90,188 research outputs found
A demonstration of ERTS-1 analog and digital techniques applied to strip mining in Maryland and West Virginia
The largest contour strip mining operations in western Maryland and West Virginia are located within the Georges Creek and the Upper Potomac Basins. These two coal basins lie within the Georges Creek (Wellersburg) syncline. The disturbed strip mine areas were delineated with the surrounding geological and vegetation features using ERTS-1 data in both analog (imagery) and digital form. The two digital systems used were: (1) the ERTS-Analysis system, a point-by-point digital analysis of spectral signatures based on known spectral values, and (2) the LARS Automatic Data Processing System. The digital techniques being developed will later be incorporated into a data base for land use planning. These two systems aided in efforts to determine the extent and state of strip mining in this region. Aircraft data, ground verification information, and geological field studies also aided in the application of ERTS-1 imagery to perform an integrated analysis that assessed the adverse effects of strip mining. The results indicated that ERTS can both monitor and map the extent of strip mining to determine immediately the acreage affected and indicate where future reclamation and revegetation may be necessary
Mining a medieval social network by kernel SOM and related methods
This paper briefly presents several ways to understand the organization of a
large social network (several hundreds of persons). We compare approaches
coming from data mining for clustering the vertices of a graph (spectral
clustering, self-organizing algorithms. . .) and provide methods for
representing the graph from these analysis. All these methods are illustrated
on a medieval social network and the way they can help to understand its
organization is underlined
Similarity-Aware Spectral Sparsification by Edge Filtering
In recent years, spectral graph sparsification techniques that can compute
ultra-sparse graph proxies have been extensively studied for accelerating
various numerical and graph-related applications. Prior nearly-linear-time
spectral sparsification methods first extract low-stretch spanning tree from
the original graph to form the backbone of the sparsifier, and then recover
small portions of spectrally-critical off-tree edges to the spanning tree to
significantly improve the approximation quality. However, it is not clear how
many off-tree edges should be recovered for achieving a desired spectral
similarity level within the sparsifier. Motivated by recent graph signal
processing techniques, this paper proposes a similarity-aware spectral graph
sparsification framework that leverages efficient spectral off-tree edge
embedding and filtering schemes to construct spectral sparsifiers with
guaranteed spectral similarity (relative condition number) level. An iterative
graph densification scheme is introduced to facilitate efficient and effective
filtering of off-tree edges for highly ill-conditioned problems. The proposed
method has been validated using various kinds of graphs obtained from public
domain sparse matrix collections relevant to VLSI CAD, finite element analysis,
as well as social and data networks frequently studied in many machine learning
and data mining applications
Specmine: an R package for metabolomics and spectral data analysis and mining
Book of Abstracts of CEB Annual Meeting 2017info:eu-repo/semantics/publishedVersio
Finding Young Stellar Populations in Elliptical Galaxies from Independent Components of Optical Spectra
Elliptical galaxies are believed to consist of a single population of old
stars formed together at an early epoch in the Universe, yet recent analyses of
galaxy spectra seem to indicate the presence of significant younger populations
of stars in them. The detailed physical modelling of such populations is
computationally expensive, inhibiting the detailed analysis of the several
million galaxy spectra becoming available over the next few years. Here we
present a data mining application aimed at decomposing the spectra of
elliptical galaxies into several coeval stellar populations, without the use of
detailed physical models. This is achieved by performing a linear independent
basis transformation that essentially decouples the initial problem of joint
processing of a set of correlated spectral measurements into that of the
independent processing of a small set of prototypical spectra. Two methods are
investigated: (1) A fast projection approach is derived by exploiting the
correlation structure of neighboring wavelength bins within the spectral data.
(2) A factorisation method that takes advantage of the positivity of the
spectra is also investigated. The preliminary results show that typical
features observed in stellar population spectra of different evolutionary
histories can be convincingly disentangled by these methods, despite the
absence of input physics. The success of this basis transformation analysis in
recovering physically interpretable representations indicates that this
technique is a potentially powerful tool for astronomical data mining.Comment: 12 Pages, 7 figures; accepted in SIAM 2005 International Conference
on Data Mining, Newport Beach, CA, April 200
Geosocial Graph-Based Community Detection
We apply spectral clustering and multislice modularity optimization to a Los
Angeles Police Department field interview card data set. To detect communities
(i.e., cohesive groups of vertices), we use both geographic and social
information about stops involving street gang members in the LAPD district of
Hollenbeck. We then compare the algorithmically detected communities with known
gang identifications and argue that discrepancies are due to sparsity of social
connections in the data as well as complex underlying sociological factors that
blur distinctions between communities.Comment: 5 pages, 4 figures Workshop paper for the IEEE International
Conference on Data Mining 2012: Workshop on Social Media Analysis and Minin
Utilizing Skylab data in on-going resources management programs in the state of Ohio
The author has identified the following significant results. The use of Skylab imagery for total area woodland surveys was found to be more accurate and cheaper than conventional surveys using aerial photo-plot techniques. Machine-aided (primarily density slicing) analyses of Skylab 190A and 190B color and infrared color photography demonstrated the feasibility of using such data for differentiating major timber classes including pines, hardwoods, mixed, cut, and brushland providing such analyses are made at scales of 1:24,000 and larger. Manual and machine-assisted image analysis indicated that spectral and spatial capabilities of Skylab EREP photography are adequate to distinguish most parameters of current, coal surface mining concern associated with: (1) active mining, (2) orphan lands, (3) reclaimed lands, and (4) active reclamation. Excellent results were achieved when comparing Skylab and aerial photographic interpretations of detailed surface mining features. Skylab photographs when combined with other data bases (e.g., census, agricultural land productivity, and transportation networks), provide a comprehensive, meaningful, and integrated view of major elements involved in the urbanization/encroachment process
PEPSI deep spectra. II. Gaia benchmark stars and other M-K standards
We provide a homogeneous library of high-resolution, high-S/N spectra for 48
bright AFGKM stars, some of them approaching the quality of solar-flux spectra.
Our sample includes the northern Gaia benchmark stars, some solar analogs, and
some other bright Morgan-Keenan (M-K) spectral standards. Well-exposed deep
spectra were created by average-combining individual exposures. The
data-reduction process relies on adaptive selection of parameters by using
statistical inference and robust estimators.We employed spectrum synthesis
techniques and statistics tools in order to characterize the spectra and give a
first quick look at some of the science cases possible. With an average
spectral resolution of R=220,000 (1.36 km/s), a continuous wavelength coverage
from 383 nm to 912 nm, and S/N of between 70:1 for the faintest star in the
extreme blue and 6,000:1 for the brightest star in the red, these spectra are
now made public for further data mining and analysis. Preliminary results
include new stellar parameters for 70 Vir and alpha Tau, the detection of the
rare-earth element dysprosium and the heavy elements uranium, thorium and
neodymium in several RGB stars, and the use of the 12C to 13C isotope ratio for
age-related determinations. We also found Arcturus to exhibit few-percent CaII
H&K and H-alpha residual profile changes with respect to the KPNO atlas taken
in 1999.Comment: in press, 15 pages, 7 figures, data available from pepsi.aip.d
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