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基于特征点改进的视觉SLAM定位研究

计算机测量与控制 2024年第2期32卷 219-226页

作者：王伟汤琴琴汪先伟南京信息工程大学自动化学院南京210000 无锡学院轨道交通学院江苏无锡214000

为改善视觉SLAM系统在低纹理环境下定位精度较低的现象,提出一种改进的ORB特征点提取策略和一种关键帧选择机制;首先采用多尺度分析和基于局部灰度的特征检测方法克服一般ORB算法缺乏尺度和旋转描述的缺点;其次提出一种基于高斯模糊的... 详细信息

为改善视觉SLAM系统在低纹理环境下定位精度较低的现象,提出一种改进的ORB特征点提取策略和一种关键帧选择机制;首先采用多尺度分析和基于局部灰度的特征检测方法克服一般ORB算法缺乏尺度和旋转描述的缺点;其次提出一种基于高斯模糊的图像信息增强方法解决传统ORB特征点提取方法在纹理信息不被突出环境下容易失效的问题,并对图像进行象限分割使特征点均匀分布;最后为剔除劣质关键帧,设计了一种综合时间因素与特征点数量因素的关键帧选择机制;将提出的方法移植到ORB_SLAM2上,并在TUM数据集上测试,实验结果表明,视觉SLAM系统的定位误差平均降低14.688%,证实了该方法的有效性。

关键词：视觉SLAM 低纹理特征点关键帧定位

Numerical Simulation for Shallow Strata Stability of Coral Reef in the Southwest of Yongshu Reef(South China Sea)

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Journal of Ocean University of China 2018年第4期17卷 763-772页

作者： tang qinqin ZHANG Jinchang FENG Yingci LI Jian YAO Yantao SUN Jie ZHAN Wenhuan Key Laboratory of Ocean and Marginal Sea Geology CASGuangzhou 510301China University of Chinese Academy of Sciences Beijing 100049China

In recent years, infrastructure construction on coral reefs has been increasingly developed. Therefore, the shallow strata stability of coral reefs in the South China Sea should be evaluated. This study aims to investigate the profiles for the shallow strata of coral reefs in the southwest of the Yongshu Reef, particularly in the hydrodynamic marine environment, and to establish a geological model for numerical simulation using Geo-Studio. The shallow strata of the coral reefs include mass gravel, sand gravel, mid-coarse sand, silty sand, fine sand, and reef limestone. The shallow reef slope near the lagoon is similar to a ‘layer cake', in which the side close to the sea is analogous to a ‘block cake'. The simulation results showed that coral reef stability depends on wave loads and earthquake strength and on the physical properties of coral reefs. The factor of safety for the outer reef is greater than 10.0 under static, wave, and seismic conditions; this indicated that the outer reefs were less affected by waves and earthquakes. However, the factor of safety next to the lagoon varied from 0.1 to 5.3. The variation was primarily caused by the thick strata of coral reefs close to the sea(reef limestone, typically with the thickness > 10 m and equivalent to a block). The soil and rock layers in the coral reef strata with thicknesses < 10 m showed weak engineering geological characteristics. Our findings can provide useful information to future construction projects on coral reefs.

关键词： coral reefs rock mass structure stability evaluation numerical simulation

Dynamic computation offloading in time-varying environment for ultra-dense networks:a stochastic game approach

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The Journal of China Universities of Posts and Telecommunications 2021年第2期28卷 24-37页

作者： Xie Renchao Liu Xu Duan Xuefei tang qinqin Yu Fei Richard Huang Tao State Key Laboratory of Networking and Switching Technology Beijing University of Posts and TelecommunicationsBeijing 100876China Guangdong Communications and Networks Institute Guangzhou 510700China Department of Future Networks Purple Mountain LaboratoryNanjing 211111China Department of Systems and Computer Engineering Carleton UniversityOttawaCanada

To meet the demands of large-scale user access with computation-intensive and delay-sensitive applications,combining ultra-dense networks(UDNs)and mobile edge computing(MEC)are considered as important *** the MEC enabled UDNs,one of the most important issues is computation *** a number of work have been done toward this issue,the problem of dynamic computation offloading in time-varying environment,especially the dynamic computation offloading problem for multi-user,has not been fully ***,in order to fill this gap,the dynamic computation offloading problem in time-varying environment for multi-user is considered in this *** considering the dynamic changes of channel state and users’queue state,the dynamic computation offloading problem for multi-user is formulated as a stochastic game,which aims to optimize the delay and packet loss rate of *** find the optimal solution of the formulated optimization problem,Nash Q-learning(NQLN)algorithm is proposed which can be quickly converged to a Nash equilibrium ***,extensive simulation results are presented to demonstrate the superiority of NQLN *** is shown that NQLN algorithm has better optimization performance than the benchmark schemes.

关键词： dynamic computation offloading time-varying environment stochastic game ultra-dense networks(UDNs) mobile edge computing(MEC)

Boosting genome editing in plants with single transcript unit surrogate reporter systems

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Plant Communications 2024年第6期5卷 32-43页

作者： Xu tang Qiurong Ren Xiaodan Yan Rui Zhang Li Liu qinqin Han Xuelian Zheng Yiping Qi Hongyuan Song Yong Zhang Chongqing Key Laboratory of Plant Resource Conservation and Germplasm Innovation Integrative Science Center of Germplasm Creation in Western China(Chongqing)Science CitySchool of Life SciencesSouthwest UniversityChongqing 400715China Key Laboratory of Agricultural Biosafety and Green Production of Upper Yangtze River Ministry of EducationChongqing 400715China College of Horticulture and Landscape Architecture Southwest UniversityChongqing 400715China Department of Biotechnology School of Life Sciences and TechnologyCenter for Informational BiologyUniversity of Electronic Science and Technology of ChinaChengdu 610054China School of Synbiology School of Life ScienceShanxi UniversityTaiyuan 030006China Department of Plant Science and Landscape Architecture University of MarylandCollege ParkMD 20742USA Institute for Bioscience and Biotechnology Research University of MarylandRockvilleMD 20850USA

CRISPR-Cas-based genome editing holds immense promise for advancing plant genomics and crop ***,the challenge of low editing activity complicates the identification of editing *** this study,we introduce multiple single transcript unit surrogate reporter(STU-SR)systems to enhance the selection of genome-edited *** systems use the same single guide RNAs designed for endogenous genes to edit reporter genes,establishing a direct link between reporter gene editing activity and that of endogenous *** strategies are used to restore functional reporter genes after genome editing,including efficient single-strand annealing(SSA)for homologous recombination in STUSR-SSA ***-SR-base editor systems leverage base editing to reinstate the start codon,enriching C-to-T and A-to-G base editing *** results showcase the effectiveness of these STU-SR systems in enhancing genome editing events in the monocot rice,encompassing Cas9 nuclease-based targeted mutagenesis,cytosine base editing,and adenine base *** systems exhibit compatibility with Cas9 variants,such as the PAM-less SpRY,and are shown to boost genome editing in Brassica oleracea,a dicot vegetable *** summary,we have developed highly efficient and versatile STU-SR systems for enrichment of genome-edited plants.

关键词： CRISPR-Cas9 single transcript unit STU surrogate reporter SR single strand annealing SSA cyto-sine base editing adenine base editing

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川崎病治疗新进展

临床儿科杂志 2013年第5期31卷 488-490页

作者：唐琴琴余唯琪兰州大学第一医院小儿内科甘肃兰州730000

川崎病(KD)是一种急性全身性血管炎症,主要见于婴儿及5岁以下儿童。冠状动脉损伤(CAL)是其最严重并发症,在未治疗患儿中发生率20%～25%,即使经大剂量静脉用丙种球蛋白(intravenous immunoglobulin,IVIG)及阿司匹林的积极治疗CAL的发生... 详细信息

川崎病(KD)是一种急性全身性血管炎症,主要见于婴儿及5岁以下儿童。冠状动脉损伤(CAL)是其最严重并发症,在未治疗患儿中发生率20%～25%,即使经大剂量静脉用丙种球蛋白(intravenous immunoglobulin,IVIG)及阿司匹林的积极治疗CAL的发生率仍可达5%～6%。大剂量IVIG(2 g/kg)是KD急性期治疗的金标准,但有近8%～38%的KD患儿对IVIG抵抗,导致CAL风险增加。大剂量阿司匹林并不能预防CAL的发生。近年来,也有些新的治疗如英夫利昔单克隆抗体、阿昔单抗、甲基泼尼松龙冲击、血浆置换、细胞毒类药物等应用于IVIG无反应性KD。

关键词：川崎病丙种球蛋白冠状动脉瘤治疗

Harboring CAR-T cells using an injectable scaffold to treat solid tumors

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National Science Review 2024年第5期11卷 91-92页

作者： Li tang Institute of Bioengineering (IBI) école polytechnique fédérale de Lausanne (EPFL)

Genetic expression of chimeric antigen receptors (CAR) enables T cells to target and kill cancer cells in an MHCindependent manner, resulting in a potent antitumor response [1]. To date, more than 10 CAR-T cell products have been approved globally for the treatment of hematologic disorders such as relapsed/refractory B-cell acute lymphoblastic leukemia, non-Hodgkin lymphoma, and multiple myeloma [2,3].

关键词： IMMUNOTHERAPY CANCER

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南海东部古扩张脊的俯冲机制

海洋地质与第四纪地质 2017年第6期37卷 1-11页

作者：詹文欢李健唐琴琴中国科学院边缘海与大洋地质重点实验室中国科学院南海海洋研究所广州510301 中国科学院大学北京100049

南海东部古扩张脊处于欧亚板块和太平洋板块的汇聚地带,其东侧为马尼拉海沟、北吕宋海槽和西吕宋海槽,由于受到多个构造单元的相互作用,使其处于复杂的构造环境中。南海东部古扩张脊俯冲过程的研究对深入理解南海海盆构造演化、火山及... 详细信息

南海东部古扩张脊处于欧亚板块和太平洋板块的汇聚地带,其东侧为马尼拉海沟、北吕宋海槽和西吕宋海槽,由于受到多个构造单元的相互作用,使其处于复杂的构造环境中。南海东部古扩张脊俯冲过程的研究对深入理解南海海盆构造演化、火山及地震活动等具有重要意义,同时也是今后南海构造研究的重要方向之一。在总结前人研究基础之上,探讨南海东部古扩张脊俯冲时间、俯冲深度及动力学过程。南海板块在16 Ma之后,由于菲律宾板块NW向仰冲的作用,使南海东部古扩张脊被动地沿马尼拉海沟进行俯冲,形成了现今马尼拉海沟中段的构造格局。古扩张脊俯冲深度为200~300km,并且在约100km处发生板片撕裂,造成古扩张脊两侧俯冲角度的不同。

关键词：古扩张脊俯冲带马尼拉海沟南海

Topologically protected entanglement switching around exceptional points

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Light(Science & Applications) 2024年第8期13卷 1631-1644页

作者： Zan tang Tian Chen Xing tang Xiangdong Zhang Key Laboratory of Advanced Optoelectronic Quantum Architecture and Measurements of Ministry of Education Beijing Key Laboratory of Nanophotonics&Ultrafine Optoelectronic SystemsSchool of PhysicsBeijing Institute of Technology100081 BeijingChina

The robust operation of quantum entanglement states is crucial for applications in quantum information,computing,and communications^(1–3).However,it has always been a great challenge to complete such a task because of decoherence and ***,we propose theoretically and demonstrate experimentally an effective scheme to realize robust operation of quantum entanglement states by designing quadruple degeneracy exceptional *** encircling the exceptional points on two overlapping Riemann energy surfaces,we have realized a chiral switch for entangled states with high *** to the topological protection conferred by the Riemann surface structure,this switching of chirality exhibits strong robustness against perturbations in the encircling ***,we have experimentally validated such a scheme on a quantum walk *** work opens up a new way for the application of non-Hermitian physics in the field of quantum information.

关键词： exceptional quantum Riemann

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基于图优化的激光惯导紧耦合SLAM研究

电子测量技术 2023年第1期46卷 35-42页

作者：郑川川柯福阳汤琴琴南京信息工程大学自动化学院南京210000 南京信息工程大学遥感与测绘学院南京210000 无锡学院轨道交通学院无锡214000 南京信息工程大学无锡研究院无锡214000

现有的激光惯导里程计大多采用滤波的松耦合融合方法,在大场景建图中会存在一定的运动估计漂移,导致定位与建图精度降低。针对这一问题提出了一种基于图优化的激光惯导紧耦合里程计与建图方法。在前端依次进行点云畸变补偿、点云聚类分... 详细信息

现有的激光惯导里程计大多采用滤波的松耦合融合方法,在大场景建图中会存在一定的运动估计漂移,导致定位与建图精度降低。针对这一问题提出了一种基于图优化的激光惯导紧耦合里程计与建图方法。在前端依次进行点云畸变补偿、点云聚类分割、地面与特征提取。在后端采用图优化方法融合IMU预积分、激光里程计和回环检测信息完成地图构建。最后利用Kitti数据集和自采集数据对LOAM、LeGO-LOAM和本文方法在里程计精度和回环检测效果上进行了对比分析。实验结果表明本文方法在定位与建图精度上相比于LOAM和LeGO-LOAM分别提高了45%和35%以上,有着更优的鲁棒性。

关键词：激光惯导图优化紧耦合定位与建图