UNSW Canberra

Publication Search Results

Now showing 1 - 6 of 6
  • (2006) Lees, Brian; Van Niel, Kimberley; Laffan, Shawn
    Conference Paper

  • (2006) Maddison, Sarah; Lommen, D; Wright, Christopher; Bourke, Tyler; Jorgensen, J; Van Dishoeck, E; Burton, Michael; Hughes, A; Wilner, D
    Conference Paper
    In order to understand planet formation, we need to probe the physical conditions of protoplanetary disks to see when and where grains begin to grow in size. Over the past four years we have been conducting a 3mm continuum survey with the Australia Telescope Compact Array of disks around young stars (both T Tauri and Herbig Ae/B stars) in southern molecular clouds to investigate the evolution of protoplanetary disks and grain growth within these disks. The goals of our project are to obtain fluxes and hence determine the millimetre spectral energy indices, which provides information about the grain size distribution. We present results from our successful 2005 millimetre season, in which we observed 15 southern T Tauri sources (10 in Chamaeleon and 5 in Lupus). The opacity indices suggest the presence of mm-sized dust aggregates and hence substantial grain growth in the majority of these disks. We also present preliminary results from our follow-up 2006 observations of three sources (HD100546, WW Cha and RU Lup) are centimetre wavelengths and discuss the possibility of detecting pebble-sized "grains" in these disks.

  • (2006) Gwinner, G; Gomez, E; Orozco, L; Galvan, A; Sheng, D; Zhao, Yunjie; Sprouse, G; Behr, J; Jackson, K; Pearson, Mark; Aubin, S; Flambaum, Victor
    Journal Article

  • (2006) Zhang, Fei; Macnicol, James; Pickering, Mark; Frater, Michael; Arnold, John
    Journal Article
    We investigate streaming video over Differentiated Services (Diffserv) networks that can provide a number of aggregated traffic classes with increasing quality guarantee. We propose a method to measure the loss impact of a video packet on the quality of the decoded video images. We show how the optimal Quality-of-Service (QoS) mapping from the video packets into a set of traffic classes depends on the loss rates of the classes and the pricing model, and we develop an algorithm to accurately find the optimal QoS mapping. The performance of our algorithm is evaluated through computer simulations and compares favorably to an existing algorithm.

  • (2006) Pota, Hemanshu R.; Athanasius, Germane Xavier; Ugrinovskii, Valery; Li, Li
    Conference Paper
    This paper addresses the problem of designing a decentralized control of interconnected power systems, with OLTC and SVCs, under large changes in real and reactive loads that cause large structural changes in the system model. In addition to this, small changes in load are regulated by small disturbance controllers whose gains are adjusted for variations in power system model due to large changes in loads. The only feedback needed by subsystem controllers is the state of the subsystem itself. The design is carried out within a large-scale Markov jump parameter systems framework. In this paper, unlike other control schemes, OLTC transformers are used to damp power-angle oscillations. Simulation results are presented to demonstrate the performance of the designed controller.

  • (2006) Ranasinghe, Roshanka; Turner, Ian; Symonds, Graham
    Journal Article
    The results of a series of 2DH numerical and 3D scaled physical modelling tests indicate that processes governing shoreline response to submerged structures, such as artificial surfing reefs, are different from those associated with emergent offshore breakwaters. Unlike the case of emergent offshore breakwaters, where shoreline accretion (salient development) is expected under all structural/environmental conditions, the principal mode of shoreline response to submerged structures can vary between erosive and accretive, depending on the offshore distance to the structure. The predominant wave incidence angle and structure crest level also have important implications on the magnitude of shoreline response, but not on the mode of shoreline response (i.e. erosion vs. accretion). Based on the results obtained here, a predictive empirical relationship is proposed as a preliminary engineering tool to assess shoreline response to submerged structures. Crown Copyright (C) 2006 Published by Elsevier B.V. All rights reserved.