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An analytical algorithm for assessing dynamic characteristics of a triple-tower double-cable suspension bridge

STRUCTURAL ENGINEERING AND MECHANICS 2024年第4期90卷 325-343页

作者： Zhang, Wen-ming Chen, Yu-peng Wang, Shi-han Lu, Xiao-fan Southeast Univ Key Lab Concrete & Prestressed Concrete Struct Minist Educ Nanjing 211189 Peoples R China Southeast Univ State Key Lab Safety Durabil & Hlth Operat Long Sp Nanjing 210096 Peoples R China

Triple -tower double -cable suspension bridges have increased confinement stiffness imposed by the main cable on the middle tower, which has bright application prospects. However, vertical bending and torsional vibrations of the double -cable and the girder are coupled in such bridges due to the hangers. In particular, the bending vibration of the towers in the longitudinal direction and torsional vibrations about the vertical axis influence the vertical bending and torsional vibrations of the stiffening girders, respectively. The conventional analytical algorithm for assessing the dynamic features of the suspension bridge is not directly applicable to this type of bridge. This study attempts to mitigate this problem by introducing an analytical algorithm for solving the triple -tower double -cable suspension bridge's natural frequencies and mode shapes. D'Alembert's principle is employed to construct the differential equations of the vertical bending and torsional vibrations of the stiffening girder continuum in each span. Vibrations of stiffening girders in each span are interrelated via the vibrations of the main cables and the bridge towers. On this basis, the natural frequencies and mode shapes are derived by separating variables. The proposed algorithm is then applied to an engineering example. The natural frequencies and mode shapes of vertical bending and torsional vibrations derived by the analytical algorithm agreed well with calculations via the finite element method. The fundamental frequency of vertical bending and first- and second -order torsion frequencies of double -cable suspension bridges are much higher than those of single -cable suspension bridges. The analytical algorithm has high computational efficiency and calculation accuracy, which can provide a reference for selecting appropriate structural parameters to meet the requirements of dynamics during the preliminary design.

关键词： analytical algorithm double-cable dynamic characteristics free vibration suspension bridge triple-tower

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Main Cable Shape-Finding and Live Load Response of the Suspension Bridge with Central Buckles: An analytical algorithm

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JOURNAL OF BRIDGE ENGINEERING 2023年第11期28卷

作者： Zhang, Wen-ming Shen, Xing-hang Chang, Jia-qi Southeast Univ Key Lab Concrete & Prestressed Concrete Struct Minist Educ Nanjing 211189 Peoples R China

The stiffness of suspension bridges, which are flexible systems composed of main cables and stiffening beams, is frequently increased by adding one or more pairs of central buckles in the midspan. This study examined a suspension bridge with flexible central buckles, proposing a set of analytical calculation methods for the shape-finding of the main cable under dead load and the structural deformation and internal forces under any uniform live loads. The proposed method is based on the known bridge design parameters. First, the suspender and central buckle tension of each hanging point of the stiffening beam was determined by the multipoint rigid support continuous beam method. After assigning these tensions to the suspenders and the central buckles, the multisegment catenary theory was used to derive the equation for each main cable segment in turn. The constraint equation was established through the closure condition of the height difference within the span. The equation was then transformed into an objective function to be programmatically solved, determining the completed bridge state. To determine the live load response of the bridge, the deformation and position relationships of the main cable, main beam, and bridge towers were analyzed in sequence, with known live load parameters. Five types of constraint equations were established through the conservation of the unstrained length of each main cable segment, the coordination of the force and deformation of each suspender, the coordination of the force and deformation of each central buckle, the closure of span length and height difference in each span, and the force balance of the main beam. Then, they were converted into an objective function to be programmatically solved, leading to the live load response of the structure. Finally, a case study of a suspension bridge with a main span of 1,050 m was used to verify the feasibility and effectiveness of the proposed method. The structural deformation and intern

关键词： Suspension bridge Flexible central buckle Main cable shape Uniform live load Structural deformation Internal force Constraint equation analytical algorithm

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analytical Design algorithm of Planar Inductor Layout in CMOS Technology

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IEEE TRANSACTIONS ON ELECTRON DEVICES 2008年第11期55卷 3208-3213页

作者： Hsu, Heng-Ming Chan, Kai-Yuen Chien, Hung-Chi Kuan, Han-Chien Natl Chung Hsing Univ Dept Elect Engn Taichung 40227 Taiwan

A layout design algorithm for a variable-width inductor is proposed to minimize metal resistance. For a given chip area, the proposed algorithm can rapidly design metal widths of each coil in a planar inductor due to the analytical form. Two on-chip inductors with identical chip areas and inductance are fabricated to verify the proposed method in foundry 90-nm CMOS technology. Measurement results demonstrate that the improvement of metal resistance in the proposed device is approximately 19%. The results of this paper provide an effective algorithm to design a high-Q inductor for RFIC applications.

关键词： analytical algorithm minimum resistance on-chip inductor variable width

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Deep learning-based prediction of Monte Carlo dose distribution for heavy ion therapy

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PHYSICS & IMAGING IN RADIATION ONCOLOGY 2025年 34卷 100735-100735页

作者： He, Rui Zhang, Hui Wang, Jian Shen, Guosheng Luo, Ying Zhang, Xinyang Ma, Yuanyuan Liu, Xinguo Li, Yazhou Peng, Haibo He, Pengbo Li, Qiang Chinese Acad Sci Inst Modern Phys Lanzhou 730000 Peoples R China Lanzhou Univ Sch Nucl Sci & Technol Lanzhou Peoples R China Chinese Acad Sci Key Lab Heavy Ion Radiat Biol & Med Lanzhou 730000 Peoples R China Key Lab Basic Res Heavy Ion Radiat Applicat Med Lanzhou 730000 Gansu Province Peoples R China Univ Chinese Acad Sci Beijing 100049 Peoples R China Gansu Prov Hosp Lanzhou 730000 Peoples R China Putian Lanhai Nucl Med Res Ctr Putian 351152 Peoples R China

Background and purpose: Current methods, like treatment planning system algorithms (TPSDose), lack accuracy, whereas Monte Carlo dose distribution (MCDose) is accurate but computationally intensive. We proposed a deep learning (DL) model for rapid prediction of Monte Carlo simulated dose distribution (MCDose) in heavy ion therapy (HIT). Materials and methods: We developed a DL model- the Cascade Hierarchically Densely 3D U-Net (CHD U-Net)- to predict MCDose using computed tomography images and TPSDose of 67 head-and-neck patients and 30 thorax-and-abdomen patients. We also compared the results with other proton dose DL models and TPSDose. Results: Compared to TPSDose, the gamma passing rate (GPR) improved by 16 % (1 %/1 mm). Notably, the model achieved 99 % and 97 % accuracy under clinically relevant criteria (3 %/3 mm) across the whole dose distribution in patients. For head-and-neck patients, the GPRs of the C3D and HD U-Net models in the PTV region were 97 % and 85 %, and in the body were 98 % and 97 %, respectively. For thorax-and-abdomen patients, the GPR of the C3D and HD U-Net models in the PTV region were 71 % and 51 %, and in the body were 95 % and 90 %, respectively. Conclusions: The proposed CHD U-Net model can predict MCDose in a few seconds and outperforms two alternative DL models. The predicted dose can replace TPSDose in HIT clinical process due to its MC simulation accuracy, thus improving the accuracy of dose calculation and providing a valuable reference for quality assurance.

关键词： Deep learning Heavy ion therapy Dose prediction Monte Carlo simulation analytical algorithm

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analytical tension-distribution computation for cable-driven parallel robots using hypersphere mapping algorithm

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MECHANISM AND MACHINE THEORY 2020年 145卷

作者： Geng, Xinyu Li, Meng Liu, Yufei Li, Yuanyuan Zheng, Wei Li, Zhibin China Acad Space Technol Qian Xuesen Lab Space Technol Youyi St 104 Beijing 100094 Peoples R China Chinese Acad Sci Acad Optoelect Beijing 100094 Peoples R China

Fully restrained cable-driven parallel robots (CDPRs) are known for their low moving inertia, high payload-to-weight ratio, and large workspace, and are widely used in modern industry. For the existence of redundancy, the cable tension-distribution computation is essentially an optimisation problem. To avoid the long computation time of the iterative calculation, and satisfy the real-time demands of control design and trajectory planning, this paper presents a novel measurement index of the magnitude of tensions, the tension hypersphere radius (THSR) for fully restrained CDPRs. This can be used to prevent slackness and excessive tension in the cables. Furthermore, according to non-probabilistic convex uncertainty propagation, the tensions with the minimum THSR can be calculated via an analytical formulation, in which the variables are the geometry, external wrench, and prescribed trajectory. The validity and applicability of presented tension hypersphere mapping algorithm are verified by the comparing with the results of 2-norm quadratic programming. (C) 2019 Elsevier Ltd. All rights reserved.

关键词： Cable-driven parallel robots Tension-distribution optimisation analytical algorithm Non-probabilistic theory Uncertainty propagation

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Image reconstruction algorithm for a rotating slat collimator

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MEDICAL PHYSICS 2002年第7期29卷 1406-1412页

作者： Zeng, GSL Gagnon, D Matthews, CG Kolthammer, JA Radachy, JD Hawkins, WG Univ Utah Med Imaging Res Lab Salt Lake City UT 84108 USA Philips Med Syst Inc Cleveland OH 44143 USA

A slat collimator in single photon emission computed tomography consists of a set of parallel slats. As the collimator spins, the detector measures a one-dimensional projection data set. A complete data set can be obtained by rotating the detector/collimator assembly around the object (patient) while the collimator spins continuously, The measured projection data are assumed to be weighted planar integrals of the object. This paper describes the development of an approximate three-dimensional image reconstruction algorithm for a rotating/spinning slat collimator. This algorithm is in filtered backprojection form. Computer simulations were performed to verify the effectiveness of the algorithm. (C) 2002 American Association of Physicists in Medicine.

关键词： image reconstruction filtered backprojection analytical algorithm slat collimator SPECT (single photon emission computed tomography)

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Joint registration and multi-target tracking based on labelled random finite set and expectation maximisation

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IET RADAR SONAR AND NAVIGATION 2018年第3期12卷 312-322页

作者： Li, Minzhe Jing, Zhongliang Pan, Han Dong, Peng Shanghai Jiao Tong Univ Sch Aeronaut & Astronaut Shanghai 200240 Peoples R China

A new analytical algorithm is developed to address the problem of joint sensor registration and multi-target tracking with varying target number and observation uncertainty based on the labelled random finite set (RFS) and expectation maximisation (EM). A new complete data log-likelihood function is derived with the measurement and state RFS variables, and the EM approach is employed to jointly estimate the sensor biases and target states. Moreover, a recursive implementation is provided to deal with the measurement accumulation, and the situation of the time-varying biases is handled. Since the estimates of the bias and state are analytically calculated, the performance of the proposed method is better than that of the traditional methods. The effectiveness and superiority of the proposed algorithm are verified using numerical simulations.

关键词： target tracking set theory expectation-maximisation algorithm recursive estimation joint sensor registration and multitarget tracking labelled random finite set expectation maximisation approach analytical algorithm observation uncertainty data log-likelihood function state RFS variables EM approach sensor biases estimation target state estimation measurement accumulation time-varying biases numerical simulations

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Circuit Network Model of Stator Transposition Bar in Large Generators and Calculation of Circulating Current

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IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS 2015年第3期62卷 1392-1399页

作者： Bian, Xu Liang, Yanping Harbin Univ Sci & Technol Harbin 150080 Peoples R China

Calculation of circulating current in transposition bars is important to the transposition-type design of stator windings in large generators. The circuit network model of the stator transposition bar, including only resistance and reactance parameters, is proposed in this paper, and the calculation method for parameters is given. The analytical algorithm of circulating current in stator transposition bars is proposed based on the circuit network model. Contrary to the existing calculation method for circulating current, the presented analytical algorithm is a general and fast method for different transposition types, which can avoid establishing complex 3-D models. In order to validate the proposed analytical algorithm, the strand current and circulating current of less than 540 degrees with a void transposition bar in a water-cooled turbogenerator are calculated by analytical algorithm and 3-D finite-element method.

关键词： analytical algorithm circuit network model circulating current large generator transposition bars

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Research on eddy current losses algorithm in solid rotor of high speed squirrel cage induction motor

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IET ELECTRIC POWER APPLICATIONS 2020年第6期14卷 1023-1029页

作者： Chou, Weixiang Liang, Yanping Gao, Lianlian Wang, Dongmei Harbin Univ Sci & Technol Coll Elect & Elect Engn Harbin Peoples R China

Aiming at the shortcomings of the analytical algorithm and numerical algorithm for calculating the eddy current losses in the solid rotor of high speed squirrel cage induction motor, this study proposes a semi-analytical algorithm. Based on the magnetic field of the rotor surface and Maxwell's equations, the analytical formula of this algorithm is derived. According to the law of energy conservation, the losses in rotor and rotor bars are calculated, respectively, so that the eddy current losses in the solid rotor are calculated indirectly. Taking a high speed squirrel cage induction motor as an example, the eddy current losses in the solid rotor are calculated by the semi-analytical method. The calculation result is verified by the two-dimensional transient finite-element method, and the calculation result meets the basic requirements of engineering practice.

关键词： rotors squirrel cage motors finite element analysis eddy current losses energy conservation magnetic fields Maxwell equations eddy current losses algorithm solid rotor analytical algorithm numerical algorithm semianalytical algorithm rotor surface rotor bars semianalytical method high speed squirrel cage induction motor magnetic field Maxwell equations energy conservation two-dimensional transient finite-element method

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Image reconstruction algorithm for a SPECT system with a convergent rotating slat collimator

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IEEE TRANSACTIONS ON NUCLEAR SCIENCE 2004年第1期51卷 142-148页

作者： Zeng, GL Gagnon, D Univ Utah Med Imaging Res Lab Salt Lake City UT 84108 USA Philips Med Syst Inc Cleveland OH 44143 USA

In this paper, we suggest the use of a convergent rotating slat collimator in a SPECT system that contains strip-shaped CdZnTe detectors. This CdZnTe imaging device is able to provide better energy resolution than a conventional NaI(Tl) detector. A convergent imaging geometry has a higher detection sensitivity than a parallel imaging geometry when imaging a small object. A novel design method and reconstruction technique are proposed for use in this system.

关键词： analytical algorithm convergent slat collimator filtered backprojection image reconstruction single photon emission computed tomography (SPECT)

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