Publications by authors named "Michael David Johnson"

The recovery of the properties or geometry of a rough surface from scattered sound is of interest in many applications, including medicine, water engineering, or structural health monitoring. Existing approaches to reconstruct the roughness profile of a scattering surface based on wave scattering have no intrinsic way of predicting the uncertainty of the reconstruction. In an attempt to recover this uncertainty, a Bayesian framework, and more explicitly, an adaptive Metropolis scheme, is used to infer the properties of a rough surface, parameterised as a superposition of sinusoidal components.

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Recent studies have demonstrated that acoustic waves can be used to reconstruct the roughness profile of a rigid scattering surface. In particular, the use of multiple microphones placed above a rough surface as well as an analytical model based on the linearised Kirchhoff integral equations provides a sufficient base for the inversion algorithm to estimate surface geometrical properties. Prone to fail in the presence of high noise and measurement uncertainties, the analytical approach may not always be suitable in analysing measured scattered acoustic pressure.

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Background: The lateral extensile approach (LEA) is an operative approach for calcaneal fractures. High rates of wound complications have led to alternative approaches such as the sinus tarsi approach to grow in popularity. The LEA affords substantial visualization of the calcaneus.

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Prague, the Czech Republic, is a popular sex tourism destination where sex work is decriminalized and young men offer sexual services at low prices relative to countries in Western Europe. This quantitative survey aimed to identify some of the demographic characteristics of these young men and their experiences in the sex industry. Internet escorts (N = 20) and sex workers in bars and clubs (N = 20) completed the survey anonymously in spring 2011.

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Introduction: Management and outcomes for duodenal adenomas may vary based on etiology, familial versus sporadic. We reviewed the records of patients managed at our institution for duodenal adenomatous polyps for the 20-year period ending July 2006.

Discussion: Methods of polyp resection (endoscopic, local surgical resection, or definitive surgical resection) within both sporadic and familial patient groups were compared.

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