15,364 research outputs found
Multimessenger Parameter Estimation of GW170817
We combine gravitational wave (GW) and electromagnetic (EM) data to perform a
Bayesian parameter estimation of the binary neutron star (NS) merger GW170817.
The EM likelihood is constructed from a fit to a large number of numerical
relativity simulations which we combine with a lower bound on the mass of the
remnant's accretion disk inferred from the modeling of the EM light curve. In
comparison with previous works, our analysis yields a more precise
determination of the tidal deformability of the binary, for which the EM data
provide a lower bound, and of the mass ratio of the binary, with the EM data
favoring a smaller mass asymmetry. The 90\% credible interval for the areal
radius of a NS is found to be (statistical and systematic uncertainties).Comment: 7 pages, 3 figures, accepted to the EPJA Topical Issue: The first
Neutron Star Merger Observation - Implications for Nuclear Physic
Labour Market Outcomes for Young Graduates
This paper examines income and employment outcomes for 18 to 30 year old New Zealanders with post-school qualifications, using data from the 1996 and 2001 Censi. Outcomes are analysed by field of study, to highlight the variation in outcomes within the post-school graduate (PSG) population. Fields are characterised according to the specialisation of job choices made by PSGs. A preliminary investigation is undertaken of changes in supply and demand of PSGs in different fields. Part A of the report summarises patterns for all PSGs, and compares fields of study. Part B contains field profiles for each of 26 grouped fields of study that can be compared across the two years.Labour Market outcomes, Tertiary Qualification, Young Graduates, New Zealand
An Approach to Cope with Ontology Changes for Ontology-based Applications
Keeping track of ontology changes is becoming a critical issue for ontology-based applications because updating an ontology that is in use may result in inconsistencies between the ontology and the knowledge base, dependent ontologies and dependent applications/services. Current research concentrates on the creation of ontologies and how to manage ontology changes in terms of the attempts to ease the communications between ontology versions and keep consistent with the instances, and there is little work available on controlling the impact to dependent applications/services which is the aims of the system presented in this paper. The approach we propose in this paper is to manually capture and log ontology changes, use this log to analyse incoming RDQL queries and amend them as necessary. Revised queries can then be used to query the knowledge base of the applications/services. We present the infrastructure of our approach based on the problems and scenarios identified within ontology-based systems. We discuss the issues met during our design and implementation, and consider some problems whose solutions will be beneficial to the development of our approach
Financing Capture Ready Coal-Fired Power Plants in China by Issuing Capture Options
‘Capture Ready’ is a design concept enabling fossil fuel plants to be retrofitted more economically with carbon dioxide capture and storage (CCS) technologies, however financing the cost of capture ready can be problematic, especially in the developing world. We propose that fossil fuel plants issue tradable Capture Options to acquire financing. The Capture Option concept could move CCS forward politically in countries such as China, speed up CCS technology development, help Capture Ready investors diversify risk, and offer global warming investors an alternative investment opportunity. As a detailed case study, we assess the value of a Capture Option and Capture Ready plant for a 600 MW supercritical pulverized coal power plant in China, using a cash flow model with Monte-Carlo simulations. The gross value of Capture Ready varies from CNY3m (84.4m) at an 8% discount rate and the Capture Option is valued at CNY113m (167.3m) for two of the four scenarios analyzed
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