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PHYSICS (625 journals)                  1 2 3 4 | Last

Showing 1 - 200 of 741 Journals sorted alphabetically
Acta Acustica     Open Access   (Followers: 4)
Acta Mechanica     Hybrid Journal   (Followers: 22)
Acta Scientifica Naturalis     Open Access   (Followers: 2)
Advanced Composite Materials     Hybrid Journal   (Followers: 75)
Advanced Electronic Materials     Hybrid Journal   (Followers: 7)
Advanced Functional Materials     Hybrid Journal   (Followers: 72)
Advanced Materials     Hybrid Journal   (Followers: 259)
Advanced Quantum Technologies     Hybrid Journal   (Followers: 3)
Advanced Science Focus     Free   (Followers: 6)
Advanced Structural and Chemical Imaging     Open Access   (Followers: 2)
Advanced Studies in Theoretical Physics     Open Access   (Followers: 5)
Advanced Theory and Simulations     Hybrid Journal   (Followers: 2)
Advances in Clinical Radiology     Full-text available via subscription   (Followers: 4)
Advances in Condensed Matter Physics     Open Access   (Followers: 5)
Advances in Geophysics     Full-text available via subscription   (Followers: 7)
Advances in High Energy Physics     Open Access   (Followers: 23)
Advances in Imaging and Electron Physics     Full-text available via subscription   (Followers: 4)
Advances in Materials Physics and Chemistry     Open Access   (Followers: 33)
Advances in Natural Sciences : Nanoscience and Nanotechnology     Open Access   (Followers: 28)
Advances in OptoElectronics     Open Access   (Followers: 7)
Advances In Physics     Hybrid Journal   (Followers: 29)
Advances in Physics : X     Open Access   (Followers: 4)
Advances in Physics Theories and Applications     Open Access   (Followers: 12)
Advances in Remote Sensing     Open Access   (Followers: 59)
Aggregate     Open Access   (Followers: 2)
AIP Advances     Open Access   (Followers: 7)
AIP Conference Proceedings     Full-text available via subscription   (Followers: 2)
American Journal of Condensed Matter Physics     Open Access   (Followers: 7)
American Journal of Signal Processing     Open Access   (Followers: 14)
Anales (Asociación Física Argentina)     Open Access  
Analysis and Mathematical Physics     Hybrid Journal   (Followers: 9)
Annalen der Physik     Hybrid Journal   (Followers: 5)
Annales Geophysicae (ANGEO)     Open Access   (Followers: 21)
Annales Henri Poincaré     Hybrid Journal   (Followers: 2)
Annals of Nuclear Medicine     Hybrid Journal   (Followers: 6)
Annals of Physics     Hybrid Journal   (Followers: 7)
Annals of West University of Timisoara - Physics     Open Access   (Followers: 1)
Annual Reports on NMR Spectroscopy     Full-text available via subscription   (Followers: 4)
Annual Review of Analytical Chemistry     Full-text available via subscription   (Followers: 12)
Annual Review of Condensed Matter Physics     Full-text available via subscription   (Followers: 3)
Annual Review of Materials Research     Full-text available via subscription   (Followers: 8)
APL Materials     Open Access   (Followers: 12)
Applied Composite Materials     Hybrid Journal   (Followers: 54)
Applied Mathematics and Physics     Open Access   (Followers: 2)
Applied Physics A     Hybrid Journal   (Followers: 15)
Applied Physics Frontier     Open Access   (Followers: 2)
Applied Physics Letters     Hybrid Journal   (Followers: 45)
Applied Physics Research     Open Access   (Followers: 5)
Applied Physics Reviews     Hybrid Journal   (Followers: 11)
Applied Radiation and Isotopes     Hybrid Journal   (Followers: 4)
Applied Spectroscopy     Full-text available via subscription   (Followers: 23)
Applied Spectroscopy Reviews     Hybrid Journal   (Followers: 4)
Archive for Rational Mechanics and Analysis     Hybrid Journal   (Followers: 2)
Asia Pacific Physics Newsletter     Hybrid Journal   (Followers: 1)
Asian Journal of Physical and Chemical Sciences     Open Access   (Followers: 2)
ASTRA Proceedings     Open Access   (Followers: 3)
Astronomy & Geophysics     Hybrid Journal   (Followers: 50)
Astronomy and Astrophysics Review     Hybrid Journal   (Followers: 39)
Atoms     Open Access   (Followers: 1)
Attention, Perception & Psychophysics     Full-text available via subscription   (Followers: 15)
Axioms     Open Access   (Followers: 1)
Bangladesh Journal of Medical Physics     Open Access  
Bauphysik     Hybrid Journal   (Followers: 1)
Biomaterials     Hybrid Journal   (Followers: 55)
Biomedical Imaging and Intervention Journal     Open Access   (Followers: 5)
Biophysical Reviews     Hybrid Journal   (Followers: 2)
Biophysical Reviews and Letters     Hybrid Journal   (Followers: 5)
BJR|Open     Open Access  
Boson Journal of Modern Physics     Open Access   (Followers: 9)
Brazilian Journal of Physics     Hybrid Journal  
Bulletin of Materials Science     Open Access   (Followers: 44)
Bulletin of Taras Shevchenko National University of Kyiv. Series: Physics and Mathematics     Open Access  
Bulletin of the Atomic Scientists     Hybrid Journal   (Followers: 7)
Bulletin of the Lebedev Physics Institute     Hybrid Journal  
Bulletin of the Russian Academy of Sciences: Physics     Hybrid Journal   (Followers: 1)
Caderno Brasileiro de Ensino de Física     Open Access  
Canadian Journal of Physics     Hybrid Journal   (Followers: 11)
Cell Reports Physical Science     Open Access  
Cells     Open Access   (Followers: 2)
CERN courier. International journal of high energy physics     Free   (Followers: 8)
Chemical Physics Impact     Full-text available via subscription  
ChemPhysMater     Full-text available via subscription  
Chinese Journal of Chemical Physics     Hybrid Journal   (Followers: 1)
Chinese Journal of Physics     Hybrid Journal   (Followers: 1)
Ciencia     Open Access  
Clinical Spectroscopy     Open Access   (Followers: 1)
Cogent Physics     Open Access  
Colloid Journal     Hybrid Journal   (Followers: 3)
Communications in Mathematical Physics     Hybrid Journal   (Followers: 2)
Communications in Numerical Methods in Engineering     Hybrid Journal   (Followers: 2)
Communications Materials     Open Access  
Communications Physics     Open Access  
Complex Analysis and its Synergies     Open Access   (Followers: 2)
Composites Part A : Applied Science and Manufacturing     Hybrid Journal   (Followers: 185)
Composites Part B : Engineering     Hybrid Journal   (Followers: 227)
Composites Part C : Open Access     Open Access   (Followers: 2)
Computational Astrophysics and Cosmology     Open Access   (Followers: 7)
Computational Condensed Matter     Open Access   (Followers: 1)
Computational Materials Science     Hybrid Journal   (Followers: 26)
Computational Mathematics and Mathematical Physics     Hybrid Journal   (Followers: 5)
Computational Particle Mechanics     Hybrid Journal   (Followers: 1)
Computer Physics Communications     Hybrid Journal   (Followers: 9)
Condensed Matter     Open Access   (Followers: 2)
Contemporary Physics     Hybrid Journal   (Followers: 26)
Continuum Mechanics and Thermodynamics     Hybrid Journal   (Followers: 8)
Contributions to Plasma Physics     Hybrid Journal   (Followers: 3)
Cryogenics     Hybrid Journal   (Followers: 62)
Current Applied Physics     Full-text available via subscription   (Followers: 4)
Current Science     Open Access   (Followers: 117)
Diagnostic and Interventional Imaging     Full-text available via subscription  
Diamond and Related Materials     Hybrid Journal   (Followers: 10)
Discrete and Continuous Models and Applied Computational Science     Open Access  
Doklady Physics     Hybrid Journal   (Followers: 1)
e-Boletim da Física     Open Access  
East European Journal of Physics     Open Access   (Followers: 1)
Edufisika : Jurnal Pendidikan Fisika     Open Access  
EDUSAINS     Open Access  
Egyptian Journal of Remote Sensing and Space Science     Open Access   (Followers: 26)
EJNMMI Physics     Open Access  
Emergent Scientist     Open Access  
Engineering Failure Analysis     Hybrid Journal   (Followers: 68)
Engineering Fracture Mechanics     Hybrid Journal   (Followers: 24)
Environmental Fluid Mechanics     Hybrid Journal   (Followers: 11)
EPJ Quantum Technology     Open Access   (Followers: 2)
EPJ Techniques and Instrumentation     Open Access  
EPJ Web of Conferences     Open Access   (Followers: 1)
EUREKA : Physics and Engineering     Open Access  
European Physical Journal - Applied Physics     Full-text available via subscription   (Followers: 19)
European Physical Journal C     Hybrid Journal   (Followers: 2)
Europhysics News     Open Access  
Experimental and Computational Multiphase Flow     Hybrid Journal  
Experimental Mechanics     Hybrid Journal   (Followers: 21)
Experimental Techniques     Hybrid Journal   (Followers: 51)
Exploration Geophysics     Hybrid Journal   (Followers: 4)
Few-Body Systems     Hybrid Journal   (Followers: 2)
Fire and Materials     Hybrid Journal   (Followers: 5)
FirePhysChem     Open Access  
Flexible Services and Manufacturing Journal     Hybrid Journal   (Followers: 2)
Fluctuation and Noise Letters     Hybrid Journal  
Fluid Dynamics     Hybrid Journal   (Followers: 27)
Fortschritte der Physik/Progress of Physics     Hybrid Journal  
Frontiers in Nanotechnology     Open Access   (Followers: 1)
Frontiers in Physics     Open Access   (Followers: 6)
Frontiers of Materials Science     Hybrid Journal   (Followers: 6)
Frontiers of Physics     Hybrid Journal   (Followers: 2)
Fusion Engineering and Design     Hybrid Journal   (Followers: 6)
Geochemistry, Geophysics, Geosystems     Full-text available via subscription   (Followers: 35)
Geografiska Annaler, Series A : Physical Geography     Hybrid Journal   (Followers: 4)
Geophysical Research Letters     Full-text available via subscription   (Followers: 167)
Giant     Open Access   (Followers: 1)
Glass Physics and Chemistry     Hybrid Journal  
Granular Matter     Hybrid Journal  
Graphs and Combinatorics     Hybrid Journal   (Followers: 4)
Gravitation and Cosmology     Hybrid Journal   (Followers: 7)
Heat Transfer - Asian Research     Hybrid Journal   (Followers: 11)
High Energy Density Physics     Hybrid Journal   (Followers: 3)
High Pressure Research: An International Journal     Hybrid Journal   (Followers: 3)
Himalayan Physics     Open Access   (Followers: 6)
IEEE Embedded Systems Letters     Hybrid Journal   (Followers: 60)
IEEE Journal of Quantum Electronics     Hybrid Journal   (Followers: 19)
IEEE Journal on Multiscale and Multiphysics Computational Techniques     Hybrid Journal  
IEEE Magnetics Letters     Hybrid Journal   (Followers: 7)
IEEE Nanotechnology Magazine     Hybrid Journal   (Followers: 45)
IEEE Reviews in Biomedical Engineering     Hybrid Journal   (Followers: 19)
IEEE Signal Processing Magazine     Full-text available via subscription   (Followers: 98)
IEEE Solid-State Circuits Magazine     Hybrid Journal   (Followers: 11)
IEEE Transactions on Autonomous Mental Development     Hybrid Journal   (Followers: 8)
IEEE Transactions on Biomedical Engineering     Hybrid Journal   (Followers: 35)
IEEE Transactions on Broadcasting     Hybrid Journal   (Followers: 11)
IEEE Transactions on Geoscience and Remote Sensing     Hybrid Journal   (Followers: 178)
IEEE Transactions on Haptics     Hybrid Journal   (Followers: 4)
IEEE Transactions on Industrial Electronics     Hybrid Journal   (Followers: 85)
IEEE Transactions on Industry Applications     Hybrid Journal   (Followers: 57)
IEEE Transactions on Learning Technologies     Full-text available via subscription   (Followers: 12)
IEEE Transactions on Quantum Engineering     Open Access   (Followers: 3)
IEEE Transactions on Services Computing     Hybrid Journal   (Followers: 5)
IEEE Transactions on Software Engineering     Hybrid Journal   (Followers: 84)
IEEE Women in Engineering Magazine     Hybrid Journal   (Followers: 12)
IEEE/OSA Journal of Optical Communications and Networking     Hybrid Journal   (Followers: 19)
IET Optoelectronics     Open Access   (Followers: 3)
Il Colle di Galileo     Open Access  
Image Analysis & Stereology     Open Access   (Followers: 1)
Imaging Science Journal     Hybrid Journal   (Followers: 3)
ImmunoInformatics     Open Access   (Followers: 1)
Indian Journal of Biochemistry and Biophysics (IJBB)     Open Access   (Followers: 3)
Indian Journal of Physics     Hybrid Journal   (Followers: 18)
Indian Journal of Pure & Applied Physics (IJPAP)     Open Access   (Followers: 36)
Indian Journal of Radio & Space Physics (IJRSP)     Open Access   (Followers: 49)
Infinite Dimensional Analysis, Quantum Probability and Related Topics     Hybrid Journal   (Followers: 1)
InfraMatics     Open Access  
Infrared Physics & Technology     Hybrid Journal   (Followers: 11)
Intelligent Transportation Systems Magazine, IEEE     Full-text available via subscription   (Followers: 12)
Intermetallics     Hybrid Journal   (Followers: 21)
International Applied Mechanics     Hybrid Journal   (Followers: 5)
International Heat Treatment and Surface Engineering     Hybrid Journal   (Followers: 5)
International Journal for Computational Methods in Engineering Science and Mechanics     Hybrid Journal   (Followers: 13)
International Journal for Ion Mobility Spectrometry     Hybrid Journal   (Followers: 1)
International Journal for Simulation and Multidisciplinary Design Optimization     Open Access   (Followers: 5)
International Journal of Abrasive Technology     Hybrid Journal   (Followers: 2)
International Journal of Aeroacoustics     Hybrid Journal   (Followers: 38)

        1 2 3 4 | Last

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Journal Cover
Axioms
Number of Followers: 1  

  This is an Open Access Journal Open Access journal
ISSN (Online) 2075-1680
Published by MDPI Homepage  [84 journals]
  • Axioms, Vol. 11, Pages 300: Smooth Versions of the
           Mann–Whitney–Wilcoxon Statistics

    • Authors: Netti Herawati, Ibrahim A. Ahmad
      First page: 300
      Abstract: The well-known Mann–Whitney–Wilcoxon (MWW) statistic is based on empirical distribution estimates. However, the data are often drawn from smooth populations. Therefore, the smoothness characteristic is not preserved. In addition, several authors have pointed out that empirical distribution is often an inadmissible estimate. Thus, in this work, we develop smooth versions of the MWW statistic based on smooth distribution function estimates. This approach preserves the data characteristics and allows the efficiency of the procedure to improve. In addition, our procedure is shown to be robust against a large class of dependent observations. Hence, by choosing a rectangular array of known distribution functions, our procedure allows the test to be a lot more reflective of the real data.
      Citation: Axioms
      PubDate: 2022-06-21
      DOI: 10.3390/axioms11070300
      Issue No: Vol. 11, No. 7 (2022)
       
  • Axioms, Vol. 11, Pages 301: New Theorems in Solving Families of Improper
           Integrals

    • Authors: Mohammad Abu Ghuwaleh, Rania Saadeh, Aliaa Burqan
      First page: 301
      Abstract: Many improper integrals appear in the classical table of integrals by I. S. Gradshteyn and I. M. Ryzhik. It is a challenge for some researchers to determine the method in which these integrations are formed or solved. In this article, we present some new theorems to solve different families of improper integrals. In addition, we establish new formulas of integrations that cannot be solved by mathematical software such as Mathematica or Maple. In this article, we present three main theorems that are essential in generating new formulas for solving improper integrals. To show the efficiency and the simplicity of the presented techniques, we present some applications and examples on integrations that cannot be solved by regular methods. Furthermore, we acquire new results for integrations and compare them to that obtained in the classical table of integrations. Some previous results, become special cases of our outcomes or generalizations to acquire new integrals.
      Citation: Axioms
      PubDate: 2022-06-21
      DOI: 10.3390/axioms11070301
      Issue No: Vol. 11, No. 7 (2022)
       
  • Axioms, Vol. 11, Pages 302: Information Measures Based on T-Spherical
           Fuzzy Sets and Their Applications in Decision Making and Pattern
           Recognition

    • Authors: Xiaomin Shen, Sidra Sakhi, Kifayat Ullah, Muhammad Nabeel Abid, Yun Jin
      First page: 302
      Abstract: The T-spherical fuzzy set (TSFS) is a modification of the fuzzy set (FS), intuitionistic fuzzy set (IFS), Pythagorean fuzzy set (PyFS), q-rung orthopair fuzzy set (q-ROFS), and picture fuzzy set (PFS), with three characteristic functions: the membership degree (MD) denoted by , the nonmembership degree (NMD) denoted by , and the abstinence degree (AD) denoted by . It can be used to solve problems of uncertain information with no restrictions. The distance measure (DM) is a tool that sums up the difference between points, while the similarity measure (SM) is a method applied to calculate the similarity between objects within an interval of . The current work aims to introduce novel DMs and SMs in the environment of TSFSs to show the limitations of the previously defined DMs and SMs. The suggested DMs and SMs provide more room for all three degrees to be selected without restriction. We investigated the effectiveness of the proposed DMs and SMs by applying a pattern-recognition technique, and we determined their applicability for multicriteria decision making (MCDM) using numerical examples. The newly proposed DMs and SMs are briefly compared to existing DMs and SMs, and appropriate conclusions are drawn.
      Citation: Axioms
      PubDate: 2022-06-21
      DOI: 10.3390/axioms11070302
      Issue No: Vol. 11, No. 7 (2022)
       
  • Axioms, Vol. 11, Pages 303: A Simultaneous Estimation of the Baseline
           Intensity and Parameters for Modulated Renewal Processes

    • Authors: Jiancang Zhuang, Hai-Yen Siew
      First page: 303
      Abstract: This paper proposes a semiparametric solution to estimate the intensity (hazard) function of modulated renewal processes: a nonparametric estimate for the baseline intensity function together with a parametric estimate of the model parameters of the covariate processes. Based on the martingale property associated with the conditional intensity, we construct a statistic from a residual analysis to estimate the baseline renewal intensity function, when the model parameters of the covariate processes are known. In addition, when the baseline intensity is obtained, the model parameters can be estimated using the usual maximum likelihood estimation. In practice, both the baseline intensity and model parameters are suggested to be estimated simultaneously via an expectation–maximization (E–M)-type iterative algorithm. A more important feature of the newly proposed algorithm is that, given n events in the observation dataset, its computation time is of order O(n2), while the Nelson–Aalen–Breslow estimator takes a computation time of order O(n3). For illustration, we apply the proposed estimation procedure to a set of data simulated from a modulated gamma renewal process and the aftershock sequence following the Ms8 Wenchuan earthquake, which occurred in Sichuan Province, China on 12 May 2008.
      Citation: Axioms
      PubDate: 2022-06-23
      DOI: 10.3390/axioms11070303
      Issue No: Vol. 11, No. 7 (2022)
       
  • Axioms, Vol. 11, Pages 304: Several Double Inequalities for Integer Powers
           of the Sinc and Sinhc Functions with Applications to the
           Neuman–Sándor Mean and the First Seiffert Mean

    • Authors: Wen-Hui Li, Qi-Xia Shen, Bai-Ni Guo
      First page: 304
      Abstract: In the paper, the authors establish a general inequality for the hyperbolic functions, extend the newly-established inequality to trigonometric functions, obtain some new inequalities involving the inverse sine and inverse hyperbolic sine functions, and apply these inequalities to the Neuman–Sándor mean and the first Seiffert mean.
      Citation: Axioms
      PubDate: 2022-06-23
      DOI: 10.3390/axioms11070304
      Issue No: Vol. 11, No. 7 (2022)
       
  • Axioms, Vol. 11, Pages 305: Software Defects Prediction Based on Hybrid
           Beetle Antennae Search Algorithm and Artificial Bee Colony Algorithm with
           Comparison

    • Authors: Ya Zhang, Tong Li, Zhen Li, Yu-Mei Wu, Hong Miao
      First page: 305
      Abstract: Software defects are problems in software that destroy normal operation ability and reflect the quality of the software. Software fault can be predicted by the software reliability model. In this paper, the hybrid algorithm is applied to parameter estimation in software defect prediction. As a biological heuristic algorithm, BAS (Beetle Antennae Search Algorithm) has fast convergence speed and is easy to implement. ABC (Artificial Bee Colony Algorithm) is better in optimization and has strong robustness. In this paper, the BAS-ABC hybrid algorithm is proposed by mixing the two algorithms and the goal of the proposed method is to improve the convergence and stability of the algorithm. Five datasets were used to carry out the experiments, and the data results showed that the hybrid algorithm was more accurate than the single algorithm, with stronger convergence and stability, so it was more suitable for parameter estimation of the software reliability model. Meanwhile, this paper implemented the comparison between hybrid BAS + ABC and hybrid PSO + SSA, and the result shows that BAS + ABC has better performance both in convergence and stability. The comparison result shows the strong ability in estimation and prediction of software defects hybrid BAS and ABC.
      Citation: Axioms
      PubDate: 2022-06-24
      DOI: 10.3390/axioms11070305
      Issue No: Vol. 11, No. 7 (2022)
       
  • Axioms, Vol. 11, Pages 306: A New Interior Search Algorithm for
           Energy-Saving Flexible Job Shop Scheduling with Overlapping Operations and
           Transportation Times

    • Authors: Lu Liu, Tianhua Jiang, Huiqi Zhu, Chunlin Shang
      First page: 306
      Abstract: Energy-saving scheduling has been pointed out as an interesting research issue in the manufacturing field, by which energy consumption can be effectively reduced through production scheduling from the operational management perspective. In recent years, energy-saving scheduling problems in flexible job shops (ESFJSPs) have attracted considerable attention from scholars. However, the majority of existing work on ESFJSPs assumed that the processing of any two consecutive operations in a job cannot be overlapped. In order to be close to real production, the processing overlapping of consecutive operations is allowed in this paper, while the job transportation tasks are also involved between different machines. To formulate the problem, a mathematical model is set up to minimize total energy consumption. Due to the NP-hard nature, a new interior search algorithm (NISA) is elaborately proposed following the feature of the problem. A number of experiments are conducted to verify the effectiveness of the NISA algorithm. The experimental results demonstrate that the NISA provides promising results for the considered problem. In addition, the computational results indicate that the increasing transportation time and sub-lot number will increase the transportation energy consumption, which is largely responsible for the increase in total energy consumption.
      Citation: Axioms
      PubDate: 2022-06-24
      DOI: 10.3390/axioms11070306
      Issue No: Vol. 11, No. 7 (2022)
       
  • Axioms, Vol. 11, Pages 307: Numerical Processes for Approximating
           Solutions of Nonlinear Equations

    • Authors: Samundra Regmi, Ioannis K. Argyros, Santhosh George, Christopher I. Argyros
      First page: 307
      Abstract: In this article, we present generalized conditions of three-step iterative schemes for solving nonlinear equations. The convergence order is shown using Taylor series, but the existence of high-order derivatives is assumed. However, only the first derivative appears on these schemes. Therefore, the hypotheses limit the utilization of the schemes to operators that are at least nine times differentiable, although the schemes may converge. To the best of our knowledge, no semi-local convergence has been given in the setting of a Banach space. Our goal is to extend the applicability of these schemes in both the local and semi-local convergence cases. Moreover, we use our idea of recurrent functions and conditions only on the derivative or divided differences of order one that appear in these schemes. This idea can be applied to extend other high convergence multipoint and multistep schemes. Numerical applications where the convergence criteria are tested complement this article.
      Citation: Axioms
      PubDate: 2022-06-24
      DOI: 10.3390/axioms11070307
      Issue No: Vol. 11, No. 7 (2022)
       
  • Axioms, Vol. 11, Pages 308: Stability of Fractional-Order Quasi-Linear
           Impulsive Integro-Differential Systems with Multiple Delays

    • Authors: Mathiyalagan Kalidass, Shengda Zeng, Mehmet Yavuz
      First page: 308
      Abstract: In this paper, some novel conditions for the stability results for a class of fractional-order quasi-linear impulsive integro-differential systems with multiple delays is discussed. First, the existence and uniqueness of mild solutions for the considered system is discussed using contraction mapping theorem. Then, novel conditions for Mittag–Leffler stability (MLS) of the considered system are established by using well known mathematical techniques, and further, the two corollaries are deduced, which still gives some new results. Finally, an example is given to illustrate the applications of the results.
      Citation: Axioms
      PubDate: 2022-06-25
      DOI: 10.3390/axioms11070308
      Issue No: Vol. 11, No. 7 (2022)
       
  • Axioms, Vol. 11, Pages 309: A Theoretical Dynamical Noninteracting Model
           for General Manipulation Systems Using Axiomatic Geometric Structures

    • Authors: Paolo Mercorelli
      First page: 309
      Abstract: This paper presents a new theoretical approach to the study of robotics manipulators dynamics. It is based on the well-known geometric approach to system dynamics, according to which some axiomatic definitions of geometric structures concerning invariant subspaces are used. In such a framework, certain typical problems in robotics are mathematically formalised and analysed in axiomatic form. The outcomes are sufficiently general that it is possible to discuss the structural properties of robotic manipulation. A generalized theoretical linear model is used, and a thorough analysis is made. The noninteracting nature of this model is also proven through a specific theorem.
      Citation: Axioms
      PubDate: 2022-06-25
      DOI: 10.3390/axioms11070309
      Issue No: Vol. 11, No. 7 (2022)
       
  • Axioms, Vol. 11, Pages 310: Covariant Space-Time Line Elements in the
           Friedmann–Lemaitre–Robertson–Walker Geometry

    • Authors: David Escors, Grazyna Kochan
      First page: 310
      Abstract: Most quantum gravity theories quantize space-time on the order of Planck length (ℓp ). Some of these theories, such as loop quantum gravity (LQG), predict that this discreetness could be manifested through Lorentz invariance violations (LIV) over travelling particles at astronomical length distances. However, reports on LIV are controversial, and space discreetness could still be compatible with Lorentz invariance. Here, it is tested whether space quantization on the order of Planck length could still be compatible with Lorentz invariance through the application of a covariant geometric uncertainty principle (GeUP) as a constraint over geodesics in FRW geometries. Space-time line elements compatible with the uncertainty principle are calculated for a homogeneous, isotropic expanding Universe represented by the Friedmann–Lemaitre–Robertson–Walker solution to General Relativity (FLRW or FRW metric). A generic expression for the quadratic proper space-time line element is derived, proportional to Planck length-squared, and dependent on two contributions. The first is associated to the energy–time uncertainty, and the second depends on the Hubble function. The results are in agreement with space-time quantization on the expected length orders, according to quantum gravity theories, and within experimental constraints on putative LIV.
      Citation: Axioms
      PubDate: 2022-06-26
      DOI: 10.3390/axioms11070310
      Issue No: Vol. 11, No. 7 (2022)
       
  • Axioms, Vol. 11, Pages 311: A Very Simple Procedure for Constructing the
           Solution of Nonlinear Elliptic PDEs (with Nonlinear Boundary Conditions)
           Arising from Heat Transfer Problems in Solids

    • Authors: Rogério Martins Saldanha da Saldanha da Gama
      First page: 311
      Abstract: This work presents a procedure for constructing the solution of a second order nonlinear partial differential equation subjected to nonlinear boundary conditions in a very simple and systematic way. The class of equations to be considered here includes, but is not limited to, the partial differential equations which govern the steady-state heat transfer process in bodies with temperature-dependent thermal conductivity and temperature-dependent internal heat source. In addition, it will be considered a large class of nonlinear boundary conditions, especially those arising from the description of the heat exchange process from/to bodies at high temperature levels. Proofs of the solution’s existence and uniqueness are presented.
      Citation: Axioms
      PubDate: 2022-06-26
      DOI: 10.3390/axioms11070311
      Issue No: Vol. 11, No. 7 (2022)
       
  • Axioms, Vol. 11, Pages 312: Formation and Evolution of Ideal Interfirm
           Collaborative Innovation Networks Based on Decision-Making Rules for
           Partner Selection

    • Authors: Houxing Tang, Jiaqi Meng, Qifan Hu, Fang Li, Yanping Gui
      First page: 312
      Abstract: On the basis of an external and static perspective on the topological structure of collaborative innovation networks, it is extremely difficult to answer the two most important concerns, namely, which structure is ideal and how to develop it in practice. By contrast, this study transfers to internal and dynamic perspectives, and then proposes that the essence of developing the ideal network lies in choosing the best partners. Therefore, we firstly propose the basic decision-making rules for selecting partners. In order of priority: knowledge distance, knowledge complementarity and barter exchange. Secondly, a model is constructed to describe this process of selecting partners and exchanging knowledge. Thirdly, the simulation results show that a small-world network is ideal in the initial stage of collaborative innovation. However, a random network is ideal in the mature periods. This result shows that the ideal network structure is not fixed, but affected by the life cycle of collaborative innovation alliance. Furthermore, this supports the notion that a small world is spontaneously generated in the real world, and also confirms that the formation of a small-world network will be driven intrinsically by a firm’s demand for external knowledge, and not necessarily by the external driving force of social capital. Finally, these findings solve the above two most important questions.
      Citation: Axioms
      PubDate: 2022-06-26
      DOI: 10.3390/axioms11070312
      Issue No: Vol. 11, No. 7 (2022)
       
  • Axioms, Vol. 11, Pages 313: Pattern Formation Induced by Fuzzy
           Fractional-Order Model of COVID-19

    • Authors: Abeer S. Alnahdi, Ramsha Shafqat, Azmat Ullah Khan Niazi, Mdi Begum Jeelani
      First page: 313
      Abstract: A novel coronavirus infection system is established for the analytical and computational aspects of this study, using a fuzzy fractional evolution equation (FFEE) stated in Caputo’s sense for order (1,2). It is constructed using the FFEE formulated in Caputo’s meaning. The model consist of six components illustrating the coronavirus outbreak, involving the susceptible people Kℓ(ω), the exposed population Lℓ(ω), total infected strength Cℓ(ω), asymptotically infected population Mℓ(ω), total number of humans recovered Eℓ(ω), and reservoir Qℓ(ω). Numerical results using the fuzzy Laplace approach in combination with the Adomian decomposition transform are developed to better understand the dynamical structures of the physical behavior of COVID-19. For the controlling model, such behavior on the generic characteristics of RNA in COVID-19 is also examined. The findings show that the proposed technique of addressing the uncertainty issue in a pandemic situation is effective.
      Citation: Axioms
      PubDate: 2022-06-27
      DOI: 10.3390/axioms11070313
      Issue No: Vol. 11, No. 7 (2022)
       
  • Axioms, Vol. 11, Pages 314: TT-M Finite Element Algorithm for the Coupled
           Schrödinger–Boussinesq Equations

    • Authors: Jiale Tian, Ziyu Sun, Yang Liu, Hong Li
      First page: 314
      Abstract: In this article, the coupled Schrödinger–Boussinesq equations are solved numerically using the finite element method combined with the time two-mesh (TT-M) fast algorithm. The spatial direction is discretized by the standard Galerkin finite element method, the temporal direction is approximated by the TT-M Crank–Nicolson scheme, and then the numerical scheme of TT-M finite element (FE) system is formulated. The method includes three main steps: for the first step, the nonlinear system is solved on the coarse time mesh; for the second step, by an interpolation formula, the numerical solutions at the fine time mesh point are computed based on the numerical solutions on the coarse mesh system; for the last step, the linearized temporal fine mesh system is constructed based on Taylor’s formula for two variables, and then the TT-M FE solutions can be obtained. Furthermore, theory analyses on the TT-M system including the stability and error estimations are conducted. Finally, a large number of numerical examples are provided to verify the accuracy of the algorithm, the correctness of theoretical results, and the computational efficiency with a comparison to the numerical results calculated by using the standard FE method.
      Citation: Axioms
      PubDate: 2022-06-28
      DOI: 10.3390/axioms11070314
      Issue No: Vol. 11, No. 7 (2022)
       
  • Axioms, Vol. 11, Pages 315: Measuring Profitable Efficiency, Technical
           Efficiency, Technological Innovation of Waste Management Companies Using
           Negative Super-SBM–Malmquist Model

    • Authors: Chia-Nan Wang, Quynh-Ngoc Hoang, Thi-Kim-Lien Nguyen, Hsien-Pin Hsu, Thanh-Tuan Dang
      First page: 315
      Abstract: In recent decades, waste generation has increased gradually because of the development of the quantity and size of businesses, together with the high growth rate of the population. However, in 2019, like other industries, the waste management industry was affected by the COVID-19 pandemic, particularly in relation to aspects concentrated on strategy. Subsequently, appropriate waste management in all aspects of the community, specifically for waste management enterprises, was demanded. This research aims to assess the profitable efficiency, position, technical, and technological innovation and compare the global major waste management corporations by integrating the negative super-slacks-based measure model and the negative Malmquist model in data envelopment analysis. Various inputs and outputs are initially selected from nine waste management companies’ financial statements from 2017 to 2020, including negative values, to attain their performance. The empirical results indicated that waste management companies’ managers could make better investment or strategy decisions for superior performance. At the same time, collaborators from other sectors could find their potential partners in the waste management industry. In general, considering the efficiency, Veolia Environment (DMU3) and Heritage-Crystal Clean Company (DMU8) were the most efficient companies. Meanwhile, Covanta Holding (DMU2) and Republic Services Corporation (DMU5) required additional development to improve their performance. Besides, because of the disparity in technical and technological innovation, most decision-making units could not achieve consistent improvement in terms of technical, technological change, and total production.
      Citation: Axioms
      PubDate: 2022-06-28
      DOI: 10.3390/axioms11070315
      Issue No: Vol. 11, No. 7 (2022)
       
  • Axioms, Vol. 11, Pages 316: Refinements to Relation-Theoretic Contraction
           Principle

    • Authors: Aftab Alam, Reny George, Mohammad Imdad
      First page: 316
      Abstract: After the appearance of relation-theoretic contraction principle proved in a metric space equipped with an amorphous binary relation (often termed as relational metric space), various core fixed point results have been proved in the setting of different relational distance spaces by varying underlying contraction conditions. In proving such results, the notions of completeness of ambient space, continuity of involved mapping and d-self-closedness of underlying binary relation are of paramount importance. The aim of this paper is to further refine the relation-theoretic contraction principle by relaxing the conditions of completeness and continuity by replacing their respective relation-theoretic analogues. Moreover, we observe that the notion of d-self-closedness utilized in relation-theoretic contraction principle is more general than the concepts of regularity and strong regularity utilized by earlier authors.
      Citation: Axioms
      PubDate: 2022-06-28
      DOI: 10.3390/axioms11070316
      Issue No: Vol. 11, No. 7 (2022)
       
  • Axioms, Vol. 11, Pages 317: CT-Integral on Interval-Valued Sugeno
           Probability Measure and Its Application in Multi-Criteria Decision-Making
           Problems

    • Authors: Hong Yang, Liyan Shang, Zengtai Gong
      First page: 317
      Abstract: It is well known that the complexity of the decision-making environment frequently coexists with the diversity of linguistic information in the decision-making process. In order to solve this kind of uncertain multi-criteria decision-making problem, reasonable measures and integrals should be established. In this paper, the discrete expression of the CT-integral on the interval-valued Sugeno probability measure is proposed. The CT-integral is the Choquet integral when the t-norm is T(x,y)=xy in the CT-integral and is a pre-aggregation function. Then, the CT-integral on interval-valued Sugeno probability measure is applied to solve end-of-life (EOL) strategy in order to determine multi-criteria decision-making problems. Compared with the general Choquet integral, the method proposed in this paper significantly improves the calculation process, that is, the calculation is simpler and the amount of calculation is smaller. A case study was performed in order to validate the effectiveness of this conclusion.
      Citation: Axioms
      PubDate: 2022-06-29
      DOI: 10.3390/axioms11070317
      Issue No: Vol. 11, No. 7 (2022)
       
  • Axioms, Vol. 11, Pages 318: A Simple Greedy Heuristic for Site Specific
           Management Zone Problem

    • Authors: Luis Eduardo Urbán Rivero, Jonás Velasco, Javier Ramírez Rodríguez
      First page: 318
      Abstract: In agriculture, the soil properties influence the productivity and quality of crops. The farmer expects that in a specific area of the land, the physicochemical characteristics of the soil will be homogeneous as the selected crop has the desired quality and minimizes the use of fertilizers. There are three approaches to determining the correct delimitation of the land in the state-of-the art. The first one (k-means and fuzzy k-means) is impractical for current agricultural technology. The second approach is based on integer linear programming and a pre-processing step. This approach limits the shapes of delimited zones to rectangular, and the third approach extends the solution search space and generates orthogonal regions using Estimation of Distribution Algorithms (EDA). In this work, we generate orthogonal regions with a different approach to the EDA, a greedy construction heuristic. Our heuristic produces feasible solutions with a reasonable running time compared with the running times of EDA.
      Citation: Axioms
      PubDate: 2022-06-29
      DOI: 10.3390/axioms11070318
      Issue No: Vol. 11, No. 7 (2022)
       
  • Axioms, Vol. 11, Pages 319: On Newton’s First Law of Motion

    • Authors: Goran Peskir
      First page: 319
      Abstract: We present arguments in support of the view that Newton’s first law of motion extends itself to stochastic motions as follows: Every entity perseveres in its state of independent and stationary increments except insofar as it is compelled to change its state by forces impressed. Some of the far-reaching consequences of the extended law are briefly touched upon as well.
      Citation: Axioms
      PubDate: 2022-06-29
      DOI: 10.3390/axioms11070319
      Issue No: Vol. 11, No. 7 (2022)
       
  • Axioms, Vol. 11, Pages 244: A Spatially Bounded Airspace Axiom

    • Authors: Peter Szabó, Miroslava Ferencová, Monika Blišťanová
      First page: 244
      Abstract: Free Route Airspace (FRA), a new concept implemented across European airspace, is designed to eliminate the adverse effects of air traffic, reduce fuel consumption, simplify and expand flight planning. In our research, we model FRA system by using graph theory and we use networks and convex analysis to study it. We work with 2-dimensional space defined by latitude a longitude. We know that the basic mathematical properties of a scientific discipline can be expressed using mathematical axioms. Therefore, in our work, we sought to answer the question, what are the basic mathematical properties of airspace' We found a mathematical object that can describe airspace in general. Using this object, we uttered an axiom describing airspace. Our axiom is given by means of practical, significant entry and entry-exit points in the airspace.
      Citation: Axioms
      PubDate: 2022-05-24
      DOI: 10.3390/axioms11060244
      Issue No: Vol. 11, No. 6 (2022)
       
  • Axioms, Vol. 11, Pages 245: Macdonald Formula, Ricci Curvature, and
           Concentration Locus for Classical Compact Lie Groups

    • Authors: Sergio Cacciatori, Pietro Ursino
      First page: 245
      Abstract: We consider the phenomenon of concentration of measures, which is restricted to the case of families of compact connected Lie groups. While in the literature, powerful general results regarding the existence of concentration and its relations to extremal amenability of infinite dimensional groups have been determined, there are few explicit examples, specially regarding the determination of the region where the measure concentrates. Since they can be relevant for concrete applications, both in mathematics and in physics, in the present paper, we provide a number of such examples, using compact Lie groups as basic ingredients. In particular, our strategy is to employ the Macdonald’s formula, giving the volume of compact simple Lie groups, and Ricci curvature of the bi-invariant metric for analyzing a “concentration locus”, which is a tool to detect where a sequence of metric, Borel measurable spaces concentrates its measure.
      Citation: Axioms
      PubDate: 2022-05-24
      DOI: 10.3390/axioms11060245
      Issue No: Vol. 11, No. 6 (2022)
       
  • Axioms, Vol. 11, Pages 246: Adaptive Enhancement for Coal-Rock Cutting
           Sound Based on Parameter Self-Tuning Bistable Stochastic Resonance Model

    • Authors: Jie Xu, Jing Xu, Chaofan Ren, Yanxin Liu, Ning Sun
      First page: 246
      Abstract: The traditional bistable stochastic resonance model has always had the drawback of being difficult when choosing accurate system parameters when a weak signal is enhanced. This paper proposes a parameter self-tuning adaptive optimization method based on the bat optimization algorithm to address this issue. The cubic mapping strategy of chaos optimization is introduced in the initial process of the individual position of the bat algorithm. Chaos is characterized by randomness, sensitivity, fractal dimension, and universality. The initial problem of the algorithm falling into local extremums is overcome. The global search capability of the basic bat optimization algorithm has been improved. The improved bat optimization algorithm’s objective function is the signal-to-noise ratio (SNR) of the target weak signal output by the bistable stochastic resonance model. An adaptive signal enhancement algorithm based on the improved bat optimization algorithm and bistable stochastic resonance (IBA-BSR) model is constructed to increase the proportion of weak signals in the mixed signal. Simulation signals are created to validate the proposed algorithm’s feasibility. The engineering application effect of this algorithm is further demonstrated by enhancing the sound signal of coal and rock cutting by a shearer in a coal face. Engineering test results demonstrate that this algorithm can significantly increase the SNR of coal and rock cutting sound signals by 42.4537 dB, and the effect is remarkable.
      Citation: Axioms
      PubDate: 2022-05-25
      DOI: 10.3390/axioms11060246
      Issue No: Vol. 11, No. 6 (2022)
       
  • Axioms, Vol. 11, Pages 247: Exact Solutions of Nonlinear Partial
           Differential Equations via the New Double Integral Transform Combined with
           Iterative Method

    • Authors: Shams A. Ahmed, Ahmad Qazza, Rania Saadeh
      First page: 247
      Abstract: This article demonstrates how the new Double Laplace–Sumudu transform (DLST) is successfully implemented in combination with the iterative method to obtain the exact solutions of nonlinear partial differential equations (NLPDEs) by considering specified conditions. The solutions of nonlinear terms of these equations were determined by using the successive iterative procedure. The proposed technique has the advantage of generating exact solutions, and it is easy to apply analytically on the given problems. In addition, the theorems handling the mode properties of the DLST have been proved. To prove the usability and effectiveness of this method, examples have been given. The results show that the presented method holds promise for solving other types of NLPDEs.
      Citation: Axioms
      PubDate: 2022-05-25
      DOI: 10.3390/axioms11060247
      Issue No: Vol. 11, No. 6 (2022)
       
  • Axioms, Vol. 11, Pages 248: Edge Neighbor Toughness of Graphs

    • Authors: Xin Feng, Zongtian Wei, Yucheng Yang
      First page: 248
      Abstract: A new graph parameter, edge neighbor toughness is introduced to measure how difficult it is for a graph to be broken into many components through the deletion of the closed neighborhoods of a few edges. Let G=(V,E) be a graph. An edge e is said to be subverted when its neighborhood and the two endvertices are deleted from G. An edge set S⊆E(G) is called an edge cut-strategy if all the edges in S has been subverted from G and the survival subgraph, denoted by G/S, is disconnected, or is a single vertex, or is. The edge neighbor toughness of a graph G is defined to be tEN(G)=minS⊆E(G){ S c(G/S)}, where S is any edge cut strategy of G, c(G/S) is the number of the components of G/S. In this paper, the properties of this parameter are investigated, and the proof of the computation problem of edge neighbor toughness is NP-complete; finally, a polynomial algorithm for computing the edge neighbor toughness of trees is given.
      Citation: Axioms
      PubDate: 2022-05-25
      DOI: 10.3390/axioms11060248
      Issue No: Vol. 11, No. 6 (2022)
       
  • Axioms, Vol. 11, Pages 249: An Earthquake-Clustering Model in North Aegean
           Area (Greece)

    • Authors: Ourania Mangira, Rodolfo Console, Eleftheria Papadimitriou, Maura Murru, Vasileios Karakostas
      First page: 249
      Abstract: The investigation of short-term earthquake-clustering features is made feasible through the application of a purely stochastic Epidemic-Type Aftershock Sequence (ETAS) model. The learning period that is used for the estimation of the parameters is composed by earthquakes with M ≥ 2.6 that occurred between January 2008 and May 2017. The model predictability is retrospectively examined for the 12 June 2017 Lesvos earthquake (Mw6.4) and the subsequent events. The construction of time-dependent seismicity maps and comparison between the observed and expected earthquake number are performed in order to temporally and spatially test the evolution of the sequence, respectively. The generation of 127 target events with M ≥ 3.0 in the period June–July 2017, just before the main shock occurrence, is examined in a quantitative evaluation. The statistical criteria used for assessing the model performance are the Relative Operating Characteristic Diagram, the R-score, and the probability gain. Reliable forecasts are provided through the epidemic model testifying its superiority towards a time-invariant Poisson model.
      Citation: Axioms
      PubDate: 2022-05-26
      DOI: 10.3390/axioms11060249
      Issue No: Vol. 11, No. 6 (2022)
       
  • Axioms, Vol. 11, Pages 250: Further Study on C-Eigenvalue Inclusion
           Intervals for Piezoelectric Tensors

    • Authors: Gang Wang, Xiaoxuan Yang, Wei Shao, Qiuling Hou
      First page: 250
      Abstract: The C-eigenpair of piezoelectric tensors finds applications in the area of the piezoelectric effect and converse piezoelectric effect. In this paper, we provide some characterizations of C-eigenvectors by exploring the structure of piezoelectric tensors, and establish sharp C-eigenvalue inclusion intervals via Cauchy–Schwartz inequality. Further, we propose the lower and upper bounds of the largest C-eigenvalue and evaluate the efficiency of the best rank-one approximation of piezoelectric tensors. Numerical examples are proposed to verify the efficiency of the obtained results.
      Citation: Axioms
      PubDate: 2022-05-26
      DOI: 10.3390/axioms11060250
      Issue No: Vol. 11, No. 6 (2022)
       
  • Axioms, Vol. 11, Pages 251: Interval Type-3 Fuzzy Aggregation of Neural
           Networks for Multiple Time Series Prediction: The Case of Financial
           Forecasting

    • Authors: Oscar Castillo, Juan R. Castro, Patricia Melin
      First page: 251
      Abstract: In this work, we present an approach for fuzzy aggregation of neural networks for forecasting. The interval type-3 aggregator is used to combine the outputs of the networks to improve the quality of the prediction. This is carried out in such a way that the final output is better than the outputs of the individual modules. In our approach, a fuzzy system is used to estimate the prediction increments that will be assigned to the output in the process of combining them with a set of fuzzy rules. The uncertainty in the process of aggregation is modeled with an interval type-3 fuzzy system, which, in theory, can outperform type-2 and type-1 fuzzy systems. Publicly available data sets of COVID-19 cases and the Dow Jones index were utilized to test the proposed approach, as it has been stated that a pandemic wave can have an effect on the economies of countries. The simulation results show that the COVID-19 data does have, in fact, an influence on the Dow Jones time series and its use in the proposed model improves the forecast of the Dow Jones future values.
      Citation: Axioms
      PubDate: 2022-05-26
      DOI: 10.3390/axioms11060251
      Issue No: Vol. 11, No. 6 (2022)
       
  • Axioms, Vol. 11, Pages 252: General Opial Type Inequality and New Green
           Functions

    • Authors: Ana Gudelj, Kristina Krulić Himmelreich, Josip Pečarić
      First page: 252
      Abstract: In this paper we provide many new results involving Opial type inequalities. We consider two functions—one is convex and the other is concave—and prove a new general inequality on a measure space (Ω,Σ,μ). We give an new result involving four new Green functions. Our results include Grüss and Ostrowski type inequalities related to the generalized Opial type inequality. The obtained inequalities are of Opial type because the integrals contain the function and its integral representation. They are not a direct generalization of the Opial inequality.
      Citation: Axioms
      PubDate: 2022-05-26
      DOI: 10.3390/axioms11060252
      Issue No: Vol. 11, No. 6 (2022)
       
  • Axioms, Vol. 11, Pages 253: Development of Patent Technology Prediction
           Model Based on Machine Learning

    • Authors: Chih-Wei Lee, Feng Tao, Yu-Yu Ma, Hung-Lung Lin
      First page: 253
      Abstract: Intellectual property rights have a great impact on the development of the automobile industry. Issues related to the timeliness of patent applications often arise, such as the inability of firms to predict new technologies and patents developed by peers. To find the proper direction of product development, the R&D departments of enterprises need to accurately predict the technology trends. Machine learning adopts calculation through a large amount of data through mathematical models and methods and finds the best solution at the fastest speed through repeated simulation and experiments, to provide decision makers with a reference basis. Therefore, this paper provides accurate forecasts through established models. In terms of the significance of management, the planning of future enterprise strategy can be divided into three stages as a short-term plan of 1–3 years, a medium-term plan of 3–5 years, and a long-term plan of 5–10 years. This study will give appropriate suggestions for the development of automobile industry technology.
      Citation: Axioms
      PubDate: 2022-05-26
      DOI: 10.3390/axioms11060253
      Issue No: Vol. 11, No. 6 (2022)
       
  • Axioms, Vol. 11, Pages 254: Total Rainbow Connection Number of Some Graph
           Operations

    • Authors: Hengzhe Li, Yingbin Ma, Yan Zhao
      First page: 254
      Abstract: In a graph H with a total coloring, a path Q is a total rainbow if all elements in V(Q)∪E(Q), except for its end vertices, are assigned different colors. The total coloring of a graph H is a total rainbow connected coloring if, for any x,y∈V(H), there is a total rainbow path joining them. The total rainbow connection number trc(H) of H is the minimum integer r such that there is a total rainbow-connected coloring of H using r colors. In this paper, we study the total rainbow connection number of several graph operations (specifically, adding an edge, deleting an edge, and the Cartesian product) for which the total rainbow connection number is upper-bounded by a linear function of its radius.
      Citation: Axioms
      PubDate: 2022-05-26
      DOI: 10.3390/axioms11060254
      Issue No: Vol. 11, No. 6 (2022)
       
  • Axioms, Vol. 11, Pages 255: On the Generalized Gaussian Fibonacci Numbers
           and Horadam Hybrid Numbers: A Unified Approach

    • Authors: Fatih Yılmaz, Mustafa Özkan
      First page: 255
      Abstract: In this paper, we consider an approach based on the elementary matrix theory. In other words, we take into account the generalized Gaussian Fibonacci numbers. In this context, we consider a general tridiagonal matrix family. Then, we obtain determinants of the matrix family via the Chebyshev polynomials. Moreover, we consider one type of tridiagonal matrix, whose determinants are Horadam hybrid polynomials, i.e., the most general form of hybrid numbers. Then, we obtain its determinants by means of the Chebyshev polynomials of the second kind. We provided several illustrative examples, as well.
      Citation: Axioms
      PubDate: 2022-05-26
      DOI: 10.3390/axioms11060255
      Issue No: Vol. 11, No. 6 (2022)
       
  • Axioms, Vol. 11, Pages 256: Dynamical Analysis of a Modified Epidemic
           Model with Saturated Incidence Rate and Incomplete Treatment

    • Authors: Lazarus Kalvein Beay, Nursanti Anggriani
      First page: 256
      Abstract: This paper addresses a modified epidemic model with saturated incidence and incomplete treatment. The existence of all equilibrium points is analyzed. A reproduction number R0 is determined. Next, it is found that the non-endemic point P0 is stable in case R0<1, but unstable in case R0>1. The special conditions to analyze the local and global stability of the non-endemic and endemic points are investigated. Globally, the sensitivity analysis of the system is studied by combining the Latin Hypercube Sampling and Partial Rating Correlation Coefficients methods. By using the Pontryagins maximum principle, the optimal control problem is studied. Various numerical results are given to support our analysis.
      Citation: Axioms
      PubDate: 2022-05-27
      DOI: 10.3390/axioms11060256
      Issue No: Vol. 11, No. 6 (2022)
       
  • Axioms, Vol. 11, Pages 257: Recursive Aggregation and Its Fusion Process
           for Intuitionistic Fuzzy Numbers Based on Non-Additive Measure

    • Authors: Yongfu Shi, Zengtai Gong
      First page: 257
      Abstract: In this paper, the recursive aggregation of OWA operators for intuitionistic fuzzy numbers (IFN) based on a non-additive measure (NAM) with σ−λ rules is constructed and investigated in light of the σ−λ rules of a non-additive measure (NAM). Additionally, an integrator is designed by drawing on the genetic algorithm and the process of calculation is elaborated by an example.
      Citation: Axioms
      PubDate: 2022-05-28
      DOI: 10.3390/axioms11060257
      Issue No: Vol. 11, No. 6 (2022)
       
  • Axioms, Vol. 11, Pages 258: Analysis of Interval-Valued Intuitionistic
           Fuzzy Aczel–Alsina Geometric Aggregation Operators and Their
           Application to Multiple Attribute Decision-Making

    • Authors: Tapan Senapati, Radko Mesiar, Vladimir Simic, Aiyared Iampan, Ronnason Chinram, Rifaqat Ali
      First page: 258
      Abstract: When dealing with the haziness that is intrinsic in decision analysis-driven decision making procedures, interval-valued intuitionistic fuzzy sets (IVIFSs) can be quite effective. Our approach to solving the multiple attribute decision making (MADM) difficulties, where all of the evidence provided by the decision-makers is demonstrated as interval-valued intuitionistic fuzzy (IVIF) decision matrices, in which all of the components are distinguished by an IVIF number (IVIFN), is based on Aczel–Alsina operational processes. We begin by introducing novel IVIFN operations including the Aczel–Alsina sum, product, scalar multiplication, and exponential. We may then create IVIF aggregation operators, such as the IVIF Aczel–Alsina weighted geometric operator, the IVIF Aczel–Alsina ordered weighted geometric operator, and the IVIF Aczel–Alsina hybrid geometric operator, among others. We present a MADM approach that relies on the IVIF aggregation operators that have been developed. A case study is used to demonstrate the practical applicability of the strategies proposed in this paper. By contrasting the newly developed technique with existing techniques, the method is capable of demonstrating the advantages of the newly developed approach. A key result of this work is the discovery that some of the current IVIF aggregation operators are subsets of the operators reported in this article.
      Citation: Axioms
      PubDate: 2022-05-29
      DOI: 10.3390/axioms11060258
      Issue No: Vol. 11, No. 6 (2022)
       
  • Axioms, Vol. 11, Pages 259: Volatility Co-Movement between Bitcoin and
           

    • Authors: Kuo-Shing Chen, Shen-Ho Chang
      First page: 259
      Abstract: This paper aims to investigate and measure Bitcoin and the five largest stablecoin market volatilities by incorporating various range-based volatility estimators to the BEKK- GARCH and Copula-DCC-GARCH models. Specifically, we further measure Bitcoins’ volatility related to five major stablecoins and examine the connectedness between Bitcoin and the stablecoins. Our empirical findings document that the connectedness between Bitcoin and stablecoin market volatility behaviors exhibits the presence of stable interconnection. This study is of particular importance since it is crucial for market participation in the ongoing crypto assets to be informed about both the volatility patterns of major cryptocurrencies and the relative volatility of Bitcoin against the stablecoin markets. Eventually, we find that there is no systematic evidence for the various parity deviations of the stablecoins that are profoundly impacted by Bitcoin volatility. Thus, Bitcoin and the largest stablecoin Tether could stabilize together. However, Bitcoin shall not be generalized to other stablecoins in terms of stability results.
      Citation: Axioms
      PubDate: 2022-05-29
      DOI: 10.3390/axioms11060259
      Issue No: Vol. 11, No. 6 (2022)
       
  • Axioms, Vol. 11, Pages 260: Spectral Invariants and Their Application on
           Spectral Characterization of Graphs

    • Authors: Jun Yin, Haixing Zhao, Sun Xie
      First page: 260
      Abstract: In this paper, we give a method to characterize graphs determined by their adjacency spectrum. At first, we give two parameters Π1(G) and Π2(G), which are related to coefficients of the characteristic polynomial of graph G. All connected graphs with Π1(G) ∈ {1,0,−1,−2,−3} and Π2(G) ∈ {0,−1,−2,−3} are characterized. Some interesting properties of Π1(G) and Π2(G) are also given. We then find the necessary and sufficient conditions for two classes of graphs to be determined by their adjacency spectrum.
      Citation: Axioms
      PubDate: 2022-05-29
      DOI: 10.3390/axioms11060260
      Issue No: Vol. 11, No. 6 (2022)
       
  • Axioms, Vol. 11, Pages 261: The Expected Value of Hosoya Index and
           Merrifield–Simmons Index in a Random Cyclooctylene Chain

    • Authors: Yushuang Sun, Xianya Geng
      First page: 261
      Abstract: The Hosoya index m(G) and the Merrifield–Simmons index i(G) of a graph G are the number of matchings and the number of independent sets in G. In this paper, we establish exact formulas for the expected value of the Hosoya index and Merrifield–Simmons index of the random cyclooctylene chains, which are graphs of a chemical chain consisting of n octagons, each of which is connected to the end of the previous octagon by an edge. In addition, we obtain the expected values and the average values of the two indexes through the relevant chemical diagrams and a series of accurate formulas with respect to the set of all cyclooctylene chains with n octagons.
      Citation: Axioms
      PubDate: 2022-05-30
      DOI: 10.3390/axioms11060261
      Issue No: Vol. 11, No. 6 (2022)
       
  • Axioms, Vol. 11, Pages 262: Bounds for Quotients of Inverse Trigonometric
           and Inverse Hyperbolic Functions

    • Authors: Sumedh B. Thool, Yogesh J. Bagul, Ramkrishna M. Dhaigude, Christophe Chesneau
      First page: 262
      Abstract: We establish new simple bounds for the quotients of inverse trigonometric and inverse hyperbolic functions such as sin−1xsinh−1x and tanh−1xtan−1x. The main results provide polynomial bounds using even quadratic functions and exponential bounds under the form eax2. Graph validation is also performed.
      Citation: Axioms
      PubDate: 2022-05-30
      DOI: 10.3390/axioms11060262
      Issue No: Vol. 11, No. 6 (2022)
       
  • Axioms, Vol. 11, Pages 263: A GIS-MCDM Method for Ranking Potential
           Station Locations in the Expansion of Bike-Sharing Systems

    • Authors: Mohammad Sadegh Bahadori, Alexandre B. Gonçalves, Filipe Moura
      First page: 263
      Abstract: Bicycle-sharing systems (BSSs) are an effective solution to reduce private car usage in most cities and are an influential factor in encouraging citizens to shift to more sustainable transport modes. In this sense, the location of BSS stations has a critical impact on the system’s efficiency. This study proposed an integrated geographic information system–multi-criteria decision-making (GIS-MCDM) framework that includes the analytic hierarchy process (AHP), technique for order preference by similarity to the ideal solution (TOPSIS), and spatial data processing in GIS to determine a ranking of potential locations for BSS stations. The results of the proposed GIS-MCDM method can be used for both planning a new BSS or expanding one that is currently under operation. The framework was applied to a case study for expanding GIRA, the BSS of Lisbon, Portugal. In it, location criteria were selected in four categories, including criteria from the literature and extracted from available transaction data; in addition, we also suggested some criteria. The rebalancing operator’s staff were the decision makers in this study via their responses to the AHP questionnaire. The rebalancing staff believed that the main criterion of “city infrastructure” with the two sub-criteria of “population density” and “slope” were the most important. Furthermore, the proximity to the “bike network” with the sub-criterion of “proximity to the current bike stations” had less importance. Each criterion’s weight and inconsistency rate were obtained using the Expert Choice software. The geographic values of each criterion were created utilizing the ArcGIS software, and its network analyst module was employed for applying location techniques. Based on the created suitability map, the city’s center was the main suitable area for establishing new stations. Forty-five new bike stations were identified in those areas and ranked using the TOPSIS technique.
      Citation: Axioms
      PubDate: 2022-05-31
      DOI: 10.3390/axioms11060263
      Issue No: Vol. 11, No. 6 (2022)
       
  • Axioms, Vol. 11, Pages 264: Mathematical Modeling Research Output
           Impacting New Technological Development: An Axiomatization to Build
           Novelty

    • Authors: Mohd Razip Bajuri, Zailan Siri, Mohd Nor Syahrir Abdullah
      First page: 264
      Abstract: The mathematical modeling of research-based output impacting new technology development is crucial for a developing country. However, the complexity of modern mathematical modeling research output makes it unclear over how it can impact the development of new technology. Therefore, this study aims to explore, categorize and formulize the axioms of mathematical modeling research output that impacts the development of new technology. Seven participants were involved in this research. Interviews were conducted to explore their remarkable mathematical modeling output and how the output can impact the development of new technology. The categorization axioms are: i. mathematical modeling for theorizing, ii. mathematical modeling for simulations, iii. mathematical modeling for useable innovation and iv. patent and product commercialization. Finally, the categorization can be formulized as an axiom of mathematical modeling novelty, which is the desired research output. Moreover, patents and commercialization are the elements that mathematical modeling should possess for new technological development. The limited number of participants involved in this study makes this study formulation limited to only some types of mathematical modeling output. However, this substantive formulation could give some ideas in proposing the path and processes on how to enhance the effort for society to develop the culture of mathematical modeling in developing new technology.
      Citation: Axioms
      PubDate: 2022-05-31
      DOI: 10.3390/axioms11060264
      Issue No: Vol. 11, No. 6 (2022)
       
  • Axioms, Vol. 11, Pages 265: A Recommendation Model for Selling Rules in
           the Telecom Retail Industry

    • Authors: Tsung-Ying Ou, Wen-Lung Tsai, Yi-Chen Lee, Tien-Hsiang Chang, Shih-Hsiung Lee, Fen-Fen Huang
      First page: 265
      Abstract: The recommendation of the optimal selling rules for any product or service is challenging, owing to the complexity of the customer’s behavior and the competitiveness existing in the telecom retail industry. This study proposes a recommendation model for selling rules that utilizes a hybrid decision-making approach based on K-means and the C5.0 decision tree to analyze the historical sales information of telecom retailers. To evaluate the efficacy of the proposed recommendation model, it was used to analyze original data from a case company. The results indicated that the proposed hybrid decision-making approach resulted in sales content with a high gross profit and high agreement rates. The experimental results show each cluster that can be used to identify rules for the combination of good tariff items in different tariff ranges. Rules for the recommendation of special tariffs are also established to assist salespeople.
      Citation: Axioms
      PubDate: 2022-06-01
      DOI: 10.3390/axioms11060265
      Issue No: Vol. 11, No. 6 (2022)
       
  • Axioms, Vol. 11, Pages 266: On Fractional Inequalities Using Generalized
           Proportional Hadamard Fractional Integral Operator

    • Authors: Vaijanath L. Chinchane, Asha B. Nale, Satish K. Panchal, Christophe Chesneau, Amol D. Khandagale
      First page: 266
      Abstract: The main objective of this paper is to use the generalized proportional Hadamard fractional integral operator to establish some new fractional integral inequalities for extended Chebyshev functionals. In addition, we investigate some fractional integral inequalities for positive continuous functions by employing a generalized proportional Hadamard fractional integral operator. The findings of this study are theoretical but have the potential to help solve additional practical problems in mathematical physics, statistics, and approximation theory.
      Citation: Axioms
      PubDate: 2022-06-01
      DOI: 10.3390/axioms11060266
      Issue No: Vol. 11, No. 6 (2022)
       
  • Axioms, Vol. 11, Pages 267: An Avant-Garde Construction for Subclasses of
           Analytic Bi-Univalent Functions

    • Authors: Feras Yousef, Ala Amourah, Basem Aref Frasin, Teodor Bulboacă
      First page: 267
      Abstract: The zero-truncated Poisson distribution is an important and appropriate model for many real-world applications. Here, we exploit the zero-truncated Poisson distribution probabilities to construct a new subclass of analytic bi-univalent functions involving Gegenbauer polynomials. For functions in the constructed class, we explore estimates of Taylor–Maclaurin coefficients a2 and a3, and next, we solve the Fekete–Szegő functional problem. A number of new interesting results are presented to follow upon specializing the parameters involved in our main results.
      Citation: Axioms
      PubDate: 2022-06-01
      DOI: 10.3390/axioms11060267
      Issue No: Vol. 11, No. 6 (2022)
       
  • Axioms, Vol. 11, Pages 268: On r-Ideals and m-k-Ideals in BN-Algebras

    • Authors: Sri Gemawati, Musnis Musraini, Abdul Hadi, La Zakaria, Elsi Fitria
      First page: 268
      Abstract: A BN-algebra is a non-empty set X with a binary operation “∗” and a constant 0 that satisfies the following axioms: (B1) x∗x=0, (B2) x∗0=x, and (BN) (x∗y)∗z=(0∗z)∗(y∗x) for all x, y, z ∈X. A non-empty subset I of X is called an ideal in BN-algebra X if it satisfies 0∈X and if y∈I and x∗y∈I, then x∈I for all x,y∈X. In this paper, we define several new ideal types in BN-algebras, namely, r-ideal, k-ideal, and m-k-ideal. Furthermore, some of their properties are constructed. Then, the relationships between ideals in BN-algebra with r-ideal, k-ideal, and m-k-ideal properties are investigated. Finally, the concept of r-ideal homomorphisms is discussed in BN-algebra.
      Citation: Axioms
      PubDate: 2022-06-02
      DOI: 10.3390/axioms11060268
      Issue No: Vol. 11, No. 6 (2022)
       
  • Axioms, Vol. 11, Pages 269: Robust Spectral Clustering Incorporating
           Statistical Sub-Graph Affinity Model

    • Authors: Zhenxian Lin, Jiagang Wang, Chengmao Wu
      First page: 269
      Abstract: Hyperspectral image (HSI) clustering is a challenging work due to its high complexity. Subspace clustering has been proven to successfully excavate the intrinsic relationships between data points, while traditional subspace clustering methods ignore the inherent structural information between data points. This study uses graph convolutional subspace clustering (GCSC) for robust HSI clustering. The model remaps the self-expression of the data to non-Euclidean domains, which can generate a robust graph embedding dictionary. The EKGCSC model can achieve a globally optimal closed-form solution by using a subspace clustering model with the Frobenius norm and a Gaussian kernel function, making it easier to implement, train, and apply. However, the presence of noise can have a noteworthy negative impact on the segmentation performance. To diminish the impact of image noise, the concept of sub-graph affinity is introduced, where each node in the primary graph is modeled as a sub-graph describing the neighborhood around the node. A statistical sub-graph affinity matrix is then constructed based on the statistical relationships between sub-graphs of connected nodes in the primary graph, thus counteracting the uncertainty image noise by using more information. The model used in this work was named statistical sub-graph affinity kernel graph convolutional subspace clustering (SSAKGCSC). Experiment results on Salinas, Indian Pines, Pavia Center, and Pavia University data sets showed that the SSAKGCSC model can achieve improved segmentation performance and better noise resistance ability.
      Citation: Axioms
      PubDate: 2022-06-05
      DOI: 10.3390/axioms11060269
      Issue No: Vol. 11, No. 6 (2022)
       
  • Axioms, Vol. 11, Pages 270: k-Path-Connectivity of Completely Balanced
           Tripartite Graphs

    • Authors: Pi Wang, Shasha Li, Xiaoxue Gao
      First page: 270
      Abstract: For a graph G=(V,E) and a set S⊆V(G) of a size at least 2, a path in G is said to be an S-path if it connects all vertices of S. Two S-paths P1 and P2 are said to be internally disjoint if E(P1)∩E(P2)=∅ and V(P1)∩V(P2)=S; that is, they share no vertices and edges apart from S. Let πG(S) denote the maximum number of internally disjoint S-paths in G. The k-path-connectivity πk(G) of G is then defined as the minimum πG(S), where S ranges over all k-subsets of V(G). In this paper, we study the k-path-connectivity of the complete balanced tripartite graph Kn,n,n and obtain πkKn,n,n=2nk−1 for 3≤k≤n.
      Citation: Axioms
      PubDate: 2022-06-05
      DOI: 10.3390/axioms11060270
      Issue No: Vol. 11, No. 6 (2022)
       
  • Axioms, Vol. 11, Pages 271: Solvability of Conformable Type Frictionless
           Contact Problem via Hemivariational Inequalities

    • Authors: Jianwei Hao, Jinrong Wang, Jiangfeng Han
      First page: 271
      Abstract: In this paper, we study a class of conformable frictionless contact problems with the surface traction driven by the conformable impulsive differential equation. The existence of a mild solution for conformable impulsive hemivariational inequality is obtained by the Rothe method, subjectivity of multivalued pseudomonotone operators and the property of the conformable derivative. Notice that we imply some new fractional viscoelastic constitutive laws.
      Citation: Axioms
      PubDate: 2022-06-05
      DOI: 10.3390/axioms11060271
      Issue No: Vol. 11, No. 6 (2022)
       
  • Axioms, Vol. 11, Pages 272: On a Class of Positive Definite Operators and
           Their Application in Fractional Calculus

    • Authors: Temirkhan Aleroev
      First page: 272
      Abstract: This paper is devoted to the spectral analysis of one class of integral operators, associated with the boundary value problems for differential equations of fractional order. Approximation matrices are also investigated. In particular, the positive definiteness of the studied operators is shown, which makes it possible to select areas in the complex plane where there are no eigenvalues of these operators.
      Citation: Axioms
      PubDate: 2022-06-05
      DOI: 10.3390/axioms11060272
      Issue No: Vol. 11, No. 6 (2022)
       
  • Axioms, Vol. 11, Pages 273: Topological and Geometrical Properties of
           k-Symplectic Structures

    • Authors: Essabab Said, Fanich El Mokhtar, Awane Azzouz
      First page: 273
      Abstract: We study new geometrical and topological aspects of polarized k-symplectic manifolds. In addition, we study the De Rham cohomology groups of the k-symplectic group. In this work, we pay particular attention to the problem of the orientation of polarized k-symplectic manifolds in a way analogous to symplectic manifolds which are all orientable.
      Citation: Axioms
      PubDate: 2022-06-06
      DOI: 10.3390/axioms11060273
      Issue No: Vol. 11, No. 6 (2022)
       
  • Axioms, Vol. 11, Pages 274: Homogeneity of Complex Fuzzy Operations

    • Authors: Bo Hu, Wei Wu, Songsong Dai
      First page: 274
      Abstract: The homogeneity of binary functions on the unit interval [0, 1] is a very useful property in many real practical applications. This paper studies the homogeneity of binary functions on the unit circle of the complex plane. The homogeneity is a generalization of both rotational invariance and ratio scale invariance for complex fuzzy operations. We show that a binary function is homogeneous if and only if it is both rotationally invariant and ratio scale invariant. Moreover, we consider the simplification of the homogeneity for complex fuzzy binary operators.
      Citation: Axioms
      PubDate: 2022-06-06
      DOI: 10.3390/axioms11060274
      Issue No: Vol. 11, No. 6 (2022)
       
  • Axioms, Vol. 11, Pages 275: A Novel Multi-Criteria Decision-Making Method
           Based on Rough Sets and Fuzzy Measures

    • Authors: Jingqian Wang, Xiaohong Zhang
      First page: 275
      Abstract: Rough set theory provides a useful tool for data analysis, data mining and decision making. For multi-criteria decision making (MCDM), rough sets are used to obtain decision rules by reducing attributes and objects. However, different reduction methods correspond to different rules, which will influence the decision result. To solve this problem, we propose a novel method for MCDM based on rough sets and a fuzzy measure in this paper. Firstly, a type of non-additive measure of attributes is presented by the importance degree in rough sets, which is a fuzzy measure and called an attribute measure. Secondly, for a decision information system, the notion of the matching degree between two objects is presented under an attribute. Thirdly, based on the notions of the attribute measure and matching degree, a Choquet integral is constructed. Moreover, a novel MCDM method is presented by the Choquet integral. Finally, the presented method is compared with other methods through a numerical example, which is used to illustrate the feasibility and effectiveness of our method.
      Citation: Axioms
      PubDate: 2022-06-06
      DOI: 10.3390/axioms11060275
      Issue No: Vol. 11, No. 6 (2022)
       
  • Axioms, Vol. 11, Pages 276: Interval Type-3 Fuzzy Control for Automated
           Tuning of Image Quality in Televisions

    • Authors: Oscar Castillo, Juan R. Castro, Patricia Melin
      First page: 276
      Abstract: In this article, an intelligent system utilizing type-3 fuzzy logic for automated image quality tuning in televisions is presented. The tuning problem can be formulated as controlling the television imaging system to achieve the requirements of production quality. Previously, the tuning process has been carried out by experts, by manually adjusting the television imaging system on production lines to meet the quality control standards. In this approach, interval type-3 fuzzy logic is utilized with the goal of automating the tuning of televisions manufactured on production lines. An interval type-3 fuzzy approach for image tuning is proposed, so that the best image quality is obtained and, in this way, meet quality requirements. A system based on type-3 fuzzy control is implemented with good simulation results. The validation of the type-3 fuzzy approach is made by comparing the results with human experts on the process of electrical tuning of televisions. The key contribution is the utilization of type-3 fuzzy in the image tuning application, which has not been reported previously in the literature.
      Citation: Axioms
      PubDate: 2022-06-09
      DOI: 10.3390/axioms11060276
      Issue No: Vol. 11, No. 6 (2022)
       
  • Axioms, Vol. 11, Pages 277: Super Connected Direct Product of Graphs and
           Cycles

    • Authors: Jiaqiong Yin, Yingzhi Tian
      First page: 277
      Abstract: The topology of an interconnection network can be modeled by a graph G=(V(G),E(G)). The connectivity of graph G is a parameter used to measure the reliability of a corresponding network. The direct product is an important graph product. This paper mainly focuses on the super connectedness of the direct product of graphs and cycles. The connectivity of G, denoted by κ(G), is the size of a minimum vertex set S⊆V(G) such that G−S is not connected or has only one vertex. The graph G is said to be super connected, simply super-κ, if every minimum vertex cut is the neighborhood of a vertex with minimum degree. The direct product of two graphs G and H, denoted by G×H, is the graph with vertex set V(G×H)=V(G)×V(H) and edge set E(G×H)={(u1,v1)(u2,v2) u1u2∈E(G),v1v2∈E(H)}. In this paper, we give some sufficient conditions for the direct product G×Cn to be super connected, where Cn is the cycle on n vertices. Furthermore, those sufficient conditions are the best possible.
      Citation: Axioms
      PubDate: 2022-06-09
      DOI: 10.3390/axioms11060277
      Issue No: Vol. 11, No. 6 (2022)
       
  • Axioms, Vol. 11, Pages 278: On the Laplacian, the Kirchhoff Index, and the
           Number of Spanning Trees of the Linear Pentagonal Derivation Chain

    • Authors: Yue Tu, Xiaoling Ma, Yuqing Zhang, Junyu Ren
      First page: 278
      Abstract: Let Pn be a pentagonal chain with 2n pentagons in which two pentagons with two edges in common can be regarded as adding one vertex and two edges to a hexagon. Thus, the linear pentagonal derivation chains QPn represent the graph obtained by attaching four-membered rings to every two pentagons of Pn. In this article, the Laplacian spectrum of QPn consisting of the eigenvalues of two symmetric matrices is determined. Next, the formulas for two graph invariants that can be represented by the Laplacian spectrum, namely, the Kirchhoff index and the number of spanning trees, are studied. Surprisingly, the Kirchhoff index is almost one half of the Wiener index of a linear pentagonal derivation chain QPn.
      Citation: Axioms
      PubDate: 2022-06-09
      DOI: 10.3390/axioms11060278
      Issue No: Vol. 11, No. 6 (2022)
       
  • Axioms, Vol. 11, Pages 279: New Inequalities and Generalizations for
           Symmetric Means Induced by Majorization Theory

    • Authors: Huan-Nan Shi, Wei-Shih Du
      First page: 279
      Abstract: In this paper, the authors study new inequalities and generalizations for symmetric means and give new proofs for some known results by applying majorization theory.
      Citation: Axioms
      PubDate: 2022-06-09
      DOI: 10.3390/axioms11060279
      Issue No: Vol. 11, No. 6 (2022)
       
  • Axioms, Vol. 11, Pages 280: Application of Deep Learning and Neural
           Network to Speeding Ticket and Insurance Claim Count Data

    • Authors: Jong-Min Kim, Jihun Kim, Il Do Ha
      First page: 280
      Abstract: With the popularity of big data analysis with insurance claim count data, diverse regression models for count response variable have been developed. However, there is a multicollinearlity issue with multivariate input variables to the count response regression models. Recently, deep learning and neural network models for count response have been proposed, and a Keras and Tensorflow-based deep learning model has been also proposed. To apply the deep learning and neural network models to non-normal insurance claim count data, we perform the root mean square error accuracy comparison of gradient boosting machines (a popular machine learning regression tree algorithm), principal component analysis (PCA)-based Poisson regression, PCA-based negative binomial regression, and PCA-based zero inflated poisson regression to avoid the multicollinearity of multivariate input variables with the simulated normal distribution data and the non-normal simulated data combined with normally distributed data, binary data, copula-based asymmetrical data, and two real data sets, which consist of speeding ticket and Singapore insurance claim count data.
      Citation: Axioms
      PubDate: 2022-06-10
      DOI: 10.3390/axioms11060280
      Issue No: Vol. 11, No. 6 (2022)
       
  • Axioms, Vol. 11, Pages 281: Nonoscillation and Oscillation Criteria for a
           Class of Second-Order Nonlinear Neutral Delay Differential Equations with
           Positive and Negative Coefficients

    • Authors: Rongrong Guo, Qingdao Huang, Haifeng Tian
      First page: 281
      Abstract: In this paper, we investigate some nonoscillatory and oscillatory solutions for a class of second-order nonlinear neutral delay differential equations with positive and negative coefficients. By means of the method of contraction mapping principle and some integral inequality techniques, we extend the recent results provided in the literature.
      Citation: Axioms
      PubDate: 2022-06-10
      DOI: 10.3390/axioms11060281
      Issue No: Vol. 11, No. 6 (2022)
       
  • Axioms, Vol. 11, Pages 282: The Existence of Radial Solutions to the
           Schrödinger System Containing a Nonlinear Operator

    • Authors: Guotao Wang, Zhuobin Zhang, Zedong Yang
      First page: 282
      Abstract: In this paper, we investigate a class of nonlinear Schrödinger systems containing a nonlinear operator under Osgood-type conditions. By employing the iterative technique, the existence conditions for entire positive radial solutions of the above problem are given under the cases where components μ and ν are bounded, μ and ν are blow-up, and one of the components is bounded, while the other is blow-up. Finally, we present two examples to verify our results.
      Citation: Axioms
      PubDate: 2022-06-10
      DOI: 10.3390/axioms11060282
      Issue No: Vol. 11, No. 6 (2022)
       
  • Axioms, Vol. 11, Pages 283: Controllability of a Class of Impulsive
           ψ-Caputo Fractional Evolution Equations of Sobolev Type

    • Authors: Qing Yang, Chuanzhi Bai, Dandan Yang
      First page: 283
      Abstract: In this paper, we investigate the controllability of a class of impulsive ψ-Caputo fractional evolution equations of Sobolev type in Banach spaces. Sufficient conditions are presented by two new characteristic solution operators, fractional calculus, and Schauder fixed point theorem. Our works are generalizations and continuations of the recent results about controllability of a class of impulsive ψ-Caputo fractional evolution equations. Finally, an example is given to illustrate the effectiveness of the main results.
      Citation: Axioms
      PubDate: 2022-06-10
      DOI: 10.3390/axioms11060283
      Issue No: Vol. 11, No. 6 (2022)
       
  • Axioms, Vol. 11, Pages 284: Evaluating the Digital Transformation
           Performance of Retail by the DEA Approach

    • Authors: Ling-Jing Kao, Chih-Chou Chiu, Hung-Tse Lin, Yun-Wei Hung, Cheng-Chin Lu
      First page: 284
      Abstract: In recent years, under the impact of digitization, all industries around the world have undergone unprecedented changes. Such changes have not only altered people’s consumption behavior but have also forced enterprises to accelerate the pace of digitization and actively start digital transformation. In this study, a literature review and focus group interview (FGI) were used to develop the dimensions and criteria to assess enterprise digital transformation status. To illustrate the digital transformation criteria proposed in this research, the retail industry was used as an example to measure the overall digital transformation performance by data envelopment analysis (DEA). The results show that the poor technical efficiency demonstrated by a vendor was not only due to the gradually decreasing returns to scale of the market; a decline in pure technical efficiency was also a contributor. In addition to adjusting their production on the basis of market conditions, vendors should properly manage their internal operations and pay attention to their resource and scale allocations to prevent reductions in their pure technical efficiency.
      Citation: Axioms
      PubDate: 2022-06-13
      DOI: 10.3390/axioms11060284
      Issue No: Vol. 11, No. 6 (2022)
       
  • Axioms, Vol. 11, Pages 285: Some Generalized Euclidean Operator Radius
           Inequalities

    • Authors: Mohammad W. Alomari, Khalid Shebrawi, Christophe Chesneau
      First page: 285
      Abstract: In this work, some generalized Euclidean operator radius inequalities are established. Refinements of some well-known results are provided. Among others, some bounds in terms of the Cartesian decomposition of a given Hilbert space operator are proven.
      Citation: Axioms
      PubDate: 2022-06-13
      DOI: 10.3390/axioms11060285
      Issue No: Vol. 11, No. 6 (2022)
       
  • Axioms, Vol. 11, Pages 286: A Selection Principle and Products in
           Topological Groups

    • Authors: Marion Scheepers
      First page: 286
      Abstract: We consider the preservation under products, finite powers, and forcing of a selection-principle-based covering property of T0 topological groups. Though the paper is partly a survey, it contributes some new information: (1) The product of a strictly o-bounded group with an o-bounded group is an o-bounded group—Corollary 1. (2) In the generic extension by a finite support iteration of ℵ1 Hechler reals the product of any o-bounded group with a ground model ℵ0 bounded group is an o-bounded group—Theorem 11. (3) In the generic extension by a countable support iteration of Mathias reals the product of any o-bounded group with a ground model ℵ0 bounded group is an o-bounded group—Theorem 12.
      Citation: Axioms
      PubDate: 2022-06-13
      DOI: 10.3390/axioms11060286
      Issue No: Vol. 11, No. 6 (2022)
       
  • Axioms, Vol. 11, Pages 287: A Story of Computational Science: Colonel
           Titus’ Problem from the 17th Century

    • Authors: Trond Steihaug
      First page: 287
      Abstract: Experimentation and the evaluation of algorithms have a long history in algebra. In this paper we follow a single test example over more than 250 years. In 1685, John Wallis published A treatise of algebra, both historical and practical, containing a solution of Colonel Titus’ problem that was proposed to him around 1650. The Colonel Titus problem consists of three algebraic quadratic equations in three unknowns, which Wallis transformed into the problem of finding the roots of a fourth-order (quartic) polynomial. When Joseph Raphson published his method in 1690, he demonstrated the method on 32 algebraic equations and one of the examples was this quartic equation. Edmund Halley later used the same polynomial as an example for his new methods in 1694. Although Wallis used the method of Vietè, which is a digit–by–digit method, the more efficient methods of Halley and Raphson are clearly demonstrated in the works by Raphson and Halley. For more than 250 years the quartic equation has been used as an example in a wide range of solution methods for nonlinear equations. This paper provides an overview of the Colonel Titus problem and the equation first derived by Wallis. The quartic equation has four positive roots and the equation has been found to be very useful for analyzing the number of roots and finding intervals for the individual roots, in the Cardan–Ferrari direct approach for solving quartic equations, and in Sturm’s method of determining the number of real roots of an algebraic equation. The quartic equation, together with two other algebraic equations, have likely been the first set of test examples used to compare different iteration methods of solving algebraic equations.
      Citation: Axioms
      PubDate: 2022-06-14
      DOI: 10.3390/axioms11060287
      Issue No: Vol. 11, No. 6 (2022)
       
  • Axioms, Vol. 11, Pages 288: On Unique Factorization Modules: A Submodule
           Approach

    • Authors: Sri Wahyuni, Hidetoshi Marubayashi, Iwan Ernanto, I Putu Yudi Prabhadika
      First page: 288
      Abstract: Let M be a torsion-free module over an integral domain D. We define a concept of a unique factorization module in terms of v-submodules of M. If M is a unique factorization module (UFM), then D is a unique factorization domain. However, the converse situation is not necessarily to be held, and we give four different characterizations of unique factorization modules. Further, it is shown that the concept of the UFM is equivalent to Nicolas’s UFM, which is defined in terms of irreducible elements of D and M.
      Citation: Axioms
      PubDate: 2022-06-14
      DOI: 10.3390/axioms11060288
      Issue No: Vol. 11, No. 6 (2022)
       
  • Axioms, Vol. 11, Pages 289: Pipeline Corrosion Prediction Using the Grey
           Model and Artificial Bee Colony Algorithm

    • Authors: Shiguo Li, Hualong Du, Qiuyu Cui, Pengfei Liu, Xin Ma, He Wang
      First page: 289
      Abstract: Pipeline corrosion prediction (PCP) is an important technology for pipeline maintenance and management. How to accurately predict pipeline corrosion is a challenging task. To address the drawback of the poor prediction accuracy of the grey model (GM(1,1)), this paper proposes a method named ETGM(1,1)-RABC. The proposed method consists of two parts. First, the exponentially transformed grey model (ETGM(1,1)) is an improvement of the GM(1,1), in which exponential transformation (ET) is used to preprocess the raw data. Next, dynamic coefficients, instead of background fixed coefficients, are optimized by the reformative artificial bee colony (RABC) algorithm, which is a variation of the artificial bee colony (ABC) algorithm. Experiments are performed on actual pipe corrosion data, and four different methods are included in the comparative study, including GM(1,1), ETGM(1,1), and three ETGM(1,1)-ABC variants. The results show that the proposed method proves to be superior for the PCP in terms of Taylor diagram and absolute error.
      Citation: Axioms
      PubDate: 2022-06-14
      DOI: 10.3390/axioms11060289
      Issue No: Vol. 11, No. 6 (2022)
       
  • Axioms, Vol. 11, Pages 290: Some Cardinal and Geometric Properties of the
           Space of Permutation Degree

    • Authors: Ljubiša D. R. Kočinac, Farkhod G. Mukhamadiev, Anvar K. Sadullaev
      First page: 290
      Abstract: This paper is devoted to the investigation of cardinal invariants such as the hereditary density, hereditary weak density, and hereditary Lindelöf number. The relation between the spread and the extent of the space SP2(R,τ(A)) of permutation degree of the Hattori space is discussed. In particular, it is shown that the space SP2(R,τS) contains a closed discrete subset of cardinality c. Moreover, it is shown that the functor SPGn preserves the homotopy and the retraction of topological spaces. In addition, we prove that if the spaces X and Y are homotopically equivalent, then the spaces SPGnX and SPGnY are also homotopically equivalent. As a result, it has been proved that the functor SPGn is a covariant homotopy functor.
      Citation: Axioms
      PubDate: 2022-06-14
      DOI: 10.3390/axioms11060290
      Issue No: Vol. 11, No. 6 (2022)
       
  • Axioms, Vol. 11, Pages 291: Characterizations of Matrix Equalities for
           Generalized Inverses of Matrix Products

    • Authors: Yongge Tian
      First page: 291
      Abstract: This paper considers how to construct and describe matrix equalities that are composed of algebraic operations of matrices and their generalized inverses. We select a group of known and new reverse-order laws for generalized inverses of several matrix products and derive various necessary and sufficient conditions for them to hold using the matrix rank method and the block matrix method.
      Citation: Axioms
      PubDate: 2022-06-14
      DOI: 10.3390/axioms11060291
      Issue No: Vol. 11, No. 6 (2022)
       
  • Axioms, Vol. 11, Pages 292: Multitask Learning Based on Least Squares
           Support Vector Regression for Stock Forecast

    • Authors: Heng-Chang Zhang, Qing Wu, Fei-Yan Li, Hong Li
      First page: 292
      Abstract: Various factors make stock market forecasting difficult and arduous. Single-task learning models fail to achieve good results because they ignore the correlation between multiple related tasks. Multitask learning methods can capture the cross-correlation among subtasks and achieve a satisfactory learning effect by training all tasks simultaneously. With this motivation, we assume that the related tasks are close enough to share a common model whereas having their own independent models. Based on this hypothesis, we propose a multitask learning least squares support vector regression (MTL-LS-SVR) algorithm, and an extension, EMTL-LS-SVR. Theoretical analysis shows that these models can be converted to linear systems. A Krylov-Cholesky algorithm is introduced to determine the optimal solutions of the models. We tested the proposed models by applying them to forecasts of the Chinese stock market index trend and the stock prices of five stated-owned banks. The experimental results demonstrate their validity.
      Citation: Axioms
      PubDate: 2022-06-15
      DOI: 10.3390/axioms11060292
      Issue No: Vol. 11, No. 6 (2022)
       
  • Axioms, Vol. 11, Pages 293: Parameter Estimation of the Exponentiated
           Pareto Distribution Using Ranked Set Sampling and Simple Random Sampling

    • Authors: Hossein Jabbari Khamnei, Ieva Meidute-Kavaliauskiene, Masood Fathi, Asta Valackienė, Shahryar Ghorbani
      First page: 293
      Abstract: In this paper, we have considered that ranked set sampling is able to estimate the parameters of exponentiated Pareto distribution. The method with which the maximum likelihood estimators for the parameters of exponentiated Pareto distribution is studied is numerical since there is no presence or possibility of a closed-form at the hands of estimators or any other intellectual. The numerical approach is a well-suited one for this study as there has been struggles in achieving it with any other technique. In order to compare the different sampling methods, simulation studies are performed as the main technique. As for the illustrative purposes, analysis of a simulated dataset is desired for the objective of the presentation. The conclusion that we can reach based on these is that the estimators based on the ranked set sample have far better efficiency than the simple random sample at the same sample size.
      Citation: Axioms
      PubDate: 2022-06-15
      DOI: 10.3390/axioms11060293
      Issue No: Vol. 11, No. 6 (2022)
       
  • Axioms, Vol. 11, Pages 294: RbfDeSolver: A Software Tool to Approximate
           Differential Equations Using Radial Basis Functions

    • Authors: Ioannis G. Tsoulos, Alexandros Tzallas, Evangelos Karvounis
      First page: 294
      Abstract: A new method for solving differential equations is presented in this work. The solution of the differential equations is done by adapting an artificial neural network, RBF, to the function under study. The adaptation of the parameters of the network is done with a hybrid genetic algorithm. In addition, this text presents in detail the software developed for the above method in ANSI C++. The user can code the underlying differential equation either in C++ or in Fortran format. The method was applied to a wide range of test functions of different types and the results are presented and analyzed in detail.
      Citation: Axioms
      PubDate: 2022-06-16
      DOI: 10.3390/axioms11060294
      Issue No: Vol. 11, No. 6 (2022)
       
  • Axioms, Vol. 11, Pages 295: Existence Results for a Multipoint Fractional
           Boundary Value Problem in the Fractional Derivative Banach Space

    • Authors: Djalal Boucenna, Amar Chidouh, Delfim F. M. Torres
      First page: 295
      Abstract: We study a class of nonlinear implicit fractional differential equations subject to nonlocal boundary conditions expressed in terms of nonlinear integro-differential equations. Using the Krasnosel’skii fixed-point theorem we prove, via the Kolmogorov–Riesz criteria, the existence of solutions. The existence results are established in a specific fractional derivative Banach space and they are illustrated by two numerical examples.
      Citation: Axioms
      PubDate: 2022-06-16
      DOI: 10.3390/axioms11060295
      Issue No: Vol. 11, No. 6 (2022)
       
  • Axioms, Vol. 11, Pages 296: Public Opinion Spread and Guidance Strategy
           under COVID-19: A SIS Model Analysis

    • Authors: Ge You, Shangqian Gan, Hao Guo, Abd Alwahed Dagestani
      First page: 296
      Abstract: Both the suddenness and seriousness of COVID-19 have caused a variety of public opinions on social media, which becomes the focus of social attention. This paper aims to analyze the strategies regarding the prevention and guidance of public opinion spread under COVID-19 in social networks from the perspective of the emotional characteristics of user texts. Firstly, a model is established to mine text-based emotional tendency based on the Susceptible-Infectious-Susceptible (SIS) model. In addition, a mathematical and simulation analysis of the model is presented. Finally, an empirical study based on the data of microblog contents regarding COVID-19 public opinion in the Sina Weibo platform from January to March 2020 is conducted to analyze the factors that boost and hinder COVID-19 public opinion. The results show that when positive emotion is higher than 0.8, the spread of negative public opinion can be blocked. When the negative emotion and neutral emotion are both below 0.2, the spread of COVID-19 public opinion would be weakened. To accurately guide public opinion on COVID-19, the government authorities should establish a public opinion risk evaluation and an early warning mechanism. Platforms should strengthen public opinion supervision and users should improve their media literacy. The media organizations should insist on positive reporting, improve social cohesion, and guide the trend of public opinion.
      Citation: Axioms
      PubDate: 2022-06-17
      DOI: 10.3390/axioms11060296
      Issue No: Vol. 11, No. 6 (2022)
       
  • Axioms, Vol. 11, Pages 297: Context-Free Grammars for Several Triangular
           Arrays

    • Authors: Roberta Rui Zhou, Jean Yeh, Fuquan Ren
      First page: 297
      Abstract: In this paper, we present a unified grammatical interpretation of the numbers that satisfy a kind of four-term recurrence relation, including the Bell triangle, the coefficients of modified Hermite polynomials, and the Bessel polynomials. Additionally, as an application, a criterion for real zeros of row-generating polynomials is also presented.
      Citation: Axioms
      PubDate: 2022-06-20
      DOI: 10.3390/axioms11060297
      Issue No: Vol. 11, No. 6 (2022)
       
  • Axioms, Vol. 11, Pages 298: Dynamic Behaviors of an Obligate Commensal
           Symbiosis Model with Crowley–Martin Functional Responses

    • Authors: Lili Xu, Yalong Xue, Xiangdong Xie, Qifa Lin
      First page: 298
      Abstract: A two species obligate commensal symbiosis model with Crowley–Martin functional response was proposed and studied in this paper. For an autonomous case, local and global dynamic behaviors of the system were investigated, respectively. The conditions that ensure the existence of the positive equilibrium is coincidentla to the conditions of global stability of a positive equilibrium. For nonautonomous cases, persistent and extinction properties of the system are investigated.
      Citation: Axioms
      PubDate: 2022-06-20
      DOI: 10.3390/axioms11060298
      Issue No: Vol. 11, No. 6 (2022)
       
  • Axioms, Vol. 11, Pages 299: A New Survey of Measures of Noncompactness and
           Their Applications

    • Authors: Moosa Gabeleh, Eberhard Malkowsky, Mohammad Mursaleen, Vladimir Rakočević
      First page: 299
      Abstract: We present a survey of the theory of measures of noncompactness and discuss some fixed point theorems of Darbo’s type. We apply the technique of measures of noncompactness to the characterization of classes of compact operators between certain sequence spaces, in solving infinite systems of integral equations in some sequence spaces. We also present some recent results related to the existence of best proximity points (pairs) for some classes of cyclic and noncyclic condensing operators in Banach spaces equipped with a suitable measure of noncompactness. Finally, we discuss the existence of an optimal solution for systems of integro–differentials.
      Citation: Axioms
      PubDate: 2022-06-20
      DOI: 10.3390/axioms11060299
      Issue No: Vol. 11, No. 6 (2022)
       
  • Axioms, Vol. 11, Pages 220: New Fuzzy Extensions on Binomial Distribution

    • Authors: Gia Sirbiladze, Janusz Kacprzyk, Teimuraz Manjafarashvili, Bidzina Midodashvili, Bidzina Matsaberidze
      First page: 220
      Abstract: The use of discrete probabilistic distributions is relevant to many practical tasks, especially in present-day situations where the data on distribution are insufficient and expert knowledge and evaluations are the only instruments for the restoration of probability distributions. However, in such cases, uncertainty arises, and it becomes necessary to build suitable approaches to overcome it. In this direction, this paper discusses a new approach of fuzzy binomial distributions (BDs) and their extensions. Four cases are considered: (1) When the elementary events are fuzzy. Based on this information, the probabilistic distribution of the corresponding fuzzy-random binomial variable is calculated. The conditions of restrictions on this distribution are obtained, and it is shown that these conditions depend on the ratio of success and failure of membership levels. The formulas for the generating function (GF) of the constructed distribution and the first and second order moments are also obtained. The Poisson distribution is calculated as the limit case of a fuzzy-random binomial experiment. (2) When the number of successes is of a fuzzy nature and is represented as a fuzzy subset of the set of possible success numbers. The formula for calculating the probability of convolution of binomial dependent fuzzy events is obtained, and the corresponding GF is built. As a result, the scheme for calculating the mathematical expectation of the number of fuzzy successes is defined. (3) When the spectrum of the extended distribution is fuzzy. The discussion is based on the concepts of a fuzzy-random event and its probability, as well as the notion of fuzzy random events independence. The fuzzy binomial upper distribution is specifically considered. In this case the fuzziness is represented by the membership levels of the binomial and non-binomial events of the complete failure complex. The GF of the constructed distribution and the first-order moment of the distribution are also calculated. Sufficient conditions for the existence of a limit distribution and a Poisson distribution are also obtained. (4) As is known, based on the analysis of lexical material, the linguistic spectrum of the statistical process of word-formation becomes two-component when switching to vocabulary. For this, two variants of the hybrid fuzzy-probabilistic process are constructed, which can be used in the analysis of the linguistic spectrum of the statistical process of word-formation. A fuzzy extension of standard Fuchs distribution is also presented, where the fuzziness is reflected in the growing numbers of failures. For better representation of the results, the examples of fuzzy BD are illustrated in each section.
      Citation: Axioms
      PubDate: 2022-05-09
      DOI: 10.3390/axioms11050220
      Issue No: Vol. 11, No. 5 (2022)
       
  • Axioms, Vol. 11, Pages 221: Aspects of Differential Calculus Related to
           Infinite-Dimensional Vector Bundles and Poisson Vector Spaces

    • Authors: Helge Glöckner
      First page: 221
      Abstract: We prove various results in infinite-dimensional differential calculus that relate the differentiability properties of functions and associated operator-valued functions (e.g., differentials). The results are applied in two areas: (1) in the theory of infinite-dimensional vector bundles, to construct new bundles from given ones, such as dual bundles, topological tensor products, infinite direct sums, and completions (under suitable hypotheses); (2) in the theory of locally convex Poisson vector spaces, to prove continuity of the Poisson bracket and continuity of passage from a function to the associated Hamiltonian vector field. Topological properties of topological vector spaces are essential for the studies, which allow the hypocontinuity of bilinear mappings to be exploited. Notably, we encounter kR-spaces and locally convex spaces E such that E×E is a kR-space.
      Citation: Axioms
      PubDate: 2022-05-09
      DOI: 10.3390/axioms11050221
      Issue No: Vol. 11, No. 5 (2022)
       
  • Axioms, Vol. 11, Pages 222: Exact Criteria for the Existence of a Moving
           Singular Point in a Complex Domain for a Nonlinear Differential
           Third-Degree Equation with a Polynomial Seventh-Degree Right-Hand Side

    • Authors: Victor Orlov, Magomedyusuf Gasanov
      First page: 222
      Abstract: Earlier, the authors formulated and proved interval and point criteria for the existence of moving singular points of a third-degree nonlinear differential equation with a polynomial seventh-degree right-hand side for a real domain. For the complex domain, these criteria are associated with specificity of transition to phase spaces. Necessary as well as necessary and sufficient conditions for the existence of moving singular points are obtained. The results of these studies are the basis of the algorithm for obtaining moving singular points of nonlinear differential equations in the complex domain. The results of this paper allow us to expand the classes of the studied nonlinear differential equations with moving peculiarities.
      Citation: Axioms
      PubDate: 2022-05-10
      DOI: 10.3390/axioms11050222
      Issue No: Vol. 11, No. 5 (2022)
       
  • Axioms, Vol. 11, Pages 223: Co-Training Method Based on Semi-Decoupling
           Features for MOOC Learner Behavior Prediction

    • Authors: Huanhuan Wang, Libo Xu, Zhenrui Huang, Jiagong Wang
      First page: 223
      Abstract: Facing the problem of massive unlabeled data and limited labeled samples, semi-supervised learning is favored, especially co-training. Standard co-training requires sufficiently redundant and conditionally independent dual views; however, in fact, few dual views exist that satisfy this condition. To solve this problem, we propose a co-training method based on semi-decoupling features, that is, semi-decoupling features based on a known single view and then constructing independent and redundant dual views: (1) take a small number of important features as shared features of the dual views according to the importance of the features; (2) separate the remaining features one by one or in small batches according to the correlation between the features to make “divergent” features of the dual views; (3) combine the shared features and the “divergent” features to construct dual views. In this paper, the experimental dataset was from the edX dataset jointly released by Harvard University and MIT; the evaluation metrics adopted F1, Precision, and Recall. The analysis methods included three experiments: multiple models, iterations, and hyperparameters. The experimental results show that the effect of this model on MOOC learner behavior prediction was better than the other models, and the best prediction result was obtained in iteration 2. These all verify the effectiveness and superiority of this algorithm and provide a scientific and feasible reference for the development of the future education industry.
      Citation: Axioms
      PubDate: 2022-05-11
      DOI: 10.3390/axioms11050223
      Issue No: Vol. 11, No. 5 (2022)
       
  • Axioms, Vol. 11, Pages 224: Krein’s Theorem in the Context of
           Topological Abelian Groups

    • Authors: Tayomara Borsich, Xabier Domínguez, Elena Martín-Peinador
      First page: 224
      Abstract: A topological abelian group G is said to have the quasi-convex compactness property (briefly, qcp) if the quasi-convex hull of every compact subset of G is again compact. In this paper we prove that there exist locally quasi-convex metrizable complete groups G which endowed with the weak topology associated to their character groups G∧, do not have the qcp. Thus, Krein’s Theorem, a well known result in the framework of locally convex spaces, cannot be fully extended to locally quasi-convex groups. Some features of the qcp are also studied.
      Citation: Axioms
      PubDate: 2022-05-12
      DOI: 10.3390/axioms11050224
      Issue No: Vol. 11, No. 5 (2022)
       
  • Axioms, Vol. 11, Pages 225: Tensor Product of Operators Satisfying
           Zariouh’s Property (gaz), and Stability under Perturbations

    • Authors: Elvis Aponte, Narayanapillai Jayanthi, Domingo Quiroz, Ponraj Vasanthakumar
      First page: 225
      Abstract: For bounded linear operators defined on complex infinite-dimensional Banach space, H. Zariouh, in an article (Property (gz) for bounded linear operators, (2013)) introduced and studied the property (gaz). In this study, through techniques using the local spectral theory of operators, we discover the sufficient conditions that allow the transfer of the property (gaz) from two tensor factors T and S to their tensor product T⊗S. The stability of the property (gaz) in the tensor product under perturbations is also investigated. The theory is exemplified by considering suitable classes of operators such as shift operators, convolution operators, and m-invertible contractions.
      Citation: Axioms
      PubDate: 2022-05-12
      DOI: 10.3390/axioms11050225
      Issue No: Vol. 11, No. 5 (2022)
       
  • Axioms, Vol. 11, Pages 226: A Note on the Reverse Order Law for g-Inverse
           of Operator Product

    • Authors: Yingying Qin, Zhiping Xiong
      First page: 226
      Abstract: The generalized inverse has many important applications in aspects of the theoretical research of matrices and statistics. One of the core problems of the generalized inverse is finding the necessary and sufficient conditions of the reverse order laws for the generalized inverse of the operator product. In this paper, we study the reverse order law for the g-inverse of an operator product T1T2T3 using the technique of matrix form of bounded linear operators. In particular, some necessary and sufficient conditions for the inclusion T3{1}T2{1}T1{1} ⊆ (T1T2T3){1} is presented. Moreover, some finite dimensional results are extended to infinite dimensional settings.
      Citation: Axioms
      PubDate: 2022-05-12
      DOI: 10.3390/axioms11050226
      Issue No: Vol. 11, No. 5 (2022)
       
  • Axioms, Vol. 11, Pages 227: Some Generalizations of the Jensen-Type
           Inequalities with Applications

    • Authors: Mirna Rodić
      First page: 227
      Abstract: Motivated by some results about reverses of the Jensen inequality for positive measure, in this paper we give generalizations of those results for real Stieltjes measure dλ which is not necessarily positive using several Green functions. Utilizing these results we define some new mean value theorems of Lagrange and Cauchy types, and derive some new Cauchy-type means.
      Citation: Axioms
      PubDate: 2022-05-13
      DOI: 10.3390/axioms11050227
      Issue No: Vol. 11, No. 5 (2022)
       
  • Axioms, Vol. 11, Pages 228: A Two-Stage Multi-Criteria Supplier Selection
           Model for Sustainable Automotive Supply Chain under Uncertainty

    • Authors: Thanh-Tuan Dang, Ngoc-Ai-Thy Nguyen, Van-Thanh-Tien Nguyen, Le-Thanh-Hieu Dang
      First page: 228
      Abstract: Sustainable supplier selection (SSS) is gaining popularity as a practical method to supply chain sustainability among academics and practitioners. However, in addition to balancing economic, social, and environmental factors, the emergence of the COVID-19 pandemic has affected the selection of long-term suppliers to ensure sustainable supply chains, recover better from the pandemic and effectively respond to any future unprecedented crises. The purpose of this study is to assess and choose a possible supplier based on their capability to adapt to the COVID-19 epidemic in a sustainable manner. For this assessment, a framework based on multi-criteria decision making (MCDM) is provided that integrates spherical fuzzy Analytical Hierarchical Process (SF-AHP) and grey Complex Proportional Assessment (G-COPRAS), in which spherical fuzzy sets and grey numbers are used to express the ambiguous linguistic evaluation statements of experts. In the first stage, the evaluation criteria system is identified through a literature review and experts’ opinions. The SF-AHP is then used to determine the criteria weights. Finally, the G-COPRAS method is utilized to select sustainable suppliers. A case study in the automotive industry in Vietnam is presented to demonstrate the proposed approach’s effectiveness. From the SF-AHP findings, “quality”, “use of personal protective equipment”, “cost/price”, “safety and health practices and wellbeing of suppliers”, and “economic recovery programs” have been ranked as the five most important criteria. From G-COPRAS analysis, THACO Parts (Supplier 02) is the best supplier. A sensitivity study was also conducted to verify the robustness of the proposed model, in which the priority rankings of the best suppliers are very similar. For long-term development and increased competitiveness, industrial businesses must stress the integration of response mechanisms during SSS implementation in the COVID-19 epidemic, according to the findings. This will result in significant cost and resource savings, as well as reduced environmental consequences and a long-term supply chain, independent of the crisis.
      Citation: Axioms
      PubDate: 2022-05-13
      DOI: 10.3390/axioms11050228
      Issue No: Vol. 11, No. 5 (2022)
       
  • Axioms, Vol. 11, Pages 229: The Possibility of Combining and Implementing
           Deep Neural Network Compression Methods

    • Authors: Bratislav Predić, Uroš Vukić, Muzafer Saračević, Darjan Karabašević, Dragiša Stanujkić
      First page: 229
      Abstract: In the paper, the possibility of combining deep neural network (DNN) model compression methods to achieve better compression results was considered. To compare the advantages and disadvantages of each method, all methods were applied to the ResNet18 model for pretraining to the NCT-CRC-HE-100K dataset while using CRC-VAL-HE-7K as the validation dataset. In the proposed method, quantization, pruning, weight clustering, QAT (quantization-aware training), preserve cluster QAT (hereinafter PCQAT), and distillation were performed for the compression of ResNet18. The final evaluation of the obtained models was carried out on a Raspberry Pi 4 device using the validation dataset. The greatest model compression result on the disk was achieved by applying the PCQAT method, whose application led to a reduction in size of the initial model by as much as 45 times, whereas the greatest model acceleration result was achieved via distillation on the MobileNetV2 model. All methods led to the compression of the initial size of the model, with a slight loss in the model accuracy or an increase in the model accuracy in the case of QAT and weight clustering. INT8 quantization and knowledge distillation also led to a significant decrease in the model execution time.
      Citation: Axioms
      PubDate: 2022-05-13
      DOI: 10.3390/axioms11050229
      Issue No: Vol. 11, No. 5 (2022)
       
  • Axioms, Vol. 11, Pages 230: Evaluation of Digital Marketing Technologies
           with Fuzzy Linguistic MCDM Methods

    • Authors: Ngo Quang Trung, Nguyen Van Thanh
      First page: 230
      Abstract: Technology is becoming the tool that changes how people live every day, and the marketing strategies of businesses are also gradually shifting to the industry 4.0 mindset of constant growth and development. Digital marketing has changed human habits of information accessibility, determined their interactions, and witnessed the birth of a variety of new marketing technologies. Marketers are creating digital marketing products and services that enhance the experience for consumers, products, and services that are also delivered through high digital marketing networks. As a result, data sources become more abundant and allow consumers to have more choices. All products, services, technologies, and data are increasingly meeting the needs of consumers, thereby confirming the effectiveness of digital marketing in today’s market. However, the evaluation and selection of digital marketing technology is very complex since it has many conflicting criteria and goals. The multi-criteria decision-making model (MCDM) is a powerful technique widely used for solving this type of problem. Thus, the author proposed a fuzzy linguistic MCDM method for evaluation of digital marketing technologies. After determining the evaluation criteria and alternatives, two MCDM methods, including Spherical Fuzzy Analytic Hierarchy Process (SF-AHP) and Technique for Order Preference by Similarity to Ideal Solution (TOPSIS), are used in the evaluation and selection of digital marketing technologies procedure. Finally, an application is present to demonstrate the potential use of the proposed methodology. The main contribution of this study is to propose a Spherical fuzzy MCDM model to support planners and decision makers in the digital marketing technology evaluation and selection processes. A case study is also performed to showcase the feasibility of the proposed approach.
      Citation: Axioms
      PubDate: 2022-05-13
      DOI: 10.3390/axioms11050230
      Issue No: Vol. 11, No. 5 (2022)
       
  • Axioms, Vol. 11, Pages 231: Taylor’s Formula for Generalized
           Weighted Fractional Derivatives with Nonsingular Kernels

    • Authors: Houssine Zine, El Mehdi Lotfi, Delfim F. M. Torres, Noura Yousfi
      First page: 231
      Abstract: We prove a new Taylor’s theorem for generalized weighted fractional calculus with nonsingular kernels. The proof is based on the establishment of new relations for nth-weighted generalized fractional integrals and derivatives. As an application, new mean value theorems for generalized weighted fractional operators are obtained. Direct corollaries allow one to obtain the recent Taylor’s and mean value theorems for Caputo–Fabrizio, Atangana–Baleanu–Caputo (ABC) and weighted ABC derivatives.
      Citation: Axioms
      PubDate: 2022-05-15
      DOI: 10.3390/axioms11050231
      Issue No: Vol. 11, No. 5 (2022)
       
  • Axioms, Vol. 11, Pages 232: Modeling Preferences through Personality and
           Satisfaction to Guide the Decision Making of a Virtual Agent

    • Authors: Jorge Castro-Rivera, María Lucila Morales-Rodríguez, Nelson Rangel-Valdez, Claudia Gómez-Santillán, Luciano Aguilera-Vázquez
      First page: 232
      Abstract: Satisfaction is relevant for decision makers (DM, Decision Makers). Satisfaction is the feeling produced in individuals by executing actions to satisfy their needs, for example, the payment of debts, jobs, or academic achievements, and the acquisition of goods or services. In the satisfaction literature, some theories model the satisfaction of individuals from job and customer approaches. However, considering personality elements to influence satisfaction and define preferences in strategies that optimize decision making provides the unique characteristics of a DM. These characteristics favor the scope of solutions closer to the satisfaction expectation. Satisfaction theories do not include specific elements of personality and preferences, so integrating these elements will offer more efficient decisions in computable models. In this work, a model of satisfaction with personality characteristics that influence the preferences of a DM is proposed. The proposed model is integrated into a preference-based optimizer that improves the decision-making process of a Virtual Decision Maker (VDM) in an optimization context. The optimization context addressed in this work is the product selection process within a food product shopping problem. An experimental design is proposed that compares two configurations that represent the cognitive part of an agent’s decision process to validate the operation of the proposed model in the context of optimization: (1) satisfaction, personality, and preferences, and (2) personality and preferences. The results show that considering satisfaction and personality in combination with preferences provides solutions closer to the interests of an individual, reflecting a more realistic behavior. Furthermore, this work demonstrates that it is possible to create a configurable model that allows adapting to different aptitudes and reflecting them in a computable model.
      Citation: Axioms
      PubDate: 2022-05-17
      DOI: 10.3390/axioms11050232
      Issue No: Vol. 11, No. 5 (2022)
       
  • Axioms, Vol. 11, Pages 233: Some Upper Bounds for RKHS Approximation by
           Bessel Functions

    • Authors: Mingdang Tian, Baohuai Sheng, Shuhua Wang
      First page: 233
      Abstract: A reproducing kernel Hilbert space (RKHS) approximation problem arising from learning theory is investigated. Some K-functionals and moduli of smoothness with respect to RKHSs are defined with Fourier–Bessel series and Fourier–Bessel transforms, respectively. Their equivalent relation is shown, with which the upper bound estimate for the best RKHS approximation is provided. The convergence rate is bounded with the defined modulus of smoothness, which shows that the RKHS approximation can attain the same approximation ability as that of the Fourier–Bessel series and Fourier–Bessel transform. In particular, it is shown that for a RKHS produced by the Bessel operator, the convergence rate sums up to the bound of a corresponding convolution operator approximation. The investigations show some new applications of Bessel functions. The results obtained can be used to bound the approximation error in learning theory.
      Citation: Axioms
      PubDate: 2022-05-17
      DOI: 10.3390/axioms11050233
      Issue No: Vol. 11, No. 5 (2022)
       
  • Axioms, Vol. 11, Pages 234: Investigation into the Explicit Solutions of
           the Integrable (2+1)-Dimensional Maccari System via the Variational
           Approach

    • Authors: Kang-Jia Wang, Jing Si
      First page: 234
      Abstract: In this paper, the integrable (2+1)-dimensional Maccari system (MS), which can model many complex phenomena in hydrodynamics, plasma physics and nonlinear optics, is investigated by the variational approach (VA). This proposed approach that based on the variational theory and Ritz-like method can construct the explicit solutions via the stationary conditions only taking two steps. Finally, the dynamic behaviors of the solutions are exhibited by choosing the appropriate parameters through the 3-D and density plots. It can be seen that the proposed method is concise and straightforward, and can be adopted to study the travelling wave theory in physics.
      Citation: Axioms
      PubDate: 2022-05-18
      DOI: 10.3390/axioms11050234
      Issue No: Vol. 11, No. 5 (2022)
       
  • Axioms, Vol. 11, Pages 235: Projective Integration for Hyperbolic Shallow
           Water Moment Equations

    • Authors: Amrita Amrita, Julian Koellermeier
      First page: 235
      Abstract: In free surface flows, shallow water models simplify the flow conditions by assuming a constant velocity profile over the water depth. Recently developed Shallow Water Moment Equations allow for variations of the velocity profile at the expense of a more complex PDE system. The resulting equations can become stiff depending on the friction parameters, which leads to severe time step constraints of standard numerical schemes. In this paper, we apply Projective Integration schemes to stiff Shallow Water Moment Equations to overcome the time step constraints in the stiff regime and accelerate the numerical computations while still achieving high accuracy. In different dam break and smooth wave test cases, we obtain a speedup of up to 55 with respect to standard schemes.
      Citation: Axioms
      PubDate: 2022-05-18
      DOI: 10.3390/axioms11050235
      Issue No: Vol. 11, No. 5 (2022)
       
  • Axioms, Vol. 11, Pages 236: Bounds for the Neuman–Sándor Mean
           in Terms of the Arithmetic and Contra-Harmonic Means

    • Authors: Wen-Hui Li, Peng Miao, Bai-Ni Guo
      First page: 236
      Abstract: In this paper, the authors provide several sharp upper and lower bounds for the Neuman–Sándor mean in terms of the arithmetic and contra-harmonic means, and present some new sharp inequalities involving hyperbolic sine function and hyperbolic cosine function.
      Citation: Axioms
      PubDate: 2022-05-19
      DOI: 10.3390/axioms11050236
      Issue No: Vol. 11, No. 5 (2022)
       
  • Axioms, Vol. 11, Pages 237: Certain Subclasses of Bi-Starlike Function of
           

    • Authors: Alhanouf Alburaikan, Gangadharan Murugusundaramoorthy, Sheza M. El-Deeb
      First page: 237
      Abstract: In the present paper, we introduce new subclasses of bi-starlike and bi-convex functions of complex order associated with Erdély–Kober-type integral operator in the open unit disc and find the estimates of initial coefficients in these classes. Moreover, we obtain Fekete-Szegő inequalities for functions in these classes. Some of the significances of our results are pointed out as corollaries.
      Citation: Axioms
      PubDate: 2022-05-20
      DOI: 10.3390/axioms11050237
      Issue No: Vol. 11, No. 5 (2022)
       
  • Axioms, Vol. 11, Pages 238: An Application of the Super-SBM MAX and
           LTS(A,A,A) Models to Analyze the Business Performance of Hydropower
           Suppliers in Vietnam

    • Authors: Thi Kim Lien Nguyen, Huu Ngoan Nguyen, Van Dan Dinh, Quoc Ngu Nguyen, Van Hung Le
      First page: 238
      Abstract: As Vietnam continues to industrialize and modernize, such economic development and high-tech will require a major electrical energy source to operate the electrical equipment; hence, the hydropower plants are established and growing up to demand. Therefore, the purpose of this study is to evaluate the business performance of Vietnamese hydropower suppliers by integrating the LTS(A,A,A) model of the Additive Holt-winters method in Tableau and a super-slacks-based measure (super-SBM) max model in data envelopment analysis (DEA). The LTS(A,A,A) model is applied to forecast future valuation from 2022 to 2025 based on historical time series from 2012 to 2021. Next, with the actual and predicted data, the researcher uses the super-SBM max model to calculate the business performance of these hydropower suppliers from past to future. The empirical result reveals efficient and inefficient cases to explore which hydropower suppliers can achieve the business performance in their operational process. The position of hydropower suppliers in Vietnam from past to future time is determined particularly based on their scores every year. Further, the empirical result recommends a solution to deal with inefficient cases by deducting the input excesses and raising the output shortages based on the principle of the super-SBM Max model in DEA. The finding results create an overview of the operational process with the continuing variations in each period to equip hydropower suppliers in Vietnam which will determine their future and operational orientation.
      Citation: Axioms
      PubDate: 2022-05-20
      DOI: 10.3390/axioms11050238
      Issue No: Vol. 11, No. 5 (2022)
       
  • Axioms, Vol. 11, Pages 239: Two Invariants for Geometric Mappings

    • Authors: Nenad O. Vesić, Vladislava M. Milenković, Mića S. Stanković
      First page: 239
      Abstract: Two invariants for mappings of affine connection spaces with a special form of deformation tensors are obtained in this paper. We used the methodology of Vesić to obtain the form of these invariants. At the end of this paper, we used these forms to obtain two invariants for third-type almost-geodesic mappings of symmetric affine connection.
      Citation: Axioms
      PubDate: 2022-05-20
      DOI: 10.3390/axioms11050239
      Issue No: Vol. 11, No. 5 (2022)
       
  • Axioms, Vol. 11, Pages 240: Fuzzy Caratheodory’s Theorem and Outer
           ∗-Fuzzy Measure

    • Authors: Radko Mesiar, Chenkuan Li, Abbas Ghaffari, Reza Saadati
      First page: 240
      Abstract: The goal of this paper is to introduce two new concepts ∗-fuzzy premeasure and outer ∗-fuzzy measure, and to further prove some properties, such as Caratheodory’s Theorem, as well as the unique extension of ∗-fuzzy premeasure. This theorem is remarkable for it allows one to construct a ∗-fuzzy measure by first defining it on a small algebra of sets, where its ∗-additivity could be easy to verify, and then this theorem guarantees its extension to a sigma-algebra.
      Citation: Axioms
      PubDate: 2022-05-20
      DOI: 10.3390/axioms11050240
      Issue No: Vol. 11, No. 5 (2022)
       
  • Axioms, Vol. 11, Pages 241: Retrial Queuing-Inventory Systems with Delayed
           Feedback and Instantaneous Damaging of Items

    • Authors: Agassi Melikov, Sevinj Aliyeva, Sajeev S. Nair, B. Krishna Kumar
      First page: 241
      Abstract: This paper studies a Markov model of a queuing-inventory system with primary, retrial, and feedback customers. Primary customers form a Poisson flow, and if an inventory level is positive upon their arrival, they instantly receive the items. If the inventory level is equal to zero upon arrival of a primary customer, then this customer, according to the Bernoulli scheme, either leaves the system or goes into an infinite buffer to repeat their request in the future. The rate of retrial customers is constant, and if the inventory level is zero upon arrival of a retrial customer, then this customer, according to the Bernoulli scheme, either leaves orbit or remains in orbit to repeat its request in the future. According to the Bernoulli scheme, each served primary or retrial customer either leaves the system or feedbacks into orbit to repeat their request. Destructive customers that form a Poisson flow cause damage to items. Unlike primary, retrial, and feedback customers, destructive customers do not require items, since, upon arrival of such customers, the inventory level instantly decreases by one. The system adopted one of two replenishment policies: (s, Q) or (s, S). In both policies, the lead time is a random variable that has an exponential distribution. It is shown that the mathematical model of the system under study was a two-dimensional Markov chain with an infinite state space. Algorithms for calculating the elements of the generating matrices of the constructed chains were developed, and the ergodicity conditions for both policies were found. To calculate the steady-state probabilities, a matrix-geometric method was used. Formulas were found for calculating the main performance measures of the system. The results of the numerical experiments, including the minimization of the total cost, are demonstrated.
      Citation: Axioms
      PubDate: 2022-05-20
      DOI: 10.3390/axioms11050241
      Issue No: Vol. 11, No. 5 (2022)
       
  • Axioms, Vol. 11, Pages 242: The State of the Art of Data Mining Algorithms
           for Predicting the COVID-19 Pandemic

    • Authors: Keila Vasthi Cortés-Martínez, Hugo Estrada-Esquivel, Alicia Martínez-Rebollar, Yasmín Hernández-Pérez, Javier Ortiz-Hernández
      First page: 242
      Abstract: Current computer systems are accumulating huge amounts of information in several application domains. The outbreak of COVID-19 has increased rekindled interest in the use of data mining techniques for the analysis of factors that are related to the emergence of an epidemic. Data mining techniques are being used in the analysis and interpretation of information, which helps in the discovery of patterns, planning of isolation policies, and even predicting the speed of proliferation of contagion in a viral disease such as COVID-19. This research provides a comprehensive study of various data mining algorithms that are used in conjunction with epidemiological prediction models. The document considers that there is an opportunity to improve or develop tools that offer an accurate prognosis in the management of viral diseases through the use of data mining tools, based on a comparative study of 35 research papers.
      Citation: Axioms
      PubDate: 2022-05-23
      DOI: 10.3390/axioms11050242
      Issue No: Vol. 11, No. 5 (2022)
       
  • Axioms, Vol. 11, Pages 243: Some New Bounds for the Inverse Sum Indeg
           Energy of Graphs

    • Authors: Fengwei Li, Qingfang Ye, Hajo Broersma
      First page: 243
      Abstract: Let G be a (molecular) graph with n vertices, and di be the degree of its i-th vertex. Then, the inverse sum indeg matrix of G is the n×n matrix C(G) with entries cij=didjdi+dj, if the i-th and the j-th vertices are adjacent and 0 otherwise. Let μ1≥μ2≥…≥μn be the eigenvalues of C arranged in order. The inverse sum indeg energy of G, εisi(G) can be represented as ∑j=1n μi . In this paper, we establish several novel upper and lower sharp bounds on μ1 and εisi(G) via some other graph parameters, and describe the structures of the extremal graphs.
      Citation: Axioms
      PubDate: 2022-05-23
      DOI: 10.3390/axioms11050243
      Issue No: Vol. 11, No. 5 (2022)
       
 
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