3,176 research outputs found
Jumble Java Byte Code to Measure the Effectiveness of Unit Tests
Jumble is a byte code level mutation testing tool for Java which inter-operates with JUnit. It has been designed to operate in an industrial setting with large projects. Heuristics have been included to speed the checking of mutations, for example, noting which test fails for each mutation and running this first in subsequent mutation checks. Significant effort has been put into ensuring that it can test code which uses custom class loading and reflection. This requires careful attention to class path handling and coexistence with foreign class-loaders. Jumble is currently used on a continuous basis within an agile programming environment with approximately 370,000 lines of Java code under source control. This checks out project code every fifteen minutes and runs an incremental set of unit tests and mutation tests for modified classes. Jumble is being made available as open source
Aerial applications dispersal systems control requirements study
Performance deficiencies in aerial liquid and dry dispersal systems are identified. Five control system concepts are explored: (1) end of field on/off control; (2) manual control of particle size and application rate from the aircraft; (3) manual control of deposit rate on the field; (4) automatic alarm and shut-off control; and (5) fully automatic control. Operational aspects of the concepts and specifications for improved control configurations are discussed in detail. A research plan to provide the technology needed to develop the proposed improvements is presented along with a flight program to verify the benefits achieved
Faecal haemoglobin can define risk of colorectal neoplasia at surveillance colonoscopy in patients at increased risk of colorectal cancer.
SDSS IV MaNGA - Rotation Velocity Lags in the Extraplanar Ionized Gas from MaNGA Observations of Edge-on Galaxies
We present a study of the kinematics of the extraplanar ionized gas around
several dozen galaxies observed by the Mapping of Nearby Galaxies at the Apache
Point Observatory (MaNGA) survey. We considered a sample of 67 edge-on galaxies
out of more than 1400 extragalactic targets observed by MaNGA, in which we
found 25 galaxies (or 37%) with regular lagging of the rotation curve at large
distances from the galactic midplane. We model the observed emission
velocity fields in the galaxies, taking projection effects and a simple model
for the dust extinction into the account. We show that the vertical lag of the
rotation curve is necessary in the modeling, and estimate the lag amplitude in
the galaxies. We find no correlation between the lag and the star formation
rate in the galaxies. At the same time, we report a correlation between the lag
and the galactic stellar mass, central stellar velocity dispersion, and axial
ratio of the light distribution. These correlations suggest a possible higher
ratio of infalling-to-local gas in early-type disk galaxies or a connection
between lags and the possible presence of hot gaseous halos, which may be more
prevalent in more massive galaxies. These results again demonstrate that
observations of extraplanar gas can serve as a potential probe for accretion of
gas.Comment: 13 pages, 11 figures, accepted for publication in Ap
Elementary amenable subgroups of R. Thompson's group F
The subgroup structure of Thompson's group F is not yet fully understood. The
group F is a subgroup of the group PL(I) of orientation preserving, piecewise
linear self homeomorphisms of the unit interval and this larger group thus also
has a poorly understood subgroup structure. It is reasonable to guess that F is
the "only" subgroup of PL(I) that is not elementary amenable. In this paper, we
explore the complexity of the elementary amenable subgroups of F in an attempt
to understand the boundary between the elementary amenable subgroups and the
non-elementary amenable. We construct an example of an elementary amenable
subgroup up to class (height) omega squared, where omega is the first infinite
ordinal.Comment: 20 page
Handwritten digit recognition by bio-inspired hierarchical networks
The human brain processes information showing learning and prediction
abilities but the underlying neuronal mechanisms still remain unknown.
Recently, many studies prove that neuronal networks are able of both
generalizations and associations of sensory inputs. In this paper, following a
set of neurophysiological evidences, we propose a learning framework with a
strong biological plausibility that mimics prominent functions of cortical
circuitries. We developed the Inductive Conceptual Network (ICN), that is a
hierarchical bio-inspired network, able to learn invariant patterns by
Variable-order Markov Models implemented in its nodes. The outputs of the
top-most node of ICN hierarchy, representing the highest input generalization,
allow for automatic classification of inputs. We found that the ICN clusterized
MNIST images with an error of 5.73% and USPS images with an error of 12.56%
9.7 um Silicate Features in AGNs: New Insights into Unification Models
We describe observations of 9.7 um silicate features in 97 AGNs, exhibiting a
wide range of AGN types and of X-ray extinction toward the central nuclei. We
find that the strength of the silicate feature correlates with the HI column
density estimated from fitting the X-ray data, such that low HI columns
correspond to silicate emission while high columns correspond to silicate
absorption. The behavior is generally consistent with unification models where
the large diversity in AGN properties is caused by viewing-angle-dependent
obscuration of the nucleus. Radio-loud AGNs and radio-quiet quasars follow
roughly the correlation between HI columns and the strength of the silicate
feature defined by Seyfert galaxies. The agreement among AGN types suggests a
high-level unification with similar characteristics for the structure of the
obscuring material. We demonstrate the implications for unification models
qualitatively with a conceptual disk model. The model includes an inner
accretion disk (< 0.1 pc in radius), a middle disk (0.1-10 pc in radius) with a
dense diffuse component and with embedded denser clouds, and an outer clumpy
disk (10-300 pc in radius).Comment: Accepted for publication in ApJ, 14 pages, 5 figures. The on-line
table is available at http://cztsy.as.arizona.edu/~yong/silicate_tab1.pd
Reconfiguration on sparse graphs
A vertex-subset graph problem Q defines which subsets of the vertices of an
input graph are feasible solutions. A reconfiguration variant of a
vertex-subset problem asks, given two feasible solutions S and T of size k,
whether it is possible to transform S into T by a sequence of vertex additions
and deletions such that each intermediate set is also a feasible solution of
size bounded by k. We study reconfiguration variants of two classical
vertex-subset problems, namely Independent Set and Dominating Set. We denote
the former by ISR and the latter by DSR. Both ISR and DSR are PSPACE-complete
on graphs of bounded bandwidth and W[1]-hard parameterized by k on general
graphs. We show that ISR is fixed-parameter tractable parameterized by k when
the input graph is of bounded degeneracy or nowhere-dense. As a corollary, we
answer positively an open question concerning the parameterized complexity of
the problem on graphs of bounded treewidth. Moreover, our techniques generalize
recent results showing that ISR is fixed-parameter tractable on planar graphs
and graphs of bounded degree. For DSR, we show the problem fixed-parameter
tractable parameterized by k when the input graph does not contain large
bicliques, a class of graphs which includes graphs of bounded degeneracy and
nowhere-dense graphs
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