检索结果-内蒙古大学图书馆

Calculation of Midfrequency Transfer Function and Sensitivity of a Structural Damping System

AIAA JOURNAL 2022年第9期60卷 5600-5604页

作者： Wu, Baisheng Zhao, Xuqi Zhong, Huixiang Guangdong Univ Technol Sch Electromech Engn Guangzhou 510006 Guangdong Peoples R China Jilin Normal Univ Sch Math Siping 136000 Jilin Peoples R China

来源：评论

学校读者我要写书评

暂无评论

Heuristic Dynamic Programming iterative algorithm Design Based on BP Neural Network

Heuristic Dynamic Programming Iterative Algorithm Design Bas...

引用

International Forum on Materials Analysis and Testing Technology (IFMATT 2013)

作者： Zhao, Yu Yang, Jiye Jiangsu Food & Pharmaceut Sci Coll Dept Math Huaian 223000 Peoples R China

ISBN: (纸本)9783037859537

The time-delay delay phenomenon is a kind of widespread physical and biological phenomenon. The existence of time-delay not only give the stability of system analysis and controller design brings great difficulties but also usually make the systems unstable and even cause the system performance deteriorated. We use the adaptive dynamic iterative algorithm to solve this equation. By using the neural network to achieve the iterative algorithm, get the optimal control law of the systems with time delay. The simulation results show that the adaptive dynamic programming method to solve the optimal control of the nonlinear system is effective.

关键词： Heuristic Dynamic Programming Neural Network iterative algorithm

来源：评论

学校读者我要写书评

暂无评论

Improvement of Lattice Parameter Accuracy in Single Crystal XRD Based on a Laser-Induced X-Ray Source

引用

高压物理学报 2025年第4期39卷 9-15页

作者： LIU Jin WANG Qiannan LI Jiangtao National Key Laboratory of Shock Wave and Detonation Physics Institute of Fluid PhysicsChina Academy of Engineering PhysicsMianyang 621999SichuanChina Pico Electron Microscopy Center Innovation Institute for Ocean Materials Characterization TechnologyCenter for Advanced Studies in Precision InstrumentHainan UniversityHaikou 570228HainanChina State Key Laboratory for Environment-Friendly Energy Materials Southwest University of Science and TechnologyMianyang 621010SichuanChina

The lattice parameter,measured with sufficient accuracy,can be utilized to evaluate the quality of single crystals and to determine the equation of state for *** propose an iterative method for obtaining more precise lattice parameters using the interaction points for the pseudo-Kossel pattern obtained from laser-induced X-ray diffraction(XRD).This method has been validated by the analysis of an XRD experiment conducted on iron single ***,the method was used to calculate the compression ratio and rotated angle of an LiF sample under high pressure *** technique provides a robust tool for in-situ characterization of structural changes in single crystals under extreme *** has significant implications for studying the equation of state and phase transitions.

关键词： lattice parameter measurement accuracy single crystal X-ray diffraction iterative algorithm high pressure ratio of compression

来源：评论

学校读者我要写书评

暂无评论

An algorithm for Adaptive Assessment in Time Series Seasonal Oscillations and Its Testing Based on the Example of Variations in the CO2 Concentration in the Atmosphere

引用

IZVESTIYA ATMOSPHERIC AND OCEANIC PHYSICS 2022年第7期58卷 681-707页

作者： Deshcherevskii, A. V. Sidorin, A. Ya. Russian Acad Sci Schmidt Inst Phys Earth Moscow 123242 Russia

An adaptive model is proposed to describe time-varying seasonal effects. The seasonal average function is constructed using an iterative algorithm that provides a neat decomposition of the signal into a generalized trend, seasonal and residual components. By a trend, we mean long-term evolutionary changes in the average signal level, both unidirectional and chaotic, in the form of a slow random drift. This algorithm allows one to obtain unbiased estimates for each of the signal components, even in the presence of a significant number of missing observations. The series length is not required to be a multiple of an integer number of years. In contrast to the usual "Climate Normals" (CN) model, the considered adaptive model of seasonal effects assumes a continuous slow change in the properties of the seasonal component over time. The degree of allowable variability in seasonal effects from year to year is entered as a tunable parameter of the model. In particular, this allows one to show the dynamics of the growth of the amplitude of seasonal fluctuations in time in the form of a continuous (smooth) function without necessarily linking these changes to predetermined calendar epochs. The algorithm was tested on the atmospheric CO2 concentration monitoring series at Barrow, Mauna Loa, Tutuila, and South Pole stations located at different latitudes. The form of the seasonal variation was estimated, and the average amplitude of the seasonal variation and the rate of its change at each station were calculated. Noticeable differences in the dynamics of the studied parameters between stations are demonstrated. Mean amplitude of seasonal variation in CO2 concentration at Barrow, Mauna Loa, Tutuila, and South Pole stations in the epoch 2010-2019 was estimated as 18.15, 7.08, 1.30, and 1.26 ppm, respectively, and the average rate of increase in the amplitude of the seasonal variation in the increase in CO2 concentration in the interval 1976-2019 is 0.085, 0.0100, 0.0165, and 0.

关键词： time series time series analysis time series decomposition iterative algorithm trend periodic components seasonal periodicity algorithm testing carbon dioxide CO2 concentration in the atmosphere

来源：评论

学校读者我要写书评

暂无评论

Secure IRS-Aided Cognitive UAV Communications 23

Secure IRS-Aided Cognitive UAV Communications

引用

23rd IEEE International Conference on Communication Technology, ICCT 2023

作者： Li, An Guo, Tao Wu, Qingqing Wang, Zhiwei Yan, Liyan Hong, Sheng Nanchang University Department of Electronic Information Engineering Nanchang330031 China Shanghai Jiao Tong University Department of Electronic Engineering Shanghai200240 China

ISBN: (纸本)9798350325959

In this article, we study a novel intelligent reflecting surface (IRS)-aided cognitive unmanned aerial vehicle (Co-UAV) secure communication network, in which an IRS is exploited to improve the information transmit security. Our goal is to optimize the IRS's phase shifts, the UAV's transmit power and trajectory jointly. Aiming at the non-convex and intractable nature of this optimization objective, we present an effective iterative algorithm by combining alternating optimization (AO) technique and successive convex approximation (SCA) method so as to acquire a local suboptimal solution. Simulation results confirm the proposed algorithm is effective in significantly improving the secondary secrecy performance assisted by IRS subject to the interference temperature limit on the primary user. © 2023 IEEE.

关键词： Cognitive unmanned aerial vehicle (Co-UAV) communication intelligent reflecting surface iterative algorithm physical layer security power control

来源：评论

学校读者我要写书评

暂无评论

An analytical model of longitudinal joints in the segmental lining of shield tunnels with considering geometric nonlinearity

引用

TUNNELLING AND UNDERGROUND SPACE TECHNOLOGY 2024年 152卷

作者： Feng, Dong-Lin Wu, Huai-Na Chen, Ren-Peng Yang, Si-Qi Cheng, Hong-Zhan Hunan Univ Hunan Prov Engn Res Ctr Adv Technol & Intelligent Changsha 410082 Peoples R China Hunan Univ Key Lab Bldg Safety & Energy Efficiency Minist Educ Changsha 410082 Peoples R China Hunan Univ Coll Civil Engn Changsha 410082 Peoples R China

The previous mechanical analysis on the longitudinal joint of segmental linings commonly used the plane section assumption, in which the strains on the normal section are linearly and continuously distributed. This was proven to be overidealized according to a series of full-scale tests in existing literatures. In this paper, the nonlinear characteristics of deformation behavior for longitudinal joint were investigated with emphasis on the geometric nonlinearity of joint. A new analytical model of longitudinal joint was proposed with considering the geometric nonlinearity via employing the local plane section assumption to describe the strain distribution of joint section. The effectiveness of the proposed model was validated and parametric study (e.g. loading cycles and peak bending moment) was conducted. The results indicated the geometric nonlinearity of longitudinal joint refers to the increase area of free surface for the joint section. This nonlinearity will cause the discontinuous change of contact state which can be intuitively charactered by the height of concrete compression zone. Without considering the geometric nonlinearity, the area of concrete compression zone and bending capacity of the joint are overestimated by 45% to 100% based on the calculation result of the verification case. The increasing load cycles and peak load value deteriorate the deformation recoverability and ultimate capacity of joints. The degree of geometric nonlinearity is intensified with the increase of load cycles and peak load value but it can be alleviated if the concrete in external edge contact during overloading process.

关键词： Segmental joint Theoretical model iterative algorithm Geometric nonlinearity Complex loading condition

来源：评论

学校读者我要写书评

暂无评论

iterative algorithm of common solutions for a constrained convex minimization problem, a quasi-variational inclusion problem and the fixed point problem of a strictly pseudo-contractive mapping

引用

FIXED POINT THEORY AND APPLICATIONS 2014年第1期2014卷 54-54页

作者： Ke, Yifen Ma, Changfeng Fujian Normal Univ Sch Math & Comp Sci Fuzhou 350007 Peoples R China

In this paper, a new iterative algorithm is proposed for finding a common solution to a constrained convex minimization problem, a quasi-variational inclusion problem and the fixed point problem of a strictly pseudo-contractive mapping in a real Hilbert space. It is proved that the sequence generated by the proposed algorithm converges strongly to a common solution of the three above described problems. By applying this result to some special cases, several interesting results can be obtained.

关键词： iterative algorithm constrained convex minimization quasi-variational inclusion strictly pseudo-contractive fixed point convergence analysis

来源：评论

学校读者我要写书评

暂无评论

A new variable selection and estimation algorithm for the high-dimensional quantile single-index model

引用

COMMUNICATIONS IN STATISTICS-SIMULATION AND COMPUTATION 2024年

作者： Wang, Xuhui Ye, Wuyi Univ Sci & Technol China Sch Management Hefei 230026 Peoples R China

The single-index model (SIM) reveals the intricate relationship between the response variable and covariates, allowing for the consideration of potential heterogeneity and nonlinearity in the data, while also offering interpretability and flexibility. This paper concentrates on estimating the parameters and the unknown link function for the quantile SIM with high-dimensional covariates. We introduce a novel iterative algorithm that strikes a balance between estimation accuracy, computational efficiency, and adaptability to diverse datasets. The initial values for iteration and iteration termination conditions are also discussed. The finite sample performance is illustrated through a simulation study, demonstrating the advantages of our method in terms of accuracy and speed.

关键词： High-dimensional data iterative algorithm Quantile regression Semi-parametric Variable selection

来源：评论

学校读者我要写书评

暂无评论

A TV-minimization image-reconstruction algorithm without system matrix

引用

JOURNAL OF X-RAY SCIENCE AND TECHNOLOGY 2021年第5期29卷 851-865页

作者： Qiao, Zhiwei Lu, Yang Shanxi Univ Sch Comp & Informat Technol 92 Wucheng Rd Taiyuan 030006 Shanxi Peoples R China

PURPOSE: Total Variation (TV) minimization algorithm is a classical compressed sensing (CS) based iterative image reconstruction algorithm that can accurately reconstruct images from sparse-view projections in computed tomography (CT). However, the system matrix used in the algorithm is often too large to be stored in computer memory. The purpose of this study is to investigate a new TV algorithm based on image rotation and without system matrix to avoid the memory requirement of system matrix. METHODS: Without loss of generality, a rotation-based adaptive steepest descent-projection onto convex sets (R-ASD-POCS) algorithm is proposed and tested to solve the TV model in parallel beam CT. Specifically, simulation experiments are performed via the Shepp-Logan, FORBILD and real CT image phantoms are used to verify the inverse-crime capability of the algorithm and evaluate the sparse reconstruction capability and the noise suppression performance of the algorithm. RESULTS: Experimental results show that the algorithm can achieve inverse-crime, accurate sparse reconstruction and thus accurately reconstruct images from noisy projections. Compared with the classical ASD-POCS algorithm, the new algorithm may yield the similar image reconstruction accuracy without use of the huge system matrix, which saves the computational memory space significantly. Additionally, the results also show that R-ASD-POCS algorithm is faster than ASD-POCS. CONCLUSIONS: The proposed new algorithm can effectively solve the problem of using huge memory in large scale and iterative image reconstruction. Integrating with ASD-POCS frame, this no-system-matrix based scheme may be readily extended and applied to any iterative image reconstructions.

关键词： Rotation-based reconstruction system matrix TV minimization iterative algorithm computed tomography

来源：评论

学校读者我要写书评

暂无评论

Kinematics Analysis of 3-RRPS Parallel Mechanism 19

Kinematics Analysis of 3-RRPS Parallel Mechanism

引用

19th IEEE International Conference on Mechatronics and Automation (IEEE ICMA)

作者： Yu, Cheng Li, Bin Zhu, Jiaqi Tianjin Univ Technol Sch Mech Engn Tianjin Key Lab Adv Mechatron Syst Design & Intel Tianjin 300384 Peoples R China Tianjin Univ Technol Natl Demonstrat Ctr Expt Mech & Elect Engn Educ Tianjin Peoples R China

ISBN: (数字)9781665408530

ISBN: (纸本)9781665408530;9781665408523

In this paper, the kinematics of the 3-RRPS parallel mechanism was deeply studied, and the kinematics mathematical model of the parallel mechanism was obtained by using the method of coordinate system transformation. The inverse solution of the parallel mechanism pose was obtained by solving this equation, and the nonlinear equation was obtained from the inverse solution. The forward solution of the attitude of the parallel mechanism was calculated by solving this nonlinear equation with Jacobian matrix and Newton iterative algorithm, which is an approximate solution. Finally, we verified the correctness of the forward kinematics solution through MATLAB.

关键词： Parallel mechanism 3-RRPS Inverse pose solution iterative algorithm Forward pose solution

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：