The Oath Keepers: Patriotism, Dissent, and the Edge of Violence

This dissertation investigates a prominent group in the patriot/militia movement called the Oath Keepers. It explores how the group uses references to core political ideas and important political events from American history. It argues that these rhetorical strategies serve three purposes: (1) helping the group’s supporters to make sense of contemporary America, (2) providing the group’s supporters with models of appropriate behavior in response to ongoing events, and (3) help the group to gain additional support. It also argues that different rhetorical strategies are useful for different purposes and target different audiences

Computational fluid dynamics investigation into flow behavior and acoustic mechanisms at the trailing edge of an airfoil

Airfoil self-noise or trailing edge noise and shear noise was investigated computationally for a NACA0012 airfoil section, focusing on noise mechanisms at the trailing edge to identify and understand sources of noise production using ANSYS Fluent. A two-dimensional computational fluid dynamics simulation has been performed for 0°, 8° and 16° airfoil angle of attack capturing surface pressure contours, contours of turbulent intensity, contours of surface acoustic power level, vorticity magnitude levels across the airfoil profile, and x and y directional self and shear noise sources across the airfoil profile. The results, indicate that pressure gradients at the upper surface do increase as the angle of attack increase which is a measure of vortices near the surface of the trailing edge associated with turbulence cease as the boundary layer begins to separate. Comparison of the turbulent intensity contours with surface acoustic power level contours demonstrated direct correlation between the energy contributed by turbulent structures (i.e. vortices), and the level of noise measured at the surface, and within the boundary layer of the airfoil. As angle of attack is increased both x and y sources have the same trends, however, y sources (perpendicular to the free-stream flow) appear to have a bigger impact as angle of attack is increased. Furthermore, as the angle of attack increased, shear noise contributes less and less energy further downstream of the airfoil, and becomes dominated by noise energy from vortical structures within turbulence. The two-dimensional computational fluid dynamics simulation revealed pressure, turbulent intensity and surface acoustic power contours, that further corroborated the previously tested noise observations phenomena at the trailing edge of the airfoil

Jazz Parliament Duo

Kennesaw State University School of Music presents Jazz Parliament Duo featuring Sam Skelton, saxophones and Tyrone Jackson, piano.https://digitalcommons.kennesaw.edu/musicprograms/1413/thumbnail.jp

An investigation into flow behavior and acoustic mechanisms at the trailing edge of an airfoil

The aerodynamic and acoustic testing of a NACA0012 airfoil section was performed in an open wind tunnel, focusing on noise mechanisms at the trailing edge to identify and understand sources of noise production. The sound measurement profiles were captured by embedding microphones along the chord at various distances from the trailing edge and at different geometric angles of attack. The embedded microphones have successfully captured all noise sources due to aerodynamic flow over the NACA 0012 airfoil at the trailing edge, which included the following major peak frequencies 44 Hz, 93 Hz, 166 Hz and 332Hz. The fundamental frequency of the model tested was identified by peak frequency (166Hz). It appears that these frequencies do not deviate as the angle of attack is increased. The general trend is Strohal numbers decrease as the flow moves downstream which indicate the amount of resonance (i.e. periodic, non-random vortices) decreases further downstream, which is to be expected given the onset of turbulence. Two bands of frequencies were identified. The frequency spectra between 1 to 3kHz show a measure of far field noise energy while frequency spectra in the range 3 to 10kHz shows near field noise energy which is due to mechanisms associated with wake flow (separation)

Computation of Deterministic Volatility Surfaces

The 'volatility smile' is one of the well-known biases of Black-Scholes models for pricing options. In this paper, we introduce a robust method of reducing this bias by pricing subject to a deterministic functional volatility $\sigma = \sigma (S,t)$. This instantaneous volatility is chosen as a spline whose weights are determined by a regularised numerical strategy that approximately minimises the difference between Black-Scholes vanilla prices and known market vanilla prices over a range of strikes and maturities; these Black-Scholes prices are calculated by solving the relevant partial differential equation numerically using finite element methods. The instantaneous volatility generated from vanilla options can be used to price exotic options where the skew and term-structure of volatility are important, and we illustrate the application to barrier options

A flexible framework for assessing the quality of crowdsourced data

Ponencias, comunicaciones y pósters presentados en el 17th AGILE Conference on Geographic Information Science "Connecting a Digital Europe through Location and Place", celebrado en la Universitat Jaume I del 3 al 6 de junio de 2014.Crowdsourcing as a means of data collection has produced previously unavailable data assets and enriched existing ones, but its quality can be highly variable. This presents several challenges to potential end users that are concerned with the validation and quality assurance of the data collected. Being able to quantify the uncertainty, define and measure the different quality elements associated with crowdsourced data, and introduce means for dynamically assessing and improving it is the focus of this paper. We argue that the required quality assurance and quality control is dependent on the studied domain, the style of crowdsourcing and the goals of the study. We describe a framework for qualifying geolocated data collected from non-authoritative sources that enables assessment for specific case studies by creating a workflow supported by an ontological description of a range of choices. The top levels of this ontology describe seven pillars of quality checks and assessments that present a range of techniques to qualify, improve or reject data. Our generic operational framework allows for extension of this ontology to specific applied domains. This will facilitate quality assurance in real-time or for post-processing to validate data and produce quality metadata. It enables a system that dynamically optimises the usability value of the data captured. A case study illustrates this framework