277 research outputs found
The International Criminal Court, National Security, And Compliance With International Law
Thank you, Mark, for your kind introduction. The question before the panel today is whether the United States, actions regarding national security over the last year or so are in harmony with international law, or, in the alternative, are the United States, policies on a collision course with international law
Global and Going Nowhere: Sustainable Development, Global Governance &(and) Liberal Democracy
International Law of Armed Conflict and Computer Network Attack: Developing the Rules of Engagement
INCMap: A Journey towards ontology-based data integration
Ontology-based data integration (OBDI) allows users to federate over heterogeneous data sources using a semantic rich conceptual data model. An important challenge in ODBI is the curation of mappings between the data sources and the global ontology. In the last years, we have built IncMap, a system to semi-automatically create mappings between relational data sources and a global ontology. IncMap has since been put into practice, both for academic and in industrial applications. Based on the experience of the last years, we have extended the original version of IncMap in several dimensions to enhance the mapping quality: (1) IncMap can detect and leverage semantic-rich patterns in the relational data sources such as inheritance for the mapping creation. (2) IncMap is able to leverage reasoning rules in the ontology to overcome structural differences from the relational data sources. (3) IncMap now includes a fully automatic mode that is often necessary to bootstrap mappings for a new data source. Our experimental evaluation shows that the new version of IncMap outperforms its previous version as well as other state-of-the-art systems
LINVIEW: Incremental View Maintenance for Complex Analytical Queries
Many analytics tasks and machine learning problems can be naturally expressed
by iterative linear algebra programs. In this paper, we study the incremental
view maintenance problem for such complex analytical queries. We develop a
framework, called LINVIEW, for capturing deltas of linear algebra programs and
understanding their computational cost. Linear algebra operations tend to cause
an avalanche effect where even very local changes to the input matrices spread
out and infect all of the intermediate results and the final view, causing
incremental view maintenance to lose its performance benefit over
re-evaluation. We develop techniques based on matrix factorizations to contain
such epidemics of change. As a consequence, our techniques make incremental
view maintenance of linear algebra practical and usually substantially cheaper
than re-evaluation. We show, both analytically and experimentally, the
usefulness of these techniques when applied to standard analytics tasks. Our
evaluation demonstrates the efficiency of LINVIEW in generating parallel
incremental programs that outperform re-evaluation techniques by more than an
order of magnitude.Comment: 14 pages, SIGMO
Marine seismic surveys and ocean noise : time for coordinated and prudent planning
Marine seismic surveys use intense (eg >= 230 decibel [dB] root mean square [RMS]) sound impulses to explore the ocean bottom for hydrocarbon deposits, conduct geophysical research, and establish resource claims under the United Nations Convention on the Law of the Sea. The expansion of seismic surveys necessitates greater regional and international dialogue, partnerships, and planning to manage potential environmental risks. Data indicate several reasons for concern about the negative impacts of anthropogenic noise on numerous marine species, including habitat displacement, disruption of biologically important behaviors, masking of communication signals, chronic stress, and potential auditory damage. The sound impulses from seismic surveys - spanning temporal and spatial scales broader than those typically considered in environmental assessments - may have acute, cumulative, and chronic effects on marine organisms. Given the international and transboundary nature of noise from marine seismic surveys, we suggest the creation of an international regulatory instrument, potentially an annex to the existing International Convention on the Prevention of Pollution from Ships, to address the issue.Publisher PDFPeer reviewe
QuickSel: Quick Selectivity Learning with Mixture Models
Estimating the selectivity of a query is a key step in almost any cost-based
query optimizer. Most of today's databases rely on histograms or samples that
are periodically refreshed by re-scanning the data as the underlying data
changes. Since frequent scans are costly, these statistics are often stale and
lead to poor selectivity estimates. As an alternative to scans, query-driven
histograms have been proposed, which refine the histograms based on the actual
selectivities of the observed queries. Unfortunately, these approaches are
either too costly to use in practice---i.e., require an exponential number of
buckets---or quickly lose their advantage as they observe more queries.
In this paper, we propose a selectivity learning framework, called QuickSel,
which falls into the query-driven paradigm but does not use histograms.
Instead, it builds an internal model of the underlying data, which can be
refined significantly faster (e.g., only 1.9 milliseconds for 300 queries).
This fast refinement allows QuickSel to continuously learn from each query and
yield increasingly more accurate selectivity estimates over time. Unlike
query-driven histograms, QuickSel relies on a mixture model and a new
optimization algorithm for training its model. Our extensive experiments on two
real-world datasets confirm that, given the same target accuracy, QuickSel is
34.0x-179.4x faster than state-of-the-art query-driven histograms, including
ISOMER and STHoles. Further, given the same space budget, QuickSel is
26.8%-91.8% more accurate than periodically-updated histograms and samples,
respectively
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