In the global framework of improving vibro-acoustic numerical prediction quality together with the need to decrease the number of prototyping stages, this manuscript focuses on achieving greater accuracy for acoustic numerical simulations by making use of a parametric updating technique, which enables tuning the model parameters inside physically meaningful boundaries. The improved model is used for the next prototyping stages, allowing more accurate results within reduced simulation times. The updating technique is based on recent works dealing with the constitutive relation error method (CRE) applied to acoustics. The updating process focuses on improving the acoustic damping matrix related to the absorbing properties of the materials covering the borders of the acoustic domain.

The malleable nature of human memory has been the focus of considerable research in recent years. Memory is no longer viewed as permanent and non-modifiable. When a consolidated memory is reactivated it becomes labile and modifiable again. Recently, updating of reactivated memory has been demonstrated, manifesting as the addition of new but relevant information. New, similar, information that is acquired in a separate learning episode is embedded within the original memory. We were interested in exploring the effects of psychosocial stress on this episodic memory updating. Individuals were stressed prior to reactivation of the original memory (Experiment 1) or prior to the onset of reconsolidation of the original memory (Experiment 2). Based on prior research, we hypothesized that in both experiments stress would impair memory updating. In Experiment 1, stress reduced memory updating, but this effect did not achieve statistical significance. In Experiment 2, stress impaired the consolidation of an `updated' memory. These findings not only corroborate stress-induced impairments of memory but also shed light on the possible consequences of impaired memory updating. We discuss the relevance of these experimental results in the context of problem solving.

The nature and assessment of executive function are areas of active research. Many current assessments of executive function are complex, have limited reliability and validity, and suffer from task impurity, meaning other cognitive processes may indirectly influence task performance. Additionally, measures may be culture, language, or education bound limiting their use in certain populations (Miyake, Emerson, & Friedman, 2000; Miyake, Friedman, et al., 2000; Strauss, Sherman, & Spreen, 2006; Stuss, 2007). The purpose of this project was to develop a novel set of executive function measures to address issues with current clinical measures. The new measures 1) can be used in an ERP environment, 2) use the same stimulus set to address task impurity and 3) use simpler cognitive operations of inhibition, set-shifting, and updating, identified in previous research by Miyake et al., (2000). Twenty-nine undergraduate participants at the University of South Florida were administered currently used clinical measures of executive function theorized to engage in inhibition, set-shifting, and updating and the set of the novel tasks. ERP data was collected during the administration of the novel tasks. Behaviorally, conditions theorized to engage executive function resulted in slower response reaction time than control conditions. Additionally, behavioral results indicated that performance on novel tasks were differentially related to different clinical EF tasks. ERP differences were observed between both Go/No-Go conditions (inhibition) and among N-back conditions (updating). Results suggest the novel executive function tasks are tapping into different cognitive processes and may be a viable tool for studying executive function in the future.

Thesis (M.S. in Operations Research)--Naval Postgraduate School, December 2009. / Thesis Advisor: Kress, Moshe. Second Reader: Johnson, Rachel. "December 2009." Description based on title screen as viewed on February 1, 2010. Author(s) subject terms: Bayesian updating model, Atmospheric Threat and Dispersion model, estimation of location and time of a chemical attack, sensor placement. Includes bibliographical references (p. 99). Also available in print.

[pt] A continuidade de operação das linhas de transmissão em Extra Alta Tensão é fundamental para o sistema de potência envolvido, especialmente em sistemas similares ao do Brasil. Torna-se então importante, realizaremos manutenção nas cadeias de isoladores com a linha energizada. A segurança do homem para a execução de serviços em linhas energizadas é definida através de distâncias que são influenciadas pela geometria da torre, por parâmetros meteorológicos e pela sobretensão que possa ocorrer no sistema. Para essa análise um método estatístico foi desenvolvido e implementado em um computador digital, a fim de se determinar o risco de falha do isolamento de uma torre frente a surtos de manobra. Como conclusão são recomendados procedimentos de cálculos para determinação das distâncias mínimas para Trabalhos em Linha Viva. / [en] The continuity of power supply in Extra-High Voltage transmission lines is one of major requirements to be achieved in electrical power systems specially in countries like Brazil. Therefore, it is of capital importance to perform maintenance work on insulator strings with energised line. The safety of personnel working o energise lines depends on the observance of clearances which are affected by geometrical characteristics of the tower, by meteorological parameters and by eventual occurrence of system overvoltages. To this purpose, a statistical method was developed and solved on a digital computer, in order to evaluate the probability of insulation failure in a tower under switching surges. On the basis of this analysis, minimum safety clearances are recommended for carrying out Live Line Works.

Prior research shows that a contextual reminder can return a previously consolidated memory to an unstable state similar to initial encoding. New knowledge presented before the trace is reconsolidated can emerge as updating of the first experience with knowledge from the second. Sleep has been implicated in the long-term strengthening and storage of newly acquired episodic memories; thus, the delay-dependent emergence of intrusions may be facilitated by a delay containing sleep. The experiments described here explore this possibility by tracking sleep while participants undergo an episodic reconsolidation paradigm, which involves learning two sets of information and a recall task, all separated by 48 hours. Prior work using this paradigm shows that reminding participants of the first learning experience prior to learning the second renders them more likely to intrude information from the second set in their recall of the first. In the present study, Experiment 1 compares amount of sleep across days in order to tease apart the differential effects on consolidation of the original Set 1 memory and its reconsolidation when it is updated with Set 2. In Experiment 2, the first analysis (Analysis A) identifies events in the sleep EEG, such as spindles, that are associated with certain elements of memory consolidation, and expands on the parameters in which they occur in memory reconsolidation in Analysis B. The overall aim of this project is to use sleep as a means to inform the nature of memory reconsolidation, which paints memory as ever changeable.

Near-infrared spectroscopy has proven to be one of the most promising techniques for the development of a noninvasive blood glucose monitoring system for diabetic patients. In this work, Fourier transform infrared (FT-IR) transmission measurements of the combination band region (4000 - 5000 cm-1) were analyzed for samples containing glucose (analyte) in a matrix of bovine serum albumin and triacetin (models for proteins and fats), all spanning physiological levels relevant for a diabetic patient. The first part of the study investigated the required spectral point-spacing for accurate detection of glucose. This was studied by systematically truncating interferograms before Fourier transforming them to single-beam spectra. A set of training data (70 samples) was collected for multivariate calibration using partial least-squares (PLS) and an external prediction set was used to verify the success of modeling glucose quantitatively. It was found that a relatively large point-spacing (16 cm-1) was successful for prediction of glucose, meaning that a shorter interferogram could be collected. The second part of the study involved collecting interferograms such that the spectral resolution was 16 cm-1, and investigating methods to extend the usefulness of calibration models for long-term data collection. Near-infrared spectroscopy often suffers from weak signals that are overwhelmed by significant instrumental drift, meaning that calibration models tend to be unsuccessful for data collected several days or months outside the calibration. For updating the calibration models, a set of 50 backgrounds containing only matrix constituents without analyte was collected on each analysis day, and used to update the original calibration model so that instrumental drift features were incorporated into the model. Background updating was found to be successful in single-beam format, producing a background-augmented (BA) PLS model that significantly improved single-beam data analysis. The standard error of prediction using the original model (PLS) and the updated model (BA-PLS) were 13.4 and 0.79 mM glucose, respectively, for a prediction set taken 176 days outside of the calibration. The matrix data also allowed for studies in background selection methods for absorbance computations as well as adaptive digital filtering that was guided by the background data.

On August 15, 2007, Pisco, Peru was hit by an earthquake of Magnitude (Mw) = 8.0 which triggered multiple liquefaction induced lateral spreads. The subduction earthquake lasted for approximately 100 seconds and showed a complex rupture. From the geotechnical perspective, the Pisco earthquake was significant for the amount of soil liquefaction observed. A massive liquefaction induced seaward displacement of a marine terrace was observed in the Canchamana complex. Later analysis using the pre- and post-earthquake images showed that the lateral displacements were concentrated only on some regions. Despite the lateral homogeneity of the marine terrace, some cross-sections showed large displacements while others had minimal displacements. The detailed documentation of this case-history makes it an ideal case-study for the determination of the undrained strength of the liquefied soils; hence, the main objective of this research is to use the extensive data from the Canchamana Slide to estimate the shear strength of the liquefied soils. In engineering practice, the undrained strength of liquefied soil is typically estimated by correlating SPT-N values to: 1) absolute value of residual strength, or 2) residual strength ratio. Our research aims to contribute an important data point that will add to the current understanding of the residual strength of liquefied soils. / Master of Science

No description available.

This thesis suggests a formulation for updating physically meaningful parameters in analytical finite element(FE) models using scanning laser Doppler vibrometer(SLDV) dynamic response data. The update formulation is demonstrated in several computer simulations. The formulation is the result of incorporating an analytical FE model into an experimental model. The experimental model efficiently utilizes SLDV data to fully exploit the instrument's capability to automatically make measurements at many locations. The data in the experimental model is posed in a manner consistent with an analytical FE model's representation for harmonic response, simplifying comparison between the two. The experimental model, which uses finite element shape functions as a basis for a least squares fit to the data, can be solved to give a velocity field based only on that data. The function resulting from inserting the analytical model into the experimental model is an expression of the prediction error of the FE model as compared to the test data. This function is minimized using a quasi-Newton optimization routine, reducing the error and resulting in an updated model. Computer simulations of the update algorithm indicate that: 1. Analytically supplied derivatives and variable scaling are required by the optimization routine to consistently converge, 2. The percentage error of updated parameters falls within two standard deviations of the data's percentage error, 3. Error in the position of the laser results in the update algorithm's failure, and, 4. Error in the parameters not included in the update will appear as error in the updated parameters' solution. / Master of Science