Distributed shared memory for virtual environments

Bibliography: leaves 71-77.This work investigated making virtual environments easier to program, by designing a suitable distributed shared memory system. To be usable, the system must keep latency to a minimum, as virtual environments are very sensitive to it. The resulting design is push-based and non-consistent. Another requirement is that the system should be scaleable, over large distances and over large numbers of participants. The latter is hard to achieve with current network protocols, and a proposal was made for a more scaleable multicast addressing system than is used in the Internet protocol. Two sample virtual environments were developed to test the ease-of-use of the system. This showed that the basic concept is sound, but that more support is needed. The next step should be to extend the language and add compiler support, which will enhance ease-of-use and allow numerous optimisations. This can be improved further by providing system-supported containers

Isomorphic Trends in State NIL Laws

On July 1, 2021, the NCAA released their interim NIL policies, reversing its stance from prohibiting college athletes from being compensated for their name, image, or likeness to permitting college athletes to acquire compensation in return for the use of their NIL by third parties unrelated to the athlete’s institution. As such, state NIL laws, which have only existed since 2019, have become the primary measure on what is or is not permissible in relation to NIL. State NIL laws have already evolved repeatedly since their creation, thus causing confusion on what the state NIL laws permit and prohibit. These evolutions have been guided by isomorphism, or a trend towards sameness, due to both uncertainty in the NIL environment, as well as the desire for institutions to remain competitive in offering NIL opportunities and recruiting prospective athletes. State NIL laws feature many consistent themes, such as provisions primarily targeting college athletes or institutions, provisions protecting college athlete’s ability to acquire representation for NIL activities, and provisions requiring the implementation of NIL related programming. Amendments to state NIL laws are a major source of competitive developments in the NIL environment, either eliminating provisions that restrict institution’s and college athlete’s use of NIL, or adding provisions that provide a competitive advantage for institutions wishing to aid or support their college athletes in acquiring NIL deals

Nietzsche and 'aspect-blindness'

In this thesis, I draw on Wittgensteinian philosophical thought to critically explore Nietzsche’s diagnosis of (and proposed therapy for) the alleged malaise in modernity. In chapter 1, I argue that Wittgenstein’s concepts of aspect-seeing and certainty provide the resources to resolve several apparently contradictory claims Nietzsche makes about the predicament of his fellow moderns. I show that the condition Wittgenstein calls ‘aspect-blindness’ offers a unified account of the predicament Nietzsche describes. In chapter 2, I explore Nietzsche’s claim that some overarching framework (what Wittgenstein calls a ‘form of life’) has ‘died’. I argue that the pathological attitude of Wittgenstein’s interlocutor towards frameworks provides the most satisfactory model for understanding the nature of the supposed ‘death’ of frameworks in modernity. In chapter 3, I argue that Nietzsche’s proposed remedy for the malaise of modernity is a form of therapy akin to Wittgenstein’s attempt to free his readers from a picture which holds them captive. I show that our understanding of Nietzsche’s therapeutic method will be improved if we bear in mind certain distinctions and ambiguities highlighted by Wittgensteinian discussion of pictures. In chapter 4, I address the concern that Nietzsche appears to characterise modernity in two contradictory ways as both excessively and insufficiently emotional and excessively and insufficiently sceptical. I resolve the appearance of contradiction by showing that (on Nietzsche’s view) the moderns are inherently prone to extreme shifts between poles and that many of the apparent emotions and ideals of the moderns are ‘fake’

Preconditioning for the Navier-Stokes equations with finite-rate chemistry

The extension of Van Leer's preconditioning procedure to generalized finite-rate chemistry is discussed. Application to viscous flow is begun with the proper preconditioning matrix for the one-dimensional Navier-Stokes equations. Eigenvalue stiffness is resolved and convergence-rate acceleration is demonstrated over the entire Mach-number range from nearly stagnant flow to hypersonic. Specific benefits are realized at the low and transonic flow speeds typical of complete propulsion-system simulations. The extended preconditioning matrix necessarily accounts for both thermal and chemical nonequilibrium. Numerical analysis reveals the possible theoretical improvements from using a preconditioner for all Mach number regimes. Numerical results confirm the expectations from the numerical analysis. Representative test cases include flows with previously troublesome embedded high-condition-number areas. Van Leer, Lee, and Roe recently developed an optimal, analytic preconditioning technique to reduce eigenvalue stiffness over the full Mach-number range. By multiplying the flux-balance residual with the preconditioning matrix, the acoustic wave speeds are scaled so that all waves propagate at the same rate, an essential property to eliminate inherent eigenvalue stiffness. This session discusses a synthesis of the thermochemical nonequilibrium flux-splitting developed by Grossman and Cinnella and the characteristic wave preconditioning of Van Leer into a powerful tool for implicitly solving two and three-dimensional flows with generalized finite-rate chemistry. For finite-rate chemistry, the state vector of unknowns is variable in length. Therefore, the preconditioning matrix extended to generalized finite-rate chemistry must accommodate a flexible system of moving waves. Fortunately, no new kind of wave appears in the system. The only existing waves are entropy and vorticity waves, which move with the fluid, and acoustic waves, which propagate in Mach number dependent directions. The nonequilibrium vibrational energies and species densities in the unknown state vector act strictly as convective waves. The essential concept for extending the preconditioning to generalized chemistry models is determining the differential variables which symmetrize the flux Jacobians. The extension is then straight-forward. This algorithm research effort will be released in a future version of the production level computational code coined the General Aerodynamic Simulation Program (GASP), developed by Walters, Slack, and McGrory

Dysregulation of cadherins in the intercalated disc of the spontaneously hypertensive stroke-prone rat

The structural integrity of cardiac cells is maintained by the Ca2+-dependent homophilic cell-cell adhesion of cadherins. N-cadherin is responsible for this adhesion under normal physiological conditions. The role of cadherins in adverse cardiac pathology is less clear. We studied the hearts of the stroke-prone spontaneously hypertensive (SHRSP) rat as a genetic model of cardiac hypertrophy and compared them to Wistar-Kyoto control animals. Western blotting of protein homogenates from 12-week old SHRSP animals indicated that similar levels of [beta], [gamma]-, and [alpha]-catenin and T, N and R-cadherin were expressed in the control and SHRSP animals. However, dramatically higher levels of E-cadherin were detected in SHRSP animals compared to controls at 6, 12 and 18áweeks of age. This was confirmed by quantitative Taqman PCR and immunohistochemistry. E-cadherin was located at the intercalated disc of the myocytes in co-localisation with connexin 43. Adenoviral overexpression of E-cadherin in rat H9c2 cells and primary rabbit myocytes resulted in a significant reduction in myocyte cell diameter and breadth. E-cadherin overexpression resulted in re-localisation of [beta]-catenin to the cell surface particularly to cell-cell junctions. Subsequent immunohistochemistry of the hearts of WKY and SHRSP animals also revealed increased levels of [beta]-catenin in the intercalated disc in the SHRSP compared to WKY. Therefore, remodelling of the intercalated disc in the hearts of SHRSP animals may contribute to the altered function observed in these animal