3,831,718 research outputs found
Applications of wavelet-based compression to multidimensional Earth science data
A data compression algorithm involving vector quantization (VQ) and the discrete wavelet transform (DWT) is applied to two different types of multidimensional digital earth-science data. The algorithms (WVQ) is optimized for each particular application through an optimization procedure that assigns VQ parameters to the wavelet transform subbands subject to constraints on compression ratio and encoding complexity. Preliminary results of compressing global ocean model data generated on a Thinking Machines CM-200 supercomputer are presented. The WVQ scheme is used in both a predictive and nonpredictive mode. Parameters generated by the optimization algorithm are reported, as are signal-to-noise (SNR) measurements of actual quantized data. The problem of extrapolating hydrodynamic variables across the continental landmasses in order to compute the DWT on a rectangular grid is discussed. Results are also presented for compressing Landsat TM 7-band data using the WVQ scheme. The formulation of the optimization problem is presented along with SNR measurements of actual quantized data. Postprocessing applications are considered in which the seven spectral bands are clustered into 256 clusters using a k-means algorithm and analyzed using the Los Alamos multispectral data analysis program, SPECTRUM, both before and after being compressed using the WVQ program
Data Catalog Series for Space Science and Applications Flight Missions
The main purpose of the data catalog series is to provide descriptive references to data generated by space science flight missions. The data sets described include all of the actual holdings of the Space Science Data Center (NSSDC), all data sets for which direct contact information is available, and some data collections held and serviced by foreign investigators, NASA and other U.S. government agencies. This volume contains narrative descriptions of data sets from geostationary and high altitude scientific spacecraft and investigations. The following spacecraft series are included: Mariner, Pioneer, Pioneer Venus, Venera, Viking, Voyager, and Helios. Separate indexes to the planetary and interplanetary missions are also provided
Biomedical applications of NASA science and technology Final report, 15 Jun. 1967 - 14 Jul. 1968
Updated data on activities of biomedical applications team - biomedical applications of NASA science and technolog
Four lectures on probabilistic methods for data science
Methods of high-dimensional probability play a central role in applications
for statistics, signal processing theoretical computer science and related
fields. These lectures present a sample of particularly useful tools of
high-dimensional probability, focusing on the classical and matrix Bernstein's
inequality and the uniform matrix deviation inequality. We illustrate these
tools with applications for dimension reduction, network analysis, covariance
estimation, matrix completion and sparse signal recovery. The lectures are
geared towards beginning graduate students who have taken a rigorous course in
probability but may not have any experience in data science applications.Comment: Lectures given at 2016 PCMI Graduate Summer School in Mathematics of
Data. Some typos, inaccuracies fixe
Citizen science for cuneiform studies
This paper examines the potential applications of Citizen Science and Open Linked Data within a critical Web Science framework. Described here is a work-inprocess concerning an interdisciplinary, multiinstitutional project for the digitization, annotation and online dissemination of a large corpus of written material from ancient Mesopotamia. The paper includes an outline of the problems presented by a large, heterogeneous and incomplete dataset, as well as a discussion of the potential of Citizen Science as a potential solution, combining both technical and social aspects. Drawing inspiration from other successful Citizen Science projects, the current paper suggests a process for capturing and enriching the data in ways which can address not only the challenges of the current data set, but also similar issues arising elsewhere on the wider Web
Planetary Radio Interferometry and Doppler Experiment (PRIDE) Technique: a Test Case of the Mars Express Phobos Fly-by. 2. Doppler tracking: Formulation of observed and computed values, and noise budget
Context. Closed-loop Doppler data obtained by deep space tracking networks
(e.g., NASA's DSN and ESA's Estrack) are routinely used for navigation and
science applications. By "shadow tracking" the spacecraft signal, Earth-based
radio telescopes involved in Planetary Radio Interferometry and Doppler
Experiment (PRIDE) can provide open-loop Doppler tracking data when the
dedicated deep space tracking facilities are operating in closed-loop mode
only. Aims. We explain in detail the data processing pipeline, discuss the
capabilities of the technique and its potential applications in planetary
science. Methods. We provide the formulation of the observed and computed
values of the Doppler data in PRIDE tracking of spacecraft, and demonstrate the
quality of the results using as a test case an experiment with ESA's Mars
Express spacecraft. Results. We find that the Doppler residuals and the
corresponding noise budget of the open-loop Doppler detections obtained with
the PRIDE stations are comparable to the closed-loop Doppler detections
obtained with the dedicated deep space tracking facilities
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Disrupting Illicit Supply Networks: New Applications of Operations Research and Data Analytics to End Modern Slavery
Report from a 2017 National Science Foundation workshop on promising research directions for applications of operations research and data analytics toward the disruption of illicit supply networks like human trafficking. The workshop was funded by the NSF’s Operations Engineering (ENG) and the Law & Social Sciences Program (SBE) under grant # CMMI-1726895. The report addresses the opportunity to apply advances from the fields of operations research, management science, analytics, machine learning, and data science toward the development of disruptive interventions against illicit networks. Such an extension of the current research agenda for trafficking would move understanding of such dynamic systems from descriptive characterization and predictive estimation toward improved dynamic operational control.Bureau of Business Researc
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