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NONLINEAR FILTER METHOD OF GPS DYNAMIC POSITIONING BASED ON BANCROFT ALGORITHM 被引量:3
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作者 ZHANG Qin TAO Ben-zao +1 位作者 ZHAO Chao-ying WANG Li 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 2005年第2期170-176,共7页
Because of the ignored items after linearization,the extended Kalman filter(EKF)becomes a form of suboptimal gradient descent algorithm.The emanative tendency exists in GPS solution when the filter equations are ill-p... Because of the ignored items after linearization,the extended Kalman filter(EKF)becomes a form of suboptimal gradient descent algorithm.The emanative tendency exists in GPS solution when the filter equations are ill-posed.The deviation in the estimation cannot be avoided.Furthermore,the true solution may be lost in pseudorange positioning because the linearized pseudorange equations are partial solutions.To solve the above problems in GPS dynamic positioning by using EKF,a closed-form Kalman filter method called the two-stage algorithm is presented for the nonlinear algebraic solution of GPS dynamic positioning based on the global nonlinear least squares closed algorithm--Bancroft numerical algorithm of American.The method separates the spatial parts from temporal parts during processing the GPS filter problems,and solves the nonlinear GPS dynamic positioning,thus getting stable and reliable dynamic positioning solutions. 展开更多
关键词 GPs dynamic positioning bancroft algorithm extended Kalman filter algorithm
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基于图像信息算法的2024年新疆乌什M_(S)7.1地震回溯性预测研究
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作者 袁伏全 黄浩 +2 位作者 徐玮阳 张晓清 刘兴盛 《地震研究》 北大核心 2026年第2期198-206,共9页
使用1970年以来新疆天山地震带及邻区的地震目录资料,基于图像信息(PI)算法,计算得到2016—2028年该地区逐年滑动的预测窗PI热点分布图像,并使用工作特征图表法(ROC)和R值评分法对PI算法的预测效能进行了检验。结果表明:①在2020—2024... 使用1970年以来新疆天山地震带及邻区的地震目录资料,基于图像信息(PI)算法,计算得到2016—2028年该地区逐年滑动的预测窗PI热点分布图像,并使用工作特征图表法(ROC)和R值评分法对PI算法的预测效能进行了检验。结果表明:①在2020—2024年回溯性预测图像中,2024年新疆乌什M_(S)7.1地震震中区域存在PI热点,具有较强的发震地点指示意义。②在5个回溯性预测时间窗(2016—2020年、2017—2021年、2018—2022年、2019—2023年、2020—2024年)内的PI热点图像演化过程中,乌什M_(S)7.1地震震中附近PI热点表现为“出现—逐步密集增强”,发震概率增大,该热点附近发震紧迫性和地震危险性增强。③ROC检验和R值评分显示,PI算法优于随机预测方法。④综合热点信息演化图像分析得到,南天山地震带的西南端强震危险性较高。 展开更多
关键词 乌什M_(s)7.1地震 PI算法 回溯性预测 地震热点 ROC检验
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Fast Mixture Distribution Optimization for Rain-Flow Matrix of a Steel Arch Bridge by REBMIX Algorithm
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作者 Yuliang He Weihong Lou +1 位作者 Da Hang Youhua Su 《Structural Durability & Health Monitoring》 2025年第4期887-902,共16页
The computational accuracy and efficiency of modeling the stress spectrum derived from bridge monitoring data significantly influence the fatigue life assessment of steel bridges.Therefore,determining the optimal stre... The computational accuracy and efficiency of modeling the stress spectrum derived from bridge monitoring data significantly influence the fatigue life assessment of steel bridges.Therefore,determining the optimal stress spectrum model is crucial for further fatigue reliability analysis.This study investigates the performance of the REBMIX algorithm in modeling both univariate(stress range)and multivariate(stress range and mean stress)distributions of the rain-flowmatrix for a steel arch bridge,usingAkaike’s Information Criterion(AIC)as a performance metric.Four types of finitemixture distributions—Normal,Lognormal,Weibull,and Gamma—are employed tomodel the stress range.Additionally,mixed distributions,including Normal-Normal,Lognormal-Normal,Weibull-Normal,and Gamma-Normal,are utilized to model the joint distribution of stress range and mean stress.The REBMIX algorithm estimates the number of components,component weights,and component parameters for each candidate finite mixture distribution.The results demonstrate that the REBMIX algorithm-based mixture parameter estimation approach effectively identifies the optimal distribution based on AIC values.Furthermore,the algorithm exhibits superior computational efficiency compared to traditional methods,making it highly suitable for practical applications. 展开更多
关键词 steel bridge stress spectrum finite mixture distribution REBMIX algorithm Akaike’s information criterion
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一种基于Bancroft算法的GPS动态抗差自适应滤波 被引量:12
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作者 张双成 杨元喜 +1 位作者 张勤 高为广 《武汉大学学报(信息科学版)》 EI CSCD 北大核心 2007年第4期309-311,共3页
基于抗差自适应滤波的思想,结合非线性Bancroft算法的特点,提出了一种基于Bancroft算法的GPS动态抗差自适应滤波。计算表明,该算法不仅在一定程度上减弱了由于线性化忽略高次项对导航解的影响,而且再次证实抗差自适应滤波在控制扰动异... 基于抗差自适应滤波的思想,结合非线性Bancroft算法的特点,提出了一种基于Bancroft算法的GPS动态抗差自适应滤波。计算表明,该算法不仅在一定程度上减弱了由于线性化忽略高次项对导航解的影响,而且再次证实抗差自适应滤波在控制扰动异常的有效性和合理性。 展开更多
关键词 GPs动态导航 bancroft算法 非线性最小二乘 自适应滤波
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基于Bancroft算法的多点定位TOA-LS估计 被引量:5
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作者 林云松 孙卓振 彭良福 《电子学报》 EI CAS CSCD 北大核心 2012年第3期621-624,共4页
由于目标信号的发射时间未知,无源定位技术大多利用TDOA(到达时间差)进行目标定位.本文将求解GPS单点定位的Bancroft算法应用于TOA(到达时间)多点定位方程的求解,提出了基于Bancroft算法的无源多点定位TOA-LS(最小二乘)估计算法.TOA-LS... 由于目标信号的发射时间未知,无源定位技术大多利用TDOA(到达时间差)进行目标定位.本文将求解GPS单点定位的Bancroft算法应用于TOA(到达时间)多点定位方程的求解,提出了基于Bancroft算法的无源多点定位TOA-LS(最小二乘)估计算法.TOA-LS包含三个线性方程,其加权系数与目标位置和目标信号发射时间相关.采用Ban-croft算法给出初始值并求解TOA-LS方程,完成加权系数的迭代更新.仿真结果表明对不同几何位置的目标,TOA-LS估计可获得接近理论方差下界的近似最优的性能. 展开更多
关键词 bancroft算法 多点定位 TOA估计 最小二乘法
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基于正规基的大规模S盒FPGA设计与实现
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作者 张磊 李国元 +2 位作者 洪睿鹏 王建新 肖超恩 《密码学报(中英文)》 北大核心 2025年第4期854-869,共16页
传统上的分组密码S盒硬件实现采用查表法,其实现效果受到芯片资源的限制.针对16-bit大规模S盒在FPGA硬件实现中资源消耗大的问题,本文提出了基于复合域中正规基的S盒构造方法,研究使用较少的硬件资源实现16-bit S盒.首先,设计了基于复... 传统上的分组密码S盒硬件实现采用查表法,其实现效果受到芯片资源的限制.针对16-bit大规模S盒在FPGA硬件实现中资源消耗大的问题,本文提出了基于复合域中正规基的S盒构造方法,研究使用较少的硬件资源实现16-bit S盒.首先,设计了基于复合域的16-bit S盒构造实现方案,构建了线性的同构映射矩阵及其逆矩阵.其次,通过映射矩阵使有限域GF(2^(16))的乘法逆转换到复合域GF((((2^(2))^(2))^(2))^(2))上,进而将非线性的高维乘法逆简化为低维子域运算.然后,通过分析各级复合域不同参数对S盒实现的影响,筛选最优参数.最后,结合所提出的16-bit S盒构造实现框架,本文利用Xilinx公司的Vivado开发工具,以MK-3算法的16-bit S盒为例进行了FPGA仿真验证与性能分析.结果表明,本文构造方法实现的MK-3算法S盒需要186个LUT,时钟频率为114.129 MHz,在时钟频率/LUT的性能指标下达到了0.61360.同目前已公开文献同类方法中的最优实现性能0.43538相比,性能提升了40.93%.本文的16-bit S盒实现方案能够在降低硬件资源消耗的同时保持密码算法较高的运行频率,对有基于有限域构造的S盒的高效软硬件实现具有一定的参考价值. 展开更多
关键词 大规模s 复合域 正规基 MK-3算法 FPGA
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Bancroft算法应用于GPS/BDS/GLONASS三系统伪距单点定位 被引量:2
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作者 侯鹏宇 宋子远 +2 位作者 石波 柯成 王胜利 《海洋测绘》 CSCD 2018年第6期33-36,共4页
为了提高多系统组合单点定位的运算效率,将Bancroft算法推广应用于GPS/BDS/GLONASS三系统伪距单点定位,并推导了该方法的详细计算流程,比较了Bancroft算法、最小二乘算法和组合两种算法的精度、迭代次数以及运算时间。利用实测数据进行... 为了提高多系统组合单点定位的运算效率,将Bancroft算法推广应用于GPS/BDS/GLONASS三系统伪距单点定位,并推导了该方法的详细计算流程,比较了Bancroft算法、最小二乘算法和组合两种算法的精度、迭代次数以及运算时间。利用实测数据进行实验,结果表明,3种算法精度相当,Bancroft算法比最小二乘算法迭代次数少,运算效率提高了38%,利用Bancroft为最小二乘算法提供初值,收敛速度加快,运算效率提高了36%。最终得出结论,Bancroft算法应用于GPS/BDS/GLONASS三系统伪距单点定位满足精度要求,且Bancroft算法对于减少迭代次数,提高运算效率有重要意义。 展开更多
关键词 全球导航卫星系统 bancroft算法 GPs/BDs/GLONAss 组合单点定位 解算效率
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Smooth constraint inversion technique in genetic algorithms and its application to surface wave study in the Tibetan Plateau 被引量:3
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作者 吴建平 明跃红 曾融生 《Acta Seismologica Sinica(English Edition)》 EI CSCD 2001年第1期49-57,共9页
Smooth constraint is important in linear inversion, but it is difficult to apply directly to model parameters in genetic algorithms. If the model parameters are smoothed in iteration, the diversity of models will be g... Smooth constraint is important in linear inversion, but it is difficult to apply directly to model parameters in genetic algorithms. If the model parameters are smoothed in iteration, the diversity of models will be greatly suppressed and all the models in population will tend to equal in a few iterations, so the optimal solution meeting requirement can not be obtained. In this paper, an indirect smooth constraint technique is introduced to genetic inversion. In this method, the new models produced in iteration are smoothed, then used as theoretical models in calculation of misfit function, but in process of iteration only the original models are used in order to keep the diversity of models. The technique is effective in inversion of surface wave and receiver function. Using this technique, we invert the phase velocity of Raleigh wave in the Tibetan Plateau, revealing the horizontal variation of S wave velocity structure near the center of the Tibetan Plateau. The results show that the S wave velocity in the north is relatively lower than that in the south. For most paths there is a lower velocity zone with 12-25 km thick at the depth of 15-40 km. The lower velocity zone in upper mantle is located below the depth of 100 km, and the thickness is usually 40-80 km, but for a few paths reach to 100 km thick. Among the area of Ando, Maqi and Ushu stations, there is an obvious lower velocity zone with the lowest velocity of 4.2-4.3 km/s at the depth of 90-230 km. Based on the S wave velocity structures of different paths and former data, we infer that the subduction of the Indian Plate is delimited nearby the Yarlung Zangbo suture zone. 展开更多
关键词 genetic algorithm smooth constraint surface wave s wave velocity structure Tibetan Plateau
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A hybrid quantum encoding algorithm of vector quantization for image compression 被引量:4
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作者 庞朝阳 周正威 郭光灿 《Chinese Physics B》 SCIE EI CAS CSCD 2006年第12期3039-3043,共5页
Many classical encoding algorithms of vector quantization (VQ) of image compression that can obtain global optimal solution have computational complexity O(N). A pure quantum VQ encoding algorithm with probability... Many classical encoding algorithms of vector quantization (VQ) of image compression that can obtain global optimal solution have computational complexity O(N). A pure quantum VQ encoding algorithm with probability of success near 100% has been proposed, that performs operations 45√N times approximately. In this paper, a hybrid quantum VQ encoding algorithm between the classical method and the quantum algorithm is presented. The number of its operations is less than √N for most images, and it is more efficient than the pure quantum algorithm. 展开更多
关键词 vector quantization Grover's algorithm image compression quantum algorithm
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Hydraulic Optimization of a Double-channel Pump's Impeller Based on Multi-objective Genetic Algorithm 被引量:12
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作者 ZHAO Binjuan WANG Yu +2 位作者 CHEN Huilong QIU Jing HOU Duohua 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2015年第3期634-640,共7页
Computational fluid dynamics(CFD) can give a lot of potentially very useful information for hydraulic optimization design of pumps, however, it cannot directly state what kind of modification should be made to impro... Computational fluid dynamics(CFD) can give a lot of potentially very useful information for hydraulic optimization design of pumps, however, it cannot directly state what kind of modification should be made to improve such hydrodynamic performance. In this paper, a more convenient and effective approach is proposed by combined using of CFD, multi-objective genetic algorithm(MOGA) and artificial neural networks(ANN) for a double-channel pump's impeller, with maximum head and efficiency set as optimization objectives, four key geometrical parameters including inlet diameter, outlet diameter, exit width and midline wrap angle chosen as optimization parameters. Firstly, a multi-fidelity fitness assignment system in which fitness of impellers serving as training and comparison samples for ANN is evaluated by CFD, meanwhile fitness of impellers generated by MOGA is evaluated by ANN, is established and dramatically reduces the computational expense. Then, a modified MOGA optimization process, in which selection is performed independently in two sub-populations according to two optimization objectives, crossover and mutation is performed afterword in the merged population, is developed to ensure the global optimal solution to be found. Finally, Pareto optimal frontier is found after 500 steps of iterations, and two optimal design schemes are chosen according to the design requirements. The preliminary and optimal design schemes are compared, and the comparing results show that hydraulic performances of both pumps 1 and 2 are improved, with the head and efficiency of pump 1 increased by 5.7% and 5.2%, respectively in the design working conditions, meanwhile shaft power decreased in all working conditions, the head and efficiency of pump 2 increased by 11.7% and 5.9%, respectively while shaft power increased by 5.5%. Inner flow field analyses also show that the backflow phenomenon significantly diminishes at the entrance of the optimal impellers 1 and 2, both the area of vortex and intensity of vortex decreases in the whole flow channel. This paper provides a promising tool to solve the hydraulic optimization problem of pumps' impellers. 展开更多
关键词 double-channel pump's impeller multi-objective genetic algorithm artificial neural network computational fluid dynamics(CFD) UNI
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GPS定位中扩展卡尔曼滤波和基于Bancroft算法的2步滤波法的比较分析
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作者 马晓君 赵长胜 +1 位作者 夏美娟 赵雯雯 《江苏师范大学学报(自然科学版)》 CAS 2015年第1期84-85,共2页
GPS定位中常用的线性卡尔曼滤波模型的精度不能完全满足要求.为此,介绍了非线性卡尔曼滤波常用的扩展卡尔曼滤波(EKF)和基于Bancroft算法的2步滤波法.算例分析表明,基于Bancroft算法的2步滤波法较优.
关键词 GPs定位 非线性卡尔曼滤波 扩展卡尔曼滤波 bancroft算法
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Automatic Algorithm Programming Model Based on the Improved Morgan's Refinement Calculus 被引量:5
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作者 ZUO Zhengkang HU Ying +2 位作者 HUANG Qing WANG Yuan WANG Changjing 《Wuhan University Journal of Natural Sciences》 CAS CSCD 2022年第5期405-414,共10页
The automatic algorithm programming model can increase the dependability and efficiency of algorithm program development,including specification generation,program refinement,and formal verification.However,the existi... The automatic algorithm programming model can increase the dependability and efficiency of algorithm program development,including specification generation,program refinement,and formal verification.However,the existing model has two flaws:incompleteness of program refinement and inadequate automation of formal verification.This paper proposes an automatic algorithm programming model based on the improved Morgan’s refinement calculus.It extends the Morgan’s refinement calculus rules and designs the C++generation system for realizing the complete process of refinement.Meanwhile,the automation tools VCG(Verification Condition Generator)and Isabelle are used to improve the automation of formal verification.An example of a stock’s maximum income demonstrates the effectiveness of the proposed model.Furthermore,the proposed model has some relevance for automatic software generation. 展开更多
关键词 automatic algorithm programming model program refinement VCG IsABELLE Morgan’s refinement calculus
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DETERMINING THE STRUCTURES AND PARAMETERS OF RADIAL BASIS FUNCTION NEURAL NETWORKS USING IMPROVED GENETIC ALGORITHMS 被引量:1
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作者 Meiqin Liu Jida Chen 《Journal of Central South University》 SCIE EI CAS 1998年第2期68-73,共6页
The method of determining the structures and parameters of radial basis function neural networks(RBFNNs) using improved genetic algorithms is proposed. Akaike′s information criterion (AIC) with generalization error t... The method of determining the structures and parameters of radial basis function neural networks(RBFNNs) using improved genetic algorithms is proposed. Akaike′s information criterion (AIC) with generalization error term is used as the best criterion of optimizing the structures and parameters of networks. It is shown from the simulation results that the method not only improves the approximation and generalization capability of RBFNNs ,but also obtain the optimal or suboptimal structures of networks. 展开更多
关键词 RADIAL BAsIs function neural network GENETIC algorithms Akaike′s information CRITERION OVERFITTING
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Image Segmentation of Brain MR Images Using Otsu’s Based Hybrid WCMFO Algorithm 被引量:6
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作者 A.Renugambal K.Selva Bhuvaneswari 《Computers, Materials & Continua》 SCIE EI 2020年第8期681-700,共20页
In this study,a novel hybrid Water Cycle Moth-Flame Optimization(WCMFO)algorithm is proposed for multilevel thresholding brain image segmentation in Magnetic Resonance(MR)image slices.WCMFO constitutes a hybrid betwee... In this study,a novel hybrid Water Cycle Moth-Flame Optimization(WCMFO)algorithm is proposed for multilevel thresholding brain image segmentation in Magnetic Resonance(MR)image slices.WCMFO constitutes a hybrid between the two techniques,comprising the water cycle and moth-flame optimization algorithms.The optimal thresholds are obtained by maximizing the between class variance(Otsu’s function)of the image.To test the performance of threshold searching process,the proposed algorithm has been evaluated on standard benchmark of ten axial T2-weighted brain MR images for image segmentation.The experimental outcomes infer that it produces better optimal threshold values at a greater and quicker convergence rate.In contrast to other state-of-the-art methods,namely Adaptive Wind Driven Optimization(AWDO),Adaptive Bacterial Foraging(ABF)and Particle Swarm Optimization(PSO),the proposed algorithm has been found to be better at producing the best objective function,Peak Signal-to-Noise Ratio(PSNR),Standard Deviation(STD)and lower computational time values.Further,it was observed thatthe segmented image gives greater detail when the threshold level increases.Moreover,the statistical test result confirms that the best and mean values are almost zero and the average difference between best and mean value 1.86 is obtained through the 30 executions of the proposed algorithm.Thus,these images will lead to better segments of gray,white and cerebrospinal fluid that enable better clinical choices and diagnoses using a proposed algorithm. 展开更多
关键词 Hybrid WCMFO algorithm Otsu’s function multilevel thresholding image segmentation brain MR image
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A quantum search algorithm of two entangled registers to realize quantum discrete Fourier transform of signal processing 被引量:2
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作者 庞朝阳 胡本琼 《Chinese Physics B》 SCIE EI CAS CSCD 2008年第9期3220-3226,共7页
The discrete Fourier transform (DFT) is the base of modern signal processing. 1-dimensional fast Fourier transform (1D FFT) and 2D FFT have time complexity O(N log N) and O(N^2 log N) respectively. Since 1965,... The discrete Fourier transform (DFT) is the base of modern signal processing. 1-dimensional fast Fourier transform (1D FFT) and 2D FFT have time complexity O(N log N) and O(N^2 log N) respectively. Since 1965, there has been no more essential breakthrough for the design of fast DFT algorithm. DFT has two properties. One property is that DFT is energy conservation transform. The other property is that many DFT coefficients are close to zero. The basic idea of this paper is that the generalized Grover's iteration can perform the computation of DFT which acts on the entangled states to search the big DFT coefficients until these big coefficients contain nearly all energy. One-dimensional quantum DFT (1D QDFT) and two-dimensional quantum DFT (2D QDFT) are presented in this paper. The quantum algorithm for convolution estimation is also presented in this paper. Compared with FFT, 1D and 2D QDFT have time complexity O(v/N) and O(N) respectively. QDFT and quantum convolution demonstrate that quantum computation to process classical signal is possible. 展开更多
关键词 Grover's algorithm entangled state DFT QDFT
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Comparative analysis of various modularization algorithms and species specific study of VEGF signaling pathways 被引量:2
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作者 Namrata Tomar Losiana Nayak Rajat K. De 《Journal of Biomedical Science and Engineering》 2010年第10期931-942,共12页
In biology, signal transduction refers to a process by which a cell converts one kind of signal or stimulus into another. It involves ordered sequences of biochemical reactions inside the cell. These cascades of react... In biology, signal transduction refers to a process by which a cell converts one kind of signal or stimulus into another. It involves ordered sequences of biochemical reactions inside the cell. These cascades of reactions are carried out by enzymes and activated by second messengers. Signal transduction pathways are complex in nature. Each pathway is responsible for tuning one or more biological functions in the intracellular environment as well as more than one pathway interact among themselves to carry forward a single biological function. Such kind of behavior of these pathways makes understanding difficult. Hence, for the sake of simplicity, they need to be partitioned into smaller modules and then analyzed. We took VEGF signaling pathway, which is responsible for angiogenesis for this kind of modularized study. Modules were obtained by applying the algorithm of Nayak and De (Nayak and De, 2007) for different complexity values. These sets of modules were compared among themselves to get the best set of modules for an optimal complexity value. The best set of modules compared with four different partitioning algorithms namely, Farhat’s (Farhat, 1998), Greedy (Chartrand and Oellermann, 1993), Kernighan-Lin’s (Kernighan and Lin, 1970) and Newman’s community finding algorithm (Newman, 2006). These comparisons enabled us to decide which of the aforementioned algorithms was the best one to create partitions from human VEGF signaling pathway. The optimal complexity value, on which the best set of modules was obtained, was used to get modules from different species for comparative study. Comparison among these modules would shed light on the trend of development of VEGF signaling pathway over these species. 展开更多
关键词 signal TRANsDUCTION PATHWAY VEGF PATHWAY Complexity Value KEGG Database MODULARIZATION Newman’s Community Finding algorithm Kernighan-Lin’s algorithm Farhat’s algorithm and GREEDY algorithm.
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Routing Protocol Based on Grover’s Searching Algorithm for Mobile Ad-hoc Networks 被引量:3
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作者 孟利民 宋文波 《China Communications》 SCIE CSCD 2013年第3期145-156,共12页
In Mobile Ad-hoc Networks (MANETs), routing protocols directly affect various indices of network Quality of Service (QoS), so they play an important role in network performance. To address the drawbacks associated wit... In Mobile Ad-hoc Networks (MANETs), routing protocols directly affect various indices of network Quality of Service (QoS), so they play an important role in network performance. To address the drawbacks associated with traditional routing protocols in MANETs, such as poor anti-fading performance and slow convergence rate, for basic Dynamic Source Routing (DSR), we propose a new routing model based on Grover's searching algorithm. With this new routing model, each node maintains a node vector function, and all the nodes can obtain a node probability vector using Grover's algorithm, and then select an optimal routing according to node probability. Simulation results show that compared with DSR, this new routing protocol can effectively extend the network lifetime, as well as reduce the network delay and the number of routing hops. It can also significantly improve the anti-jamming capability of the network. 展开更多
关键词 Grover's channel fading additive bit error rate searching algorithm noise network delay
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Design of quantum VQ iteration and quantum VQ encoding algorithm taking O(√N) steps for data compression 被引量:2
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作者 庞朝阳 周正威 +1 位作者 陈平形 郭光灿 《Chinese Physics B》 SCIE EI CAS CSCD 2006年第3期618-623,共6页
Vector quantization (VQ) is an important data compression method. The key of the encoding of VQ is to find the closest vector among N vectors for a feature vector. Many classical linear search algorithms take O(N)... Vector quantization (VQ) is an important data compression method. The key of the encoding of VQ is to find the closest vector among N vectors for a feature vector. Many classical linear search algorithms take O(N) steps of distance computing between two vectors. The quantum VQ iteration and corresponding quantum VQ encoding algorithm that takes O(√N) steps are presented in this paper. The unitary operation of distance computing can be performed on a number of vectors simultaneously because the quantum state exists in a superposition of states. The quantum VQ iteration comprises three oracles, by contrast many quantum algorithms have only one oracle, such as Shor's factorization algorithm and Grover's algorithm. Entanglement state is generated and used, by contrast the state in Grover's algorithm is not an entanglement state. The quantum VQ iteration is a rotation over subspace, by contrast the Grover iteration is a rotation over global space. The quantum VQ iteration extends the Grover iteration to the more complex search that requires more oracles. The method of the quantum VQ iteration is universal. 展开更多
关键词 data compression vector quantization Grover's algorithm quantum VQ iteration
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SINGLE PROJECTION ALGORITHM FOR VARIATIONAL INEQUALITIES IN BANACH SPACES WITH APPLICATION TO CONTACT PROBLEM 被引量:3
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作者 Yekini SHEHU 《Acta Mathematica Scientia》 SCIE CSCD 2020年第4期1045-1063,共19页
We study the single projection algorithm of Tseng for solving a variational inequality problem in a 2-uniformly convex Banach space.The underline cost function of the variational inequality is assumed to be monotone a... We study the single projection algorithm of Tseng for solving a variational inequality problem in a 2-uniformly convex Banach space.The underline cost function of the variational inequality is assumed to be monotone and Lipschitz continuous.A weak convergence result is obtained under reasonable assumptions on the variable step-sizes.We also give the strong convergence result for when the underline cost function is strongly monotone and Lipchitz continuous.For this strong convergence case,the proposed method does not require prior knowledge of the modulus of strong monotonicity and the Lipschitz constant of the cost function as input parameters,rather,the variable step-sizes are diminishing and non-summable.The asymptotic estimate of the convergence rate for the strong convergence case is also given.For completeness,we give another strong convergence result using the idea of Halpern iteration when the cost function is monotone and Lipschitz continuous and the variable step-sizes are bounded by the inverse of the Lipschitz constant of the cost function.Finally,we give an example of a contact problem where our proposed method can be applied. 展开更多
关键词 variational inequality 2-uniformly convex Banach space Tseng’s algorithm strong convergence rate of convergence
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基于XGBoost与改进D-S证据理论的油浸式变压器故障诊断方法
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作者 陈辉 白雪婷 +3 位作者 吴一庆 江友华 徐非非 叶尚兴 《仪表技术》 2025年第4期72-77,81,共7页
针对油浸式变压器故障诊断中存在的油中溶解气体数据量不足及传统D-S证据理论故障诊断精度低的问题,提出了一种基于XGBoost与改进D-S证据理论的变压器故障诊断方法。通过单一气体特征衍生构建包含溶解气体含量及其比值的双结构特征集,... 针对油浸式变压器故障诊断中存在的油中溶解气体数据量不足及传统D-S证据理论故障诊断精度低的问题,提出了一种基于XGBoost与改进D-S证据理论的变压器故障诊断方法。通过单一气体特征衍生构建包含溶解气体含量及其比值的双结构特征集,并利用XGBoost算法筛选出最优故障特征子集;基于K-近邻算法计算特征模型值与待识别样本间贴近度,生成基本概率分配(BPA)函数;通过信念散度距离实现证据再分配,并采用D-S证据理论合成规则进行多源证据融合,以提高诊断准确性。实验结果表明,所提方法的故障诊断准确率达到90.21%,相较于IEC三比值法、灰色关联分析、CART、WOA-BP、GA-SVM分别提高了11.91%、10.91%、9.81%、8.71%和3.21%,显著提升了变压器故障诊断的可靠性。 展开更多
关键词 油浸式变压器 故障诊断 XGBoost算法 D-s证据理论 K-近邻算法
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