Mobile robots have been widely used in various military applications, where an efficient and robust trajectory planner is of vital importance. In this paper, we focus on the sneaking trajectory planning of reconnaissance robots with consideration of uncertainty in the geometric parameters of the watchtower's searchlight. By analyzing the motion equations and the mission requirements, the trajectory

This paper proposed a new theoretical model for analyzing the submerged floating tunnel(SFT) under moving load, whose boundary at two ends was regarded as elastic constraint, and the anchor cable was simplified as the discrete spring support. Besides, the tunnel joint was simulated as a flexural spring to connect two adjacent tube segments.The modes and natural frequencies of the model were solved

This study addresses the deficiency of means for analysis of planar arbitrarily curved microbeams. More precisely, a formulation is developed for static analysis employing the modified couple stress theory and the Euler-Bernoulli beam model. Geometric and kinematic descriptions of a slender three-dimensional continuum body are consistently reduced to those of its beam axis. A systematic framework is

For elastodynamic problems, significant effort has been exerted by numerical researchers to eliminate the reflection of outgoing elastic waves at the boundary of the computational domain. Eliminating these reflection is very important for correctly analyzing the dynamic response of various structures. In this paper, the enriched degree of freedom method is first proposed to absorb outgoing elastic

Drug-loaded hydrogels provide a means to deliver pharmaceutical agents to specific sites within the body at a controlled rate. The aim of this paper is to understand how controlled drug release can be achieved by tuning the initial distribution of drug molecules in a hydrogel. A mathematical model is presented for a spherical drug-loaded hydrogel. The model captures the nonlinear elasticity of the

Pile groups for the bridge and jacket foundations in the marine or traffic geotechnical engineering are significantly influenced by the current scour in service. Under the effects of scour and dynamic load, the capability of the pile foundations to resist deformation is reduced and thus causes structural failure. This paper presents a FEM-ALEM coupling approach to study the dynamic interaction between

To cope with higher degenerations, some previous results about computable normal forms are extended for two dimensional systems having a pseudo-focus within its discontinuity line. More precisely, it is shown how the standard theory of normal forms allows the analysis of pseudo-focus points when the contact order with the discontinuity boundary, being even for both vector fields, is different from

This paper presents a bi-level blood supply chain network under uncertainty during the COVID-19 pandemic outbreak using a Stackelberg game theory technique. A new two-phase bi-level mixed-integer linear programming model is developed in which the total costs are minimized and the utility of donors is maximized. To cope with the uncertain nature of some of the input parameters, a novel mixed possib

Gradual correction using external fixator has been advocated as a minimally invasive solution for limb deformity and is widely used in the clinic. This treatment manner requires a long-term distraction process, which is guided by a preplanned correction path. However, bone cross-section (BCS) collision and soft tissue (ST)-distraction rod (DR) collision may occur on the path and then affect the continuity

This paper introduces a general class of multivariate distributions for rates and proportions on the basis of the multivariate elliptical distribution. We derive various general properties of this multivariate distribution. The model parameters are estimated using the maximum likelihood estimation method. In particular, we have considered parameter estimation in detail for two special cases of this

The inversion of contamination source characteristics is of great importance to groundwater remediation and risk management. The surrogate model-based simulation-optimization method is the most commonly used groundwater contamination source inversion (GCSI) approach. However, the static surrogate model and the genetic algorithm (GA) suffer from inaccuracy and instability problems when the nonlinearity

The present work investigates the existence/nonexistence of instability regions for a parametrically excited linear gyroscopic system. To achieve this goal, a new approach is proposed to determine the boundaries of parametric instability regions. As long as the gyroscopic system's undamped equations of motion are derived, one can easily use this approach to determine its instability regions. For convenience

In this paper, we present a new model to simulate the formation, evolution, and break-up of a thin film of fluid flowing over a curved surface. Referred to as the discrete droplet method (DDM), the model captures the evolution of thin fluid films by tracking individual moving fluid droplets. In contrast to existing thin-film models that solve a PDE to determine the film height, here, we compute the

Considering the strong nonstationarity and nonlinearity of measured displacement, a displacement prediction model of concrete dams is proposed using variational mode decomposition (VMD), twin support vector regression (TSVR) and gated recurrent unit (GRU). Firstly, VMD is adopted to decompose the measured displacement into several signals according to the time series features. Then, K-means clustering

This paper presents the first 3D entirely Lagrangian meshfree hydroelastic FSI (Fluid-Structure Interaction) solver for reproduction of incompressible fluid flows interacting with anisotropic/isotropic composite elastic structures as well as the first Hamiltonian SPH for anisotropic structures. To achieve this development, we have carefully (i) reformulated the HSPH (Hamiltonian Smoothed Particle Hydrodynamics)

We present a meshfree generalized finite difference method for solving Poisson’s equation with coefficients containing jump discontinuities up to several orders of magnitude. To discretize the diffusion operator, we formulate a strong form method that uses a smearing of the discontinuity, and a conservative formulation based on locally computed Voronoi cells. Additionally, we propose a novel conservative

Hydrofoil sections operating near the free surface are highly prone to marine cavitation, known as the appearance of vapor cavities inside the initially homogenous liquid medium. Advances in computational and experimental research have led to a better understanding of this multiphase phenomenon, thus enabling researchers to predict and alleviate its adverse effects on hydrofoil performance. In this

In stochastic reserving, the incurred outstanding liabilities of general insurance companies result in incomplete claims because of truncation and censoring. It is necessary for insurance companies to predict liabilities in risk management. We propose a model that allows the incorporation of heterogeneity among policies, which is important for loss reserving. The incompleteness of observation data

In nervous system, a non-synaptic communication between neurons, known as the ephaptic coupling, emerges depending on electromagnetic induction which is induced by extracellular electric fields. In this paper, a multilayer neuronal network is constructed by adopting ephaptic coupling between layers, and dynamical robustness of multilayer neuronal networks with inter-layer ephaptic coupling is analyzed

Shaft-tunnel junction is a typical case of critical underground joint structures. The abrupt structural change between the shaft and the tunnel makes it particularly susceptible to seismic damages. The focal point of this paper is the dynamic responses of shaft-tunnel junction under P-SV waves, for which a dynamic analytical model is developed. The shaft is assumed to be conditionally rigid, and the

Mode-coupling vibrations in thickness-extensional piezoelectric thin-film bulk acoustic wave resonators (FBARs) with initial stress operating in the ultra-high frequency (UHF) range are investigated by employing the Frequency Spectrum Quantitative Prediction (FSQP) method. The uniaxial uniform initial stresses along the in-plane and thickness directions are separately considered. The dispersion relation

With the development of large and complex aerospace products, industrial robots with automatic guided vehicles have been increasingly used in manufacturing and assembly, such as drilling, riveting, and milling, due to their advantages of multi-station machining and high expandability. However, they are prone to vibration when excited by machining forces because of their low rigidity, which leads to

Contact behavior of gear teeth plays a key role in modeling and analysis of geared systems. To reasonably evaluate the time-varying contact characteristics of spur gear systems, a new load-dependent time-varying meshing stiffness model incorporating elastic contact stiffness, temperature stiffness and oil film stiffness is developed. Asperity pressure and lubricant pressure are considered for the oil

This paper proposes a finite-time controller for an unmanned aerial vehicle in the presence of Figures/uncertainties using fractional-order terminal sliding mode. First, contrary to existing fractional-order backstepping sliding mode controllers, this paper introduces a new control approach for quadrotor position control, which is based on fractional-order fast terminal backstepping sliding mode control

The reasonable setting of guides can directly improve the evacuation capacity in the subway station. The important role of guide assignment scheme and evacuation path planning of guided passengers is particularly prominent. Considering the distribution of passengers in the station, one contribution is that an assignment scheme of the initial number and location of guides is firstly established based

We have studied the electroosmotic flow (EOF) of a non-Newtonian viscoplastic fluid, modeled as a Herschel-Bulkley (H-B) fluid, through a single hydrophobic nanopore in a uniformly charged solid hydrophobic membrane separating two identical reservoirs. An interfacial slip velocity develops when the viscoplastic fluid is strained over a hydrophobic surface. It is well established in the context of Newtonian

To ensure the stability of a young seedling of a tree and proper rooting, tree stems are usually staked with one, two or three stakes. In this paper, we present a mathematical model and its approximations of a nonlinear biodynamical system in the form of a complex discrete structure on a cantilever. The nonlinear biodynamical system corresponds to a staked tree with one stake. The geometric nonlinearity

The planting and harvesting of medicinal plants have characteristics that differentiate them from other crop types and complicate their planning. For example, drug processors do not require large quantities of product to be harvested but have a high concentration of active molecules. There is no evidence for any optimization tool to support the planting and harvesting of such plants. Given this sector's

This paper investigates the cluster synchronization (CS) for a class of complex dynamical networks (CDNs) with parameters mismatch to the selected cluster pattern. An impulsive control strategy with multiple control gains is proposed. Particularly, the possible packet loss phenomenon in control input is fully considered, and it is characterized by a series of impulse packet loss rate (iPLR) conditions

Thermo-electromechanical coupling analysis at micro/nano-seconds appears to be particularly important, where strain and electric relaxation effects will increase significantly in such case. So far, although temperature-rate-dependent theory of piezoelectric thermoelasticity has been historically proposed, it may be no longer hold anymore as relaxation effects both in electrical and strain fields have

In this paper, we propose a new mixed finite element method for a swelling clay model with secondary consolidation, which is a process of the volume of saturated clay decreasing with time after the completion of primary consolidation. To better describe the multi-physics processes underlying in the original model, we firstly reformulate the swelling clay model with secondary consolidation by introducing

In this work, a general method is proposed to solve a wide class of high-order boundary value problems governing the dynamics of beams equipped with vibration absorbers. The method relies on one-dimensional beam theories and theory of generalized functions to model the reaction forces of the absorbers. The key step consists in deriving, via Laplace transform, the Green’s function of a linear differential

This paper studies the finite-time stabilization (FTS) of nonlinear systems with impulsive disturbance, where the effect of saturation structure on the control input is fully considered. By establishing a potential relationship between saturation structure and impulsive disturbance, some FTS criteria are presented via a class of saturated control input, where estimations of domain of attraction and

Near-infrared light-controlled transdermal drug delivery (NIRTDD) has several advantages over traditional delivery methods, and it is now undergoing extensive research. One prominent aspect of NIRTDD is the possibility of keeping the drug concentration in its optimal therapeutic window using a suitable near-infrared light protocol. The problem is that this ideal protocol is usually unknown. In this

A new triple-layer phononic crystal (PC) composite beam model is proposed, which binds two piezomagnetic layers to conventional PCs coupling the microstructure and flexoelectric effects. A variational approach is employed to derive the relevant equations of motion and boundary conditions (BCs), followed by using the Bloch theory and transfer matrix method (TMM) to accurately calculate the bandgap of

A major challenge in the vibration performance assessment of structures under crowd jumping loads is the lack of efficient prediction models. With the challenge in mind, this study develops a multi-mode response spectrum for multi-harmonic crowd jumping loads to predict the root mean square value of structural accelerations according to the stochastic vibration theory. The response spectrum is applicable

Wind-induced or current-induced torsional vibration is a long-neglected issue for offshore engineering (e.g., offshore wind turbines, offshore oil platforms, etc.). As the dimension of the pipe pile implemented offshore increases dramatically, the one-dimensional rod theory can no longer precisely compute the dynamic torsional impedance. This paper proposes a novel 3D torsional soil-pile interaction

This work presents an energy dissipation analysis for large-strain cylindrical cavity expansion problem in cohesive-frictional soils. Based on the unified strength criterion and the non-associated flow rule, the process of cavity expansion in cohesive-frictional soils is regarded as an energy conversion problem. The energy dissipation solution for large-strain cylindrical cavity expansion is obtained

Induction heating is used in many industrial applications to heat electrically conductive materials. The coupled electromagnetic-thermal induction heating process is non-linear in general, and for ferromagnetic materials it becomes challenging since both the electromagnetic and the thermal responses are non-linear. As a result of the existing non-linearities, simulating the induction heating process

In order to determine all the required algebraic relationships among the parameters of the grey possibility functions with the given final clustering results, a matrix-based approach for the bidirectional perspective of the grey clustering model based on the grey possibility functions is developed in this work. The definition of the bidirectional problem in a grey clustering model is defined. The matrix

In this study, the singular boundary method (SBM) is extended to simulate the dynamic response of the half-space saturated soils in the frequency domain. The SBM employs the fundamental solutions of the governing equations as basis functions. Thus, the domain of interest can be discretized into several source points merely on the boundary, which makes the SBM available to describe the wave propagation

A diffusion model is considered to represent the time evolution of coastal profiles, over the time span of several years ahead. This is important in view of both, natural and anthropic activities, which affect and tend to modify the environment near the sea coastal lines, river’s estuaries, and harbors. The final aim is to make useful predictions for the depth profile evolution, basing on real available

Epidemiological models have become powerful tools for studying and understanding the characteristics and impact of transmitted diseases in a population. However, these models usually require specifying several values of input parameters obtained from experimental data, characterized by high uncertainty levels due to biological variation. This situation is evident for models that simulate the transmission

A cellular automaton (CA) depicting the dynamics of the Covid-19 pandemic, is set up. Unlike the classic CA models, the present CA is an enhanced version, embodied with contact tracing, quarantine and red zones to model the spread of the Covid-19 pandemic. The incubation and illness periods are assimilated in the CA system. An algorithm is provided to showcase the rules governing the CA, with and without

To develop the miniaturization of the electromagnetic harmonic movable tooth drive system, a novel configuration with an inner stator is proposed to create a great compressed structure. To avoid undesirable design parameters that lead to bifurcation and chaotic behavior of the flexspline, the nonlinear dynamic equations of the flexspline are established, and the Duffing equation and analysis results

Soil-structure interaction problems are an important issue in the research field of geotechnical engineering. Understanding and modeling the soil-structure interaction problems is thus critical. Such interaction problems involve the mechanical behaviors of both soil and structure as well as their complex interaction. Discontinuous deformation method (DDA) is appropriate for modeling mechanical behavior

Graded nanostructured (GNS) materials has attracted widespread attention in the recent years. The gradually changed microstructures and mechanical properties from the surface to the interior layer in graded nanostructured materials can improve the mechanical properties of the surface. The motivation of this research was to explore the effect of size effect, adhesion and gradient on the mechanical properties

In this study, the weakened fractional-order accumulation operator for alleviating the ill-condition of discrete grey system models with the aim of improving the grey system theory is proposed. It is found that the weakened fractional-order accumulation operator composed of the improved fractional-order accumulation operator and the multiplicative transformation can not only alleviate the ill-condition

Vibrating screen is the pivotal equipment to separate drilling fluid and cuttings during oil exploitation. However, some inherent defects such as low screening efficiency, vibration fatigue and structural failure are observed in the most of conventional vibrating screens with single screen box and same-frequency actuation. For the above-mentioned problems, a newly dynamic vibration absorption device

Manifestation of stationary and oscillatory convection and secondary instabilities due to a chemical reaction in a two-component convective fluid system is reported in the paper by considering idealistic as well as physically realistic boundaries. Using a normal mode solution, analytical expression of the critical Rayleigh number for a stationary and oscillatory disturbances, and the natural frequency

The seismic response of a concrete planar frame containing shape memory alloy (SMA) wires is presented based on a mathematical model. The various distributions of SMA wires in the thickness of the concrete frame are assumed. The logaritmic shear deformation (LSDT) is applied for modeling of the structure. With respect to the phase transformation of SMA wires, the motion equations are coupled with the

A coupled ferrohydrodynamic interface-tracking model is introduced for the analysis of the equilibrium, linear stability, and modal response of magnetic liquid interfaces in surface tension-dominated axisymmetric multiphase flows. The incompressible viscous mass and momentum balances are solved together with the steady-state Maxwell equations by following a monolithic solution scheme. The method is

In this paper, a practical output feedback disturbance rejection controller holding the desired dynamic behavior is proposed for precise movement control of hydraulic systems with disturbances, unknown states, and severe measurement noise. To relieve the noise and deal with unknown states, the estimated values obtained by the state observer are used to replace the actual states. Considering the matched

Motivated by the low-carbon economic development, we study the competition issues in apparel supply chains considering consumers’ low-carbon preferences. In this paper, we construct static and dynamic decision-making models under different game scenarios based on the centralized and decentralized frameworks. Firstly, we explore the critical conversion conditions between the centralized and decentralized

In our previous work, macroscopic models for multi-species diffusion/heterogeneous reaction with different diffusion coefficients in porous media were derived from the homogenization technique based on a spectral approach (Le et al., Applied Mathematical Modelling, 104, 666–681, 2022). This work aims to analyze numerically the properties of the eigenvalues and eigenfunctions of the spectral problem

Fractional derivatives appear to be a convenient and effective tool for describing complex processes, systems, and material characteristics. In this study these mathematical operations are used to modify an exemplary non-linear system (the Duffing system) by adding additional fractional components. Numerical analyses were performed to check how the orders of derivatives in fractional terms affect the

The impact of solid polarization of a dielectric membrane on ion transport in a conical nanopore drilled through a membrane is studied by considering ions as finite-sized dielectric charged spheres. The excess polarization of the hydrated ions creates a dielectric decrement. A mean-field-based approach is adopted by modifying the Nernst-Planck equation to incorporate the ion steric interactions, the

This paper proposes a modeling method of rotating hard-coated drum-disk structures considering the strain-amplitude dependency of coatings and studies the veering of frequency curves and nonlinear coupled vibration. Firstly, Sanders’ shell theory and Kirchhoff's plate theory are used to derive the energy expressions of the hard-coated drum and hard-coated disk, respectively. The arbitrary multi-arc

Monte Carlo sampling methods are the standard procedure for approximating complicated integrals of multidimensional posterior distributions in Bayesian inference. In this work, we focus on the class of layered adaptive importance sampling algorithms, which is a family of adaptive importance samplers where Markov chain Monte Carlo algorithms are employed to drive an underlying multiple importance sampling

Rapid development and wide application of cyber-physical systems (CPS) have created the possibility of remotely monitoring product working cycles. This indicates that CPS can provide the technological support required for designing manufacturers’ warranties integrated with working cycle and for modelling users' (or consumers') random maintenance policies sustaining the reliability of the product through