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Magister Scientiae - MSc / Our main results are that splay trees are faster for sorted insertion, where AVL trees are faster for random insertion. For searching, skip lists are faster than single class top-down splay trees, but two-class and multi-class top-down splay trees can behave better than skip lists. / South Africa

The Academic Vocabulary List (AVL) was produced by a rationale for word inclusion improved from the methodology used to generate Coxhead's AWL (Gardner & Davies, 2014). It offers a comprehensive view of high frequency academic vocabulary that could greatly benefit ELLs if implemented into ELL curricula (Gardner & Davies, 2014). However, because of the newness of the list, there are few learning resources currently utilizing the AVL. The major objective of this thesis project was to create digital flashcards for the first 500 words of the AVL to increase the list's accessibility to ELLs and teachers worldwide. These flashcards were made available through Quizlet's online interface. This paper describes the two types of flashcards developed: AVL words paired with simplified English (learner) definitions, and AVL words paired with L1 translations into seven languages. It further describes an evaluation of these flashcards by ESOL teachers working at a U.S. intensive English program, and concludes with suggestions for the future development of AVL learning resources.

For decades, teachers and language learners have been concerned about matching the difficulty level of texts to the proficiency level of learners in order to achieve comprehensible input, which leads to effective learning. Some leveling systems and research use word lists as part of their leveling processes, particularly the Academic Word List. The Academic Vocabulary List (AVL) has not been explored yet as a leveling tool, so this study aims to address this lack of research by examining how the AVL words vary in cumulative frequency bands and also in separate frequency bands with regard to level and topic. The AVL was divided into 5 frequency bands and compared against corpora of biology and U.S. history texts at the elementary, junior high, high school, and university levels. Results showed that the biology texts had a higher percentage of total AVL tokens than the history texts did, suggesting that the AVL may be more suitable for some disciplines than others. For the cumulative bands, Bands 1 through 3 proved to have the highest percent deltas, suggesting that words 1 to 800 are the most useful to learn. Looking at each separate band, Bands 1 and 2 had the highest percent of AVL tokens at the high school level, implying that the words of these bands are especially valuable for learners at this level. The university level had the highest percentage for Bands 3 through 5. There was no statistical significance for any band concerning the factor of the relationship between topic and level, but there was statistical significance for the factor of proficiency level at every level. For the factor of topic, there was significance for every band except Band 3. For each band, the elementary and junior high texts were generally similar to each other concerning the AVL tokens found in them. High school and university texts were similar to each other for Bands 1 and 2 but were not similar to each other for Bands 3 through 5.

The primary objective of this study is to develop an integrated public transportation planning framework to evaluate and plan Advanced Public Transportation Systems (APTS). With this purpose, a systems approach point of view is adopted to study the influence of new APTS technology in supply and demand transit variables. In this project the Systems Dynamics methodology is adopted to track the dynamic behavior of model variables and feedback loops forming among them. The proposed framework is illustrated in a case study involving automated vehicle location systems (AVL) applied to a small transit community. The proposed approach follows the same steps of the Systems Dynamics method; First, identify some key variables which are not only susceptive to AVL technology but also affect the supply-demand relationship of a bus transit environment. Second, trace and simplify the causal relationships of the variables considering impacts of facility supply changes to passenger demand responses and vice versa. To accomplish this, four detailed sub-models representing parts of the transit system are developed and combined under the Systems Dynamics methodology point of view. Theses Sub-models are: 1) demography, 2) urban transportation planning, 3) bus operations, and 4) evaluation. Finally, to validate the model procedure, the model is applied to a case study. This study attempts to encompass as many as possible factors around a bus transit system environment which can be impacted by new APTS technology to illustrate the use of the proposed framework. Some of these factors include: 1) Demographic characteristics; 2) urban or social activity of the study area and 3) changes to transportation facilities. The case study illustrates how the physical characteristics of the transit systems such as traffic demand, traffic conditions along the transit route, route layout, and bus performance can be affected by the new technology. Since APTS impacts are time dependent a continuous multi-loop simulation technique is adopted to track dynamic changes of all model variables. The analysis of the transit system is carried over a 20-year life cycle to illustrate the long term dynamics of the feedback structures inherent in the model. <i>[Vita removed Aug. 2, 2010. GMc]</i> / Ph. D.

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Automatic vehicle locator (AVL) systems, utilizing military's global positioning system, may impact response time to law enforcement calls for service. In order to evaluate the impacts of AVL on response time to calls for service at the Altamonte Springs Police Department (ASPD), computer aided dispatch (CAD) data from years 1999 to 2003 were analyzed. The analysis of each of the data sets consisted of an initial sequence chart, an analysis of variance (ANOVA), a means plot and a linear regression. Interviews of ASPD personnel were conducted to understand user perceptions of AVL. Based on the ANOVA results, trends indicate that weekly response time was significantly lower during the AVL partial implementation period than during the pre or post AVL stages across all categories of data analyzed. Based on the regression results, trends indicate that the overall impact of AVL on response time for all categories analyzed is flat and show AVL as having no overall impact on response time across all calls for service analyzed. An exception to this is the findings related to Priority 3 calls for service; however this exception can be attributed to performance during the pre AVL implementation stage. These results do not suggest a capability for AVL to reduce response time to calls for service in a meaningful comprehensive way. Thus, the study's hypotheses are not supported.

A Região Metropolitana de São Paulo (RMSP) sofre de sérios problemas de congestionamento, assim como muitas outras cidades de grande porte. Uma possível solução, proposta por pesquisadores de transportes, economia e ciências ambientais, é a implantação de um sistema de congestion charging, chamada no Brasil de pedágio urbano. Um dos objetivos do presente trabalho foi estabelecer os conceitos relacionados a este assunto e ilustrar as principais questões relacionadas à sua implantação. Espera-se que este trabalho possa auxiliar o desenvolvimento de estudos de avaliação da viabilidade e de impactos de sistemas propostos de congestion charging. Para atingir este objetivo, toca-se em diversos assuntos, como a definição de congestionamento e as formas de medi-lo, a base conceitual e teórica dos sistemas de congestion charging e seus diversos esquemas de diferenciação. São expostas também as medidas de mitigação de congestionamento que já foram implantadas na RMSP, quais foram os estudos já desenvolvidos considerando este tipo de política para a RMSP, e casos em que sistemas de congestion charging já foi implantado. Neste trabalho, desenvolveu-se também um modelo de escolha discreta a partir dos dados da Pesquisa Origem e Destino 2007 do METRÔ, onde pessoas deveriam escolher entre \"Transporte Coletivo\" e \"Transporte Público\". Este modelo foi utilizado para avaliar o potencial de impacto na divisão modal e de arrecadação de um congestion charge aplicado ao centro expandido de São Paulo. Adverte-se, porém, que os resultados obtidos são meramente ilustrativos. Mostra-se, também, que é possível avaliar a capacidade ociosa do sistema de transporte coletivo a partir dos dados disponíveis de bilhetagem e de GPS dos ônibus. Este processo é exemplificado através do cálculo de capacidade de uma única viagem de um único ônibus, dada a dificuldade de automatização deste processo para abranger toda a frota. / The São Paulo Metropolitan Region (SPMR) suffers from severe traffic congestion, as do many other large-scale urban areas around the world. A possible solution to this issue, which has been suggested by transportation, economics and environmental researchers, is the implementation of a congestion charging system. One of the objectives of this project is to establish clear concepts and shed light on the main issues regarding these systems by means of a comprehensive literary review. It is expected that this project may help the development of in-depth studies carried in order to evaluate the viability and impacts of congestion charging proposals. In order to achieve this goal, many subjects are addressed, such as the definition of congestion, how its measured, the theoretical backgrounds that support congestion charging schemes, their different degrees of differentiation, which policies were enacted in order to reduce traffic congestion in São Paulo, what considerations and studies have already been developed for Brazil and São Paulo regarding these systems and where have these systems been successfully installed. Later chapters deal with another goal of this project: estimating how a congestion charging system would affect SPMR. This was achieved through a multinomial logit model, where decision-makers choose between \"Public Transportation\" and \"Private Automobile\". The results presented at this phase are merely indicative of certain tendencies and should not be considered final. This project also attempts to show that given the available Automated Fare Collection (AFC) data and Automated Vehicle Location (AVL) data, it is possible to estimate the current public transportation system\'s unused capacity. The author shows this by calculating the capacity of one bus trip using these data, but also explains the difficulties of expanding this analysis to the whole of SPMR\'s public transportation system.