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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.
71

Isometries and CAT (0) metric spaces /

Wolfson, Naomi Lynne, January 1900 (has links)
Thesis (M.Sc.) - Carleton University, 2006. / Includes bibliographical references (p. 162-164). Also available in electronic format on the Internet.
72

Geometry of Banach spaces and some fixed point theorems. --

Yadav, Raj Kishore. January 1972 (has links)
Thesis (M.A.) -- Memorial University of Newfoundland. / Typescript. Bibliography : leaves 97-105. Also available online.
73

Bitopological spaces, compactifications and completions

Salbany, Sergio. January 1974 (has links)
Originally presented as the author's thesis, University of Cape Town, 1970. / Includes bibliographical references (p. 97-99).
74

Classical trees and compact ultrametric spaces

Mirani, Mozhgan. January 2006 (has links)
Thesis (Ph. D. in Mathematics)--Vanderbilt University, May 2006. / Title from title screen. Includes bibliographical references.
75

Fuzzy metric spaces and applications to perceptual colour-differences

Miñana Prats, Juan José 21 May 2015 (has links)
[EN] Fuzzy mathematics has constituted a wide field of research, since L. A. Zadeh introduced in 1965 the concept of fuzzy set. In particular, the problem of constructing a satisfactory theory of fuzzy metric spaces has been investigated by several authors. In 1994, George and Veeramani introduced and studied a notion of fuzzy metric space that constituted a modification of the one given by Kramosil and Michalek. Several authors have contributed to the study of this kind of fuzzy metrics, from the mathematical point of view and for their applications. In this thesis we have contributed to develop the study of these fuzzy metrics, from the mathematical point of view, and we approached the problem of measuring perceptual colour-difference between samples of colour using one of these fuzzy metrics. The contributions of the study carried out in this thesis is summarized as follows: \begin{enumerate} \item[(i)] We have made a detailed study of the fuzzy metric space $(X,M,\cdot)$ where $M$ is given on $X=[0,\infty[$ by $M(x,y,t)=\frac{\min\{x,y\}+t}{\max\{x,y\}+t}$ and others related to it. As a consequence we have introduced five questions in fuzzy metrics related to continuity, extension, contractivity and completion. \item[(ii)] We have answered an open question constructing a fuzzy metric space $(X,M,\ast)$ in which the assignment $f(t)=\lim_n M(a_n,b_n,t)$, where $\{a_n\}$ and $\{b_n\}$ are $M$-Cauchy sequences in $X$, is not a continuous function on $t$. The response to this question has allowed us to characterize the class of completable strong fuzzy metric spaces. \item[(iii)] We have introduced and studied a stronger concept than convergence of sequences in fuzzy metric spaces, which we call $s$-convergence. In our study, we have gotten a characterization of those spaces in which every convergent sequence is $s$-convergent and we have given a classification of fuzzy metrics attending to the behaviour of the fuzzy metric with respect to the different types of convergence. \item[(iv)] We have studied, in the context of fuzzy metric spaces, when certain families of open balls centered at a point are local bases for this point. \item[(v)] We have answered two open questions related to standard convergence, a stronger concept than convergence of sequences in fuzzy metric spaces, introduced in a natural way attending to the concept of standard Cauchy sequence (introduced in \cite{adomain}). These responses have led us to establish conditions under which Cauchyness and convergence should be considered \textit{compatible}. \item[(vi)] As a practical application, we have shown that a certain fuzzy metric is useful for measuring perceptual colour-differences between colour samples. \end{enumerate} / [ES] La matemática fuzzy ha constituido un amplio campo en la investigación, desde que en 1965 L. A. Zadeh introdujo el concepto de conjunto fuzzy. En particular, la construcción de una teoría satisfactoria de espacios métricos fuzzy ha sido un problema investigado por muchos autores. En 1994, George y Veeramani introdujeron y estudiaron una noción de espacio métrico fuzzy que constituía una modificación de la anteriormente dada por Kramosil y Michalek. Muchos autores han contribuido al estudio de este tipo de métricas fuzzy, desde el punto de vista matemático y de sus aplicaciones. En esta tesis hemos contribuido al desarrollo del estudio de estas métricas fuzzy, desde el punto de vista matemático, y hemos abordado el problema de la medida de la diferencia perceptual de color utilizando una de estas métricas. Las contribuciones que aportamos en esta tesis a dicho estudio, se resumen a continuación: \begin{enumerate} \item[(i)] Hemos hecho un estudio detallado del espacio métrico fuzzy $(X,M,\cdot)$ donde $M$ está dada sobre $[0,\infty[$ por la expresión $M(x,y,t)=\frac{\min\{x,y\}+t}{\max\{x,y\}+t}$ y de otros espacios métricos fuzzy relacionados con el. Como consecuencia de este estudio hemos introducido cinco cuestiones en la teoría de las métricas fuzzy relacionadas con continuidad, extensión, contractividad y completación. \item[(ii)] Hemos respondido a una cuestión abierta construyendo un espacio métrico fuzzy $(X,M,\ast)$ en el cual la asignación $f(t)=\lim_n M(a_n,b_n,t)$, donde $\{a_n\}$ y $\{b_n\}$ son sucesiones $M$-Cauchy, no es una función continua sobre $t$. La respuesta a esta cuestión nos ha permitido caracterizar la clase de los espacios métricos fuzzy strong completables. \item[(iii)] Hemos introducido y estudiado un concepto más fuerte que el de convergencia de sucesiones en espacios métricos fuzzy, al que hemos llamado $s$-convergencia. En nuestro estudio hemos conseguido una caracterización de aquellos espacios métricos fuzzy en los cuales toda sucesión convergente es $s$-convergente y hemos dado una clasificación de los espacios métricos fuzzy atendiendo a su comportamiento con respecto a los diferentes tipos de convergencia que se da en él. \item[(iv)] Hemos estudiado, en el contexto de los espacios métricos fuzzy, cuando ciertas familias de bolas abiertas centradas en un punto son base local de este punto. \item[(v)] Hemos respondido a dos cuestiones abiertas relacionadas con la convergencia standard, un concepto más fuerte que el de convergencia de sucesiones en espacios métricos fuzzy, introducido de forma natural a partir del concepto de sucesión de Cauchy standard (introducido en \cite{adomain}). Estas respuestas nos han llevado a establecer unas condiciones bajo las cuales un concepto relacionado con el concepto de sucesión de Cauchy y un concepto relacionado con el de convergencia deberían satisfacer para ser consideradas \textsl{compatibles}. \item[(vi)] Como aplicación práctica, hemos mostrado que una cierta métrica fuzzy es útil para medir diferencia perceptual de color entre muestras de color. \end{enumerate} / [CAT] La matemàtica fuzzy ha constituït un ampli camp en la investigació, des que el 1965 L. A. Zadeh va introduir el concepte de conjunt fuzzy. En particular, la construcció d'una teoria satisfactòria d'espais mètrics fuzzy ha estat un problema investigat per molts autors. El 1994, George i Veeramani introduiren i estudiaren una noció d'espai mètric fuzzy que constituïa una modificació de la donada per Kramosil i Michalek anteriorment. Molts autors han contribuït a l'estudi d'aquest tipus de mètriques fuzzy, des del punt de vista matemàtic i de les seves aplicacions. En aquesta tesi hem contribuït al desenvolupament de l'estudi d'aquestes mètriques fuzzy, des del punt de vista matemàtic, i hem abordat el problema de la mesura de la diferència perceptiva de color utilitzant aquestes mètriques. Les contribucions que aportem en aquesta tesi a tal estudi es resumeixen a continuació: \begin{enumerate} \item[(i)] Hem fet un estudi detallat de l'espai mètric fuzzy $(X,M,\cdot)$ on $M$ està donada sobre $[0,\infty[$ per l'expressió $M(x,y,t)=\frac{\min\{x,y\}+t}{\max\{x,y\}+t}$ i d'altres espais mètrics fuzzy relacionats amb ell. Com a conseqüència d'aquest estudi hem introduït cinc qüestions en la teoria de les mètriques fuzzy relacionades amb continuïtat, extensió, contractividad i completació. \item[(ii)] Hem respost a una qüestió oberta construint un espai mètric fuzzy $ (X, M, \ast) $ en el qual l'assignació $ f (t) = \lim_n M (a_n, b_n, t) $, on $ \{a_n\} $ i $ \{b_n \} $ són successions $ M $-Cauchy, no és una funció contínua sobre $ t $. La resposta a aquesta qüestió ens ha permès caracteritzar la classe dels espais mètrics fuzzy strong completables. \item[(iii)] Hem introduït i estudiat un concepte més fort que el de convergència de successions en espais mètrics fuzzy, al qual hem anomenat $ s $-Convergència. En el nostre estudi hem aconseguit una caracterització d'aquells espais mètrics fuzzy en els quals tota successió convergent és $ s $-convergente i hem donat una classificació dels espais mètrics fuzzy atenent al seu comportament respecte als diferents tipus de convergència que es dóna en ell. \item[(iv)] Hem estudiat, en el context dels espais mètrics fuzzy, quan certes famílies de boles obertes centrades en un punt són base local d'aquest punt. \item[(v)] Hem respost a dues qüestions obertes relacionades amb la convergència estàndard, un concepte més fort que el de convergència de successions en espais mètrics fuzzy, introduït de forma natural a partir del concepte de successió de Cauchy estàndard (introduït en \cite{adomain}). Aquestes respostes ens han portat a establir unes condicions sota les quals un concepte relacionat amb el concepte de successió de Cauchy i un concepte relacionat amb el de convergència haurien de satisfer per a ser considerats \textsl{compatibles}. \item[(vi)] Com a aplicació pràctica, hem mostrat que una certa mètrica fuzzy és útil per mesurar la diferència perceptiva de color entre mostres de color. \end{enumerate} / Miñana Prats, JJ. (2015). Fuzzy metric spaces and applications to perceptual colour-differences [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/50612 / TESIS
76

Dynamická metrika v OSPF sítích / Dynamic Metric in OSPF Networks

Mácha, Tomáš January 2016 (has links)
Masivní vývoj Internetu vedl ke zvýšeným požadavkům na spolehlivou síťovou infrastrukturu. Efektivita komunikace v síti závisí na schopnosti směrovačů určit nejlepší cestu pro odesílání a přeposílání paketů ke koncovému zařízení. Jelikož OSPF v současné době představuje jeden z nejpoužívanějších směrovacích protokolů, jakýkoli přínos, který by pomohl udržet krok s rychle se měnícím prostředí Internetu, je velmi vítán. Významným omezením OSPF protokolu je, mimo jiné, absence informovanosti algoritmu pro výpočet metriky o aktuálním vytížení linky. Tato vlastnost představuje tzv. slabé místo, což má negativní vliv na výkonnost sítě. Z tohoto důvodu byla navržena nová metoda založená na dynamické adaptaci měnících se síťových podmínek a alternativní strategii OSPF metrik. Navržená metoda řeší problém neinformovanosti OSPF metriky o síťovém provozu a nevhodně vytížených linek, které snižují výkonnost sítě. Práce rovněž přináší praktickou realizaci, kdy vlastnosti nové metody jsou testovány a ověřeny spuštěním testů algoritmu v reálných zařízeních.
77

Metric and Topological Approaches to Network Data Analysis

Chowdhury, Samir 03 September 2019 (has links)
No description available.
78

ANCIENT LIVES IN MOTION: A BIOARCHAEOLOGICAL EXAMINATION OF STABLE ISOTOPES, NONMETRIC TRAITS, AND HUMAN MOBILITY IN AN IMPERIAL ROMAN CONTEXT (1ST-3RD C. CE)

Stark, Robert James 06 1900 (has links)
This dissertation examines human mobility and population interactions at the Imperial Roman (ca. 1st–3rd c. CE) sites of Isola Sacra (SCR) at Portus, Velia in the Cilento of Italy, and Rue Jacques Brel Necropolis (JBR) in Saintes, France. Isotopes of oxygen (18Oc) and strontium (87Sr/86Sr) are used to assess instances of human mobility from the enamel of second molars (M2), providing a gauge of movement after age ~7–8 years. Nonmetric traits are employed in conjunction with isotopic perspectives to examine the nature of biological affinities and phenetic divergence between these three sites. Isotopic results of this study indicate that a significant number of individuals, including females and children, were mobile towards the sites at which they were ultimately interred, with the highest estimates of mobility provided by 18Oc seeing rates between 25%–38% across the three sites. 87Sr/86Sr results provided lower estimates of mobility ranging from zero cases at Velia to 30% at JBR, while combined 18Oc and 87Sr/86Sr analyses provided the lowest estimates of mobility ranging from zero cases at Velia to 20% at JBR. Such results suggest that a combined isotope approach may not necessarily increase the degree of mobility discrimination, bringing into question issues of regional homogeneity and overlap in 18Oc and 87Sr/86Sr values for the regions examined. A further examination of 18Oc variation in M1 vs. M2 vs. M3 for a sub-sample of 20 individuals indicates that childhood mobility was taking place at Portus. Nonmetric trait analysis provides insight to the nature of biological population similarity and divergence. Across the three sites SCR is the most similar to JBR and Velia, while Velia and JBR are the most dissimilar. The nature of these similarities suggests that overall the biological background of the people interred at JBR, SCR, and Velia is similar, but with unique regional phenetic differences indicating distinct biological populations at all three sites. Using these multiple lines of evidence this dissertation emphasizes a significant degree of mobility and population heterogeneity across the Roman landscape. It is evident from the research findings presented here that with the expanding Roman empire mobility and population interaction remained staples of Roman life. / Dissertation / Doctor of Philosophy (PhD)
79

Verification and validation using state of the art measures and modular uncertainty techniques

Weathers, James Boyd 03 May 2008 (has links)
As quantitative validation measures have become available, so has the controversy regarding the construction of such measures. The complexity of the physical processes involved is compounded by uncertainties introduced due to model inputs, experimental errors, and modeling assumptions just to name a few. Also, how these uncertainties are treated is of major importance. In this dissertation, the issues associated with several state of the art quantitative validation metrics are discussed in detail. Basic Verification and Validation (V&V) framework is introduced outlining areas where some agreement has been reached in the engineering community. In addition, carefully constructed examples are used to shed light on differences among the state of the art validation metrics. The results show that the univariate validation metric fails to account for correlation structure due to common systematic error sources in the comparison error results. Also, the confidence interval metric is an inadequate measure of the noise level of the validation exercise. Therefore, the multivariate validation metric should be utilized whenever possible. In addition, end-to-end examples of the V&V effort are provided using the multivariate and univariate validation metrics. Methodology is introduced using Monte Carlo analysis to construct the covariance matrix used in the multivariate validation metric when non-linear sensitivities exist. Also, the examples show how multiple iterations of the validation exercise can lead to a successful validation effort. Finally, modular uncertainty techniques are introduced for the uncertainty analysis of large systems where many data reduction equations or models are used to examine multiple outputs of interest. In addition, the modular uncertainty methodology was shown to be an equivalent method to the traditional propagation of errors approach with a drastic reduction in computational effort. The modular uncertainty technique also has the advantage in that insight is given into the relationship between the uncertainties of the quantities of interest being examined. An extension of the modular uncertainty methodology to cover full scale V&V exercises is also introduced.
80

Skylines in Metric Space

Fuhry, David P. 23 April 2008 (has links)
No description available.

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