Tanks and temples Knapitsch, Arno; Park, Jaesik; Zhou, Qian-Yi ...
ACM transactions on graphics,
08/2017, Volume:
36, Issue:
4
Journal Article
Peer reviewed
We present a benchmark for image-based 3D reconstruction. The benchmark sequences were acquired outside the lab, in realistic conditions. Ground-truth data was captured using an industrial laser ...scanner. The benchmark includes both outdoor scenes and indoor environments. High-resolution video sequences are provided as input, supporting the development of novel pipelines that take advantage of video input to increase reconstruction fidelity. We report the performance of many image-based 3D reconstruction pipelines on the new benchmark. The results point to exciting challenges and opportunities for future work.
Solid polymer electrolytes (SPEs) have aroused wide interest in lithium batteries because of their sufficient mechanical properties, superior safety performances, and excellent processability. ...However, ionic conductivity and high‐voltage compatibility of SPEs are still yet to meet the requirement of future energy‐storage systems, representing significant barriers to progress. In this regard, intermolecular interactions in SPEs have attracted attention, and they can significantly impact on the Li+ motion and frontier orbital energy level of SPEs. Recent advances in improving electrochemcial performance of SPEs are reviewed, and the underlying mechanism of these proposed strategies related to intermolecular interaction is discussed, including ion–dipole, hydrogen bonds, π–π stacking, and Lewis acid–base interactions. It is hoped that this review can inspire a deeper consideration on this critical issue, which can pave new pathway to improve ionic conductivity and high‐voltage performance of SPEs.
Intermolecular interactions, including ion–dipole, hydrogen bonds, π–π stacking, and Lewis acid–base interactions, significantly impact on Li+ motion and high‐voltage compatibility of solid polymer electrolytes. The effect and underlying mechanism of intermolecular interactions on electrochemcial performance are discussed, aiming to provide a new concept for the development of high‐energy‐density solid lithium batteries.
We present a global optimization approach for mapping color images onto geometric reconstructions. Range and color videos produced by consumer-grade RGB-D cameras suffer from noise and optical ...distortions, which impede accurate mapping of the acquired color data to the reconstructed geometry. Our approach addresses these sources of error by optimizing camera poses in tandem with non-rigid correction functions for all images. All parameters are optimized jointly to maximize the photometric consistency of the reconstructed mapping. We show that this optimization can be performed efficiently by an alternating optimization algorithm that interleaves analytical updates of the color map with decoupled parameter updates for all images. Experimental results demonstrate that our approach substantially improves color mapping fidelity.
DNA damage is the dominant source of mutation, which is the driving force of evolution. Therefore, it is important to quantitatively analyze the DNA damage caused by different mutagenesis methods, ...the subsequent mutation rates, and their relationship. Atmospheric and room temperature plasma (ARTP) mutagenesis has been used for the mutation breeding of more than 40 microorganisms. However, ARTP mutagenesis has not been quantitatively compared with conventional mutation methods. In this study, the umu test using a flow-cytometric analysis was developed to quantify the DNA damage in individual viable cells using Salmonella typhimurium NM2009 as the model strain and to determine the mutation rate. The newly developed method was used to evaluate four different mutagenesis systems: a new ARTP tool, ultraviolet radiation, 4-nitroquinoline-1-oxide (4-NQO), and N-methyl-N’-nitro-N-nitrosoguanidine (MNNG) mutagenesis. The mutation rate was proportional to the corresponding SOS response induced by DNA damage. ARTP caused greater DNA damage to individual living cells than the other conventional mutagenesis methods, and the mutation rate was also higher. By quantitatively comparing the DNA damage and consequent mutation rate after different types of mutagenesis, we have shown that ARTP is a potentially powerful mutagenesis tool with which to improve the characteristics of microbial cell factories.
We present an approach to detailed reconstruction of complex real-world scenes with a handheld commodity range sensor. The user moves the sensor freely through the environment and images the scene. ...An offline registration and integration pipeline produces a detailed scene model. To deal with the complex sensor trajectories required to produce detailed reconstructions with a consumer-grade sensor, our pipeline detects points of interest in the scene and preserves detailed geometry around them while a global optimization distributes residual registration errors through the environment. Our results demonstrate that detailed reconstructions of complex scenes can be obtained with a consumer-grade camera.
Colored Point Cloud Registration Revisited Jaesik Park; Qian-Yi Zhou; Koltun, Vladlen
2017 IEEE International Conference on Computer Vision (ICCV),
2017-Oct.
Conference Proceeding
We present an algorithm for aligning two colored point clouds. The key idea is to optimize a joint photometric and geometric objective that locks the alignment along both the normal direction and the ...tangent plane. We extend a photometric objective for aligning RGB-D images to point clouds, by locally parameterizing the point cloud with a virtual camera. Experiments demonstrate that our algorithm is more accurate and more robust than prior point cloud registration algorithms, including those that utilize color information. We use the presented algorithms to enhance a state-of-the-art scene reconstruction system. The precision of the resulting system is demonstrated on real-world scenes with accurate ground-truth models.
Microplastic polystyrene foam has been found widely in the environment and is readily transported by wind or water. Beached and virgin foams of size 0.45–1 mm were prepared as sorbents to study ...oxytetracycline sorption. Enhanced adsorption were found in the beached foams compared to the virgin foams, corresponding to the higher specific surface area, micropore area and the degree of oxidation of the former. The Freundlich Kf value was 894 ± 84 ((mg kg−1) (mg L−1)1/n) for oxytetracycline adsorption on the beached foams, approximately twice as high as on the virgin foams. Effects of solution pH on adsorption to the beached foams were more pronounced to the virgin foams. Maximum adsorption occurred at pH 5 at which electrostatic repulsion between the microplastic surface and the oxytetracycline zwitterion was minimal, indicating that electrostatic interaction may have regulated adsorption. Moreover, H-bonding and multivalent cationic bridging mechanisms may also have affected the adsorption of oxytetracycline to the beached foams as reflected by the ionic effects. Adsorption was promoted more in the presence of humic acid than of fulvic acid, perhaps owing to π-π conjugation between the humic acid and the microplastic surface which led to enhanced electrostatic attraction for oxytetracycline. This study suggests that weathered polystyrene foams may act as carriers of antibiotics in the environment and their potential risks to ecosystem and human health merit further investigation.
Display omitted
•Beached microplastics had greater hydrophilic functional groups on its surface.•Beached and virgin foams had different adsorption mechanism for oxytetracycline.•Oxytetracylcine had maximal sorption to the beached microplastics as zwitterion.•More promotion of oxytetracylcine sorption affected by humic acid than fulvic acid.
Beached polystyrene foams had enhanced affinity for oxytetracycline adsorption owing to their oxidized surfaces.
Aflatoxin B1 (AFB1) monitoring has attracted extensive attention because food safety is a worldwide public health problem. Herein, we design a novel simultaneously visual and photoelectrochemical ...(PEC) immunosensing system for rapid sensitive detection of AFB1 in foodstuff. The immunoreaction was carried out on anti-AFB1 antibody-modified magnetic beads by using glucose oxidase (GOx)-labeled AFB1-bovine serum albumin (AFB1–BSA) conjugates as the tags with a competitive-type immunoassay format, while the visual and PEC evaluation was performed via carbon quantum dots (CQDs)-functionalized MnO2 nanosheets. Accompanying the formation of immunocomplexes, the carried GOx initially oxidized the substrate (glucose) for the generation of H2O2, which reduced/etched MnO2 nanosheets into Mn2+ ions, thereby resulting in the dissociation of CQDs from the electrode. Within the applied potentials, the photocurrent of MnO2-CQDs-modified electrode decreased with the increasing H2O2 level in the detection cell. Meanwhile, a visual detection could be performed according to the change in the color of MnO2-CQDs-coated electrode. To elaborate, this system was aggregated into a high-throughput microfluidic device to construct a semiautomatic detection cell. Under optimal conditions, the photocurrent increased with the increasing target AFB1 within a dynamic working range from 0.01 to 20 ng mL–1 with a limit of detection (LOD) of 2.1 pg mL–1 (ppt). The developed immunoassay exhibited good reproducibility and acceptable accuracy. In addition, the method accuracy relative to AFB1 ELISA kit was evaluated for analyzing naturally contaminated or spiked peanut samples, giving the well-matched results between two methods. Although our strategy was focused on the detection of target AFB1, it is easily extended to screen other small molecules or mycotoxins, thereby representing a versatile immunosensing scheme.
Learning Compact Geometric Features Khoury, Marc; Qian-Yi Zhou; Koltun, Vladlen
2017 IEEE International Conference on Computer Vision (ICCV),
2017-Oct.
Conference Proceeding
Open access
We present an approach to learning features that represent the local geometry around a point in an unstructured point cloud. Such features play a central role in geometric registration, which ...supports diverse applications in robotics and 3D vision. Current state-of-the-art local features for unstructured point clouds have been manually crafted and none combines the desirable properties of precision, compactness, and robustness. We show that features with these properties can be learned from data, by optimizing deep networks that map high-dimensional histograms into low-dimensional Euclidean spaces. The presented approach yields a family of features, parameterized by dimension, that are both more compact and more accurate than existing descriptors.
Robust reconstruction of indoor scenes Sungjoon Choi; Qian-Yi Zhou; Koltun, Vladlen
2015 IEEE Conference on Computer Vision and Pattern Recognition (CVPR),
06/2015
Conference Proceeding
Open access
We present an approach to indoor scene reconstruction from RGB-D video. The key idea is to combine geometric registration of scene fragments with robust global optimization based on line processes. ...Geometric registration is error-prone due to sensor noise, which leads to aliasing of geometric detail and inability to disambiguate different surfaces in the scene. The presented optimization approach disables erroneous geometric alignments even when they significantly outnumber correct ones. Experimental results demonstrate that the presented approach substantially increases the accuracy of reconstructed scene models.
PDF
