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  • Bayesian Variable Selection with Applications in Health Sciences
    Mathematics (IF 1.747) Pub Date : 2021-01-22
    Gonzalo García-Donato; María Eugenia Castellanos; Alicia Quirós

    In health sciences, identifying the leading causes that govern the behaviour of a response variable is a question of crucial interest. Formally, this can be formulated as a variable selection problem. In this paper, we introduce the basic concepts of the Bayesian approach for variable selection based on model choice, emphasizing the model space prior adoption and the algorithms for sampling from the

    更新日期:2021-01-22
  • Some Properties of the Kilbas-Saigo Function
    Mathematics (IF 1.747) Pub Date : 2021-01-22
    Lotfi Boudabsa; Thomas Simon

    We characterize the complete monotonicity of the Kilbas-Saigo function on the negative half-line. We also provide the exact asymptotics at −∞, and uniform hyperbolic bounds are derived. The same questions are addressed for the classical Le Roy function. The main ingredient for the proof is a probabilistic representation of these functions in terms of the stable subordinator.

    更新日期:2021-01-22
  • Discovery of Resident Behavior Patterns Using Machine Learning Techniques and IoT Paradigm
    Mathematics (IF 1.747) Pub Date : 2021-01-22
    Josimar Reyes-Campos; Giner Alor-Hernández; Isaac Machorro-Cano; José Oscar Olmedo-Aguirre; José Luis Sánchez-Cervantes; Lisbeth Rodríguez-Mazahua

    In recent years, technological paradigms such as Internet of Things (IoT) and machine learning have become very important due to the benefit that their application represents in various areas of knowledge. It is interesting to note that implementing these two technologies promotes more and better automatic control systems that adjust to each user’s particular preferences in the home automation area

    更新日期:2021-01-22
  • On a Retarded Nonlocal Ordinary Differential System with Discrete Diffusion Modeling Life Tables
    Mathematics (IF 1.747) Pub Date : 2021-01-22
    Francisco Morillas; José Valero

    In this paper, we consider a system of ordinary differential equations with non-local discrete diffusion and finite delay and with either a finite or an infinite number of equations. We prove several properties of solutions such as comparison, stability and symmetry. We create a numerical simulation showing that this model can be appropriate to model dynamical life tables in actuarial or demographic

    更新日期:2021-01-22
  • Diffusion–Advection Equations on a Comb: Resetting and Random Search
    Mathematics (IF 1.747) Pub Date : 2021-01-22
    Trifce Sandev; Viktor Domazetoski; Alexander Iomin; Ljupco Kocarev

    This review addresses issues of various drift–diffusion and inhomogeneous advection problems with and without resetting on comblike structures. Both a Brownian diffusion search with drift and an inhomogeneous advection search on the comb structures are analyzed. The analytical results are verified by numerical simulations in terms of coupled Langevin equations for the comb structure. The subordination

    更新日期:2021-01-22
  • Steiner Configurations Ideals: Containment and Colouring
    Mathematics (IF 1.747) Pub Date : 2021-01-21
    Edoardo Ballico; Giuseppe Favacchio; Elena Guardo; Lorenzo Milazzo; Abu Chackalamannil Thomas

    Given a homogeneous ideal I⊆k[x0,…,xn], the Containment problem studies the relation between symbolic and regular powers of I, that is, it asks for which pairs m,r∈N, I(m)⊆Ir holds. In the last years, several conjectures have been posed on this problem, creating an active area of current interests and ongoing investigations. In this paper, we investigated the Stable Harbourne Conjecture and the Stable

    更新日期:2021-01-21
  • On Bonds for Generalized One-Sided Concept Lattices
    Mathematics (IF 1.747) Pub Date : 2021-01-21
    Jozef Pócs; Jana Pócsová

    The generalized one-sided concept lattices represent a generalization of the classical FCA method convenient for a hierarchical analysis of object-attribute models with different types of attributes. The mentioned types of object-attribute models are formalized within the theory as formal contexts of a certain type. The aim of this paper is to investigate some intercontextual relationships represented

    更新日期:2021-01-21
  • A Dependent Lindeberg Central Limit Theorem for Cluster Functionals on Stationary Random Fields
    Mathematics (IF 1.747) Pub Date : 2021-01-21
    José G. Gómez-García; Christophe Chesneau

    In this paper, we provide a central limit theorem for the finite-dimensional marginal distributions of empirical processes (Zn(f))f∈F whose index set F is a family of cluster functionals valued on blocks of values of a stationary random field. The practicality and applicability of the result depend mainly on the usual Lindeberg condition and on a sequence Tn which summarizes the dependence between

    更新日期:2021-01-21
  • The Approximate Analytic Solution of the Time-Fractional Black-Scholes Equation with a European Option Based on the Katugampola Fractional Derivative
    Mathematics (IF 1.747) Pub Date : 2021-01-21
    Sivaporn Ampun; Panumart Sawangtong

    In the finance market, it is well known that the price change of the underlying fractal transmission system can be modeled with the Black-Scholes equation. This article deals with finding the approximate analytic solutions for the time-fractional Black-Scholes equation with the fractional integral boundary condition for a European option pricing problem in the Katugampola fractional derivative sense

    更新日期:2021-01-21
  • Numerical Modelling of Vibration Responses of Helical Gears under Progressive Tooth Wear for Condition Monitoring
    Mathematics (IF 1.747) Pub Date : 2021-01-21
    Xiuquan Sun; Tie Wang; Ruiliang Zhang; Fengshou Gu; Andrew D. Ball

    Gear wear is a common fault that occurs in a gear transmission system that degrades the operating efficiency and may cause other catastrophic failures such as tooth breakage and fatigue. The progressive wear of a helical gear and its influences on vibration responses are rarely investigated due to the combined effects of the complicated lubrication state and the time-varying characteristic. To fill

    更新日期:2021-01-21
  • Invariants of Stable Maps between Closed Orientable Surfaces
    Mathematics (IF 1.747) Pub Date : 2021-01-21
    Catarina Mendes de Jesus S.; Pantaleón D. Romero

    In this paper, we will consider the problem of constructing stable maps between two closed orientable surfaces M and N with a given branch set of curves immersed on N. We will study, from a global point of view, the behavior of its families in different isotopies classes on the space of smooth maps. The main goal is to obtain different relationships between invariants. We will provide a new proof of

    更新日期:2021-01-21
  • Higher-Order Symmetries of a Time-Fractional Anomalous Diffusion Equation
    Mathematics (IF 1.747) Pub Date : 2021-01-21
    Rafail K. Gazizov; Stanislav Yu. Lukashchuk

    Higher-order symmetries are constructed for a linear anomalous diffusion equation with the Riemann–Liouville time-fractional derivative of order α∈(0,1)∪(1,2). It is proved that the equation in question has infinite sequences of nontrivial higher-order symmetries that are generated by two local recursion operators. It is also shown that some of the obtained higher-order symmetries can be rewritten

    更新日期:2021-01-21
  • Interval-Valued Intuitionistic Fuzzy Synthetic Measure (I-VIFSM) Based on Hellwig’s Approach in the Analysis of Survey Data
    Mathematics (IF 1.747) Pub Date : 2021-01-20
    Ewa Roszkowska; Bartłomiej Jefmański

    Several complex phenomena are measured with the use of tools in the form of a questionnaire where the values of criteria are assessed by the respondents using ordinal scales. Therefore, a special method of construction of synthetic measure is needed which takes into account the fact that such measurement scale allows only to determine the relationship between the states of objects: diversity, equality

    更新日期:2021-01-20
  • Analyzing Operational Efficiency in Real Estate Companies: An Application of GM (1,1) and DEA Malmquist Model
    Mathematics (IF 1.747) Pub Date : 2021-01-20
    Chia-Nan Wang; Thi-Ly Nguyen; Thanh-Tuan Dang

    Real estate management and its operation play a crucial role in supporting company operation. Going hand-in-hand with the rapid growth of companies, the real estate portfolio has expanded dramatically, attracting large numbers of domestic and foreign investors. This paper studied the top 12 real estate companies listed on Vietnam’s stock market to develop a method that combines the Grey methodology

    更新日期:2021-01-20
  • A New Algorithm for Computing Disjoint Orthogonal Components in the Three-Way Tucker Model
    Mathematics (IF 1.747) Pub Date : 2021-01-20
    Carlos Martin-Barreiro; John A. Ramirez-Figueroa; Ana B. Nieto-Librero; Víctor Leiva; Ana Martin-Casado; M. Purificación Galindo-Villardón

    One of the main drawbacks of the traditional methods for computing components in the three-way Tucker model is the complex structure of the final loading matrices preventing an easy interpretation of the obtained results. In this paper, we propose a heuristic algorithm for computing disjoint orthogonal components facilitating the analysis of three-way data and the interpretation of results. We observe

    更新日期:2021-01-20
  • Approximating the Density of Random Differential Equations with Weak Nonlinearities via Perturbation Techniques
    Mathematics (IF 1.747) Pub Date : 2021-01-20
    Juan-Carlos Cortés; Elena López-Navarro; José-Vicente Romero; María-Dolores Roselló

    We combine the stochastic perturbation method with the maximum entropy principle to construct approximations of the first probability density function of the steady-state solution of a class of nonlinear oscillators subject to small perturbations in the nonlinear term and driven by a stochastic excitation. The nonlinearity depends both upon position and velocity, and the excitation is given by a stationary

    更新日期:2021-01-20
  • Reliable Efficient Difference Methods for Random Heterogeneous Diffusion Reaction Models with a Finite Degree of Randomness
    Mathematics (IF 1.747) Pub Date : 2021-01-20
    María Consuelo Casabán; Rafael Company; Lucas Jódar

    This paper deals with the search for reliable efficient finite difference methods for the numerical solution of random heterogeneous diffusion reaction models with a finite degree of randomness. Efficiency appeals to the computational challenge in the random framework that requires not only the approximating stochastic process solution but also its expectation and variance. After studying positivity

    更新日期:2021-01-20
  • MooFuzz: Many-Objective Optimization Seed Schedule for Fuzzer
    Mathematics (IF 1.747) Pub Date : 2021-01-20
    Xiaoqi Zhao; Haipeng Qu; Wenjie Lv; Shuo Li; Jianliang Xu

    Coverage-based Greybox Fuzzing (CGF) is a practical and effective solution for finding bugs and vulnerabilities in software. A key challenge of CGF is how to select conducive seeds and allocate accurate energy. To address this problem, we propose a novel many-objective optimization solution, MooFuzz, which can identify different states of the seed pool and continuously gather different information

    更新日期:2021-01-20
  • The Effect of Fractional Time Derivative on Two-Dimension Porous Materials Due to Pulse Heat Flux
    Mathematics (IF 1.747) Pub Date : 2021-01-20
    Tareq Saeed; Ibrahim A. Abbas

    In the present article, the generalized thermoelastic wave model with and without energy dissipation under fractional time derivative is used to study the physical field in porous two-dimensional media. By applying the Fourier-Laplace transforms and eigenvalues scheme, the physical quantities are presented analytically. The surface is shocked by heating (pulsed heat flow problem) and application of

    更新日期:2021-01-20
  • Discrete Optimization: The Case of Generalized BCC Lattice
    Mathematics (IF 1.747) Pub Date : 2021-01-20
    Gergely Kovács; Benedek Nagy; Gergely Stomfai; Neşet Deniz Turgay; Béla Vizvári

    Recently, operations research, especially linear integer-programming, is used in various grids to find optimal paths and, based on that, digital distance. The 4 and higher-dimensional body-centered-cubic grids is the nD (n≥4) equivalent of the 3D body-centered cubic grid, a well-known grid from solid state physics. These grids consist of integer points such that the parity of all coordinates are the

    更新日期:2021-01-20
  • Physiological Balance of the Body: Theory, Algorithms, and Results
    Mathematics (IF 1.747) Pub Date : 2021-01-20
    Irina Alchinova; Mikhail Karganov

    : Aim: To confirm algorithm of determination of risk groups with physiological imbalance in the population exposed to unfavorable anthropogenic influences. Methods: The testing included such functional systems as constitution, myocardial contractility, autonomic regulation of the heart rate, regulation of peripheral circulation, psychomotor regulation, respiratory regulation and metabolism. Monitoring

    更新日期:2021-01-20
  • Modeling Recoveries of US Leading Banks Based on Publicly Disclosed Data
    Mathematics (IF 1.747) Pub Date : 2021-01-19
    Pawel Siarka

    The credit risk management process is a critical element that allows financial institutions to withstand economic downturns. Unlike the methods regarding the probability of default, which have been deeply addressed after the financial crisis in 2008, recovery rate models still need further development. As there are no industry standards, leading banks are modeling recovery rates using internal models

    更新日期:2021-01-19
  • Image Steganalysis via Diverse Filters and Squeeze-and-Excitation Convolutional Neural Network
    Mathematics (IF 1.747) Pub Date : 2021-01-19
    Feng Liu; Xuan Zhou; Xuehu Yan; Yuliang Lu; Shudong Wang

    Steganalysis is a method to detect whether the objects contain secret messages. With the popularity of deep learning, using convolutional neural networks (CNNs), steganalytic schemes have become the chief method of combating steganography in recent years. However, the diversity of filters has not been fully utilized in the current research. This paper constructs a new effective network with diverse

    更新日期:2021-01-19
  • Indistinguishability Operators via Yager t-norms and Their Applications to Swarm Multi-Agent Task Allocation
    Mathematics (IF 1.747) Pub Date : 2021-01-19
    Maria-del-Mar Bibiloni-Femenias; José Guerrero; Juan-José Miñana; Oscar Valero

    In this paper, we propose a family of indistinguishability operators, that we have called Yager Possibilitic Response Functions (YPRFs for short), as an appropriate tool for allocating tasks to a collective of agents. In order to select the best agent to carry out each task, we have used the so-called response threshold method, where each agent decides the next task to perform following a probabilistic

    更新日期:2021-01-19
  • Subordination Properties of Meromorphic Kummer Function Correlated with Hurwitz–Lerch Zeta-Function
    Mathematics (IF 1.747) Pub Date : 2021-01-19
    Firas Ghanim; Khalifa Al-Shaqsi; Maslina Darus; Hiba Fawzi Al-Janaby

    Recently, Special Function Theory (SPFT) and Operator Theory (OPT) have acquired a lot of concern due to their considerable applications in disciplines of pure and applied mathematics. The Hurwitz-Lerch Zeta type functions, as a part of Special Function Theory (SPFT), are significant in developing and providing further new studies. In complex domain, the convolution tool is a salutary technique for

    更新日期:2021-01-19
  • Weak Measurable Optimal Controls for the Problems of Bolza
    Mathematics (IF 1.747) Pub Date : 2021-01-19
    Gerardo Sánchez Licea

    Two sufficiency theorems for parametric and a nonparametric problems of Bolza in optimal control are derived. The dynamics of the problems are nonlinear, the initial and final states are free, and the main results can be applied when nonlinear mixed time-state-control inequality and equality constraints are presented. The deviation between admissible costs and optimal costs around the optimal control

    更新日期:2021-01-19
  • Recognizing Human Races through Machine Learning—A Multi-Network, Multi-Features Study
    Mathematics (IF 1.747) Pub Date : 2021-01-19
    Adrian Sergiu Darabant; Diana Borza; Radu Danescu

    The human face holds a privileged position in multi-disciplinary research as it conveys much information—demographical attributes (age, race, gender, ethnicity), social signals, emotion expression, and so forth. Studies have shown that due to the distribution of ethnicity/race in training datasets, biometric algorithms suffer from “cross race effect”—their performance is better on subjects closer to

    更新日期:2021-01-19
  • On the Complexity of Finding the Maximum Entropy Compatible Quantum State
    Mathematics (IF 1.747) Pub Date : 2021-01-19
    Serena Di Giorgio; Paulo Mateus

    Herein we study the problem of recovering a density operator from a set of compatible marginals, motivated by limitations of physical observations. Given that the set of compatible density operators is not singular, we adopt Jaynes’ principle and wish to characterize a compatible density operator with maximum entropy. We first show that comparing the entropy of compatible density operators is complete

    更新日期:2021-01-19
  • Convergence in Total Variation of Random Sums
    Mathematics (IF 1.747) Pub Date : 2021-01-19
    Luca Pratelli; Pietro Rigo

    Let (Xn) be a sequence of real random variables, (Tn) a sequence of random indices, and (τn) a sequence of constants such that τn→∞. The asymptotic behavior of Ln=(1/τn)∑i=1TnXi, as n→∞, is investigated when (Xn) is exchangeable and independent of (Tn). We give conditions for Mn=τn(Ln−L)⟶M in distribution, where L and M are suitable random variables. Moreover, when (Xn) is i.i.d., we find constants

    更新日期:2021-01-19
  • Design and Analysis of a Cluster-Based Intelligent Hybrid Recommendation System for E-Learning Applications
    Mathematics (IF 1.747) Pub Date : 2021-01-19
    S. Bhaskaran; Raja Marappan; B. Santhi

    Recently, different recommendation techniques in e-learning have been designed that are helpful to both the learners and the educators in a wide variety of e-learning systems. Customized learning, which requires e-learning systems designed based on educational experience that suit the interests, goals, abilities, and willingness of both the learners and the educators, is required in some situations

    更新日期:2021-01-19
  • Acknowledgment to Reviewers of Mathematics in 2020
    Mathematics (IF 1.747) Pub Date : 2021-01-19
    Mathematics Editorial Office

    Note: In lieu of an abstract, this is an excerpt from the first page. Peer review is the driving force of journal development, and reviewers are gatekeepers who ensure that Mathematics maintains its standards for the high quality of its published papers. [...]

    更新日期:2021-01-19
  • Some Applications of the Wright Function in Continuum Physics: A Survey
    Mathematics (IF 1.747) Pub Date : 2021-01-19
    Yuriy Povstenko

    The Wright function is a generalization of the exponential function and the Bessel functions. Integral relations between the Mittag–Leffler functions and the Wright function are presented. The applications of the Wright function and the Mainardi function to description of diffusion, heat conduction, thermal and diffusive stresses, and nonlocal elasticity in the framework of fractional calculus are

    更新日期:2021-01-19
  • Recovering Density and Speed of Sound Coefficients in the 2D Hyperbolic System of Acoustic Equations of the First Order by a Finite Number of Observations
    Mathematics (IF 1.747) Pub Date : 2021-01-19
    Dmitriy Klyuchinskiy; Nikita Novikov; Maxim Shishlenin

    We consider the coefficient inverse problem for the first-order hyperbolic system, which describes the propagation of the 2D acoustic waves in a heterogeneous medium. We recover both the denstity of the medium and the speed of sound by using a finite number of data measurements. We use the second-order MUSCL-Hancock scheme to solve the direct and adjoint problems, and apply optimization scheme to the

    更新日期:2021-01-19
  • Data Envelopment Analysis Approach to Energy-Saving Projects Selection in an Energy Service Company
    Mathematics (IF 1.747) Pub Date : 2021-01-19
    Gabriel Villa; Sebastián Lozano; Sandra Redondo

    Project selection is a common problem for many companies. Specifically, it consists in identifying which projects should be selected with regard to their economic efficiency, i.e., the projects that maximise the profit they bring in while minimising the cost of the resources consumed. In this paper, we have focused our interest on energy service companies because of the importance of a convenient selection

    更新日期:2021-01-19
  • Statistical Arbitrage in Emerging Markets: A Global Test of Efficiency
    Mathematics (IF 1.747) Pub Date : 2021-01-18
    Karen Balladares; José Pedro Ramos-Requena; Juan Evangelista Trinidad-Segovia; Miguel Angel Sánchez-Granero

    In this paper, we use a statistical arbitrage method in different developed and emerging countries to show that the profitability of the strategy is based on the degree of market efficiency. We will show that our strategy is more profitable in emerging ones and in periods with greater uncertainty. Our method consists of a Pairs Trading strategy based on the concept of mean reversion by selecting pair

    更新日期:2021-01-18
  • Using Artificial Neural Network with Prey Predator Algorithm for Prediction of the COVID-19: The Case of Brazil and Mexico
    Mathematics (IF 1.747) Pub Date : 2021-01-18
    Nawaf N. Hamadneh; Muhammad Tahir; Waqar A. Khan

    The spread of the COVID-19 epidemic worldwide has led to investigations in various aspects, including the estimation of expected cases. As it helps in identifying the need to deal with cases caused by the pandemic. In this study, we have used artificial neural networks (ANNs) to predict the number of cases of COVID-19 in Brazil and Mexico in the upcoming days. Prey predator algorithm (PPA), as a type

    更新日期:2021-01-18
  • A Note on the Paired-Domination Subdivision Number of Trees
    Mathematics (IF 1.747) Pub Date : 2021-01-18
    Xiaoli Qiang; Saeed Kosari; Zehui Shao; Seyed Mahmoud Sheikholeslami; Mustapha Chellali; Hossein Karami

    For a graph G with no isolated vertex, let γpr(G) and sdγpr(G) denote the paired-domination and paired-domination subdivision numbers, respectively. In this note, we show that if T is a tree of order n≥4 different from a healthy spider (subdivided star), then sdγpr(T)≤min{γpr(T)2+1,n2}, improving the (n−1)-upper bound that was recently proven.

    更新日期:2021-01-18
  • Coverability of Graphs by Parity Regular Subgraphs
    Mathematics (IF 1.747) Pub Date : 2021-01-18
    Mirko Petruševski; Riste Škrekovski

    A graph is even (resp. odd) if all its vertex degrees are even (resp. odd). We consider edge coverings by prescribed number of even and/or odd subgraphs. In view of the 8-Flow Theorem, a graph admits a covering by three even subgraphs if and only if it is bridgeless. Coverability by three odd subgraphs has been characterized recently [ Petruševski, M.; Škrekovski, R. Coverability of graph by three

    更新日期:2021-01-18
  • Mathematical Calculation of Stray Losses in Transformer Tanks with a Stainless Steel Insert
    Mathematics (IF 1.747) Pub Date : 2021-01-18
    Serguei Maximov; Manuel A. Corona-Sánchez; Juan C. Olivares-Galvan; Enrique Melgoza-Vazquez; Rafael Escarela-Perez; Victor M. Jimenez-Mondragon

    At present it is claimed that all electrical energy systems operate with high values of efficiency and reliability. In electric power systems (EPS), electrical power and distribution transformers are responsible for transferring the electrical energy from power stations up to the load centers. Consequently, it is mandatory to design transformers that possess the highest efficiency and reliability possible

    更新日期:2021-01-18
  • Alikhanov Legendre—Galerkin Spectral Method for the Coupled Nonlinear Time-Space Fractional Ginzburg–Landau Complex System
    Mathematics (IF 1.747) Pub Date : 2021-01-18
    Mahmoud A. Zaky; Ahmed S. Hendy; Rob H. De Staelen

    A finite difference/Galerkin spectral discretization for the temporal and spatial fractional coupled Ginzburg–Landau system is proposed and analyzed. The Alikhanov L2-1σ difference formula is utilized to discretize the time Caputo fractional derivative, while the Legendre-Galerkin spectral approximation is used to approximate the Riesz spatial fractional operator. The scheme is shown efficiently applicable

    更新日期:2021-01-18
  • Enhancing Portfolio Performance and VIX Futures Trading Timing with Markov-Switching GARCH Models
    Mathematics (IF 1.747) Pub Date : 2021-01-18
    Oscar V. De la Torre-Torres; Francisco Venegas-Martínez; Mª Isabel Martínez-Torre-Enciso

    In the present paper, we test the use of Markov-Switching (MS) models with time-fixed or Generalized Autoregressive Conditional Heteroskedasticity (GARCH) variances. This, to enhance the performance of a U.S. dollar-based portfolio that invest in the S&P 500 (SP500) stock index, the 3-month U.S. Treasury-bill (T-BILL) or the 1-month volatility index (VIX) futures. For the investment algorithm, we propose

    更新日期:2021-01-18
  • Impact of Renewable Energy Sources into Multi Area Multi-Source Load Frequency Control of Interrelated Power System
    Mathematics (IF 1.747) Pub Date : 2021-01-18
    Krishan Arora; Ashok Kumar; Vikram Kumar Kamboj; Deepak Prashar; Bhanu Shrestha; Gyanendra Prasad Joshi

    There is an increasing concentration in the influences of nonconventional power sources on power system process and management, as the application of these sources upsurges worldwide. Renewable energy technologies are one of the best technologies for generating electrical power with zero fuel cost, a clean environment, and are available almost throughout the year. Some of the widespread renewable energy

    更新日期:2021-01-18
  • Third Grade Students’ Use of Relational Thinking
    Mathematics (IF 1.747) Pub Date : 2021-01-18
    Marta Molina; Encarnación Castro

    Current mathematics curricula have as one of their fundamental objectives the development of number sense. This is understood as a set of skills. Some of them have an algebraic nature such as acquiring an abstract understanding of relations between numbers, developing awareness of properties and of the structure of the decimal number system and using it in a strategic manner. In this framework, the

    更新日期:2021-01-18
  • Enhancing Accuracy of Runge–Kutta-Type Collocation Methods for Solving ODEs
    Mathematics (IF 1.747) Pub Date : 2021-01-16
    Janez Urevc; Miroslav Halilovič

    In this paper, a new class of Runge–Kutta-type collocation methods for the numerical integration of ordinary differential equations (ODEs) is presented. Its derivation is based on the integral form of the differential equation. The approach enables enhancing the accuracy of the established collocation Runge–Kutta methods while retaining the same number of stages. We demonstrate that, with the proposed

    更新日期:2021-01-18
  • Capital Allocation Rules and the No-Undercut Property
    Mathematics (IF 1.747) Pub Date : 2021-01-16
    Gabriele Canna; Francesca Centrone; Emanuela Rosazza Gianin

    This paper makes the point on a well known property of capital allocation rules, namely the one called no-undercut. Its desirability in capital allocation stems from some stability game theoretical features that are related to the notion of core, both for finite and infinite games. We review these aspects, by relating them to the properties of the risk measures that are involved in capital allocation

    更新日期:2021-01-18
  • Estimation of Synchronization Errors between Master and Slave Chaotic Systems with Matched/Mismatched Disturbances and Input Uncertainty
    Mathematics (IF 1.747) Pub Date : 2021-01-17
    Chih-Hsueh Lin; Guo-Hsin Hu; Jun-Juh Yan

    This study is concerned with robust synchronization for master–slave chaotic systems with matched/mismatched disturbances and uncertainty in the control input. A robust sliding mode control (SMC) is presented to achieve chaos synchronization even under the influence of matched/mismatched disturbances and uncertainty of inputs. A proportional-integral (PI) switching surface is introduced to make the

    更新日期:2021-01-18
  • Boolean Functions and Permanents of Sylvester Hadamard Matrices
    Mathematics (IF 1.747) Pub Date : 2021-01-17
    José Andrés Armario

    One of the fastest known general techniques for computing permanents is Ryser’s formula. On this note, we show that this formula over Sylvester Hadamard matrices of order 2m, Hm, can be carried out by enumerating m-variable Boolean functions with an arbitrary Walsh spectrum. As a consequence, the quotient per(Hm)/22m might be a measure of the “density” of m-variable Boolean functions with high nonlinearity

    更新日期:2021-01-18
  • On the Reciprocal Sums of Products of Two Generalized Bi-Periodic Fibonacci Numbers
    Mathematics (IF 1.747) Pub Date : 2021-01-17
    Younseok Choo

    This paper concerns the properties of the generalized bi-periodic Fibonacci numbers {Gn} generated from the recurrence relation: Gn=aGn−1+Gn−2 (n is even) or Gn=bGn−1+Gn−2 (n is odd). We derive general identities for the reciprocal sums of products of two generalized bi-periodic Fibonacci numbers. More precisely, we obtain formulas for the integer parts of the numbers ∑k=n∞(a/b)ξ(k+1)GkGk+m−1,m=0,2

    更新日期:2021-01-18
  • Proposing a New Theorem to Determine If an Algebraic Polynomial Is Nonnegative in an Interval
    Mathematics (IF 1.747) Pub Date : 2021-01-15
    Ke-Pao Lin; Yi-Fan Wang; Ruo-Yu Wang; Andrew Yang

    We face the problem to determine whether an algebraic polynomial is nonnegative in an interval the Yau Number Theoretic Conjecture and Yau Geometric Conjecture is proved. In this paper, we propose a new theorem to determine if an algebraic polynomial is nonnegative in an interval. It improves Wang-Yau Lemma for wider applications in light of Sturm’s Theorem. Many polynomials can use the new theorem

    更新日期:2021-01-15
  • Dynamic Graph Learning: A Structure-Driven Approach
    Mathematics (IF 1.747) Pub Date : 2021-01-15
    Bo Jiang; Yuming Huang; Ashkan Panahi; Yiyi Yu; Hamid Krim; Spencer L. Smith

    The purpose of this paper is to infer a dynamic graph as a global (collective) model of time-varying measurements at a set of network nodes. This model captures both pairwise as well as higher order interactions (i.e., more than two nodes) among the nodes. The motivation of this work lies in the search for a connectome model which properly captures brain functionality across all regions of the brain

    更新日期:2021-01-15
  • Simplicial-Map Neural Networks Robustto Adversarial Examples
    Mathematics (IF 1.747) Pub Date : 2021-01-15
    Eduardo Paluzo-Hidalgo; Rocio Gonzalez-Diaz; Miguel A. Gutiérrez-Naranjo; Jónathan Heras

    Broadly speaking, an adversarial example against a classification model occurs when a small perturbation on an input data point produces a change on the output label assigned by the model. Such adversarial examples represent a weakness for the safety of neural network applications, and many different solutions have been proposed for minimizing their effects. In this paper, we propose a new approach

    更新日期:2021-01-15
  • An Over and Underdispersed Biparametric Extension of the Waring Distribution
    Mathematics (IF 1.747) Pub Date : 2021-01-15
    Valentina Cueva-López; María José Olmo-Jiménez; José Rodríguez-Avi

    A new discrete distribution for count data called extended biparametric Waring (EBW) distribution is developed. Its name is related to the fact that, in a specific configuration of its parameters, it can be seen as a biparametric version of the univariate generalized Waring (UGW) distribution, a well-known model for the variance decomposition into three components: randomness, liability and proneness

    更新日期:2021-01-15
  • A Comparative Study of Swarm Intelligence Algorithms for UCAV Path-Planning Problems
    Mathematics (IF 1.747) Pub Date : 2021-01-15
    Haoran Zhu; Yunhe Wang; Zhiqiang Ma; Xiangtao Li

    Path-planning for uninhabited combat air vehicles (UCAV) is a typically complicated global optimization problem. It seeks a superior flight path in a complex battlefield environment, taking into various constraints. Many swarm intelligence (SI) algorithms have recently gained remarkable attention due to their capability to address complex optimization problems. However, different SI algorithms present

    更新日期:2021-01-15
  • A Novel IGC Scheme for RHV with the Capabilities of Online Aerodynamic Coefficient Estimation and Trajectory Generation
    Mathematics (IF 1.747) Pub Date : 2021-01-15
    Xueyun Wang; Yifan Li; Jingjuan Zhang

    A novel integrated guidance and control (IGC) scheme for a Re-entry Hypersonic Vehicle (RHV) is proposed with the capabilities of online aerodynamic coefficient estimation based on an Unscented Kalman Filter and online trajectory generation based on the Gaussian pseudospectral method. A linear quadratic regulator is adopted for trajectory tracking guidance and a second-layer sliding mode controller

    更新日期:2021-01-15
  • Four-Fold Formal Concept Analysis Based on Complete Idempotent Semifields
    Mathematics (IF 1.747) Pub Date : 2021-01-15
    Francisco José Valverde-Albacete; Carmen Peláez-Moreno

    Formal Concept Analysis (FCA) is a well-known supervised boolean data-mining technique rooted in Lattice and Order Theory, that has several extensions to, e.g., fuzzy and idempotent semirings. At the heart of FCA lies a Galois connection between two powersets. In this paper we extend the FCA formalism to include all four Galois connections between four different semivectors spaces over idempotent semifields

    更新日期:2021-01-15
  • Resource Allocation Effect of Green Credit Policy: Based on DID Model
    Mathematics (IF 1.747) Pub Date : 2021-01-14
    Guangyou Zhou; Chen Liu; Sumei Luo

    From the perspective of the policy impact effect, this paper takes green enterprises as the treatment group and polluters as the control group. Firstly, the double difference method (DID) was adopted to study the effect of green credit policy on enterprises from two aspects, namely the amount of loans obtained by enterprises and the financing cost. The study found that in terms of loan volume, the

    更新日期:2021-01-14
  • Quadrature Integration Techniques for Random Hyperbolic PDE Problems
    Mathematics (IF 1.747) Pub Date : 2021-01-14
    Rafael Company; Vera N. Egorova; Lucas Jódar

    In this paper, we consider random hyperbolic partial differential equation (PDE) problems following the mean square approach and Laplace transform technique. Randomness requires not only the computation of the approximating stochastic processes, but also its statistical moments. Hence, appropriate numerical methods should allow for the efficient computation of the expectation and variance. Here, we

    更新日期:2021-01-14
  • On Jungck–Branciari–Wardowski Type Fixed Point Results
    Mathematics (IF 1.747) Pub Date : 2021-01-14
    Biljana Carić; Tatjana Došenović; Reny George; Zoran D. Mitrović; Stojan Radenović

    The terms of F−integral contraction as well as (ϖ,ζ˜,F,i)−integral contraction are introduced. Fixed point and common fixed point theorems are established. For the mapping F we use only the supposition that it is strictly increasing. As a consequence of the main theorems we obtain Jungck–Wardowski, Branciari–Wardowski and Jungck–Branciari type results. Consequently, the results presented in the article

    更新日期:2021-01-14
  • Mathematical Modeling as a Catalyst for Equitable Mathematics Instruction: Preparing Teachers and Young Learners with 21st Century Skills
    Mathematics (IF 1.747) Pub Date : 2021-01-14
    Jennifer Suh; Kathleen Matson; Padmanabhan Seshaiyer; Spencer Jamieson; Holly Tate

    This case study focuses on a team of teachers and students in a Lesson Study, focused on using mathematical modeling (MM) to make significant decisions to design and plan for a sustainable edible garden in their community. We examined (a) how teachers develop students’ capacity to engage in mathematical modeling, while attending to equitable teaching practices; and (b) how teachers’ view of teaching

    更新日期:2021-01-14
  • Transferable Utility Cooperative Differential Games with Continuous Updating Using Pontryagin Maximum Principle
    Mathematics (IF 1.747) Pub Date : 2021-01-14
    Jiangjing Zhou; Anna Tur; Ovanes Petrosian; Hongwei Gao

    We consider a class of cooperative differential games with continuous updating making use of the Pontryagin maximum principle. It is assumed that at each moment, players have or use information about the game structure defined in a closed time interval of a fixed duration. Over time, information about the game structure will be updated. The subject of the current paper is to construct players’ cooperative

    更新日期:2021-01-14
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