Processes on Unimodular Random Networks

We investigate unimodular random networks. Our motivations include their characterization via reversibility of an associated random walk and their similarities to unimodular quasi-transitive graphs. We extend various theorems concerning random walks, percolation, spanning forests, and amenability from the known context of unimodular quasi-transitive graphs to the more general context of unimodular random networks. We give properties of a trace associated to unimodular random networks with applications to stochastic comparison of continuous-time random walk.Comment: 66 pages; 3rd version corrects formula (4.4) -- the published version is incorrect --, as well as a minor error in the proof of Proposition 4.10; 4th version corrects proof of Proposition 7.1; 5th version corrects proof of Theorem 5.1; 6th version makes a few more minor correction

Innovative strategies for 3D visualisation using photogrammetry and 3D scanning for mobile phones

3D model generation through Photogrammetry is a modern overlay of digital information representing real world objects in a virtual world. The immediate scope of this study aims at generating 3D models using imagery and overcoming the challenge of acquiring accurate 3D meshes. This research aims to achieve optimised ways to document raw 3D representations of real life objects and then converting them into retopologised, textured usable data through mobile phones. Augmented Reality (AR) is a projected combination of real and virtual objects. A lot of work is done to create market dependant AR applications so customers can view products before purchasing them. The need is to develop a product independent photogrammetry to AR pipeline which is freely available to create independent 3D Augmented models. Although for the particulars of this research paper, the aim would be to compare and analyse different open source SDK’s and libraries for developing optimised 3D Mesh using Photogrammetry/3D Scanning which will contribute as a main skeleton to the 3D-AR pipeline. Natural disasters, global political crisis, terrorist attacks and other catastrophes have led researchers worldwide to capture monuments using photogrammetry and laser scans. Some of these objects of “global importance” are processed by companies including CyArk (Cyber Archives) and UNESCO’s World Heritage Centre, who work against time to preserve these historical monuments, before they are damaged or in some cases completely destroyed. The need is to question the significance of preserving objects and monuments which might be of value locally to a city or town. What is done to preserve those objects? This research would develop pipelines for collecting and processing 3D data so the local communities could contribute towards restoring endangered sites and objects using their smartphones and making these objects available to be viewed in location based AR. There exist some companies which charge relatively large amounts of money for local scanning projects. This research would contribute as a non-profitable project which could be later used in school curriculums, visitor attractions and historical preservation organisations all over the globe at no cost. The scope isn’t limited to furniture, museums or marketing, but could be used for personal digital archiving as well. This research will capture and process virtual objects using Mobile Phones comparing methodologies used in Computer Vision design from data conversion on Mobile phones to 3D generation, texturing and retopologising. The outcomes of this research will be used as input for generating AR which is application independent of any industry or product

Sheep and goats:manipulating visual perception through colour relationships

Sheep and Goats hides visual messages in plain sight. It is a print diptych which investigates the idea that artwork can be intentionally created to be experienced differently dependent on one’s visual abilities. Each silk-screened/ink-jet print is 84 cm x 112 cm. It is accompanied by a smart device fitted with augmented reality colour vision deficiency simulation and recolouring software. The collaboration of artist David Lyons with computer scientist David Flatla resulted in prints which communicate unique details exclusively to those colour blindness, while simultaneously containing imagery that those with typical colour vision experience. This was done through the use and understanding of colour theory, artistic principles and computer science applications. All the artwork is revealed to both audiences through the use of tablets whose software allows the translation of the imagery between the two audiences. The tablets with CVD simulation and recolouring software allow those with typical colour sight to view what those with colour blindness see, and those with colour blindness to gain an appreciation of what individuals with typical sight see.To indicate engagement of audiences of varied colour vision abilities, Triple Blind reference the circles of the Ishihara Colour Blind Test. The dualistic words ‘heaven’ and ‘HELL’ are used to suggest conflicting perceptions as are the clear varnish over-printed lyrics from the song “Sheep go to Heaven’ by the rock band Cake. This paper documents the development of the work, its theoretical underpinnings and artistic and social and philosophical implications

Time-Varying Liquidity in Foreign Exchange

This paper addresses whether currency trades have greater price impact during periods of rapid public information flow. Central bankers often suggest that expectations are at times “ripe” for coordinated adjustment, and that periods of rapid information flow are such a time. We develop an optimizing model to account for the joint behavior of order flow and returns around announcements. Using transaction data made available by electronic trading, we estimate the price impact of trades in the DM/$ market precisely. We then test whether trades during periods with macroeconomic announcements have higher price impact. They do. We also test for dependence of liquidity on trading volume and return volatility (two other prominent state variables in the literature on liquidity variation). We do not find any evidence that liquidity depends on these variables. The findings provide policy-makers with guidance for the timing and magnitude intervention.

Lightweight Call-Graph Construction for Multilingual Software Analysis

Analysis of multilingual codebases is a topic of increasing importance. In prior work, we have proposed the MLSA (MultiLingual Software Analysis) architecture, an approach to the lightweight analysis of multilingual codebases, and have shown how it can be used to address the challenge of constructing a single call graph from multilingual software with mutual calls. This paper addresses the challenge of constructing monolingual call graphs in a lightweight manner (consistent with the objective of MLSA) which nonetheless yields sufficient information for resolving language interoperability calls. A novel approach is proposed which leverages information from a compiler-generated AST to provide the quality of call graph necessary, while the program itself is written using an Island Grammar that parses the AST providing the lightweight aspect necessary. Performance results are presented for a C/C++ implementation of the approach, PAIGE (Parsing AST using Island Grammar Call Graph Emitter) showing that despite its lightweight nature, it outperforms Doxgen, is robust to changes in the (Clang) AST, and is not restricted to C/C++.Comment: 10 page

Two-component equations modelling water waves with constant vorticity

In this paper we derive a two-component system of nonlinear equations which model two-dimensional shallow water waves with constant vorticity. Then we prove well-posedness of this equation using a geometrical framework which allows us to recast this equation as a geodesic flow on an infinite dimensional manifold. Finally, we provide a criteria for global existence.Comment: 24 page

Werner state structure and entanglement classification

We present applications of the representation theory of Lie groups to the analysis of structure and local unitary classification of Werner states, sometimes called the {\em decoherence-free} states, which are states of $n$ quantum bits left unchanged by local transformations that are the same on each particle. We introduce a multiqubit generalization of the singlet state, and a construction that assembles these into Werner states.Comment: 9 pages, 2 figures, minor changes and corrections for version

Consistency in statistical moments as a test for bubble cloud clustering

Frequency dependent measurements of attenuation and/or sound speed through clouds of gas bubbles in liquids are often inverted to find the bubble size distribution and the void fraction of gas. The inversions are often done using an effective medium theory as a forward model under the assumption that the bubble positions are Poisson distributed (i.e., statistically independent). Under circumstances in which single scattering does not adequately describe the pressure field, the assumption of independence in position can yield large errors when clustering is present, leading to errors in the inverted bubble size distribution. It is difficult, however, to determine the existence of clustering in bubble clouds without the use of specialized acoustic or optical imaging equipment. A method is described here in which the existence of bubble clustering can be identified by examining the consistency between the first two statistical moments of multiple frequency acoustic measurements

Pleasure, profit and pain: Alcohol in New Zealand and the contemporary culture of intoxication

This book details the rich, complex and often contested role of alcohol in New Zealand society. It explores the three fundamental alcohol rights that continue to fight for dominance of the national drinking culture: the rights of individual drinkers to enjoy the pleasures of alcohol, the rights of society to protect itself from the harms of alcohol, and the rights of the alcohol industry to profit from the sale of a legal commodity. Historically, most of our intoxicated drinkers were adult males and drinking was typically separated from family, food and entertainment. With the sweeping social changes of the 1960s and 1970s, women and later young people, increasingly engaged with alcohol. A growing proportion of these groups have since joined men in a culture of intoxication, or binge drinking culture as it is often termed. New Zealand is not alone however, in having a culture of intoxication, with similar alcohol consumption patterns evident in many other developed nations. This book identifies the local and the global influences that have affected New Zealand society (and much of the rest of the world) since the late 1900s and details how these influences have sustained the contemporary culture of intoxication. Finally, this book will propose that to implement effective change to our national drinking culture, the rights of the alcohol industry and of individual drinkers will need to be pulled back from the liberal excesses that the 1980s and 1990s provided. A re-balancing is required in order to strengthen and sustain society’s right to protect itself from alcohol-related harm

Stochastic Differential Equations Driven by Fractional Brownian Motion and Standard Brownian Motion

We prove an existence and uniqueness theorem for solutions of multidimensional, time dependent, stochastic differential equations driven simultaneously by a multidimensional fractional Brownian motion with Hurst parameter H>1/2 and a multidimensional standard Brownian motion. The proof relies on some a priori estimates, which are obtained using the methods of fractional integration, and the classical Ito stochastic calculus. The existence result is based on the Yamada-Watanabe theorem.Comment: 21 page