Although the collisions of electrons and atomic hydrogen has been studied for several decades, there is still neither a complete database of scattering data, nor a universal method that would let generate such data. For astronomical and other purposes the cross sections of electron-hydrogen collisions are necessary, in a broad range of energies - from tenths of electronvolt to millions of electronvolts. In this work the author concentrates on several established approaches to electron-atom scattering and confronts results of his own implementations of these methods against the published data and results of freely available computer codes. A special attention is given to the overlaps of different methods, so that in the end a database with easy user interface can be offered for common practical usage of scattering data in applied fields.

Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico / As aplicaÃÃes da mecÃnica estatÃstica no estudo do comportamento humano coletivo nÃo sÃo uma novidade. No entanto, nas Ãltimas dÃcadas vimos um aumento enorme do interesse no estudo da sociedade usando a fÃsica. Nesta tese, utilizando tÃcnicas da fÃsica, nÃs estudamos leis de escala nÃo-lineares em sistemas sociais. Na primeira parte da tese realizamos a anÃlise de dados e modelagem de eleiÃÃes pÃblicas. Mostramos que o nÃmero de votos de um candidato escala nÃo-linearmente com o dinheiro gasto na campanha. Para nossa surpresa, a correlaÃÃo revelou uma relaÃÃo de escala sublinear, o que significa que o "preÃo" mÃdio de um voto cresce à medida que o nÃmero de votos aumenta. Usando um modelo de campo mÃdio descobrimos que a nÃo-linearidade emerge da concorrÃncia e a distribuiÃÃo de votos à causalmente determinada pela distribuiÃÃo do dinheiro gasto na campanha. AlÃm disso, mostramos que o modelo à capaz de prever razoavelmente o nÃmero final de votos vÃlidos atravÃs de um argumento heurÃstico simples. Por fim, apresentamos o nosso trabalho sobre alometria de indicadores sociais. NÃs mostramos como homicÃdios, mortes em acidentes de carro e suicÃdios crescem com a populaÃÃo das cidades brasileiras. Diferentemente de homicÃdios (superlinear) e eventos fatais em acidentes de carro (isomÃtrico), encontramos um comportamento sublinear entre o nÃmero de suicÃdios e a populaÃÃo de cidades, o que revela uma possÃvel evidÃncia de influÃncia social na ocorrÃncia de suicÃdios. / The applications of statistical mechanics in the study of collective human behavior is not a novelty. However, in the past few decades we shaw a huge spike of interest on the study of society using physics. In this thesis we explore nonlinear scaling laws in social systems using physical techniques. First we perform data analysis and modeling applied to elections. We show that the number of votes of a candidate scales nonlinear with the money spent at the campaign. To our surprise, the correlation revealed a sublinear scaling, which means that the average âpriceâ of one vote grows as you increase the number of votes. Using a mean-field model we find that the sublinearity emerges from the competition and the distribution of votes is causally determined by the distribution of money campaign. Moreover, we show that the model is able to reasonably predict the final number of valid votes through a simple heuristic argument. Lastly, we present our work on allometric scaling of social indicators. We show how homicides, deaths in car crashes, and suicides scales with the population of Brazilian cities. Differently from homicides (superlinear) and fatal events in car crashes (isometric), we find sublinear scaling behavior between the number of suicides and city population, which reveal a possible evidence for social influence on suicides occurrences.

Introduzimos uma familia de trajetorias aleatorias coalescentes com certo tipo de comportamento radial a qual chamaremos de Teia Poissoniana radial discreta. Mostramos que o limite fraco na escala difusiva desta familia e uma familia de trajetorias aleatorias coalescentes que chamaremos de Teia Browniana radial. Por m, caraterizamos o objeto limite como um mapeamento continuo da Teia Browniana restrita num subconjunto de R2. / We introduce a family of coalescing random paths with certain kind of radial behavior. We call them the discrete radial Poisson Web. We show that under diusive scaling this family converges in distribution to a family of coalescing random paths which we call radial Brownian Web. Finally, we characterize the limiting object as a continuous mapping of the Brownian Web restricted to a subset of R2.

Nós apresentamos o processo K numa árvore, que é um processo de Markov com estados instantâneos e generaliza o processo K no grafo completo, como o limite do modelo de armadilha numa árvore, e aplicamos esse resultado para derivar um limite de escala para o modelo de armadilha do GREM. / We present the K process on a tree, which is a Markov process with instantaneous states and generalises the K process on the complete graph, as a limit of the trap model on a tree, and apply this result to derive a scaling limit to the GREM-like trap model.

Este estudo buscou compreender a associação entre obesidade e variantes da eficácia da adaptação em homens adultos entre 30 e 50 anos. Utilizou como instrumentos a Escala Diagnóstica Adaptativa Operacionalizada Revisada (EDAO-R), a Entrevista Preventiva, a Escala de Avaliação Global do Funcionamento (AGF) e a Escala Toronto de Alexitimia (ETA-20). Contou com a colaboração de quatro sujeitos do sexo masculino, com idades entre 30 e 42 anos. Três sujeitos participaram desse estudo por meio da empresa em que trabalham e um foi contatado por intermédio de um profissional de saúde. Os resultados obtidos mostram que a obesidade está associada, predominantemente, a aspectos afetivos. Entre os setores adaptativos prepondera, então, como o mais importante, o setor Afetivo-Relacional. Todos apresentaram esse setor como pouquíssimo adequado. A pouquíssima adequação encontrada nesse setor repercute, nesses sujeitos, no setor Orgânico. O setor Produtivo também recebe interferências e apresenta prejuízos em dois dos participantes do estudo. Deste modo, concluímos que os fatores emocionais corroboram com a instalação e manutenção da obesidade. / This study aimed to understand the association between obesity and effectiveness variants of adaptation in male adults between 30 and 50 years old. It used as instruments the Operational Adaptive Diagnostic Scale Revised (OADS-R), the Preventive Interview, the Global Assessment Scale of Functioning (GAF), and the Toronto Scale of Alexithymia (TSA-20). It had the cooperation of four male subjects, aged between 30 and 42. Three subjects took part in this study through the company where they worked, and one was contacted by a health professional. The results show that obesity is mainly associated with affective aspects. Among adaptive sectors, therefore, the Affective-Relational sector preponderates as the most important one. They all presented this sector as considerably inappropriate. This very little appropriation reverberates, in these subjects, in the Organic sector. The Productive sector also receives interferences and presents damages in two participants of the study. Consequently, we came to the conclusion that emotional factors corroborate with obesity presentation and maintenance.

Esta tese avalia os benefícios e desafios associados com a operação em uma ampla faixa de frequências e tensões próximas ao limiar do transistor. A diminuição da tensão de alimentação em circuitos digitais CMOS apresenta grandes vantagens em termos de potência consumida pelo circuito. Esta diminuição da potência é acompanhada por uma redução da performance, reflexo da diminuição na tensão de alimentação. A operação de circuitos digitais no ponto de energia mínima é comumente associada ao regime de operação abaixo do limiar do transistor, trazendo enormes penalidades em performance e variabilidade. Esta dissertação mostra que é possível obter 8X mais eficiência energética com uma ampla faixa dinâmica de tensão e frequência, da tensão nominal até o limite inferior da operação próximo ao limiar do transistor. Como parte deste estudo, uma biblioteca de células digitais CMOS para esta ampla faixa de frequências foi desenvolvida. A biblioteca de células lógicas foi exercitada em um PDK comercial de 65nm para operação próximo ao limiar do transistor, reduzindo os efeitos da variabilidade sem comprometer o projeto em termos de área e energia quando operando em inversão forte. Para operar próximo e abaixo do limiar do transistor as células devem ser desenvolvidas com um número limitado de transistores em série. Nosso estudo mostra que uma performance aceitável em termos de margens de ruído estático é obtida para um conjunto restrito de células, onde são empregados no máximo dois transistores em série. Reportamos resultados para projetos de média complexidade que incluem um filtro notch de 25kgates, um microcontrolador 8051 de 20kgates, e 4 circuitos combinacionais/ sequenciais do conjunto de avaliação ISCAS. Neste trabalho, é estudada a máxima frequência atingida em cada tensão de alimentação, desde 0.15V até 1.2V. O ponto de mínima energia é demonstrado em operação abaixo do limiar do transistor, aproximadamente 0.29V, oque representa um ganho de 2X em eficiência energética comparado ao regime de operação próximo ao limiar do transistor. Embora o pico de eficiência energética ocorra abaixo do limiar do transistor para os circuitos estudados, nós também demonstramos que nesta tensão de alimentação ultra-baixa o atraso e a potência sofrem um impacto substancial devido ao aumento na variabilidade, atigindo uma degradação em performance de 30X, com respeito à operação próxima ao limiar do transistor. / This thesis assesses the benefits and drawbacks associated with a very wide range of frequency when operation at near-threshold is considered. Scaling down the supply voltage in digital CMOS circuits presents great benefits in terms of power reduction. Such scaling comes with a performance penalty, hence in digital synchronous circuits the reduction in frequency of operation follows, for a given circuit layout, the VDD reduction. Minimum-energy operation of digital CMOS circuits is commonly associated to the sub-VT regime, carrying huge performance and variability penalties. This thesis shows that it is possible to achieve 8X higher energy-efficiency with a very-wide range of dynamic voltage-frequency scaling, from nominal voltages down to the lower boundary of near-VT operation. As part of this study, a CMOS digital cell-library for such wide range of frequencies was developed. The cell-library is exercised in a 65nm commercial PDK and targets near-VT operation, mitigating the variability effects without compromising the design in terms of area and energy at strong inversion. For near-VT or sub-VT operation the cells have to be designed with few stacked transistors. Our study shows that acceptable performance in terms of static-noise margins is obtained for a constrained set of cells, for which a maximum of 2-stacked transistors are allowed. In this set we include master-slave registers. We report results for medium complexity designs which include a 25kgates notch filter, a 20kgates 8051 compatible core, and 4-combinational/4-sequential ISCAS benchmark circuits. In this work the maximum frequency attainable at each supply for a wide variation of voltage is studied from 150mV up to nominal voltage (1.2V). The sub-VT operation is shown to hold the minimum energy-point at roughly 0.29V, which represents a 2X energy-saving compared to the near-VT regime. Although energy-efficiency peaks in sub-VT for the circuits studied, we also show that in this ultra-low VDD the circuit timing and power suffer from substantially increased variability impact and a 30X performance drawback, with respect to near-VT.

Although cricket is played around the world by all ages, very little attention has been focused on junior cricket. The research presented here evaluated the effects on junior cricket of reducing the pitch length, developed a method for scaling the pitch to suit the players and applied this method to the under-11 age group. In the first of four studies it was established that shortening the cricket pitch had positive effects for bowlers, batters and fielders at both club and county standards, consequently resulting in matches that were more engaging. The second study found that top under-10 and under-11 seam bowlers released the ball on average 3.4° further below horizontal on a 16 yard pitch compared with a 19 yard pitch. This was closer to elite adult pace bowlers release angles and should enable junior players to achieve greater success and develop more variety in their bowling. The third study calculated where a good length delivery should be pitched to under-10 and under-11 batters in order to provoke uncertainty, and also examined the influence of pitch length on batters decisions to play front or back foot shots according to the length of the delivery. A shorter pitch should strengthen the coupling between the perception of delivery length and appropriate shot selection, and the increased task demand should lead to improved anticipation; both are key features of skilled batting. In the final study a method of calculating the optimal pitch length for an age group was developed which used age-specific bowling and batting inputs. This was applied to scale the pitch for under-11s giving a pitch length of 16.22 yards (14.83 m), 19% shorter than previously recommended for the age group by the England and Wales Cricket Board. Scaled in this way across the junior age groups, pitch lengths would fit the players better as they develop, enabling more consistent ball release by bowlers and temporal demands for batters, as well as greater involvement for fielders.

Developmental score scales represent the performance of students along a continuum, where as students learn more they move higher along that continuum. Unidimensional item response theory (UIRT) vertical scaling has become a commonly used method to create developmental score scales. Research has shown that UIRT vertical scaling methods can be inconsistent in estimating grade-to-grade growth, within-grade variability, and separation of grade distributions (effect size) of developmental score scale. In particular the finding of scale shrinkage (decreasing within-grade score variability as grade-level increases) has led to concerns about and criticism of IRT vertical scales. The causes of scale shrinkage have yet to be fully understood. Real test data and simulation studies have been unable to provide complete answers as to why IRT vertical scaling inconsistencies occur. Violations of assumptions have been a commonly cited potential cause for the inconsistent results. For this reason, this dissertation is an extensive investigation into how violations of the three assumptions of UIRT vertical scaling - local item dependence, unidimensionality, and similar reliability of grade level tests - affect estimated developmental score scales. Simulated tests were developed that purposefully violated a UIRT vertical scaling assumption. Three sets of simulated tests were created to test the effect of violating a single assumption. First, simulated tests were created with increasing, decreasing, low, medium, and high local item dependence. Second, multidimensional simulated tests were created by varying the correlation between dimensions. Third, simulated tests with dissimilar reliability were created by varying item parameters characteristics of the grade level tests. Multiple versions of twelve simulated tests were used to investigate UIRT vertical scaling assumption violations. The simulated tests were calibrated under the UIRT model to purposefully violate an assumption of UIRT vertical scaling. Each simulated test version was replicated for 1000 random examinee samples to assess the bias and standard error of estimated grade-to-grade-growth, within-grade-variability, and separation-of-grade-distributions (effect size) of the estimated developmental score scales. The results suggest that when UIRT vertical scaling assumptions are violated the resulting estimated developmental score scales contain standard error and bias. For this study, the magnitude of standard error was similar across all simulated tests regardless of the assumption violation. However, bias fluctuated as a result of different types and magnitudes of UIRT vertical scaling assumption violations. More local item dependence resulted in more grade-to-grade-growth and separation-of-grade-distributions bias. And local item dependence resulted in developmental score scales that displayed scale expansion. Multidimensionality resulted in more grade-to-grade-growth and separation-of-grade-distributions bias when the correlation between dimensions was smaller. Multidimensionality resulted in developmental score scales that displayed scale expansion. Dissimilar reliability of grade level tests resulted in more grade-to-grade-growth bias and minimal separation-of-grade-distributions bias. Dissimilar reliability of grade level tests resulted in scale expansion or scale shrinkage depending on the item characteristics of the test. Limitations of this study and future research are discussed.

In an attempt to address the dearth of research examining the development and effects of intersectional, multiple marginalized identities, the scale developed in this study quantified the cultural variation in gender role expression of Asian American women. The following describes the development of the Multicultural Gender Role Scale for Asian American women (MGRS-AAW). The scale was conceptualized and largely constructed based on existing research: with specific attention regarding the qualitative themes and findings of Corpus and Miville (2013). A total of 71 items were administered to a sample of 327 participants who identified as Asian/Asian American women. Results were subjected to an Exploratory Factor Analysis and a total of 26 items were retained. Four independent constructs emerged, which closely mirrored and delineated the findings of the qualitative study: 1) Bicultural conflict, 2) Passivity, 3) Asian Values, and 4) Awareness. Further psychometric evaluation of the scale resulted in convergent validity of the subscales with other measures, such as the Attitudes Toward Women Scale (AWS) and the Asian American Racism Related Inventory (AARRSI), and discriminant validity was proven in regard to the lack of correlation among subscales with collected Grade Point Average. Findings were discussed in relation to strengths and weaknesses of the study, implications for the field, and future areas of studies.

Previous research has shown a link between the spatial words children use and their performance on spatial reasoning tasks. There is a dearth of measures of spatial language, especially those that focus on a specific type of word. This dissertation introduces three studies, using two measures of dimensional adjective comprehension, one in English and one in Spanish. Study one found that bilingual children’s knowledge of dimensional adjectives in one language is not predictive of their performance on dimensional adjectives in the other language, but that general vocabulary within a language predicts performance in that language. This study also showed that within a pair of polar opposite terms (e.g., long and short) children are more likely to know the term describing the big dimension and not the small dimension than vice versa. The second study found that the number of dimensional concepts children comprehend predicts how well they perform on a spatial scaling test, controlling for age and general vocabulary. The final study failed to find a link between dimensional adjective knowledge and performance on the children’s mental transformation task. These findings might have important implications for early education, showing that supporting children’s understanding of language might have an impact on their spatial reasoning.