66 research outputs found
A Method for Pose and Type Verification of Resistor
AbstractThis paper proposes a method for verifying the pose and the type of different resistors mounted on a PCB. First, the pose of the resistor on the PCB is determined and missing resistors are detected by shape_based template matching. Then, the type of the resistor is extracted and compared to the known reference type by edge_based template matching. Finally, six types of resistors have been verified on 120 resistor images. Experiments have shown that the shape_based template can be used to determine the pose of the resistor even if it appears rotated and scaled. The proposed method can achieve the accuracy of 100% and average recognition time of 0.15s
ProgressLabeller: Visual Data Stream Annotation for Training Object-Centric 3D Perception
Visual perception tasks often require vast amounts of labelled data,
including 3D poses and image space segmentation masks. The process of creating
such training data sets can prove difficult or time-intensive to scale up to
efficacy for general use. Consider the task of pose estimation for rigid
objects. Deep neural network based approaches have shown good performance when
trained on large, public datasets. However, adapting these networks for other
novel objects, or fine-tuning existing models for different environments,
requires significant time investment to generate newly labelled instances.
Towards this end, we propose ProgressLabeller as a method for more efficiently
generating large amounts of 6D pose training data from color images sequences
for custom scenes in a scalable manner. ProgressLabeller is intended to also
support transparent or translucent objects, for which the previous methods
based on depth dense reconstruction will fail. We demonstrate the effectiveness
of ProgressLabeller by rapidly create a dataset of over 1M samples with which
we fine-tune a state-of-the-art pose estimation network in order to markedly
improve the downstream robotic grasp success rates. ProgressLabeller is
open-source at https://github.com/huijieZH/ProgressLabeller.Comment: IROS 2022 accepted paper; project page:
https://progress.eecs.umich.edu/projects/progress-labeller
Probing the dipole portal to heavy neutral leptons via meson decays at the high-luminosity LHC
We consider the dipole portal to sterile neutrinos, also called heavy neutral
leptons (HNLs). The dipole interaction with the photon leads to HNL production
in meson decays, as well as triggers the HNL decay into an active neutrino and
a photon. HNLs with masses of order of 0.01-1 GeV are naturally long-lived if
the dipole coupling is sufficiently small. We perform Monte-Carlo simulations
and derive the sensitivities of the proposed FASER2 and FACET long-lived
particle experiments to HNLs produced via the dipole operator in meson decays
at the high-luminosity LHC. Our findings show that these future detectors will
be complementary to each other, as well as to existing experiments, and will be
able to probe new parts of the parameter space, especially in the case of the
dipole operator coupled to the tau neutrino.Comment: 16 pages+refs, 5 figures, 2 table
TransNet: Transparent Object Manipulation Through Category-Level Pose Estimation
Transparent objects present multiple distinct challenges to visual perception
systems. First, their lack of distinguishing visual features makes transparent
objects harder to detect and localize than opaque objects. Even humans find
certain transparent surfaces with little specular reflection or refraction,
like glass doors, difficult to perceive. A second challenge is that depth
sensors typically used for opaque object perception cannot obtain accurate
depth measurements on transparent surfaces due to their unique reflective
properties. Stemming from these challenges, we observe that transparent object
instances within the same category, such as cups, look more similar to each
other than to ordinary opaque objects of that same category. Given this
observation, the present paper explores the possibility of category-level
transparent object pose estimation rather than instance-level pose estimation.
We propose \textit{\textbf{TransNet}}, a two-stage pipeline that estimates
category-level transparent object pose using localized depth completion and
surface normal estimation. TransNet is evaluated in terms of pose estimation
accuracy on a large-scale transparent object dataset and compared to a
state-of-the-art category-level pose estimation approach. Results from this
comparison demonstrate that TransNet achieves improved pose estimation accuracy
on transparent objects. Moreover, we use TransNet to build an autonomous
transparent object manipulation system for robotic pick-and-place and pouring
tasks
Biological Monitoring of Cadmium Exposed Workers in a Nickel-Cadmium Battery Factory in China
Abstract: Biological Monitoring of Cadmium Exposed Workers in a Nickel-Cadmium Battery Factory in China: Guicheng ZHANG, et al. School of Public Health, Curtin University of Technology-A cross-sectional study of renal damage in workers from a Chinese Ni-Cd battery factory is reported in this paper. The present exposure of surveyed workers to Cd may be likened to that of factories in developed countries prior to the 1950s. The results show urinary cadmium did not increase significantly with the years of exposure in aged workers exposed to cadmium. In these occupationally exposed workers urinary cadmium levels of 3 to 60 µg/g creatinine relate to between 15% and 20% of the workers having B 2 -MG proteinura, and blood cadmium levels less than 5 µg/l relate to more than 10% of the workers having B 2 -MG proteinura. The results suggest that a urinary cadmium concentration of 5 µg/g cr or a blood cadmium concentration of 5 µg/ l would not be a safe level. (J Occup Health 2002; 44: 15-21
Learning to Select Cuts for Efficient Mixed-Integer Programming
Cutting plane methods play a significant role in modern solvers for tackling
mixed-integer programming (MIP) problems. Proper selection of cuts would remove
infeasible solutions in the early stage, thus largely reducing the
computational burden without hurting the solution accuracy. However, the major
cut selection approaches heavily rely on heuristics, which strongly depend on
the specific problem at hand and thus limit their generalization capability. In
this paper, we propose a data-driven and generalizable cut selection approach,
named Cut Ranking, in the settings of multiple instance learning. To measure
the quality of the candidate cuts, a scoring function, which takes the
instance-specific cut features as inputs, is trained and applied in cut ranking
and selection. In order to evaluate our method, we conduct extensive
experiments on both synthetic datasets and real-world datasets. Compared with
commonly used heuristics for cut selection, the learning-based policy has shown
to be more effective, and is capable of generalizing over multiple problems
with different properties. Cut Ranking has been deployed in an industrial
solver for large-scale MIPs. In the online A/B testing of the product planning
problems with more than variables and constraints daily, Cut Ranking has
achieved the average speedup ratio of 12.42% over the production solver without
any accuracy loss of solution.Comment: Paper accepted at Pattern Recognition journa
The Last Strike: Evaluating the Distortionary Effect of Career Incentives on Taxation in China
Holographic stability and storage capacity on bulk green-light sensitive TI/PMMA materials
An emerging cationic photo-initiator titanocene (TI) dispersed poly (methyl methacrylate) (PMMA) photopolymer was fabricated by an optimized three-step thermo-polymerization method with excellent holographic performances. Materials with different thicknesses (1-3 mm) were prepared and characterized experimentally. The influences of material thickness changes on holographic properties have been investigated in detail. We achieved the response time of 4.98s in 1mm TI/PMMAs, while the cumulative gratings strength of 6.88 and single grating diffraction efficiency of 74% in 3 mm ones. Furthermore, gratings recorded in materials were examined with controlling experimental conditions in a green-light two-beam coupling interference system, under different polarization directions, ambient temperatures and intersection angles, respectively. A better holographic recording condition was proposed. Meanwhile, the influence on recording surroundings for TI/PMMA were analyzed. This work can provide a basis to depict the holographic storage capacity and stability in TI/PMMA polymers
Small Incision Lenticule Extraction (SMILE) versus Femtosecond Laser-Assisted In Situ Keratomileusis (FS-LASIK) for Myopia: A Systematic Review and Meta-Analysis.
The goal of this study was to compare small incision lenticule extraction (SMILE) with femtosecond laser-assisted in situ keratomileusis (FS-LASIK) for treating myopia.The CENTRAL, EMBASE, PubMed databases and a Chinese database (SinoMed) were searched in May of 2016. Twelve studies with 1,076 eyes, which included three randomized controlled trials (RCTs) and nine cohorts, met our inclusion criteria. The overall quality of evidence was evaluated using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) working group framework. Data were extracted and analysed at three to six months postoperatively. Primary outcome measures included a loss of one or more lines of best spectacle corrected visual acuity (BSCVA), uncorrected visual acuity (UCVA) of 20/20 or better, mean logMAR UCVA, postoperative mean spherical equivalent (SE) and postoperative refraction within ±1.0 D of the target refraction. Secondary outcome measures included ocular surface disease index (OSDI), tear breakup time (TBUT) and Schirmer's 1 test (S1T) as dry eye parameters, along with corneal sensitivity.The overall quality of evidence was considered to be low to very low. Pooled results revealed no significant differences between the two groups with regard to a loss of one or more lines in the BSCVA (OR 1.71; 95% CI: 0.81, 3.63; P = 0.16), UCVA of 20/20 or better (OR 0.71; 95% CI: 0.44, 1.15; P = 0.16), logMAR UCVA (MD 0.00; 95% CI: -0.03, 0.04; P = 0.87), postoperative refractive SE (MD -0.00; 95% CI: -0.05, 0.05; P = 0.97) or postoperative refraction within ±1.0 D of the target refraction (OR 0.78; 95% CI: 0.22, 2.77; P = 0.70) within six months postoperatively. The pooled analysis also indicated that the FS-LASIK group suffered more severely from dry eye symptoms (OSDI; MD -6.68; 95% CI: -11.76, -2.00; P = 0.006) and lower corneal sensitivity (MD 12.40; 95% CI: 10.23, 14.56; P < 0.00001) at six months postoperatively.In conclusion, both FS-LASIK and SMILE are safe, effective and predictable surgical options for treating myopia. However, dry eye symptoms and loss of corneal sensitivity may occur less frequently after SMILE than after FS-LASIK
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