检索结果-南通市图书馆

A new method for evaluating the firing precision of multiple launch rocket system based on Bayesian theory

在线全文

学校读者我要写书评

暂无评论

Defence Technology（防务技术） 2024年第2期32卷 232-241页

作者： Yunfei Miao guoping wang Wei Tian College of Mechanical and Electrical Engineering Nanjing University of Aeronautics and AstronauticsNanjingJiangsuChina Institute of Launch Dynamics Nanjing University of Science and TechnologyNanjingJiangsuChina

How to effectively evaluate the firing precision of weapon equipment at low cost is one of the core contents of improving the test level of weapon system.A new method to evaluate the firing precision of the MLRS considering the credibility of simulation system based on Bayesian theory is proposed in this *** of all,a comprehensive index system for the credibility of the simulation system of the firing precision of the MLRS is constructed combined with the group analytic hierarchy process.A modified method for determining the comprehensive weight of the index is established to improve the rationality of the index weight *** Bayesian posterior estimation formula of firing precision considering prior information is derived in the form of mixed prior distribution,and the rationality of prior information used in estimation model is discussed *** the simulation tests,the different evaluation methods are compared to validate the effectiveness of the proposed ***,the experimental results show that the effectiveness of estimation method for firing precision is improved by more than 25%.

关键词： Multiple launch rocket system Bayesian theory Simulation credibility Mixed prior distribution Firing precision

Vegetation Development and Water Level Changes in Shenjiadian Peatland in Sanjiang Plain,Northeast China

在线全文

学校读者我要写书评

暂无评论

Chinese Geographical Science 2015年第4期25卷 451-461页

作者： wang Chunling ZHAO Hongyan wang guoping Key Laboratory of Wetland Ecology and Environment Northeast Institute of Geography and Agroecology Chinese Academy of Sciences University of Chinese Academy of Sciences Key Laboratory of Wetland Ecology and Vegetation Restoration Northeast Normal University

This paper documents a 7800-year proxy record from the Shenjiadian peatland on the Sanjiang Plain in Northeast ***-resolution plant macrofossil and colorimetric humification methods were used to reconstruct the vegetation and hydrologic history from a 193 cm-long sedimentary *** correspondence analysis(DCA) was applied to transform the raw plant macrofossil data into latent indices of peatland water *** vegetation community transited from an Equisetum fluviatile community to a Carex lasiocarpa community at approximately 3800 cal yr BP and was followed by a Carex-shrub community at approximately 480 cal yr *** on the plant macrofossil DCA axis 1 scores and humification values,we distinguished four hydrologic periods:a wet period from 7800 cal yr BP to 4500 cal yr BP,dry periods up to 1600 cal yr BP,drier periods until 300 cal yr BP,and the driest period from 300 cal yr BP until the *** a comparison with other climate records,we suggest that the East Asian summer monsoon(EAM) was the main driving force for vegetation and water level changes to the Shenjiadian peatland through its impacts on precipitation.

关键词： plant macrofossils humification Holocene peatland Northeast China

Homography-guided stereo matching for wide-baseline image interpolation

在线全文

学校读者我要写书评

暂无评论

Computational Visual Media 2022年第1期8卷 119-133页

作者： Yuan Chang Congyi Zhang Yisong Chen guoping wang Peking University Beijing 100871China Beijiing Engineering Technology Research Center of Virtual Simulation and Visualization Peking UniversityBeijing 100871China The University of Hong Kong Hong KongChina

Image interpolation has a wide range of applications such as frame rate-up conversion and free viewpoint *** significant progresses,it remains an open challenge especially for image pairs with large *** this paper,we first propose a novel optimization algorithm for motion estimation,which combines the advantages of both global optimization and a local parametric transformation *** perform optimization over dynamic label sets,which are modified after each iteration using the prior of piecewise consistency to avoid local *** we apply it to an image interpolation framework including occlusion handling and intermediate image *** validate the performance of our algorithm experimentally,and show that our approach achieves state-of-the-art performance.

关键词： image interpolation view synthesis homo-graphy propagation belief propagation

Dynamics and control of variable geometry truss manipulator

在线全文

学校读者我要写书评

暂无评论

Applied Mathematics and Mechanics(English Edition) 2017年第2期38卷 243-262页

作者： Xiaofeng LIU Qishuai wang Haiquan LI guoping CAI Department of Engineering Mechanics State Key Laboratory of Ocean Engineering Shanghai Jiao Tong University Shanghai 200240 China

Variable geometry truss manipulator （VGTM） has potential to work in the future space applications, of which a dynamic model is important to dynamic analysis and control of the system. In this paper, an approach is presented to model the dynamic equations of a VGTM by independent variables, which consists of two double-octahedral truss units and a 3-revolute-prismatic-spherical （3-RPS） parallel manipulator. In this ap- proach, the kinematic recursive relations of two adjacent bodies and geometric constrains are used to deduce the kinematic equations of the VGTM, and Jourdain＇s velocity varia- tion principle is adopted to establish the dynamic equations of the system. The validity of the proposed dynamic model is verified by comparison of numerical simulations with the software ADAMS. Besides, an active controller for trajectory tracking of the system is designed by the computed torque method. The effectiveness of the controller is numer- ically proved.

关键词： variable geometry truss manipulator (VGTM) double-octahedral truss unit,3-revolute-prismatic-spherical (3-RPS) parallel manipulator dynamic modeling activecontrol

Optical waveguide in curved and welded perovskite nanowires

在线全文

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2023年第5期66卷 1471-1479页

作者： ZHANG ZhenYu ZHANG YuPeng HONG BinBin wang guoping College of Electronics and Information Engineering Shenzhen UniversityShenzhen 518060China

Single-crystalline lead halide perovskite nanowires are emerging as promising one-dimensional blocks for nanoscience and nanotechnology,and extensive studies of nano-lasers and nano-photodetectors have been ***,as perfect confined structures,their optical waveguide performances have not been widely paid attention to up to ***,we report on the such issue on single-crystalline CsPbBr3nanowires and quantify it by near-field optical response *** waveguide is verified as total internal reflection mode at the visible band(532 nm),and its far-field end-facet coupling efficiency of 89.6%and propagation loss as low as 5.9 dB/mm are measured from the nanowire with cross-sectional geometry of~600 nm×300 *** evident bending loss exists in naturally curved nanowires,while it usually emerges in artificial-bended ones due to the wrinkled *** welded nanowire networks show significant advantages in integrated waveguides over the artificial assembled ones,due to the coupled photons at the space-confined end-facet *** surface reasoned by lattice degradation is detrimental to propagation loss,but it provides leaked channels for waveguide coupling on nanowire *** work studies the optical waveguide performance of perovskite nanowires with different geometries and goes a step further for integrated nanophotonics.

关键词： optical waveguide perovskite nanowires SNOM curved nanowire welded networks

Approximate Poisson disk sampling on mesh

在线全文

学校读者我要写书评

暂无评论

Science China(Information Sciences) 2013年第9期56卷 194-205页

作者： GENG Bo ZHANG HuiJuan wang Heng wang guoping Graphics and Interactive Technology Lab of Dept. of Computer Science Peking University The Key Lab of Machine perception and intelligent MOE

Poisson disk sampling has been widely used in many applications such as remeshing, procedural texturing, object distribution, illumination, etc. While 2D Poisson disk sampling is intensively studied in recent years, direct Poisson disk sampling on 2-manifold surface is rarely covered. In this paper, we present a novel framework which generates approximate Poisson disk distribution directly on mesh, a discrete representation of 2-manifold surfaces. Our framework is easy to implement and provides extra flexibility to specified sampling issues like feature-preserving sampling and adaptive sampling. We integrate the tensor voting method into feature detection and adaptive sample radius calculation. Remeshing as a special downstream application is also addressed. According to our experiment results, our framework is efficient, robust, and widely applicable.

关键词： Poisson disk sampling feature preserving sampling adaptive sampling remeshing tensor voting

Discrete time transfer matrix method for dynamics analysis of complex weapon systems

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2011年第5期54卷 1061-1071页

作者： RUI XiaoTing RONG Bao wang guoping HE Bin Institute of Launch Dynamics Nanjing University of Science and Technology Nanjing 210094 China

Efficient, precise dynamic modeling and analysis for complex weapon systems have become more and more important in their dynamic design and performance optimizing. As a new method developed in recent years, the discrete time transfer matrix method of multibody system is highly efficient for multibody system dynamics. In this paper, taking a shipboard gun system as an example, by deducing some new transfer equations of elements, the discrete time transfer matrix method of multibody sys- tem is used to solve the dynamics problems of complex rigid-flexible coupling weapon systems successfully. This method does not need the global dynamic equations of system and has the low order of system matrix, high computational efficiency. The proposed method has advantages for dynamic design of complex weapon systems, and can be carried over straightforwardly to other complex mechanical systems.

关键词： multibody system dynamics transfer matrix method shipboard gun finite element

Waterproof,Self‑Adhesive,and Large‑Area Luminescent Perovskite–Polymer Fiber Membranes

在线全文

学校读者我要写书评

暂无评论

Advanced Fiber Materials 2023年第5期5卷 1737-1748页

作者： Ying Chen Zhenyu Zhang Yanming Sun guoping wang Institute of Microscale Optoelectronics Shenzhen UniversityShenzhen 518060China College of Electronics and Information Engineering Shenzhen UniversityShenzhen 518060China

Recently,waterproof lighting and luminescent displays have been achieved in perovskite–polymer composite ***,practical large-area display applications are still limited to the strong electrostatic adhesion(EA)and high *** overcome these deficiencies,large-area(~600 cm2)homogeneous perovskite–polymer fiber membranes(PPFMs)are synthesized by an electrospinning strategy in this *** to the microscopic cladding of the hydrophobic polymer fibers,the electrospun PPFMs exhibit ultrastable underwater luminescence for more than 90 days,and strong EA to diverse materials without pretreatments or additional ***,by utilizing a proposed programmable laser lithography strategy,designed PPFM patterns are fabricated as the assembly blocks of large-area colorful or tridimensional ***,due to laser thermal ablation effects,the disengaged edges of these blocks are self-stitched with high mechanical stability and *** work provides a simple and effective strategy to realize waterproof,self-adhesive,and large-area display applications of perovskite nanomaterials in real world settings.

关键词： Perovskite-polymer composites Electrospinning Waterproof Large area Pattern displays Laser lithography

Dynamic modeling and H_∞ independent modal space vibration control of laminate plates

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China(Physics,Mechanics & Astronomy) 2011年第9期54卷 1638-1650页

作者： RONG Bao RUI XiaoTing wang guoping YANG FuFeng Institute of Launch Dynamics Nanjing University of Science and Technology Nanjing 210094 China

In this paper, combining the transfer matrix method and the finite element method, the modified finite element transfer matrix method is presented for high efficient dynamic modeling of laminated plates. Then, by constructing the modal filter and the disturbance force observer, and using the feedback and feedforward approaches, the H ∞ independent modal space control strategy is designed for active vibration control of laminate plates subjected to arbitrary, immeasurable disturbance forces. Compared with ordinary dynamic modeling and control methods of laminated plate structures, the proposed method has the low memory requirement, high computational efficiency and robust control performance. Formulations as well as some numerical examples are given to validate the method and the control performance.

关键词： transfer matrix method finite element laminated plate active vibration control H~ control