Weak Neutral Current Studies with Positrons

Weak neutral current interactions with charged leptons have offered unique opportunities to study novel aspects of hadronic structure and search for physics beyond the standard model. These studies in the medium energy community have been primarily through parity-violating processes with electron beams, but with the possibility of polarized positron beams, new and complementary observables can be considered in experiments analogous to their electron counterparts. Such studies include elastic proton, deep inelastic, and electron target scattering. Potential positron neutral current experiments along with their potential physics reach, requirements, and feasibility are presented

Random cliques in random graphs

We show that for each $r\ge 4$, in a density range extending up to, and slightly beyond, the threshold for a $K_r$-factor, the copies of $K_r$ in the random graph $G(n,p)$ are randomly distributed, in the (one-sided) sense that the hypergraph that they form contains a copy of a binomial random hypergraph with almost exactly the right density. Thus, an asymptotically sharp bound for the threshold in Shamir's hypergraph matching problem -- recently announced by Jeff Kahn -- implies a corresponding bound for the threshold for $G(n,p)$ to contain a $K_r$-factor. We also prove a slightly weaker result for $r=3$, and (weaker) generalizations replacing $K_r$ by certain other graphs $F$. As an application of the latter we find, up to a log factor, the threshold for $G(n,p)$ to contain an $F$-factor when $F$ is $1$-balanced but not strictly $1$-balanced.Comment: 19 pages; expanded introduction and Section 5, plus minor correction

92nd Commencement Senior Class Speaker\u27s Address

Riordan Frost offers advice and the quotes of others for his classmates to consider. He states he has argued for moral relativism in a classroom, but believes that there is goodness in the world, and that it cannot be suppressed. He advises his classmates to always give back to their community. The best cities are founded on a sense of civic responsibility, from ancient times to today

Performance in the Wartime Archive: Michio Ito at the Alien Enemy Hearing Board

Several days after the bombing of Pearl Harbor, the Japanese dancer and choreographer Michio Ito was apprehended by the United States government.  In the documents establishing his indefinite detention, the Alien Enemy Hearing Board found Ito to be “an artist of artistic temperament, striking appearance, fine manners, cultured, educated and capable of any and all sorts of propaganda, espionage and sabotage.”  In this essay I interrogate this sentence’s grammatical choreography, the “and” that links art, culture, and education to propaganda, espionage, and sabotage. The story of Ito’s remarkable career has surfaced frequently in the fields of transnational modernism, dance and performance studies, and Asian American criticism, but the period of his incarceration has yet to be addressed.  By examining the archival traces of his hearing, I show how the same “artistic temperament” that allows Ito to collaborate with W. B. Yeats and Martha Graham and to dance for heads of state leads to his incarceration as a threat to American national security.  My purpose in restaging Ito’s makeshift trial is not to exonerate him but to examine the shared hermeneutics of law and art, to indicate how swiftly a performance of otherness in the American context can shift from exotic and interesting to dangerous and in need of discipline

Managing the interdisciplinary requirements of 3D geological models.

Despite increasing computer power, the requirement to upscale 3D geological models for dynamic reservoir simulation purposes is likely to remain in many commercial environments. This study established that there is a relationship between sandbody size, cell size and changes to predictions of reservoir production as grids are upscaled. The concept of a cell width to sandbody width ratio (CSWR) was developed to allow the comparison of changes in reservoir performance as grids are upscaled. A case study of the Flounder Field in the Gippsland Basin resulted in the interpretation of three depositional environments in the intra-Latrobe reservoir interval. The sandbody dimensions associated with these depositional environments were used to build a series of 3D geological models. These were upscaled vertically and horizontally to numerous grid cell sizes. Results from over 1400 dynamic models indicate that if the CSWR is kept below 0.3 there will be a strong correlation between the average production from the upscaled grids compared to those of a much finer grid, and there will be less than 10% variation in average total field production. If the CSWR is between 0.3 and 1, there could be up to 30% difference, and once the CSWR exceeds 1.0 there is only a weak relationship between the results from upscaled grids and those of finer grids. As grids are upscaled the morphology of bodies in facies models changes, the distribution of petrophysical properties is attenuated and the structure is smoothed. All these factors result in a simplification of the fluid flow pathways through a model. Significant loss of morphology occurs when cells are upscaled to more than a half the width of the reservoir body being modelled. A simple rule of thumb is established — if the geological features of a model cannot be recognised when looking at a layer in the upscaled grid, the properties of the upscaled grid are unlikely to be similar to those of the original grid and the predictions of dynamic models may vary significantly from those of a finer grid. This understanding of the influence of sandbody size on the behaviour of upscaled dynamic models can be used in the planning stages of a reservoir modelling project. Two simple charts have been created. The first chart is for calculating the approximate number of cells in a model before it is built. The second chart is for comparing the proposed cell size against the CWSR, so that the predicted discrepancy between the ultimate production from the upscaled grid and one with much smaller cells can be assessed. These two charts enhance discussion between all interested disciplines regarding the potential dimensions of both static and upscaled dynamic models during the planning stage of a modelling project, and how that may influence the results of dynamic modelling.Thesis (Ph.D.) - University of Adelaide, Australian School of Petroleum, 200

Accuracy, independence, and impartiality: how legacy media and digital natives approach standards in the digital age

In the digital age, one of the most complex challenges for media outlets is how to re-shape the editorial responsibilities of journalism itself. Which journalistic standards, many devised last century, still fit in this new age? And which standards form the basis of a new type of journalism being pioneered by hybrid news sites that have come of age in the digital era? Kellie Riordan, a one-term journalist fellow from the ABC in Australia, has written a path-breaking and comprehensive paper which tackles these questions head on.  In it she focuses on the three key editorial standards of accuracy, independence, and impartiality,  and examines how these three principles are approached in the digital era. The paper focuses specifically on three legacy organisations (the Guardian, the New York Times, and the BBC) and three digital outlets (Quartz, BuzzFeed, and Vice News). Based on interviews with a wide range of industry experts, scholars and representatives of traditional and new media, Kellie asks two key questions: what can legacy organisations with hundreds of years of history learn from digital natives?  And which traditional journalistic standards held by legacy organisations should be more firmly adopted by newcomers? Amongst Kellie’s many conclusions is her observation that a third form of journalism is emerging; one that combines the best of legacy standards and the new approaches of digital natives. Such a hybrid form, she argues, requires a more streamlined set of editorial standards that fit the internet era