The Bereitschaftspotential (BP) is an event related potential believed to reflect motor planning and preparedness. Although the relationship between the BP and volitional movements of the distal limbs is well established, studies of the BP and speech have produced inconclusive findings. The most heavily debated of these findings were reports of left lateralized hemispheric asymmetry in the BP topography, shortly before speech onset. Several researchers argued that these shifts were artifacts produced by movements of the articulatory muscles. However, methodological differences between the studies could also explain why the asymmetry was not always found. In the present study it was proposed that articulatory complexity and semantic processing each contribute to observed variations in the speech BP topography. Eighteen healthy volunteers performed 3 speech tasks, designed to distinguish semantic and articulatory contributions to the BP topography. The findings suggested that articulatory complexity and semantic processing each uniquely contribute to the frontolateral and medial BP topographic distribution. The present study also introduced the use of Doppler imaging of the tongue as a means of eliminating potential artifactual tongue movements from the speech BP. / Ph. D.

Both the brain and the individual’s environment contribute to the intertwined trajectory of developmental domains across the lifespan. The primary aim of this dissertation was to examine developmental cascades in autism through this combined perspective. First, we systematically investigated how neuroimaging techniques have been used to identify neuroanatomical and neurophysiological differences in infants with an elevated likelihood of developing autism. We found that, in addition to these distinct structural and functional differences, neuroimaging provides a novel opportunity to examine how these differences relate to developmental trajectories across a variety of domains. Second, we focused on assessing gross motor performance in autistic children within their home environment, and relating this performance to standardized measures of movement, adaptive behavior, and communication skills. We found notable levels of variability in gross motor performance, and significant relationships between these measures and measures of adaptive behavior. Finally, through an embodied cognition, developmental systems approach, we assessed the feasibility of using both neuroimaging and lab-based tasks to assess the relationship between cognitive and motor performance in autistic children. We designed and executed a novel study using functional near-infrared spectroscopy during a dual-task walking paradigm and found that, while the paradigm itself produces promising preliminary data, several aspects of the study design may need to be reconsidered in order to ensure feasibility across all participants. Combined, these findings suggest that we can best understand the relationships between developmental domains in autism through a multifaceted lens. This research provides foundational groundwork for comprehensive autism research methods and paves the way for identifying and supporting autistic children’s individual differences, both across the spectrum and within intersecting developmental domains. / 2026-08-19T00:00:00Z

Thesis (Ph.D.)--Boston University / PLEASE NOTE: Boston University Libraries did not receive an Authorization To Manage form for this thesis or dissertation. It is therefore not openly accessible, though it may be available by request. If you are the author or principal advisor of this work and would like to request open access for it, please contact us at open-help@bu.edu. Thank you. / This study examined certain aspects of the relationship between appropriateness of emotional response and delay of motor behavior. It related two different ego functions ia terms of a more general principle of ego control. Theoretical formulations were derived from Rapaport's unification of a whole array of ego functions by means of the concept of ability to delay. Delay entails inhibition of impulsive reactions and a complex differentiation and control process culminating in adaptive action. There is presumably an organized control system such that an individual is quite self-consistent in exercising control in various contexts. A review of pertinent studies revealed considerable support for the existence of generalized delaying capacity. Evidence of interrelationships among measures of motor inhibition, cognitive inhibition, and inhibition of the behavioral expression of an affect was cited. [TRUNCATED] / 2999-01-01

This works systematically presents various strategies to reduce both differential mode (DM) and common mode (CM) noise using a passive filter in a dc-fed motor drive. Following a standard approach a baseline filter is first designed to be used as reference to understand and compare the available filter topologies. Furthermore, it is used to analyze the grounding scheme of EMI filter and more specifically provide guidelines to ground single or multi stages filter. Finally, the baseline filter is investigated to recognize the possible solutions to minimize the size of the whole filter. It turns out that the CM choke and DM capacitors are the two main downsides to achieve a small EMI filter. Therefore, ideas are proposed to improve the CM choke by using other type of material such as nano crystalline core, different winding technique and new integrated method. A material comparison study is made between the common ferrite core and the nano crystalline core. Its advantages (high permeability and saturation flux density) and drawback (huge permeability drop) are analyzed thought multitudes of small and large signals tests. A novel integrated filter structure is addressed that maximizes the window area of the ferrite core and increases its leakage inductance by integrating both CM and DM inductances on the same core. Small- and large-signal experiments are conducted to verify the validity of the structure showing an effective size reduction and a good improvement at low and high frequencies. To conclude, a final filter version is proposed that reduce the volume of the baseline filter by three improve the performances in power tests. / Master of Science

Visual-motor integration, visual perception and motor co-ordination contribute to successful academic, school and career life. Literature also indicates that delays in the skills in above mentioned abilities could lead to delays in the mastering of object control skills. Furthermore, due to the developing needs of South Africa, there is a range of socio-economic challenges, and the effects on the above mentioned skills seem to lack development. Due to the possible effect that visual skills can have on academic performance, it seems important to further investigate the effect it may have on sport skills as well. The aim of this study was firstly, to determine the effect of gender differences and school types associated with different socio-economic conditions on the visual-motor integration, visual perception and motor co-ordination abilities of Grade 1 boys and girls in the North West Province of South Africa. Secondly, the study aimed to determine the relationship between visual-motor integration, visual perception, motor co-ordination and object control skills of Grade 1-learners in the North West Province of South Africa. For the purpose of the first objective 816 participants (419 boys and 397 girls) were evaluated and for the second objective, 806 participants (413 boys and 393 girls) were evaluated. The test instrument used to determine the level of the participants’ visual-motor skills was the Developmental Test of Visual-Motor Integration – 4th ed. (VMI-4) which consisted of the visual- motor integration test and two subtests which included visual perception and motor co- ordination. The children’s object-control skills were tested with the Test of Gross Motor Development – 2 (TGMD-2) which is designed to test the gross motor functioning of children from 3 to 10 years old. The STATISTICA software package (StatSoft, 2013) was used to analyse data. Data was analysed by means of descriptive statistics as well as a variation analyses (ANOVA). ANOVA was used to determine the interaction effect between gender and/or socio-economic status and visual-motor integration, visual perception and motor co-ordination. Independent t-testing was used to determine the effect of gender differences and socio-economic status in visual-motor integration, visual perception and motor co-ordination. Effect sizes (d) were used to calculate practical significance of differences. Two-way frequency tables were used to compare the classifications of the different school quintiles (Quintile 1-3 = schools associated with low socio-economic status and Quintile 4-5 = schools associated with high socio-economic status) among the VMI-4-classes. The Pearson Chi-square was used to indicate the significance of the differences and the level of statistical significance was set at p≤0.05. Furthermore a Spearman rank order correlation was used to determine the correlations among visual-motor integration, visual perception, motor co-ordination, striking a stationary ball, stationary dribble, catch, kick, underhand rolling and overhand throw, and an object control total. The results revealed that gender had no significant effect on visual-motor integration, visual perception and motor co-ordination within the respective school types associated with different socio-economic conditions. Although there were no significant differences between the boys and girls, statistically significant higher mean scores were found in school types associated with higher socio-economic status (Quintile 4 and 5) with regard to visual-motor integration, visual perception and motor co-ordination. The object control skills total had small and medium correlations with visual- motor integration, visual perception and motor co-ordination. Visual perception had the highest correlation with the object control skills total. These results contribute to our understanding of the influence that visual-motor integration, visual perception and motor co-ordination have on sport skills and more specifically ball sport skills. This knowledge enables researchers to better address problems which present in early years with regard to visual skills, as well as the negative impact which low socio-economic circumstances have on these skills in order to improve academic and sport skills later. / MA (Child Kinetics), North-West University, Potchefstroom Campus, 2015

Visual-motor integration, visual perception and motor co-ordination contribute to successful academic, school and career life. Literature also indicates that delays in the skills in above mentioned abilities could lead to delays in the mastering of object control skills. Furthermore, due to the developing needs of South Africa, there is a range of socio-economic challenges, and the effects on the above mentioned skills seem to lack development. Due to the possible effect that visual skills can have on academic performance, it seems important to further investigate the effect it may have on sport skills as well. The aim of this study was firstly, to determine the effect of gender differences and school types associated with different socio-economic conditions on the visual-motor integration, visual perception and motor co-ordination abilities of Grade 1 boys and girls in the North West Province of South Africa. Secondly, the study aimed to determine the relationship between visual-motor integration, visual perception, motor co-ordination and object control skills of Grade 1-learners in the North West Province of South Africa. For the purpose of the first objective 816 participants (419 boys and 397 girls) were evaluated and for the second objective, 806 participants (413 boys and 393 girls) were evaluated. The test instrument used to determine the level of the participants’ visual-motor skills was the Developmental Test of Visual-Motor Integration – 4th ed. (VMI-4) which consisted of the visual- motor integration test and two subtests which included visual perception and motor co- ordination. The children’s object-control skills were tested with the Test of Gross Motor Development – 2 (TGMD-2) which is designed to test the gross motor functioning of children from 3 to 10 years old. The STATISTICA software package (StatSoft, 2013) was used to analyse data. Data was analysed by means of descriptive statistics as well as a variation analyses (ANOVA). ANOVA was used to determine the interaction effect between gender and/or socio-economic status and visual-motor integration, visual perception and motor co-ordination. Independent t-testing was used to determine the effect of gender differences and socio-economic status in visual-motor integration, visual perception and motor co-ordination. Effect sizes (d) were used to calculate practical significance of differences. Two-way frequency tables were used to compare the classifications of the different school quintiles (Quintile 1-3 = schools associated with low socio-economic status and Quintile 4-5 = schools associated with high socio-economic status) among the VMI-4-classes. The Pearson Chi-square was used to indicate the significance of the differences and the level of statistical significance was set at p≤0.05. Furthermore a Spearman rank order correlation was used to determine the correlations among visual-motor integration, visual perception, motor co-ordination, striking a stationary ball, stationary dribble, catch, kick, underhand rolling and overhand throw, and an object control total. The results revealed that gender had no significant effect on visual-motor integration, visual perception and motor co-ordination within the respective school types associated with different socio-economic conditions. Although there were no significant differences between the boys and girls, statistically significant higher mean scores were found in school types associated with higher socio-economic status (Quintile 4 and 5) with regard to visual-motor integration, visual perception and motor co-ordination. The object control skills total had small and medium correlations with visual- motor integration, visual perception and motor co-ordination. Visual perception had the highest correlation with the object control skills total. These results contribute to our understanding of the influence that visual-motor integration, visual perception and motor co-ordination have on sport skills and more specifically ball sport skills. This knowledge enables researchers to better address problems which present in early years with regard to visual skills, as well as the negative impact which low socio-economic circumstances have on these skills in order to improve academic and sport skills later. / MA (Child Kinetics), North-West University, Potchefstroom Campus, 2015

Thesis (MScEng)--University of Stellenbosch, 2001. / ENGLISH ABSTRACT: To reduce exhaust gas emissions in diesel engines and for engine upgrade purposes the major parameters and equipment that should be looked at are boost pressure, intake charge temperature, combustion chamber design and fuel injection equipment. Boost pressure is governed by the turbo-charger; with high-efficiency variable geometry turbochargers, effective control is possible to increase airflow rate at all operating conditions of the engine. Efficient air-to-air inter-cooling results in the engine being filled with a cooler air charge that will influence engine durability and heat rejection to the cooling system. The main objective of the investigation is to look at the influence of boost pressure and intake charge temperature on diesel combustion to better understand the processes where boost pressure is increased and intake charge temperature reduced to increase the brake mean effective pressure of the engine and reduce emissions generation. By running an engine at different intake boost pressures and intake charge temperatures a 25-point matrix was formed at three different operating conditions. On completion of the engine testing, data processing and data evaluation, a number of important conclusions were made about the behaviour of the engine running under different conditions. This enabled the researcher to understand how boost pressure and intake charge temperature influence engine power output, fuel consumption, engine durability and exhaust gas emissions. The opinion is proved when, in most cases, the 75 test points were used to build multiple linear regression models to determine which engine parameters (dependent variables) have a significant effect on emissions generation and durability parameters. From the data it is evident that boost pressure has a positive influence on most engine parameters, as an increase in boost pressure results in an increase in air mass flow through the engine. An increase in air mass flow reduces combustion chamber gas temperature as the result of an increase in excess air ratio during combustion. A further result of the increase in excess air ratio is that less soot is formed during the first part of combustion and more soot and partly decomposed Hydrocarbon (HC) compounds are oxidised during the late combustion phase. Therefore, with an increase in boost pressure, Bosch smoke emissions reduce, but with a change in intake air temperature no difference in smoke concentration is seen except at the very low boost pressure and very high boost temperature test points where low air/fuel ratios exist and the slight increase in air-flow rate as a result of lower air inlet temperature has a big influence. Nitric Oxide (NO) emissions, on the other hand, are more dependent on intake air temperature than on boost pressure, which was proved in the multiple regressions modelling performed on the test data. The flame zone and the post-flame zone temperature play the dominant role in NO formation. As explained in the results discussion on NO formation, intake air temperature influences the ignition mixture temperature and the subsequent flame zone temperature. A lower intake air condition results in longer ignition delay and increases the initial rate of combustion. / AFRIKAANSE OPSOMMING: Die hoofparameters en toerusting wat in ag geneem moet word om uitlaatgasemissies in dieselenjins te verminder en om enjinkraguitset te verhoog, is inlaatdruk, inlaat lugtemperatuur, verbrandingskamerontwerp en brandstofinspuittoerusting. Inlaatdruk word beheer deur die turb-aanjaer. Met hoë effektiwiteit, veranderlike geometrie turboaanjaging, is effektiewe beheer moontlik om lugvloei-tempo deur die enjin te verhoog onder alle enjinwerkstoestande. Effektiewe lug-tot-lug tussenverkoeling laat die enjin met koeler inlaatlug vul, wat 'n uitwerking het op enjinlewensduur en hitte-verlies na die verkoelingsstelsel. Die hoofdoel van die navorsing is om die invloed van inlaatdruk en inlaat lugtemperatuur op dieselverbranding te ondersoek. Sodoende kry die navorser 'n beter begrip omtrent die prosesse waar inlaatdruk verhoog en inlaat lugtemperatuur verlaag word, om rem-gemiddelde effektiewe druk van die enjin te verhoog en uitlaatgas emissies te verlaag. 'n 25-punt matriks is opgestel deur die enjin by verskillende inlaatdrukke en inlaat lugtemperture te opereer, en by drie verskillende wringkragwerkstoestande. 'n Aantal belangrike gevolgtrekkings is gemaak omtrent enjinwerking onder verskillende werkstoestande na voltooiing van die enjintoetse, dataverwerking en data-evaluering. Sodoende het die navorser bepaal hoe inlaatdruk en inlaat lugtemperatuur kraglewering, brandstofverbruik, enjinlewensduur en uitlaatgasemissies beïnvloed. Om bogenoemde begrippe verder te ondersteun is 'n meervoudige, lineëre regressiemodel opgestel om te bepaal watter enjinparameters (afhanklike veranderlikes) 'n wesenlike effek op emissiegenerasie en lewensduur het. Van die data word afgelei dat inlaatdruk 'n positiewe effek op die meeste enjinparameters het, omdat hoër inlaatdruk die lugvloeitempo deur die enjin verhoog. Hoër lugmassavloei verminder verbrandingsgastemperatuur as gevolg van 'n hoër oortollige lugverhouding tydens verbranding. 'n Verdere gevolg van 'n hoër oortollige lugverhouding is dat minder roet gevorm word gedurende die eerste verbrandingsfase en meer roet en gedeeltelik verbrande koolwaterstofverbindings oksideer gedurende die finale verbrandingsfase. Dus, met 'n hoër inlaatdruk word Bosch rookemmissies verlaag. Geen wesenlike verandering in rookkonsentrasies word egter gesien met 'n verandering in inlaatlugtemperatuur nie, behalwe by baie lae inlaatdruk- en hoë inlaat lugtemperatuur-toetskondisies waar lae lug/brandstofverhoudings bestaan en 'n klein toename in lugmassavloei as gevolg van laer inlaat lugtempertuur'n groot invloed het. Stikstofmonoksied (NO) emissies is meer afhanklik van inlaat lugtemperatuur as inlaatdruk. Dit is bewys in die meervoudige regressiemodel. Die vlamsone- en die navlamsone- temperatuur speel 'n groot rol in NO vorming. Inlaat lugtemperatuur beïnvloed die temperatuur van die onstekingsmengsel en die daaropvolgende vlamsonetemperatuur. 'n Laer inlaat lugtemperatuur veroorsaak 'n langer onstekingsvertraging en verhoog die aanvanklike verbrandingstempo.

Thesis (MScSportSc)--University of Stellenbosch, 2004. / ENGLISH ABSTRACT: The purpose of this investigation was to determine whether a sensory motor development programme could have an effect on some of the underlying physical and perceptual abilities that support school readiness. The control group consisted of 23 children and the two intervention groups of 79 children in total. All of the children were enrolled in a pre-primary school programme in a local community. They were all six years old by the end of the intervention. The Movement Assessment Battery for Children (Henderson & Sugden, 1992) was used to assess the children on their manual dexterity, eye-hand coordination, static balance and dynamic balance. The intervention programme consisted of two phases of 10 weeks each, during which the sensory motor development activities were presented to the two intervention groups. Results of the investigation revealed there were significant improvements for some of the children on selected variables that underlie school readiness. It can be concluded that participation in a sensory motor development programme can make a significant contribution to school readiness for many children. / AFRIKAANSE OPSOMMING: Die doel van hierdie ondersoek was om te bepaal of 'n sensories-motoriese ontwikkelingsprogram enige uitwerking op bepaalde onderliggende fisiese en perseptuele vermoëns wat tot skoolgereedheid by jong kinders bydra, sou kon hê. Die kontrolegroep het uit drie-en-twintig kinders bestaan. Die twee tussentredende groepe het altesaam uit nege-en-sewentig kinders bestaan. Die kinders was almal pre-primêre skoolprogramleerders vanuit 'n plaaslike gemeenskap. Teen die einde van die intrede het al die betrokke kinders sesjarige ouderdom bereik. Movement Assessment Battery for Children (Hendersen & Sugden, 1992) is as riglyn gebruik om die kinders se handvaardigheid, oog-hand-koërdinasie, statiese en dinamiese balans te evalueer. Die tussentredeprogram het bestaan uit twee fases van tien weke elk. Die sensoriese-motoriese ontwikkelingsaktiwiteite is terselfdertyd vir die twee tussentredegroepe aangebied. Die resultate van die ondersoek het beduidende vordering in sommige kinders getoon, spesifiek ten opsigte van bepaalde veranderlikes onderliggend aan skoolgereedheid. Hierdie bevinding dui daarop dat sodanige deelname in 'n sensories-motoriese ontwikkelingsprogram wel 'n betekenisvolle bydrae tot die ontwikkeling van skoolgereedheid in baie kinders kan maak.

Ao longo da infância e juventude se faz importante avaliar o desempenho motor para monitorar o desenvolvimento motor e subsidiar objetivos de intervenção. Há diversos instrumentos com o intuito de avaliar o desempenho motor de bebês, crianças e jovens, porém uma questão que é apontada na literatura diz respeito a especificidade de cada instrumento quanto ao seu contexto. Diversos instrumentos de avaliação motora têm sido desenvolvidos no decorrer do tempo, e muitos destes foram elaborados para mensurar o mesmo fenômeno no âmbito motor, no entanto, tais instrumentos podem apresentar resultados distintos para um mesmo objetivo. Desta forma, torna-se importante verificar se estes instrumentos permitem fazer o mesmo diagnóstico. Com isso, o presente estudo tem como objetivo investigar a associação entre o TGMD-2 e o KTK, considerando tanto o desempenho quanto o diagnóstico. A amostra do presente estudo foi composta por 228 crianças pertencentes ao Estudo Longitudinal Misto de Crescimento e Desenvolvimento Motor de Muzambinho-MG, contrabalanceadas por sexo e idade (6 a 11 anos de idade). Foram realizadas avaliações por meio dos testes KTK e TGMD-2. A análise dos filmes foi realizada por avaliadores treinados com índice de concordância inter e intra individual acima de 85%. Os valores obtidos indicaram que tanto o desempenho quanto o diagnóstico dos testes não são associados, mesmo considerando a idade e sexo dos sujeitos. Os resultados apresentam um novo cenário sobre a questão da avaliação motora na infância e permitiram discutir aspectos sobre a complementariedade das baterias quanto ao domínio do desenvolvimento motor na infância / Throughout childhood and youth becomes important to assess motor performance to monitor the motor development and support intervention goals. There are several tools in order to evaluate the motor performance of infants, children and young people, but an issue that is reported in the literature concerns the specificity of each instrument as to its context. Several motor assessment tools have been developed over time, and many of these are designed to measure the same phenomenon under motor development, however, such instruments may present different results for the same goal. Thus, it is important to check that these instruments allow you to make the same diagnosis. Thus, the present study aims to investigate the association between TGMD-2 and the KTK, considering both performance diagnosis. The study sample consisted of 228 children belonging to the Joint Longitudinal Study on Growth and Development of Motor Muzambinho-MG, counterbalanced by sex and age (6-11 years old). Evaluations were performed through the KTK and TGMD-2 tests. The analysis of the films was carried out by trained assessors with level of inter and intra individual above 85%. The results indicate that both the performance and the diagnosis of the tests are not associated, regardless of age and gender of the subjects. The results present a new scenario on the issue of motor assessment in childhood and allowed a discussion on the complementary aspects of the batteries on the motor development of the area in childhood

Determinação do desempenho de um motor à combustão interna com ignição por centelha, sem modificação em sua taxa de compressão volumétrica, usando álcool etílico vaporizado como combustível. Para facilidade de obtenção de dados usou-se um sistema de aquecimento elétrico para a geração do vapor do álcool etílico. Mediu-se as descargas de ar e combustível, a potência no eixo e a temperatura dos gases de escape para vários ângulos de avanço de centelha e rotações do eixo do motor. Os resultados obtidos foram comparados com o desempenho do mesmo motor funcionando com gasolina e álcool, pelo sistema de mistura usando carburador. O processo de vaporização pode ser aplicado a motores do tipo ciclo Otto , que poderão funcionar com álcool etílico ou gasolina, com poucas alterações em seu desempenho. / Performance determination of a spark-ignition combustion-engine, without modification in compression ratio, fueled with etanol vapours. The data acquisition was simplified by the use of an electric heater to generate the etanol vapours. The data acquired are flow of air and fuel, net power and escape gases temperature to various spark advance angles and engine speed. The performance was compared with those obtained with the carburator system motor, gasoline and etanol as fuel. The vaporization process will be applied in Otto cycle engines that may work with etanol or gasoline as fuels, with few performance alterations.