Dissertations / Theses: 'Distributional'

1

Schluter, Christian. "Topics in distributional analysis : the importance of intermediate institutions for income distributions, inequality and intra-distributional mobility." Thesis, London School of Economics and Political Science (University of London), 1999. http://etheses.lse.ac.uk/1487/.

Full text

Abstract:

The unifying theme of this dissertation is the importance of intermediate institutions for income distributions, inequality and intra-distributional mobility. First, we analyse the effects of informational problems in a general equilibrium model with dynamically evolving wealth distributions. Poor agents need to borrow funds but a non-commitment problem on the capital market leads to persistent inequality. The next important institution to be examined is the tax-benefit system. The third chapter investigates the relative performance of alternative unemployment benefit regimes in a search-theoretic general equilibrium model of the labour market. Policy objectives such as the reduction in inequality or the alleviation of poverty are considered and the incentive problems are examined. Prior to the empirical analysis, the fourth chapter develops the large sample distribution of a number of inequality and mobility indices. Moreover, the relative performance of these (asymptotic) approximations and various bootstrap estimators is examined. The data is described in chapter five. The sixth chapter analyses the distributional consequences of the German tax-benefit system using the German Socio-Economic Panel. Two dimensions income dynamics are investigated by distinguishing between shape dynamics and intra-distributional mobility. The complementarity between various tools such as non-parametric stochastic kernel density estimates and transition matrices is explored. As the transition probabilities are found to be time-varying, several statistical models of income mobility are estimated (and a new mover-stayer model is proposed) in the last chapter. In order to give an economic explanation of the observed mobility patterns various duration models (with duration dependent hazards and unobserved heterogeneity) are estimated.

APA, Harvard, Vancouver, ISO, and other styles

2

King, Robert Arthur Ravenscroft. "New distributional fitting methods applied to the generalised [lambda] distribution." Thesis, Queensland University of Technology, 1999.

Find full text

APA, Harvard, Vancouver, ISO, and other styles

3

Haili, Hailiza Kamarul. "Distributional problems in arithmetic." Thesis, University of Liverpool, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.366245.

Full text

APA, Harvard, Vancouver, ISO, and other styles

4

Baker, Kirk. "Multilingual Distributional Lexical Similarity." The Ohio State University, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=osu1221752517.

Full text

APA, Harvard, Vancouver, ISO, and other styles

5

Trenn, Stephan. "Distributional differential algebraic equations." Ilmenau Univ.-Verl, 2009. http://d-nb.info/99693197X/04.

Full text

APA, Harvard, Vancouver, ISO, and other styles

6

Bilyk, Dmytro. "Distributional estimates for multilinear operators." Diss., Columbia, Mo. : University of Missouri-Columbia, 2005. http://hdl.handle.net/10355/4139.

Full text

Abstract:

Thesis (Ph. D.)--University of Missouri-Columbia, 2005.
The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file viewed on (May 23, 2006) Vita. Includes bibliographical references.

APA, Harvard, Vancouver, ISO, and other styles

7

Ratko-Dehnert, Emil. "Distributional constraints on cognitive architecture." Diss., Ludwig-Maximilians-Universität München, 2013. http://nbn-resolving.de/urn:nbn:de:bvb:19-159387.

Full text

Abstract:

Mental chronometry is a classical paradigm in cognitive psychology that uses response time and accuracy data in perceptual-motor tasks to elucidate the architecture and mechanisms of the underlying cognitive processes of human decisions. The redundant signals paradigm investigates the response behavior in Experimental tasks, where an integration of signals is required for a successful performance. The common finding is that responses are speeded for the redundant signals condition compared to single signals conditions. On a mean level, this redundant signals effect can be accounted for by several cognitive architectures, exhibiting considerable model mimicry. Jeff Miller formalized the maximum speed-up explainable by separate activations or race models in form of a distributional bound – the race model inequality. Whenever data violates this bound, it excludes race models as a viable account for the redundant signals effect. The common alternative is a coactivation account, where the signals integrate at some stage in the processing. Coactivation models have mostly been inferred on and rarely explicated though. Where coactivation is explicitly modeled, it is assumed to have a decisional locus. However, in the literature there are indications that coactivation might have at least a partial locus (if not entirely) in the nondecisional or motor stage. There are no studies that have tried to compare the fit of these coactivation variants to empirical data to test different effect generating loci. Ever since its formulation, the race model inequality has been used as a test to infer the cognitive architecture for observers’ performance in redundant signals Experiments. Subsequent theoretical and empirical analyses of this RMI test revealed several challenges. On the one hand, it is considered to be a conservative test, as it compares data to the maximum speed-up possible by a race model account. Moreover, simulation studies could show that the base time component can further reduce the power of the test, as violations are filtered out when this component has a high variance. On the other hand, another simulation study revealed that the common practice of RMI test can introduce an estimation bias, that effectively facilitates violations and increases the type I error of the test. Also, as the RMI bound is usually tested at multiple points of the same data, an inflation of type I errors can reach a substantial amount. Due to the lack of overlap in scope and the usage of atheoretic, descriptive reaction time models, the degree to which these results can be generalized is limited. State-of-the-art models of decision making provide a means to overcome these limitations and implement both race and coactivation models in order to perform large scale simulation studies. By applying a state-of-the-art model of decision making (scilicet the Ratcliff diffusion model) to the investigation of the redundant signals effect, the present study addresses research questions at different levels. On a conceptual level, it raises the question, at what stage coactivation occurs – at a decisional, a nondecisional or a combined decisional and nondecisional processing stage and to what extend? To that end, two bimodal detection tasks have been conducted. As the reaction time data exhibits violations of the RMI at multiple time points, it provides the basis for a comparative fitting analysis of coactivation model variants, representing different loci of the effect. On a test theoretic level, the present study integrates and extends the scopes of previous studies within a coherent simulation framework. The effect of experimental and statistical parameters on the performance of the RMI test (in terms of type I errors, power rates and biases) is analyzed via Monte Carlo simulations. Specifically, the simulations treated the following questions: (i) what is the power of the RMI test, (ii) is there an estimation bias for coactivated data as well and if so, in what direction, (iii) what is the effect of a highly varying base time component on the estimation bias, type I errors and power rates, (iv) and are the results of previous simulation studies (at least qualitatively) replicable, when current models of decision making are used for the reaction time generation. For this purpose, the Ratcliff diffusion model was used to implement race models with controllable amount of correlation and coactivation models with varying integration strength, and independently specifying the base time component. The results of the fitting suggest that for the two bimodal detection tasks, coactivation has a shared decisional and nondecisional locus. For the focused attention experiment the decisional part prevails, whereas in the divided attention task the motor component is dominating the redundant signals effect. The simulation study could reaffirm the conservativeness of the RMI test as latent coactivation is frequently missed. An estimation bias was found also for coactivated data however, both biases become negligible once more than 10 samples per condition are taken to estimate the respective distribution functions. A highly varying base time component reduces both the type I errors and the power of the test, while not affecting the estimation biases. The outcome of the present study has theoretical and practical implications for the investigations of decisions in a multisignal context. Theoretically, it contributes to the locus question of coactivation and offers evidence for a combined decisional and nondecisional coactivation account. On a practical level, the modular simulation approach developed in the present study enables researchers to further investigate the RMI test within a coherent and theoretically grounded framework. It effectively provides a means to optimally set up the RMI test and thus helps to solidify and substantiate its outcomes. On a conceptual level the present study advocates the application of current formal models of decision making to the mental chronometry paradigm and develops future research questions in the field of the redundant signals paradigm.

APA, Harvard, Vancouver, ISO, and other styles

8

Curran, James Richard. "From distributional to semantic similarity." Thesis, University of Edinburgh, 2004. http://hdl.handle.net/1842/563.

Full text

Abstract:

Lexical-semantic resources, including thesauri and WORDNET, have been successfully incorporated into a wide range of applications in Natural Language Processing. However they are very difficult and expensive to create and maintain, and their usefulness has been severely hampered by their limited coverage, bias and inconsistency. Automated and semi-automated methods for developing such resources are therefore crucial for further resource development and improved application performance. Systems that extract thesauri often identify similar words using the distributional hypothesis that similar words appear in similar contexts. This approach involves using corpora to examine the contexts each word appears in and then calculating the similarity between context distributions. Different definitions of context can be used, and I begin by examining how different types of extracted context influence similarity. To be of most benefit these systems must be capable of finding synonyms for rare words. Reliable context counts for rare events can only be extracted from vast collections of text. In this dissertation I describe how to extract contexts from a corpus of over 2 billion words. I describe techniques for processing text on this scale and examine the trade-off between context accuracy, information content and quantity of text analysed. Distributional similarity is at best an approximation to semantic similarity. I develop improved approximations motivated by the intuition that some events in the context distribution are more indicative of meaning than others. For instance, the object-of-verb context wear is far more indicative of a clothing noun than get. However, existing distributional techniques do not effectively utilise this information. The new context-weighted similarity metric I propose in this dissertation significantly outperforms every distributional similarity metric described in the literature. Nearest-neighbour similarity algorithms scale poorly with vocabulary and context vector size. To overcome this problem I introduce a new context-weighted approximation algorithm with bounded complexity in context vector size that significantly reduces the system runtime with only a minor performance penalty. I also describe a parallelized version of the system that runs on a Beowulf cluster for the 2 billion word experiments. To evaluate the context-weighted similarity measure I compare ranked similarity lists against gold-standard resources using precision and recall-based measures from Information Retrieval, since the alternative, application-based evaluation, can often be influenced by distributional as well as semantic similarity. I also perform a detailed analysis of the final results using WORDNET. Finally, I apply my similarity metric to the task of assigning words to WORDNET semantic categories. I demonstrate that this new approach outperforms existing methods and overcomes some of their weaknesses.

APA, Harvard, Vancouver, ISO, and other styles

9

Barrachina, Civera Xavier. "Distributional chaos of C0-semigroups of operators." Doctoral thesis, Universitat Politècnica de València, 2013. http://hdl.handle.net/10251/28241.

Full text

Abstract:

El caos distribucional fue introducido por Schweizer y Smítal en [SS94] a partir de la noción de caos de Li-Yorke con el fín de implicar la entropía topológica positiva para aplicaciones del intervalo compacto en sí mismo. El caos distribucional para operadores fue estudiado por primera vez en [Opr06] y fue analizado en el contexto lineal de dimensión infinita en [MGOP09]. El concepto de caos distribucional para un operador (semigrupo) consiste en la existencia de un conjunto no numerable y un numero real positivo ¿ tal que para dos elementos distintos cualesquiera del conjunto no numerable, tanto la densidad superior del conjunto de iteraciones (tiempos) en las cuales la diferencia entre las órbitas de dichos elementos es mayor que ¿, como la densidad superior del conjunto de iteraciones (tiempos) en las cuales dicha diferencia es tan pequeña como se quiera, es igual a uno. Esta tesis est'a dividida en seis capítulos. En el primero, hacemos un resumen del estado actual de la teoría de la din'amica caótica para C0-semigrupos de operadores lineales. En el segundo capítulo, mostramos la equivalencia entre el caos distribucional de un C0-semigrupo y el caos distribucional de cada uno de sus operadores no triviales. Tambi'en caracterizamos el caos distribucional de un C0-semigrupo en t'erminos de la existencia de un vector distribucionalmente irregular. La noción de hiperciclicidad de un operador (semigrupo) consiste en la existencia de un elemento cuya órbita por el operador (semigrupo) sea densa. Si adem'as el conjunto de puntos periódicos es denso, diremos que el operador (semigrupo) es caótico en el sentido de Devaney. Una de las herramientas mas útiles para comprobar si un operador es hipercíclico es el Criterio de Hiperciclicidad, enunciado inicialmente por Kitai en 1982. En [BBMGP11], Bermúdez, Bonilla, Martínez-Gim'enez y Peris presentan elCriterio para Caos Distribucional (CDC en ingl'es) para operadores. Enunciamos y probamos una versión del CDC para C0-semigrupos. En el contexto de C0-semigrupos, Desch, Schappacher y Webb tambi'en estudiaron en [DSW97] la hiperciclicidad y el caos de Devaney para C0-semigrupos, dando un criterio para caos de Devaney basado en el espectro del generador in¿nitesimal del C0- semigrupo. En el tercer capítulo, establecemos un criterio de existencia de una variedad distribucionalmente irregular densa (DDIM en sus siglas en ingl'es) en t'erminos del espectro del generador in¿nitesimal del C0-semigrupo. En el Capítulo 4, se dan algunas condiciones su¿cientes para que el C0-semigrupo de traslación en espacios L p ponderados sea distribucionalmente caótico en función de la función peso admisible. Ademas, establecemos una analogía completa entre el estudio del caos distribucional para el C0-semigrupo de traslación y para los operadores de desplazamiento hacia atras o ¿backward shifts¿ en espacios ponderados de sucesiones. El capítulo quinto está dedicado al estudio de la existencia de C0-semigrupos para los cuales todo vector no nulo es un vector distribucionalmente irregular. Tambi'en damos un ejemplo de uno de dichos C0-semigrupos que además no es hipercíclico. En el Capítulo 6, el criterio DDIM se aplica a varios ejemplos de C0-semigrupos. Algunos de ellos siendo los semigrupos de solución de ecuaciones en derivadas parciales, como la ecuación hiperbólica de transferencia de calor o la ecuación de von Foerster-Lasota y otros son la solución de un sistema in¿nito de ecuaciones diferenciales ordinarias usado para modelizar la dinámica de una población de c'elulas bajo proliferación y maduración simultáneas.
Barrachina Civera, X. (2013). Distributional chaos of C0-semigroups of operators [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/28241
TESIS
Premiado

APA, Harvard, Vancouver, ISO, and other styles

10

Bjorgo, Kimberly A. "Distributional ecology of Kanawha River fish." Morgantown, W. Va. : [West Virginia University Libraries], 2006. https://eidr.wvu.edu/etd/documentdata.eTD?documentid=4814.

Full text

Abstract:

Thesis (Ph. D.)--West Virginia University, 2006.
Title from document title page. Document formatted into pages; contains vii, 195 p. : ill. (some col.), col. maps. Vita. Includes abstract. Includes bibliographical references.

APA, Harvard, Vancouver, ISO, and other styles

11

Mitchell, Jeffrey John. "Composition in distributional models of semantics." Thesis, University of Edinburgh, 2011. http://hdl.handle.net/1842/4927.

Full text

Abstract:

Distributional models of semantics have proven themselves invaluable both in cognitive modelling of semantic phenomena and also in practical applications. For example, they have been used to model judgments of semantic similarity (McDonald, 2000) and association (Denhire and Lemaire, 2004; Griffiths et al., 2007) and have been shown to achieve human level performance on synonymy tests (Landuaer and Dumais, 1997; Griffiths et al., 2007) such as those included in the Test of English as Foreign Language (TOEFL). This ability has been put to practical use in automatic thesaurus extraction (Grefenstette, 1994). However, while there has been a considerable amount of research directed at the most effective ways of constructing representations for individual words, the representation of larger constructions, e.g., phrases and sentences, has received relatively little attention. In this thesis we examine this issue of how to compose meanings within distributional models of semantics to form representations of multi-word structures. Natural language data typically consists of such complex structures, rather than just individual isolated words. Thus, a model of composition, in which individual word meanings are combined into phrases and phrases combine to form sentences, is of central importance in modelling this data. Commonly, however, distributional representations are combined in terms of addition (Landuaer and Dumais, 1997; Foltz et al., 1998), without any empirical evaluation of alternative choices. Constructing effective distributional representations of phrases and sentences requires that we have both a theoretical foundation to direct the development of models of composition and also a means of empirically evaluating those models. The approach we take is to first consider the general properties of semantic composition and from that basis define a comprehensive framework in which to consider the composition of distributional representations. The framework subsumes existing proposals, such as addition and tensor products, but also allows us to define novel composition functions. We then show that the effectiveness of these models can be evaluated on three empirical tasks. The first of these tasks involves modelling similarity judgements for short phrases gathered in human experiments. Distributional representations of individual words are commonly evaluated on tasks based on their ability to model semantic similarity relations, e.g., synonymy or priming. Thus, it seems appropriate to evaluate phrase representations in a similar manner. We then apply compositional models to language modelling, demonstrating that the issue of composition has practical consequences, and also providing an evaluation based on large amounts of natural data. In our third task, we use these language models in an analysis of reading times from an eye-movement study. This allows us to investigate the relationship between the composition of distributional representations and the processes involved in comprehending phrases and sentences. We find that these tasks do indeed allow us to evaluate and differentiate the proposed composition functions and that the results show a reasonable consistency across tasks. In particular, a simple multiplicative model is best for a semantic space based on word co-occurrence, whereas an additive model is better for the topic based model we consider. More generally, employing compositional models to construct representations of multi-word structures typically yields improvements in performance over non-compositonal models, which only represent individual words.

APA, Harvard, Vancouver, ISO, and other styles

12

Grave, Edouard. "A Markovian approach to distributional semantics." Phd thesis, Université Pierre et Marie Curie - Paris VI, 2014. http://tel.archives-ouvertes.fr/tel-00940575.

Full text

Abstract:

This thesis, which is organized in two independent parts, presents work on distributional semantics and on variable selection. In the first part, we introduce a new method for learning good word representations using large quantities of unlabeled sentences. The method is based on a probabilistic model of sentence, using a hidden Markov model and a syntactic dependency tree. The latent variables, which correspond to the nodes of the dependency tree, aim at capturing the meanings of the words. We develop an efficient algorithm to perform inference and learning in those models, based on online EM and approximate message passing. We then evaluate our models on intrinsic tasks such as predicting human similarity judgements or word categorization, and on two extrinsic tasks: named entity recognition and supersense tagging. In the second part, we introduce, in the context of linear models, a new penalty function to perform variable selection in the case of highly correlated predictors. This penalty, called the trace Lasso, uses the trace norm of the selected predictors, which is a convex surrogate of their rank, as the criterion of model complexity. The trace Lasso interpolates between the $\ell_1$-norm and $\ell_2$-norm. In particular, it is equal to the $\ell_1$-norm if all predictors are orthogonal and to the $\ell_2$-norm if all predictors are equal. We propose two algorithms to compute the solution of least-squares regression regularized by the trace Lasso, and perform experiments on synthetic datasets to illustrate the behavior of the trace Lasso.

APA, Harvard, Vancouver, ISO, and other styles

13

McGuinness, Graeme Colquhoun. "A distributional approach to fragmentation equations." Thesis, University of Strathclyde, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.435117.

Full text

APA, Harvard, Vancouver, ISO, and other styles

14

Batchkarov, Miroslav Manov. "Evaluating distributional models of compositional semantics." Thesis, University of Sussex, 2016. http://sro.sussex.ac.uk/id/eprint/61062/.

Full text

Abstract:

Distributional models (DMs) are a family of unsupervised algorithms that represent the meaning of words as vectors. They have been shown to capture interesting aspects of semantics. Recent work has sought to compose word vectors in order to model phrases and sentences. The most commonly used measure of a compositional DM's performance to date has been the degree to which it agrees with human-provided phrase similarity scores. The contributions of this thesis are three-fold. First, I argue that existing intrinsic evaluations are unreliable as they make use of small and subjective gold-standard data sets and assume a notion of similarity that is independent of a particular application. Therefore, they do not necessarily measure how well a model performs in practice. I study four commonly used intrinsic datasets and demonstrate that all of them exhibit undesirable properties. Second, I propose a novel framework within which to compare word- or phrase-level DMs in terms of their ability to support document classification. My approach couples a classifier to a DM and provides a setting where classification performance is sensitive to the quality of the DM. Third, I present an empirical evaluation of several methods for building word representations and composing them within my framework. I find that the determining factor in building word representations is data quality rather than quantity; in some cases only a small amount of unlabelled data is required to reach peak performance. Neural algorithms for building single-word representations perform better than counting-based ones regardless of what composition is used, but simple composition algorithms can outperform more sophisticated competitors. Finally, I introduce a new algorithm for improving the quality of distributional thesauri using information from repeated runs of the same non deterministic algorithm.

APA, Harvard, Vancouver, ISO, and other styles

15

Zagler, Martin. "Distributional consequences of capital tax coordination." SFB International Tax Coordination, WU Vienna University of Economics and Business, 2005. http://epub.wu.ac.at/906/1/document.pdf.

Full text

Abstract:

This paper has two ambitions. First, we review the economic literature on tax coordination. Second, we argue that the taxation of capital is not an issue of efficiency, but instead an issue of equity. In particular, capital tax coordination can alter the vertical distribution of income between the production factors capital and labour. Capital is in perfectly elastic supply in a small open economy. Therefore the tax incidence falls to the immobile factor, labour. By contrast, capital is in inelastic supply at the international level, and therefore the capital tax incidence falls completely on capital, without welfare losses of taxation. (author's abstract)
Series: Discussion Papers SFB International Tax Coordination

APA, Harvard, Vancouver, ISO, and other styles

16

Barry, Brendan(Brendan Cael). "Distributional models of ocean carbon export." Thesis, Massachusetts Institute of Technology, 2019. https://hdl.handle.net/1721.1/122321.

Full text

Abstract:

Thesis: Ph. D., Joint Program in Physical Oceanography (Massachusetts Institute of Technology, Department of Earth, Atmospheric, and Planetary Sciences; and the Woods Hole Oceanographic Institution), 2019
Cataloged from PDF version of thesis.
Includes bibliographical references (pages 137-153).
Each year, surface ocean ecosystems export sinking particles containing gigatons of carbon into the ocean's interior. This particle flux connects the entire ocean microbiome and constitutes a fundamental aspect of marine microbial ecology and biogeochemical cycles. Particle flux is also variable and intricately complex, impeding its mechanistic or quantitative description. In this thesis we pair compilations of available data with novel mathematical models to explore the relationships between particle flux and other key variables - temperature, net primary production, and depth. Particular use is made of (probability) distributional descriptions of quantities that are known to vary appreciably. First, using established thermodynamic dependencies for primary production and respiration, a simple mechanistic model is developed relating export efficiency (i.e. the fraction of primary production that is exported out of the surface ocean via particle flux) to temperature.
The model accounts for the observed variability in export efficiency due to temperature without idealizing out the remaining variability that evinces particle flux's complexity. This model is then used to estimate the metabolically-driven change in average export efficiency over the era of long-term global sea surface temperature records, and it is shown that the underlying mechanism may help explain glacial-interglacial atmospheric carbon dioxide drawdown. The relationship between particle flux and net primary production is then explored. Given that these are inextricable but highly variable and measured on different effective scales, it is hypothesized that a quantitative relationship emerges between collections of the two measurements - i.e. that they can be related not measurement-by-measurement but rather via their probability distributions.
It is shown that on large spatial or temporal scales both are consistent with lognormal distributions, as expected if each is considered as the collective result of many subprocesses. A relationship is then derived between the log-moments of their distributions and agreement is found between independent estimates of this relationship, suggesting that upper ocean particle flux is predictable from net primary production on large spatiotemporal scales. Finally, the attenuation of particle flux with depth is explored. It is shown that while several particle flux-versus-depth models capture observations equivalently, these carry very different implications mechanistically and for magnitudes of export out of the surface ocean. A model is then proposed for this relationship that accounts for measurements of both the flux profile and of the settling velocity distribution of particulate matter, and is thus more consistent with and constrained by empirical knowledge.
Possible future applications of these models are discussed, as well as how they could be tested and/or constrained observationally.
by Brendan Barry.
Ph. D.
Ph.D. Joint Program in Physical Oceanography (Massachusetts Institute of Technology, Department of Earth, Atmospheric, and Planetary Sciences; and the Woods Hole Oceanographic Institution)

APA, Harvard, Vancouver, ISO, and other styles

17

Sandelius, Hugo. "Creating Knowledge Graphs using Distributional Semantic Models." Thesis, KTH, Skolan för datavetenskap och kommunikation (CSC), 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-199702.

Full text

Abstract:

This report researches a method for creating knowledge graphs, a specific way of structuring information, using distributional semantic models. Two different algorithms for selecting graph edges and two different algorithms for labelling edges are tried, and variations of those are evaluated. We perform experiments comparing our knowledge graphs with existing manually constructed knowledge graphs of high quality, with respect to graph structure and edge labels. We find that the algorithms usually produces graphs with a structure similar to that of manually constructed knowledge graphs, as long as the data set is sufficiently large and general, and that the similarity of edge labels to manually chosen edge labels vary widely depending on input.

APA, Harvard, Vancouver, ISO, and other styles

18

Siminski, Peter Economics Australian School of Business UNSW. "Essays on the distributional impacts of government." Publisher:University of New South Wales. Economics, 2008. http://handle.unsw.edu.au/1959.4/41238.

Full text

Abstract:

This thesis consists of three independent essays, unified by the common theme of the distributional impacts of government. The first paper estimates the price elasticity of demand for pharmaceuticals amongst high-income older people in Australia. It exploits a natural experiment by which some people gained entitlement to a price reduction through the Commonwealth Seniors Health Card (CSHC). The preferred model is a nonlinear Instrumental Variable (IV) difference-in-difference regression, estimated on repeated cross sectional survey data using the Generalised Method of Moments. No significant evidence is found for endogenous card take-up, and so cross-sectional estimates are also considered. Taking all of the results and possible sources of bias into account, the ??headline?? estimate is -0.1, implying that quantity demanded is not highly responsive to price. The elasticity estimate is a key input into the second paper which analyses the distributional impact of the CSHC. I consider the trade-off between moral hazard and risk pooling. There have been few previous attempts internationally to address this trade-off empirically for any health insurance scheme. The utility gain through risk-pooling is found to be negligible. However, the deadweight loss through moral hazard may be considerable. I also use an illustrative model to demonstrate the possible effects of the CSHC on inter-temporal savings behaviour. While the CSHC may induce some people to save, it may have the opposite effect on others. The net impact was not determined. The third paper estimates the Australian public sector wage premium. It includes a detailed critical review of the methods available to address this issue. The chosen approach is a quasi-differenced panel data model, estimated by nonlinear IV, which has many advantages over other methods and has not been used before for this topic. I find a positive average public sector wage premium for both sexes. The best estimates are 10.0% for men and 7.1% for women. The estimate for men is statistically significant (p < 0.04) and borders on significance for women (p < 0.07). No evidence is found to suggest that the public sector has an equalising effect on the wages of its workers.

APA, Harvard, Vancouver, ISO, and other styles

19

Trenn, Stephan [Verfasser]. "Distributional differential algebraic equations / von Stephan Trenn." Ilmenau : Univ.-Verl, 2009. http://d-nb.info/998021652/34.

Full text

APA, Harvard, Vancouver, ISO, and other styles

20

Mansoor, Rashid. "Assessing Distributional Properties of High-Dimensional Data." Doctoral thesis, Internationella Handelshögskolan, Högskolan i Jönköping, IHH, Economics, Finance and Statistics, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:hj:diva-22547.

Full text

Abstract:

This doctoral thesis consists of five papers in the field of multivariate statistical analysis of high-dimensional data. Because of the wide application and methodological scope, the individual papers in the thesis necessarily target a number of different statistical issues. In the first paper, Monte Carlo simulations are used to investigate a number of tests of multivariate non-normality with respect to their increasing dimension asymptotic (IDA) properties as the dimension p grows proportionally with the number of observations n such that p/n → c where is a constant. In the second paper a new test for non-normality that utilizes principal components is proposed for cases when p/n → c. The power and size of the test are examined through Monte Carlo simulations where different combinations of p and n are used. The third paper treats the problem of the relation between the second central moment of a distribution to its first raw moment. In order to make inference of the systematic relationship between mean and standard deviation, a model that captures this relationship by a slope parameter (β) is proposed and three different estimators of this parameter are developed and their consistency proven in the context where the number of variables increases proportionally to the number of observations. In the fourth paper, a Bayesian regression approach has been taken to model the relationship between the mean and standard deviation of the excess return and to test hypotheses regarding the β parameter. An empirical example involving Stockholm exchange market data is included. Then finally in the fifth paper three new methods to test for panel cointegration

APA, Harvard, Vancouver, ISO, and other styles

21

Haro, Lopez Ruben Alejandro. "Data adaptive Bayesian analysis using distributional mixtures." Thesis, Imperial College London, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.299509.

Full text

APA, Harvard, Vancouver, ISO, and other styles

22

Weeds, Julie Elizabeth. "Measures and applications of lexical distributional similarity." Thesis, University of Sussex, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.398753.

Full text

APA, Harvard, Vancouver, ISO, and other styles

23

McGregor, Stephen. "Geometric methods for context sensitive distributional semantics." Thesis, Queen Mary, University of London, 2018. http://qmro.qmul.ac.uk/xmlui/handle/123456789/36691.

Full text

Abstract:

This thesis describes a novel methodology, grounded in the distributional semantic paradigm, for building context sensitive models of word meaning, affording an empirical exploration of the relationship between words and concepts. Anchored in theoretical linguistic insight regarding the contextually specified nature of lexical semantics, the work presented here explores a range of techniques for the selection of subspaces of word co-occurrence dimensions based on a statistical analysis of input terms as observed within large-scale textual corpora. The relationships between word-vectors that emerge in the projected subspaces can be analysed in terms of a mapping between their geometric features and their semantic properties. The power of this modelling technique is its ability to generate ad hoc semantic relationships in response to an extemporaneous linguistic or conceptual situation. The product of this approach is a generalisable computational linguistic methodology, capable of taking input in various forms, including word groupings and sentential context, and dynamically generating output from a broad base model of word co-occurrence data. To demonstrate the versatility of the method, this thesis will present competitive empirical results on a range of established natural language tasks including word similarity and relatedness rating, metaphor and metonymy detection, and analogy completion. A range of techniques will be applied in order to explore the ways in which different aspects of projected geometries can be mapped to different semantic relationships, allowing for the discovery of a range of lexical and conceptual properties for any given input and providing a basis for an empirical exploration of distinctions between the semantic phenomena under analysis. The case made here is that the flexibility of these models and their ability to extend output to evaluations of unattested linguistic relationships constitutes the groundwork for a method for the extrapolation of dynamic conceptual relationships from large-scale textual corpora. This method is presented as a complement and a counterpoint to established distributional methods for generating lexically productive word-vectors. Where contemporary vector space models of distributional semantics have almost universally involved either the factorisation of co-occurrence matrices or the incremental learning of abstract representations using neural networks, the approach described in this thesis preserves the connection between the individual dimensions of word-vectors and statistics pertaining to observations in a textual corpus. The hypothesis tested here is that the maintenance of actual, interpretable information about underlying linguistic data allows for the contextual selection of non-normalised subspaces with more nuanced geometric features. In addition to presenting competitive results for various computational linguistic targets, the thesis will suggest that the transparency of its representations indicates scope for the application of this model to various real-world problems where an interpretable relationship between data and output is highly desirable. This, finally, demonstrates a way towards the productive application of the theory and philosophy of language to computational linguistic practice.

APA, Harvard, Vancouver, ISO, and other styles

24

Cordeiro, Silvio Ricardo. "Distributional models of multiword expression compositionality prediction." Thesis, Aix-Marseille, 2017. http://www.theses.fr/2017AIXM0501/document.

Full text

Abstract:

Les systèmes de traitement automatique des langues reposent souvent sur l'idée que le langage est compositionnel, c'est-à-dire que le sens d'une entité linguistique peut être déduite à partir du sens de ses parties. Cette supposition ne s’avère pas vraie dans le cas des expressions polylexicales (EPLs). Par exemple, une "poule mouillée" n'est ni une poule, ni nécessairement mouillée. Les techniques pour déduire le sens des mots en fonction de leur distribution dans le texte ont obtenu de bons résultats sur plusieurs tâches, en particulier depuis l'apparition des word embeddings. Cependant, la représentation des EPLs reste toujours un problème non résolu. En particulier, on ne sait pas comment prédire avec précision, à partir des corpus, si une EPL donnée doit être traitée comme une unité indivisible (p.ex. "carton plein") ou comme une combinaison du sens de ses parties (p.ex. "eau potable"). Cette thèse propose un cadre méthodologique pour la prédiction de compositionnalité d'EPLs fondé sur des représentations de la sémantique distributionnelle, que nous instancions à partir d’une variété de paramètres. Nous présenterons une évaluation complète de l'impact de ces paramètres sur trois nouveaux ensembles de données modélisant la compositionnalité d'EPLs, en anglais, français et portugais. Finalement, nous présenterons une évaluation extrinsèque des niveaux de compositionnalité prédits par le modèle dans le contexte d’un système d'identification d'EPLs. Les résultats suggèrent que le choix spécifique de modèle distributionnel et de paramètres de corpus peut produire des prédictions de compositionnalité qui sont comparables à celles présentées dans l'état de l'art
Natural language processing systems often rely on the idea that language is compositional, that is, the meaning of a linguistic entity can be inferred from the meaning of its parts. This expectation fails in the case of multiword expressions (MWEs). For example, a person who is a "sitting duck" is neither a duck nor necessarily sitting. Modern computational techniques for inferring word meaning based on the distribution of words in the text have been quite successful at multiple tasks, especially since the rise of word embedding approaches. However, the representation of MWEs still remains an open problem in the field. In particular, it is unclear how one could predict from corpora whether a given MWE should be treated as an indivisible unit (e.g. "nut case") or as some combination of the meaning of its parts (e.g. "engine room"). This thesis proposes a framework of MWE compositionality prediction based on representations of distributional semantics, which we instantiate under a variety of parameters. We present a thorough evaluation of the impact of these parameters on three new datasets of MWE compositionality, encompassing English, French and Portuguese MWEs. Finally, we present an extrinsic evaluation of the predicted levels of MWE compositionality on the task of MWE identification. Our results suggest that the proper choice of distributional model and corpus parameters can produce compositionality predictions that are comparable to the state of the art

APA, Harvard, Vancouver, ISO, and other styles

25

Cordeiro, Silvio Ricardo. "Distributional models of multiword expression compositionality prediction." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2018. http://hdl.handle.net/10183/174519.

Full text

Abstract:

Sistemas de processamento de linguagem natural baseiam-se com frequência na hipótese de que a linguagem humana é composicional, ou seja, que o significado de uma entidade linguística pode ser inferido a partir do significado de suas partes. Essa expectativa falha no caso de expressões multipalavras (EMPs). Por exemplo, uma pessoa caracterizada como pão-duro não é literalmente um pão, e também não tem uma consistência molecular mais dura que a de outras pessoas. Técnicas computacionais modernas para inferir o significado das palavras com base na sua distribuição no texto vêm obtendo um considerável sucesso em múltiplas tarefas, especialmente após o surgimento de abordagens de word embeddings. No entanto, a representação de EMPs continua a ser um problema em aberto na área. Em particular, não existe um método consolidado que prediga, com base em corpora, se uma determinada EMP deveria ser tratada como unidade indivisível (por exemplo olho gordo) ou como alguma combinação do significado de suas partes (por exemplo tartaruga marinha). Esta tese propõe um modelo de predição de composicionalidade de EMPs com base em representações de semântica distribucional, que são instanciadas no contexto de uma variedade de parâmetros. Também é apresentada uma avaliação minuciosa do impacto desses parâmetros em três novos conjuntos de dados que modelam a composicionalidade de EMP, abrangendo EMPs em inglês, francês e português. Por fim, é apresentada uma avaliação extrínseca dos níveis previstos de composicionalidade de EMPs, através da tarefa de identificação de EMPs. Os resultados obtidos sugerem que a escolha adequada do modelo distribucional e de parâmetros de corpus pode produzir predições de composicionalidade que são comparáveis às observadas no estado da arte.
Natural language processing systems often rely on the idea that language is compositional, that is, the meaning of a linguistic entity can be inferred from the meaning of its parts. This expectation fails in the case of multiword expressions (MWEs). For example, a person who is a sitting duck is neither a duck nor necessarily sitting. Modern computational techniques for inferring word meaning based on the distribution of words in the text have been quite successful at multiple tasks, especially since the rise of word embedding approaches. However, the representation of MWEs still remains an open problem in the field. In particular, it is unclear how one could predict from corpora whether a given MWE should be treated as an indivisible unit (e.g. nut case) or as some combination of the meaning of its parts (e.g. engine room). This thesis proposes a framework of MWE compositionality prediction based on representations of distributional semantics, which we instantiate under a variety of parameters. We present a thorough evaluation of the impact of these parameters on three new datasets of MWE compositionality, encompassing English, French and Portuguese MWEs. Finally, we present an extrinsic evaluation of the predicted levels of MWE compositionality on the task of MWE identification. Our results suggest that the proper choice of distributional model and corpus parameters can produce compositionality predictions that are comparable to the state of the art.

APA, Harvard, Vancouver, ISO, and other styles

26

Wu, Menghua M. Eng Massachusetts Institute of Technology. "Few-shot text classification with distributional signatures." Thesis, Massachusetts Institute of Technology, 2020. https://hdl.handle.net/1721.1/130200.

Full text

Abstract:

Thesis: M. Eng., Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science, May, 2020
Date of graduation confirmed by MIT Registrar Office. "May 2020." Cataloged from student-submitted PDF of thesis.
Includes bibliographical references (pages 18-21).
We explore meta-learning for few-shot text classification. Meta-learning has shown strong performance in computer vision, where low-level patterns are transferable across learning tasks. However, directly applying this approach to text is challenging-lexical features highly informative for one task may be insignificant for another. Thus, rather than learning solely from words, our model also leverages their distributional signatures, which encode pertinent word occurrence patterns. Our model is trained within a meta-learning framework to map these signatures into attention scores, which are then used to weight the lexical representations of words. We demonstrate that our model consistently outperforms prototypical networks learned on lexical knowledge (Snell et al., 2017) in both few-shot text classification and relation classification by a significant margin across six benchmark datasets (20.0% on average in 1-shot classification).
by Menghua Wu.
M. Eng.
M.Eng. Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science

APA, Harvard, Vancouver, ISO, and other styles

27

Jacobsen, Mark R. "Efficiency and distributional impacts of environmental regulation /." May be available electronically:, 2007. http://proquest.umi.com/login?COPT=REJTPTU1MTUmSU5UPTAmVkVSPTI=&clientId=12498.

Full text

APA, Harvard, Vancouver, ISO, and other styles

28

Zhao, Yilu. "Distributional criteria for verbal valency in Chinese /." Leuven : Peeters, 1996. http://catalogue.bnf.fr/ark:/12148/cb38955510z.

Full text

APA, Harvard, Vancouver, ISO, and other styles

29

Wang, Mingliang. "Distributional modelling in forestry and remote sensing." Thesis, University of Greenwich, 2005. http://gala.gre.ac.uk/6337/.

Full text

Abstract:

The use of distributional models in forestry is investigated, in terms of their capability of modelling distributions of forest mensurational attributes, for modelling and inventory purposes. Emphasis is put on: (i) the univariate and bivariate modelling of tree diameters and heights for stand-level modelling work, and (ii) heuristic methods for use and analysis of distributions which occur in multi-temporal EO imagery, (for the inventory-related tasks of land-use mapping, change detection and growth modelling). In univariate distribution modelling, a new parameterization of the widely-used Johnson’s SB distribution is given, and new Logit-Logistic, generalised Weibull and the Burr system (XII, III, IV) models are introduced into forest modelling. The Logit-Logistic distribution is found to be the best among those compared. The use of regression-based methods of parameter estimation is also investigated. In the domain of bivariate distribution modelling of tree diameters and heights the Plackett method (a particular form of copula) is used to construct Plackett-based bivariate Beta, SB and Logit-Logistic distributions, (the latter two are new), which are compared with each other and the SBB distribution. Other copula functions, including the normal copula, are further employed (for the first time in forest modelling) to construct bivariate distributional models. With the normal copula, the superiority of the Logit-Logistic in the univariate domain is extended into the bivariate domain. To use multi-temporal EO imagery, two pre-processing procedures are necessary: image to image co-registration, and radiometric correction. A spectral correlation-based pixel-matching method is developed to “refine” manually selected control points to achieve very accurate image co-registration. A robust non-parametric method of spectral-distribution standardization is used for relative radiometric correction between images. Finally, possibilities for further research are discussed.

APA, Harvard, Vancouver, ISO, and other styles

30

Rayner, Glen. "Statistical methodologies for quantile-based distributional families." Thesis, Queensland University of Technology, 1999.

Find full text

APA, Harvard, Vancouver, ISO, and other styles

31

Tornés, Bes Elisabet. "Distributional patterns of diatom communities in Mediterranean rivers." Doctoral thesis, Universitat de Girona, 2009. http://hdl.handle.net/10803/7875.

Full text

Abstract:

Aquesta tesi tracta la jerarquia i l'heterogeneïtat dels sistemes fluvials que afecten l'estructura de les comunitats bentòniques de diatomees. A nivell regional, es van buscar diferents grups de punts i les seves espècies indicadores, es va estudiar la resposta de les comunitats de diatomees als gradients ambientals, es va avaluar la utilitat de diferents índexs de diatomees i es va buscar el millor sistema de classificació per a condicions de referència. A nivell de conca, es volien definir els factors que determinen la distribució longitudinal de la diversitat de les comunitats de diatomees. Finalment, a nivell d'hàbitat es van determinar quins factors afecten les algues i els cianobacteris a aquesta escala i es va examinar la contribució relativa de l'ambient i l'espai en la distribució de la biomassa i composició d'algues i cianobacteris. Per tant, els diferents capítols d'aquesta tesi han estat desenvolupats seguint aquest esquema.
This thesis deals with the hierarchy and heterogeneity of stream systems affecting the structure of benthic diatom communities. At a regional level, I search for different groups of sites and their indicator taxa, I studied the responses of the diatom communities to the gradients of environmental variables, I tested the usefulness of diatom indices and I searched for the best classification system for reference conditions. At a watershed level my interest was to define the factors that determined the longitudinal distribution of diversity of diatom communities. Finally, at a habitat level it was interesting to determine the factors affecting algae and cyanobacteria at this scale and examine the relative effects of environmental factors and space on the distribution of biomass and composition of benthic algae and cyanobacteria. Thus, the different chapters of the thesis had been approached following this scheme.

APA, Harvard, Vancouver, ISO, and other styles

32

Lingard, Justin Jonathan Nicholas. "Size distributional analysis of urban airborne particulate matter." Thesis, University of Leeds, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.414252.

Full text

APA, Harvard, Vancouver, ISO, and other styles

33

Gaarder, Marie Moland. "The distributional effects of illness and air pollution." Thesis, University College London (University of London), 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.271115.

Full text

APA, Harvard, Vancouver, ISO, and other styles

34

Bakar, Rosni. "The distributional effects of higher education in Malaysia." Thesis, University of Exeter, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.245943.

Full text

APA, Harvard, Vancouver, ISO, and other styles

35

Schiavone, S. E. "Distributional theories for multidimensional fractional integrals and derivatives." Thesis, University of Strathclyde, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.382492.

Full text

APA, Harvard, Vancouver, ISO, and other styles

36

Dacuycuy, Lawrence Barcena. "Empirical essays on wage functional and distributional analyses." Kyoto University, 2006. http://hdl.handle.net/2433/136042.

Full text

APA, Harvard, Vancouver, ISO, and other styles

37

Glass, Thomas Westbrook. "Essays on the distributional aspects of Social Security /." Digital version accessible at:, 1999. http://wwwlib.umi.com/cr/utexas/main.

Full text

APA, Harvard, Vancouver, ISO, and other styles

38

Ley, Christophe. "Univariate and multivariate symmetry: statistical inference and distributional aspects." Doctoral thesis, Universite Libre de Bruxelles, 2010. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/210029.

Full text

Abstract:

This thesis deals with several statistical and probabilistic aspects of symmetry and asymmetry, both in a univariate and multivariate context, and is divided into three distinct parts.

The first part, composed of Chapters 1, 2 and 3 of the thesis, solves two conjectures associated with multivariate skew-symmetric distributions. Since the introduction in 1985 by Adelchi Azzalini of the most famous representative of that class of distributions, namely the skew-normal distribution, it is well-known that, in the vicinity of symmetry, the Fisher information matrix is singular and the profile log-likelihood function for skewness admits a stationary point whatever the sample under consideration. Since that moment, researchers have tried to determine the subclasses of skew-symmetric distributions who suffer from each of those problems, which has led to the aforementioned two conjectures. This thesis completely solves these two problems.

The second part of the thesis, namely Chapters 4 and 5, aims at applying and constructing extremely general skewing mechanisms. As such, in Chapter 4, we make use of the univariate mechanism of Ferreira and Steel (2006) to build optimal (in the Le Cam sense) tests for univariate symmetry which are very flexible. Actually, their mechanism allowing to turn a given symmetric distribution into any asymmetric distribution, the alternatives to the null hypothesis of symmetry can take any possible shape. These univariate mechanisms, besides that surjectivity property, enjoy numerous good properties, but cannot be extended to higher dimensions in a satisfactory way. For this reason, we propose in Chapter 5 different general mechanisms, sharing all the nice properties of their competitors in Ferreira and Steel (2006), but which moreover can be extended to any dimension. We formally prove that the surjectivity property holds in dimensions k>1 and we study the principal characteristics of these new multivariate mechanisms.

Finally, the third part of this thesis, composed of Chapter 6, proposes a test for multivariate central symmetry by having recourse to the concepts of statistical depth and runs. This test extends the celebrated univariate runs test of McWilliams (1990) to higher dimensions. We analyze its asymptotic behavior (especially in dimension k=2) under the null hypothesis and its invariance and robustness properties. We conclude by an overview of possible modifications of these new tests./

Cette thèse traite de différents aspects statistiques et probabilistes de symétrie et asymétrie univariées et multivariées, et est subdivisée en trois parties distinctes.

La première partie, qui comprend les chapitres 1, 2 et 3 de la thèse, est destinée à la résolution de deux conjectures associées aux lois skew-symétriques multivariées. Depuis l'introduction en 1985 par Adelchi Azzalini du plus célèbre représentant de cette classe de lois, à savoir la loi skew-normale, il est bien connu qu'en un voisinage de la situation symétrique la matrice d'information de Fisher est singulière et la fonction de vraisemblance profile pour le paramètre d'asymétrie admet un point stationnaire quel que soit l'échantillon considéré. Dès lors, des chercheurs ont essayé de déterminer les sous-classes de lois skew-symétriques qui souffrent de chacune de ces problématiques, ce qui a mené aux deux conjectures précitées. Cette thèse résoud complètement ces deux problèmes.

La deuxième partie, constituée des chapitres 4 et 5, poursuit le but d'appliquer et de proposer des méchanismes d'asymétrisation très généraux. Ainsi, au chapitre 4, nous utilisons le méchanisme univarié de Ferreira and Steel (2006) pour construire des tests de symétrie univariée optimaux (au sens de Le Cam) qui sont très flexibles. En effet, leur méchanisme permettant de transformer une loi symétrique donnée en n'importe quelle loi asymétrique, les contre-hypothèses à la symétrie peuvent prendre toute forme imaginable. Ces méchanismes univariés, outre cette propriété de surjectivité, possèdent de nombreux autres attraits, mais ne permettent pas une extension satisfaisante aux dimensions supérieures. Pour cette raison, nous proposons au chapitre 5 des méchanismes généraux alternatifs, qui partagent toutes les propriétés de leurs compétiteurs de Ferreira and Steel (2006), mais qui en plus sont généralisables à n'importe quelle dimension. Nous démontrons formellement que la surjectivité tient en dimension k > 1 et étudions les caractéristiques principales de ces nouveaux méchanismes multivariés.

Finalement, la troisième partie de cette thèse, composée du chapitre 6, propose un test de symétrie centrale multivariée en ayant recours aux concepts de profondeur statistique et de runs. Ce test étend le célèbre test de runs univarié de McWilliams (1990) aux dimensions supérieures. Nous en analysons le comportement asymptotique (surtout en dimension k = 2) sous l'hypothèse nulle et les propriétés d'invariance et de robustesse. Nous concluons par un aperçu sur des modifications possibles de ces nouveaux tests.
Doctorat en Sciences
info:eu-repo/semantics/nonPublished

APA, Harvard, Vancouver, ISO, and other styles

39

Hirvela, Kyle Ray. "Park Access and Distributional Inequities in Pinellas County, Florida." Scholar Commons, 2011. http://scholarcommons.usf.edu/etd/3150.

Full text

Abstract:

Although environmental justice research has traditionally focused on environmental disamenities and health hazards, recent studies have begun to examine social inequities in the distribution of urban amenities such as street trees and parks that provide several direct and indirect health benefits to local residents. This thesis adds to this knowledge by evaluating distributional inequities in both distribution and access to parks in Pinellas County, the most densely populated and one of the most racially segregated counties in Florida. An important objective was to determine if neighborhoods with lower levels of park access are more likely to contain a significantly higher proportion of racial/ethnic minorities and low-income residents. The analysis uses precise locations of parks, street network data, and block group level census socio-demographic information. Parks are classified into three categories based on park size (acres). For the first research question, park service areas are constructed to determine the socio-demographic composition of residents closest to each park based on a 400-meter walking distance along the road network. Park service areas allow the calculation of potential park congestion, in acres per person, and the analysis of statistical associations between socio-demographic characteristics and park acreage. The results indicate less congested parks and higher acreage for racial/ethnic minority residents and those below poverty level, with respect to White residents and those above the poverty level. The second research question examines inequities in the geography of park access as measured through the creation of network-based buffer zones based on walking distances from each park. Statistical analysis, including basic comparisons and a multivariate least squares regression, indicate significantly lower accessibility to parks for residents who are Hispanic and 65 or more years in age. Parks are significantly more accessible to neighborhoods containing a higher proportion of individuals in poverty, vacant houses, and those within the cities of Clearwater or St. Petersburg. This research contributes to a growing body of literature on park inequity by using walking distances on local streets to define park service areas and focusing on an urban area (Pinellas County, Florida) that has not been examined in past studies of environmental justice.

APA, Harvard, Vancouver, ISO, and other styles

40

Bristow, Abigail Lesley. "The distributional impact of subsidies in urban public transport." Thesis, University of Newcastle Upon Tyne, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.315602.

Full text

APA, Harvard, Vancouver, ISO, and other styles

41

Firici, Maria Carmen. "Distributional impacts of common agricultural policy adoption by Romania." Thesis, University of Aberdeen, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.401443.

Full text

Abstract:

The Common Agricultural Policy (CAP) of the European Union (EU) leads to higher prices for agricultural products than under free market conditions. Therefore, the agricultural sector of a large country such as Romania plays a major role in EU accession negotiations. In particular, the implementation of the CAP has different impacts on different socio-economic groups. This study estimates, for the first time for Romania, the distributional impacts of the implementation of the CAP on different groups of agricultural producers and food consumers. Part of the research focuses on the assessment and analysis of the economic welfare (real income) effects of policy-induced price changes on seven groups of agricultural producers, using the traditional Marshallian approach of changes in producer surplus, and assuming an immediate accession of Romania to the EU. The application of CAP price support implies an estimated annual producer welfare gain of about Euro 800 million, or 2.4 per cent of Romanian GDP in 1999. Disaggregating the results by farm type, the large commercial state farming companies receive most of this benefit. Addition of direct payments to farmers at 25 per cent of the EU-15 rate increases the aggregate producer welfare gain to about 4 per cent of Romanian GDP, and substantially increases benefits to small independent household farms. Consumer welfare effects are analysed using a 10-fold breakdown of Romanian households and the Slutsky Compensating Variation approach. Estimates suggest that, if the current CAP results in an average increase of 10 per cent in all Romanian food prices, the lowest-income groups (i.e. urban and rural unemployed households, and urban pensioner households) will be the most affected, with their cost of living rising by up to 6.7 per cent. The estimation of gains or losses for each type of farm, and of income adjustments for each type of Romanian household, as a result of CAP adoption may assist Romanian policy makers in their debate over the agricultural and social strategies during the pre-accession period.

APA, Harvard, Vancouver, ISO, and other styles

42

Thwaites, Peter. "Lexical and distributional influences on word association response generation." Thesis, Cardiff University, 2018. http://orca.cf.ac.uk/119182/.

Full text

Abstract:

This thesis is the result of an attempt to investigate the determinants of word association responses. The aim of this work was to identify those properties of words - their frequency, grammatical class, and textual distribution, for example - which influence the generation of word association responses, and to align these effects with wider sycholinguistic views of the mental lexicon. The experimental work in the early chapters focuses on grammatical influences on wordassociation. In particular, it is demonstrated that both grammatical class and verb transitivity influence the type of response most likely to be selected by participants. The immediately following chapters ask why this would be so. The analysis of several models of word association suggests that the development of a clearer understanding of the way in which a word's textual distribution impacts upon associative response patterns may be an important stepping stone towards a coherent model of associative response generation. In the later part of the thesis, a series of novel experiments is conducted comparing word association response patterns with corpus-derived data. This work in turn lays the foundation for the development of a new usage-based model of word association, which is shown, in the penultimate chapter, to be capable of explaining a wide range of research findings, including not only the grammatical class and transitivity-related findings described above, but also earlier findings relating to the influence of lexical variables on the structure of the associative network, and to the discovery of individual and age-related response patterns in word association.

APA, Harvard, Vancouver, ISO, and other styles

43

Partlett, Christopher. "Asymmetry and other distributional properties in medical research data." Thesis, University of Birmingham, 2015. http://etheses.bham.ac.uk//id/eprint/6348/.

Full text

Abstract:

The central theme of this thesis is to investigate the use of non-parametric methods for making inferences about a random sample with an unknown distribution function. The overarching aim is the development of new methods to make inferences regarding the nature of the unknown distribution to enhance medical research. Initially,the focus is exclusively on the asymmetry of a random variable. In particular, a recently proposed measure of asymmetry provides the foundation for the proposal and development of a new test for symmetry. The potential applications of the test and measure are applied to a number of medical research settings including randomised trials. Moreover, guidance is provided on its implementation, with particular emphasis on the problem of small sample estimation. This investigation is then generalised to examine asymmetry across multiple studies. In particular, meta-analysis methods are used to synthesise information about the amount of asymmetry in several studies. Further, a detailed simulation study is carried out to investigate the impact of asymmetry on linear models and meta-analyses of randomised trials, in terms of the accuracy of the treatment effect estimate and the coverage of confidence and prediction intervals. Finally, the scope of the investigation is widened to encompass the problem of comparing and synthesising information about the probability density function and cumulative distribution function, based on samples from multiple studies. The meta-analysis of the smooth distribution function estimate is then applied to propose new methods for conducting meta-analyses of diagnostic test accuracy, which have a number of merits compared to the existing methodology.

APA, Harvard, Vancouver, ISO, and other styles

44

Henderson, Eric Kord. "A text representation language for contextual and distributional processing." Thesis, University of Cambridge, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.608403.

Full text

APA, Harvard, Vancouver, ISO, and other styles

45

Ataguba, John E. "Distributional impact of health care finance in South Africa." Doctoral thesis, University of Cape Town, 2012. http://hdl.handle.net/11427/10030.

Full text

Abstract:

Includes bibliographical references.
In South Africa, health care is financed through different mechanisms - allocations from general taxes, private health insurance contributions and direct out-of-pocket payments. These mechanisms impact differently on different households. While there are empirical evidence in developed countries, the distributional impact of such payments and methodological challenges in such assessments in the context of Africa are scarce. Borrowing from the tax literature, the thesis aims to assess the relative impact of health care financing on households' welfare and standards of living. Methodological issues around the assessment of income redistributive impact of health care payments in the context of South Africa are also explored.

APA, Harvard, Vancouver, ISO, and other styles

46

Kasturiratna, Dhanuja. "Assessing the Distributional Assumptions in One-Way Regression Model." Bowling Green State University / OhioLINK, 2006. http://rave.ohiolink.edu/etdc/view?acc_num=bgsu1148479945.

Full text

APA, Harvard, Vancouver, ISO, and other styles

47

Cory, Dennis C., and Lester D. Taylor. "On the Distributional Implications of Safe Drinking Water Standards." CAMBRIDGE UNIV PRESS, 2017. http://hdl.handle.net/10150/623433.

Full text

Abstract:

The provision of safe drinking water provides a dramatic example of the inherent complexity involved in incorporating environmental justice (EJ) considerations into the implementation and enforcement of new environmental standards. To promote substantive EJ, implementation policy must be concerned with the net risk reduction of new and revised regulations. The regulatory concern is that higher water bills for low-income customers of small public water systems may result in less disposable income for other health-related goods and services. In the net, this trade-off may be welfare decreasing, not increasing. Advocates of Health–Health Analysis have argued that the reduction in health-related spending creates a problem for traditional benefit-cost analysis since the long-run health implications of this reduction are not considered. The results of this investigation tend to support this contention. An evaluation of the internal structure of consumption expenditures reveals that low-expenditure households can be expected to react to an increase in the relative price of housing-related goods and services due to a water-rate hike by reducing both housing and health-related expenditures. That is, the representative low-expenditure household re-establishes equilibrium by not only decreasing housing-related spending, but also by decreasing spending on health-related expenditures in a modest but significant way. These results reflect the fact that expenditures on housing are a major proportion of overall household spending, and that accommodating drinking water surcharges exacerbates both health and food security concerns for low-expenditures households.

APA, Harvard, Vancouver, ISO, and other styles

48

Bångman, Gunnel. "Equity in cost benefit analysis by using distributional weights." Saarbrücken VDM Verlag Dr. Müller, 2006. http://d-nb.info/991198069/04.

Full text

APA, Harvard, Vancouver, ISO, and other styles

49

Frey, Elizabeth G. "An examination of distributional assumptions in LANDSAT TM imagery /." Online version of thesis, 1995. http://hdl.handle.net/1850/12253.

Full text

APA, Harvard, Vancouver, ISO, and other styles

50

Chung, Hess T. "Three essays on fiscal policy and its distributional consequences." [Bloomington, Ind.] : Indiana University, 2009. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:3344569.

Full text

Abstract:

Thesis (Ph.D.)--Indiana University, Dept. of Economics, 2009.
Title from PDF t.p. (viewed on Oct. 5, 2009). Source: Dissertation Abstracts International, Volume: 70-02, Section: A, page: 0627. Adviser: Eric M. Leeper.

APA, Harvard, Vancouver, ISO, and other styles

Dissertations / Theses on the topic 'Distributional'

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles