Special Issue "Mathematical Modeling and Computational Methods in Science and Engineering"

A special issue of Symmetry (ISSN 2073-8994).

Deadline for manuscript submissions: 31 January 2020.

Special Issue Editor

Prof. Dr. Juan Luis Garc´ıa Guirao
E-Mail Website
Guest Editor
Universidad Polit´ecnica de Cartagena, Escuela de Arquitectura e Ingenier´ıa de Edificaci´on, Departamento de Matem´atica Aplicada y Estad´ıstica, Campus Muralla del Mar, Hospital de Marina, 30203–Cartagena, (Regi´on de Murcia), Spain
Interests: topological dynamics; low dimensional discrete dynamical systems; periodic structure of smooth systems; algebraic topology; dynamics of Hamiltonian systems
Special Issues and Collections in MDPI journals

Special Issue Information

Dear Colleagues,

In recent years, computational mathematics, science, and engineering have turned into rapidly growing multidisciplinary areas with connections to business, economics, engineering, mathematics, and computer science through academia as well as industry to understand and solve complex problems. Applied Mathematics is currently playing an important role in scientific research. The success of mathematical modeling depends on the parallel development of efficient computational methods as well as more sophisticated mathematical models. To develop novel computational methods, an interdisciplinary approach is needed that involves a variety of methods, including aspects such as stochastics, statistics, numeric, and scientific computing. Please note that all submitted papers must be within the general scope of the Symmetry journal.

The topics of research areas covered for this Special Issue are:

  • Mathematical (biology, chemistry, economics, engineering, and physics);
  • Neural networks;
  • Optimal control problems;
  • Probability and statistics;
  • Scientific computing;
  • Soft computing;
  • System dynamics;
  • System engineering;
  • Artificial intelligence;
  • Automation;
  • Big data analytics;
  • Chaos theory, control, and robotics;
  • Circuits and networks;
  • Complexity theory;
  • Computational mechanics;
  • Information theory;
  • Symmetry.

All papers submitted to the Special Issue will be thoroughly reviewed by at least two or three independent experts. We hope that this Special Issue will bring some changes and some new useful tools and applications in different fields, and that it will enrich the scientific community for the researchers in the concerned fields.

Prof. Dr. Juan Luis Garc´ıa Guirao
Guest Editor

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All papers will be peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Symmetry is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 1400 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Published Papers (12 papers)

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Research

Open AccessArticle
Study of Indoor Ventilation Based on Large-Scale DNS by a Domain Decomposition Method
Symmetry 2019, 11(11), 1416; https://doi.org/10.3390/sym11111416 - 15 Nov 2019
Abstract
This paper presents a large-scale Domain Decomposition Method (DDM) based Direct Numerical Simulation (DNS) for predicting the behavior of indoor airflow, where the aim is to design a comfortable and efficient indoor air environment of modern buildings. An analogy of the single-phase convection [...] Read more.
This paper presents a large-scale Domain Decomposition Method (DDM) based Direct Numerical Simulation (DNS) for predicting the behavior of indoor airflow, where the aim is to design a comfortable and efficient indoor air environment of modern buildings. An analogy of the single-phase convection problems is applied, and the pressure stabilized domain decomposition method is used to symmetrize the linear systems of Navier-Stokes equations and the convection-diffusion equation. Furthermore, a balancing preconditioned conjugate gradient method is utilized to deal with the interface problem caused by domain decomposition. The entire simulation model is validated by comparing the numerical results with that of recognized experimental and numerical data from previous literature. The transient behavior of indoor airflow and its complexity in the ventilated room are discussed; the velocity and vortex distribution of airflow are investigated, and its possible influence on particle accumulation is classified. Full article
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Open AccessArticle
Dynamic Soft Sensor Development for Time-Varying and Multirate Data Processes Based on Discount and Weighted ARMA Models
Symmetry 2019, 11(11), 1414; https://doi.org/10.3390/sym11111414 - 15 Nov 2019
Abstract
To solve the soft sensor modeling (SSMI) problem in a nonlinear chemical process with dynamic time variation and multi-rate data, this paper proposes a dynamic SSMI method based on an autoregressive moving average (ARMA) model of weighted process data with discount (DSSMI-AMWPDD) and [...] Read more.
To solve the soft sensor modeling (SSMI) problem in a nonlinear chemical process with dynamic time variation and multi-rate data, this paper proposes a dynamic SSMI method based on an autoregressive moving average (ARMA) model of weighted process data with discount (DSSMI-AMWPDD) and optimization methods. For the sustained influence of auxiliary variable data on the dominant variables, the ARMA model structure is adopted. To reduce the complexity of the model, the dynamic weighting model is combined with the ARMA model. To address the weights of auxiliary variable data with different sampling frequencies, a calculation method for AMWPDD is proposed using assumptions that are suitable for most sequential chemical processes. The proposed method can obtain a discount factor value (DFV) of auxiliary variable data, realizing the dynamic fusion of chemical process data. Particle swarm optimization (PSO) is employed to optimize the soft sensor model parameters. To address the poor convergence problem of PSO, ω-dynamic PSO (ωDPSO) is used to improve the PSO convergence via the dynamic fluctuation of the inertia weight. A continuous stirred tank reactor (CSTR) simulation experiment was performed. The results show that the proposed DSSMI-AMWPDD method can effectively improve the SSM prediction accuracy for a nonlinear time-varying chemical process. The AMWPDD proposed in this paper can reflect the dynamic change of chemical process and improve the accuracy of SSM data prediction. The ω dynamic PSO method proposed in this paper has faster convergence speed and higher convergence accuracy, thus, these models correlate with the concept of symmetry. Full article
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Open AccessArticle
Optimization of Flocculation Settling Parameters of Whole Tailings Based on Spatial Difference Algorithm
Symmetry 2019, 11(11), 1371; https://doi.org/10.3390/sym11111371 - 05 Nov 2019
Abstract
In order to obtain the optimum parameters of total tailings flocculation settling, an optimization method of total tailings flocculation settling parameters based on the spatial difference algorithm was proposed. Firstly, the input and output factors of the whole tailings flocculation settling parameters are [...] Read more.
In order to obtain the optimum parameters of total tailings flocculation settling, an optimization method of total tailings flocculation settling parameters based on the spatial difference algorithm was proposed. Firstly, the input and output factors of the whole tailings flocculation settling parameters are effectively analyzed, and the relevant factors affecting the flocculation settling parameters are obtained. Secondly, the flocculation settling velocity of the whole tailings is optimized by combining the spatial difference algorithm with the mathematical symmetry algorithm, and the optimal value of the flocculation settling velocity of the whole tailings is obtained. The experimental results show that anionic flocculation has the best flocculation settling effect on the whole tailings. The optimal settlement velocity is close to the actual settlement velocity, and the error of settlement velocity is less than 3.5%. The results show that compared with the traditional method, this method is an effective method to optimize the flocculation and settlement parameters of the whole tailings. Full article
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Open AccessArticle
Statistical Criteria of Nanofluid Flows over a Stretching Sheet with the Effects of Magnetic Field and Viscous Dissipation
Symmetry 2019, 11(11), 1367; https://doi.org/10.3390/sym11111367 - 04 Nov 2019
Abstract
In this study, the heat and mass transfer characteristics of nanofluid flow over a nonlinearly stretching sheet are investigated. The important effects of axisymmetric of thermal conductivity and viscous dissipation have been included in the model of nanofluids. The Buongiorno model is considered [...] Read more.
In this study, the heat and mass transfer characteristics of nanofluid flow over a nonlinearly stretching sheet are investigated. The important effects of axisymmetric of thermal conductivity and viscous dissipation have been included in the model of nanofluids. The Buongiorno model is considered to solve the nanofluid boundary layer problem. The governing nonlinear partial differential equations have been transformed into a system of ordinary differential equations and are solved numerically via the shooting technique. The validity of this method was verified by comparison with previous work performed for nanofluids without the effects of the magnetic field and viscous dissipation. The analytical investigation is carried out for different governing parameters, namely, the Brownian motion parameter, thermophoresis parameter, magnetic parameter, Biot number, and Eckert number. The results indicate that the skin friction coefficient has a direct relationship with the Brownian motion number and thermophoresis number. Moreover, it can be seen that the Nusselt number decreases with the increase of the magnetic parameter and Eckert number. Full article
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Open AccessArticle
An Improved Pigeon-Inspired Optimisation Algorithm and Its Application in Parameter Inversion
Symmetry 2019, 11(10), 1291; https://doi.org/10.3390/sym11101291 - 15 Oct 2019
Abstract
Pre-stack amplitude variation with offset (AVO) elastic parameter inversion is a nonlinear, multi-solution optimisation problem. The techniques that combine intelligent optimisation algorithms and AVO inversion provide an effective identification method for oil and gas exploration. However, these techniques also have shortcomings in solving [...] Read more.
Pre-stack amplitude variation with offset (AVO) elastic parameter inversion is a nonlinear, multi-solution optimisation problem. The techniques that combine intelligent optimisation algorithms and AVO inversion provide an effective identification method for oil and gas exploration. However, these techniques also have shortcomings in solving nonlinear geophysical inversion problems. The evolutionary optimisation algorithms have recognised disadvantages, such as the tendency of convergence to a local optimum resulting in poor local optimisation performance when dealing with multimodal search problems, decreasing diversity and leading to the prematurity of the population as the number of evolutionary iterations increases. The pre-stack AVO elastic parameter inversion is nonlinear with slow convergence, while the pigeon-inspired optimisation (PIO) algorithm has the advantage of fast convergence and better optimisation characteristics. In this study, based on the characteristics of the pre-stack AVO elastic parameter inversion problem, an improved PIO algorithm (IPIO) is proposed by introducing the particle swarm optimisation (PSO) algorithm, an inverse factor, and a Gaussian factor into the PIO algorithm. The experimental comparisons indicate that the proposed IPIO algorithm can achieve better inversion results. Full article
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Open AccessArticle
On Energies of Charged Particles with Magnetic Field
Symmetry 2019, 11(10), 1204; https://doi.org/10.3390/sym11101204 - 26 Sep 2019
Abstract
The present paper is about magnetic curves of spherical images in Euclidean 3-space. We obtain the Lorentz forces of the spherical images and then we determine if the spherical images have a magnetic curve or not. If a spherical image has a magnetic [...] Read more.
The present paper is about magnetic curves of spherical images in Euclidean 3-space. We obtain the Lorentz forces of the spherical images and then we determine if the spherical images have a magnetic curve or not. If a spherical image has a magnetic curve, then after presenting some basic concepts about the energy of a charged particle whose trajectory is that magnetic curve and the kinetic energy of a moving particle whose trajectory is the spherical indicatrix, we find the energy of the charged particle and the kinetic energy of the moving particle. Full article
Open AccessArticle
Kinematics Modeling and Analysis of Mid-Low Speed Maglev Vehicle with Screw and Product of Exponential Theory
Symmetry 2019, 11(10), 1201; https://doi.org/10.3390/sym11101201 - 25 Sep 2019
Abstract
Maglev transportation is a new type of rail transit, whose vehicle is different from the two-bogie structure of the wheel-rail train. Generally, it consists of four to five suspension frames supporting a car body in parallel. The moving mechanism of a vehicle often [...] Read more.
Maglev transportation is a new type of rail transit, whose vehicle is different from the two-bogie structure of the wheel-rail train. Generally, it consists of four to five suspension frames supporting a car body in parallel. The moving mechanism of a vehicle often consists of hundreds of moving parts, showing a multi-rigid body system in serial-parallel structure. At present, there is no theoretical framework for systematically and accurately describing the kinematics and dynamics of the Maglev train. The design work is at the level of simple equivalent estimation or measurement from the CAD drawing, which makes the system performance analysis and optimization work unable to be carried out scientifically. Based on the theoretical framework of screw theory and exponential mapping, the forward kinematics modeling, inverse kinematics solution, transition curve modeling and computational analysis methods for the Maglev train are proposed in this paper. A systematic and accurate theoretical framework is constructed for the modeling and analysis of the motion mechanism of the Maglev train, which makes the design and analysis of the Maglev train at the scientific level. Full article
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Open AccessArticle
The Circular Hill Problem Regarding Arbitrary Disturbing Forces: The Periodic Solutions that are Emerging from the Equilibria
Symmetry 2019, 11(10), 1196; https://doi.org/10.3390/sym11101196 - 24 Sep 2019
Abstract
In this work, sufficient conditions for computing periodic solutions have been obtained in the circular Hill Problem with regard to arbitrary disturbing forces. This problem will be solved by means of using the averaging theory for dynamical systems as the main mathematical tool [...] Read more.
In this work, sufficient conditions for computing periodic solutions have been obtained in the circular Hill Problem with regard to arbitrary disturbing forces. This problem will be solved by means of using the averaging theory for dynamical systems as the main mathematical tool that has been applied in this work. Full article
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Open AccessArticle
RGB Inter-Channel Measures for Morphological Color Texture Characterization
Symmetry 2019, 11(10), 1190; https://doi.org/10.3390/sym11101190 - 20 Sep 2019
Abstract
The perception of textures is based on high-level features such as symmetry, brightness, color or direction. Texture characterization is a widely studied topic in the image processing community. The normalized volume of morphological series is used as a texture descriptor in RGB images. [...] Read more.
The perception of textures is based on high-level features such as symmetry, brightness, color or direction. Texture characterization is a widely studied topic in the image processing community. The normalized volume of morphological series is used as a texture descriptor in RGB images. However, the correlation between different color channels is not exploited with this descriptor. We propose the usage of inter-channel measures in addition to the volume, to enhance the descriptors potential to discriminate textures. The experiments show that standard texture classification techniques increase between 3%–10% in performance when using our descriptor instead of other state of the art descriptors that do not use inter-channel measures. Full article
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Open AccessArticle
Optimization of the Auxiliary-Beam System in Railway Bridge Vibration Mitigation Using FEM Simulation and Genetic Algorithms
Symmetry 2019, 11(9), 1089; https://doi.org/10.3390/sym11091089 - 31 Aug 2019
Abstract
In this paper, we present the optimization of a vibration mitigation system for railway bridges. These structures are subjected to significant moving loads, whose dynamic characteristics may produce resonance effects, compromising the integrity of the bridge and the security of the passengers if [...] Read more.
In this paper, we present the optimization of a vibration mitigation system for railway bridges. These structures are subjected to significant moving loads, whose dynamic characteristics may produce resonance effects, compromising the integrity of the bridge and the security of the passengers if the speed or the load of the train is not controlled. The study focuses on the Auxiliary Beam system. It consists of a beam located under the bridge and connected to the slab by viscous dampers. The symmetry of the problem allowed for the use of a 2D Finite Element model of the system. This model was used together with a genetic algorithm in order to evaluate the behaviour of different candidates and to optimize the design parameters: the inertia of the beam and the damper coefficient. The goal of the optimization process is to minimize the acceleration of the bridge while adding the lightest mitigation system possible. The combination of a Finite Element Model and Genetic Algorithm helps to address the complex problem and to find an optimized set of structural parameters. The system finally shows good behaviour for optimal parameters. Full article
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Open AccessArticle
Study on the Allocation of a Rescue Base in the Arctic
Symmetry 2019, 11(9), 1073; https://doi.org/10.3390/sym11091073 - 24 Aug 2019
Abstract
Risk assessment and emergency responses to ensure the safety of ships crossing the Arctic have gained tremendous attention in recent years. However, asymmetry in the probability that people will receive aid when navigating through the Arctic still exists because of the unsystematic allocation [...] Read more.
Risk assessment and emergency responses to ensure the safety of ships crossing the Arctic have gained tremendous attention in recent years. However, asymmetry in the probability that people will receive aid when navigating through the Arctic still exists because of the unsystematic allocation of rescue bases in the Arctic. At the same time, no study has proposed an overall solution to the problem of allocating rescue bases in the Arctic region to safeguard people’s interests. In this paper, we investigated the main natural factors affecting the safety of ship navigation in the Arctic based on the statistics of ship accidents in the Arctic from 1995 to 2004. The navigation risk of the Arctic was then assessed based on these natural factors, reflecting the need for rescue at all locations in the Arctic. Next, 37 cities with good infrastructure were selected among those along the Arctic as candidate locations for rescue bases. Finally, a new model was constructed based on the Set Covering Location Model, Double Covering Location Model, and P-Median Model to determine the optimal allocation of rescue bases in the Arctic. The rescue bases covered all the areas in the Arctic, and minimized cost in terms of distance and other economic factors. In addition, the constructed model ensured that two rescue bases were allocated to the areas with high navigation risk. Full article
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Open AccessArticle
Image Enhancement Using Modified Histogram and Log-Exp Transformation
Symmetry 2019, 11(8), 1062; https://doi.org/10.3390/sym11081062 - 20 Aug 2019
Abstract
An effective method to enhance the contrast of digital images is proposed in this paper. A histogram function is developed to make the histogram curve smoother, which can be used to avoid the loss of information in the processed image. Besides the histogram [...] Read more.
An effective method to enhance the contrast of digital images is proposed in this paper. A histogram function is developed to make the histogram curve smoother, which can be used to avoid the loss of information in the processed image. Besides the histogram function, an adaptive gamma correction for the histogram is proposed to stretch the brightness contrast. Moreover, the log-exp transformation strategy is presented to progressively increase the low intensity while suppressing the decrement of the high intensity. In order to further widen the dynamic range of the image, the nonlinear normalization transformation is put forward to make the output image more natural and clearer. In the experiment on non-uniform illumination images, the average contrast per pixel (CPP), root mean square (RMS), and discrete entropy (DE) metrics of the developed approach are shown to be superior to selected state-of-the-art methods. Full article
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