Quaternionic Formulation of the Dirac Equation

The Dirac equation with Lorentz violation involves additional coefficients and yields a fourth-order polynomial that must be solved to yield the dispersion relation. The conventional method of taking the determinant of $4\times 4$ matrices of complex numbers often yields unwieldy dispersion relations. By using quaternions, the Dirac equation may be reduced to $2 \times 2$ form in which the structure of the dispersion relations become more transparent. In particular, it is found that there are two subsets of Lorentz-violating parameter sets for which the dispersion relation is easily solvable. Each subset contains half of the parameter space so that all parameters are included.Comment: Presented at the Fifth Meeting on CPT and Lorentz Symmetry, Bloomington, Indiana, June 28-July 2, 201

Exploring the line of descent in the intergenerational transmission of domestic property

While there has been growing interest in the intergenerational transmission of domestic property over recent years—and specifically housing inheritance—the line of descent in this transmission has been ignored. We do not know whether domestic property goes disproportionately to the next generation(s) of men, or to the women, or equally to men and women as the Western bilateral system of descent would dictate. Using published empirical research and data from a sample of Brisbane households, this paper tests an argument proffered by two European sociologists, Delphy and Leonard. They maintain that domestic property goes disproportionately to the next generation(s) of men because of the power of patriarchy. However, the Brisbane data showed that domestic property went roughly equally to the next generations of men and women, suggesting the presence of a bilateral system of descent. Conceptual and theoretical implications arising from this finding, relative to Delphy and Leonard's claim, are examined in the last part ofthe paper.Australian Policy Online (APO)'s Linked Data II project, funded by the Australian Research Council, with partners at the ANU Library, Swinburne University and RMIT

The circuit and cocircuit lattices of a regular matroid

A matroid abstracts the notions of dependence common to linear algebra, graph theory, and geometry. We show the equivalence of some of the various axiom systems which define a matroid and examine the concepts of matroid minors and duality before moving on to those matroids which can be represented by a matrix over any field, known as regular matroids. Placing an orientation on a regular matroid allows us to define certain lattices (discrete groups) associated to the matroid. These allow us to construct the Jacobian group of a regular matroid analogous to the Jacobian group of a graph. We then survey some recent work characterizing the matroid Jacobian. Finally we extend some results due to Eppstein concerning the Jacobian group of a graph to the case of regular matroids

Hello World! I am Charlie, an Artificially Intelligent Conference Panelist

In recent years, advances in artificial intelligence (AI) have far outpaced our ability to understand and leverage them. In no domain has this been more true than in conversational agents (CAs). Transformer-based generative language models, such as GPT-2, significantly advance CAs\u27 ability to generate creative and relevant content. It is critical to start exploring collaboration with these CAs. In this paper, we focus on an initial step by enabling a human-augmented, AI-driven CA to contribute to a panel discussion. Key questions include training a transformer-based AI to talk like a panelist, effectively embodying the CA to interact with panel participants, and defining the operational requirements and challenges to a CA gaining acceptance from its peers. Our results highlight the benefits that varied training, equal and dynamic representation, and fluid operation can have for AI applications. While acknowledging limitations, we present a path forward to richer, more natural human-AI collaboration

Facing Forward: Policy for Automated Facial Expression Analysis

The human face is a powerful tool for nonverbal communication. Technological advances have enabled widespread and low-cost deployment of video capture and facial recognition systems, opening the door for automated facial expression analysis (AFEA). This paper summarizes current challenges to the reliability of AFEA systems and challenges that could arise as a result of reliable AFEA systems. The potential benefits of AFEA are considerable, but developers, prospective users, and policy makers should proceed with caution

The challenges facing non-governmental organisations in transforming conflict through capacity-building in Nothern Uganda

Capacity-building is an essential component of post-conflict reconstruction (PCR) and peace-building in the aftermath of violent conflict. Civilians, mainly women and children are driven or abducted from their homes during violent conflict and suffer various abuses and atrocities. Many spend the duration of the conflict as refugees in Internally Displaced People (IDP) camps in neighbouring countries. Violent conflict impinges on their psychological well-being and socio-economic development making their re-integration into their former communities extremely complex and challenging. In the case of Northern Uganda, the conflict lasted for over two decades. However, since the ―Cessation of Hostilities Agreement‖ of 2006, the peace-building process has been particularly evident here. Numerous stakeholders have been involved in the capacity-building processes in Northern Uganda, and one such organisation is the Friends of Orphans (FRO) in Pader district, Northern Uganda. The purpose of this research study is to explore the challenges facing the FRO in transforming conflict and building sustainable peace through capacity-building in Pader district. The study explores the programmes the organisation implements and investigates how these programmes are relevant for the transformation of conflict. Apart from reviewing the literature, the researcher conducted semi-structured interviews and used participant observation. The employees of the FRO – all of whom are involved with capacity-building in these communities – participated in these interviews in their capacities as social workers, teachers, administrators and field workers. The beneficiaries of these programmes include former child soldiers, abductees, child mothers, land mine survivors and orphans. Lessons learned by the FRO, as well as the researcher‘s recommendations, are discussed in the study in order to assist the future work of the organisation and other stakeholders who have devoted their efforts to the recovery of areas emerging from conflict

Leap into... Problem-based Learning

Part of a collection of documents from Leap, formerly a University of Adelaide website providing information about learning and teaching initiatives at the University, archived in PDF format 26th April 2012.This publication is aimed primarily at the university teacher who wishes to explore this approach for the first time, but may also be useful to the teacher who has been dabbling in PBL for a while. The object of this publication is to create a relatively simple structure around which you can build your own PBL course.Margaret Kiley, Gerry Mullins, Ray Peterson and Tim Roger

Chemical contrast in STM imaging of transition metal aluminides

The present manuscript reviews recent scanning tunnelling microscopy (STM) studies of transition metal (TM) aluminide surfaces. It provides a general perspective on the contrast between Al atoms and TM atoms in STM imaging. A general trend is the much stronger bias dependence of TM atoms, or TM-rich regions of the surface. This dependence can be attenuated by the local chemical arrangements and environments. Al atoms can show a stronger bias dependence when their chemical environment, such as their immediate subsurface, is populated with TM. All this is well explained in light of combined results of STM and both theoretical and experimental electronic and crystallographic structure determinations. Since STM probes the Fermi surface, the electronic structure in the vicinity of the Fermi level (EF) is essential forunderstanding contrast and bias dependence. Hence, partial density of states provides information about the TM d band position and width, s–p–d hybridization or interactions, or charge transfer between constituent elements. In addition, recent developments in STM image simulations are very interesting for elucidating chemical contrast at Al–TM alloy surfaces, and allow direct atomic identification, when the surface does not show too much disorder. Overall, we show that chemically-specific imaging is often possible at these surfaces