Navier-Stokes-alpha model: LES equations with nonlinear dispersion

We present a framework for discussing LES equations with nonlinear dispersion. In this framework, we discuss the properties of the nonlinearly dispersive Navier-Stokes-alpha model of incompressible fluid turbulence --- also called the viscous Camassa-Holm equations and the LANS equations in the literature --- in comparison with the corresponding properties of large eddy simulation (LES) equations obtained via the approximate-inverse approach. In this comparison, we identify the spatially filtered NS-alpha equations with a class of generalized LES similarity models. Applying a certain approximate inverse to this class of LES models restores the Kelvin circulation theorem for the defiltered velocity and shows that the NS-alpha model describes the dynamics of the defiltered velocity for this class of generalized LES similarity models. We also show that the subgrid scale forces in the NS-alpha model transform covariantly under Galilean transformations and under a change to a uniformly rotating reference frame. Finally, we discuss in the spectral formulation how the NS-alpha model retains the local interactions among the large scales, retains the nonlocal sweeping effects of large scales on small scales, yet attenuates the local interactions of the small scales amongst themselves.Comment: 15 pages, no figures, Special LES volume of ERCOFTAC bulletin, to appear in 200

Balloon occlusion retrograde transvenous obliteration of gastric varices in two non-cirrhotic patients with portal vein thrombosis

This report describes two non-cirrhotic patients with portal vein thrombosis who underwent successful balloon occlusion retrograde transvenous obliteration (BRTO) of gastric varices with a satisfactory response and no complications. One patient was a 35-year-old female with a history of Crohn's disease, status post-total abdominal colectomy, and portal vein and mesenteric vein thrombosis. The other patient was a 51-year-old female with necrotizing pancreatitis, portal vein thrombosis, and gastric varices. The BRTO procedure was a useful treatment for gastric varices in non-cirrhotic patients with portal vein thrombosis in the presence of a gastrorenal shunt

Piloting Multimodal Learning Analytics using Mobile Mixed Reality in Health Education

© 2019 IEEE. Mobile mixed reality has been shown to increase higher achievement and lower cognitive load within spatial disciplines. However, traditional methods of assessment restrict examiners ability to holistically assess spatial understanding. Multimodal learning analytics seeks to investigate how combinations of data types such as spatial data and traditional assessment can be combined to better understand both the learner and learning environment. This paper explores the pedagogical possibilities of a smartphone enabled mixed reality multimodal learning analytics case study for health education, focused on learning the anatomy of the heart. The context for this study is the first loop of a design based research study exploring the acquisition and retention of knowledge by piloting the proposed system with practicing health experts. Outcomes from the pilot study showed engagement and enthusiasm of the method among the experts, but also demonstrated problems to overcome in the pedagogical method before deployment with learners

Parallel asynchronous hardware implementation of image processing algorithms

Research is being carried out on hardware for a new approach to focal plane processing. The hardware involves silicon injection mode devices. These devices provide a natural basis for parallel asynchronous focal plane image preprocessing. The simplicity and novel properties of the devices would permit an independent analog processing channel to be dedicated to every pixel. A laminar architecture built from arrays of the devices would form a two-dimensional (2-D) array processor with a 2-D array of inputs located directly behind a focal plane detector array. A 2-D image data stream would propagate in neuron-like asynchronous pulse-coded form through the laminar processor. No multiplexing, digitization, or serial processing would occur in the preprocessing state. High performance is expected, based on pulse coding of input currents down to one picoampere with noise referred to input of about 10 femtoamperes. Linear pulse coding has been observed for input currents ranging up to seven orders of magnitude. Low power requirements suggest utility in space and in conjunction with very large arrays. Very low dark current and multispectral capability are possible because of hardware compatibility with the cryogenic environment of high performance detector arrays. The aforementioned hardware development effort is aimed at systems which would integrate image acquisition and image processing

Ground Support for the Space-Based Range Flight Demonstration 2

The primary objective of the NASA Space-Based Range Demonstration and Certification program was to develop and demonstrate space-based range capabilities. The Flight Demonstration 2 flights at NASA Dryden Flight Research Center were conducted to support Range Safety (commanding and position reporting) and high-rate (5 Mbps) Range User (video and data) requirements. Required ground support infrastructure included a flight termination system computer, the ground-data distribution network to send range safety commands and receive range safety and range user telemetry data and video, and the ground processing systems at the Dryden Mission Control Center to process range safety and range user telemetry data and video

Dark with Excessive Bright: Gambling Tells and the Naming Taboo

Within sacred language the belief has existed that the personal name is an intrinsic part of oneself. As such, its revelation threatens exposure to powers that might undo its bearer. Smith considers the relation between the detection of tells in gambling and that of so-called true names. Strategies of concealment and detection that are basic to both tell-reading and true-naming are explored in relation to post-colonial theory\u27s insights into using light in order to hide things

A place for locative media: A theoretical framework for assessing locative media use in urban environments

By 2050, three quarters of the world’s population will live in large urban conurbations. Within these environments, we see the rise of locative media – mobile technologies that capture and deliver location- and time-specific content and connections to their users. The key attribute of locative media that distinguishes them from other mobile media is location. Yet ideas of how locative media influence our relationship to the spaces we inhabit remain undertheorized. This gap arises because of an absence of interrogation into how and why people come to develop a connection with these spaces – how and why a space becomes a place to which its inhabitants ascribe meaning and in which social relations occur among them. This thesis proposes a theoretical framework for interrogating locative media in the context of everyday, embodied and mobile urban place-making, to better analyze the opportunities and challenges afforded through locative media

Politics, infrastructure and non-human subjects: The Inka occupation of the Amaybamba cloud forests

This dissertation presents the results of an archaeological study of the Inka occupation and transformation of the Amaybamba Valley, Peru, during the Late Horizon, just prior to the Spanish Conquest. This region lies among the dense cloud forests of the eastern Andes, and was situated at the northwestern edges of the Inka heartland centered around the former imperial capital of Cuzco. The main interest for the Inkas in the Amaybamba lay in its capacity to produce large amounts of coca, a plant which was the foundation of a great many exchange relationships across the Andes. Not only was it central to exchanges between humans, but also with the most important non-human powers of the Inka world. These powers included major landscape entities, such as the mountains (apukuna) and other kinds of earth beings (often in the form of rock outcrops, or lakes, known as wak'as). The main focus of this dissertation is the question of how these entities were made subjects of the Inka polity. The broader theoretical framework that underpins my thesis is what I refer to as `political ontology', from which I argue for taking a `step-back' from more traditional (post-Enlightenment) accounts of politics which assume the state is a set of relationships between human actors only, and thereby consider the possibility of non-modern states in which other-than-human beings could be made into political subjects. The Amaybamba is thus presented as a case-study through which we can examine the empirical, archaeological traces of just such processes of subjectification. The Inka presence in the Amaybamba mainly took the form of a series of royal landholdings, which were associated with a number of aristocratic lineages within the empire. My arguments therefore have broader implications for how we understand the royal estate system more generally. In particular, I suggest that the royal estates - which appear from our Western perspective to resemble a series of elite-owned plantations - were in Inka eyes seen more as a means to discipline and control the productive capacities of a potent community of non-humans