Structural-acoustic coupling and psychophysical effects in the active control of noise in vehicles

Active noise control systems offer a potential method of reducing the weight of passive acoustic treatment and, therefore, increasing vehicles' fuel efficiency. These can be particularly cost-efficient if integrated with the entertainment system. A combined system is presented employing feedforward control of engine noise and feedback control of road noise, using a `modal' error signal. Due to the dependence of the feedback system on the modal response of the vehicle cabin, the influence of structural-acoustic coupling on this response and the consequent effects on the control performance are investigated. Simulations of the performance of the control systems in rigid and non-rigid enclosures show that the feedforward component is largely unaffected by structural-acoustic coupling, whilst the modal feedback performance is reduced by 3 dB due to the shift in the frequency of the targeted acoustic mode. The simulation results are confirmed through experiments conducted in a structural-acoustic coupled enclosure

ACUE - Effective Teaching Practices: Module(s) Reflections

This is a collection of ACUE (Association of Colleges and University Educators) reflection assignments on implementing concepts from the program. The Teaching Resource Center partnered with ACUE and the corresponding modules were offered to a set of accepted instructors at CSUSB. These assignments focused on teaching practices designed to enhance the learning experience for both on-ground and online instruction. CSUSB - JHBC Full-time Lecturer, Stephen Abbott, completed the ACUE Effective College Instruction certification program from January 2019 thru June 2019. The attached assignments include reflections from a selection of completed modules

Diamagnetic Stabilization of Double-tearing Modes in MHD Simulations

Double-tearing modes have been proposed as a driver of ‘off-axis sawtooth’ crashes in reverse magnetic shear tokamak configurations. The DTM consists of two nearby rational surfaces of equal safety factor that couple to produce a reconnecting mode weakly dependent on resistivity and capable of nonlinearly disrupting the annular current. In this dissertation we examine the linear and nonlinear growth of the DTM using the extended magnetohydrodynamic simulation code MRC-3d. We consider the efficacy of equilibrium diamagnetic drifts, which emerge in the presence of a pressure gradient when ion inertial physics is included, as a means of stabilizing DTM activity. In linear slab simulations we find that a differential diamagnetic drift at the two resonant surfaces is able to both interfere with the inter-surface coupling and suppress the reconnection process internal to the tearing layers. Applying these results to a m=2, n=1 DTM in cylindrical geometry, we find that asymmetries between the resonant layers and the presence of an ideal MHD mode result in stabilization being highly dependent on the location of the pressure gradient. We achieve a significant reduction in the linear DTM growth rate by locating a strong diamagnetic drift at the outer resonant surface. In nonlinear simulations we show that growth of the magnetic islands may enhance the pressure gradient near the DTM current sheets and significantly delay disruption. Only by locating a strong drift near the outer, dominant resonant surface are we able to saturate the mode and preserve the annular current ring, suggesting that the appearance of DTM activity in advanced tokamaks may depend on the details of the plasma pressure profile

Energy transfer between surface plasmon polariton modes with hybrid photorefractive liquid crystal cells

In this thesis, a hybrid photorefractive liquid crystal cell structure with the addition of a thin 40nm Gold layer is proposed that demonstrates significant photorefractive control of Surface Plasmon Polaritons (SPP). The photorefractive effects are generated through optically controlling the conductivity of a ~100nm photoconducting poly-N-vinyl-carboxyl (PVK) layer. Therefore, when a potential is applied across the cell, the liquid crystal alignment and the SPP wavevector is able to be controlled with light. The aim for developing this device is for the eventual demonstration of SPP gain to offset the high optical losses and increase the characteristically short propagation length of SPP. The mechanism we intend to use to demonstrate gain is analogous to the asymmetric energy transfer in a wave mixing system for two laser beams used to typically characterise photorefractive materials.We first characterise the electrical and optical behaviour of the novel photorefractive plasmonic structure proposed with uniform illumination. Our system demonstrates a good photorefractive wavevector shift of 0.207µm-1 for a 1.24eV SPP; this shift is in excess of the FWHM of the SPP resonance in the attenuated total reflection spectrum (0.154µm-1). However, the electric behaviour of the system is found to be highly complex and cannot be fully characterised by an equivalent electrical circuit. In addition, due to electronic stability issues, we require a slow AC potential to demonstrate consistent photorefractive effects.In a step towards realising SPP gain, we then consider the SPP interaction with a refractive index grating written into the liquid crystal layer with the interference pattern of crossed laser beams. We find that a SPP is diffracted into additional SPP modes. Our investigation then determines the ideal parameters that maximise the energy transfer by examining the diffraction efficiency dependence of each variable of the system. The maximum energy transfer observed is 25.3±2.3% for a 1.05eV SPP from a 4µm grating. With the assistance of a numerical simulation of our system we present a series of qualitative and semi-analytical descriptions to describe the mechanisms behind the observed trends. We discover that the diffraction efficiency is dependent of three important effects; the orientation of the grating, the penetration depth of the SPP into the liquid crystal and the magnitude of the periodic electric field in the liquid crystal. In addition, to fully describe the quantitative values observed we must also consider the presence of a thin 100nm region of the liquid crystal near the photoconductor interface that does not strongly respond to the applied electric field due to anchoring forces

Can the US Minimum Data Set Be Used for Predicting Admissions to Acute Care Facilities?

This paper is intended to give an overview of Knowledge Discovery in Large Datasets (KDD) and data mining applications in healthcare particularly as related to the Minimum Data Set, a resident assessment tool which is used in US long-term care facilities. The US Health Care Finance Administration, which mandates the use of this tool, has accumulated massive warehouses of MDS data. The pressure in healthcare to increase efficiency and effectiveness while improving patient outcomes requires that we find new ways to harness these vast resources. The intent of this preliminary study design paper is to discuss the development of an approach which utilizes the MDS, in conjunction with KDD and classification algorithms, in an attempt to predict admission from a long-term care facility to an acute care facility. The use of acute care services by long term care residents is a negative outcome, potentially avoidable, and expensive. The value of the MDS warehouse can be realized by the use of the stored data in ways that can improve patient outcomes and avoid the use of expensive acute care services. This study, when completed, will test whether the MDS warehouse can be used to describe patient outcomes and possibly be of predictive value

Can the US Minimum Data Set Be Used for Predicting Admissions to Acute Care Facilities?

This paper is intended to give an overview of Knowledge Discovery in Large Datasets (KDD) and data mining applications in healthcare particularly as related to the Minimum Data Set, a resident assessment tool which is used in US long-term care facilities. The US Health Care Finance Administration, which mandates the use of this tool, has accumulated massive warehouses of MDS data. The pressure in healthcare to increase efficiency and effectiveness while improving patient outcomes requires that we find new ways to harness these vast resources. The intent of this preliminary study design paper is to discuss the development of an approach which utilizes the MDS, in conjunction with KDD and classification algorithms, in an attempt to predict admission from a long-term care facility to an acute care facility. The use of acute care services by long term care residents is a negative outcome, potentially avoidable, and expensive. The value of the MDS warehouse can be realized by the use of the stored data in ways that can improve patient outcomes and avoid the use of expensive acute care services. This study, when completed, will test whether the MDS warehouse can be used to describe patient outcomes and possibly be of predictive value

The First Regiment New Hampshire Volunteers in the Great Rebellion: containing the story of the campaign; an account of the Great uprising of the people of state, and other articles upon subjects associated with the early war period

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