In this paper, a nonlinear parameter-excited model of spinning pipes conveying fluid is proposed by considering the spinning speed and flow velocity are perturbed periodically, and the stability and nonlinear parametric vibrations of such system are studied analytically and numerically. With taking the viscoelastic material and geometrical nonlinearity due to extensible pipe axis into account, the

This article proposes chance-constrained formulations for the calibration of computational models given data subject to uncertainty. The uncertainty might be caused by a poor metrology system, measurement noise, model-form uncertainty or by the inability to directly measure the inputs and/or outputs of the model. The formulations developed, called Forward Maximum Likelihood and Inverse Maximum Likelihood

In this paper, a cooperative optimization strategy is proposed for velocity planning and energy management of intelligent connected plug-in hybrid electric vehicles. Based on the established vehicle model, a mathematical analytical method is investigated to convert the driving cycles from the original time based profiles to the driving distance based speed values. Then, the iterative dynamic programming

We adopt an operatorial method, based on truncated bosons, to describe the dynamics of populations in a closed region with a non trivial topology. The main operator that includes the various mechanisms and interactions between the populations is the Hamiltonian, constructed with the density and transport operators. The whole evolution is derived from the Schrödinger equation, and the densities of the

Together with emerging infectious diseases, dengue fever continues to ravage tropical and subtropical countries amidst weak health systems. Vertical and sexual transmission have been shown to exhibit synergism in the endemic maintenance during inter-epidemics. This work presents a SISUV model modulating horizontal transmission, also vertical and sexual transmission in mosquitoes. Mendel’s law applied

An integrated modeling approach has been developed to better understand the relative impacts of different expiratory and environmental factors on airborne pathogen transport and transmission, motivated by the recent COVID-19 pandemic. Computational fluid dynamics (CFD) modeling was used to simulate spatial-temporal aerosol concentrations and quantified risks of exposure as a function of separation

A novel fourth-order linear moment (L-moment) reliability method considering linear correlated (L-correlated) random variables is developed to improve accuracy and applicability on the premise of ensuring FORM's computational efficiency. For accomplishing this task, a novel normal transformation's implementation based on L-moments and L-correlations is established, and the complete monotonic expressions

A mathematical model for the simulation of the dynamics of spherical vapor-air bubbles and its numerical implementation is presented. Heat and mass transfer and phase transition in terms of evaporation and condensation as well as air absorption and desorption are considered. Flow variables are discretized by a mixed finite volume / finite difference scheme and solved either by a Crank-Nicolson or Runge-Kutta

Vertical vibration of a rigid disk embedded in a multi-layered poroelastic medium is considered in this paper, for the first time. The whole medium is underlying a liquid layer with finite depth to evaluate the submarine structures. Extended reflection and transmission matrix are introduced for layered porous media. The governing differential equations are simplified by virtue of Fourier and Hankel

We investigate the onset of temporal dynamics of a fluidic oscillator (FO) in the laminar regime at very low Reynolds number (Re=Uhi/ν, where U and hi are the velocity and channel height at inlet, and ν is the kinematic viscosity of the fluid). Both two- and spanwise-periodic-three-dimensional simulations are performed using high-order spectral element methods to characterise the flow inside the FO

In their article, N. A. Kudryashov, M. A. Chmykhov, M. Vigdorowitsch, “Analytical features of the SIR model and their applications to COVID-19”, Applied Mathematical Modelling 90 (2021) 466–473, aimed to establish the relationships among S, I and R populations, as well as to suggest a form for the exact solution of the SIR model. One of the equations given there is not correct, which leads to an error

This paper considers the problem of low-tubal-rank tensor completion from incomplete one-bit observations. Our work is inspired by the recently proposed invertible linear transforms based tensor-tensor product and transformed tensor singular value decomposition (t-SVD). Under this framework, a tensor nuclear norm constrained maximum log-likelihood estimation model is proposed, which is convex and efficiently

In this paper, the dynamic model of an eccentric rotating carbon fiber reinforced polymer (CFRP) laminated cylindrical shell based on the first-order shear deformation theory is established for the first time. The buckling and free vibration analyses of the eccentric rotating CFRP laminated cylindrical shell under the axial excitation are presented. Taking into account the influences of Coriolis force

Accurately estimating thermoelastic damping (TED) is of significance for the design of micro/nano-resonators with high quality factor. This work aims at providing new investigation of TED with considering the non-Fourier heat conduction (NFHC) effect and the size-dependent effects in the thermal and mechanical fields. Analytical models of TED in rectangular and circular micro/nanoplate resonators are

Viscoelasticity is an inherent property of the biological tissue and is often used as a diagnosis parameter in characterizing cancer. Recently, it has been found that fractional calculus agrees well with experimental results when describing the viscoelastic materials. In this study, the fractional linear thermo-viscoelastic theory is developed with considering the fractional relaxation effect of dual

Perishability of agri-food products impacts the economic, environmental, and social aspects of agri-food supply chains (AFSCs). Product perishability is, usually, considered in tactical and operational decisions, but not in strategic ones, such as the design of the AFSC. The contribution of this paper is that it investigates the impact of product perishability on an AFSC design. To do so, first, a

Solutions to nonlinear free vibration analysis of an arbitrarily laminated thin rectangular plate subjected to thermo-piezoelectric load is investigated. The governing equation of motion is based on von Kármán’s deflection of thin plates to capture the effects of moderate geometric nonlinearity. Induced strain actuation assumption is confined to a linear model for applied low electric fields and varying

COVID-19 pandemic has impacted people all across the world. As a result, there has been a collective effort to monitor, predict, and control the spread of this disease. Among this effort is the development of mathematical models that could capture accurately the available data and simulate closely the futuristic scenarios. In this paper, a fractional-order memory-dependent model for simulating the

Although schistosomiasis containment campaigns have recorded substantial success in most developed countries, sub-Saharan Africa still suffers greatly under the burden of the disease. A basic mathematical model to assess the impact of concomitant immunity in humans and environmental transmission of schistosomiasis disease progression is formulated. Mathematical analysis is carried out to establish

In practice, manufacturers who offer base and extended warranty should make simultaneous decisions on product pricing, spare part pricing for out-of-warranty products, base and extended warranty policy, and spare part inventory management. Previous studies neither considered the influence of out-of-warranty products as one of the main sources of manufacturers’ profit nor optimized these decisions in

In this study, the method of fundamental solutions (MFS), which is a boundary-type meshfree method, is applied for solving two-dimensional stationary anisotropic thermoelastic problems. Because of the semi-analytic nature of the MFS, very accurate solutions can be obtained by this method. The solution of the problem is decomposed into homogeneous and particular solutions. The homogeneous solution is

The purpose of this work is to analyze the dynamic response of transversely isotropic saturated media under circular moving loads, in which the vertical and tangential loads can be simultaneously considered. Based on Biot's poroelastic theory and the Galilean transformation, the partial differential governing equations in a fixed Cartesian coordinate system are converted into those in a moving coordinate

A four-way enhanced numerical manifold method (NMM) is proposed in order to simulate crack propagation in rock media and progressive failure of jointed rock slopes. Specifically, the original NMM is improved in the following four aspects: (1) An “enriched local approximation” is employed to characterize singularity and discontinuity of the displacement/stress fields near the crack tip. (2) A “modified

According to the Hertz's contact theory (HCT) and considering the strain hardening of materials, an effective calculation method is proposed for solving the elasto-plastic contact pressure and the contact patch size under arbitrary smooth and continuous contact conditions. Firstly, it is assumed that the outer and inner edges of the contact patch are elastic and elasto-plastic contact zones, respectively

We define a new two-sided class F of distributions and a generalized class by compounding this class with a baseline distribution G. The new model is called the general two-sided FG class. Some of its properties are provided. The proposed model is specialized taking the Weibull and exponential for F and G, respectively. For a new specialized distribution, we obtain the survival, quantiles and hazard

In the past decade, relevance vector machines have gained the attention of many researchers, and this machine learning technique is a Bayesian sparse kernel method, both for classification and regression problems. In general, the choice of appropriate learning hyperparameters is a crucial step in obtaining a well-tuned model. To overcome this issue, we apply a self-adaptive differential evolution algorithm

This paper deals with the stability and critical spinning speed of a liquid-filled rotor in thermal environment with nonlinear variable-temperature. The nonlinear temperature field model of the rotor is developed by using Laplace transform. The thermal axial force exerted on the rotor as a result of the thermal effect is calculated as functions of temperature rise rate and rotor thickness ratio. Spinning

In this study, we investigate a manufacturer’s production decisions with the sequential use of raw and recycled materials in a single production process in which production setup is crucial to product conformance. Compared with raw materials, recycled materials are less expensive but are of less stable quality, thus leading to a variable amount of setup time. We embrace the maximum allowed setup time

The implications of dual sales channels (direct and traditional retail channels) and closed-loop supply chains (CLSCs) have been well recognized in the literature and in practice. In this study, we explore the reverse channel choice for the manufacturer and the design of coordination mechanisms in CLSCs in the midst of dual competitive sales channels. We consider three recycling channel structures:

An accurate characterization of rocks for the modelling of creep is an essential step toward ensuring the safety with respect to reliability of underground rock engineering. In this work, a novel variable fractional order rheological model is established to describe the full-stage creep behavior of rocks. With simpler form and fewer parameters, the proposed model is verified to have the ability for

This paper studies a retailer-dominated supply chain including a single upstream manufacturer that produces two substitutable products and a single downstream retailer that undertakes corporate social responsibility activities. The manufacturer is also regulated by a cap-and-trade policy. We first compare two optimization models for a decentralized system, one that does and one that does not incorporate

This paper investigates the effects of dynamic loads and structural damping on the nonlinear behaviors of incompressible hyperelastic spherical shells modeled by the Yeoh strain energy function. Firstly, the dynamical modeling is formulated for the nonlinear behaviors of the shells by the variational principle, and the second order nonlinear ordinary differential equation describing the radially symmetric

Mathematical models applied to livestock systems are an important tool for their analysis and planning, which can be used to improve their profitability, as well as for sanitary purposes. An age and sex structured model formulated in differential equations was developed for simulating the dynamics of a cattle herd population in a district. Since management practices determine the herd’s structure,

The salp swarm algorithm is a newly population-based search algorithm. Because the original salp swarm algorithm has low search efficiency and is easy to fall into local optimum, in this paper, we propose an enhanced salp swarm algorithm, which combines two strategies with the original salp swarm algorithm. One is the random replacement strategy, which can replace the current position with the optimal

In this paper, we propose a noise-robust online convolutional coding model for image representation, which can use the noisy images as training data. Then an alternating algorithm is utilized to convert the model into two sub-problems, the image pursuit problem and the dictionary learning problem. For the image pursuit problem, the Gauss elimination method is used to solve the equation set which is

This research seeks a practical, reliable and effective solution to the problem of nuisance vibrations experienced within robot systems. This research suggests a potential application of a thin, lightweight camera mounting arm on a robot manipulator for use during search and rescue missions and exploration. Envisioning the robot arm mounted upon a drone or a rover vehicle, the control system will need

In this work, we put forward a new algorithm for minimizing the total cost of gravity-fed water distribution networks (WDN) by optimally choosing pipe diameters. Our approach is based on network theory and heuristic procedures and aims at overcoming a number of limitations found in the current scientific literature. WDN optimization problems belong to those that are discrete, non-linear and non-convex

In this paper we aim to make possible the simulation of plasma - solid interaction in real insulating components using a set of first-principle partial differential equations. The high ratio between the conductivities of the many materials present in electrical components causes the associated numerical problem to become very stiff and this curtails the maximum allowed time step increase. To simulate

Mobile robot positioning, mapping, and navigation systems generally employ an inertial measurement unit to obtain the acceleration and angular velocity of the robot. However, errors in the internal and external parameters of an inertial measurement unit arising from defective calibration directly affect the accuracy of robot positioning and pose estimation. While this issue has been addressed by the

A three-dimensional (3D) non-hydrostatic model for simulating nonlinear and dispersive waves is extended to compute submarine-landslide-generated waves. The model uses a projection method to solve the 3D Navier-Stokes equations on a 3D grid system built from a two-dimensional (2D) horizontal mesh by adding several horizontal layers in the vertical direction. The free surface is efficiently captured

Owing to electromechanical coupling of piezoelectric fiber composites, they have been widely used in sensing and active control of aeronautic and aerospace structures. In order to describe the interface fracture of piezoelectric fiber composites, a micromechanically motivated interface model based on a cohesive zone model is developed, and it is closer to the actual debonding process including contact

Structural lightweight optimization is one of the key themes to continuously improve vehicle performance. However, most of the studies so far have not considered reliability and manufacturing issues brought about by the uncertainty of tolerances in structural lightweight optimization. In this study, a reliability-based design for lightweight vehicle structures with uncertain manufacturing accuracy

We propose an improved adaptive Type-II progressive censoring scheme, which can effectively guarantee that the test time will not exceed a certain threshold time. And the adaptive Type-II progressive censoring scheme is its special case. Based on this censoring scheme, the parameters, reliability and hazard functions of Burr-XII distribution were estimated. Firstly, we obtain the estimators of parameters

The interaction of droplets consisting of urea-water solution (UWS) with a wall is of interest for automotive exhaust gas after-treatment of Diesel engines by selective catalytic reduction (SCR). Since the impingement of tiny UWS droplets on the solid substrate is difficult to examine experimentally, little is known about the detailed dynamics of this process. In the present study, the normal impact

In the mechanical design industry, it is very time-consuming to convert actual engineering design problems into finite element models, and it is repeatedly modified during the product design process. Each time the structure is modified, computer simulation analysis is repeated, and the product development cycle becomes longer. Therefore, in this paper, a re-analysis theoretical method based on the

Compensated convex transforms have been introduced for extended real valued functions defined over Rn. In their application to image processing, interpolation and shape interrogation, where one deals with functions defined over a bounded domain, the implicit assumption was made that the function coincides with its transform at the boundary of the data domain. In this paper, we introduce local compensated

The electroosmotic flow (EOF) and ion transport within a hydrophobic conical nanopore connecting reservoirs are studied numerically. The ion transport equation is modified to consider the ion steric effect for a finite ion size. The continuum-based model compiled with the modified Poisson–Nernst–Planck and Navier–Stokes equations are adopted for analyzing the hydrodynamics and electric field. The governing

As an attempt to investigate the torsional-longitudinal vibrations of marine propeller shafting systems, this paper develops an integrated mathematical formulation to consider different aspects of the problem as clearly as possible. The previous works in this field mostly deal with the lumped-parameter or finite element simulations of the propeller and the main shaft while this paper employs a non-FEM

Submerged Floating Tunnel (SFT) is one new type of infrastructure, representing a challenge in structural engineering, both on the theoretical and operational fields. Several research work focused on this innovative structure, especially on effects of dynamic loadings such as earthquakes and sea waves. So far, the dynamic response of SFT under vertical seismic ground motion input and secondary hydrodynamic

In this work, we propose a topology optimization (TO) method using fully adaptive truncated hierarchical B-splines (ATHB-TO), where the adaptive isogeometric analysis mesh and design mesh of ATHB-TO are locally refined and coarsened simultaneously. To meet the demands of full-mesh adaptivity of ATHB-TO, a marking strategy is established based on density variances between adjacent active elements. Then

In the conventional representative elementary volume-scale models, details of fluid movement, thermal transfer and mass transport in the porous media are relatively hard to capture, while the understanding of them is crucial in many diverse engineering and environmental applications such as running nuclear power facilities or pollutant diffusion in soil environment. In this paper, a pore-scale lattice

We consider shape optimization problems for elasticity systems in architecture. A typical objective in this context is to identify a structure of maximal stability that is close to an initially proposed one. For structures without external forces on varying parts, classical methods allow proving the existence of optimal shapes within well-known classes of bounded uniformly Lipschitz domains. We discuss

Equations of motion of a hyperelastic beam under time-varying axial loading are derived via the extended Hamilton’s principle in this work, where the transverse vibration is coupled with the longitudinal vibration, and nonlinear vibrations of the beam in the subcritical buckling regime are investigated. Complex nonlinear boundary conditions of the beam are determined under some geometric constraints

Strongly nonlinear phenomena are attributes of suspension system dynamics of vehicles operated at high dynamic loads and high speeds. The causes of these phenomena are backlasches and dry friction in the mechanisms, detachments of the wheel from the roadway, impacts on the bumper elements, etc. It is well known that modelling of strong nonlinear phenomena can be based on a piecewise linear approach

New micro-devices, such as unmanned aerial vehicles or micro-robots, have increased the demand of a new generation of small-scale combustion power system that go beyond the energy-density limitations of batteries or fuel cells. The characteristics short residence times and intense heat losses reduce the efficiency of combustion-based devices, a key factor that requires of an acute modelling effort

An multi-angle filament wound(FW) model is proposed under pressure, torsion and axial loads (multiple combined loads), which can calculate stresses and displacements of arbitrary multi-layers and bring more uniform strength though FW wall thickness. Based on orthotropic constitutive relation and axisymmetric thick-walled cylinder theory, a three-dimensional (3D) analytical solution for deformations

The objective of this paper is to investigate the physical interaction of the cavitation-vortex dynamics around a 3D Delft hydrofoil by large eddy simulations combined with the Zwart–Gerber–Belamri cavitation model. Transient sheet/cloud cavitating flows around the twisted hydrofoil involves the primary and secondary cavity shedding characterized by a U-shape structure, which is consistent with previous

In this work, we propose a lattice Boltzmann method to model the electrohydrodynamic (EHD) conduction phenomenon in dielectric liquids. To incorporate the effect of the source term appeared in the charge conservation equations, some unified force terms that can be implemented locally are delicately designed in the charge evolution equations. We further validate the present model against some analytical

The motion of the cerebrospinal fluid in the spinal subarachnoid space, a slender annular canal surrounding the spinal cord, exhibits an oscillatory velocity component driven by the pressure oscillations induced by the cardiac and respiratory cycles. A time-averaged transport equation has been recently proposed for describing solute transport along the canal, circumventing the need to compute the concentration

The planar compass-gait biped robot is recognized by its simple passive morphological structure and by a complex dynamic walking system modeled by an impulsive hybrid nonlinear dynamics. Such complexity inhibits investigating the biped locomotive mechanism by means of the Poincaré map. Nevertheless, it is very difficult (and even impossible) to establish the exact closed form of the Poincaré mapping