Since the transportation sector is highly responsible for U.S. fuel consumption and emissions, assessing the environmental impacts of transportation activities is essential for air-quality improvement programs. Also, high emitting vehicles need to be considered in the modeling of mobile-source emissions, because they contribute to a large portion of the total emissions, although they comprise a small portion of the vehicle fleet. In the context of this research, the thesis quantifies the environmental impacts of roadway grades and proposes a procedure that can enhance the screening of high emitting vehicles. First, the study quantifies the environmental impacts of roadway grades. Although roadway grades are known to affect vehicle fuel consumption and emission rates, there do not appear to be any systematic evaluations of these impacts in the literature. Consequently, this study addresses this void by offering a systematic analysis of the impact of roadway grades on vehicle fuel consumption and emission rates using the INTEGRATION microscopic traffic simulation software. The energy and emission impacts are quantified for various cruising speeds, under stop and go conditions, and for various traffic signal control scenarios. The study demonstrates that the impact of roadway grade is significant with increases in fuel consumption and emission rates in excess of 9% for a 1% increase in roadway grade. Consequently, a reduction in roadway grades in the range of 1% can offer savings that are equivalent to various forms of advanced traffic management systems. Second, the study proposes a new procedure for estimating vehicle mass emissions from remote sensing device measurements that can be used to enhance HEV screening procedures. Remote Sensing Devices (RSDs) are used as supplementary tools for screening high emitting vehicles (HEVs) in the U.S. in order to achieve the National Ambient Air Quality Standards (NAAQS). However, tailpipe emissions in grams cannot be directly measured using RSDs because they use a concentration-based technique. Therefore, converting a concentration measurement to mass emissions is needed. The research combines the carbon balance equation with fuel consumption estimates to make the conversion. In estimating vehicle fuel consumption rates, the VT-Micro model and a Vehicle Specific Power (VSP)-based model (the PERE model) are considered and compared. The results of the comparison demonstrate that the VSP-based model under-estimates fuel consumption at 79% and produces significant errors (R2 = 45%), while the VT-Micro model produces a minimum systematic error of 1% and a high degree of correlation (R2 = 87%) in estimating a sample vehicle's (1993 Honda Accord with a 2.4L engine) fuel consumption. The sample vehicle was correctly identified 100%, 97%, and 89% as a normal vehicle in terms of HC, CO, NOX emissions, respectively, using its in-laboratory measured emissions. Its estimated emissions yielded 100%, 97%, and 88% of correct detection rates in terms of HC, CO, NOX emissions, respectively. The study clearly demonstrates that the proposed procedure works well in converting concentration measurements to mass emissions and can be applicable in the screening of HEVs and normal emitting vehicles for several vehicle types such as sedans, station wagons, full-size vans, mini vans, pickup trucks, and SUVs. / Master of Science

This bachelor thesis investigates inequalities present within the elementary schools of Helsingborg during the period from 2013 to 2023. Through statistical analysis, it explores various dimensions of difference among students, considering factors such as gender, school affiliation, academic performance, and whether or not one recently arrived in the country. The study relies on data sourced from the Helsingborg municipality and addresses two main questions: the extent and nature of inequalities in Helsingborg’s schools and how these inequalities have evolved over the specified period. Two definitions of inequality are utilised: “Differences between groups” (e.g., between boys and girls) and “Differences within the same group” (indicated by high standard deviation within a group). These differences are quantified using three metrics: the sum of students’ grades (merit value), the number of classes passed, and whether or not the student qualified for further education (gymnasium). The methodology includes nonparametric hypothesis tests and regression analysis. The tests employed are Kruskal-Wallis’ test, Dunn’s test, χ2 test for independence, and Fisher’s exact test, with appropriate corrections. Standard linear regression is also applied. The findings highlight disparities in academic achievement and access to higher education. Notable results include a significant dichotomy between newly arrived students and other students across all performance metrics. There were no significant changes in inequality over the time period.

No description available.

Pallet cant quality directly impacts pallet part processing and material costs. By knowing the quality of the cants being processed, pallet manufacturers can predict costs to attain better value from their raw materials and more accurately price their pallets. The study objectives were 1) to develop a procedure for accurately predicting hardwood pallet part yield as a function of raw material geometry and grade, processing equipment, and pallet part geometry, 2) to develop a model for accurately predicting raw material costs for hardwood pallet parts as a function of yield, 3) to examine current pallet industry methods of determining hardwood cant quality, and 4) to develop and evaluate hardwood cant grading rules for use in the pallet industry. Yield studies were necessary to accurately quantify the relationship between yield and cant quality. Thirty-one yield studies were conducted throughout the Eastern United States at pallet mills producing pallet parts from hardwood cants. 47, 258 board feet of hardwood cants were graded, and the usable pallet part yield and yield losses were determined for each grade. Yield losses were separated into three components: kerf loss, dimension loss, and defect loss. Kerf and dimension losses are a function of raw material and part geometry and were calculated without regard to cant quality. Defect loss is dependent on cant quality and was calculated for each cant grade as a function of total yield, kerf loss, and dimension loss. Mathematical models were developed from twenty-eight mill studies to predict each yield loss component as a function of cant dimensions, grade, and orientation, cutting bill parameters, pallet part dimensions, and kerf. Dimension and kerf losses were predicted geometrically. Regression analysis was used to predict defect loss. Results indicated that these models accurately predicted the total yield of usable pallet parts and pallet part material costs as a function of cant quality and price. Results also indicated that the pallet industry's current method of counting the number of "bad" ends per cant bundle to determine cant quality is not adequate. The effectiveness of the proposed cant grading rules was determined by grading cants and analyzing the cant grade distributions and corresponding pallet part yields. The grade rules produced statistically different quality divisions between grades. However, a more practical single cant grade based on the minimum quality for the proposed grade 2 rules is recommended. / Master of Science

Syftet med denna studie är att bidra med ny kunskap om svenska gymnasieelevers betygsfördelning och betygsutveckling i ämnet Dansteknik. Studien omfattar en totalundersökning av avgångsbetygen för de 414 gymnasieelever som avslutat sina studier vid det estetiska programmets dansinriktning i Stockholms stad under åren 2014 - 2018. Elevernas betygsfördelningar i olika kurser i ämnet Dansteknik samt deras betygsutveckling över kurserna har analyserats statistiskt. Studien visar att eleverna har höga betyg i ämnet Dansteknik, dels i relation till elevernas betyg i övriga ämnen men även i relation till riksnivåerna för andra ämnen, kurser och elevers avgångsbetyg generellt. Studien visar också att elever i hög grad behåller en liknande betygsnivå i Dansteknik under hela utbildningen samt att elevers och gymnasieskolors val av kurser i ämnet Dansteknik påverkar elevernas betygsutveckling och med stor sannolikhet även deras kunskapsutveckling i ämnet. / The purpose of this study is to contribute with new knowledge about grade distribution and students’ subsequent grades in the subject Dance technique as part of Swedish upper secondary education. The study encompasses the upper secondary school grades of the 414 students that ended the Arts Programme in dance in the City of Stockholm, Sweden, during the years 2014 - 2018. The results are based on a statistical analysis of these students’ course grades in the subject Dance technique. The study shows that students have generally received high grades in the subject Dance technique, both in relation to their grades in other subjects as well as in relation to national grade averages in various courses and subjects. The study also shows that the students maintain a somewhat even grade level throughout their education and that students’ grade level and learning in Dance technique is affected by students’ and schools’ course choices in the subject.

Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico / Grades de Bragg nÃo-lineares tÃm sido consideradas desde o final do sÃculo passado para aplicaÃÃes em sistemas de comunicaÃÃes Ãpticas e sensoriamento. O estudo de pulsos ultra-curtos em grades de Bragg lineares, entretanto, sà tem sido considerado nos Ãltimos anos, devido ao desenvolvimento de tÃcnicas numÃricas especÃficas para se resolver o problema. Neste trabalho, foi realizado um estudo analÃtico-numÃrico das caracterÃsticas de transmissÃo e reflexÃo das grades de Bragg nÃo-lineares. Pela primeira vez, foram consideradas variaÃÃes periÃdicas da nÃo-linearidade no dispositivo operando no regime de onda continua, levando a uma nova classe de grades nÃo-uniformes. CaracterÃsticas dos estados bi- e multi-estÃveis foram extensamente investigados nas grades de Bragg nÃo-lineares. TambÃm, pela primeira vez, foi realizado o estudo numÃrico de pulsos ultracurtos ($sim$1 ps) incidindo em grades nÃo-lineares. O enfoque foi dado para a dependÃncia da intensidade de um pulso ultracurto ao passar por tal grade. Foram estudadas, ainda, as dependÃncias na forma temporal da profundidade de modulaÃÃo da grade e do Ãndice nÃo-linear. Grades apodizadas foram consideradas, jà que estas sÃo de importÃncia fundamental nos sitemas de comunicaÃÃes modernos. / Nonlinear fiber Bragg gratings has been considered since the end of last century for applications in optical communications and sensor techniques. The investigation of ultrashort pulses in linear Bragg gratings, however has been considered in the last few years due the development of specifical numerical techniques to solve this problem. In the present work an analytical and numerical study of the reflection and transmission characteristics of nonlinear Bragg gratings was done. For the first time, it has been considered periodic variations of the nonlinearity in that devices operating in the continuous wave regime, leading to a new class of nonuniform gratings. It was extensively investigated the bi- and multistable characteristics in these nonlinear fiber Bragg gratings. Also, for the first time, the numerical study of ultrahsort pulses ($sim$1 ps) incident in nonlinear gratings was done. The focus was the input pulse intensity dependence on that gratings. Also, the depedences in the time shapes of grating index modulation depth and nonlinear index were studied. Apodized gratings were considered since they are of fundamental importance in modern communications systems.

[pt] O objetivo deste trabalho é desenvolver uma solução completa para o traçado de raios de cenas dinâmicas utilizando a GPU. Para que este algoritmo atinja desempenho interativo, é necessário utilizar uma estrutura espacial para reduzir os testes de interseção entre raios e triângulos da cena. Observa-se que, quando há movimento na cena, é necessário atualizar esta estrutura de aceleração, seja alterando-a parcialmente ou reconstruindo-a inteiramente. Adotamos a segunda estratégia por ser capaz de tratar o caso geral de movimento não-estruturado. Como a construção da estrutura deve ser feita da forma mais eficiente possível, escolhemos utilizar uma Grade Uniforme como foco de nossa pesquisa. Suas vantagens incluem um algoritmo de construção simples e um percurso de raios eficiente. Para explorar o poder de processamento em paralelo de uma GPU, é necessário manter os dados da cena e da estrutura de aceleração dentro da placa gráfica, evitando transferências custosas de memória entre a GPU e a CPU. Propomos neste trabalho uma técnica para construir uma grade uniforme inteiramente na GPU. Usando nosso método, é possível reconstruir toda a estrutura em poucos milissegundos, enquanto mantém-se a alta qualidade da grade obtida. Além disso, propomos uma implementaçoes do algoritmo de traçado de raios de forma a aproveitar o processamento em paralelo da GPU. Nosso procedimento é implementado inteiramente dentro da placa gráfica, onde há acesso direto para os dados dos triângulos da cena, bem como as informações da grade uniforme construída. Utilizando a solução proposta, somos capazes de obter taxas de visualização interativas mesmo para cenas com movimentos não-estruturados, incluindo texturas, sombras e até mesmo reflexões. / [en] We present a technique for ray tracing dynamic scenes using the GPU. In order to achieve interactive rendering rates, it is necessary to use a spatial structure to reduce the number of ray-triangle intersections performed. Whenever there is movement in the scene, this structure is entirely rebuilt. This way, it is possible to handle general unstructured motion. For this purpose, we have developed an algorithm for reconstructing Uniform Grids entirely inside the graphics hardware. In addition, we present ray-traversal and shading algorithms fully implemented on the GPU, including textures, shadows and reections. Combining these techniques, we demonstrate interactive ray tracing performance for dynamic scenes, even with unstructured motion and advanced shading effects.

No description available.

With the implementation of No Child Left Behind legislation and a push for reform curricula, prospective teachers must be prepared to facilitate learning at a conceptual level. To address these concerns, an exploratory mixed methods investigation of twenty-eight prospective middle grades teachers’ mathematics knowledge for teaching geometry and mathematical connection-making was conducted at a large public southeastern university. Participants completed a diagnostic assessment in mathematics with a focus on geometry and measurement (CRMSTD, 2007), a mathematical connections evaluation, and a card sort activity. Mixed methods data analysis revealed prospective middle grades teachers’ mathematics knowledge for teaching geometry was underdeveloped and the mathematical connections made by prospective middle grades teachers were more procedural than conceptual in nature.

ABSTRACT As industries are upgrading rapidly from a lower steel grade to higher ones it has become necessary to study the effect of changing from lower steel grades to higher grades. This thesis reports on fatigue life and behaviour, economic implications and material composition of these higher strength steels (HSS) as compared to the conventional grades. Three grades are commercially available in South Africa: 300W, 350W and 460W. These different steel grades (conventional and HSS) with the same moment capacities where subjected to constant dynamic stresses and the fatigue crack growth of the overloading and unloading were monitored and compared with each other. The influences of the overloading and unloading made standard grades perform better under repeated loading than the HSS, since HSS have been proved to have poor ductility, resulting in lower number of cycles to failure. An 85% increase in material cost was generated as HSS replaces the conventional lower steel grades. Reduction in number of cycles to failure in HSS was over 500%. A space analysis for a multi-storey building with 10 beam floors was conducted for the various steel grades using a software package. The buckling and linear behaviours of these structures were compared. Although the deflections were not too far apart, it was shown clearly that grade lower steel grades performed better than the higher grades. An optimization was conducted using the parameters discussed in the text or obtained from experiment and computer modelling, in order to aid in the selection criterion of general purpose steel. Grade 300W was the optimal grade although the result was based mainly on the cost and fatigue behaviour of the three grades.