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An optimized algorithm and the verification methods for improving the volumetric error modeling accuracy of precision machine tools

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INTERNATIONAL JOURNAL OF ADVANCED MANUFACTURING TECHNOLOGY 2021年第11-12期112卷 3001-3015页

作者： Liu, Hui Ling, Si-ying Wang, Li-ding Yu, Zhen-jiang Wang, Xiao-dong Dalian Univ Technol Res Ctr Micro Syst Technol Dalian 116024 Peoples R China Dalian Univ Technol Natl Educ Minist Precis & Nontradit Machining Technol Key Lab Dalian 116024 Peoples R China

Referring to the error modeling technology used in precision machine tools, it is difficult for machine tool builders to understand the effects of the theoretical modeling accuracy on the precision machining in the designing stages, where error components are represented by parameters. Therefore, this study is proposed to overcome certain theoretical calculation errors for a parametric form of volumetric error modeling and to examine verification method for judging the modeling precision. Based on the mathematical theory, a novel optimized algorithm is presented, as well as its verification methods. With the two new methods, it is effective to identify theoretical calculation errors and verify the accuracy of error modeling. Meanwhile, the proposed algorithm, with a form grinding machine tool being as an illustration example, is tested and validated by means of numerical simulations in the Matlab. The results reveal that the modeling accuracy of the error characteristic matrix is improved and enhanced by the algorithm, and the two verification methods can check the veracity of parametric modeling precision in different ways. Especially, the second method can check and isolate quantitatively the theoretical calculation errors. At the same time, it is a theoretical guidance for choosing a suitable treatment to meet the accuracy of an error model represented by parametric variables during iterations of the characteristic matrices. These two prediction veracity and uncertainty of the modeling precision can be evaluated. Furthermore, the algorithm and checking methods can be extended to ultra-precision multi-axis machine tools.

关键词： Precision machine tools Modeling precision optimized algorithm Verification method Numerical simulation

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Effect of temperature on inversion concentration of NO2 differential absorption lidar and optimized algorithm

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JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER 2022年 277卷 107975-107975页

作者： Liu, Qiuwu Chen, Yafeng Yang, Jie Jian, Huang Hu, Shunxing Hanshan Normal Univ Coll Phys & Elect Engn Chaozhou 521041 Peoples R China 38th Res Inst China Elect Technol Corp Hefei 230030 Peoples R China Anhui Univ Sci & Technol Huainan 232001 Peoples R China Chinese Acad Sci Anhui Inst Opt & Fine Mech Key Lab Atmospher Composit & Opt Radiat Hefei 230031 Peoples R China

A differential absorption lidar (DIAL) for measurement of atmospheric nitrogen dioxide (NO2) concentration is developed based on atmospheric backscattered signals. Two Nd:YAG lasers are used to pump into two dye lasers to produce two wavelengths lambda on (448.1 nm) and lambda off (446.6 nm), respectively. The NO2 absorption cross section varies with the change of ambient temperature. The changes of NO2 absorption cross section and the influence of inversion concentration are analyzed. The results show that when the horizontal profile is measured with the absorption cross section at room temperature of 20 degrees C as the reference value, the relative error of 1% can be caused by the temperature change of 1 degrees C. In vertical profile measurement, on the ground below 3 km, every 100 m increase in altitude can bring a relative error of 0.6%. By correcting the absorption cross section affected by temperature, the relative error of the measured concentration is less than 5%.On this basis, the experimental observation of atmospheric NO2 concentration profiles was carried out, and errors induced by temperature change were corrected. The experimental results show that the system is stable and reliable, and the temperature correction algorithm is effective. (C) 2021 The Authors. Published by Elsevier Ltd.

关键词： Nitrogen dioxide Absorption cross section Temperature change Differential absorption lidar optimized algorithm

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An optimized algorithm for calculating the average path length of complex network 10

An optimized algorithm for calculating the average path leng...

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10th International Symposium on Computational Intelligence and Design (ISCID)

作者： Chen, Bin Cao, Lei PLA Univ Sci & Tech Inst Command Informat Syst Nanjing Jiangsu Peoples R China

ISBN: (纸本)9781538636756

to calculate the average path length of a large-scale complex network accurately and efficiently is always an important topic in the study of complex networks. For this purpose, an optimized algorithm is proposed based on reachability matrix as well as its efficiency analysis. The basic idea of this algorithm is to construct network distance matrix through network reachability matrix firstly, then to calculate the average path length according to distance matrix. It is proved and verified that the proposed algorithm is much more efficient than traditional algorithms like Floyd and Warshall algorithms for calculating large-scale complex networks with small-world effect.

关键词： large-scale complex network the average path length optimized algorithm reachability matrix

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Validation of an optimized algorithm to Use Kinect in a Non-Structured Environment for Sit-to-Stand Analysis 37

Validation of an Optimized Algorithm to Use Kinect in a Non-...

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37th Annual International Conference of the IEEE-Engineering-in-Medicine-and-Biology-Society (EMBC)

作者： Cippitelli, Enea Gasparrini, Samuele Spinsante, Susanna Gambi, Ennio Verdini, Federica Burattini, Laura Di Nardo, Francesco Fioretti, Sandro Univ Politecn Marche Dipartimento Ingn Informaz I-60131 Ancona Italy

ISBN: (纸本)9781424492701

The aim of this work is to obtain reliable kinematic measures relative to the execution of the Sit-to-Stand functional evaluation test, by low-cost and widely diffused instrumentation, that even non-experienced users can adopt in non-structured environments, like ambulatory or domestic settings. In particular, the paper refers to a low cost RGB-Depth sensor widely used in the gaming scenario like the Microsoft Kinect sensor. An algorithm is proposed that allows a reliable measure of human motion in a sagittal view. The performance of the proposed algorithm is compared to other two classic commercial algorithms. Results obtained by all the three algorithms have been compared to kinematic results obtained by the use of a stereophotogrammetric system that represents the gold-standard for kinematic measurement of human movement. Average errors of about 4 degrees, both for the trunk/leg angle and for the knee flexion/extension angle, have been obtained by the proposed algorithm and open the way to its possible adoption in non-clinical environments and further applications.

关键词： RGB optimized algorithm kinematic measurement

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Investigation on plastic and brittle characteristic of magnesium aluminum spinel in ultra-precision grinding

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PRECISION ENGINEERING-JOURNAL OF THE INTERNATIONAL SOCIETIES FOR PRECISION ENGINEERING AND NANOTECHNOLOGY 2025年 94卷 358-375页

作者： Gu, Peng Zhou, Yunxiang Sun, Chenchen Luo, Zhongjin Jiang, Zhenhua Shi, Zhuoqi Donghua Univ Coll Mech Engn Shanghai 201620 Peoples R China Donghua Univ Inst Artificial Intelligence Shanghai 201620 Peoples R China Shanghai Jiao Tong Univ Sch Mech Engn Shanghai 200240 Peoples R China Leading Opt Shanghai Co Ltd Shanghai 201100 Peoples R China

Magnesium aluminate spinel is utilized in aerospace, optics, and electronics due to its optical properties, strength, thermal stability, and corrosion resistance. Ultra-precision grinding delivers superior surface finishing, optimal for hard and brittle substances. Surface quality after ultra-precision grinding affects optical performance significantly. In this paper, the material removal mechanism of magnesium aluminate spinel is investigated. A comprehensive method for evaluating the three-dimensional surface after ultra-precision grinding is proposed, which clearly describes the distribution of surface states. Surface error indicators are suggested for the plasticity and brittleness domain of ground surfaces. Additionally, three-dimensional surface analysis of magnesium aluminate spinel after ultra-precision grinding is performed utilizing Fourier transform. The optimized ultraprecision grinding process parameters by the firefly algorithm are obtained as ns = 20200 ***-1, vw = 1.2 mm min-1, ap = 1.5 mu m. The mid-frequency surface roughness is 0.015 mu m, and the profile height is 0.23 mu m. This research achieves an optimal balance between grinding efficiency and surface quality, offering guidelines for the grinding processes for other brittle and hard materials.

关键词： Magnesium aluminate spinel Ultra-precision grinding Three-dimensional surface reconstruction surface error Fourier transform optimized algorithm

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Analytical model and design method of corrugated steel-concrete composite girders under torsion

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STRUCTURES 2024年 70卷

作者： Zhang, Hao Zhao, Qiu Chen, Yiyan Fang, Xiaojun Yang, Zhaohui Yang, Xiaoqiang Fuzhou Univ Coll Civil Engn Fuzhou 350108 Peoples R China Hong Kong Polytech Univ Dept Civil & Environm Engn Hung Hom Kowloon Hong Kong Peoples R China Guangzhou Univ Earthquake Engn Res & Test Ctr Prov Key Lab Earthquake Engn & Appl Tech Guangzhou Peoples R China Washington State Univ Sch Mech & Mat Engn Pullman WA USA

The torsional effect of prestressed corrugated steel-concrete composite girders (PCSCCG) is more prominent due to its low torsional stiffness, which is therefore crucial to be clarified for safe design. This paper proposed a theoretical model based on the combined actions softened-membrane model (CA-SMM) to predict the torsional response of PCSCCG. The equilibrium, compatibility and constitutive equations were established to consider the characteristics of corrugated steel webs (CSW) and prestressing effect, where a reasonable shear strain assumption was presented to determine the force behavior of concrete slabs and CSW, and the thickness of shear flow in concrete slabs was corrected. An optimized algorithm using the gradient descent method was established to improve the insufficiency and stability. Based on this, a simplified design method was proposed to rapidly evaluate the torque and twist of PCSCCG. Finally, the feasibility of the proposed model and simplified design method was verified by available tests. The superiority of the analytical model in predicting the full torsional performance of PCSCCG was proved, and the reasonability and simplicity of the simplified method in capturing the cracking, yield, and ultimate torques and twists were observed.

关键词： Composite girder Corrugated steel webs Combined actions softened-membrane model optimized algorithm Simplified design method

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Improved softened truss model for prestressed concrete composite box girders with corrugated steel webs under pure torsion

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ENGINEERING STRUCTURES 2024年 302卷

作者： Zhang, Hao Zhao, Qiu Xiao, Feng Chen, Yiyan Yang, Xiaoqiang Fuzhou Univ Coll Civil Engn Fuzhou 350108 Peoples R China

This paper aimed at developing a theoretical model for prestressed composite box girders with corrugated steel webs (CSW) under pure torsion, based on the combined action softened truss model (CA-STM). The equilibrium equations and materials' constitutive laws were modified, considering the relationship between the initial stress and strain generated by prestressing. According to the yield state of the CSW, proper shear flow conditions were also introduced to describe the deformation coordination relationship between the CSW and concrete slabs. The effect of the width of cantilever slabs on the torsional performance of composite box girders was investigated. An optimized algorithm was employed to solve the CA-STM, resulting in a more efficient and stable solution procedure. The validity of the model was confirmed through the available experimental data. Results showed that the prediction accuracy of the improved CA-STM for depicting entire torsional behavior is great, when considering the reasonable shear strain relationship and modified initial torque calculation formula.

关键词： Corrugated steel webs Pure torsion Prestressed concrete composite box girder Combined action softened truss model optimized algorithm

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Improved softened truss model of prestressed concrete box girders subjected to combined bending and torsion

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ADVANCES IN STRUCTURAL ENGINEERING 2024年第6期27卷 940-961页

作者： Zhang, Hao Zhao, Qiu Xiao, Feng Chen, Yiyan Yang, Xiaoqiang Fuzhou Univ Coll Civil Engn Fuzhou Peoples R China Hong Kong Polytech Univ Dept Civil & Environm Engn Hong Kong Peoples R China Hong Kong Polytech Univ Dept Civil & Environm Engn Hung Hom Kowloon 1 Yucai Rd Hong Kong 999077 Peoples R China

Prestressed concrete (PC) box girder is an innovative structure that is widely used in large-span bridges. Under eccentric loads such as vehicles, PC girders are inevitably under combined bending and torsion. To study its bending-torsional behavior, a refined full-range analysis model based on the combined action softening truss model (CA-STM) was proposed, where a simple and effective solution procedure and failure criteria were provided. The equilibrium equation, initial estimation equation for torque, and material constitutive model were modified by considering the prestressing effect to improve the CA-STM. An optimized algorithm was also employed to simplify the solution procedure instead of the traditional trial-and-error method, thus increasing the solution rate and stability. The theoretical curves predicted from the improved CA-STM exhibited great agreement with the available experimental results, and the predicted cracking and ultimate loads were also close to the experimental values. Hence, the improved CA-STM can reasonably predict the full-range mechanical response and failure modes of PC box girders subjected to combined bending and torsion, which provides great support to the design evaluation of such bridges.

关键词： bending-torsional behavior prestressed concrete torsional full-range analysis combined action softening truss model optimized algorithm failure criteria

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Target-oriented Q-compensated reverse-time migration by using optimized pure-mode wave equation in anisotropic media

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Petroleum Science 2023年第2期20卷 866-878页

作者： Shi-Gang Xu Qian-Zong Bao Zhi-Ming Ren Chang'an University School of Geological Engineering and GeomaticsDepartment of GeophysicsXi'anShaanxi710064China National Engineering Research Center of Offshore Oil and Gas Exploration Beijing100028China

Research on seismic anisotropy and attenuation plays a significant role in exploration geophysics. To enhance the imaging quality for complicated structures, we develop several effective improvements for anisotropic attenuation effects in reverse-time migration (Q-RTM) on surface and vertical seismic profiling (VSP) acquisition geometries. First, to suppress pseudo-shear wave artifact and numerical instability of the commonly used anisotropic pseudo-acoustic wave equations, an optimized pure P-wave dispersion relation is derived and the corresponding pure-mode wave equation is solved by combining the finite-difference and Possion methods. Second, a simplified anisotropic pure-mode visco-acoustic wave equation (PVAWE) based on standard linear solid model is established. Third, a time-dispersion correlation strategy is applied to improve the modeling accuracy. Fourth, we extend a target-oriented scheme to anisotropic attenuated modeling and imaging. Instead of the conventional wavefield modeling and RTM, the proposed approach can extract available wavefield information near the target regions and produce high imaging resolution for target structures. Last, both anisotropic surface and VSP Q-RTMs are executed by combining optimized PVAWE, time-dispersion correlation and target-oriented algorithm. Modeling examples demonstrate the advantages of our schemes. Moreover, our modified Q-compensated imaging workflow can be regarded as a supplement to the classical anisotropic RTM.

关键词： Anisotropy Attenuation Reverse-time migration Wave equation optimized algorithm Target-oriented

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Prediction and uncertainty quantification of compressive strength of high-strength concrete using optimized machine learning algorithms

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STRUCTURAL CONCRETE 2022年第6期23卷 3772-3785页

作者： Han, Bing Wu, Yanqi Liu, Lulu Xinyang Coll Sch Civil Engn Xinyang Peoples R China Southeast Univ Sch Civil Engn Nanjing Peoples R China Cent South Univ Sch Civil Engn Changsha Peoples R China

Compressive strength is considered to be one of the most important mechanical properties of high-strength concrete (HSC). In this study, three machine learning models, ELM, PSO-ANN, and GS-SVR were employed to predict the compressive strength of HSC using 681 data records. The five ingredients and the compressive strength of HSC were regarded as input variable features and output target, respectively. Results indicated that the GS-SVR model showed the best performance in forecasting with the R of 0.992, MAPE of 0.016, RMSE of 1.241, MAE of 0.842, and RRMSE of 0.024, which could be an alternative candidate for strength prediction. Additionally, a sensitivity analysis was performed within the GS-SVR model to achieve an in-depth examination of the effect of each single input variable on the compressive strength. The sensitivity of input variables demonstrated that the water is the most sensitive parameter to the compressive strength of HSC, while the superplasticizer is less sensitive. The research of this paper can provide reference and guidance for concrete design and construction.

关键词： high-strength concrete machine learning optimized algorithm predict uncertainty quantification

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