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Joints mechanical characteristics of prefabricated subway station considering bending stiffness difference

JOURNAL OF CONSTRUCTIONAL STEEL RESEARCH 2024年 222卷

作者： Jiang, Kai Huang, Linchong Du, Fenghua Shen, Jun Liang, Yu Zhang, Yanli Sun Yat Sen Univ Sch Aeronaut & Astronaut Shenzhen Campus Shenzhen 518107 Peoples R China Sun Yat Sen Univ Sch Civil Engn Zhuhai 519000 Peoples R China China Railway 14th Bur Grp Co Ltd Jinan 250101 Peoples R China Shenzhen Univ Key Lab Coastal Urban Resilient Infrastruct Minist Educ Shenzhen 518060 Peoples R China

In prefabricated subway stations, the presence of joints leads to an uneven circumferential distribution of structural stiffness. However, there has been limited research focusing on the variability in bending stiffness of joints so far. Therefore, this paper proposes a theoretical framework to study deformation characteristics considering the differences in bending stiffness. This study aim to analyze the deformation characteristics of prefabricated structures, with a specific focus on the impact of variations in bending stiffness on the overall structural behavior. The research scope includes the calculation methods for the bending stiffness of joints, predicting maximum settlement of the top plate, and analyzing the influence of key parameters such as joint positions, geometric shapes, and dimensions, overburden density gamma, lateral earth pressure coefficient lambda, overburden thickness hf, and concrete density rho on the joint bending stiffness. Results validate the reliability of the proposed method for calculating joint bending stiffness and demonstrate the key factors contributing to differences in bending stiffness.

关键词： Bending stiffness iterative algorithm Unit load method Vault settlement prediction Mortise-tenon joint

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Pretension design method for cable-beam structure

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JOURNAL OF ADVANCED MECHANICAL DESIGN SYSTEMS AND MANUFACTURING 2016年第1期10卷

作者： You, Guoqiang Yang, Pei Zhang, Jie Xian FANYI Univ Sch Technol & Engn Taiyigong St Xian 710105 Peoples R China Xidian Univ Sch Electromech Engn South Taibai Stree Xian 710071 Peoples R China

A pretension design method is proposed for the cablenet system of large span cable-beam structure. This method can improve computational efficiency of pretension design under influence of beams' deformations. In this method, cablenet system is divided into two parts-inner cablenet and edge cablenet. Inner cablenet is a pure cablenet area, its optimal pretension distribution can be easily found by using balance matrix analysis method. Edge cablenet is the other cablenet area connected with beams, and for this cablenet system, an iterative calculation combined with balance matrix analysis method and nonlinear finite element method is used to calculate its reasonable pretension distributions. In the iteration process, the shape of edge cablenet is iteratively updated according to displacements of connection joints between edge cablenet and beams, and based on these shape changes, pretension distributions of edge cablenet is recalculated iteratively. And by using this method, influence of beams' deformations can be added to cablenet pretension design. Because above complicated iterative calculation is just limited to the edge cablenet, scale of nonlinear finite element calculation in the iteration will be much smaller than calculation for the whole cable-beam structure, and the efficiency and accuracy of this calculation can be also improved at the same time. At last, this method is programmed for a numerical example, and the results indicate that the method is feasible.

关键词： Cable-beam structure Pretension distribution Balance matrix Nonlinear finite element method iterative algorithm

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A robust rank aggregation method for malicious disturbance based on objective credit

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APPLIED SOFT COMPUTING 2024年 167卷

作者： Chen, Dongmei Xiao, Yu Zhu, Huan Deng, Ye Wu, Jun Beijing Normal Univ Fac Arts & Sci Dept Syst Sci Zhuhai 519087 Peoples R China Beijing Normal Univ Sch Syst Sci Beijing 100875 Peoples R China Univ Granada Andalusian Res Inst Data Sci & Computat Intelligen Dept Comp Sci & AI Granada 18071 Spain Beijing Normal Univ Int Acad Ctr Complex Syst Zhuhai 519087 Peoples R China

Rank aggregation is a task of combining individual rankings into a consensus, which has widespread applications in many areas, ranging from social choice to information retrieval. As some users may have incentives to disrupt the aggregated ranking for enormous benefits, making rank aggregation methods robust to malicious disturbance becomes a crucial challenge. In this study, we propose a robust rank aggregation method based on objective credit. The underlying idea is that a consensus ranking is obtained by combining multiple input rankings with users' credit, while users' credit is reflected by the differences between their input rankings and the consensus ranking. This idea motivates a novel iterative algorithm, which iteratively updates a consensus ranking weighted by users' credit and modifies users' credit by measuring the differences from a consensus ranking until all credit converges. In this way, the algorithm objectively assigns different credit to users, leading to amore reliable aggregated ranking. Extensive experiments on synthetic and real data demonstrate the superior performance of our method over state-of-the-art baselines.

关键词： Rank aggregation Malicious disturbance Robustness Credit feedback mechanism iterative algorithm

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Selective image-sharpness enhancement by coupled nonlinear reaction-diffusion time-evolution equations and its application to suppression of breathing distortions in moving pictures

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ELECTRONICS AND COMMUNICATIONS IN JAPAN PART III-FUNDAMENTAL ELECTRONIC SCIENCE 2004年第5期87卷 33-47页

作者： Saito, T Satsumabayashi, J Komatsu, T Kanagawa Univ Fac Engn Yokohama Kanagawa 2218686 Japan

The authors describe a technique for selectively sharpening only edges that were blurred due to various causes without making interference factors such as random noise more conspicuous. The selective sharpening technique described in this paper is implemented as an iterative updating nonlinear algorithm obtained by discretizing a type of nonlinear reaction-diffusion time-evolution equations. The update terms of this algorithm consist of a quadratic nonlinear smoothing term, reaction term, and overshooting term. By performing quantitative evaluation experiments, the authors showed that the proposed technique has significantly better selective sharpness enhancement capabilities than existing sharpness enhancement techniques such as the peaking method. in addition, the authors introduced a processing parameter adaptive control method in the proposed technique and applied it to the suppression of breathing distortions in video sequences. Breathing distortions, which are video sequence distortions that often appear in old films, are time-varying blurring distortions that occur due to temporal variations of the focus. (C) 2004 Wiley Periodicals, Inc.

关键词： nonlinear partial differential equations nonlinear algorithm iterative algorithm time-varying blurring

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An iterative model-free feature screening procedure: Forward recursive selection

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KNOWLEDGE-BASED SYSTEMS 2022年 246卷

作者： Xia, Siwei Yang, Yuehan Civil Aviat Flight Univ China Sch Sci Deyang Peoples R China Cent Univ Finance & Econ Sch Stat & Math Beijing Peoples R China

Many researchers have studied the combinations of machine learning techniques and traditional statistical strategies, and proposed effective procedures for complicated data sets. Yet, there is still some lack of running time and prediction accuracy. In this paper, we propose an iterative feature screening procedure, named forward recursive selection. We combine the random forest and forward selection to address the model-based limitations and the related requirements. We also use the forward strategy with a limited number of iterations to improve the computational efficiency. To provide the theoretical guarantees of this method, we calculate functions of the permutation importance of this algorithm in different models and data with group structures. Numerical comparisons and empirical analysis support our results, and the proposed procedure works well. (c) 2022 Elsevier B.V. All rights reserved.

关键词： Random forest Forward selection iterative algorithm Statistical modeling

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Fast iterative reconstruction for photoacoustic tomography using learned physical model: Theoretical validation

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PHOTOACOUSTICS 2023年 29卷 100452页

作者： Hsu, Ko-Tsung Guan, Steven Chitnis, Parag, V George Mason Univ Dept Bioengn Fairfax VA 22030 USA

iterative reconstruction has demonstrated superior performance in medical imaging under compressed, sparse, and limited-view sensing scenarios. However, iterative reconstruction algorithms are slow to converge and rely heavily on hand-crafted parameters to achieve good performance. Many iterations are usually required to reconstruct a high-quality image, which is computationally expensive due to repeated evaluations of the physical model. While learned iterative reconstruction approaches such as model-based learning (MBLr) can reduce the number of iterations through convolutional neural networks, it still requires repeated evaluations of the physical models at each iteration. Therefore, the goal of this study is to develop a Fast iterative Reconstruction (FIRe) algorithm that incorporates a learned physical model into the learned iterative reconstruction scheme to further reduce the reconstruction time while maintaining robust reconstruction performance. We also propose an effi-cient training scheme for FIRe, which releases the enormous memory footprint required by learned iterative reconstruction methods through the concept of recursive training. The results of our proposed method demon-strate comparable reconstruction performance to learned iterative reconstruction methods with a 9x reduction in computation time and a 620x reduction in computation time compared to variational reconstruction.

关键词： Photoacoustic tomography iterative algorithm Deep learning Image reconstruction Learned forward operator Neural operator

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Reconstruction of temperature field in different fire stages of electrical and mechanical equipment room based on acoustic CT

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JOURNAL OF LOSS PREVENTION IN THE PROCESS INDUSTRIES 2024年 92卷

作者： Qin, Hengjie Chai, Lingling Yao, Haowei Lou, Zhen Wen, Jiangqi Zhengzhou Univ Light Ind Coll Bldg Environm Engn Zhengzhou 450001 Peoples R China Zhengzhou Univ Light Ind Zhengzhou Key Lab Elect Power Fire Safety Zhengzhou 450001 Peoples R China

Acquiring and visualizing temperature data in real time in the event of a fire in an electrical and mechanical equipment room is of great significance. It can be applied to early fire detection and monitoring, help rescuers quickly understand the fire situation, develop effective fire extinguishing and evacuation plans, and provide valuable data support for subsequent accident investigation. Acoustic computed tomography (CT) temperature measurement technology has the benefits of high precision, non-contact, real-time and global, in order to explore the applicability of this technology in the acquisition of details about temperature in the fire scene of electrical and mechanical equipment room, this paper carries out the following research. A numerical model of the fire in the electrical and mechanical equipment room is constructed on the basis of fire dynamics simulator (FDS), and the basic temperature data is obtained. The large ill-conditioned matrix equation of acoustic flight is constructed under a variety of mesh division schemes, and the Simultaneous Algebraic Reconstruction Technique (SART) is used to figure it out. Then we accomplish the temperature field reconstruction of the electrical and mechanical equipment room in different fire stages. The effect of reconstruction is evaluated through the analysis of the difference between the original and rebuilt data. The conclusions demonstrate that the acoustic CT temperature measurement technique can achieve reconstructing the temperature field in real time and with accuracy under the appropriate reconstruction scheme. With the rise in the quantity of grid divisions, the morphology of the reconstructed high-temperature region of the fire field is more similar to the morphology of the basic fire field within a certain range.

关键词： Acoustic CT iterative algorithm Different fire stages SART

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Wave characterisation and aberration correction using hybrid direct search

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JOURNAL OF OPTICS 2021年第8期23卷 085602-085602页

作者： Stilgoe, Alexander B. Rubinsztein-Dunlop, Halina Univ Queensland Sch Math & Phys Brisbane Qld 4072 Australia

Precise beam shaping relies on accurate characterisation of deformations in phase and amplitude of a wave as it propagates. We investigate a process where only a priori information about the relative locations of arbitrary source regions in time are known. We use the correlations between each region to obtain information about amplitude and phase to piece together a wavefunction representing the wave. We demonstrate that this method can be used to characterise a singularity in an initially unknown wavefunction and remove it using a beam shaping device. In contrast to some other techniques that assume point correlations, we can use any set of simple connected shapes as correlation regions. This leads us to believe that it has some use to beam shaping applications in multimode-fibres or in turbid media where singularities are present in the scattered light.

关键词： beam shaping aberration correction direct search iterative algorithm scattering

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algorithmS FOR SPLIT COMMON FIXED POINT PROBLEMS IN HILBERT SPACES

JOURNAL OF NONLINEAR AND VARIATIONAL ANALYSIS

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JOURNAL OF NONLINEAR AND VARIATIONAL ANALYSIS 2018年第3期2卷 273-286页

作者： Zhao, J. Zong, H. Muangchoo, K. Kumam, P. Cho, Y. J. Civil Aviat Univ China Coll Sci Tianjin 300300 Peoples R China King Mongkuts Univ Technol Thonburi Fac Sci Sci Lab BldgRoom SCL Fixed Point Lab 802 Fixed Point Res LabDept Math 126 Pracha Uthit Rd Bangkok 10140 Thailand Gyeongsang Natl Univ Dept Math Educ Jinju 660701 South Korea Gyeongsang Natl Univ RINS Jinju 660701 South Korea

In this paper, we use the dual variable to propose two algorithms for split common fixed-point problems of averaged mappings in real Hilbert spaces. Under suitable conditions, weak and strong convergence theorems are established. Finally, we give numerical experiments to illustrate the efficiency of the proposed iterative algorithms.

关键词： Split common fixed-point problem Variational inequality problem iterative algorithm Dual variable Averaged mapping

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Characterizing power control using traffic load indicator

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CHINESE JOURNAL OF ELECTRONICS 2002年第2期11卷 260-264页

作者： Zhang, WR Liu, XJ Wu, WL Agilent Technol Inc Ltd Beijing 100044 Peoples R China Beijing Univ Sci & Technol Dept Thermal Engn Beijing 100083 Peoples R China Beijing Univ Posts & Telecommun Coll Informat Engn Beijing 100876 Peoples R China

In this paper, we introduce the traffic load indicator in a cellular radio system that can be used to characterize the power control problem. The dimension of QoS (Quality of service) constraint equations can be reduced from the number of MSs (Mobile stations) to the number of base stations (BSs) in the system, and the intercell interference and total received power can be related by traffic load indicator we defined. Theoretical and simulation results show that power control by observing intercell interference can converge faster due to the smaller spectral radius than by measuring total received power.

关键词： mobile cellular system power control iterative algorithm

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