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Group decision making based on relative projection between fuzzy preference relations

COMPUTERS & INDUSTRIAL ENGINEERING 2023年第1期184卷

作者： Liu, Zu-Lin Liu, Fang Zhang, Jia-Wei Chen, Xiao-Hong Guangxi Univ Sch Business Nanning 530004 Guangxi Peoples R China Guangxi Univ Sch Math & Informat Sci Nanning 530004 Guangxi Peoples R China Beibu Gulf Univ Coll Sci Qinzhou 535011 Guangxi Peoples R China

Group decision making (GDM) has been widely focused on for coping with the complexity of a practical decision making problem. This paper proposes a relative projection-driven GDM model with fuzzy preference relations (FPRs). First, a novel additive consistency index of FPRs is constructed using the variance of relative projections between column/row vectors in two FPRs, which is called the relative projection variance consistency index (RPVCI). The thresholds of RPVCI for FPRs with acceptable additive consistency (AAC) are calculated using the simulation method. For improving consistency of FPRs, a convergent iteration algorithm is constructed by equipping subjective and objective adjustment parameters. Second, the group consensus level is captured using relative projections of individual FPRs on the collective one. An iteration model is reported to optimize the consensus degree by combining the weights of experts with a comprehensive adjustment coefficient that depends on both subjective and objective factors. Third, a novel GDM algorithm is proposed by integrating the two proposed iteration models. Comparisons with some existing models are offered by carrying out a case study to show the novelty and advantage of the proposed GDM model.

关键词： Group decision making (GDM) Fuzzy preference relation (FPR) Relative projection Consistency and consensus iteration algorithm

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An undetermined coefficient problem for a fractional diffusion equation

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INVERSE PROBLEMS 2016年第1期32卷 015011-015011页

作者： Zhang, Zhidong Texas A&M Univ Dept Math College Stn TX 77843 USA

We consider a fractional diffusion equation (FDE) (C)D(t)(alpha)u = a(t)u(xx) with an undetermined time-dependent diffusion coefficient a(t). Firstly, for the direct problem part, we establish the existence, uniqueness and some regularity properties of the weak solution for this FDE with a fixed a(t). Secondly, for the inverse problem part, in order to recover a(t), we introduce an operator and show its monotonicity. With this property, we establish the uniqueness of a(t) and create an efficient reconstruction algorithm to recover this coefficient.

关键词： fractional diffusion fractional inverse problem reconstruct diffusion coefficient uniqueness monotonicity iteration algorithm

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L1 model-driven recursive multi-scale denoising network for image super-resolution

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KNOWLEDGE-BASED SYSTEMS 2021年 225卷 107115-107115页

作者： Sun, Zhongfan Zhao, Jianwei Zhou, Zhenghua Gao, Qingqing China Jiliang Univ Coll Sci Dept Informat Sci & Math Hangzhou 310018 Peoples R China Nanjing Univ State Key Lab Novel Software Technol Nanjing 210093 Peoples R China

Most existing deep learning based single-image super-resolution (SISR) methods mainly improve the reconstruction performances from the perspective of data-driven, i.e., widening or deepening the networks according to the huge scale of the training data. However, it will bring a huge amount of weights and biases, and cost the expensive computations. Recently, some people have proposed a new frame for designing the deep networks according to the algorithms deduced from the l(2)-optimization problem. But they did not consider the case with outliers. Since l(1)-norm can describe the sparsity of the outliers better than l(2)-norm, we propose an effective deep network designed according to the new algorithm deduced from the l(1)-optimization problem. In our proposed method, an effective iterative algorithm for the l(1) reconstructed optimization problem is deduced based on the split Bregman algorithm, majorization-minimization algorithm, and soft thresholding operator. Then according to the deduced iterative algorithm, an effective deep network, named l(1) Model-Driven Recursive Multi-Scale Denoising Network (l(1)-MRMDN), is designed. Due to the iteration form of the deduced algorithm, the proposed l(1)-MRMDN contains an inner recursion and an outer recursion. Therefore, our proposed method can not only relieve its sensitiveness to the outliers because of the l(1) data fidelity term, but also avoid designing the deep network blindly via the guidance of prior knowledge. Extensive experimental results illustrate that our proposed method is superior to some related popular SISR methods. (C) 2021 Elsevier B.V. All rights reserved.

关键词： Super-resolution Deep learning l(1) model-driven iteration algorithm Denoising network Majorization-minimization algorithm Soft thresholding operator

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An improved meshing stiffness calculation algorithm for gear pair involving fractal contact stiffness based on dynamic contact force

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EUROPEAN JOURNAL OF MECHANICS A-SOLIDS 2022年 94卷 1页

作者： Yu, Xin Sun, Yunyun Li, Hongguang Wu, Shijing Wuhan Univ Sch Power & Mech Engn Wuhan 430072 Peoples R China Shanghai Jiao Tong Univ State Key Lab Mech Syst & Vibrat Shanghai 200240 Peoples R China

The contact stiffness, which is under effects of topography at tooth meshing surface, is determined by the dynamic contact force from the holistic meshing behavior of gears. However, in previous literature, the comprehensive effect of contact force on contact stiffness is often replaced by meshing force, which results in the mismatch between contact stiffness and meshing force. To precisely model contact stiffness and meshing stiffness of gear pair, in this paper, fractal contact stiffness model is first established based on the length scale of microscopic asperities, by which the inherent nonlinear relationship between contact force and contact stiffness is revealed. Subsequently, the improved convergence algorithm based on static and dynamic deformation is applied to calculate the actual contact force. Then the contact stiffness and dynamic response of the system are solved. Based on the proposed method involving fractal contact stiffness, the influences of surface roughness are investigated. The calculation results are also compared with those of traditional method, which reveal that dynamic contact force is irreplaceable in the stiffness modeling.

关键词： Fractal method Contact stiffness Contact force iteration algorithm

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Fast γ Photon Imaging for Inner Surface Defects Detecting

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SENSORS 2021年第23期21卷 8134页

作者： Yao, Min Luo, Guangdong Zhao, Min Guo, Ruipeng Liu, Jian Nanjing Univ Aeronaut & Astronaut Coll Automat Engn Nanjing 210016 Peoples R China Minist Ind & Informat Technolog Key Lab Nondestruct Detect & Monitoring Technol High Spee Nanjing 210016 Peoples R China

Only a few effective methods can detect internal defects and monitor the internal state of complex structural parts. On the basis of the principle of PET (positron emission computed tomography), a new measurement method, using gamma photon to detect defects of an inner surface, is proposed. This method has the characteristics of strong penetration, anti-corrosion and anti-interference. With the aim of improving detection accuracy and imaging speed, this study also proposes image reconstruction algorithms, combining the classic FBP (filtered back projection) with MLEM (maximum likelihood expectation Maximization) algorithm. The proposed scheme can reduce the number of iterations required, when imaging, to achieve the same image quality. According to the operational demands of FPGAs (field-programmable gate array), a BPML (back projection maximum likelihood) algorithm is adapted to the structural characteristics of an FPGA, which makes it feasible to test the proposed algorithms therein. Furthermore, edge detection and defect recognition are conducted after reconstructing the inner image. The effectiveness and superiority of the algorithm are verified, and the performance of the FPGA is evaluated by the experiments.

关键词： positron emission computed tomography field-programmable gate array iteration algorithm internal defect detection image reconstruction

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Application of Microwave Transmission Sensors for Water Cut Metering under Varying Salinity Conditions: Device, algorithm and Uncertainty Analysis

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SENSORS 2022年第24期22卷 9746页

作者： Zuo, Kai Hong, Yi Qi, Haitao Li, Yi Li, Baolong China Univ Petr Coll Safety & Ocean Engn Beijing 102249 Peoples R China CNOOC EnerTech Drilling & Prod Co Tianjin 300452 Peoples R China CNOOC Res Inst Co Ltd Beijing 100010 Peoples R China Tsinghua Univ Tsinghua Shenzhen Int Grad Sch Shenzhen 518055 Peoples R China

The measurement of water cut in crude oil is an essential procedure in petroleum production and it is desirable to obtain these data through an automatic and real-time method. Microwave sensors can be used for the task, and they are safe, robust and can cover the whole water cut range. However, they are relatively susceptible to the water conductivity and temperature, and the algorithms for addressing these problems are still rare in the literature. In this paper, a microwave transmission sensor that can measure the water cut under varying salinity conditions is proposed, and the algorithm for solving the water cut and salinity simultaneously with the measured amplitude and phase is described in detail. Experiments under different water cut and salinity conditions are conducted, and the results are used to verify the model and algorithm. Finally, a simplified and fast method for uncertainty analysis is proposed and applied to the iteration algorithm under test conditions. It can be concluded that accuracy higher than 95% in the water cut measurements can be expected under the 0 similar to 100% water cut range, and an error of about 10% in the water conductivity is achievable under water-continuous flow conditions. The uncertainty analysis shows that the calculated water cut and salinity results are negatively correlated, and the water salinity uncertainty tends to be larger than the water cut uncertainty. When the water salinity is high, the water cut uncertainty tends to be high whereas the water salinity uncertainty tends to be low.

关键词： microwave sensors microwave transmission line plane wave theory iteration algorithm uncertainty analysis

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A novel iterative method for simultaneously conjugate matching of N-port networks

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MICROWAVE AND OPTICAL TECHNOLOGY LETTERS 2024年第7期66卷

作者： Fu, Mingye Dong, Ruibing Chinese Acad Sci GBA Branch Aerosp Informat Res Inst Guangzhou 510700 Peoples R China Guangdong Prov Key Lab Terahertz Quantum Electroma Guangzhou Peoples R China

In this paper, a novel iterative method is proposed to find the matching impedances for all-port simultaneously conjugate matching of N-port networks. This method takes advantages of the reciprocal and lossless features of the matching network, which leads to the unitary and symmetric properties of its S matrix. As a result, the computing complexity of this proposed method is analyzed and proved to be very efficiently reduced compared to previously reported methods. A two-port network, two three-port networks, a ten-port network, and a four-port 2 x 2 antenna array are presented to demonstrate the efficiency of the proposed method.

关键词： conjugate matching iteration algorithm multi-port matching

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A Wet Gas Metering System Based on the Extended-Throat Venturi Tube

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SENSORS 2021年第6期21卷 2120-2120页

作者： Xue, Haobai Yu, Peining Zhang, Maomao Zhang, Haifeng Wang, Encheng Wu, Guozhu Li, Yi Zheng, Xiangyuan Tsinghua Univ Tsinghua Shenzhen Int Grad Sch Shenzhen 518055 Peoples R China Shenzhen Inst Informat Technol Shenzhen 518172 Peoples R China Res Inst Tsinghua Guangzhou 510700 Peoples R China SINOPEC Wenliu Oil Prod Plant Zhongyuan Oilfield Puyang 457001 Peoples R China Shenzhen LeEngSTAR Technol Co Ltd Shenzhen 518055 Peoples R China

Although the use of a classical Venturi tube for wet gas metering has been extensively studied in the literature, the use of an extended-throat Venturi (ETV) tube has rarely been reported since its first proposal by J. R. Fincke in 1999. The structure of an ETV is very simple, but due to the complexity of multiphase flow, its theoretical model has not been fully established yet. Therefore, in this paper theoretical models have been developed for the convergent and throat sections of an ETV, and the gradients of front and rear differential pressures are derived analytically. Several flowrate algorithms have been proposed and compared with the existing ones. Among them, the iteration algorithm is found to be the best. A reasonable explanation is provided for its performance. The relationship between the differential pressure gradient and the flowrate relative error is also studied, such that the relative error distributions varying with ETV measured flowrates can be derived. The gas flowrate error of ETV increases with the liquid content whilst the liquid flowrate error of ETV decreases with the liquid content, and the relative errors of liquid flowrate are generally 2 to 3 times larger than that of the gas flowrate. Finally, the ETV tends to be more accurate than the classical Venturi tube. The ETV can be designed more compact under the same signal intensity due to its significantly higher velocity in the throat section.

关键词： extended-throat Venturi tube ETV classical Venturi tube gas over-reading wet gas metering iteration algorithm relative error distribution

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On simultaneous factoring of a polynomial

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Journal of Small Business - Canada 1992年第3期30卷 51-61页

The well-known Durand-Kerner method for simultaneous rootfinding for a polynomial was generalized by Grau for simultaneous factoring of a polynomial. In this note the third order method of Maehly, Ehrlich and Aberth for simultaneous rootfinding of polynomial zeros is generalized for simultaneous factoring of a polynomial in total and single-step mode. The second aim of this note is the algebraic description of the mentioned algorithms such that the euklidian algorithm is applied for evaluating the algorithms. Numerical examples are included.

关键词： Polynomial zeros iteration algorithm Newton-Raphson's method Newton-Jacobi's method simultaneous methods single step methods factorization of polynomials

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A Biproportional Construction algorithm for Correctly Calculating Fourier Series of Aperiodic Non-Sinusoidal Signal

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Engineering（科研） 2021年第10期13卷 503-525页

作者： Zicheng Li Mingwei Ren Zhaoling Chen Guohai Liu School of Electrical and Information Engineering Jiangsu University Zhenjiang China

The Fourier series (FS) applies to a periodic non-sinusoidal function satisfying the Dirichlet conditions, whereas the being-processed function in practical applications is usually an aperiodic non-sinusoidal signal.... 详细信息

The Fourier series (FS) applies to a periodic non-sinusoidal function satisfying the Dirichlet conditions, whereas the being-processed function

in practical applications is usually an aperiodic non-sinusoidal signal. When

is aperiodic, its calculated FS is not correct, which is still a challenging problem. To overcome the problem, we derive a direct calculation algorithm, a constant iteration algorithm, and an optimal iteration algorithm. The direct calculation algorithm correctly calculates its Fourier coefficients (FCs)

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