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Dual smoothing ionospheric gradient monitoring algorithm for dual-frequency BDS GBAS 被引量:2
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作者 Zhipeng WANG Yu YIN +3 位作者 Dan SONG Kun FANG Qiang LI Xiao LI 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2020年第12期3395-3404,共10页
In this study,a Dual Smoothing Ionospheric Gradient Monitor Algorithm(DSIGMA)was developed for Code-Carrier Divergence(CCD)faults of dual-frequency Ground-Based Augmentation Systems(GBAS)based on the Bei Dou Navigatio... In this study,a Dual Smoothing Ionospheric Gradient Monitor Algorithm(DSIGMA)was developed for Code-Carrier Divergence(CCD)faults of dual-frequency Ground-Based Augmentation Systems(GBAS)based on the Bei Dou Navigation Satellite System(BDS).Divergence-Free(DF)combinations of the signals were used to form test statistics for a dualfrequency DSIGMA.First,the single-frequency DSIGMA was reviewed,which supports the GBAS approach service type D(GAST-D)for protection against the effect of large ionospheric gradients.The single-frequency DSIGMA was used to create a novel input scheme for the dual-frequency DSIGMA by introducing DF combinations.The steady states of the test statistics were also analysed.The monitors were characterized using BDS measurement data,whereby standard deviations of 0.0432 and 0.0639 m for the proposed two test statistics were used to calculate the monitor threshold.An extensive simulation was designed to assess the monitor performance by comparing the Probability of Missed Detection(PMD)according to the differential error with the range domain PMD limits under different fault modes.The results showed that the proposed algorithm has a higher integrity performance than the single-frequency monitor.The minimum detectable divergence with the same missed probability is less than 50%that of GAST-D. 展开更多
关键词 Approach Augmentation Integrity Ionosphere-monitoring Satellite navigation smoothing algorithms Steady state Threshold
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Smoothing Newton Algorithm for Linear Programming over Symmetric Cones 被引量:2
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作者 刘晓红 倪铁 《Transactions of Tianjin University》 EI CAS 2009年第3期216-221,共6页
By using the theory of Euclidean Jordan algebras,based on a new class of smoothing functions,the QiSun-Zhou's smoothing Newton algorithm is extended to solve linear programming over symmetric cones(SCLP).The algor... By using the theory of Euclidean Jordan algebras,based on a new class of smoothing functions,the QiSun-Zhou's smoothing Newton algorithm is extended to solve linear programming over symmetric cones(SCLP).The algorithm is globally convergent under suitable assumptions. 展开更多
关键词 linear programming symmetric cone Euclidean Jordan algebra smoothing algorithm
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NON-INTERIOR SMOOTHING ALGORITHM FOR FRICTIONAL CONTACT PROBLEMS 被引量:1
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作者 张洪武 何素艳 李兴斯 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2004年第1期47-58,共12页
A new algorithm for solving the three-dimensional elastic contact problem with friction is presented. The algorithm is a non-interior smoothing algorithm based on an NCP-function. The parametric variational principle ... A new algorithm for solving the three-dimensional elastic contact problem with friction is presented. The algorithm is a non-interior smoothing algorithm based on an NCP-function. The parametric variational principle and parametric quadratic programming method were applied to the analysis of three-dimensional frictional contact problem. The solution of the contact problem was finally reduced to a linear complementarity problem, which was reformulated as a system of nonsmooth equations via an NCP-function. A smoothing approximation to the nonsmooth equations was given by the aggregate function. A Newton method was used to solve the resulting smoothing nonlinear equations. The algorithm presented is easy to understand and implement. The reliability and efficiency of this algorithm are demonstrated both by the numerical experiments of LCP in mathematical way and the examples of contact problems in mechanics. 展开更多
关键词 three-dimensional frictional contact problem parametic quadratic programming method linear complementarity problem NCP-function aggregate function non-interior smoothing algorithm
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Visible and Near-Infrared Spectroscopy with Multi-Parameters Optimization of Savitzky-Golay Smoothing Applied to Rapid Analysis of Soil Cr Content of Pearl River Delta 被引量:3
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作者 Xiaowen Shi Lijun Yao Tao Pan 《Journal of Geoscience and Environment Protection》 2021年第3期75-83,共9页
Using visible and near-infrared (Vis-NIR) spectroscopy combined with partial least squares (PLS) regression, the rapid reagent-free analysis model for chromium (Cr) content in tideland reclamation soil in the Pearl Ri... Using visible and near-infrared (Vis-NIR) spectroscopy combined with partial least squares (PLS) regression, the rapid reagent-free analysis model for chromium (Cr) content in tideland reclamation soil in the Pearl River Delta, China was established. Based on Savitzky-Golay (SG) smoothing and PLS regression, a multi-parameters optimization platform (SG-PLS) covering 264 modes was constructed to select the appropriately spectral preprocessing mode. The optimal SG-PLS model was determined according to the prediction effect. The selected optimal parameters <em>d, p, m</em> and LV were 2, 6, 23 and 8, respectively. Using the validation samples that were not involved in modeling, the root mean square error (SEP<sub>V</sub>), relative root mean square error (R-SEP<sub>V</sub>) and correlation coefficients (R<sub>P, V</sub>) of prediction were 11.66 mg<span style="white-space:nowrap;">&middot;</span>kg<sup>-1</sup>, 10.7% and 0.722, respectively. The results indicated that the feasibility of using Vis-NIR spectroscopy combined with SG-PLS method to analyze soil Cr content. The constructed multi-parameters optimization platform with SG-PLS is expected to be applied to a wider field of analysis. The rapid detection method has important application values to large-scale agricultural production. 展开更多
关键词 Soil Heavy Metal CHROMIUM Visible and Near-Infrared Spectroscopy Rapid Reagent-Free Analysis savitzky-golay smoothing
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An energy spectrum smoothing algorithm based on TCC-DEE 被引量:3
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作者 Bo Lu Yong Chen +3 位作者 YueZhu Yan-Ji Yang Wei.WeiCui Yu-MeiZhou 《Nuclear Science and Techniques》 SCIE CAS CSCD 2017年第10期1-8,共8页
A smoothing algorithm for energy spectrum based on differential nonlinearity(DNL) error elimination with total counts conservation for high-energy particle detector systems is presented. It is physics based and is onl... A smoothing algorithm for energy spectrum based on differential nonlinearity(DNL) error elimination with total counts conservation for high-energy particle detector systems is presented. It is physics based and is only determined by the DNL error of analog-to-digital converter device itself. From the experimental results, this algorithm slightly improves both noise performance and energy resolution, while greatly reduces the testing errors by almost a half compared to their original values. In addition, the reduced-x^2 statistic for evaluating the Gaussian fitting goodness is significantly reduced by almost two orders after smoothing. As a typical verification example,this algorithm is successfully applied in the ground calibration of the Low Energy X-ray Instrument onboard the Hard X-ray Modulation Telescope(HXMT-LE) satellite,lending it a powerful, nondestructive and low-cost tool for both calibration and data processing for high-energy particle detector systems. 展开更多
关键词 平滑算法 硬X射线调制望远镜 探测器系统 基础 能谱 高能粒子 测试误差 微分非线性
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A Control Strategy for Smoothing Active Power Fluctuation of Wind Farm with Flywheel Energy Storage System Based on Improved Wind Power Prediction Algorithm
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作者 J. C. Wang X. R. Wang 《Energy and Power Engineering》 2013年第4期387-392,共6页
The fluctuation of active power output of wind farm has many negative impacts on large-scale wind power integration into power grid. In this paper, flywheel energy storage system (FESS) was connected to AC side of the... The fluctuation of active power output of wind farm has many negative impacts on large-scale wind power integration into power grid. In this paper, flywheel energy storage system (FESS) was connected to AC side of the doubly-fed induction generator (DFIG) wind farm to realize smooth control of wind power output. Based on improved wind power prediction algorithm and wind speed-power curve modeling, a new smooth control strategy with the FESS was proposed. The requirement of power system dispatch for wind power prediction and flywheel rotor speed limit were taken into consideration during the process. While smoothing the wind power fluctuation, FESS can track short-term planned output of wind farm. It was demonstrated by quantitative analysis of simulation results that the proposed control strategy can smooth the active power fluctuation of wind farm effectively and thereby improve power quality of the power grid. 展开更多
关键词 WIND POWER Generation FESS WIND POWER Prediction IMPROVED Time-series algorithm Active POWER smooth Control
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Medical Quality-of-Service Optimization in Wireless Telemedicine System Using Optimal Smoothing Algorithm
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作者 Sodhro Ali Hassan Ye Li 《E-Health Telecommunication Systems and Networks》 2013年第1期1-8,共8页
In this paper we consider the transmission of stored video from a server to a client for medical applications such as, Telemonitoring, to optimize medical quality of service (m-QoS) and to examine how the client buffe... In this paper we consider the transmission of stored video from a server to a client for medical applications such as, Telemonitoring, to optimize medical quality of service (m-QoS) and to examine how the client buffer space can be used efficiently and effectively towards reducing the rate variability of the compressed variable bit rate (VBR) video. Three basic results are presented. First, we show how to obtain the greatest possible reduction in rate variability when sending stored video to client with a given buffer size. Second, how to reduce high peak data rate of compressed VBR video when a patient is moving/walking very fast in hospital. Third, we evaluate the impact of optimal smoothing algorithm on the network parameters such as, peak-to-mean ratio, standard deviation, delay, jitter, average delay and average jitter to optimize the m-QoS. To resolve these all problems we used optimal smoothing algorithm and show its performance over a set of long MPEG-4 encoded video traces. Simulation results show that m-QoS is optimized by minimizing network metrics. 展开更多
关键词 WIRELESS TELEMEDICINE System MEDICAL QoS OPTIMAL smoothing algorithm Mobile Health
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Smoothing Newton Algorithm for Solving Generalized Complementarity Problem
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作者 刘晓红 倪铁 《Transactions of Tianjin University》 EI CAS 2010年第1期75-79,共5页
The generalized complementarity problem includes the well-known nonlinear complementarity problem and linear complementarity problem as special cases.In this paper, based on a class of smoothing functions, a smoothing... The generalized complementarity problem includes the well-known nonlinear complementarity problem and linear complementarity problem as special cases.In this paper, based on a class of smoothing functions, a smoothing Newton-type algorithm is proposed for solving the generalized complementarity problem.Under suitable assumptions, the proposed algorithm is well-defined and global convergent. 展开更多
关键词 generalized complementarity problem smoothing Newton algorithm NCP function global convergence
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Smoothing Newton Algorithm for Nonlinear Complementarity Problem with a PFunction
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作者 刘丹红 黄涛 王萍 《Transactions of Tianjin University》 EI CAS 2007年第5期379-386,共8页
By using a smoothing function,the P nonlinear complementarity problem(P NCP)can be reformulated as a parameterized smooth equation.A Newton method is proposed to solve this equation.The iteration sequence generated by... By using a smoothing function,the P nonlinear complementarity problem(P NCP)can be reformulated as a parameterized smooth equation.A Newton method is proposed to solve this equation.The iteration sequence generated by the proposed algorithm is bounded and this algorithm is proved to be globally convergent under an assumption that the P NCP has a nonempty solution set.This assumption is weaker than the ones used in most existing smoothing algorithms.In particular,the solution obtained by the proposed algorithm is shown to be a maximally complementary solution of the P NCP without any additional assumption. 展开更多
关键词 P.nonlinear complementarity problem smoothing Newton algorithm maximally complementary solution
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低剂量胸部CT联合smooth算法重组对冠状动脉钙化的评估价值
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作者 王淑颖 陈馨 《中国CT和MRI杂志》 2025年第5期74-77,共4页
目的探讨低剂量胸部CT联合smooth算法重组对冠状动脉钙化评估的临床价值。方法选取2020年10月至2022年11月本院收治的70例冠状动脉钙化患者的一般资料进行回顾性分析。患者均开展心电门控CT平扫(ECG-gated CT)和非门控胸部低剂量CT扫描(... 目的探讨低剂量胸部CT联合smooth算法重组对冠状动脉钙化评估的临床价值。方法选取2020年10月至2022年11月本院收治的70例冠状动脉钙化患者的一般资料进行回顾性分析。患者均开展心电门控CT平扫(ECG-gated CT)和非门控胸部低剂量CT扫描(Low-dose computed tomography,LDCT),并将其设为A组和B组,其中B组每个患者图像都分别采用smooth、standard、sharp三种算法重组,再依次设为B1组、B2组、B3组。比较两位放射科医师对四组图像质量主观评价(背景噪声、整体图像质量评分)的一致性以及A、B1、B2、B3组图像质量的主观和客观指标情况和A、B组CT辐射剂量情况。结果两位放射科医师对A组、B1组、B2组、B3组背景噪声评分结果ICC分别为0.779、0.775、0.752、0.772,对整体图像质量评分结果ICC分别为0.854、0.856、0.873、0.810;B1组背景噪声、整体图像质量评分与A组相比较差异不显著(P>0.05),但B2组和B3组与A组背景噪声、整体图像质量评分比较均有明显差异(P<0.05);与A组相比较,B1、B2、B3组噪声值均较高(P<0.05),且B1组噪声值均小于B2、B3组(P<0.05);与A组相比较,B1、B2、B3组CNR、SNR值较低(P<0.05),且B1组CNR、SNR值均大于B2、B3组(P<0.05);与A组相比较,B组CTDlvol、DLP、ED剂量均较低(P<0.05)。结论将低剂量胸部CT扫描配合smooth算法重组应用于冠状动脉钙化的评估中,可获得较高的主观和客观图像质量,具有较高的临床应用价值,值得推广和使用。 展开更多
关键词 冠状动脉钙化 低剂量胸部CT smooth算法 应用价值
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The extraction and smoothing algorithms for γ-ray spectrum of a CdZnTe detector system
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作者 许鹏 王宋 +2 位作者 蔡星会 李如松 霍勇刚 《Nuclear Science and Techniques》 SCIE CAS CSCD 2014年第5期53-56,共4页
The extraction algorithms for pulse amplitude and smoothing of energy spectrum have a great influence on energy spectrum of γ-rays during the digital detection and analysis procedure. For a CdZnTe digital γ detector... The extraction algorithms for pulse amplitude and smoothing of energy spectrum have a great influence on energy spectrum of γ-rays during the digital detection and analysis procedure. For a CdZnTe digital γ detector system, different extraction algorithms for pulse amplitude and smoothing of energy spectrum are discussed in this paper. The results show that extraction of pulse amplitude using the first-order derivative method and smoothing of energy spectrum using the wavelet transformation method may obtain energy spectrum with good performance. 展开更多
关键词 探测器系统 提取算法 平滑算法 碲锌镉 γ射线谱 γ射线能谱 小波变换方法 脉冲幅度
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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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Variable structure multiple model fixed-interval smoothing 被引量:1
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作者 Bolun ZHANG Yongxin GAO Zhansheng DUAN 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2023年第2期139-148,共10页
This paper focuses on fixed-interval smoothing for stochastic hybrid systems.When the truth-mode mismatch is encountered,existing smoothing methods based on fixed structure of model-set have significant performance de... This paper focuses on fixed-interval smoothing for stochastic hybrid systems.When the truth-mode mismatch is encountered,existing smoothing methods based on fixed structure of model-set have significant performance degradation and are inapplicable.We develop a fixedinterval smoothing method based on forward-and backward-filtering in the Variable Structure Multiple Model(VSMM)framework in this paper.We propose to use the Simplified Equivalent model Interacting Multiple Model(SEIMM)in the forward and the backward filters to handle the difficulty of different mode-sets used in both filters,and design a re-filtering procedure in the model-switching stage to enhance the estimation performance.To improve the computational efficiency,we make the basic model-set adaptive by the Likely-Model Set(LMS)algorithm.It turns out that the smoothing performance is further improved by the LMS due to less competition among models.Simulation results are provided to demonstrate the better performance and the computational efficiency of our proposed smoothing algorithms. 展开更多
关键词 Fixed-interval smoothing Model-set adaptation Multiple model estimation smoothing algorithm Variable structure
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Fast Sparse Multipath Channel Estimation with Smooth L0 Algorithm for Broadband Wireless Communication Systems 被引量:1
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作者 Guan Gui Qun Wan +1 位作者 Ni Na Wang Cong Yu Huang 《Communications and Network》 2011年第1期1-7,共7页
Broadband wireless channels are often time dispersive and become strongly frequency selective in delay spread domain. Commonly, these channels are composed of a few dominant coefficients and a large part of coefficien... Broadband wireless channels are often time dispersive and become strongly frequency selective in delay spread domain. Commonly, these channels are composed of a few dominant coefficients and a large part of coefficients are approximately zero or under noise floor. To exploit sparsity of multi-path channels (MPCs), there are various methods have been proposed. They are, namely, greedy algorithms, iterative algorithms, and convex program. The former two algorithms are easy to be implemented but not stable;on the other hand, the last method is stable but difficult to be implemented as practical channel estimation problems be-cause of computational complexity. In this paper, we introduce a novel channel estimation strategy using smooth L0 (SL0) algorithm which combines stable and low complexity. Computer simulations confirm the effectiveness of the introduced algorithm. We also give various simulations to verify the sensing training signal method. 展开更多
关键词 smooth L0 algorithm RESTRICTED ISOMETRY Property SPARSE Channel Estimation Compressed Sensing
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A NON-MONOTONE SMOOTHING NEWTON ALGORITHM FOR SOLVING THE SYSTEM OF GENERALIZED ABSOLUTE VALUE EQUATIONS
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作者 Cairong Chen Dongmei Yu +1 位作者 Deren Han Changfeng Ma 《Journal of Computational Mathematics》 2025年第2期438-460,共23页
The system of generalized absolute value equations(GAVE)has attracted more and more attention in the optimization community.In this paper,by introducing a smoothing function,we develop a smoothing Newton algorithm wit... The system of generalized absolute value equations(GAVE)has attracted more and more attention in the optimization community.In this paper,by introducing a smoothing function,we develop a smoothing Newton algorithm with non-monotone line search to solve the GAVE.We show that the non-monotone algorithm is globally and locally quadratically convergent under a weaker assumption than those given in most existing algorithms for solving the GAVE.Numerical results are given to demonstrate the viability and efficiency of the approach. 展开更多
关键词 Generalized absolute value equations smoothing function smoothing Newton algorithm Non-monotone line search Global and local quadratic convergence
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PERFORMANCE ANALYSIS FOR ATM SWITCHING OF MIXED CONTINUOUS-BIT-RATE AND BURSTY TRAFFIC WITH SMOOTHING FUNCTION
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作者 Liao Jianxin Li Lemin Sun Hairong(Beijing University of Posts and Telecommunications, Beijing 100088) (University of Electronic Science and Tecnnclogy of China, Chengdu 610054) 《Journal of Electronics(China)》 1997年第2期133-139,共7页
Traditional packet switching networks have typically employed window-based congestion control schemes in order to regulate traffic flow. In ATM networks, the high speed of the communication links and the varied nature... Traditional packet switching networks have typically employed window-based congestion control schemes in order to regulate traffic flow. In ATM networks, the high speed of the communication links and the varied nature of the carried traffic make such schemes inappropriate. Therefore, simpler and more efficient schemes have to be proposed to improve the congestion control for ATM switching. This paper presents an exact performance analysis of ATM switching whose inputs consist of Continuous-Bit-Rate(CBR) and bursty traffic. The CBR traffic and bursty traffic are described by Bernoulli process and the Interrupted Bernoulli Process(IBP), respectively. Bursty traffic smoothing mechanism is analyzed. With the use of a recursive algorithm, the cell loss probability and the average delay for ATM switching of mixed CBR and bursty traffic are exactly calculated. Traffic smoothing could be implemented at a slower peak rate keeping the average rate constant or decreasing the average bursty length. Both numerical 展开更多
关键词 ATM Interrupted BERNOULLI process BURSTINESS TRAFFIC smoothing RECURSIVE algorithm
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Greedy Algorithm in m-Term Approximation for Periodic Besov Class with Mixed Smoothness
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作者 宋占杰 叶培新 《Transactions of Tianjin University》 EI CAS 2009年第1期75-78,共4页
Nonlinear m-term approximation plays an important role in machine learning, signal processing and statistical estimating. In this paper by means of a nondecreasing dominated function, a greedy adaptive compression num... Nonlinear m-term approximation plays an important role in machine learning, signal processing and statistical estimating. In this paper by means of a nondecreasing dominated function, a greedy adaptive compression numerical algorithm in the best m -term approximation with regard to tensor product wavelet-type basis is pro-posed. The algorithm provides the asymptotically optimal approximation for the class of periodic functions with mixed Besov smoothness in the L q norm. Moreover, it depends only on the expansion of function f by tensor pro-duct wavelet-type basis, but neither on q nor on any special features of f. 展开更多
关键词 greedy algorithm m -term approximation Besov space mixed smoothness
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极高地应力条件下光面爆破围岩损伤规律研究 被引量:2
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作者 黄永辉 占宇飞 +2 位作者 张洪波 李清林 阮迅 《振动与冲击》 北大核心 2025年第6期104-112,共9页
针对深埋隧道开挖过程中存在极高地应力的情况,为研究地应力对光面爆破围岩损伤产生的影响,采用基于ANSYS/LS-DYNA软件的数值模拟方法,通过结构化网格-有限元-粒子流耦合算法(structured mesh-finite element-particle flow coupling al... 针对深埋隧道开挖过程中存在极高地应力的情况,为研究地应力对光面爆破围岩损伤产生的影响,采用基于ANSYS/LS-DYNA软件的数值模拟方法,通过结构化网格-有限元-粒子流耦合算法(structured mesh-finite element-particle flow coupling algorithm,S-FEM-SPH)进行三维模拟。研究在双向等值地应力0~40 MPa条件下的光面爆破围岩损伤规律,研究结果表明:边帮和顶板处的围岩损伤度根据爆心距的变化分为水平直线阶段和反“S”型曲线下降阶段;在反“S”型曲线下降阶段,距离爆心距中间位置的围岩,损伤度随爆心距的下降速率大;地应力对边帮和顶板处的围岩损伤均有影响,但对边帮处围岩损伤的影响大于顶板处,当地应力大于20 MPa时影响更加明显;通过对比边帮和顶板处有效塑性应变和围岩损伤深度随地应力的变化规律,从而验证了围岩损伤深度随地应力增加呈现先减小后增大变化规律的正确性。 展开更多
关键词 数值模拟 光面爆破 极高地应力 围岩损伤 S-FEM-SPH算法
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飞机轮胎-湿滑道面相互作用SPH算法仿真分析 被引量:2
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作者 蔡靖 黄钰岱 +2 位作者 李琪 李岳 戴轩 《北京航空航天大学学报》 北大核心 2025年第1期53-62,共10页
针对飞机在湿滑道面上的滑水问题,采用光滑粒子流体动力学(SPH)算法建立了飞机轮胎-湿滑道面有限元模型,与流固耦合算法(CEL)模型进行对比,显示了SPH算法的优越性,进而分析了不同轮胎速度及水膜厚度对轮胎与湿滑道面相互作用的影响规律... 针对飞机在湿滑道面上的滑水问题,采用光滑粒子流体动力学(SPH)算法建立了飞机轮胎-湿滑道面有限元模型,与流固耦合算法(CEL)模型进行对比,显示了SPH算法的优越性,进而分析了不同轮胎速度及水膜厚度对轮胎与湿滑道面相互作用的影响规律。结果表明,SPH模型得到的临界滑水速度与CEL模型结果相差不超过5%;舰首波、侧向羽流等流体特征更为明显立体;平均运算效率较CEL模型提高36.5%。利用SPH模型分析可得,道面支撑力随轮胎速度增加呈先平缓下降再急速下降的趋势,水膜厚度为3~13 mm时,急速下降段所在轮胎速度区间为170~260 km/h,基本处于A320飞机的着陆滑跑速度范围内,应增强对飞机滑水事故风险的防范;位移阻力随着轮胎速度增加呈先增大后减小的趋势,且在轮胎达到临界滑水速度时取得最大值,进而提出利用位移阻力最大值确定临界滑水速度的方法;侧向羽流最大溅水高度随轮胎速度增加呈先升高后降低的趋势,在接近临界滑水速度时达到最大值;舰首波最大溅水高度低于侧向羽流最大溅水高度,且随轮胎速度增加而降低,达到临界滑水速度时舰首波接近消失,2种溅水特征的最大溅水高度值均低于A320飞机发动机的最小离地高度0.680 m,不会对发动机产生影响。 展开更多
关键词 交通运输工程 轮胎-道面相互作用 光滑粒子流体动力学算法 临界滑水速度 道面支撑力 位移阻力 溅水高度
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基于AFD融合算法的运输机器人路径规划方法 被引量:1
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作者 袁杰 张迎港 +3 位作者 加尔肯别克 张宁宁 刘超 谢霖伟 《农业机械学报》 北大核心 2025年第6期594-607,共14页
为提高运输机器人在导航中的自主性和安全性,需要进行有效合理的路径规划。本研究提出了一种改进型AFD(A*Fuzzy-DWA)融合算法,以解决经典A*算法在运输机器人路径规划中存在的问题,如搜索时间长、路径冗余、拐点多且不平滑、动态避障能... 为提高运输机器人在导航中的自主性和安全性,需要进行有效合理的路径规划。本研究提出了一种改进型AFD(A*Fuzzy-DWA)融合算法,以解决经典A*算法在运输机器人路径规划中存在的问题,如搜索时间长、路径冗余、拐点多且不平滑、动态避障能力不足等。该算法通过设计障碍率评价指标优化评价函数以减少搜索时间和遍历节点,进而设计Smooth Floyd方法简化全局路径,并采用圆内切平滑策略进一步优化路径,最后设计评价函数权重模糊推理方法提高局部路径规划效率,从而实现全面的路径优化。仿真实验结果表明,与对比算法相比,AFD算法在静态和动态环境下的全局及局部路径长度和运行时间均显著减小。实际场景验证进一步证实了该算法在提升运输机器人自主导航能力和安全性方面的有效性。 展开更多
关键词 运输机器人 路径规划 smooth Floyd方法 圆内切策略 模糊推理 融合算法
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