links)
Economic statistics are often taken as given facts, assumed to describe exactly, actual phenomena in society. Many economic series are published in various forms from preliminary, via revisions to definitive estimates. Preliminary series are issued for a number of central economic processes in order to allow for rapid, up-to-date signals. This dissertation focuses on qualitative aspects of available data, and effects of possible inaccuracy when data are used for economic modelling, analysis and planning. Four main questions are addressed: How to characterize quality of data for central economic time series? What effects may possible inaccuracies in data have when used in econometric modelling? What effects do inaccuracies and errors in data have when models are used for economic analysis and planning? Is it possible to specify a criterion for deciding the cost-effective quality of data to be produced as input for economic policy analysis? The various realizations of economic variables often show considerable systematic as well as stochastic discrepancies for the same quantity. Preliminary series are generally found to be of questionable quality, but still considerably better than simple trend forecasts. Compared with the situation in a few other industrialized countries, the variability of Swedish economic statistics is, though, not extraordinary. Illustrations of effects of using inaccurate data, especially of combining preliminary, revised and definitive observations in the same model, are presented. Such inconsistent combinations of various realizations are in actual fact found in many open sources. Inclusion of preliminary series tends to indicate stronger changes in the economy than when definite observations are used throughout. The study is concluded with a section on cost-benefit aspects of economic statistics, and a sketch model for appraising data of variable quality is proposed. / Diss. Stockholm : Handelshögsk.

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