Chris L. Pettit

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A patient with primary extranodal lymphoma arising in the trachea presented with severe upper airway obstruction. The tumor was localized at presentation. The patient has remained disease-free for 12 months following surgical resection and local radiation treatment. The tumor had distinctive morphologic features characteristic of low-grade lymphomas of(More)
Outdoor sound propagation predictions are compromised by uncertainty and error in the atmosphere and terrain representations, and sometimes also by simplified or incorrect physics. A model's predictive power, i.e., its accurate representation of the sound propagation, cannot be assessed without first quantifying the ensemble sound pressure variability and(More)
Predictive skill for outdoor sound propagation is assessed using high-resolution atmospheric fields from large-eddy simulations (LES). Propagation calculations through the full LES fields are compared to calculations through subsets of the LES fields that have been processed in typical ways, such as mean vertical profiles and instantaneous vertical profiles(More)
The optimal sensor placement problem, as considered here, is to select the types and locations of sensors providing coverage at highvalue terrain locations while minimizing a specified cost function. The cost function can reflect various disincentives, such as the actual cost of the sensors, the total number of sensors, and the probability that the sensor(More)
Toward a definition and understanding of correlation for variables constrained by random relations Fulvio Tonon a & Chris L. Pettit b a Department of Civil Engineering , University of Texas , 1 University Station C1792, Austin, TX, 78712-0280, USA b Department of Aerospace Engineering , United States Naval Academy MS-11B , 590 Holloway Road, Annapolis, MD,(More)
The Environmental Awareness for Sensor and Emitter Employment (EASEE) software is designed to help in surveillance planning by predicting detection performance of sensors and optimizing sensor selection and placement for intrusion detection around any controlled area, including power plants, dams, borders, prisons, military bases, combat outposts, etc. By(More)
Many outdoor sound propagation models exist, ranging from highly complex physics-based simulations to simplified engineering calculations, and more recently, highly flexible statistical learning methods. Several engineering and statistical learning models are evaluated by using a particular physics-based model, namely, a Crank-Nicholson parabolic equation(More)
The accuracy of outdoor sound propagation predictions is often limited by imperfect knowledge of the atmospheric and ground properties, and random environmental variations such as turbulence. This article describes the impact of such uncertainties, and how they can be efficiently addressed and quantified with stochastic sampling techniques such as Monte(More)