7,658 research outputs found
LabelFusion: A Pipeline for Generating Ground Truth Labels for Real RGBD Data of Cluttered Scenes
Deep neural network (DNN) architectures have been shown to outperform
traditional pipelines for object segmentation and pose estimation using RGBD
data, but the performance of these DNN pipelines is directly tied to how
representative the training data is of the true data. Hence a key requirement
for employing these methods in practice is to have a large set of labeled data
for your specific robotic manipulation task, a requirement that is not
generally satisfied by existing datasets. In this paper we develop a pipeline
to rapidly generate high quality RGBD data with pixelwise labels and object
poses. We use an RGBD camera to collect video of a scene from multiple
viewpoints and leverage existing reconstruction techniques to produce a 3D
dense reconstruction. We label the 3D reconstruction using a human assisted
ICP-fitting of object meshes. By reprojecting the results of labeling the 3D
scene we can produce labels for each RGBD image of the scene. This pipeline
enabled us to collect over 1,000,000 labeled object instances in just a few
days. We use this dataset to answer questions related to how much training data
is required, and of what quality the data must be, to achieve high performance
from a DNN architecture
History, exploration, settlement and past use of the sub-Antarctic
Human impacts on the sub-Antarctic islands stem from sealing and whaling, alien species of plants and animals resulting from human incursions (both temporary and permanent), shipwrecks, settlements and weather stations arising from the Second World War, collecting by scientific expeditions, scientific stations and tourism. Many of these factors remain as important issues for the health and maintenance of the sub-Antarctic
Convex Optimization In Identification Of Stable Non-Linear State Space Models
A new framework for nonlinear system identification is presented in terms of
optimal fitting of stable nonlinear state space equations to input/output/state
data, with a performance objective defined as a measure of robustness of the
simulation error with respect to equation errors. Basic definitions and
analytical results are presented. The utility of the method is illustrated on a
simple simulation example as well as experimental recordings from a live
neuron.Comment: 9 pages, 2 figure, elaboration of same-title paper in 49th IEEE
Conference on Decision and Contro
Franck-Condon factors and observed band strength distribution in the vibrational structure of the Ag_2 D-X band system
Potential curves for the X_1Σ_g^+ and D_1Σ_u^+ states of three diatomic silver isotopomers, ^(107)Ag_2, ^(107)Ag^(109)Ag and ^(109)Ag_2, were determined from the best available molecular constants by the Rydberg-Klein-Rees method. From these potentials, Franck-Condon factors and band-origin wave numbers were computed, and the reliability of the obtained values was verified by comparison with the observed band strength distribution and the measured band origin positions in a previously recorded D-X spectrum. The ratios of the Franck-Condon factors to those of corresponding isotopic bands were found to be very close to unity, revealing only a very small isotopic effect on the Franck Condon factors of Ag_2 D-X bands. The isotopic shifts of the calculated band origins agree well with previously measured displacements of band heads
Development of a vortex generating flume for the removal of phosphorus from waste streams
Master of ScienceDepartment of Chemical EngineeringLarry A. GlasgowFeedlots, animal production facilities, and agricultural lands are point and non-point sources for nutrient enrichment of surrounding waterways and result in human enhanced eutrophication. Artificial elevation and increased enrichment from animal wastes, fertilizer, and runoff greatly increase the speed of this natural process and leads to degraded water quality, algae blooms, and fish kills. Phosphorous is typically the limiting nutrient for plant growth, and thus is the main focus of this paper. Phosphates enable excessive and choking plant growth that lead to depleted dissolved oxygen and excessive decaying plant matter, subsequently damaging the aquatic ecosystem.
In order to provide an inexpensive and feasible solution to minimize phosphate eutrophication, a passive, vortex generating flume has been proposed to provide the necessary mixing for the removal of phosphorus from waste waters. Preliminary tests with dye tracers and electrolyte pulse injections have been conducted to model the flow characteristics and determine the residence time under a variety of flow conditions, angle of inclination and flow rate.
The flume was modeled by two methods: four continuously stirred tank reactors (CSTRs) in series and as four CSTRs in series operating in parallel with a plug flow reactor (PFR). The hydraulic model fit a total of five parameters to the experimental data: Residence time, the inlet concentrations of the electrolyte pulse tracer, and the injection times of the tracer to both types of reactors.
The kinetic model was built based on data collected from a different study of swine lagoons using magnesium chloride to precipitate phosphorus as the mineral struvite. The precipitation kinetics were modeled using first order and irreversible reaction and incorporated into the hydraulic model. The vortex generating flume provided an operating space that sufficiently removed phosphorus from the waste stream. Future work will include pilot scale testing of the model using waste streams and the investigation of a scour to minimize solid formation in the flume
The Outer Halo of the Milky Way as Probed by RR Lyr Variables from the Palomar Transient Facility
RR Lyr stars are ideal massless tracers that can be used to study the total
mass and dark matter content of the outer halo of the Milky Way. This is
because they are easy to find in the light curve databases of large stellar
surveys and their distances can be determined with only knowledge of the light
curve. We present here a sample of 112 RR Lyr beyond 50 kpc in the outer halo
of the Milky Way, excluding the Sgr streams, for which we have obtained
moderate resolution spectra with Deimos on the Keck 2 Telescope. Four of these
have distances exceeding 100 kpc. These were selected from a much larger set of
447 candidate RR Lyr which were datamined using machine learning techniques
applied to the light curves of variable stars in the Palomar Transient Facility
database. The observed radial velocities taken at the phase of the variable
corresponding to the time of observation were converted to systemic radial
velocities in the Galactic standard of rest. From our sample of 112 RR Lyr we
determine the radial velocity dispersion in the outer halo of the Milky Way to
be ~90 km/s at 50 kpc falling to about 65 km/s near 100 kpc once a small number
of major outliers are removed. With reasonable estimates of the completeness of
our sample of 447 candidates and assuming a spherical halo, we find that the
stellar density in the outer halo declines as the -4 power of r.Comment: Accepted for publication in the Ap
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Cortisol levels in response to starting school in children at increased risk for social phobia
Background: Research on depression has identified hyperactivity of the HPA axis as a
potential contributory factor to the intergenerational transmission of affective symptoms. However,
this has not yet been examined in the context of social phobia. The current study compared HPA axis
activity in response to a universal social stressor (starting school) in children of 2 groups of women:
one with social phobia and one with no history of anxiety (comparison group). To determine specificity
of effects of maternal social phobia, a third group of children were also examined whose mothers had
generalised anxiety disorder (GAD).
Method: Children provided salivary cortisol samples in the morning, afternoon and at bedtime across 3
time-blocks surrounding the school start: a month before starting school (baseline), the first week at
school (stress response), and the end of the first school term (stress recovery). Child behavioural
inhibition at 14 months was also assessed to explore the influence of early temperament on later stress
responses.
Results: All children displayed an elevation in morning and afternoon cortisol from baseline during the
first week at school, which remained elevated until the end of the first term. Children in the social
phobia group, however, also displayed an equivalent elevation in bedtime cortisol, which was not
observed for comparison children or for children of mothers with GAD. Children in the social phobia
group who were classified as 'inhibited' at 14 months displayed significantly higher afternoon cortisol
levels overall.
Summary: A persistent stress response to school in the morning and afternoon is typical for all
children, but children of mothers with social phobia also display atypical elevations in evening cortisol
levels when at school - signalling long-term disruption of the circadian rhythm in HPA axis activity.
This is the first study to report HPA axis disruption in children at risk of developing social phobia, and
future research should aim to determine whether this represents a pathway for symptom
development, taking early temperament into account
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