68 research outputs found
LocPoseNet: Robust Location Prior for Unseen Object Pose Estimation
Object location priors have been shown to be critical for the standard 6D
object pose estimation setting, where the training and testing objects are the
same. Specifically, they can be used to initialize the 3D object translation
and facilitate 3D object rotation estimation. Unfortunately, the object
detectors that are used for this purpose do not generalize to unseen objects,
i.e., objects from new categories at test time. Therefore, existing 6D pose
estimation methods for previously-unseen objects either assume the ground-truth
object location to be known, or yield inaccurate results when it is
unavailable. In this paper, we address this problem by developing a method,
LocPoseNet, able to robustly learn location prior for unseen objects. Our
method builds upon a template matching strategy, where we propose to distribute
the reference kernels and convolve them with a query to efficiently compute
multi-scale correlations. We then introduce a novel translation estimator,
which decouples scale-aware and scale-robust features to predict different
object location parameters. Our method outperforms existing works by a large
margin on LINEMOD and GenMOP. We further construct a challenging synthetic
dataset, which allows us to highlight the better robustness of our method to
various noise sources
Recommended from our members
Down-regulation of the M6P/IGF-II receptor increases cell proliferation and reduces apoptosis in neonatal rat cardiac myocytes
BACKGROUND: The mannose 6-phosphate/insulin-like growth factor-II receptor (M6P/IGF2R) is a multi-functional protein that has been implicated in regulation of cell growth and apoptosis. Cardiac myocytes express relatively high levels of M6P/IGF2R, and cardiomyocyte apoptosis has been identified in a variety of cardiovascular disorders, such as myocardial infarction and heart failure. However, involvement of M6P/IGF2R in the pathogenesis of these conditions has not been determined. Thus, the objective of this study was to determine the role of M6P/IGF2R in regulation of cardiac myocyte growth and apoptosis. RESULTS: We down-regulated the expression of M6P/IGF2R in neonatal rat cardiac myocytes and examined the effect on cell proliferation and apoptosis. Infection of neonatal cardiomyocytes with an adenovirus expressing a ribozyme targeted against the M6P/IGF2R significantly reduced the level of M6P/IGF2R mRNA, as determined by RT-PCR and Ribonuclease Protection Assay (RPA). M6P-containing protein binding and endocytosis as well as the M6P/IGF2R-mediated internalization of (125)I-IGF-II were lower in the ribozyme-treated cells than the control myocytes, indicating that the number of functional M6P/IGF2R in the ribozyme treated cells was reduced. Accordingly, a marked increase in cell proliferation and a reduced cell susceptibility to hypoxia- and TNF-induced apoptosis were observed in the ribozyme-treated cells. CONCLUSIONS: These findings suggest that M6P/IGF2R may play a role in regulation of cardiac myocyte growth and apoptosis. Down regulation of this gene in cardiac tissues might be a new approach to prevention of cell death or promotion of mitogenesis for certain heart diseases
Effects of coarse-graining on the scaling behavior of long-range correlated and anti-correlated signals
We investigate how various coarse-graining methods affect the scaling
properties of long-range power-law correlated and anti-correlated signals,
quantified by the detrended fluctuation analysis. Specifically, for
coarse-graining in the magnitude of a signal, we consider (i) the Floor, (ii)
the Symmetry and (iii) the Centro-Symmetry coarse-graining methods. We find,
that for anti-correlated signals coarse-graining in the magnitude leads to a
crossover to random behavior at large scales, and that with increasing the
width of the coarse-graining partition interval this crossover moves
to intermediate and small scales. In contrast, the scaling of positively
correlated signals is less affected by the coarse-graining, with no observable
changes when a crossover appears at small
scales and moves to intermediate and large scales with increasing . For
very rough coarse-graining () based on the Floor and Symmetry
methods, the position of the crossover stabilizes, in contrast to the
Centro-Symmetry method where the crossover continuously moves across scales and
leads to a random behavior at all scales, thus indicating a much stronger
effect of the Centro-Symmetry compared to the Floor and the Symmetry methods.
For coarse-graining in time, where data points are averaged in non-overlapping
time windows, we find that the scaling for both anti-correlated and positively
correlated signals is practically preserved. The results of our simulations are
useful for the correct interpretation of the correlation and scaling properties
of symbolic sequences.Comment: 19 pages, 13 figure
Construction of C-C bonds via photoreductive coupling of ketones and aldehydes in the metal-organic-framework MFM-300(Cr).
From Europe PMC via Jisc Publications RouterHistory: ppub 2021-06-01, epub 2021-06-11Publication status: PublishedFunder: RCUK | Engineering and Physical Sciences Research Council (EPSRC); Grant(s): EP/I011870Funder: European Research Council; Grant(s): 742401Construction of C-C bonds via reductive coupling of aldehydes and ketones is hindered by the highly negative reduction potential of these carbonyl substrates, particularly ketones, and this renders the formation of ketyl radicals extremely endergonic. Here, we report the efficient activation of carbonyl compounds by the formation of specific host-guest interactions in a hydroxyl-decorated porous photocatalyst. MFM-300(Cr) exhibits a band gap of 1.75âeV and shows excellent catalytic activity and stability towards the photoreductive coupling of 30 different aldehydes and ketones to the corresponding 1,2-diols at room temperature. Synchrotron X-ray diffraction and electron paramagnetic resonance spectroscopy confirm the generation of ketyl radicals via confinement within MFM-300(Cr). This protocol removes simultaneously the need for a precious metal-based photocatalyst or for amine-based sacrificial agents for the photochemical synthesis
Efficient photocatalytic reduction of CO2 catalyzed by the metalâorganic framework MFM-300(Ga)
Photocatalytic reduction of CO2 to carbon fuels is an important target but highly challenging to achieve. Here, we report the efficient photoconversion of CO2 into formic acid over a Ga(III)-based metalâorganic framework (MOF) material using triethanolamine as the sacrificial agent. Under light irradiation and at room temperature, photoreduction of CO2 over MFM-300(Ga) yields formic acid with a selectivity of 100%, a high productivity of 502 ± 18 ÎŒmol·gcatâ1·hâ1, and excellent catalytic stability. In situ electron paramagnetic resonance spectroscopy reveals that MFM-300(Ga) promotes the generation of CO2âąâ radical anions as a reaction intermediate driven by strong binding and activation of CO2 molecules at the bridging âOH sites within the pore. This study represents the first example of a Ga(III)-based MOF catalyst for CO2 reduction
Modulation of uptake and reactivity of nitrogen dioxide in metalâorganic framework materials
We report the modulation of reactivity of nitrogen dioxide (NO2) in a charged metalâorganic framework (MOF) material, MFMâ305âCH3 in which unbound Nâcentres are methylated and the cationic charge counterâbalanced by Clâ ions in the pores. Uptake of NO2 into MFMâ305âCH3 leads to reaction between NO2 and Clâ to give nitrosyl chloride (NOCl) and NO3â anions. A high dynamic uptake of 6.58 mmol gâ1 at 298 K is observed for MFMâ305âCH3 as measured using a flow of 500 ppm NO2 in He. In contrast, the analogous neutral material, MFMâ305, shows a much lower uptake of 2.38 mmol gâ1. The binding domains and reactivity of adsorbed NO2 molecules within MFMâ305âCH3 and MFMâ305 have been probed using in situ synchrotron Xâray diffraction, inelastic neutron scattering and by electron paramagnetic resonance, highâfield solidâstate nuclear magnetic resonance and UV/Vis spectroscopies. The design of charged porous sorbents provides a new platform to control the reactivity of corrosive air pollutants
Fusing Local Similarities for Retrieval-based 3D Orientation Estimation of Unseen Objects
In this paper, we tackle the task of estimating the 3D orientation of
previously-unseen objects from monocular images. This task contrasts with the
one considered by most existing deep learning methods which typically assume
that the testing objects have been observed during training. To handle the
unseen objects, we follow a retrieval-based strategy and prevent the network
from learning object-specific features by computing multi-scale local
similarities between the query image and synthetically-generated reference
images. We then introduce an adaptive fusion module that robustly aggregates
the local similarities into a global similarity score of pairwise images.
Furthermore, we speed up the retrieval process by developing a fast retrieval
strategy. Our experiments on the LineMOD, LineMOD-Occluded, and T-LESS datasets
show that our method yields a significantly better generalization to unseen
objects than previous works. Our code and pre-trained models are available at
https://sailor-z.github.io/projects/Unseen_Object_Pose.html.Comment: Accepted by ECCV 202
- âŠ