2020
2020
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Record 13 of
Title:Precise temporal localization for complete actions with quantified temporal structure
Author(s):Lu, Chongkai(1); Li, Ruimin(2); Fu, Hong(3); Fu, Bin(2); Wang, Yihao(1); Lo, Wai-Lun(4); Chi, Zheru(1)Source: Proceedings - International Conference on Pattern Recognition Volume: Issue: DOI: 10.1109/ICPR48806.2021.9412081 Published: 2020Abstract:Existing temporal action detection algorithms cannot distinguish complete and incomplete actions while this property is essential in many applications. To tackle this challenge, we proposed the action progression networks (APN), a novel model that predicts action progression of video frames with continuous numbers. Using the progression sequence of test video, on the top of the APN, a complete action searching algorithm (CAS) was designed to detect complete actions only. With the usage of frame-level fine-grained temporal structure modeling and detecting actions according to their whole temporal context, our framework can locate actions precisely and is good at avoiding incomplete action detection. We evaluated our framework on a new dataset (DFMAD-70) collected by ourselves which contains both complete and incomplete actions. Our framework got good temporal localization results with 95.77% average precision when the IoU threshold is 0.5. On the benchmark THUMOS14, an incomplete-ignostic dataset, our framework still obtain competitive performance. ? 2020 IEEEAccession Number: 20212910659040 -
Record 14 of
Title:Proposal-based visual tracking using spatial cascaded transformed region proposal network
Author(s):Zhang, Ximing(1); Luo, Shujuan(2); Fan, Xuewu(1)Source: Sensors (Switzerland) Volume: 20 Issue: 17 DOI: 10.3390/s20174810 Published: September 1, 2020Abstract:Region proposal network (RPN) based trackers employ the classification and regression block to generate the proposals, the proposal that contains the highest similarity score is formulated to be the groundtruth candidate of next frame. However, region proposal network based trackers cannot make the best of the features from different convolutional layers, and the original loss function cannot alleviate the data imbalance issue of the training procedure. We propose the Spatial Cascaded Transformed RPN to combine the RPN and STN (spatial transformer network) together, in order to successfully obtain the proposals of high quality, which can simultaneously improves the robustness. The STN can transfer the spatial transformed features though different stages, which extends the spatial representation capability of such networks handling complex scenarios such as scale variation and affine transformation. We break the restriction though an easy samples penalization loss (shrinkage loss) instead of smooth L1 function. Moreover, we perform the multi-cue proposals re-ranking to guarantee the accuracy of the proposed tracker. We extensively prove the effectiveness of our proposed method on the ablation studies of the tracking datasets, which include OTB-2015 (Object Tracking Benchmark 2015), VOT-2018 (Visual Object Tracking 2018), LaSOT (Large Scale Single Object Tracking), TrackingNet (A Large-Scale Dataset and Benchmark for Object Tracking in the Wild) and UAV123 (UAV Tracking Dataset). ? 2020 by the authors. Licensee MDPI, Basel, Switzerland.Accession Number: 20203509110028 -
Record 15 of
Title:Research on safety self-perceptual optical payload of space vehicle
Author(s):Yingjun, Ma(1); Jianwei, Peng(1); Chao, Mei(1); Weining, Chen(1); Huinan, Guo(1)Source: Proceedings of SPIE - The International Society for Optical Engineering Volume: 11570 Issue: DOI: 10.1117/12.2576286 Published: 2020Abstract:Aiming at the threats to spacecraft safety caused by space debris, and improving the stability and working life of spacecraft in orbit, it is proposed to use spacecraft equipped with a safety self-perceptual optical payload to detect space debris to improve the safety of the aircraft in orbit. This paper analyses the application methods and characteristics of the safety self-perceptual optical payload of space vehicles, and defines the technical indicators of the optical payload. The safety self-Perceptual optical payload includes the MWIR optical system with large field of view and the visible continuous zoom lens with large zoom ratio. The detector resolution is 1280×1024, the pixel size is 15μm, the focal length is 8mm, the F number is 2, and the field of view is 97.6°×85° of MWIR optical system;The detector resolution is 1920×1080, the pixel size is 5.5μm, the focal length is 15mm~750mm, which has a 50 times zoom ratio, and the field of view is 38.8°×22.4°~0.80°×0.45° of the visible continuous zoom lens. The two systems are athermal designed in the temperature range of-40?~60? respectively to meet the environmental requirements of space applications. Safety self-perceptual optical payload could obtain, and apperceive long-range targets in the 10km range around the space vehicle, and improve the aircraft's survival ability. ? 2020 SPIE. All rights reserved.Accession Number: 20204909580499 -
Record 16 of
Title:Design of a high-resolution compact optical system applied to micro-nano satellites
Author(s):Qiao, Jiang(1); Wu, Cuigang(2)Source: Proceedings of SPIE - The International Society for Optical Engineering Volume: 11617 Issue: DOI: 10.1117/12.2585521 Published: 2020Abstract:In the field of space remote sensing technology, designing a long focal length, high resolution, compact optical imaging system is one of the current hotspots in the research of micro/nano satellites. Based on the general working lens structure and actual imaging requirements of micro/nano satellites, this paper uses paraxial imaging methods to analyze and calculate the various indicators of the lens. A high-resolution coaxial refractive optical system for space remote sensing satellites is designed. The system has the characteristics of long focal length, high resolution, and compact structure. Its working band is 380nm-780nm, focal length f is 1200mm, F/ # Is 6, the field of view angle can reach 2ω=1.4°. When the satellite orbit height is 420km and the sensor pixel size is 4.25μm, the geometries resolution GSD can reach 1.5m. Through multiple optimizations of the parameters, the final designed optical system has a full field of view MTF value greater than 0.28 at a spatial frequency of 188lp/mm, and the imaging effect is excellent, close to the diffraction limit. ? 2020 COPYRIGHT SPIE. Downloading of the abstract is permitted for personal use only.Accession Number: 20210109718762 -
Record 17 of
Title:Property of Nafion-ionic polymer-metal composites based on Mori–Tanaka methodology and gradient mechanics
Author(s):Yang, Liang(1); Zhang, Dongsheng(1); Zhang, Xining(1); Wang, Hong(2)Source: Applied Physics A: Materials Science and Processing Volume: 126 Issue: 8 DOI: 10.1007/s00339-020-03807-9 Published: August 1, 2020Abstract:Ionic polymer-metal composite (IPMC) actuators are a class of electroactive polymer composites that exhibit some interesting electromechanical characteristics such as low voltage actuation, large displacements, and benefit from low density and elastic modulus. Elastic modulus and surface resistance are basic properties of IPMCs that play a role in almost all practical applications of these materials. The prediction of the elastic modulus and surface resistance is of extreme importance to better grasp the mechanical behavior of IPMCs and to evaluate the success of the design. This paper has proposed a theoretical framework for predicting the elastic modulus and surface resistance of copper electrodes IPMCs. A five layers analytical assemblage model is introduced for the IPMCs relied upon improved classical lamination theory. The depositional metallic atoms were used as the exterior layer, the ionic polymer was used as the middle layer, and the material between the two layers was a gradient layer. Based on Mori–Tanaka methodology and gradient mechanics, the overall elastic properties of composites are obtained and lie between those obtained from the experiment. The prediction showed a good agreement with the experimental elastic modulus values with a maximum deviation of less than 10%. The overall results have provided useful insight into the elastic modulus and surface resistance effects to the properties of the IPMC. This would open further opportunities toward the higher application of IPMC. ? 2020, Springer-Verlag GmbH Germany, part of Springer Nature.Accession Number: 20203008971193 -
Record 18 of
Title:Olivine-norite rock detected by the lunar rover Yutu-2 likely crystallized from the SPA-impact melt pool
Author(s):Lin, Honglei(1); He, Zhiping(2); Yang, Wei(1); Lin, Yangting(1); Xu, Rui(2); Zhang, Chi(1); Zhu, Meng-Hua(3); Chang, Rui(1); Zhang, Jinhai(1); Li, Chunlai(2); Lin, Hongyu(4); Liu, Yang(5); Gou, Sheng(6); Wei, Yong(1); Hu, Sen(1); Xue, Changbin(7); Yang, Jianfeng(8); Zhong, Jie(9); Fu, Xiaohui(10); Wan, Weixing(1); Zou, Yongliao(5)Source: National Science Review Volume: 7 Issue: 5 DOI: 10.1093/nsr/nwz183 Published: April 17, 2020Abstract:Chang'E-4 landed in the South Pole-Aitken (SPA) basin, providing a unique chance to probe the composition of the lunar interior. Its landing site is located on ejecta strips in Von Kármán crater that possibly originate from the neighboring Finsen crater. A surface rock and the lunar regolith at 10 sites along the rover Yutu-2 track were measured by the onboard Visible and Near-Infrared Imaging Spectrometer in the first three lunar days of mission operations. In situ spectra of the regolith have peak band positions at 1 and 2 μm, similar to the spectral data of Finsen ejecta from the Moon Mineralogy Mapper, which confirms that the regolith's composition of the landing area is mostly similar to that of Finsen ejecta. The rock spectrum shows similar band peak positions, but stronger absorptions, suggesting relatively fresh exposure. The rock may consist of 38.1 ± 5.4% low-Ca pyroxene, 13.9 ± 5.1% olivine and 48.0 ± 3.1% plagioclase, referred to as olivine-norite. The plagioclase-abundant and olivine-poor modal composition of the rock is inconsistent with the origin of the mantle, but representative of the lunar lower crust. Alternatively, the rock crystallized from the impact-derived melt pool formed by the SPA-impact event via mixing the lunar crust and mantle materials. This scenario is consistent with fast-cooling thermal conditions of a shallow melt pool, indicated by the fine to medium-sized texture ( ? 2020 The Author(s) 2019. Published by Oxford University Press on behalf of China Science Publishing & Media Ltd.Accession Number: 20202608877341 -
Record 19 of
Title:Subspace Clustering Constrained Sparse NMF for Hyperspectral Unmixing
Author(s):Lu, Xiaoqiang(1); Dong, Le(1); Yuan, Yuan(2)Source: IEEE Transactions on Geoscience and Remote Sensing Volume: 58 Issue: 5 DOI: 10.1109/TGRS.2019.2946751 Published: May 2020Abstract:As one of the most important information of hyperspectral images (HSI), spatial information is usually simulated with the similarity among pixels to enhance the unmixing performance of nonnegative matrix factorization (NMF). Nevertheless, the similarity is generally calculated based on the Euclidean distance between pairwise pixels, which is sensitive to noise and fails in capturing subspace information of hyperspectral data. In addition, it is independent of the NMF framework. In this article, we propose a novel unmixing method called subspace clustering constrained sparse NMF (SC-NMF) for hyperspectral unmixing to more accurately extract endmembers and correspond abundances. First, the nonnegative subspace clustering is embedded into the NMF framework to learn a similar graph, which takes full advantage of the characteristics of the reconstructed data itself to extract the spatial correlation of pixels for unmixing. It is noteworthy that the similar graph and NMF will be simultaneously updated. Second, to mitigate the influence of noise in HSI, only the k largest values are retained in each self-expression vector. Finally, we use the idea of subspace clustering to extract endmembers by linearly combining of all pixels in spectral subspace, aiming at giving a reasonable physical significance to the endmembers. We evaluate the proposed SC-NMF on both synthetic and real hyperspectral data, and experimental results demonstrate that the proposed method is effective and superior by comparing with the state-of-The-Art methods. ? 1980-2012 IEEE.Accession Number: 20201908611383 -
Record 20 of
Title:Research on High Precision Permanent Magnet Servo Control System of Airborne Stable Platform
Author(s):Yu, Cao(1); Xiuqin, Su(2); Haitao, Wang(1); Meilin, Xie(1); Feng, Jing(1); Junfeng, Han(1); Peng, Liu(1)Source: Proceedings of 2020 IEEE 5th Information Technology and Mechatronics Engineering Conference, ITOEC 2020 Volume: Issue: DOI: 10.1109/ITOEC49072.2020.9141862 Published: June 2020Abstract:At present, airborne optoelectronic pod system develops rapidly and is widely used in military and civil fields. The stable platform control system is the key part of the photoelectric pod, which is used to isolate the disturbance of the body and the external environment, maintain the stability of the LOS and ensure the clear imaging of the sensor. In general, the model of airborne electro-optical stabilization platform can not be obtained accurately, and the characteristics of the system itself are affected by the external environment. At the same time, the noise interference such as torque and sensor actuator is also uncertain. In order to solve the above-mentioned uncertainty and improve the stability accuracy of the system, this paper takes the servo system of a two axis airborne photoelectric stability platform as the research object, uses SVPWM technology to complete the hardware and software design with DSP + FPGA as the control core, uses FOG and POS as speed and position sensors. And it aims at mechanical resonance, to design a digital notch filter to restrain it. Finally, the experiment shows that when the swing amplitude is 8.5°, frequency is 0.3Hz, the stability accuracy reaches 0.005° (3\sigma). The experiment shows that the stable platform control system has the advantages of fast response speed and high stability accuracy. ? 2020 IEEE.Accession Number: 20203809211625 -
Record 21 of
Title:What's Next for Key and Core Tech?
Author(s):Mi, Lei(1)Source: Innovation Volume: 1 Issue: 1 DOI: 10.1016/j.xinn.2020.04.015 Published: May 21, 2020Abstract:The Universe is a complicated network that evolved out of the Big Bang to the human-dominated world we see today. Technology is a collection of natural or scientific phenomena that have been discovered and used by human beings. The combination and evolution of technology is forming a complex, self-organizing, and evolving scale-free network. Originating from a technological system, key and core technology is the cornerstone to boosting economic and social progress. To develop a more sustainably focused planet, key and core technologies will play an increasingly vital role. ? 2020Accession Number: 20230813629867 -
Record 22 of
Title:Image acquisition and display system of AOTF polarization spectrometer
Author(s):Bu, Fan(1); Yao, Dalei(1); Qiu, Yuehong(1)Source: ACM International Conference Proceeding Series Volume: Issue: DOI: 10.1145/3443467.3444707 Published: November 6, 2020Abstract:AOTF (acousto-optic tunable filter)-based polarization spectroscopy imaging technology is an emerging cross-technical field. Exploring the application of this technology in military and civilian fields has become an important research topic at home and abroad. Compared with traditional instruments, AOTF polarization spectrometers have unique advantages in terms of working mechanism and instrument design. According to the working principle of AOTF and the working process of AOTF polarization spectrometer, an image acquisition and display technical scheme of polarizing spectrum imager based on the combination of AOTF and CCD camera is designed. In this paper, the host computer coded in VC++ is proposed to set some key parameters of CCD97-00 (EMCCD product of E2V Company) through USB2.0, such as exposure time, exposure interval, exposure gain and offset. Moreover, this system has single-frequency and continuous-sweep working modes under the control of the AOTF. After testing, the function of the system was verified. The results show that the system can efficiently and reliably collect polarized spectral image data and control corresponding instruments. It has certain research significance and practical value, and is providing large amount of image data for a follow-up study of polarized spectral images. ? 2020 ACM.Accession Number: 20210709909846 -
Record 23 of
Title:Image semantic segmentation based on high-resolution networks for monitoring agricultural vegetation
Author(s):Ganchenko, Valentin(1); Starovoitov, Valery(1); Zheng, Xiangtao(2)Source: Proceedings - 2020 22nd International Symposium on Symbolic and Numeric Algorithms for Scientific Computing, SYNASC 2020 Volume: Issue: DOI: 10.1109/SYNASC51798.2020.00050 Published: September 2020Abstract:In the article, recognition of state of agricultural vegetation from aerial photographs at various spatial resolutions was considered. Proposed approach is based on a semantic segmentation using convolutional neural networks. Two variants of High-Resolution network architecture (HRNet) are described and used. These neural networks were trained and applied to aerial images of agricultural fields. In our experiments, accuracy of four land classes recognition (soil, healthy vegetation, diseased vegetation and other objects) was about 93-94%. ? 2020 IEEE.Accession Number: 20211110079773 -
Record 24 of
Title:Diverse rock types detected in the lunar south pole-aitken basin by the Chang'E-4 lunar mission
Author(s):Huang, Jun(1,2); Xiao, Zhiyong(2,3,4); Xiao, Long(1,2,4); Horgan, Briony(5); Hu, Xiaoyi(1); Lucey, Paul(6); Xiao, Xiao(1); Zhao, Siyuan(1); Qian, Yuqi(1); Zhang, Hao(1); Li, Chunlai(7); Xu, Rui(7); He, Zhiping(7); Yang, Jianfeng(8); Xue, Bin(8); He, Qi(1); Zhong, Jie(9); Lin, Hongyu(10); Huang, Changning(10); Xie, Jianfeng(11)Source: Geology Volume: 48 Issue: 7 DOI: 10.1130/G47280.1 Published: 2020Abstract:The South Pole-Aitken (SPA) basin, located between the South Pole and Aitken crater on the far side of the Moon, is the largest confirmed lunar impact structure. The pre-Nectarian SPA basin is a 2400 x 2050 km elliptical structure centered at 53°S, 191°E, which should have exposed lower crust and upper mantle due to the enormous excavation depth. Olivine, the dominant mineral in Earth's mantle, has only been identified in small and localized exposures in the margins of the SPA basin, and the dominant mafic component is, instead, pyroxene. These mineralogical characteristics could be explained by the recent hypothesis that the lunar upper mantle is dominated by low-calcium pyroxene, not olivine. Here, we present observations from imaging and spectral data from China's Chang'E-4 (CE-4) lunar mission in the first 4 synodic days, especially the first in situ visible/near-infrared spectrometer observations of an exposed boulder. We identified a variety of rock types, but not the recently reported olivine-rich materials in the landing region. The results are consistent with orbital observations. The obtained mineralogical information provides a better understanding of the nature and origin of SPA materials. ? 2020 Geological Society of America.Accession Number: 20203309042055