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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.
161

Detection of specific steady-state visual evoked potentials when multiple frequencies are available for simulation

Schenk, Eric R. January 1998 (has links)
No description available.
162

5-sparse steiner triple systems

Wolfe, Adam J. 04 August 2005 (has links)
No description available.
163

Resilience in an Urban Social Space: A Case Study of Wenceslas Square

Anderson, Cynthia E. 21 March 2011 (has links)
No description available.
164

DATA FITTING AND LEAST-SQUARE ESTIMATION OF NONLINEAR PARAMETERS FOR MODELS OF DIELECTRIC RELAXATION DATA

Zou, Hai 06 1900 (has links)
<p> The work in this thesis is to develop a tool for calculating the parameters corresponding to certain theoretical model of dielectric relaxation phenomena and then doing the curve fitting using the result after fetching the data from the user. To our best knowledge, this the first such tool to calculate the parameters corresponding to certain theoretical model of dielectric relaxation phenomena while the user only need to provide the experimental data. The parameters are calculated by using a nonlinear least square algorithm implemented in Matlab and a nonlinear function minimizer available in Matlab. The way to do the curve fitting is not by the traditional way such as cubic spline but by calculating the simulated data using the chosen model and the calculated result for the parameters. </p> <p> The available mathematical models include all of popular theoretical models, the Cole-Davidson (DC), the Kohlrausch-Williams-Watts (KWW), the Havriliak-Negami (HN) and the model proposed by R. Hilfer (FD). </p> <p> There are two ways to calculate the parameters for each model as mentioned before. The result returned by this system may not be unique. Especially if the frequency range of data is not wide enough, the result would most likely be non-unique. Since the iterative method is used in the system, it is suggested that the user provides the initial values for the system with his best knowledge or background for the data and the tested sample related to dielectric relaxation process. </p> <p> It is normal if there is a part having worse fitting than the other parts. One of reasons could be the mathematical model's defect, which the model does not work for that part. For the further information, please contact me by email at zouhaijun at yahoo.com. </p> / Thesis / Master of Science (MSc)
165

The Effect of Fins on Fluidelastic Instability in In-Line and Rotated Square Tube Arrays

Lumsden, Robert January 2008 (has links)
The study of fluidelastic instability in tube arrays has been ongoing for four decades. Although much research has been conducted, a full understanding of the mechanisms involved is still not available. Designers of cross-flow heat exchangers must depend on experience and empirical data from laboratory studies. As new designs are developed, which differ from these experimental facilities, there is an increased risk of failure due to fluidelastic instability. An experimental program was conducted to examine fluidelastic instability in inline and rotated square finned tube arrays. Three arrays of each geometry type were studied; two with serrated, helically wound finned tubes of different fin densities, and the third, a bare tube which had the same base diameter as the finned tubes. The tube pitch was kept constant to reduce the number of test sections required under this investigation. As a result, the bare tube array has a larger tube pitch ratio than that of previous researchers. The finned tubes under consideration were commercial fmned tubes of a type typically used in the fossil and process industries. The addition of fins to tubes in heat exchangers enhances heat transfer due to the increased surface area and the turbulence produced by the flow moving over the fins. The resulting flow pattern/distribution due to the fins is therefore much more complicated than in bare tube arrays. Previous research has shown that an effective diameter of a finned tube is useful in the prediction of vortex shedding. This concept is used to compare the finned tube results with the existing bare tube array guidelines for fluidelastic instability. All of the tube arrays in the present study have the same tube pitch, and have been scaled to have the same mass ratio. Results for the rotated square arrays show that the use of an effective diameter is beneficial in the scaling of fluidelastic instability and the finned tube results are found to fit within the scatter of the existing data for fluidelastic instability. For in-line square arrays, the results indicate that fins significantly increase the stability threshold. / Thesis / Master of Applied Science (MASc)
166

Holding Court in Old Town: A New Courthouse for Alexandria

Moore, Talia Renee 10 June 2024 (has links)
In the United States, the preeminent ideal concerning the justice system is that all people are innocent until proven guilty. The reality of the system, however, is not so cut and dry. Biases, mental health crises, and inequity all play a part in creating unjust circumstances for those accused of a crime. What role does architecture have to play in the judicial system? The architecture of our courthouses communicates that people are guilty until proven innocent. Movement through the courts is highly choreographed, creating a rigidity and hierarchy that encourages an us-them mentality and fosters a sense of "otherness." What does that communicate to the judge or jury–that this person is less than human? Our modern courtroom form is rooted in Roman basilica form, as judicial proceedings would happen there. It is a highly theatrical, highly structured space with a hierarchy built up in elevation–placing different levels of value on individuals. What would a courtroom look like where everyone, even though they have varying amounts of power based on their respective roles, sees eye to eye? What is the role of architecture in this question? My goal is to design a courtroom and resulting courthouse where, for the duration of the proceedings, everyone has the same level of perceived humanity. / Master of Architecture / In the United States, the preeminent ideal concerning the justice system is that all people are innocent until proven guilty. The reality of the system, however, is not so cut and dry. Biases, mental health crises, and inequity all play a part in creating unjust circumstances for those accused of a crime. What role does architecture have to play in the judicial system? The architecture of our courthouses communicates that people are guilty until proven innocent. Movement through the courts is highly choreographed, creating a rigidity and hierarchy that encourages an us-them mentality and fosters a sense of "otherness." What does that communicate to the judge or jury–that this person is less than human? I am exploring all of these questions and more in my thesis. The proposed building will replace the Alexandria, Virginia Courts building on King Street, which currently hides behind an office building and embodies the rigidity and secrecy of the judicial process. The new courts building emphasizes transparency, streamlines movement, and reimagines the courtroom as a place where people gather at a table.
167

Sequential analysis of categorical data

Kent, James Richard January 1962 (has links)
Using a variance-stabilizing transformation of the non-centralχ² distribution and Wald's sequential probability ratio test, procedures have been developed for sequential analysis of categorical data group-wise. These procedures' enables (i) a simple hypothesis to be used for the alternative hypothesis instead of the composite hypothesis commonly used in goodness-of-fit tests, contingency tables, and Mood's non-parametric generalization of the one-way analysis of variance, (ii) calculation or a power function, and (iii) calculation of the greatest expected ASR's and the non-centrality parameter requiring this sample size in addition to the ASN's when the null or alternative hypothesis is true. Application of these procedures to the three types of analysis given in (i) give the right decisions with sample sizes near the calculated ASN’s. The ASN's for when the expected number of groups equals one compare favorably with those obtained by Jackson (1959) using Bhate’s conjecture and those obtained empirically by Appleby (1960). In general, the sequential approach will require smaller sample sizes than fixed sampling if the non-centrality parameter is equal to or less than the group size and the group size is large enough to meet minimum expectation requirements. / M.S.
168

The influence of cotton technology on plant based scouting methods and performance of commonly used insecticides for tarnished plant bug (Hemiptera: Miridae)prior to bloom in Mississippi cotton

Huoni, James Michael, Jr. 10 May 2024 (has links) (PDF)
The focus of this research was to evaluate commonly used insecticides and plant based scouting practices in cotton, Gossypium hirsutum (L.), prior to bloom for tarnished plant bug, Lygus lineolaris (Palisot de Beauvois), management. As well as determine the influence of ThryvOn technology on these research objectives. Data indicate that imidacloprid may have a limited fit in non-ThryvOn cotton, while the additional mode of action afforded by ThryvOn technology could extend imidacloprid and other insecticide’s effective use prior to bloom. Additionally, sulfoxaflor and acephate remain the best products for pre-bloom management. When evaluating differences between plant based scouting methods prior to bloom used among cotton consultants across the Mid-Southern region, cotton technology and tarnished plant bug control did not cause variability in square retention monitoring methods, while sample date, or cotton growth did. However, based off these results, plant-based extension scouting recommendations do not need altering at this time.
169

Frottement en hydroformage de tube : caractérisation du frottement par le test d'expansion en matrice carrée / Friction tube hydroforming process : friction characterization by pure expansion test in a square section die

Abdelkefi, Abir 21 July 2016 (has links)
L’objectif de cette thèse est d’étudier la possibilité de caractériser le coefficient de frottement par un modèle analytique. Tout d’abord, le modèle analytique (Orban-Hu,2007) a été programmé à l’aide du logiciel « Matlab » puis validé par simulation numérique à l’aide du logiciel « Ls-Dyna ». Ensuite, on a réalisé des essais expérimentaux afin de caractériser les propriétés mécaniques du cuivre d’une part et étudier la mise en forme de tubes par hydroformage de tubes. Par suite, le coefficient de frottement a été caractérisé aussi bien par le modèle analytique que par le test classique ‘pion sur disque’. Les simulations numériques avec les coefficients de frottement obtenus ont permis de valider les résultats issus des essais expérimentaux pour une matrice carrée. Les mêmes résultats ont été également obtenus pour d’autres configurations géométriques (section rectangulaire, trapézoïdale et trapèze.) / The objective of this thesis is to study the possibility of characterizing the friction coefficient by an analytical model. First, the analytical model (Orban-Hu, 2007) has been programmed using "Matlab» software and has been validated by numerical simulation using "LS-Dyna" software. Then, experimental tests were carried out in order i) to characterize the mechanical properties of copper and ii) to study the tube hydroforming in a square section. As a result, the friction coefficient was characterized by the analytical model and the pin-on-disk test. Then, the numerical simulation with the friction coefficients obtained allowed to validate the experimental results for a square section. The same findings were obtained using other die geometries (rectangular, trapezoidal and trapezoid-sectional die).
170

Error Structure of Randomized Design Under Background Correlation with a Missing Value

Chang, Tseng-Chi 01 May 1965 (has links)
The analysis of variance technique is probably the most popular statistical technique used for testing hypotheses and estimating parameters. Eisenhart presents two classes of problems solvable by the analysis of variance and the assumption underlying each class. Cochran lists the assumptions and also discusses the consequences when these assumptions are not met. It is evident that if all the assumptions are not satisfied, the confidence placed in any result obtained in this manner is adversely affected to varying degrees according to the extent of the violation. One of the assumptions in the analysis of variance procedures is that of uncorrelated errors. The experimenter may not always meet this conditions because of economical or environmental reasons. In fact, Wilk questions the validity of the assumption of uncorrelated errors in any physical situation. For example, consider an experiment over a sequence of years. A correlation due to years may exist, no matter what randomization technique is used, because the outcome of the previous year determines to a great extent the outcome of this year. Another example would be the case of selecting experimental units from the same source, such as, sampling students with the same background or selecting units from the same production process. This points out the fact that the condition such as background, or a defect in the production process may have forced a correlation among the experimental units. Problems of this nature frequently occur in Industrial, Biological, and Psychological experiments.

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