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Status of UnDifferenced and Uncombined GNSS Data Processing Activities in China

Journal of Geodesy and Geoinformation science 2023年第3期6卷 135-144页

作者： Pengyu HOU Delu CHE Teng LIU Jiuping ZHA Yunbin YUAN Baocheng ZHANG State Key Laboratory of Geodesy and Earth’s Dynamics Innovation Academy for Precision Measurement Science and TechnologyChinese Academy of SciencesWuhan 430077China College of Earth and Planetary Sciences University of Chinese Academy of SciencesBeijing 100049China (German)International Science and Technology Cooperative Offshore Center for Geodesy Frontier Technology Wuhan 430077China Guangzhou Urban Planning&Design Survey Research Institute Guangzhou 510060China

With the continued development of multiple Global Navigation Satellite Systems(GNSS)and the emergence of various frequencies,UnDifferenced and UnCombined(UDUC)data processing has become an increasingly attractive *** this contribution,we provide an overview of the current status of UDUC GNSS data processing activities in *** activities encompass the formulation of Precise Point Positioning(PPP)models and PPP-Real-Time Kinematic(PPP-RTK)models for processing single-station and multi-station GNSS data,*** single-station data processing,we discuss the advancements in PPP models,particularly the extension from a single system to multiple systems,and from dual frequencies to single and multiple ***,we introduce the modified PPP model,which accounts for the time variation of receiver code biases,a departure from the conventional PPP model that typically assumes these biases to be *** the realm of multi-station PPP-RTK data processing,we introduce the ionosphere-weighted PPP-RTK model,which enhances the model strength by considering the spatial correlation of ionospheric *** also review the phase-only PPP-RTK model,designed to mitigate the impact of unmodelled code-related ***,we explore GLONASS PPP-RTK,achieved through the application of the integer-estimable *** large-scale network data processing,we introduce the all-in-view PPP-RTK model,which alleviates the strict common-view requirement at all ***,we present the decentralized PPP-RTK data processing strategy,designed to improve computational ***,this work highlights the various advancements in UDUC GNSS data processing,providing insights into the state-of-the-art techniques employed in China to achieve precise GNSS applications.

关键词： Global Navigation Satellite Systems(GNSS) UnDifferenced and UnCombined(UDUC) Precise Point Positioning(PPP) PPP-Real-Time Kinematic(PPP-RTK) single-station data processing multi-station data processing

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Pressure Field Reconstruction with PIV Experimental Velocity Field inside Falling Liquid Film 20

Pressure Field Reconstruction with PIV Experimental Velocity...

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20th International Topical Meeting on Nuclear reactor Thermal Hydraulics, NURETH 2023

作者： Wang, Ruiqi Duan, Riqiang Zou, Zhenhai Huang, Chonghai Wang, Chenyang Li, Bangming Science and Technology on Thermal Energy and Power Laboratory Hubei Wuhan430205 China Wuhan Second Ship Design and Research Institute Hubei Wuhan430205 China Institute of Nuclear and New Energy Technology Tsinghua University Beijing100084 China

ISBN: (纸本)9780894487934

In order to establish the pressure field inside falling liquid films, and to provide gradient of flow field inside films for surface wave evolution analysis. Pressure reconstruction based on PIV results was performed with Poisson equation method for pressure field inside falling liquid films, the pressure reconstruction method is verified with Rankine Vortex and Impinging Jet by comparing constructed pressure field and theoretical pressure field. Pressure field inside film was deduced with the verified pressure field construction method, and flow reversal mechanism was analyzed based on the pressure field and PIV velocity field. © 2023 Proceedings of the 20th International Topical Meeting on Nuclear reactor Thermal Hydraulics, NURETH 2023. All rights reserved.

关键词： Poisson equation

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High-Precision Point Cloud Data Acquisition for Robot Based on Multiple Constraints 16th

High-Precision Point Cloud Data Acquisition for Robot Based ...

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16th International Conference on Intelligent Robotics and Applications, ICIRA 2023

作者： Li, Bingbing Zhang, Teng Sun, Hao Deng, Runpeng Peng, Fangyu Yan, Rong Tang, Xiaowei The National NC System Engineering Research Center School of Mechanical Science and Engineering Huazhong University of Science and Technology Wuhan430074 China The Wuhan Digital Design and Manufacturing Innovation Center Co. Ltd. Wuhan430074 China The State Key Laboratory of Digital Manufacturing Equipment and Technology School of Mechanical Science and Engineering Huazhong University of Science and Technology Wuhan430074 China

ISBN: (纸本)9789819964796

The foundation of high-precision 3D reconstruction is the acquisition of high-precision point clouds. Through multi-view point cloud scanning and alignment, the point cloud of parts can be obtained. The great flexibility of the robot enables it to carry out scanning operations that require multi-view. However, the robots are limited in position error, and the accuracy of the camera varies depending on the range of vision. In addition, the point cloud density is influenced by the curvature of the workpiece, which seriously limits the accuracy of point cloud acquisition and registration. To solve these problems, a method of high-precision point cloud data acquisition for robots based on multiple constraints is proposed. The precision of the measuring system is increased by imposing constraints. So the high-performance field of vision of the camera and the high-performance motion space of the robot are obtained. The effect of workpiece curvature on point cloud scanning is thought to require increased camera viewpoints. After obtaining the camera viewpoints, the moving route planning of the robot is implemented using the ant colony voting method. In this paper, a curved blade experiment was carried out to prove the advantages of our method. It is not necessary for the point cloud overlap rate or the parts with many features. The accuracy of scanned point clouds is 0.249 mm, which is less than the results of using intelligent algorithms and marked points. © The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2023.

关键词： Cameras

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Highly Stereoselective C-Glycosylation by Photocatalytic Decarboxylative Alkynylation on Anomeric Position:A Facile Access to Alkynyl C-Glycosides

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Chinese Journal of Chemistry 2022年第6期40卷 681-686页

作者： Kailin Lu Yingying Ma Shihui Liu Shixun Guo Yongqiang Zhang Shanghai Frontiers Science Center of Optogenetic Techniques for Cell Metabolism Shanghai Key Laboratory of New Drug DesignSchool of PharmacyEast China University of Science and TechnologyShanghai 200237China College of Medicine Jiaxing UniversityJiaxingZhejiang 314001China

The highly stereoselective synthesis of diverse medicinally valuable alkynyl C-glycosides under mild and green reaction conditions remains a great ***,we wish to report a visible-light induced photocatalytic decarboxylative alkynylation *** utilizing an iridium photocatalyst in the presence of visible light,glycosyl radicals are in-situ generated via the decarboxylation of anomeric acids and efficiently coupled with a variety of ethynylbenziodoxolones(EBXs),which allows the facile synthesis of a variety of alkynyl C-glycosides in moderate to high yields and with excellent diastereoselectivity.

关键词： Photocatalysis Anomeric position Decarboxylative alkynylation C-C coupling Glycosides

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Gradient-index curved acoustic lenses for high-precision imaging 4

Gradient-index curved acoustic lenses for high-precision ima...

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4th International Computational Imaging Conference, CITA 2024

作者： Zhang, Lei Li, Wei Liu, Zeru Zhang, Min Lian, Meng Cao, Tun School of Optoelectronic Engineering and Instrument Science Dalian University of Technology Dalian116024 China National Key Laboratory of Electromagnetic Information Control and Effects Shenyang110036 China Shenyang Aircraft Design and Research Institute Shenyang110036 China

ISBN: (纸本)9781510688834

Acoustic lens is widely used in ultrasound imaging to manipulate the focusing of sound beams. In this paper, a three-dimensional gradient-index multifunctional lens based on circuit control is proposed. Different from the previous acoustic lens based on phonon crystal or crimp-space design, the lens is easy to manufacture and only depends on the refractive index tunable material to fill the lens structure. Based on multiple variable refractive index of this article Einstein ring RineHart curved shell structure, building material and refractive index of the mapping relation of shell structure, electrically induced regulation method of refractive index is put forward, make the surface acoustic wave propagation in a three-dimensional curved surface lens effect and its propagation in 2 d plane lens effect, instead of being placed in the surface concave and convex lens interference of objects. Several strange acoustic phenomena, such as invisibility cloak, Luneburg lens and Fisheye Lens, have been realized by simulation. By adjusting the gradient distribution of refractive index of the lens electrically, acoustic devices with different functional waveforms can be switched. The research results provide theoretical guidance for the design of a new type of multifunctional lens. © 2025 SPIE.

关键词： Ultrasonic imaging

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Unveiling the geometric site dependent activity of spinel Co_(3)O_(4)for electrocatalytic chlorine evolution reaction

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Journal of Energy Chemistry 2024年第5期92卷 95-103页

作者： Linke Cai Yao Liu Jingfang Zhang Qiqi Jia Jiacheng Guan Hongwei Sun Yu Yu Yi Huang Key Laboratory of Pesticide&Chemical Biology of Ministry of Education Engineering Research Center of Photoenergy Utilization for Pollution Control and Carbon Reduction of Ministry of EducationCollege of ChemistryCentral China Normal UniversityWuhan 430079HubeiChina Key Laboratory of Green Chemical Engineering Process of Ministry of Education Engineering Research Center of Phosphorus Resources Development and Utilization of Ministry of EducationHubei Key Laboratory of Novel Reactor and Green Chemical TechnologySchool of Chemical Engineering&PharmacyWuhan Institute of TechnologyWuhan 430205HubeiChina College of Materials Science and Engineering Fuzhou UniversityFuzhou 350108FujianChina School of Chemistry and Chemical Engineering Anhui UniversityHefei 230601AnhuiChina

Spinel cobalt oxide(Co_(3)O_(4)),consisting of tetrahedral Co^(2+)(CoTd)and octahedral Co^(3+)(CoOh),is considered as promising earth-abundant electrocatalyst for chlorine evolution reaction(CER).Identifying the catalytic contribution of geometric Co site in the electrocatalytic CER plays a pivotal role to precisely modulate electronic configuration of active Co sites to boost ***,combining density functional theory calculations and experiment results assisted with operando analysis,we found that the Co_(Oh) site acts as the main active site for CER in spinel Co_(3)O_(4),which shows better Cl^(-)adsorption and more moderate intermediate adsorption toward CER than CoTd site,and does not undergo redox transition under CER condition at applied *** by above findings,the oxygen vacancies were further introduced into the Co_(3)O_(4) to precisely manipulate the electronic configuration of Co_(Oh) to boost Cl^(-)adsorption and optimize the reaction path of CER and thus to enhance the intrinsic CER activity *** work figures out the importance of geometric configuration dependent CER activity,shedding light on the rational design of advanced electrocatalysts from geometric configuration optimization at the atomic level.

关键词： Chlorine evolution reaction Geometry effects Active chlorine Electronic configuration optimization Spinel oxides

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Calculating detonation performance of explosives by VLWR thermodynamics code introduced with universal VINET equation of state

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Defence technology（防务技术） 2022年第6期18卷 1041-1051页

作者： Qin Liu Ying-liang Duan Wei Cao Hong-hao Ma Xin-ping Long Yong Han Institute of Chemical Materials China Academy of Engineering PhysicsYouxian Ditrict621000Mianyang CitySichuan ProvinceChina CAS Key Laboratory of Mechanical Behavior and Design of Materials Department of Modern MechanicsSchool of Engineering ScienceUniversity ofScience and Technology of ChinaHefeiAnhui230026PR China China Academy of Engineering Physics Youxian Distnict621000Mianyang CitySichuan ProvinceChina Key Laboratory of Fire Science University of Science and Technology of ChinaHefeiAnhui230026PR China

Thermodynamic calculation is the theoretical basis for the study of initiation and detonation,as well as the prerequisite for forecasting the detonation performance of unknown *** on the VLWR(Virial-Wu)thermodynamic code,this paper introduced the universal solid equation of state(EOS)*** order to truly reflect the compressibility of nanocarbon under the extremely high-temperature and high-pressure environment in detonation,an SVM(support vector machine)was utilized to optimize the input parameters of *** detonation performance of several explosives with different densities was calculated by the optimized universal EOS,and the results show that the thermodynamic code coupled with the universal solid EOS VINET can predict the detonation performance parameters of explosives *** investigate the application of the thermodynamic code with the improved VINET EOS in the working capacity of explosives,the interrelationship between pressure P-particle velocity u and pressure P-volume V were computed for the detonation products of TNT and HMX-based PBX(HMX:binder:insensitive agent=95:4.3:0.7)in the CJ isentropic state.A universal curve proposed by Cooper was used to compared the computed isentropic state,where the ratio of pressure to CJ state were plotted against the ratio of velocity to CJ *** parameters of the JWL(Jones-Wilkins-Lee)EOS for detonation products were obtained by fitting the P-V *** cylinder tests of TNT and HMX-based PBX were numerically simulated using the LS-DYNA,it is verified that,within a certain range,the improved algorithm has superiority in describing the working capacity of explosives.

关键词： Detonation performance Thermodynamic calculation VINET equation of state VLWR thermodynamics Code Support vector machine Cylinder test

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Simulation Study of Filling Conditions for Aircraft Fire Suppression Systems

Simulation Study of Filling Conditions for Aircraft Fire Sup...

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2022 CSAA/IET International Conference on Aircraft Utility Systems, AUS 2022

作者： Yuan, Changyu Wang, Yameng Li, Haofan Dai, Chaoqi Lu, Song Zhang, Heping State Key Laboratory of Fire Science University of Science and Technology of China Hefei China Shenyang Airplane Design & Res Inst Shenyang China

ISBN: (数字)9781839537769

ISBN: (纸本)9781839537769

Based on the two-phase flow theory and the Peng-Robinson equation, a mathematical model of an airplane fire extinguishing system is propoesed. The flow characteristics of the extinguishing system under different filling pressures and initial temperatures were studied. It is found that at 5.75 kg of agent charge, the filling pressure can influence the discharge rate of bottle, and this effect decreases with increasing pressure. The emptying time, storage rate and mass flow rate of the nozzle at 4, 5 and 6 MPa pressures are close to each other, and the fire extinguishing system with a filling pressure of 6 MPa releases all Halon 1301 into the target compartment when 1.035 s. The initial temperature had a small effect on the discharge efficiency of the system, with the temperature at which the airplane was cruising being the least favorable for agent discharge. The flow rate at each nozzle is strongly influenced by the initial temperature. The initial temperature affects the in-tube distribution of Halon 1301, where only about 12 % of Halon 1301 is emitted from nozzles 3 and 4, and this value may decrease to 3.6% as the initial temperature decreases. © 2022 IET Conference Proceedings. All rights reserved.

关键词： Aircraft

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Security Enhancing for IRS-Aided NOMA Networks via Constructive Interference Precoding 10

Security Enhancing for IRS-Aided NOMA Networks via Construct...

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10th IEEE International Symposium on Microwave, Antenna, Propagation and EMC Technologies for Wireless Communications, MAPE 2024

作者： Bao, Jingying Cao, Yang Qin, Xiaoqi Xu, Lexi Zhao, Nan Niyato, Dusit School of Information and Communication Engineering Dalian University of Technology Dalian116024 China Singapore University of Technology and Design Engineering Systems and Design Pillar Singapore487372 Singapore Beijing University of Posts and Telecommunications State Key Laboratory of Networking and Switching Technology Beijing100876 China Research Institute China United Network Communications Corporation Beijing100048 China College of Computing and Data Science Nanyang Technological University Singapore639798 Singapore

ISBN: (纸本)9798331533922

In this paper, we propose a constructive interference precoding (CIP) enabled secure intelligent reflecting surface (IRS)-non-orthogonal multiple access (NOMA) scheme, lever-aging both the inter-user interference and artificial noise to boost the legitimate transmission of far user, while inducing the eavesdropper to decode the deceptive information. Based on this CIP-NOMA scheme, we minimize the transmit power under the perfect channel state information (CSI), subject to the CIP constraint for the far user and eavesdropper, while guaranteeing the quality of service and successive interference cancellation for the near user and the IRS unit modulus constraint. To handle this non-convex problem, an alternating optimization algorithm is proposed. Specifically, by alternately optimizing the precoding vectors at the base station and the IRS reflecting matrix via the successive convex approximation and the penalty-based algorithm, respectively, a reliable solution can be obtained. Simulation results demonstrate that the proposed scheme can achieve better security performance with less energy consumption compared to the conventional NOMA. © 2024 IEEE.

关键词： Multiple access interference

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SLSNet: Weakly-Supervised Skin Lesion Segmentation Network with Self-attentions 20th

SLSNet: Weakly-Supervised Skin Lesion Segmentation Network w...

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20th Pacific Rim International Conference on Artificial Intelligence, PRICAI 2023

作者： Pei, Songwen Huang, Junjie School of Optical-Electrical and Computer Engineering University of Shanghai for Science and Technology Shanghai200093 China State Key Laboratory of Computer Architecture Institute of Computing Technology Chinese Academy of Sciences Beijing100190 China Engineering Research Center of Software/Hardware Co-design Technology and Application Ministry of Education East China Normal University Shanghai200062 China

ISBN: (纸本)9789819970247

Computer-aided skin lesion segmentation with high precision is crucial to diagnose skin cancers in the early stage. However, the lack of pixel-level labels makes the skin lesion segmentation tasks challenging. To tackle this problem, a new weakly-supervised skin lesion segmentation network with self-attentions named SLSNet is proposed. SLSNet contains two modules and uses image-level labels as supervision information. One module named Intra-image Self-attention Seed Expansion (ISE) digs intra-image self-attentions with an expansion loss and a confidence loss to expand seed areas. The other module named Inter-image Affinity-based Noise Suppression (IAS) suppresses the noise pixels in attention maps via inter-image correlations. Extensive experiments conducted on ISIC-2017 dataset show that SLSNet achieves relatively high performance while reducing human labeling efforts. © The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd 2024.

关键词： Expansion

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