1,175 research outputs found

    Duration and Persistence in Multidimensional Deprivation: Methodology and Australian Application

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    This paper extends the recent literature on static multidimensional deprivation to propose dynamic deprivation measures that incorporate both the persistence and duration of deprivation across multiple dimensions. The paper then illustrates the usefulness of the extension by applying it to Australian panel data for the recent period, 2001-2008. The empirical application exploits the subgroup decomposability of the deprivation measures to identify the subgroups that are more deprived than others. The proposed measure is also decomposable by dimensions and is used to identify the dimensions where deprivation is more persistent. The comparison between the subgroups shows that the divide between homeowners and non-homeowners is one of the sharpest, with the latter suffering much more deprivation than the former. The results are robust to alternative schemes for weighting and aggregating the dimensions as well as to the choice of model parameters.Multidimensional Deprivation; Social Exclusion; Duration of Deprivation; Deprivation Persistence; Subgroup Decomposability.

    EVALUATING THE DISTRIBUTIONAL IMPLICATIONS OF PRICE MOVEMENTS: METHODOLOGY, APPLICATION AND AUSTRALIAN EVIDENCE

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    This paper investigates the distributional implication of inflation in Australia. It proposes and applies a method of evaluating the nature and size of the inequality bias of price movements. In the process, the study introduces a new demographic demand model that yields sensible and well determined estimates of the general equivalence scale and the size economies of scale. The study finds that inflation in Australia during the 1990s had an inequality increasing bias and that this bias increased in the late 1990s and the first part of the new millennium. The study also provides evidence on the decomposition of overall inequality between demographic groups and compares the decomposition between the nominal and real expenditure inequalities.Price scaling, demographic demand, real expenditure inequality, inequality aversion.

    On the anomalous afterglow seen in a chameleon afterglow search

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    We present data from our investigation of the anomalous orange-colored afterglow that was seen in the GammeV Chameleon Afterglow Search (CHASE). These data includes information about the broad band color of the observed glow, the relationship between the glow and the temperature of the apparatus, and other data taken prior to and during the science operations of CHASE. While differing in several details, the generic properties of the afterglow from CHASE are similar to luminescence seen in some vacuum compounds. Contamination from this, or similar, luminescent signatures will likely impact the design of implementation of future experiments involving single photon detectors and high intensity light sources in a cryogenic environment.Comment: 6 pages, 5 figures, submitted to PR

    Challenges of CPAS Flight Testing

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    The Crew Exploration Vehicle Parachute Assembly System (CPAS) is being designed to land the Orion Crew Module (CM) at a safe rate of descent at splashdown via a series of Drogue, Pilot, and Main parachutes. Because Orion is considerably larger and heavier than Apollo, many of the flight test techniques developed during the Apollo program must be modified. The Apollo program had a dedicated C-133 aircraft, which was modified to allow a simple airdrop of "boilerplate" flight test vehicles. However, the CPAS program must use either commercial or military assets with minimal modifications to airframes or procedures. Conceptual envelopes from 2-Degree Of Freedom trajectories are presented for several existing and novel architectures. Ideally, the technique would deliver a representative capsule shape to the desired altitude and dynamic pressure at test initiation. However, compromises must be made on the characteristics of trajectories or the fidelity of test articles to production hardware. Most of the tests to date have used traditional pallet and weight tub or missile-shaped test vehicles. New test vehicles are being designed to better incorporate Orion structural components and deploy parachutes in a more representative fashion. The first attempt to test a capsule-shaped vehicle failed due to unexpected events while setting up the test condition through a series of complex procedures. In order to avoid the loss of another expensive test article which will delay the program, simpler deployment methods are being examined and more positive control of the vehicle will be maintained. Existing challenges include interfacing with parent aircraft, separating test vehicles, achieving test conditions, and landing within limited test ranges. All these challenges must be met within cost and schedule limits

    Hydra-Multi: Collaborative Online Construction of 3D Scene Graphs with Multi-Robot Teams

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    3D scene graphs have recently emerged as an expressive high-level map representation that describes a 3D environment as a layered graph where nodes represent spatial concepts at multiple levels of abstraction (e.g., objects, rooms, buildings) and edges represent relations between concepts (e.g., inclusion, adjacency). This paper describes Hydra-Multi, the first multi-robot spatial perception system capable of constructing a multi-robot 3D scene graph online from sensor data collected by robots in a team. In particular, we develop a centralized system capable of constructing a joint 3D scene graph by taking incremental inputs from multiple robots, effectively finding the relative transforms between the robots' frames, and incorporating loop closure detections to correctly reconcile the scene graph nodes from different robots. We evaluate Hydra-Multi on simulated and real scenarios and show it is able to reconstruct accurate 3D scene graphs online. We also demonstrate Hydra-Multi's capability of supporting heterogeneous teams by fusing different map representations built by robots with different sensor suites.Comment: 8 pages, 10 figure

    Task and Motion Planning in Hierarchical 3D Scene Graphs

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    Recent work in the construction of 3D scene graphs has enabled mobile robots to build large-scale hybrid metric-semantic hierarchical representations of the world. These detailed models contain information that is useful for planning, however how to derive a planning domain from a 3D scene graph that enables efficient computation of executable plans is an open question. In this work, we present a novel approach for defining and solving Task and Motion Planning problems in large-scale environments using hierarchical 3D scene graphs. We identify a method for building sparse problem domains which enable scaling to large scenes, and propose a technique for incrementally adding objects to that domain during planning time to avoid wasting computation on irrelevant elements of the scene graph. We test our approach in two hand crafted domains as well as two scene graphs built from perception, including one constructed from the KITTI dataset. A video supplement is available at https://youtu.be/63xuCCaN0I4
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