14,835 research outputs found
GTOSS: Generalized Tethered Object Simulation System
GTOSS represents a tether analysis complex which is described by addressing its family of modules. TOSS is a portable software subsystem specifically designed to be introduced into the environment of any existing vehicle dynamics simulation to add the capability of simulating multiple interacting objects (via multiple tethers). These objects may interact with each other as well as with the vehicle into whose environment TOSS is introduced. GTOSS is a stand alone tethered system analysis program, representing an example of TOSS having been married to a host simulation. RTOSS is the Results Data Base (RDB) subsystem designed to archive TOSS simulation results for future display processing. DTOSS is a display post processors designed to utilize the RDB. DTOSS extracts data from the RDB for multi-page printed time history displays. CTOSS is similar to DTOSS, but is designed to create ASCII plot files. The same time history data formats provided for DTOSS (for printing) are available via CTOSS for plotting. How these and other modules interact with each other is discussed
Strengthening rules-based order in the Asia-Pacific
This paper explores the opportunities for both Australia and Japan jointly to promote their shared interest in strengthening the rule of law in the Asia–Pacific.
Overview
The rule of law is an essential condition if cooperation and orderly behaviour are to be advanced in the Asia–Pacific. We need norms and rules that guide—and govern—relations among regional states.
Australia and Japan share an interest in minimising the role that coercion plays in the Asia–Pacific and maximising cooperation across the region. We’re both liberal democracies, with a strong bilateral security relationship, an alliance with the United States and a genuine commitment to the rule of law.
All Asia–Pacific states would profit by following Australia and Japan’s example in promoting and abiding by the rule of law in their external policies. Indeed, our region would be a much safer place if they did.
ASPI has this year worked on a project to explore the opportunities for both Australia and Japan jointly to promote our shared interest in strengthening the rule of law in the Asia–Pacific. This report sets out the project’s key findings and outlines policy proposals to enhance Australia–Japan cooperation to bolster the rule of law in the region
Full-depth Coadds of the WISE and First-year NEOWISE-Reactivation Images
The Near Earth Object Wide-field Infrared Survey Explorer (NEOWISE)
Reactivation mission released data from its first full year of observations in
2015. This data set includes ~2.5 million exposures in each of W1 and W2,
effectively doubling the amount of WISE imaging available at 3.4 and 4.6
microns relative to the AllWISE release. We have created the first ever
full-sky set of coadds combining all publicly available W1 and W2 exposures
from both the AllWISE and NEOWISE-Reactivation (NEOWISER) mission phases. We
employ an adaptation of the unWISE image coaddition framework (Lang 2014),
which preserves the native WISE angular resolution and is optimized for forced
photometry. By incorporating two additional scans of the entire sky, we not
only improve the W1/W2 depths, but also largely eliminate time-dependent
artifacts such as off-axis scattered moonlight. We anticipate that our new
coadds will have a broad range of applications, including target selection for
upcoming spectroscopic cosmology surveys, identification of distant/massive
galaxy clusters, and discovery of high-redshift quasars. In particular, our
full-depth AllWISE+NEOWISER coadds will be an important input for the Dark
Energy Spectroscopic Instrument (DESI) selection of luminous red galaxy and
quasar targets. Our full-depth W1/W2 coadds are already in use within the DECam
Legacy Survey (DECaLS) and Mayall z-band Legacy Survey (MzLS) reduction
pipelines. Much more work still remains in order to fully leverage NEOWISER
imaging for astrophysical applications beyond the solar system.Comment: coadds available at http://unwise.me, zoomable full-sky rendering at
http://legacysurvey.org/viewe
Searching for comets on the World Wide Web: The orbit of 17P/Holmes from the behavior of photographers
We performed an image search for "Comet Holmes," using the Yahoo Web search
engine, on 2010 April 1. Thousands of images were returned. We astrometrically
calibrated---and therefore vetted---the images using the Astrometry.net system.
The calibrated image pointings form a set of data points to which we can fit a
test-particle orbit in the Solar System, marginalizing over image dates and
detecting outliers. The approach is Bayesian and the model is, in essence, a
model of how comet astrophotographers point their instruments. In this work, we
do not measure the position of the comet within each image, but rather use the
celestial position of the whole image to infer the orbit. We find very strong
probabilistic constraints on the orbit, although slightly off the JPL
ephemeris, probably due to limitations of our model. Hyperparameters of the
model constrain the reliability of date meta-data and where in the image
astrophotographers place the comet; we find that ~70 percent of the meta-data
are correct and that the comet typically appears in the central third of the
image footprint. This project demonstrates that discoveries and measurements
can be made using data of extreme heterogeneity and unknown provenance. As the
size and diversity of astronomical data sets continues to grow, approaches like
ours will become more essential. This project also demonstrates that the Web is
an enormous repository of astronomical information; and that if an object has
been given a name and photographed thousands of times by observers who post
their images on the Web, we can (re-)discover it and infer its dynamical
properties.Comment: As published. Changes in v2: data-driven initialization rather than
JPL; added figures; clarified tex
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