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  • Article
  • Open Access
12 Citations
8,287 Views
14 Pages

FPGA-Based Hardware Matrix Inversion Architecture Using Hybrid Piecewise Polynomial Approximation Systolic Cells

  • Javier Vázquez-Castillo,
  • Alejandro Castillo-Atoche,
  • Roberto Carrasco-Alvarez,
  • Omar Longoria-Gandara and
  • Jaime Ortegón-Aguilar

The hardware of the matrix inversion architecture using QR decomposition with Givens Rotations (GR) and a back substitution (BS) block is required for many signal processing algorithms. However, the hardware of the GR algorithm requires the implement...

(This article belongs to the Special Issue Approximate Computing: Design, Acceleration, Validation and Testing of Circuits, Architectures and Algorithms in Future Systems)
  • Article
  • Open Access
2 Citations
1,610 Views
22 Pages

The Right–Left WG Inverse Solutions to Quaternion Matrix Equations

  • Ivan Kyrchei,
  • Dijana Mosić and
  • Predrag Stanimirović

28 December 2024

This paper studies new characterizations and expressions of the weak group (WG) inverse and its dual over the quaternion skew field. We introduce a dual to the weak group inverse for the first time in the literature and give some new characterization...

(This article belongs to the Special Issue Exploring Symmetry in Dual Quaternion Matrices and Matrix Equations)
  • Article
  • Open Access
5 Citations
6,105 Views
18 Pages

Numerical Inverse Transformation Methods for Z-Transform

  • Illés Horváth,
  • András Mészáros and
  • Miklós Telek

10 April 2020

Numerical inverse Z-transformation (NIZT) methods have been efficiently used in engineering practice for a long time. In this paper, we compare the abilities of the most widely used NIZT methods, and propose a new variant of a classic NIZT method bas...

(This article belongs to the Special Issue Queue and Stochastic Models for Operations Research)
  • Article
  • Open Access
6 Citations
3,549 Views
25 Pages

Trajectory PHD Filter for Adaptive Measurement Noise Covariance Based on Variational Bayesian Approximation

  • Xingchen Lu,
  • Dahai Jing,
  • Defu Jiang,
  • Yiyue Gao and ,
  • Jialin Yang,
  • Yao Li,
  • Wendong Li,
  • Jin Tao and
  • Ming Liu
  • + 4 authors+ 0 author

23 June 2022

In order to solve the problem that the measurement noise covariance may be unknown or change with time in actual multi-target tracking, this paper brings the variational Bayesian approximation method into the trajectory probability hypothesis density...

(This article belongs to the Section Electrical, Electronics and Communications Engineering)
  • Article
  • Open Access
6 Citations
2,202 Views
17 Pages

21 May 2024

In geophysical inversion issues, the Jacobian matrix computation takes the greatest time, and it is the most significant factor limiting the inversion’s calculation speed. We think that the correctness of the inverse problem is determined by th...

  • Article
  • Open Access
3 Citations
5,705 Views
19 Pages

Improving Newton–Schulz Method for Approximating Matrix Generalized Inverse by Using Schemes with Memory

  • Alicia Cordero,
  • Javier G. Maimó,
  • Juan R. Torregrosa and
  • María P. Vassileva

18 July 2023

Some iterative schemes with memory were designed for approximating the inverse of a nonsingular square complex matrix and the Moore–Penrose inverse of a singular square matrix or an arbitrary m×n complex matrix. A Kurchatov-type scheme an...

(This article belongs to the Section E: Applied Mathematics)
  • Article
  • Open Access
3 Citations
2,288 Views
21 Pages

17 February 2022

Progressive iterative approximation (PIA) technique is an efficient and intuitive method for data fitting. In CAGD modeling, if the given data points are taken as initial control points, PIA process generates a series of shaping curves by adjusting t...

(This article belongs to the Special Issue Symmetry and Approximation Methods)
  • Editorial
  • Open Access
1,345 Views
2 Pages

22 July 2022

This Special Issue contains 14 articles from the MDPI journal Symmetry on the general subject area of “Special Functions and Polynomials”, written by scholars belonging to different countries of the world. A similar number of submitted ar...

(This article belongs to the Special Issue Special Functions and Polynomials)
  • Article
  • Open Access
18 Citations
3,439 Views
13 Pages

Generalized Inverses Estimations by Means of Iterative Methods with Memory

  • Santiago Artidiello,
  • Alicia Cordero,
  • Juan R. Torregrosa and
  • María P. Vassileva

18 December 2019

A secant-type method is designed for approximating the inverse and some generalized inverses of a complex matrix A. For a nonsingular matrix, the proposed method gives us an approximation of the inverse and, when the matrix is singular, an approximat...

(This article belongs to the Special Issue Selected Papers from Iterative Processes for Solving Nonlinear Problems: Convergence and Stability of ICIAM 2019 and MME&HB 2019)
  • Article
  • Open Access
3 Citations
2,684 Views
8 Pages

On High-Order Iterative Schemes for the Matrix pth Root Avoiding the Use of Inverses

  • Sergio Amat,
  • Sonia Busquier,
  • Miguel Ángel Hernández-Verón and
  • Ángel Alberto Magreñán

11 January 2021

This paper is devoted to the approximation of matrix pth roots. We present and analyze a family of algorithms free of inverses. The method is a combination of two families of iterative methods. The first one gives an approximation of the matrix inver...

(This article belongs to the Special Issue Application of Iterative Methods for Solving Nonlinear Equations)
  • Article
  • Open Access
12 Citations
4,689 Views
20 Pages

16 September 2019

The concept presented in this paper is based on previous dynamical methods to realize a time-varying matrix inversion. It is essentially a set of coupled ordinary differential equations (ODEs) which does indeed constitute a recurrent neural network (...

(This article belongs to the Special Issue Intelligent Transportation Related Complex Systems and Sensors)
  • Article
  • Open Access
450 Views
13 Pages

8 July 2026

In penetrating radar waveform inversion, the Limited-memory Broyden–Fletcher–Goldfarb–Shanno (L-BFGS) algorithm only needs to store the most recent gradients and model parameters to approximate the Hessian matrix, which effectively...

(This article belongs to the Special Issue Applications of Data Processing Techniques in Geophysical Exploration)
  • Article
  • Open Access
9 Citations
5,079 Views
19 Pages

An Improved Taylor Algorithm for Computing the Matrix Logarithm

  • Javier Ibáñez,
  • Jorge Sastre,
  • Pedro Ruiz,
  • José M. Alonso and
  • Emilio Defez

24 August 2021

The most popular method for computing the matrix logarithm is a combination of the inverse scaling and squaring method in conjunction with a Padé approximation, sometimes accompanied by the Schur decomposition. In this work, we present a Taylor serie...

(This article belongs to the Special Issue Mathematical Models and Methods in Engineering and Social Sciences)
  • Article
  • Open Access
13 Citations
10,140 Views
26 Pages

The problem of inverse kinematics is essential to consider while dealing with the robot’s mechanical structure in almost all applications. Since the solution of the inverse kinematics problem is very complex, many research efforts have been working t...

(This article belongs to the Section Industrial Robots and Automation)
  • Article
  • Open Access
31 Citations
5,251 Views
15 Pages

28 March 2020

Massive multiple-input multiple-output (M-MIMO) is a substantial pillar in fifth generation (5G) mobile communication systems. Although the maximum likelihood (ML) detector attains the optimum performance, it has an exponential complexity. Linear det...

(This article belongs to the Special Issue Information Theory and 5G/6G Mobile Communications)
  • Article
  • Open Access
1 Citations
956 Views
17 Pages

23 May 2025

Tempered fractional diffusion equations constitute a critical class of partial differential equations with broad applications across multiple physical domains. In this paper, the Crank–Nicolson method and the tempered weighted and shifted Gr&uu...

(This article belongs to the Special Issue Numerical Optimization and Algorithms: 3rd Edition)
  • Article
  • Open Access
217 Views
53 Pages

The kinematic control of manipulators has extensive applications in modern industry. Precise control enables robotic manipulators to perform diverse complex tasks, boost production efficiency/quality, and cut labor costs and safety risks. Kinematic c...

(This article belongs to the Topic Non-Linear Control and Its Applications)
  • Article
  • Open Access
1 Citations
1,392 Views
27 Pages

25 August 2025

Inverse problems have numerous important applications in science, engineering, medicine, and other disciplines. In this study, we present a numerical solution for a one-dimensional parabolic inverse problem with energy overspecification at a fixed sp...

(This article belongs to the Section Analysis of Algorithms and Complexity Theory)
  • Article
  • Open Access
404 Views
27 Pages

5 August 2026

Three-dimensional inversion of airborne transient electromagnetic (ATEM) data is computationally demanding because it requires repeated forward simulations and sensitivity calculations. Previous Krylov-subspace studies have substantially improved the...

  • Article
  • Open Access
2 Citations
1,615 Views
15 Pages

13 April 2025

The paper considers one of the possible statements of inverse problems in gravimetric and magnetometric remote sensing, proposes a new approach to its solution and formulates algorithms that implement this approach. The problem under consideration co...

(This article belongs to the Section E: Applied Mathematics)
  • Article
  • Open Access
10 Citations
4,283 Views
19 Pages

Insight into Construction of Tikhonov-Type Regularization for Atmospheric Retrievals

  • Jian Xu,
  • Lanlan Rao,
  • Franz Schreier,
  • Dmitry S. Efremenko and ,
  • Adrian Doicu and
  • Thomas Trautmann
  • + 1 author+ 0 author

1 October 2020

In atmospheric science we are confronted with inverse problems arising in applications associated with retrievals of geophysical parameters. A nonlinear mapping from geophysical quantities (e.g., atmospheric properties) to spectral measurements can b...

(This article belongs to the Section Atmospheric Techniques, Instruments, and Modeling)
  • Article
  • Open Access
5 Citations
2,996 Views
20 Pages

19 August 2022

The invariant imbedding T-matrix (IIM T-matrix) model is regarded as one of the most promising models for calculating the scattering parameters of non-spherical particles. However, the IIM T-matrix model needs to be iterated along the radial directio...

(This article belongs to the Special Issue Atmospheric and Surface Modeling, Data Assimilation, and Forecasting of Remote Sensing)
  • Article
  • Open Access
336 Views
21 Pages

4 September 2026

On resource-constrained edge hardware, fixed-point Transformer inference is constrained by GEMM kernels and non-GEMM normalization paths. In LayerNorm and Softmax, division, inverse square root, and denominator reciprocal operations complicate fixed-...

(This article belongs to the Special Issue Advanced Technologies in Signal and Image Processing)
  • Article
  • Open Access
3,495 Views
22 Pages

Computing the Matrix Logarithm with the Romberg Integration Method

  • Javier Ibáñez,
  • José M. Alonso,
  • Emilio Defez,
  • Pedro Alonso-Jordá and
  • Jorge Sastre

9 September 2023

The matrix logarithm function has applicability in many engineering and science fields. Improvements in its calculation, from the point of view of both accuracy and/or execution time, have a direct impact on these disciplines. This paper describes a...

(This article belongs to the Special Issue Numerical Optimization and Algorithms)
  • Article
  • Open Access
11 Citations
11,101 Views
17 Pages

Image Reconstruction of a Charge Coupled Device Based Optical Tomographic Instrumentation System for Particle Sizing

  • Mariani Idroas,
  • Ruzairi Abdul Rahim,
  • Robert Garnet Green,
  • Muhammad Nasir Ibrahim and
  • Mohd Hafiz Fazalul Rahiman

22 October 2010

This research investigates the use of charge coupled device (abbreviated as CCD) linear image sensors in an optical tomographic instrumentation system used for sizing particles. The measurement system, consisting of four CCD linear image sensors are...

(This article belongs to the Section Chemical Sensors)
  • Article
  • Open Access
46 Citations
4,362 Views
43 Pages

3 July 2020

We review a series of unitarization techniques that have been used during the last decades, many of them in connection with the advent and development of current algebra and later of Chiral Perturbation Theory. Several methods are discussed like the...

(This article belongs to the Special Issue Effective Field Theories - Chiral Perturbation Theory and Non-relativistic QFT)
  • Article
  • Open Access
2 Citations
467 Views
18 Pages

23 March 2026

A new version of the linear integral representation method is developed for solving inverse problems in geophysics. This approach is applied to the interpretation of anomalous time-dependent field data. The reconstruction of field elements is reduced...

(This article belongs to the Section B: Mathematics)
  • Article
  • Open Access
418 Views
22 Pages

27 August 2026

The accuracy of microseismic moment tensor inversion critically depends on the spatial configuration of surface sensor arrays, quantified by the condition number κ(G) of the dynamic response matrix. Existing optimization methods suffer from slo...

(This article belongs to the Section Environmental Sensing)
  • Article
  • Open Access
30 Citations
6,204 Views
26 Pages

26 July 2018

This paper proposes an inverse model for raindrop size distribution (DSD) retrieval with polarimetric radar variables. In this method, a forward operator is first developed based on the simulations of monodisperse raindrops using a T-matrix method, a...

(This article belongs to the Special Issue Radar Polarimetry—Applications in Remote Sensing of the Atmosphere)
  • Article
  • Open Access
645 Views
14 Pages

24 June 2026

3D magnetotelluric (MT) inversion based on the Gauss–Newton (GN) framework plays an important role in deep mineral exploration by imaging subsurface electrical conductivity structures. However, large-scale 3D MT inversion remains computationall...

(This article belongs to the Special Issue Advances in Magnetic and Electromagnetic Techniques for Mineral Exploration: Enhancing Resource Discovery, 2nd Edition)
  • Article
  • Open Access
4 Citations
1,971 Views
19 Pages

A Novel Depth-Weighting Approach Based on Regularized Downward Continuation for Enhanced Gravity Inversion

  • Zhe Qu,
  • Gang Min,
  • Zhengwei Xu,
  • Minghao Xian and ,
  • Yu Zhang,
  • Aidong She and
  • Jun Li
  • + 2 authors+ 0 author

27 March 2025

Gravity inversion plays a crucial role in mineral exploration and resource evaluation, yet conventional depth-weighting methods often impose uniform resolution across all depths and fail to effectively delineate anomaly boundaries. This study present...

(This article belongs to the Section Earth Observation Data)
  • Article
  • Open Access
4 Citations
5,248 Views
14 Pages

Improved Massive MIMO RZF Precoding Algorithm Based on Truncated Kapteyn Series Expansion

  • Xiaomei Xue,
  • Zhengquan Li,
  • Yongqiang Man,
  • Song Xing and ,
  • Yang Liu,
  • Baolong Li and
  • Qiong Wu
  • + 2 authors+ 0 author

11 April 2019

In order to reduce the computational complexity of the inverse matrix in the regularized zero-forcing (RZF) precoding algorithm, this paper expands and approximates the inverse matrix based on the truncated Kapteyn series expansion and the correspond...

(This article belongs to the Section Information and Communications Technology)
  • Article
  • Open Access
19 Citations
6,465 Views
15 Pages

2 September 2014

In the application of a micro-/nano-mechanical resonator, the position of an accreted particle and the resonant frequencies are measured by two different physical systems. Detecting the particle position sometimes can be extremely difficult or even i...

(This article belongs to the Section Physical Sensors)
  • Article
  • Open Access
41 Citations
5,147 Views
16 Pages

3 August 2018

To solve the problem of unknown state noises and uncertain measurement noises inherent in underwater cooperative navigation, a new Variational Bayesian (VB)-based Adaptive Extended Kalman Filter (VBAEKF) for master–slave Autonomous Underwater V...

(This article belongs to the Section Physical Sensors)
  • Article
  • Open Access
6 Citations
3,681 Views
8 Pages

2 January 2020

In massive multiple-input multiple-output (M-MIMO) systems, a detector based on maximum likelihood (ML) algorithm attains optimum performance, but it exhaustively searches all possible solutions, hence, it has a very high complexity and realization i...

(This article belongs to the Special Issue Information Technologies and Electronics)
  • Article
  • Open Access
1 Citations
3,906 Views
22 Pages

5 November 2024

The Luk-Ulo Melange Complex (LMC) is characterized by a chaotic assemblage of mixed rocks with a block-in-matrix fabric. The exposed blocks consist of various scattered rock types, trending in an ENE-WSW direction. In the case of Mt. Parang, the orig...

(This article belongs to the Section Geophysics)
  • Article
  • Open Access
2 Citations
1,024 Views
22 Pages

28 June 2025

This paper investigates the inverse problem of identifying a time-dependent source term in multi-term time–space fractional diffusion Equations (TSFDE). First, we rigorously establish the existence and uniqueness of strong solutions for the ass...

(This article belongs to the Special Issue Mathematical Modelling and Computational Methods in Real-World Applications)
  • Article
  • Open Access
4,577 Views
20 Pages

An Accurate Jacobian Matrix with Exact Zoeppritz for Elastic Moduli of Dry Rock

  • Xiaobo Liu,
  • Jingyi Chen,
  • Fuping Liu and
  • Zhencong Zhao

13 December 2019

Seismic velocities are related to the solid matrices and the pore fluids. The bulk and shear moduli of dry rock are the primary parameters to characterize solid matrices. Amplitude variation with offset (AVO) or amplitude variation with incidence ang...

(This article belongs to the Section Acoustics and Vibrations)
  • Article
  • Open Access
9 Citations
2,458 Views
13 Pages

Coherent Backscattering by Large Ice Crystals of Irregular Shapes in Cirrus Clouds

  • Natalia Kustova,
  • Alexander Konoshonkin,
  • Victor Shishko,
  • Dmitry Timofeev and ,
  • Anatoli Borovoi and
  • Zhenzhu Wang
  • + 1 author+ 0 author

12 August 2022

All elements of the scattering matrix have been numerically studied for particles of irregular shapes whose size is much larger than incident wavelength. The calculations are performed in the physical optics approximation for a particle size of 20 &m...

(This article belongs to the Section Atmospheric Techniques, Instruments, and Modeling)
  • Article
  • Open Access
8 Citations
3,965 Views
13 Pages

11 March 2020

For multi-user uplink massive multiple input multiple output (MIMO) systems, minimum mean square error (MMSE) criterion-based linear signal detection algorithm achieves nearly optimal performance, on condition that the number of antennas at the base...

(This article belongs to the Section Communications)
  • Article
  • Open Access
2 Citations
2,311 Views
15 Pages

24 November 2020

Stochastic processes are useful and important for modeling the evolution of processes that take different states over time, a situation frequently found in fields such as medical research and engineering. In a previous paper and within this framework...

(This article belongs to the Special Issue Computational Methods in Analysis and Applications 2020)
  • Article
  • Open Access
12 Citations
3,942 Views
15 Pages

Seismic Imaging of Complex Velocity Structures by 2D Pseudo-Viscoelastic Time-Domain Full-Waveform Inversion

  • Niloofar Alaei,
  • Mehrdad Soleimani Monfared,
  • Amin Roshandel Kahoo and
  • Thomas Bohlen

1 August 2022

In the presented study, multi-parameter inversion in the presence of attenuation is used for the reconstruction of the P- and the S- wave velocities and the density models of a synthetic shallow subsurface structure that contains a dipping high-veloc...

(This article belongs to the Special Issue Advancing Complexity Research in Earth Sciences and Geography)
  • Feature Paper
  • Article
  • Open Access
9 Citations
3,006 Views
18 Pages

High-Precision Iterative Preconditioned Gauss–Seidel Detection Algorithm for Massive MIMO Systems

  • Mushtaq Ahmad,
  • Xiaofei Zhang,
  • Imran A. Khoso,
  • Xinlei Shi and
  • Yang Qian

19 November 2022

Signal detection is a serious challenge for uplink massive multiple-input multiple-output (MIMO) systems. The traditional linear minimum-mean-squared error (MMSE) achieves good detection performance for such systems, but involves matrix inversion, wh...

(This article belongs to the Special Issue Massive MIMO Technology for 5G and Beyond)
  • Article
  • Open Access
4 Citations
1,981 Views
27 Pages

25 November 2024

This paper investigates statistical methods for estimating unknown lifetime parameters using a progressive first-failure censoring dataset. The failure mode’s lifetime distribution is modeled by the odd-generalized-exponential–inverse-Wei...

(This article belongs to the Special Issue Reliability and Risk of Complex Systems: Modelling, Analysis and Optimization)
  • Article
  • Open Access
2 Citations
3,178 Views
12 Pages

Computationally Efficient Soft Detection Schemes for Coded Massive MIMO Systems

  • Meixiang Zhang,
  • Zhi Zhang,
  • Satya Chan and
  • Sooyoung Kim

This paper presents a computationally efficient soft detection scheme for massive multiple-input multiple-output (MIMO) systems. The proposed scheme adopts joint iterative detection and decoding (JIDD) methods for their capacity limiting performances...

(This article belongs to the Special Issue Future Networks: New Advances and Challenges)
  • Article
  • Open Access
2 Citations
5,514 Views
20 Pages

We focus on inverse preconditioners based on minimizing F ( X ) = 1 − cos ( X A , I ) , where X A is the preconditioned matrix and A is symmetric and positive definite. We present and analyze gradient-type methods to minimize F ( X...

  • Article
  • Open Access
32 Citations
4,248 Views
19 Pages

9 September 2020

We develop online graph learning algorithms from streaming network data. Our goal is to track the (possibly) time-varying network topology, and affect memory and computational savings by processing the data on-the-fly as they are acquired. The setup...

(This article belongs to the Special Issue Efficient Graph Algorithms in Machine Learning)
  • Article
  • Open Access
10 Citations
5,217 Views
11 Pages

12 August 2021

In the paper, orthogonal transforms based on proposed symmetric, orthogonal matrices are created. These transforms can be considered as generalized Walsh–Hadamard Transforms. The simplicity of calculating the forward and inverse transforms is one of...

(This article belongs to the Special Issue Novel Advances of Image and Signal Processing)
  • Article
  • Open Access
23 Citations
4,670 Views
18 Pages

An Improved High-Dimensional Kriging Surrogate Modeling Method through Principal Component Dimension Reduction

  • Yaohui Li,
  • Junjun Shi,
  • Zhifeng Yin,
  • Jingfang Shen and ,
  • Yizhong Wu and
  • Shuting Wang
  • + 1 author+ 0 author

19 August 2021

The Kriging surrogate model in complex simulation problems uses as few expensive objectives as possible to establish a global or local approximate interpolation. However, due to the inversion of the covariance correlation matrix and the solving of Kr...

(This article belongs to the Special Issue Modeling and Simulation in Engineering)
  • Technical Note
  • Open Access
1,991 Views
11 Pages

On the Approximation of Precision Matrices for Wide-Swath Altimetry

  • Max Yaremchuk,
  • Christopher Beattie and
  • Gleb Panteleev

5 December 2024

New observations of ocean surface topography obtained by wide-swath satellite interferometry require new capabilities to process spatially correlated errors in order to assimilate these data into numerical models. The sea surface height (SSH) variati...

(This article belongs to the Section Environmental Remote Sensing)

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