Mathematical Problems in Engineering

https://www.hindawi.com/journals/mpe/

List of Papers (Total 806)

Torsional and longitudinal vibration of suspension bridge subject to aerodynamic forces

In this paper we consider a dynamic model of suspension bridge governed by a pair of coupled partial differential equations which describe both torsional and longitudinal vibration of the road bed. The vertical and torsional motions are coupled through a nonlinear operation with the nonlinearity arising from loss of tension in the vertical cables supporting the decks. We study...

A problem related to the hall effect in a semiconductor with an electrode of an arbitrary shape

A problem on electric current in a semiconductor film from an electrode of an arbitrary shape is studied in the presence of a magnetic field. This situation describes the Hall effect, which indicates the deflection of electric, current from electric field in a semiconductor. From mathematical standpoint we consider the skew derivative problem for harmonic functions in the...

Passivation and control of partially known SISO nonlinear systems via dynamic neural networks

In this paper, an adaptive technique is suggested to provide the passivity property for a class of partially known SISO nonlinear systems. A simple Dynamic Neural Network (DNN), containing only two neurons and without any hidden-layers, is used to identify the unknown nonlinear system. By means of a Lyapunov-like analysis the new learning law for this DNN, guarantying both...

Peristaltic transport of an Oldroyd-B fluid in a planar channel

The effects of an Oldroyd-B fluid on the peristaltic mechanism are examined under the long wavelength assumption. Analytical expressions for the stream function, the axial velocity, and the pressure rise per wavelength are obtained up to the second order in the dimensionless wave number. The effects of the various parameters of interest on the flow are shown and discussed.

Realization problem for positive linear systems with time delay

The realization problem for positive single-input single-output discrete-time systems with one time delay is formulated and solved. Necessary and sufficient conditions for the solvability of the realization problem are established. A procedure for computation of a minimal positive realization of a proper rational function is presented and illustrated by an example.

Modifying Olympics Medal Table via a Stochastic Multicriteria Acceptability Analysis

This paper addresses the issue of developing a widely accepted Olympics ranking scheme based upon the Olympic Game medal table published by the International Olympic Committee, since the existing lexicographic ranking and sum ranking systems are both criticized as biases. More specifically, the lexicographic ranking system is deemed as overvaluing gold medals, while the sum...

A New Calibration Method for the Real-Time Calculation of Dynamic Safety Following Distance under Railway Moving Block System

Only the actual following distance that is a little greater than the optimum safety following distance at any time can make the following train move in safety and efficiency. For this purpose, a new calibration method is studied for the real-time calculation of the dynamically optimum safety following distance. To cope with the complex situations of train following operation, the...

Sparsity Based Locality-Sensitive Discriminative Dictionary Learning for Video Semantic Analysis

Dictionary learning (DL) and sparse representation (SR) based classifiers have greatly impacted the classification performance and have had good recognition rate on image data. In video semantic analysis (VSA), the local structure of video data contains more vital discriminative information needed for classification. However, this has not been fully exploited by the current DL...

Research on Local Government Governance and Enterprise Social Responsibility Behaviors under the Perspective of Cournot Duopoly Competition: Analyzing Taxi Companies and Online Car-Hailing Service Companies

Clarifying the rational choice strategy of local governments and enterprises is crucial for promoting control on the failure of taxis and online car-hailing service companies to fulfill their social responsibilities. The local government can reduce the negative externalities and irresponsibility of such companies by improving the regulatory system; thus, it is important to build...

Prediction of Surface Roughness and Optimization of Cutting Parameters of Stainless Steel Turning Based on RSM

The turning test of stainless steel was carried out by using the central composite surface design of response surface method (RSM) and Taguchi design method of central combination design. The influence of cutting parameters (cutting speed, feed rate, and cutting depth) on the surface roughness was analyzed. The surface roughness prediction model was established based on the...

A Grey-Fuzzy Multiobjective Model for Supplier Selection and Production-Distribution Planning Considering Consumer Safety

Most of the recent product recall incidents indicate that effective management of suppliers and production-distribution planning may play a vital role in increasing product safety. This study explores the opportunities to increase the product safety by analyzing the performance of suppliers and production-distribution system. More precisely, this research analyzes the impact of...

Gray Relational Optimization of the Surface Performance of Splines Formed by Cold Roll-Beating

Surface roughness, residual stress, and work hardening are the key parameters characterizing the mechanical properties of a spline surface after undergoing cold roll-beating. A comprehensive optimization of the mechanical properties of such surfaces has not been previously reported. To improve the performance of the spline surface, gray theory is used to study the relationships...

Supply Chain Decision-Making Based on Warehouse Receipt Pledge and Risk Consideration under Twice Ordering Mode

This paper studies supply chain decisions making between the retailer, supplier, and bank based on warehouse receipt pledge and risk consideration under twice ordering mode. The decentralized supply chain and centralized supply chain are divided by whether the supplier provides repurchase guarantees and whether the retailer offers revenue sharing. We develop a Stackelberg game...

Strain Analysis of the Nuozhadu High Rockfill Dam during Initial Impoundment

The safety of rockfill dams during initial impoundment has always been an issue of interest for regulatory agencies. Specifically, it is necessary to identify potential tensile strain zones and shear strain concentration zones in which cracks may form. In this paper, a meshless smoothing method is proposed to construct the strain field of a prototype dam based on monitoring...

A New Control Method for Second-Order Multiple Models Control System Based on Global Sliding Mode

This paper proposed a finite time convergence global sliding mode control scheme for the second-order multiple models control system. Firstly, the global sliding surface without reaching law for a single model control system is designed and the tracking error finite time convergence and global stability are proved. Secondly, we generalize the above scheme to the second-order...

Topology Optimization Analysis of Separation Mechanism for the Rice Trans-Planter

A mechanical topology regeneration design method based on the basic chain was presented which was reducing invalid topology design workload and improving optimization design efficiency. And it is used for configuration topology research of planetary separation mechanism of rice transplanting machine to verify its feasibility and effectiveness, which mainly consists of crank...

Robust Local Stabilization of Discrete-Time Systems with Time-Varying State Delay and Saturating Actuators

The robust local stabilization of uncertain discrete-time systems with time-varying state delayed and subject to saturating actuators is investigated in this work. A convex optimization method is proposed to compute robust state feedback control law such that the uncertain closed-loop is locally asymptotically stable if the initial condition belongs to an estimate of the region...

A modeling and control framework for operating large-scale electric power systems under present and newly evolving competitive industry structures

This paper introduces a systematic, structure-based modeling framework for analysis and control of electric power systems for processes evolving over the mid-term and long-term time horizons. Much simpler models than the detailed dynamics specifically for control design at different hierarchical levels are obtained by applying both temporal and spatial separation. These simple...

A 2D finite element procedure for magnetic field analysis taking into account a vector Preisach model

The main purpose of this paper is to incorporate a refined hysteresis model, viz. a vector Preisach model, in 2D magnetic field computations. To this end the governing Maxwell equations are rewritten in a suitable way, which allows to take into account the proper magnetic material parameters and, moreover, to pass to a variational formulation. The variational problem is solved...

Vertical flow of a multiphase mixture in a channel

The flow of a multiphase mixture consisting of a viscous fluid and solid particles between two vertical plates is studied. The theory of interacting continua or mixture theory is used. Constitutive relations for the stress tensor of the granular materials and the interaction force are presented and discussed. The flow of interest is an ideal one where we assume the flow to be...

A hybrid domain analysis for systems with delays in state and control

The solution of time-delay systems is obtained by using a hybrid function. The properties of the hybrid functions consisting of block-pulse functions and Chebyshev polynomials are presented. The method is based upon expanding various time functions in the system as their truncated hybrid functions. The operational matrix of delay is introduced. The operational matrices of...

Determination of an unknown parameter in a semi-linear parabolic equation

Some finite difference approximations are developed for an inverse problem of determining an unknown parameter p(t) which is a coefficient of the solution u in a semi-linear parabolic partial differential equation subject to a boundary integral overspecification. The accuracy and efficiency of the procedures are discussed. Some computational results using the newly proposed...

Analytical investigations of the Sumudu transform and applications to integral production equations

The Sumudu transform, whose fundamental properties are presented in this paper, is little known and not widely used. However, being the theoretical dual to the Laplace transform, the Sumudu transform rivals it in problem solving. Having scale and unit-preserving properties, the Sumudu transform may be used to solve problems without resorting to a new frequency domain. Here, we...

Volterra equations with fractional stochastic integrals

Some fractional stochastic systems of integral equations are studied. The fractional stochastic Skorohod integrals are also studied. The existence and uniquness of the considered stochastic fractional systems are established. An application of the fractional Black-Scholes is considered.

Solution of nonlinear Fredholm-Hammerstein integral equations by using semiorthogonal spline wavelets

Compactly supported linear semiorthogonal B-spline wavelets together with their dual wavelets are developed to approximate the solutions of nonlinear Fredholm-Hammerstein integral equations. Properties of these wavelets are first presented; these properties are then utilized to reduce the computation of integral equations to some algebraic equations. The method is computationally...