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Joint intra-frame and inter-frame imaging algorithm for spaceborne ISAR imaging of air target 认领 引用
1
作者 ZHOU Yichen WANG Yong 《Journal of Systems Engineering and Electronics》 SCIE CSCD 2026年第2期412-430,共19页
The spaceborne inverse synthetic aperture radar(ISAR)has attracted significant attention due to its extensive observation range and imaging performance.However,the complex motion between spaceborne platform and the ai... The spaceborne inverse synthetic aperture radar(ISAR)has attracted significant attention due to its extensive observation range and imaging performance.However,the complex motion between spaceborne platform and the air target leads to complex signal modulation.The scattering anisotropy and occlusion lead to the scattering points missing problem.These problems pose a serious challenge to the traditional ISAR imaging algorithms.Aiming at the above problems,this paper proposes a joint intra-frame and inter-frame imaging algorithm based on spaceborne ISAR.In this algorithm,we divide the long coherent processing interval into several sub-apertures using the narrow-band tracking data,and each-order terms of the signal within sub-aperture is derived in detail.Then,the intra-frame algorithm based on the parametric minimized image entropy search is proposed to correct the spatial-variant phase errors caused by the complex relative motion.As to the well-focused images from different views and the rotation parameters obtained in sub-apertures,the inter-frame algorithm based on wavelet transform can perform image registration and image fusion to obtain more detailed target feature information and more complete target structure.In simulated and real-measured data experiments,the effectiveness and superiority of the proposed algorithm are validated. 展开更多
关键词 spaceborne inverse synthetic aperture radar(ISAR) long coherent processing interval division intra-frame complex motion compensation inter-frame image fusion
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Exponential time differencing based efficient SC-PML for RCS simulation 认领 引用 被引量：3
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作者 NIU Liqiang XIE Yongjun +1 位作者 JIANG Haolin WU Peiyu 《Journal of Systems Engineering and Electronics》 SCIE CSCD 2020年第4期703-711,共9页
To efficiently simulate and calculate the radar cross section(RCS) related electromagnetic problems by employing the finite-difference time-domain(FDTD) algorithm, an efficient stretched coordinate perfectly matched l... To efficiently simulate and calculate the radar cross section(RCS) related electromagnetic problems by employing the finite-difference time-domain(FDTD) algorithm, an efficient stretched coordinate perfectly matched layer(ESC-PML) based upon the exponential time differencing(ETD) method is proposed.The proposed implementation can not only reduce the number of auxiliary variables in the SC-PML regions but also maintain the ability of the original SC-PML in terms of the absorbing performance. Compared with the other existed algorithms, the ETDFDTD method shows the least memory consumption resulting in the computational efficiency. The effectiveness and efficiency of the proposed ESC-PML scheme is verified through the RCS relevant problems including the perfect E conductor(PEC) sphere model and the patch antenna model. The results indicate that the proposed scheme has the advantages of the ETD-FDTD method and ESC-PML scheme in terms of high computational efficiency and considerable computational accuracy. 展开更多
关键词 exponential time differencing(ETD) efficient stretched coordinate(ESC) finite-difference time-domain(FDTD) perfectly matched layer(PML) radar cross section(RCS)
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New Predictor-Corrector Methods Based on Exponential Time Differencing forSystems of Nonlinear Differential Equations 认领 引用 被引量：1
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作者 TANGChen YANHai-Qing ZHANGHao LIWen-Run LIUMing ZHANGGui-Min 《Communications in Theoretical Physics》 SCIE CAS 2004年第2期219-224,共6页
We present the new predictor-corrector methods for systems of nonlinear differential equations, based on the method of exponential time differencing. We compare the present schemes with the explicit multistep exponent... We present the new predictor-corrector methods for systems of nonlinear differential equations, based on the method of exponential time differencing. We compare the present schemes with the explicit multistep exponential time differencing and Adams–Bashforth–Moulton method. The numerical results show that the schemes are more accurate and more efficient than Adams predictor-corrector method. The exponential time differencing method has been developed and perfected by the present studies. 展开更多
关键词 predictor-corrector methods of exponential time differencing nonlinear system chaos
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A Homogenized Function to Recover Wave Source by Solving a Small Scale Linear System of Differencing Equations 认领 引用
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作者 Chein-Shan Liu Wen Chen Ji Lin 《Computer Modeling in Engineering & Sciences》 SCIE EI 2016年第5期421-435,共15页
In order to recover unknown space-dependent function G(x)or unknown time-dependent function H(t)in the wave source F(x;t)=G(x)H(t),we develop a technique of homogenized function and differencing equations,which can si... In order to recover unknown space-dependent function G(x)or unknown time-dependent function H(t)in the wave source F(x;t)=G(x)H(t),we develop a technique of homogenized function and differencing equations,which can significantly reduce the difficulty in the inverse wave source recovery problem,only needing to solve a few equations in the problem domain,since the initial condition/boundary conditions and a supplementary final time condition are satisfied automatically.As a consequence,the eigenfunctions are used to expand the trial solutions,and then a small scale linear system is solved to determine the expansion coefficients from the differencing equations.Because the ill-posedness of the inverse wave source problem is greatly reduced,the present method is accurate and stable against a large noise up to 50%,of which the numerical tests confirm the observation. 展开更多
关键词 Wave source recovery problem Eigenfunctions Homogenized function Differencing equations
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Image Steganography by Pixel-Value Differencing Using General Quantization Ranges 认领 引用 被引量：2
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作者 Da-Chun Wu Zong-Nan Shih 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第10期353-383,共31页
A new steganographic method by pixel-value differencing(PVD)using general quantization ranges of pixel pairs’difference values is proposed.The objective of this method is to provide a data embedding technique with a ... A new steganographic method by pixel-value differencing(PVD)using general quantization ranges of pixel pairs’difference values is proposed.The objective of this method is to provide a data embedding technique with a range table with range widths not limited to powers of 2,extending PVD-based methods to enhance their flexibility and data-embedding rates without changing their capabilities to resist security attacks.Specifically,the conventional PVD technique partitions a grayscale image into 1×2 non-overlapping blocks.The entire range[0,255]of all possible absolute values of the pixel pairs’grayscale differences in the blocks is divided into multiple quantization ranges.The width of each quantization range is a power of two to facilitate the direct embedding of the bit information with high embedding rates.Without using power-of-two range widths,the embedding rates can drop using conventional embedding techniques.In contrast,the proposed method uses general quantization range widths,and a multiple-based number conversion mechanism is employed skillfully to implement the use of nonpower-of-two range widths,with each pixel pair being employed to embed a digit in the multiple-based number.All the message bits are converted into a big multiple-based number whose digits can be embedded into the pixel pairs with a higher embedding rate.Good experimental results showed the feasibility of the proposed method and its resistance to security attacks.In addition,implementation examples are provided,where the proposed method adopts non-power-of-two range widths and employsmultiple-based number conversion to expand the data-hiding and steganalysis-resisting capabilities of other PVD methods. 展开更多
关键词 Steganography pixel-value differencing multiple-based number conversion general quantization range
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Multi-channel differencing adaptive noise cancellation with multi-kernel method 认领 引用 被引量：1
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作者 Wei Gao Jianguo Huang Jing Han 《Journal of Systems Engineering and Electronics》 SCIE CSCD 2015年第3期421-430,共10页
Although a various of existing techniques are able to improve the performance of detection of the weak interesting sig- nal, how to adaptively and efficiently attenuate the intricate noises especially in the case of n... Although a various of existing techniques are able to improve the performance of detection of the weak interesting sig- nal, how to adaptively and efficiently attenuate the intricate noises especially in the case of no available reference noise signal is still the bottleneck to be overcome. According to the characteristics of sonar arrays, a multi-channel differencing method is presented to provide the prerequisite reference noise. However, the ingre- dient of obtained reference noise is too complicated to be used to effectively reduce the interference noise only using the clas- sical linear cancellation methods. Hence, a novel adaptive noise cancellation method based on the multi-kernel normalized least- mean-square algorithm consisting of weighted linear and Gaussian kernel functions is proposed, which allows to simultaneously con- sider the cancellation of linear and nonlinear components in the reference noise. The simulation results demonstrate that the out- put signal-to-noise ratio （SNR） of the novel multi-kernel adaptive filtering method outperforms the conventional linear normalized least-mean-square method and the mono-kernel normalized least- mean-square method using the realistic noise data measured in the lake experiment. 展开更多
关键词 adaptive noise cancellation multi-channel differencing multi-kernel learning array signal processing.
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Voltage-Mode Universal Biquad Filter Employing Single Voltage Differencing Differential Input Buffered Amplifier 认领 引用 被引量：2
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作者 Kanhaiya Lal Pushkar Data Ram Bhaskar Dinesh Prasad 《Circuits and Systems》 2013年第1期44-48,共5页
A new multi function voltage-mode universal biquadratic filter using single Voltage Differencing Differential Input Buffered Amplifier (VD-DIBA), two capacitors and one resistor is proposed. The proposed configuration... A new multi function voltage-mode universal biquadratic filter using single Voltage Differencing Differential Input Buffered Amplifier (VD-DIBA), two capacitors and one resistor is proposed. The proposed configuration has four inputs and one output and can realize all the five standard filters from the same circuit configuration. The presented biquad filter offers low active and passive sensitivities. The validity of proposed universal biquadratic filter has been verified by SPICE simulation using 0.35 μm MIETEC technology. 展开更多
关键词 Voltage Differencing Differential Input Buffered Amplifier Analog Filter Voltage-Mode
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Video Inter-Frame Forgery Identification Based on Consistency of Correlation Coefficients of Gray Values 认领 引用 被引量：4
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作者 Qi Wang Zhaohong Li +1 位作者 Zhenzhen Zhang Qinglong Ma 《Journal of Computer and Communications》 2014年第4期51-57,共7页
Identifying inter-frame forgery is a hot topic in video forensics. In this paper, we propose a method based on the assumption that the correlation coefficients of gray values is consistent in an original video, while ... Identifying inter-frame forgery is a hot topic in video forensics. In this paper, we propose a method based on the assumption that the correlation coefficients of gray values is consistent in an original video, while in forgeries the consistency will be destroyed. We first extract the consistency of correlation coefficients of gray values (CCCoGV for short) after normalization and quantization as distinguishing feature to identify interframe forgeries. Then we test the CCCoGV in a large database with the help of SVM (Support Vector Machine). Experimental results show that the proposed method is efficient in classifying original videos and forgeries. Furthermore, the proposed method performs also pretty well in classifying frame insertion and frame deletion forgeries. 展开更多
关键词 Inter-Frame Forgeries Content Consistency Video Forensics
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Block-Based Steganographic Algorithm Using Modulus Function and Pixel-Value Differencing 认领 引用 被引量：3
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作者 Ahlam K. Al-Dhamari Khalid A. Darabkh 《Journal of Software Engineering and Applications》 2017年第1期56-77,共22页
The main purpose in developing the steganographic algorithms lies in achieving most of the steganographic objectives which comprise the embedding capacity, imperceptibility, security, robustness and complexity. In thi... The main purpose in developing the steganographic algorithms lies in achieving most of the steganographic objectives which comprise the embedding capacity, imperceptibility, security, robustness and complexity. In this paper, we propose a high quality steganographic algorithm using new block structure which makes a good use of both modulus function and pixel-value differencing, namely, MF-PVD. We have made many experiments with various test images from several galleries, such as USC-SIPI and UWATERLOO-LINK. The performance of our proposed algorithm is verified using three different performance metrics which include peak signal-to-noise ratio (PSNR), structural similarity index measure (SSIM), and embedding capacity (EC). Experimental results and comparisons with six pertinent state-of-art algorithms are given to prove the validation and efficiency of the proposed algorithm. 展开更多
关键词 Data Hiding Steganography Watermarking Pixel-Value Differencing Modulus Function Performance Metrics
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Multifunction Filter Employing Current Differencing Buffered Amplifier 认领 引用
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作者 Tajinder Singh Arora Udit Rana 《Circuits and Systems》 2016年第5期543-550,共8页
This paper proposes a new filter biquad circuit, which utilizes three Current Differencing Buffered Amplifiers (CDBA), two capacitors and five resistors, and operates in the trans-resistance mode. This multi-input and... This paper proposes a new filter biquad circuit, which utilizes three Current Differencing Buffered Amplifiers (CDBA), two capacitors and five resistors, and operates in the trans-resistance mode. This multi-input and single-output multifunction filter uses only grounded capacitors. All the employed resistors are either grounded or virtually grounded, which is an important parameter for its implementation as an integrated circuit. The circuit enjoys independent tunability of angular frequency and bandwidth. The 0.5 μm technology process parameters have been utilized to test and verify the performance characteristics of the circuit using PSPICE. The non-ideal analysis and sensitivity analysis, transient response, Monte-Carlo analysis and calculations of total harmonic distortion have also been shown. 展开更多
关键词 Active Filters Current Differencing Buffered Amplifier Biquadratic Filter KHN-Biquad
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New Voltage Mode Sinusoidal Oscillator Using Voltage Differencing Transconductance Amplifiers (VDTAs) 认领 引用
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作者 Nisha Walde Syed Naseem Ahmad 《Circuits and Systems》 2015年第8期173-178,共6页
The purpose of this paper is to introduce a new electronically controlled voltage mode sinusoidal oscillator (VMSO) using Voltage Differencing Transconductance Amplifiers (VDTA). The proposed circuit provides electron... The purpose of this paper is to introduce a new electronically controlled voltage mode sinusoidal oscillator (VMSO) using Voltage Differencing Transconductance Amplifiers (VDTA). The proposed circuit provides electronic control of ω0 and independent condition of oscillation (CO). It is found that the oscillator works very satisfactorily and pure sinusoidal waveforms are available at the outputs. The PSPICE simulation confirms the theoretical results. The proposed oscillator circuit employs only two VDTAs, along with two grounded capacitor and single grounded resistor. The circuit exhibits low active and passive sensitivities for ω0. Simulation results are obtained by using PSPICE software with TSMC CMOS 0.18 um process parameters. 展开更多
关键词 Voltage Differencing Transconductance Amplifier (VDTA) Voltage-Mode Circuit Oscillator
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Temporal modulation and frame-differencing enhanced high-density super-resolution optical fluctuation imaging 认领 引用
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作者 DUANTAO HOU LIWEN CHEN +6 位作者 ZHIJIA LIU KEDONG OUYANG YIAN ZHU LONGFANG YAO YIYAN FEI LAN MI JIONG MA 《Photonics Research》 SCIE EI CAS CSCD 2026年第4期1568-1587,共20页
Super-resolution microscopy has enabled nanoscale imaging beyond the diffraction limit.Among various techniques,super-resolution optical fluctuation imaging(SOFI)is notable for its hardware simplicity and suitability ... Super-resolution microscopy has enabled nanoscale imaging beyond the diffraction limit.Among various techniques,super-resolution optical fluctuation imaging(SOFI)is notable for its hardware simplicity and suitability for live-cell imaging.However,under high fluorescent labeling density,SOFI reconstructions often suffer from reduced resolution and imaging artifacts.This study proposes a super-resolution optical fluctuation imaging approach based on temporal modulation and frame-differencing(dSOFI).By employing periodic photoactivation to modulate fluorophore density and introducing a frame-differencing algorithm,dSOFI effectively reduces molecular density during the reconstruction process.The method demonstrates broad compatibility across sample types,imaging modes,and post-processing algorithms.When integrated with the commercial spinning-disk confocal system,dSOFI achieves a lateral resolution of 72 nm in live-cell imaging,and reveals a potential upper bound of lateral resolution approaching~60 nm under well-controlled acquisition conditions when combined with sparse deconvolution.dSOFI provides a broadly applicable and easy-to-implement solution for high-density super-resolution imaging,particularly under live-cell conditions. 展开更多
关键词 DSOFI high density imaging SOFI super resolution optical fluctuation imaging nanoscale imaging frame differencing temporal modulation super resolution microscopy
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Maximum bound principle preserving exponential time differencing schemes for the penalized Allen-Cahn-Ohta-Kawasaki model 认领 引用
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作者 Yingying Wang Xiao Li Zhengru Zhang 《Science China Mathematics》 SCIE CSCD 2026年第3期835-856,共22页
The nonlocal penalized Allen-Cahn-Ohta-Kawasaki(pACOK)equation,equipped with a specific nonlinear function in the Ohta-Kawasaki free energy functional,satisfies the maximum bound principle(MBP).In this paper,we develo... The nonlocal penalized Allen-Cahn-Ohta-Kawasaki(pACOK)equation,equipped with a specific nonlinear function in the Ohta-Kawasaki free energy functional,satisfies the maximum bound principle(MBP).In this paper,we develop and analyze the first-and second-order exponential time differencing(ETD)schemes for solving the p ACOK equation.The fully discrete numerical schemes are obtained by adopting the second-order central difference approximation in space.This is an initial exploration of the application of the ETD schemes on the p ACOK equation and,to the best of our knowledge,also the first work on the second-order linear scheme for this model with the complete theoretical proofs of the MBP preservation and unconditional energy stability.In addition,numerical experiments convincingly demonstrate superior accuracy and faster convergence rates of the proposed ETD schemes compared with the existing stabilized linear schemes.Furthermore,we simulate various microstructures of diblock copolymers. 展开更多
关键词 penalized Allen-Cahn-Ohta-Kawasaki equation exponential time differencing maximum bound principle energy stability diblock copolymers
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Background Subtraction and Frame Difference Based Moving Object Detection for Real-Time Surveillance 认领 引用 被引量：5
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作者 黄中文 戚飞虎 岑峰 《Journal of Donghua University(English Edition)》 EI CAS 2003年第1期15-19,共5页
A new real-time algorithm is proposed in this paperfor detecting moving object in color image sequencestaken from stationary cameras.This algorithm combines a temporal difference with an adaptive background subtractio... A new real-time algorithm is proposed in this paperfor detecting moving object in color image sequencestaken from stationary cameras.This algorithm combines a temporal difference with an adaptive background subtraction where the combination is novel.Ⅷ1en changes OCCUr.the background is automatically adapted to suit the new conditions.Forthe background model,a new model is proposed with each frame decomposed into regions and the model is based not only upon single pixel but also on the characteristic of a region.The hybrid presentationincludes a model for single pixel information and a model for the pixel’s neighboring area information.This new model of background can both improve the accuracy of segmentation due to that spatialinformation is taken into account and salientl5r speed up the processing procedure because porlion of neighboring pixel call be selected into modeling.The algorithm was successfully used in a video surveillance systern and the experiment result showsit call obtain a clearer foreground than the singleframe difference or background subtraction method. 展开更多
关键词 video surveillance background subtraction frame differencing
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北斗三频三差相位组合周跳探测与修复算法研究 认领 引用
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作者 何君洋 柳根 王坚 《测绘科学》 CSCD 北大核心 2026年第2期1-10,共10页
针对现有周跳检测方法在信号质量差、多路径效应强或电离层剧烈变化环境下灵敏度下降、易漏检或误判,以及单频或双频观测信息有限的问题,该文提出一种基于三频相位线性组合的三频三差线性相位周跳检测方法(TF3D-LP-CSD)。首先,构建两组... 针对现有周跳检测方法在信号质量差、多路径效应强或电离层剧烈变化环境下灵敏度下降、易漏检或误判,以及单频或双频观测信息有限的问题,该文提出一种基于三频相位线性组合的三频三差线性相位周跳检测方法(TF3D-LP-CSD)。首先,构建两组三频无几何与一组三频三差的线性组合,在无须预先解整周模糊度的情况下直接检测周跳突变信号,从根本上剔除整周模糊度影响;然后,在消除卫星钟差与接收机钟差的基础上,采用历元差分技术进一步抑制电离层与对流层延迟,同时利用三差处理使多路径误差和随机噪声在历元及站-卫星差分中部分抵消以获得观测序列,使周跳突变信号与背景噪声得以有效分离;最后,对整周模糊度、大气延迟、钟差和多路径效应进行多层次消除,实现了高灵敏度、低误报率和实时性的周跳检测与修复。实验结果表明,在仿真环境和实际北斗三频数据测试中,TF3D-LP-CSD方法能够准确检测并修复一般周跳、不敏感周跳及随机周跳。 展开更多
关键词 三频三差相位 历元差分技术 多路径误差 周跳检测与修复 电离层延迟
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一种解分离改进TDCP的周跳探测方法 认领 引用
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作者 刘真 高余婷 +3 位作者 马下平 薛书溶 王亚龙 孙博鹏 《导航定位学报》 CSCD 北大核心 2026年第3期120-135,共16页
针对低成本全球卫星导航系统(GNSS)接收机在复杂动态环境下易发生载波相位跳变,且传统双频探测方法易受频点缺失影响而失效的问题,提出一种基于解分离改进的时间差分载波相位(SS-ETDCP)北斗卫星导航系统(BDS)/GNSS周跳探测方法:不依赖... 针对低成本全球卫星导航系统(GNSS)接收机在复杂动态环境下易发生载波相位跳变,且传统双频探测方法易受频点缺失影响而失效的问题,提出一种基于解分离改进的时间差分载波相位(SS-ETDCP)北斗卫星导航系统(BDS)/GNSS周跳探测方法:不依赖双频观测组合,通过历元间差分削弱缓变误差,并利用解分离算法精准识别异常载波相位;然后基于开阔郊区与复杂强遮挡环境的车载动态实测数据,与传统无几何(GF)模型和墨尔本-维贝纳(MW)组合模型进行对比评估。结果表明,城市郊区环境与动态强遮挡环境SS-ETDCP法探测准确率均显著高于其他模型;城市郊区环境下BDS B2b频点周跳比从2.585%降至0.741%,定位精度达厘米级;动态强遮挡环境中BDS B2b频点周跳比从97.189%降至1.748%,定位精度达分米级,定位精度随系统数增加而提高。与传统模型相比,改进后的TDCP展示出更高的鲁棒性和可靠性,能够为推广低成本GNSS接收机的高精度定位提供参考。 展开更多
关键词 低成本接收机 解分离改进的时间差分载波相位(SS-ETDCP)法 周跳探测 高精度定位
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斜拉桥支座锚拉索力极值的多元概率全寿命预测研究与应用 认领 引用
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作者 肖翔 陈超 +3 位作者 杜连玉 陈斌 周金 王高新 《公路工程》 2026年第1期105-115,共11页
斜拉桥支座锚拉索通过对支座施加拉力,使支座保持稳定并防止结构物位移或倾覆,因此精准预测支座锚拉索在设计使用寿命内的拉力水平具有重要意义。研究了测点温度、温度梯度和支座锚拉索力的长期监测规律,分析了支座锚拉索力与均匀温度... 斜拉桥支座锚拉索通过对支座施加拉力,使支座保持稳定并防止结构物位移或倾覆,因此精准预测支座锚拉索在设计使用寿命内的拉力水平具有重要意义。研究了测点温度、温度梯度和支座锚拉索力的长期监测规律,分析了支座锚拉索力与均匀温度、温度梯度之间的相关特性,建立了支座锚拉索力的多元线性回归模型,揭示了温度梯度与支座锚拉索力的概率统计特性,提出了全寿命周期内支座锚拉索力的极值预测方法。结果表明:此桥主梁横截面存在明显的横向、竖向温度梯度,横向温差最高达到17.66℃,竖向温差最高达到16.28℃;支座锚拉索力与此桥平均温度之间的相关性散点图具有明显的线性相关特性,两者之间的线性相关程度为0.81,此外支座锚拉索力与横向温差、竖向温差也存在一定线性相关性;建立了支座锚拉索力与均匀温度、温度梯度之间的多元线性回归模型,此模型同时考虑均匀温度、横向温差和竖向温差对支座锚拉索力的影响,模型拟合值与实测值吻合较好,最大拟合误差仅为6.2%,验证了模型准确性;通过多种累积分布函数的拟合优度比较,发现温度梯度和支座锚拉索力的最佳概率统计模型均为广义极值分布函数(GEV);支座锚拉索力在全寿命周期内的极大预测值为1129.52 kN,极小预测值为706.91 kN,处于[686 kN,1 274 kN]设计安全范围内,其中全寿命周期内由温度场引起的索力变化幅度占初始设计值的26.3%,由随机特征引起的索力变化幅度占初始设计值的8.4%,可见需要重点关注桥梁运营期间温度场变化对支座锚拉索力的安全影响。此结果可为斜拉桥支座锚拉索力在设计使用寿命内的安全状况评估提供重要参考。 展开更多
关键词 斜拉桥 支座锚拉索力 极值预测 温致索力多元线性回归模型 温差累积分布函数
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融合梯度模拟权重和自适应差分的灰狼优化算法 认领 引用
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作者 徐世杰 高岳林 《宁夏师范大学学报》 2026年第1期55-68,共14页
针对灰狼优化算法不足,提出融合梯度模拟权重和自适应差分的灰狼优化算法.首先,设计多收敛因子以增加全局勘探能力,且维持局部开发能力;其次,利用分组方式将概率自适应差分策略与梯度模拟的动态权重策略进行结合,前者具有增加种群多样... 针对灰狼优化算法不足,提出融合梯度模拟权重和自适应差分的灰狼优化算法.首先,设计多收敛因子以增加全局勘探能力,且维持局部开发能力;其次,利用分组方式将概率自适应差分策略与梯度模拟的动态权重策略进行结合,前者具有增加种群多样性和全局优化的能力,后者有效提高收敛速度和精度;最后,设计反向学习的高斯-柯西变异以增加算法的跳出局部最优能力.通过与5个先进的智能优化算法、3个灰狼变体算法比较以及消融实验方法,验证该算法的有效性和先进性.16个经典测试函数和优化Richards模型参数问题上的实验结果表明,该算法在收敛速度和收敛精度上具有显著优势,且在参数优化方面也有效. 展开更多
关键词 灰狼优化算法 双收敛因子 自适应差分 梯度模拟 Richards模型
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Autonomous orbit determination using epoch-differenced gravity gradients and starlight refraction 认领 引用 被引量：5
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作者 Pei CHEN Tengda SUN Xiucong SUN 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2017年第5期1740-1749,共10页
Autonomous orbit determination via integration of epoch-differenced gravity gradients and starlight refraction is proposed in this paper for low-Earth-orbiting satellites operating in GPSdenied environments. Starlight... Autonomous orbit determination via integration of epoch-differenced gravity gradients and starlight refraction is proposed in this paper for low-Earth-orbiting satellites operating in GPSdenied environments. Starlight refraction compensates for the significant along-track position error that occurs from only using gravity gradients and benefits from integration in terms of improved accuracy in radial and cross-track position estimates. The between-epoch differencing of gravity gradients is employed to eliminate slowly varying measurement biases and noise near the orbit revolution frequency. The refraction angle measurements are directly used and its Jacobian matrix derived from an implicit observation equation. An information fusion filter based on a sequential extended Kalman filter is developed for the orbit determination. Truth-model simulations are used to test the performance of the algorithm, and the effects of differencing intervals and orbital heights are analyzed. A semi-simulation study using actual gravity gradient data from the Gravity field and steady-state Ocean Circulation Explorer（GOCE） combined with simulated starlight refraction measurements is further conducted, and a three-dimensional position accuracy of better than 100 m is achieved. 展开更多
关键词 Autonomous orbit determination Epoch-differenced gravity gradients GOCE Information fusion filter Navigation Starlight refraction
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Note on Filon-type integration for higher order exponential time differencing methods in stiff systems 认领 引用
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作者 XIANG Shu-huang 《Journal of Central South University of Technology》 2005年第Z1期298-303,共6页
The Filon-type quadrature is efficient for highly oscillatory functions - Fourier transforms. Based on Cox and Matthews' ETD schemes, the higher order single step exponential time differencing schemes are presente... The Filon-type quadrature is efficient for highly oscillatory functions - Fourier transforms. Based on Cox and Matthews' ETD schemes, the higher order single step exponential time differencing schemes are presented based on the Filon-type integration and the A-stability of the two-order Adams-Bashforth exponential time differencing scheme is considered. The effectiveness and accuracy of the schemes is tested. 展开更多
关键词 exponential time differencing method stiff system Filon method Runge-Kutta method
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