Thesis (M.S. in Engineering Acoustics)--Naval Postgraduate School, December 2009. / Thesis Advisor(s): Kapolka, Daphne ; Smith, Kevin B. "December 2009." Description based on title screen as viewed on January 29, 2010. Author(s) subject terms: Particle velocity, beamforming, beam pattern, acoustic array, acoustic vector sensor, Microflown, hybrid array, frequency spectrum, linear array, directional. Includes bibliographical references (p. 151-153). Also available in print.

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<p>The notion that humans have specialized chemicals used for communication between conspecifics, so-called pheromones, has attracted much attention and discussion. This thesis demonstrates in four separate studies that a human endogenous steroidal compound that is abundant in male sweat, androstadienone, affects women in several ways that differ to that of common odors. Specifically, androstadienone was found in Study I to have unique psychophysical characteristics in that the sensitivity distribution of the odor is bimodal with a smaller subpopulation consisting of highly sensitive individuals. Trigeminal mediation of this bimodality was experimentally excluded. Moreover, Study II demonstrated that women’s cortical activation of androstadienone exposure was found to differ to that of common odorants in that androstadienone was processed faster than two perceptually similar control odors. It was further demonstrated that a non-detectable amount of androstadienone can reliably modulate both mood and physiology in women (Study III & IV); in particular mood referring to attention processes. Study IV showed that androstadienone-induced mood changes in heterosexual women were only evident when the experiment was administered by an experimenter of different sex. The combined results from these studies suggest that androstadienone serves as a human modulator pheromone that guides our behavior by inducing subtle changes in higher cognitive processes in relation to the ecological context at hand. A new definition of human pheromones is proposed and discussed in relation to the obtained results.</p>

The notion that humans have specialized chemicals used for communication between conspecifics, so-called pheromones, has attracted much attention and discussion. This thesis demonstrates in four separate studies that a human endogenous steroidal compound that is abundant in male sweat, androstadienone, affects women in several ways that differ to that of common odors. Specifically, androstadienone was found in Study I to have unique psychophysical characteristics in that the sensitivity distribution of the odor is bimodal with a smaller subpopulation consisting of highly sensitive individuals. Trigeminal mediation of this bimodality was experimentally excluded. Moreover, Study II demonstrated that women’s cortical activation of androstadienone exposure was found to differ to that of common odorants in that androstadienone was processed faster than two perceptually similar control odors. It was further demonstrated that a non-detectable amount of androstadienone can reliably modulate both mood and physiology in women (Study III &amp; IV); in particular mood referring to attention processes. Study IV showed that androstadienone-induced mood changes in heterosexual women were only evident when the experiment was administered by an experimenter of different sex. The combined results from these studies suggest that androstadienone serves as a human modulator pheromone that guides our behavior by inducing subtle changes in higher cognitive processes in relation to the ecological context at hand. A new definition of human pheromones is proposed and discussed in relation to the obtained results.

Research suggests that physical activity may play a role in preserving cognitive function in older adulthood. However, the exact nature, direction, and magnitude of observed associations remain unclear. The current study utilized a microlongitudinal design to repeatedly assess cognitive function and physical activity across five days. Two studies examined relationships between physical activity, physical fitness, and cognitive function among community-dwelling older adults. The first study examined associations between baseline performance in a measure of everyday cognition and multiple measures of physical activity and physical fitness. Bivariate analyses revealed that objectively measured physical activity of moderate-to-vigorous intensity, repeated chair stand time and 6-minute walk distance were significantly associated with everyday cognition. After adjusting for covariates in a multiple regression model, physical activity was not significantly associated with everyday cognition. However, a composite physical fitness score created from 6-minute walk distance and repeated chair stand time was significantly associated with DECA, and the full model accounted for 38% of the variance in baseline DECA performance. The second study investigated within- and between-person relationships between daily physical activity and cognitive function. Study participants wore an activity monitor and completed a battery of cognitive assessments for five days. Multilevel modeling analyses indicated that same-day total number of steps was significantly associated with better visual speed of processing but not everyday cognition, or inductive reasoning.. Time spent in moderate-to-vigorous activity was not significantly associated with same-day cognitive performance in any domain. However, previous-day moderate-to-vigorous physical activity was significantly associated with better inductive reasoning and speed of processing the following day, after controlling for age, gender and physical fitness. Time spent in moderate-to-vigorous activity explained 16% of the within-person variability in speed of processing. Physical fitness and age did not explain significant variability in between-person cognitive function. Results obtained in the present study varied according to how physical activity and cognition were operationalized and measured. Associations between physical activity and cognition were more evident with moderate-to-vigorous activity, as opposed to total activity, and an acute temporal relationship was suggested, with better cognitive performance following engagement in moderate-to-vigorous physical activity. Results also indicated that within-person fluctuations in domains of cognitive performance were positively associated with physical activity, and were more pronounced with cognitively complex tasks that were timed.

With the growing older adult population, neurodegenerative diseases common in old age such as mild cognitive impairment (MCI) or Parkinson’s disease (PD) are becoming increasingly germane areas of research. Pharmacological treatments have thus far been unsuccessful in treating cognitive decline associated with these neurodegenerative disorders. Alternative interventions, such as cognitive training programs, have shown promise. The current dissertation contains three papers examining cognitive interventions in neurodegenerative diseases. The first paper examined the longitudinal effects of cognitive speed of processing training (SPT) among those with PD. Results showed that training gains seen at initial post-test were maintained three months later. The second paper examined the effects of SPT among those with psychometrically-defined MCI and found small to medium effect sizes for improvements in everyday functional performance among those trained. The third paper examined the effects of auditory cognitive training among cognitively healthy older adults and those with psychometrically-defined MCI and found that effects may differ between those with and with MCI. Overall, these papers show that training effects can be maintained longitudinally and may potentially transfer to everyday functioning in those with neurodegenerative diseases. However, not all cognitive training programs show benefits in all areas, and individuals with differing cognitive statuses may benefit differentially from cognitive training. Future research should further explore the longitudinal effects of these training programs as well as the possibility of transfer to untrained abilities.

The cutting of foods is characterized by deformation, fracture and friction processes, and the viscoelastic properties of the cutting materials determine their rate-dependent cutting behavior. This is responsible for uncontrolled fracture and deformation events with increasing cutting velocity. There is a significant information deficit regarding the assignment of material properties and cutting parameters, as well as regarding a process description for industrial high-speed cutting. The aim of the work is the analysis of the velocity-dependent cutting behavior of foods up to the high-speed range. The focus is on the deformation and fracture phenomena, analysed by methods of classical material analysis but also associated cutting experiments performed in the range from low to high cutting velocities. For high-speed analyses, a test station enabling cutting velocities of up to 10 m/s was designed. To identify relevant material and cutting parameters and to establish a systematic experimental program, elastomer-based model systems with controllable viscoelastic profiles were developed. The results of the respective investigations were further verified for foods. The velocity-dependent deformation behavior during cutting could be described by dynamic-mechanical material analyses in the frequency range. Cutting force slopes at the beginning of the cutting process correlated with the complex moduli and were furthermore dependent on the cutting velocity; this dependency corresponded to the frequency behavior from material analysis. The fracture properties could be attributed to ductile (polymeric systems) or brittle behavior (cellular plant systems). Confectionary products had a strong temperature- and time-dependent behavior with ductile-brittle transition within the experimental conditions. The results obtained demonstrate that there is a significant relationship between viscoelasticity and velocity-dependent cutting behavior. They allow a phenomenological process description of high-speed cutting and can be used as a basis for the balancing of cutting forces and as input parameters for numerical analyses of the cutting process. / Das Schneiden von Lebensmitteln ist geprägt durch Deformations-, Bruch- und Reibvorgänge. Dabei bestimmen die viskoelastischen Eigenschaften der Schneidgüter deren geschwindigkeitsabhängiges Schneidverhalten. Dies führt mit zunehmender Schneidgeschwindigkeit zu unkontrollierten Bruch- und Deformationsereignissen. Dabei besteht ein Informationsdefizit bei der konkreten Zuweisung von Materialeigenschaften und Schneidparametern sowie einer Verfahrensbeschreibung für das industrielle Hochgeschwindigkeitsschneiden. Ziel der Arbeit ist die Analyse des geschwindigkeitsabhängigen Schneidverhaltens von Lebensmitteln bis in den Hochgeschwindigkeitsbereich. Der Fokus richtet sich auf die Untersuchung der Teilphänomene Deformation und Bruch durch Methoden der klassischen Materialanalyse sowie zugeordnete Schneidexperimente im Bereich von niedrigen bis hohen Schneidgeschwindigkeiten. Für entsprechende Hochgeschwindigkeitsanalysen wurde ein Versuchsstand mit Schneidgeschwindigkeiten von bis zu 10 m/s konzipiert. Zur Identifikation relevanter Material- und Schneidparameter und zur Aufstellung des systematischen Versuchsprogramms wurden Modellsysteme auf Elastomerbasis mit steuerbarem viskoelastischen Profil entwickelt. Die Ergebnisse wurden für Lebensmittel verifiziert. Das geschwindigkeitsabhängige Deformationsverhalten beim Schneiden konnte durch dynamisch-mechanische Materialanalysen im Frequenzbereich beschrieben werden. Dabei korrelierten Kraftanstiege zu Beginn des Schneidvorganges mit den Komplexmoduln. Die Anstiege zeigten eine Abhängigkeit von der Geschwindigkeit; diese entsprach dem Frequenzverhalten aus der Materialanalyse. Die Brucheigenschaften konnten produktspezifisch duktilem (polymere Systeme) oder sprödem Verhalten (zelluläre, pflanzliche Systeme) zugeordnet werden. Zuckerwaren zeigten ein stark temperatur - und zeitabhängiges Verhalten mit duktil-sprödem Übergang innerhalb der Versuchsbedingungen. Die gewonnenen Erkenntnisse demonstrieren den Zusammenhang von Viskoelastizität und geschwindigkeitsabhängigem Schneidverhalten. Sie erlauben eine phänomen ologische Verfahrensbeschreibung des Hochgeschwindigkeitsschneidens und können als Basis für die Bilanzierung von Schneidkräften und als Eingangsparameter für numerische Analysen des Schneidvorganges dienen.

L’augmentation de la taille des réseaux actuels ainsi que de la diversité des applications qui les utilisent font que les architectures de calcul traditionnelles deviennent limitées. En effet, les architectures purement logicielles ne permettent pas de tenir les débits en jeu, tandis que celles purement matérielles n’offrent pas assez de flexibilité pour répondre à la diversité des applications. Ainsi, l’utilisation de solutions de type matériel programmable, en particulier les Field Programmable Gate Arrays (FPGAs), a été envisagée. En effet, ces architectures sont souvent considérées comme un bon compromis entre performances et flexibilité, notamment grâce à la technique de Reconfiguration Dynamique Partielle (RDP), qui permet de modifier le comportement d’une partie du circuit pendant l’exécution. Cependant, cette technique peut présenter des inconvénients lorsqu’elle est utilisée de manière intensive, en particulier au niveau du stockage des fichiers de configuration, appelés bitstreams. Pour palier ce problème, il est possible d’utiliser la relocation de bitstreams, permettant de réduire le nombre de fichiers de configuration. Cependant cette technique est fastidieuse et exige des connaissances pointues dans les FPGAs. Un flot de conception entièrement automatisé a donc été développé dans le but de simplifier son utilisation.Pour permettre une flexibilité sur l’enchaînement des traitements effectués, une architecture de communication flexible supportant des hauts débits est également nécessaire. Ainsi, l’étude de Network-on-Chips dédiés aux circuits reconfigurables et au traitements réseaux à haut débit.Enfin, un cas d’étude a été mené pour valider notre approche. / The increase in both size and diversity of applications regarding modern networks is making traditional computing architectures limited. Indeed, purely software architectures can not sustain typical throughputs, while purely hardware ones severely lack the flexibility needed to adapt to the diversity of applications. Thus, the investigation of programmable hardware, such as Field Programmable Gate Arrays (FPGAs), has been done. These architectures are indeed usually considered as a good tradeoff between performance and flexibility, mainly thanks to the Dynamic Partial Reconfiguration (DPR), which allows to reconfigure a part of the design during run-time.However, this technique can have several drawbacks, especially regarding the storing of the configuration files, called bitstreams. To solve this issue, bitstream relocation can be deployed, which allows to decrease the number of configuration files required. However, this technique is long, error-prone, and requires specific knowledge inFPGAs. A fully automated design flow has been developped to ease the use of this technique. In order to provide flexibility regarding the sequence of treatments to be done on our architecture, a flexible and high-throughput communication structure is required. Thus, a Network-on-Chips study and characterization has been done accordingly to network processing and bitstream relocation properties. Finally, a case study has been developed in order to validate our approach.

La conduite automobile continue d'être le mode de transport dominant dans le monde et le nombre de véhicules sur la route ne devrait qu’augmenter au cours des prochaines décennies. Dans un même temps, l'évolution démographique qui se produit actuellement dans le monde industrialisé implique que la proportion de conducteurs âgés sur la route devrait augmenter considérablement. L'âge s'accompagne de changements de grande envergure dans les systèmes physiques, sensoriels et cognitifs, entraînant des changements fonctionnels qui peuvent être subtils ou profonds. Nous commençons seulement à comprendre comment la variabilité normale et pathologique de ces mesures fonctionnelles affecte les performances de conduite et la sécurité. Le développement d'un outil fiable et fondé sur des données probantes pour distinguer les conducteurs prudents des conducteurs dangereux continue d'être une préoccupation majeure pour les chercheurs en gérontologie, en accidentologie et en clinique. L'accumulation de preuves suggère maintenant qu'il existe un lien important entre des capacités cognitives spécifiques telles que la vitesse de traitement de l’information et l'attention, et les performances de conduite. Continuer à explorer cette relation pour peut-être un jour développer un tel outil est une entreprise importante. Une autre implication de la relation entre les capacités cognitives et les performances de conduite est que les interventions conçues pour les améliorer ou les maintenir pourraient éventuellement améliorer ou maintenir la sécurité et le confort de conduite des individus à court et à long terme. L'objectif de cette thèse est triple. Premièrement, il développe et valide une nouvelle méthodologie pour évaluer les performances de conduite des jeunes adultes et des adultes plus âgés à l'aide de scénarios de simulation de conduite personnalisés. Deuxièmement, elle pousse l'état de nos connaissances sur la façon dont les capacités cognitives sont liées à la performance de conduite en démontrant que la performance sur un test intégratif d'attention dynamique et de vitesse de traitement - c'est-à-dire le suivi d'objets multiples en 3D (3D-MOT) - prédit les performances des conducteurs de différents groupes d'âge. Enfin, elle offre des preuves suggérant que la formation 3D-MOT améliore réellement la fonction attentionnelle et la vitesse de traitement en transférant la performance sur un test indépendant de ces capacités et, finalement, que cette amélioration pourrait se traduire par une amélioration des performances de conduite. / Driving continues to be the world’s dominant form of transportation and the number of vehicles on the road is only projected to increase in the coming decades. At the same time, the demographic shift currently occurring in the industrialized world implies that the proportion of older adult drivers on the road is set to increase substantially. With age comes wide-ranging changes in physical, sensory and cognitive systems resulting in functional changes that can be subtle or profound. We are only beginning to understand how both normal and pathological variability in these functional measures affect driving performance and safety. Developing a reliable, evidence-based tool to distinguish safe from unsafe drivers continues to be a major preoccupation for gerontology, accidentology, and clinical researchers alike. Accumulating evidence now suggests that there is an important link between specific cognitive abilities such as speed-of-processing, attention, and driving performance. Continuing to explore this relationship in order to perhaps one day develop such a tool is an important endeavour. Another implication of the relationship between cognitive abilities and driving performance is that interventions designed to improve or sustain these might conceivably enhance or maintain individuals’ driving safety and comfort in the short- and long-term. The purpose of this thesis is threefold. First, it develops and validates a novel methodology for assessing both young adult and older adult driving performance using custom driving simulator scenarios. Second, it pushes the state of our knowledge of how cognitive abilities relate to driving performance by demonstrating that performance on an integrative test of dynamic attention and speed-of-processing—i.e., 3-dimensional multiple object tracking (3D-MOT)— predicts how drivers of different age groups perform. Finally, it offers evidence to suggest that training 3D-MOT actually enhances attentional function and speed-of-processing by transferring to performance on an unrelated test of these abilities and, ultimately, that this improvement might translate to improved driving performance.