Manufacturers of cast metal parts are interested in the development of a feedback control system for use with the Precision Sand-Casting (PSC) process. As industry demands the ability to cast more complex geometries, there are a variety of challenges that engineers have to address. Certain characteristics of the mold, such as thick-to-thin transitions, extensive horizontal or flat surfaces, and sharp corners increase the likelihood of generating defective casts due to the turbulent metal-flow during fills. Consequently, it is critical that turbulent flow behavior within the mold be minimized as much as possible. One way to enhance the quality of the fill process is to adjust the flow rate of the molten metal as it fills these critical regions of the mold. Existing systems attempt to predict the position of the metal level based on elapsed time from the beginning of the fill stage. Unfortunately, variability in several aspects of the fill process makes it very difficult to consistently predict the position of the metal front. A better approach would be to embed a sensor that can detect the melt through a lift-off distance and determine the position of the metal-front. The information from this sensor can then be used to adjust the flow rate of the aluminum as the mold is filled. This thesis presents the design of a novel non-invasive sensor monitoring system. When deployed on the factory floor, the sensing system will provide all necessary information to allow process engineers to adjust the metal flow-rate within the mold and thereby reduce the amount of scrap being produced. Moreover, the system will exhibit additional value in the research and development of future mold designs.

A agricultura de precisão é um conjunto de tecnologias que prevê o manejo espacializado dos fatores de produção, baseado em informações coletadas e georeferenciadas. O mapa de produtividade é uma informação importante, pois materializa a resposta da cultura a todos os fatores. Diversos monitores de produtividade comerciais estão disponíveis no mercado para a coleta de informações de produtividade de forma bastante adensada. Devido à automação e à alta quantidade de informações, diversos erros ocorrem no processo de coleta e a retirada destes erros é um fator de qualidade da informação. A proposta do trabalho é desenvolver uma rotina de filtragem de dados brutos que elimine erros presentes em mapas de produtividade. Como primeira etapa do desenvolvimento do processo de filtragem, foi realizada a análise e caracterização dos erros presentes em seis mapas de produtividade provenientes de seis diferentes monitores de produtividade comerciais. Erros de posicionamento foram encontrados, representados por pontos fora do talhão, sendo que pequenos erros de posicionamento não podem ser detectados pela metodologia desenvolvida. Foram encontrados pontos com produtividade nula, umidade de grãos nula ou ausente e pontos com posição repetida. Pontos coletados com largura de plataforma de corte diferente da total foram considerados erros de medição de área, pois carregam a influência do operador na definição da largura da plataforma de corte efetivamente utilizada. Para a caracterização do erro de intervalo de enchimento foi desenvolvida uma metodologia para identificar o sentido de deslocamento da colhedora, possibilitando assim, a medição do espaço necessário para que o monitor esteja sensível às variações naturais da produtividade. A distância percorrida durante o intervalo de enchimento variou de 0 a 44m. Foram estabelecidos limites estatísticos para discrepância de valores de produtividade, sendo que foram encontrados pontos com valores de produtividade fora dos limites estabelecidos. Com base nas características de cada tipo de erro, foi desenvolvida uma rotina de filtragem de dados brutos. A rotina consistiu de 7 etapas, sendo que cada uma age sobre determinado tipo de erro de acordo com suas características. Na primeira etapa são retirados do conjunto pontos com erro grosseiro de posicionamento, representados por pontos fora dos limites do talhão. As etapas de número 2 a 5 consistem na retirada de pontos com produtividade nula ou ausente, pontos com largura de plataforma de corte diferente da total, pontos com umidade nula ou ausente e com distância nula entre pontos. A sexta, age sobre pontos gravados durante o intervalo de enchimento, tendo por base a distância referente ao erro e o número de pontos gravados durante tal distância. Foi desenvolvido um algoritmo de busca, identificação e eliminação dos pontos gravados durante o intervalo de enchimento. A sétima etapa estabelece limites estatísticos para discrepância de valores de produtividade e elimina pontos fora destes limites. De maneira geral, a filtragem de dados melhorou a modelagem da dependência espacial e elevou a qualidade final dos mapas de produtividade. / Precision farming is a set of technologies that provide the capacity to manage the yield based on spacialized information. Yield map is an important information as it describes the answer of the crop to the inputs and soil conditions. There are several yield monitors in the market to collect yield information automatically. Due to the automation of the collection, some errors may be collected together with good data, and the elimination of those errors from the data set represents information quality. This work proposes the development a filtering routine of raw data to eliminate errors. The first step is the analysis and characterization of the errors present on data from six different commercial yield monitors. The errors found are positioning errors, represented by points outside the field. Small positioning errors cannot be detected by this methodology. It was found points with null or no yield, null or no grain moisture and points with the same position. Points with swath width different from the total swath width were considered as area measuring errors because they take account the interpretation of the operator about the actual swath width. For the characterization of the combine filling time it was developed a methodology to identify the running direction of the machine, allowing the estimation of the distance required to fill the threshing mechanism of the combine. The distance during the filling time was found to be between 0 and 44m. Yield outlier limits were established, and values over and under the limits were found in the data. Based on the characteristics of each error, a filtering routine was developed. The routine has seven steps, each one acting over different errors. At the first step, positioning errors are eliminated from the data set. The steps from 2 to 5 eliminate points with null or no yield, null or no grain moisture, points with swath width different from the total swath width and points with null distance. The sixth step acts over the filling time error, eliminating all points recorded during the space required for filling up the threshing mechanism of the combine. A search algorithm was developed to identify and eliminate these errors. The seventh step state outlier limits and remove from the data set the values outside of the limits. The filtering process improved the semivariance analysis and the final quality of yield maps.

Esta tese tem por objetivo estudar a precisão de uma nova estrutura robótica para operações de fresamento, em substituição às convencionais maquinas-ferramentas seriais, especialmente as fresadoras e os centros de usinagem CNC. A estrutura proposta está baseada no conceito da cinemática paralela, tendo a análise da precisão sido realizada em função do mapeamento dos erros de posicionamento da ferramenta de corte dentro do espaço de trabalho disponível, durante operação de fresamento de acabamento, aplicando modelagem matemática. A motivação está na busca por altos desempenhos e as estruturas robóticas paralelas possuem diversas vantagens perante as estruturas seriais: construção modular, massa reduzida, altas velocidades/acelerações. Por outro lado, há ainda problemas a serem solucionados, como: garantia da precisão, otimização do espaço de trabalho e redução/eliminação de singularidades. A metodologia aplicada no desenvolvimento deste trabalho compreende quatro etapas: a proposta de uma nova estrutura robótica desenvolvida a partir de métodos de síntese existentes; o desenvolvimento de modelos matemáticos para caracterizar o seu comportamento cinemático; a identificação das fontes de erro que influenciam no desvio de posição da ferramenta; a elaboração de modelos matemáticos e algorítmos computacionais para analisar o grau de influência de cada fonte de erro identificada. Desenvolvemos uma estrutura robótica de topologia assimétrica 2UPS+PRP, com as seguintes características: mobilidade 3 com três translações no espaço, reduzido número de componentes e movimento na direção z independente dos movimentos nas direções x e y. Apresentamos os algoritmos computacionais para mapear os erros cinemáticos, geométricos e elásticos através da discretização do espaço de trabalho disponível, baseado nas matrizes Jacobianas e no princípio do trabalho virtual. Com relação aos mapeamentos dos desvios de posição da ferramenta obtidos, chegamos a algumas conclusões. Os maiores erros cinemáticos ocorreram quando as imprecisões impostas aos dois membros motores laterais tinham sinais contrários. Os erros geométricos com tolerâncias dimensionais na classe de trabalho IT5, foram os mais relevantes dentre os erros considerados. Os erros elásticos, considerando forças de usinagem de acabamento, foram os menos relevantes entre os erros considerados, sendo expressiva a influência da rigidez das juntas universais e esféricas. A utilização do princípio do trabalho virtual, com parâmetros de rigidez concentrados, mostrou ser eficaz e eficiente, comparado ao SMA (análise da matriz estrutural) e ao FEM (método dos elementos finitos), devido ao menor trabalho para o desenvolvimento da sua formulação e ao tempo computacional reduzido para o seu processamento. / This thesis has the purpose to study the precision of a new robotic structure for milling operations, in substitution to the conventional serial machine-tools, specialy the CNC milling machines and cutting centers. The proposed structure is based on the parallel kinematics concept and the precision analysis was realized, applying mathematical models, to obtain the positioning errors mapping of the cutting tool in the available workspace, during finishing milling operations. The motivation is on the search higher performances and the parallel robotic structures have several advantages to the serial structures: modular construction, lightness, high velocities/acelerations. Otherwise, there are still problems to be solved, like: guaranty of precision, workspace optimization and reduction/elimination of singularities. The methodology applied for the development of this work involves four steps: the proposal of a new robotic structure developed using existing synthesis methods; the development of mathematical models to characterize its kinematic behavior; the error sources identification that influences the deviation of the tool position; the elaboration of mathematical models and computer algorithms to analyse the influence level of each identified error source. We developed one assymmetric robotic structure 2UPS+PRP, with the following characteristics: mobility 3 with three translations in the space, reduced number of componentes and displacement in z direction independent from the displacents in the x and y directions. We presented the computer algorithms to map the kinematic, geometric and elastic errors, throw the discretization of the available workspace, based on the Jacobian matrices and the virtual work principle. With regard to the tool position deviation mappings obtained, we reach to some conclusions. The major kinematic errors occurred when the imprecisions imposed to the two lateral actuatores had opposed signals. The geometric errors with dimensional tolerances in the IT5 work class, were the more relevant among the considered errors. The elastic errors, considering finishing manufacturing forces, were the less relevent among the considered errors, being expressive the influence of the rigidity of the universal and spherical jounts. The utilization of the virtual work principle and concentrated rigidity parameters, showed to be efficacious and efficient, compared to the SMA (astructural matrice analisis) and the FEM (finite elements methode), because of the minor work to develop its formulations end the reduced computer time to its prosecution.

A agricultura de precisão é um conjunto de tecnologias que prevê o manejo espacializado dos fatores de produção, baseado em informações coletadas e georeferenciadas. O mapa de produtividade é uma informação importante, pois materializa a resposta da cultura a todos os fatores. Diversos monitores de produtividade comerciais estão disponíveis no mercado para a coleta de informações de produtividade de forma bastante adensada. Devido à automação e à alta quantidade de informações, diversos erros ocorrem no processo de coleta e a retirada destes erros é um fator de qualidade da informação. A proposta do trabalho é desenvolver uma rotina de filtragem de dados brutos que elimine erros presentes em mapas de produtividade. Como primeira etapa do desenvolvimento do processo de filtragem, foi realizada a análise e caracterização dos erros presentes em seis mapas de produtividade provenientes de seis diferentes monitores de produtividade comerciais. Erros de posicionamento foram encontrados, representados por pontos fora do talhão, sendo que pequenos erros de posicionamento não podem ser detectados pela metodologia desenvolvida. Foram encontrados pontos com produtividade nula, umidade de grãos nula ou ausente e pontos com posição repetida. Pontos coletados com largura de plataforma de corte diferente da total foram considerados erros de medição de área, pois carregam a influência do operador na definição da largura da plataforma de corte efetivamente utilizada. Para a caracterização do erro de intervalo de enchimento foi desenvolvida uma metodologia para identificar o sentido de deslocamento da colhedora, possibilitando assim, a medição do espaço necessário para que o monitor esteja sensível às variações naturais da produtividade. A distância percorrida durante o intervalo de enchimento variou de 0 a 44m. Foram estabelecidos limites estatísticos para discrepância de valores de produtividade, sendo que foram encontrados pontos com valores de produtividade fora dos limites estabelecidos. Com base nas características de cada tipo de erro, foi desenvolvida uma rotina de filtragem de dados brutos. A rotina consistiu de 7 etapas, sendo que cada uma age sobre determinado tipo de erro de acordo com suas características. Na primeira etapa são retirados do conjunto pontos com erro grosseiro de posicionamento, representados por pontos fora dos limites do talhão. As etapas de número 2 a 5 consistem na retirada de pontos com produtividade nula ou ausente, pontos com largura de plataforma de corte diferente da total, pontos com umidade nula ou ausente e com distância nula entre pontos. A sexta, age sobre pontos gravados durante o intervalo de enchimento, tendo por base a distância referente ao erro e o número de pontos gravados durante tal distância. Foi desenvolvido um algoritmo de busca, identificação e eliminação dos pontos gravados durante o intervalo de enchimento. A sétima etapa estabelece limites estatísticos para discrepância de valores de produtividade e elimina pontos fora destes limites. De maneira geral, a filtragem de dados melhorou a modelagem da dependência espacial e elevou a qualidade final dos mapas de produtividade. / Precision farming is a set of technologies that provide the capacity to manage the yield based on spacialized information. Yield map is an important information as it describes the answer of the crop to the inputs and soil conditions. There are several yield monitors in the market to collect yield information automatically. Due to the automation of the collection, some errors may be collected together with good data, and the elimination of those errors from the data set represents information quality. This work proposes the development a filtering routine of raw data to eliminate errors. The first step is the analysis and characterization of the errors present on data from six different commercial yield monitors. The errors found are positioning errors, represented by points outside the field. Small positioning errors cannot be detected by this methodology. It was found points with null or no yield, null or no grain moisture and points with the same position. Points with swath width different from the total swath width were considered as area measuring errors because they take account the interpretation of the operator about the actual swath width. For the characterization of the combine filling time it was developed a methodology to identify the running direction of the machine, allowing the estimation of the distance required to fill the threshing mechanism of the combine. The distance during the filling time was found to be between 0 and 44m. Yield outlier limits were established, and values over and under the limits were found in the data. Based on the characteristics of each error, a filtering routine was developed. The routine has seven steps, each one acting over different errors. At the first step, positioning errors are eliminated from the data set. The steps from 2 to 5 eliminate points with null or no yield, null or no grain moisture, points with swath width different from the total swath width and points with null distance. The sixth step acts over the filling time error, eliminating all points recorded during the space required for filling up the threshing mechanism of the combine. A search algorithm was developed to identify and eliminate these errors. The seventh step state outlier limits and remove from the data set the values outside of the limits. The filtering process improved the semivariance analysis and the final quality of yield maps.

São inúmeras as atividades que fazem uso do sistema Global Navigation Satellite System - GNSS, sendo o Global Positioning System - GPS, desenvolvido pelos Estados Unidos, o mais utilizado. Na área de agricultura de precisão há a necessidade de posicionamento estático e cinemático com demandas de distintos níveis de acurácia e precisão para diferentes aplicações. A deficiência de informações técnicas dos fabricantes causa incertezas nos usuários, quanto à classe de receptor a ser utilizado para determinadas atividades agrícolas. Por esses motivos os objetivos deste trabalho foram: avaliar o uso de correções diferenciais através de ensaio estático, testar o uso do receptor GPS RTK como referência para avaliar o desempenho de receptores de baixo custo em condição cinemática e desenvolver uma plataforma instrumentada para avaliar os receptores de GPS sob condição cinemática representativa para operações agrícolas. No primeiro caso foram realizados ensaios com oito receptores, sobre uma torre livre de impedimentos físicos, na qual foi montada uma plataforma em formato de cruz e nos receptores foram ativadas e desativadas as correções diferenciais WAAS, EGNOS, SF1 e SF2 e também testadas as várias intensidades de filtragem disponíveis em alguns dos receptores. No ensaio cinemático utilizando um receptor GPS RTK como referência foram utilizados dois receptores de navegação, fixados sobre a cabine de um trator e foram coletados dados com diferentes freqüências. Para ensaios cinemáticos foi construída uma plataforma móvel instrumentada com um detector óptico de pulsos (encoder), um sensor foto elétrico e dois coletores de dados responsáveis por realizar o sincronismo entre os pulsos do encoder e as atualizações da sentença do GPS e armazenamento dos dados. Assim foi possível determinar as coordenadas de referência para o cálculo dos erros de precisão e acurácia do receptor GPS submetido à avaliação. Na avaliação dos receptores em ensaio estático os resultados mostraram que as correções WAAS e EGNOS não adicionam qualidade ao posicionamento na região de Piracicaba, SP. Com a ativação dessas correções os erros de precisão e de acurácia aumentaram. As correções diferencias SF1 e SF2 via satélite demonstraram ser mais acuradas que os demais sistemas ensaiados. O ensaio sob condição cinemática, com GPS RTK de referência, permitiu o cálculo de erros somente no sentido perpendicular ao percurso. A plataforma instrumentada funcionou, cumprindo as expectativas e permitindo o cálculo dos erros de precisão e acurácia, porém demonstrou problemas de robustez nos coletores de dados, necessitando de pequenas melhorias. / The activities that use the Global Navigation Satellite System - GNSS, are countless, and the Global Positioning System - GPS, developed by the United States is the most used today. In precision agriculture there is a need of static and cinematic positioning with demands of distinct levels of accuracy and precision for different applications. Technical information deficiencies from the manufacturers causes uncertainties to the users, as the receiver class to be used for certain agricultural activities. For these reasons the objectives of this work were: evaluate the use of differential corrections through static test, to test the use of RTK GPS as reference to evaluate the performance of low cost receivers under cinematic condition and develop an instrumented platform to evaluate GPS receivers under cinematic condition that represents agricultural operations. In the first case were realized tests with eight receivers, in the top of a tower free of physical obstacles, where it was mounted a platform with cross shape. The differential corrections WAAS, EGNOS, SF1 and SF2 were tested and also some intensities of filtering available in some of the receivers. In one of the cinematic tests, using a RTK GPS as reference, we used two navigation receivers, fixed over a tractor cabin and the data were collected with different frequencies. For the second cinematic test it was built a moving platform instrumented with a pulse optical detector (encoder), a photoelectric sensor and two data loggers, responsible for the synchronization between the encoder pulses and the GPS strings, and also log the data. With that it was possible to determine the reference coordinates to calculate the errors of precision and accuracy of the GPS receiver submitted to evaluation. The evaluation in static way showed that the corrections WAAS and EGNOS do not work in the region of Piracicaba, SP. Activating these corrections the precision and accuracy errors increased. The data collected with the satellite differential corrections SF1 and SF2 got closer to the real coordinate than the other evaluated systems. The test under cinematic condition, with the RTK GPS as reference, allowed the errors calculation only in the perpendicular direction of the course. The instrumented platform worked, accomplishing the expectation and allowing the errors calculation of precision and accuracy, however, showed problems of robustness in the data loggers, needing some improvement.

Precision dairy technologies (PDT) are becoming more accessible and are therefore becoming more common on commercial dairy farms and in dairy research. Prior to any use of PDT, one should understand the precision, accuracy and bias of the device by a validations studies before interpreting the behavior measurements. Thus, the objective of the first section of my thesis is to validate ruminating, feeding and resting measurements of a behavior monitoring collar used in the second section. Precision dairy technology is used in heat stress studies to compare behavior of cows exposed to different heat stress treatments or abatement strategies. Heat stress is an important issue to research because it negatively affects cow behavior, physiology, and therefore production in lactating dairy cows. The objective of the second section is to assess the ability of a free choice soaker to reduce heat stress measured utilizing PDT and compare use of a free choice to a soaker in addition to one of the two treatments 1) no mandatory soakings, or 2) two mandatory soakings.

Orientador: Zacarias Xavier Barros / Banca: Paulo Roberto Arbex Silva / Banca: Carlos Eduardo de Mendonça Otoboni / Resumo: A aerofotogrametria com Veículo Aéreo Não Tripulado (VANT), tem se tornado uma grande fonte de informações em diversas áreas da atividade econômica mundial, entre elas a agricultura de precisão. O Brasil, destacando-se como o maior produtor mundial de cana-de-açúcar, apresenta nesse segmento um grande mercado consumidor de geoinformação, sobretudo no que diz respeito a mapas de plantio da lavoura para orientação de piloto automático. Esta dissertação parte da hipótese de que um determinado produtor rural necessita mapear as linhas de plantio de sua lavoura e, para isso, pretende valer-se de técnicas de aerofotogrametria com VANT. Portanto, a metodologia mais eficiente deve ser aplicada visando à redução dos custos operacionais para viabilizar o investimento. Foram mapeados três talhões em diferentes estágios de desenvolvimento da lavoura, 40, 80 e 110 cm de altura, e cada um desses talhões foi sobrevoado com três alturas de voo, 70, 110 e 150 metros. Ao final deste experimento concluiu-se que quanto maior a altura de voo, menor é o custo computacional para obtenção da ortofoto e menor é a resolução do produto, o que ocasiona dificuldades na identificação das linhas de plantio. Conclui-se que nos estágios iniciais de desenvolvimento a cultura deve-se utilizar um GSD de no máximo 5cm/pixel para observar-se o contraste entra as plantas e o solo. Já para estágios mais avançados, com a lavoura entre 80 e 110 centímetros os GSD de 6,5 cm/pixel entregaram produtos aptos a identifica... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Unmaned Aerial Vehicle Photogrammetry has become a major source of information in many areas of worldwide economic activity, including precision agriculture. Brazil, standing out as the world's largest producer of sugarcane, presents in this segment a large consumer market for geoinformation, especially with regard to crop planting maps for automatic pilot guidance. This dissertation is based on the hypothesis that a farmer needs to map the planting lines of his crop and for this he intends to use aerophotogrammetry techniques with UAV. Therefore, the most efficient methodology should be applied in order to reduce operating costs to make the investment viable. Three plots were mapped at different stages of development of the crop, 40, 80 and 110 cm, and each of these plots were flown at three flight heights, 70, 110 and 150 meters. At the end of this experiment it was concluded that the higher the flight height, the lower the computational cost to obtain the orthophoto and the lower the product resolution, which causes difficulties in the identification of the planting lines. It is concluded that in the early stages of development the crop should use a maximum GSD of 5cm / pixel to observe the contrast between plants and soil. Already for more advanced stages, with the crop between 80 and 110 cm the GSD of 6.5 cm / pixel delivered products able to identify the planting lines. / Mestre

Healthy aging influences peripheral and central levels of the neuromotor system. These age-related changes contribute to the decline in dexterous manual behavior. Difficulty in performing activities of daily living increases reliance on external assistance. Understanding specific mechanisms leading to the decline in fine manual performance is crucial for their rehabilitation. In this thesis, we have attempted to increase our awareness of the causes underlying manual disability in old age. The first study investigated how old adults apply forces and moments on a freely-movable object using a precision grip (thumb and index finger) during functionally-relevant tasks. During the grasp-lift task old adults misaligned their thumb and finger contacts and produced greater grip force, greater external moments on the object around its roll axis, and oriented force vectors differently compared with young adults. During a precision-orientation task of inserting a slot on the object over a bar (`key-slot' task), old adults were more variable in digit-tip force directions and performed the key-slot task more slowly. With practice old adults aligned their digits, reduced their grip force, and minimized external moments on the object. We conclude that with old age comes with a reduced ability to control the forces and moments applied to objects during precision grasp and manipulation. This may contribute to the ubiquitous slowing and deteriorating manual dexterity in healthy aging. Another study investigated the effects of transcranial direct current stimulation (tDCS) to the contralateral M1 combined with motor training (MP) on changes in the forces applied to the object during grasp and manipulation. We also measured performances on functional tasks in healthy elderly individuals. Our results indicate that anodal tDCS+MP facilitates retention of learning on a skillful manual task in healthy old adults. Furthermore, improved retention on the pegboard test was associated with reduced force variability on the key-slot task that demanded similar precise control over the forces applied to the object. These findings suggest that the improvement in force steadiness is one of the potential mechanisms through which short-term anodal tDCS during motor training improved performance on a functional task that outlasted the intervention period. Furthermore, anodal tDCS over M1 in combination with motor practice also influenced motor response to tasks that critically depend on sensory signals in healthy old adults. Finally, we found that, in healthy elderly individuals, the memory representations scaling the lift force for the grip and lift task generalized, while the training-based learning on the ballistic task showed an incomplete transfer to the contralateral hand. These differences may indicate task-dependent interhemispheric transfer of learning in old age. Collectively, the work presented in this thesis demonstrates that the performance on dexterous manual tasks in healthy old adults may depend on how they configure their grasp, and control their finger forces (both linear and rotational) applied to the grasped object, specifically how smooth is the applied force.

Subsoil compaction is a major yield limiting factor for most agricultural crops. Tillage is the most efficient method to quickly treat compacted subsoil, but it is also expensive, increases erosion, and accelerates nutrient cycling. The use of real-time electrical conductivity (EC) and near-infrared (NIR) reflectance values to differentiate compacted areas from uncompacted areas was studied. This method has potential to reduce monetary and time investments inherent in traditional grid sampling and the resultant deep tillage of an entire field. EC and NIR reflectance are both very sensitive to spatial variability of soil attributes. The objective of this research was to determine whether the amount of soil moisture affects the efficacy of EC and NIR spectroscopy (at 2151.9 nm) in identifying subsoil compaction through correlation analysis, and also to determine whether a minimum level of compaction was necessary for these same methods to detect compaction in three different soil textures across a variable water gradient. Bulk density measurements were taken in late 2007 from plots traversing an induced soil moisture gradient, and low, medium, and high levels of compaction at three locations with different soil textures. A Veris Technologies (Salina, KS) Near-Infrared Spectrophotometer equipped with an Electrical Conductivity Surveyor 3150 was used to measure and geo-reference EC and NIR reflectance data over the same plots. Analysis of the data for a correlation between compaction (bulk density values) and EC, as well as compaction and NIR reflectance, produced clear results. It was found that electrical conductivity is not significantly different between compacted or uncompacted soils even when tested at all moisture extremes and in different soil textures in Utah. Also, NIR spectroscopy was unsuccessful at identifying subsoil compaction because all tested procedures to induce a spectrometer into the soil resulted in changes the physical properties of the soil.

This research examined three components of precision teaching; charting, timed practices, and performance aims. In the first study beginner skaters performed two roller skating skills, forward crosses and back scissors, with the aim of increasing fluency in these skills using precision teaching methods. Skaters were told to perform the skills as fast as they could during 1-min practises, aiming at a set performance aim, or goal. After each timing skaters were told how many repetitions they had performed. One group charted back scissors only and the other forward crosses only. The skaters became faster in both skills and charting did not produce faster rates. The improvement seen may have been a direct result of the performance aims. Therefore the second study, using back crosses, compared a fixed, difficult performance aim (complete 50 per minute) for one group and an easier, flexible performance aim (beat your previous sessions' high score) for a second group. After each timing skaters were told how many back crosses they had performed. Performance rates increased similarly for both groups, thus the different performance aims did not have different effects, contrary to the goal-setting literature. A third study investigated this further. Skaters performed forward crosses and back scissors during a baseline condition, where there were no performance aims or feedback. Increases in performance rates for both skills occurred. In a second condition, a performance aim higher than their number of repetitions in the previous condition was set and feedback was given for one skill only. There was an immediate increase in rate of the targeted skill for 3 of the 4 skaters, suggesting that the goal, when given with feedback, influenced the rate at which the skaters performed the skill. In the fourth study, where the effect of feedback and practice was examined more closely, soccer players dribbled a ball in and out of cones. As expected those who took part in eight to ten sessions that were told to do their best (an easy goal) and not given feedback performed this skill faster than those who completed only two sessions with the same conditions. Unexpectedly, they also performed faster than those set a performance aim of beating their previous highest score (a hard goal) and who were given feedback. Methodological issues that may have been responsible for this latter result were addressed in the fifth study. Skaters completing 10 sessions of forward crosses, with feedback and with a performance aim of completing 60 repetitions in one minute (a hard goal), became faster than skaters completing 10 sessions without feedback who were told to do their best. Skaters told to do their best, who completed only three sessions without feedback, did not get faster. These results support those in the goal-setting literature that, hard goals with feedback have more effect than being told to do your best. Overall these studies show that short, timed practices and hard performance aims, or goals, may be effective components of precision teaching while visual feedback from charting may not. Further, precision teaching methods were effective when applied to sporting skills such as those used by roller skaters and soccer players for building fluency of basic skills.