An LU implicity scheme for high speed inlet analysis

A numerical method is developed to analyze the inviscid flowfield of a high speed inlet by the solution of the Euler equations. The lower-upper implicit scheme in conjunction with adaptive dissipation proves to be an efficient and robust nonoscillatory shock capturing technique for high Mach number flows as well as for transonic flows

Leeds Beckett University’s Holistic, Institutional Approach to Academic Integrity

This opinion piece argues that universities need to take a more holistic institutional approach to academic integrity. It outlines how Leeds Beckett University has attempted to do this through the development of academic integrity policies and practice which aims to ensure fairness and consistency across our University

Saving phase: Injectivity and stability for phase retrieval

Recent advances in convex optimization have led to new strides in the phase retrieval problem over finite-dimensional vector spaces. However, certain fundamental questions remain: What sorts of measurement vectors uniquely determine every signal up to a global phase factor, and how many are needed to do so? Furthermore, which measurement ensembles lend stability? This paper presents several results that address each of these questions. We begin by characterizing injectivity, and we identify that the complement property is indeed a necessary condition in the complex case. We then pose a conjecture that 4M-4 generic measurement vectors are both necessary and sufficient for injectivity in M dimensions, and we prove this conjecture in the special cases where M=2,3. Next, we shift our attention to stability, both in the worst and average cases. Here, we characterize worst-case stability in the real case by introducing a numerical version of the complement property. This new property bears some resemblance to the restricted isometry property of compressed sensing and can be used to derive a sharp lower Lipschitz bound on the intensity measurement mapping. Localized frames are shown to lack this property (suggesting instability), whereas Gaussian random measurements are shown to satisfy this property with high probability. We conclude by presenting results that use a stochastic noise model in both the real and complex cases, and we leverage Cramer-Rao lower bounds to identify stability with stronger versions of the injectivity characterizations.Comment: 22 page

Fractured portraits: mapping migration faultlines

Through my art practice, this creative project explores gender identity, belonging and place using personal narrative. As an artist and migrant the purpose of this narrative is to explore my history, my community, and my individual story. I investigate being an involuntary British child migrant. My identity formation fractured when immigration disrupted my expectation for continuity and I lived contrapuntally with a foot in both worlds of the pre-emigration and post-immigration worlds. British migrants have not been encouraged to tell their stories of migration and resettlement. Historians and government policy did not deem it of value. British emigrants to Australia post-WWII were considered privileged and not ‘real’ migrants, expected to assimilate as if changing countries was like changing rooms. I investigate my ideas using a narrative mode of enquiry. A key assumption is that by entering into close association with one’s own or others’ lives, the method is useful to better understand the beliefs and motivations of others or the self. Telling my story is a key navigational strategy to re-chart my life and create artwork. My lived experiences are exemplars of issues regarding identity, patriarchy, history, place, memory, grief and loss, and the findings that I have produced are the focus of the research. I examine family artefacts in relation to these influences. I explore and map gendered identity when immigration fractured my expectations for continuity. The rich data obtained from memory, family artefacts and photographic albums, discussions with relatives and family, form the basis and best provide access to the kind of knowledge being explored. I gain insight and understanding of my own position and acquire at the same time a different perspective. This study covers new ground in the way it generates a deeper understanding of migrant identity and raises important issues that have significance for all Australian migrant communities. Australia is comprised of an Indigenous culture, with the overlay of a white settler colony and migrants from many countries. Narrative is used so that this country can maintain its history of the nation, community and individuals of this multicultural society. Telling stories through the creation of artworks generates a deeper understanding of migrant identity. I can make meaning and find a sense of belonging in whatever place within or outside of Australia that I inhabit. I reflect on how I have negotiated or broken the internalised code a culture supplies concerning how life should be experienced. My story becomes a narrative with a wider audience – one relevant to Australian identity. If the culture fails to tell stories, we face becoming a monolithic ‘one size fits all’ nation

Temporal and Vertical Oxygen Gradients Modulate Nitrous Oxide Production in a Seasonally Anoxic Fjord: Saanich Inlet, British Columbia

Nitrous oxide (N2O) is a strong greenhouse gas and an ozone depleting agent. In marine environments, N2O is produced biologically via ammonium oxidation, nitrite, and nitrate reduction. The relative importance of these principle production pathways is strongly influenced by oxygen availability. We conducted 15N tracer experiments of N2O production in parallel with measurements of N2O concentration and natural abundance isotopes/isotopomers in Saanich Inlet, a seasonally anoxic fjord, to investigate how temporal and vertical oxygen gradients regulate N2O production pathways and rates. In April, June, and August 2018, the depth of the oxic‐anoxic interface (dissolved oxygen = 2.5 μmol L−1 isoline) progressively deepened from 110 to 160 m. Within the oxygenated and suboxic water column, N2O supersaturation coincided with peak ammonium oxidation activity. Conditions in the anoxic deep water were potentially favorable to N2O production from nitrate and nitrite reduction, but N2O undersaturation was observed indicating that N2O consumption exceeded rates of production. In October, tidal mixing introduced oxygenated water from outside the inlet, displacing the suboxic and anoxic deep water. This oxygenation event stimulated N2O production from ammonium oxidation and increased water column N2O supersaturation while inhibiting nitrate and nitrite reduction to N2O. Results from 15N tracer incubation experiments and natural abundance isotopomer measurements both implicated ammonium oxidation as the dominant N2O production pathway in Saanich Inlet, fueled by high ammonium fluxes (0.6–3.5 nmol m−2 s−1) from the anoxic depths. Partial denitrification contributed little to water column N2O production because of low availability of nitrate and nitrite

Spatial knowledge management and participatory governance: rethinking the trajectories of urban, socio-economic and environmental change and the politics of 'sustainability' in southern cities

This paper presents the analytical framework developed iteratively by the research team of the Chance2Sustain (C2S) research project between 2010 and July 2014, in order to answer the main research question which was posed at the outset of the research, namely : how can spatial knowledge management (SKM) and participatory governance contribute to sustainable urban development ? To answer this question, the C2S project was designed to undertake comparative empirical research in 10 cities in four fast-growing countries of the South to understand the role of SKM and participatory processes in facing the challenges in a number of strategic domains of urban development ; those of economic growth, social inequality and vulnerability, and environmental governance. In each city, there were researchers from both the North and South working together in the five domains of economic growth through megaprojects ; social mobilisation and social exclusion in sub-standard settlements ; environmental governance with the focus on water-related issues ; spatial knowledge management; and fiscal decentralisation and participatory city budgeting