The purpose of this dissertation was to explore the potential use of net impulse and its characteristics in vertical jumping to monitor athletes' performance status and responses/adaptations to interventions. Five variables were proposed as net impulse characteristics: net impulse height and width, rate of force development, shape factor, and net impulse proportion. The following were then examined: 1) test-retest reliability of a new approach to identify net impulse in a force-time curve and of net impulse characteristics and criterion validity of the new approach; 2) effective measures of net impulse characteristics; 3) relationships between training-induced changes in its characteristics and force production ability. The following are major findings of the dissertation. Rate of force development particularly for the countermovement jump require a large magnitude of change to overcome the variable's inherent variability. Shape factor and net impulse proportion for the static jump should be used with caution and requires further investigations. Alternative net impulse can be used interchangeably to criterion net impulse. Of the proposed net impulse characteristics, net impulse height and width and shape factor were found to contribute to countermovement jump height, whereas all the net impulse characteristics were found to contribute to static jump height. Of the characteristics found to contribute, relative net impulse height (net impulse height divided by system mass) appears to be an important characteristic to achieve a high jump height for the countermovement and static jumps and net impulse proportion for the static jump. A mechanism behind increased countermovement jump height may be an increased countermovement displacement as a result of increased force production ability. A mechanism behind increased static jump height is the increased proportion of the entire positive impulse occupied by net impulse (i.e. increased net impulse proportion). The findings of this dissertation show the possibility of the use of the net impulse characteristics to monitor athletes' performance status and responses/adaptations to interventions. However, because this dissertation was the first to explore the potential use of the net impulse characteristics for athletes' performance monitoring, the existing knowledge is still preliminary and further research is required before practical recommendations are made.

Book Summary: Dizziness comes in many forms in each age group – some specific to an age group (e.g. benign paroxysmal vertigo of childhood) while others span the age spectrum (e.g., migraine-associated vertigo). This content organizes evaluation and management of the dizzy patient by age to bring a fresh perspective to seeing these often difficult patients.

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Underground coal mine explosions pose a significant threat to infrastructure such as mine seals and refuge alternative chambers. After a mine seal failed in the Sago mine disaster, which took the life of 12 miners, design requirements were reexamined and improved. However, most research being completed on the analysis of mine structures during an explosive event focuses solely on peak pressure values, while ignoring the impact of pressure duration. This study investigates the impact pressure duration, waveform shape, and impulse have on structural displacement, while also exploring what pressures and duration can be expected during a mine explosion. Additionally, the use of high explosives to simulation conditions experienced during a mine explosion is examined. Results from this study are produced through experimental testing using a scaled shock tube and theoretical studies using finite element analysis.

Adolescence is characterized as a time of impulsivity, emotional decision-making, and peer influence; thus, interventions targeting the development of effective psychosocial skills are imperative. Improved psychosocial functioning can equip adolescents for successfully overcoming future life challenges. There are few studies that have examined how adolescents' psychosocial skills could be improved in the context of substance abuse prevention program participation. The purpose of this study was to examine changes in psychosocial skills in a group of adolescents who participated in 2 of 10 Lions Quest Skills for Adolescence (Lions Quest SFA) programs being used in central Virginia middle schools. This study examined whether Lions Quest SFA was useful in observing changes in the total score of lagging psychosocial skills, which incorporated measures of impulse control, emotion regulation, and social skills. The adolescent population of interest had already demonstrated weaknesses in these areas as they had been referred to this program from school-based mental health services. This archival study used an ANCOVA to analyze 1-year pre- and posttest score differences on the Assessment of Lagging Skills and Unsolved Problems and examine possible gender differences following participation in the program for 1 school year. The secondary dataset consisted of pre- and posttest scores of 36 male students and 30 female students. The results of this study demonstrated implications for social change as they extended the knowledge in this area by suggesting that participation in the Lions Quest SFA program may contribute to the improvement of psychosocial skills, and these findings could contribute to the improvement of treatment interventions used at Horizon Behavioral Health.

The security of wireless networks and systems is becoming increasingly important as wireless devices are more and more ubiquitous nowadays. The wireless channel exhibits the spatial uncorrelation property, which is that the characteristics of a wireless channel become uncorrelated every half carrier wavelength over distance. This property has prompted an emerging research area that utilizes wireless channel characteristics to achieve location distinction, to detect location changes or facilitate authentication of wireless users, and to establish shared secret key between legitimate communicators. This dissertation includes two work toward the security improvement of existing wireless networks and systems. With the discovered channel camouflage and manipulation techniques in wireless networks, traditional wireless channel based authentication or secure communication systems are broke or renovated. The first work proposes a new attack against all existing location distinction approaches that are built on this spatial uncorrelation property. With the discovered attack, an attacker can easily bypass authentication or camouflage location changes by creating an artificial wireless channel similar to a legitimate one. This dissertation also presents a detection technique that utilizes an auxiliary receiver or antenna to identify these fake channels. On the other hand, the second work shows that the legitimate users can also benefit from constructing these artificial wireless channels and apply them in a novel wireless key establishment. The proposed technique enables the transmitter to specify any content as the secret key and securely deliver it to the target receiver, and meanwhile removes the reconciliation process which is necessary for conventional wireless key establishment schemes.

Introdução: danos ao sistema vestibular no nascimento ou na primeira infância podem ocorrer e impactar significativamente o desenvolvimento de uma criança em diversas áreas. A avaliação e o diagnóstico infantil na área da otoneurologia têm se revelado ainda como um desafio pela dificuldade de identificar as alterações vestibulares e pelo fato do desconforto dos exames vestibulares clássicos, que se potencializam para essa faixa etária. O avanço tecnológico tem proporcionado considerável progresso quanto à avaliação do reflexo vestíbulo-ocular (RVO) nessa população de modo menos invasivo e desconfortável por meio do video Head Impulse Test (vHIT). Objetivo: este trabalho se propõe a caracterizar o ganho do RVO para os canais semicirculares (CSC) horizontais e verticais em crianças hígidas quanto às variáveis sexo, diferença entre lados e faixa etária, bem como a aplicabilidade do vHIT. Metodologia: trata-se de um estudo clínico, observacional, transversal com análise de dados de modo descritivo e inferencial. Para a avaliação do RVO por meio do vHIT foi utilizado o equipamento Sistema de Impulso ICS Otometrics. A casuística incluiu 52 crianças hígidas na faixa etária de 5 a 10 anos de idade. Resultados: quanto ao ganho do RVO, observou-se diferença significativa em relação ao sexo para CSC posterior esquerdo, diferença significante do ganho entre lados para todos os CSC, mas não foi verificada correlação entre o ganho e a faixa etária. Em relação à aplicabilidade, foram observadas dificuldades na avaliação da população infantil no que diz respeito aos aspectos físicos e comportamentais, sendo comum a presença de artefatos nessa população. Conclusão: a caracterização do ganho do RVO para os CSC apresentou diferença significativa para a variável sexo, mas não para a variável faixa etária, e, quanto aos lados, verificou-se diferença significativa maior à direita. A caracterização da aplicabilidade do exame vHIT na população estudada evidenciou que apesar de demandar maior cuidado com a realização do exame, é possível minimizar efeitos causados pelos aspectos físicos e comportamentais, demonstrando que novas perspectivas da avaliação otoneurológica infantil são possíveis, tendo como aliado o vHIT. / Introduction: damage to the vestibular system at birth or in early childhood can occur and significantly impact the development of children in several areas. Otoneurologic evaluation and diagnosis in children are still a challenge due to the difficulty in identifying vestibular changes and the discomfort of typical vestibular assessments, which is worse for people in this age group. Technological advances have provided considerable progress in the vestibulo-ocular reflex (VOR) assessment of such population in a less invasive and more comfortable way through the video Head Impulse Test (vHIT). Objective: this research aims to lay out the VOR gain characteristics for horizontal and vertical semicircular canals (SCC) in healthy children regarding the gender, the difference between sides, and age range variables, as well as the applicability of the vHIT. Methods: this is a cross-sectional, observational, clinical study with descriptive and inferential data analysis. The ICS Otometrics Impulse System was used for evaluating VOR through the vHIT. The sample included 52 healthy children aged 5 to 10 years. Results: regarding the VOR gain, there was a significant difference between genders for left SCC and a significant difference of the gain between sides for all SCC, but no correlation between gain and age group was found. In regard to the applicability, difficulties were observed in the evaluation of the child population with respect to physical and behavioral aspects, and the presence of artifacts was common in that population. Conclusion: defining the VOR gain for SCC showed a significant difference for the gender variable, but not for the age group variable. Regarding the sides variable, there was a significantly greater difference on the right. The laying out of the vHIT exam applicability in the studied population showed that, despite demanding greater care with the assessment, it is possible to minimize effects caused by the physical and behavioral aspects, demonstrating that it is possible to have new perspectives on the otoneurological evaluation of children, and vHIT is a valuable tool in that sense.

La technique ultra large bande (UWB) par impulsions consiste à émettre des impulsions de courte durée et de faible énergie offrant ainsi la possibilité de transmettre de l'information à de hauts débits et à faible coût. Dans cette thèse nous nous sommes intéressés aux systèmes ultra large bande à accès multiple par répartition de codes de saut temporel (TH-UWB) dans un contexte asynchrone et dans un environnement de propagation à trajets multiples. Un récepteur rake a été mis en place. Nous avons calculé de manière analytique la variance de l'interférence multi-utilisateur (MUI) en sortie de ce récepteur. Ceci nous a permis d'identifier les paires dites optimales qui minimisent cette variance. Nous avons constaté qu'utiliser ces paires permet d'améliorer significativement le taux d'erreur binaire du système. Une démarche similaire a été appliquée aux systèmes DS-UWB et DS-CDMA, en effet ces systèmes s'expriment analytiquement de manière identique au système TH-UWB. Ainsi nous avons pu caractériser les paires optimales. Nous avons ensuite comparé les performances de ces différents systèmes lorsque la variance de la MUI est minimale. La variance de l'interférence entre symboles et entre trames (ISI / IFI) a été calculée analytiquement. Ceci nous a permis de dimensionner le récepteur rake et le temps de garde intelligemment. Nous avons également observé, en absence d'ISI / IFI et de bruit, un seuil sur la probabilité d'erreur. En modifiant légèrement le récepteur, nous avons éliminé ce seuil. Enfin nous avons établi les bornes de Cramer-Rao relatives à l'estimation des paramètres du canal (amplitudes et retards) en supposant que les trajets pouvaient se chevaucher.

<p>Our purpose with this research has been to obtain a deeper insight and understanding for the phenomenon and term “weekday-luxury.”</p><p>Through our research, we have found a link between value, service, brands and consumer behaviour into a relationship that we termed “weekday-luxury.” This link of values is particularly interesting to us and we are curious about the underlying motivation to “weekday-luxury” and the driving forces underlying the phenomenon. We have noticed in society that people need something extra in their daily lives and we attempt to speculate where their perceived value lies through the concept of “weekday-luxury." Our goal is to determine a deeper understanding and insight into this phenomenon and how it meets our needs through an identifiable pattern. We also analyze the nature of “weekday-luxury” and its meaning. This essay further focuses on peoples effort to “treat ourselves” from which we have chosen a market-oriented perspective, as well as a quantitative method, from which we have performed eight personal interviews and three mail interviews.</p>

<p>In system identification, different methods are often classified as parametric or non-parametric methods. For parametric methods, a parametric model of a system is considered and the model parameters are estimated. For non-parametric methods, no parametric model is used and the result of the identification is given as a curve or a function.</p><p>One of the non-parametric methods is the impulse response analysis. This approach is dynamic simulation. This thesis introduces a new paradigm for dynamic simulation, called impulse-based simulation. This approach is based on choosing a Dirac function as input, and as a result, the output will be equal to the impulse response. However, a Dirac function cannot be realized in practice, and an approximation has to be used. As a consequence, the output will deviate from the impulse response. Once the impulse response is estimated, a parametric model can be fitted to the estimation.</p><p>This thesis aims to determine the parameters in a parametric model from an estimated impulse response. The process of investigating the models is a critical aspect of the project. Correlation analysis is used to obtain the weighting function from the estimates of covariance functions.</p><p>Later, a relation formed between the parameters and the estimates (obtained by correlation analysis) in the form of a linear system of equations. Furthermore, simulations are carried out using Monte Carlo for investigating the properties of the two step approach, which involves in correlation analysis to find h-parameters and least squares and total least squares methods to solve for the parameters of the model. In order to evaluate the complete capability of the approach to the noise variation a study of signal to noise ratio and mean, mean square error and variances of the estimated parameters is carried out.</p><p>The results of the Monte Carlo study indicate that two-step approach can give rather accurate parameter estimates. In addition, the least squares and total least squares methods give similar results.</p>