Three Dimensional Software Modelling

Traditionally, diagrams used in software systems modelling have been two dimensional (2D). This is probably because graphical notations, such as those used in object-oriented and structured systems modelling, draw upon the topological graph metaphor, which, at its basic form, receives little benefit from three dimensional (3D) rendering. This paper presents a series of 3D graphical notations demonstrating effective use of the third dimension in modelling. This is done by e.g., connecting several graphs together, or in using the Z co-ordinate to show special kinds of edges. Each notation combines several familiar 2D diagrams, which can be reproduced from 2D projections of the 3D model. 3D models are useful even in the absence of a powerful graphical workstation: even 2D stereoscopic projections can expose more information than a plain planar diagram

Wind turbine condition assessment through power curve copula modeling

Power curves constructed from wind speed and active power output measurements provide an established method of analyzing wind turbine performance. In this paper it is proposed that operational data from wind turbines are used to estimate bivariate probability distribution functions representing the power curve of existing turbines so that deviations from expected behavior can be detected. Owing to the complex form of dependency between active power and wind speed, which no classical parameterized distribution can approximate, the application of empirical copulas is proposed; the statistical theory of copulas allows the distribution form of marginal distributions of wind speed and power to be expressed separately from information about the dependency between them. Copula analysis is discussed in terms of its likely usefulness in wind turbine condition monitoring, particularly in early recognition of incipient faults such as blade degradation, yaw and pitch errors

Interactions of Satellite Galaxies in Cosmological Dark Matter Halos

We present a statistical analysis of the interactions between satellite galaxies in cosmological dark matter halos taken from fully self-consistent high-resolution simulations of galaxy clusters. We show that the number distribution of satellite encounters has a tail that extends to as many as 3-4 encounters per orbit. On average 30% of the substructure population had at least one encounter (per orbit) with another satellite galaxy. However, this result depends on the age of the dark matter host halo with a clear trend for more interactions in younger systems. We also report a correlation between the number of encounters and the distance of the satellites to the centre of the cluster: satellite galaxies closer to the centre experience more interactions. However, this can be simply explained by the radial distribution of the substructure population and merely reflects the fact that the density of satellites is higher in those regions. In order to find substructure galaxies we applied (and present) a new technique based upon the N-body code MLAPM. This new halo finder MHF (MLAPM's-Halo-Finder) acts with exactly the same accuracy as the N-body code itself and is therefore free of any bias and spurious mismatch between simulation data and halo finding precision related to numerical effects.Comment: 6 pages, 4 figures, accepted by PASA (refereed contribution to the 5th Galactic Chemodynamics workshop, July 2003

Mapping Substructures in Dark Matter Halos

We present a detailed study of the real and integrals-of-motion space distributions of a satellite obtained from a self-consistent high-resolution simulation of a galaxy cluster and re-simulated using various analytical halo potentials. We found that the disrupted satellite appears as a coherent structure in integrals-of-motion space in all models (``live'' and analytical potential) although the distribution is significantly smeared for the live host halo. Further the primary mechanism for this smearing is the mass growth of the host, which changes both the energy and angular momentum of the satellite debris. Hence, this must be considered when searching for (stellar) streams with future observational experiments such as RAVE and GAIA.Comment: 5 pages, 6 figures, MNRAS accepted - minor editing without changing the conclusions, a high-resolution version of the paper is available from http://astronomy.swin.edu.au/~sgill/downloads/downloads.htm

Shaftesbury on Persons, Personal Identity, and Character Development

Shaftesbury’s major work Characteristicks of Men, Manners, Opinions, Times was one of the most influential English works in the eighteenth century. This paper focuses on his contributions to debates about persons and personal identity and shows that Shaftesbury regards metaphysical questions of personal identity as closely connected with normative questions of character development. I argue that he is willing to accept that persons are substances and that he takes their continued existence for granted. He sees the need to supplement metaphysical debates of personal identity and believes that we have to turn to the character that is realized by a substance if we want to understand who we are. For Shaftesbury persons have a particular character, can act, and govern themselves. I propose that Shaftesbury’s approach to persons has a developmental dimension, which is meant to encourage personal development and improvement of character. The developmental dimension can be understood as an intellectual journey that invites us to search for our true self, to develop our character, and to seek happiness, which ultimately involves understanding our place as persons in the order of the universe. I show that my developmental interpretation is preferable to other existing interpretations

Distributed electricity markets and distribution locational marginal prices : a review

As part of the transition from distribution network operator to distribution system operator (DSO), decentralised pricing of energy is an area that needs to be considered. This paper considers different roles for the DSO in facilitating distributed markets including the decentralised and centralised approaches. The latest work in distributed markets has been reviewed including two major pilot projects involving DSO type operation of distribution markets. The use of distribution locational marginal prices (DLMPs) in distributed markets has been studied as a promising means of directing investment and managing constraints in distribution systems. Some simple case studies involving DLMPs in an example distribution network were modelled using Matpower and it was seen that marginal prices could result in reduced losses and congestion if DLMPs are passed on to distributed energy resources. A case was considered of a bus with losses resulting in DLMPs 6% above the grid import cost and it was seen if the DLMP market was used a generator installed at this bus could reduce the cost of losses by up to 14%

Cosmology on a Mesh

An adaptive multi grid approach to simulating the formation of structure from collisionless dark matter is described. MLAPM (Multi-Level Adaptive Particle Mesh) is one of the most efficient serial codes available on the cosmological 'market' today. As part of Swinburne University's role in the development of the Square Kilometer Array, we are implementing hydrodynamics, feedback, and radiative transfer within the MLAPM adaptive mesh, in order to simulate baryonic processes relevant to the interstellar and intergalactic media at high redshift. We will outline our progress to date in applying the existing MLAPM to a study of the decay of satellite galaxies within massive host potentials.Comment: 3 pages, 2 figures, to appear in the proceedings of "The IGM/Galaxy Connection - The Distribution of Baryons at z=0", ed. M. Putman & J. Rosenber

Inequalities in student to course match: evidence from linked administrative data

This paper examines inequalities in the match between student quality and university quality using linked administrative data from schools, universities and tax authorities. We analyse two measures of match at the university-subject (course) level, based on student academic attainment, and graduate earnings. We find that students from lower socio-economic groups systematically undermatch for both measures across the distribution of attainment, with particularly stark socio-economic gaps for the most undermatched. While there are negligible gender gaps in academic match, high-attaining women systematically undermatch in terms of expected earnings, largely driven by subject choice

Radial Alignment in Simulated Clusters

Observational evidence for the radial alignment of satellites with their dark matter host has been accumulating steadily in the past few years. The effect is seen over a wide range of scales, from massive clusters of galaxies down to galaxy-sized systems, yet the underlying physical mechanism has still not been established. To this end, we have carried out a detailed analysis of the shapes and orientations of dark matter substructures in high-resolution N-body cosmological simulations. We find a strong tendency for radial alignment of the substructure with its host halo: the distribution of halo major axes is very anisotropic, with the majority pointing towards the center of mass of the host. The alignment peaks once the sub-halo has passed the virial radius of the host for the first time, but is not subsequently diluted, even after the halos have gone through as many as four pericentric passages. This evidence points to the existence of a very rapid dynamical mechanism acting on these systems and we argue that tidal torquing throughout their orbits is the most likely candidate.Comment: v2: 13 pages, 10 figures, ApJ in press. Revisions include a new section (4.2) comparing our results with observations, and a few added reference