A crane system has a variety of applications in industry and for research purposes. However, this system is underactuated and is always affected by disturbances, which compromises the controller design stage. Then, this work develops a new control scheme to control two-dimensional (2D) perturbed overhead cranes. The new proposal separates the controller into two parts. The first controller component

Recent developments in generative modeling have utilized score-based methods coupled with stochastic differential equations to sample from complex probability distributions. However, these and other performant sampling methods generally require gradients of the target probability distribution, which can be unavailable or computationally prohibitive in many scientific and engineering applications. Here

The research of bursting oscillations in neuronal models not only enriches the study of nonlinear dynamics, but also deepens the understanding of the working mechanism of the brain. A coupled FitzHugh-Nagumo (FHN) neuron model can be simulated by connecting two resistor-inductor-capacitor circuits via a resistor. Taking into account the external excitation as a slow variable, the FHN neuron model can

Nowadays, increasing pollution problems in major basins in China are becoming serious due to the acceleration of urbanization, and transboundary pollution problems are particularly deteriorating. The pollutants generated by production in the upstream area enter the midstream area with water flow and eventually reach the downstream area, causing adverse effects on the local ecological environment and

In this study, we consider a stress-strength model of the k-out-of-n system which has n statistically independent and different strength components. The components of the system are exposed to a common random stress, and the component strengths and the common stress follow different exponentiated gamma (EG) distributions. The inverse moment estimator and the maximum likelihood estimator of the reliability

We investigate the radial injection of a shear-thinning fluid, initially occupying a disk of a given radius, into the narrow gap between two parallel plates, displacing a viscous Newtonian fluid. In the Newtonian analogue, the Saffman-Taylor fingering instability occurs when a more viscous fluid is displaced by a less viscous one. Further complications arise when the displacing fluid is shear-thinning

The stiffness of a shell is conclusively influenced by the distribution of its material. To obtain the optimal material distribution of 3D spatial shells at a reasonable computational cost, this paper proposes a layer-by-layer optimization strategy with controllable deformation. In this strategy, the 3D spatial shell is divided into finite layers in the thickness dimension, and the deformations of

Wire-wrapped rods are widely used in liquid metal reactors. Under the excitation of high temperature fluids, the wire-wrapped rod will undergo flow-induced vibration, which is a key factor to evaluate the safe operation of reactors. However, there is still a lack of detailed theoretical research on flow-induced vibration of wire-wrapped rod. In order to deepen the understanding of the dynamic behavior

Static displacement is a widely used response indicator in structural health monitoring. However, traditional Bayesian model updating approaches encounter limitations when using static displacement indicators, primarily due to their weak sensitivity to structural parameters and the challenges of achieving high-precision surrogate models with limited training samples. To address these challenges, this

This study innovatively investigates the resonance characteristics and stability evolution mechanisms of piezoelectric webbed herringbone gears under time-delay control. A nonlinear dynamic model incorporating time-delay feedback control is proposed for the herringbone gear system. The amplitude-frequency response characteristics of both primary resonance and 1/3 subharmonic resonance are analytically

Considering that graphene can enhance the thermal-electrical-mechanical properties and structural stiffness of piezoelectric materials, the functional gradient (FG) graphene nanoplates (GPLs) enhanced piezoelectric structures established by combining the two have shown broader application prospects in many fields. Due to the inherent local limit definition, integer-order derivatives cannot describe

Existing studies on new energy vehicle sales forecasting are mostly based on univariate models, failing to fully consider external factors and their complex relationships. In addition, the traditional time-delay models and nonlinear models are limited to researching single effects among variables, ignoring the combined role of multiple effects in the actual system. Therefore, an accumulative time-delay

The intersection of fourth order screw systems is a challenging work in the field of mechanisms, which is very important for mechanism analysis especially for the constraint analysis of 2+2 type parallel+parallel lower mobility hybrid mechanisms. In this paper, aiming at the intersection problem of two fourth order screw systems, by constructing the ruled surface and the straight generatrix expressions

Original zeroing neural network (OZNN) models rely on matrix inversion to solve matrix problems, which reduces computational efficiency and introduces potential difficulties. Existing models, such as the norm-minimization and gradient-based approaches, do not account for both noise interference and data loss simultaneously. The enhanced anti-noise integral model addresses noise interference but does

A spatial dispersal HIV and AIDS disease model with multiple infection routes and well-mixed patches is formulated to characterize the transmission of HIV in China. We show dissipativeness and well-posedness of the model and derive the basic reproduction number, R0, followed by global dynamics of disease-free equilibrium and asymptotic profile of the endemic equilibrium. We discuss the relationship

Microwave generation in a gyrotron occurs within the interaction cavity, where a high-energy electron beam resonates with a transverse electric mode of the cylindrical cavity. Numerical tools are essential for designing and analyzing cavity operations, with the gyro-average approach traditionally fulfilling this role. This paper introduces an alternative model for fast and accurate simulation of the

The study of dynamics characteristic and control for electromechanical coupling systems has important theoretical value and practical significance in the design of industrial robots. As a nonlinear dynamics system, excitable neuron can generate multi-mode oscillations, especially the piezoelectric neuron can perceive external sound waves and vibrations and be regarded as a microcontroller. In this

The inherent rough nature of the interface would significantly affect contact performance. This work aims to propose a trans-scale contact characteristic analysis method for grinding surface, and to explore the contact characteristics of different surface topography. Based on fractal theory, the fractal features are extracted from the surface of grinding gear, and the relationship functions between

Nonlinear dynamic response of magneto-electro-elastic (MEE) laminated nanoplates, considering both the flexomagnetoelectric (FME) effect and the hygrothermal effect, are investigated. The nonlinear dynamic model for MEE laminated nanoplates has been formulated, leveraging the high-order shear deformation theory (HSDT) and the Hamiltonian principle. The von Karman equation is employed to accurately

This study employs two- and three-dimensional Langevin dynamic simulations to investigate the fundamentals of polymer-particle flocculation and assess the impact of the Kratky-Porod bending rigidity, polymer concentration, and adsorption potential strength on the resulting structures. The present work explores flocculation in enclosed computational cells under stagnant conditions, utilising a bead-spring

The widespread use of curved floating slab tracks (FSTs) on metro systems highlights their critical role in environmental vibration mitigation. To determine the mutual effect of two rails on curved FSTs and the effect of moving wheel-rail loads on track receptance, a three-dimensional frequency-domain analytical model for the curved FST is proposed based on the theories of the Euler beam, Kirchhoff

This paper addresses the formation mission for multiple fixed-wing unmanned aerial vehicles (UAVs) in three-dimensional space with a two-layer guidance and control framework. Firstly, this framework includes a three-dimensional adaptive predefined-time line-of-sight guidance law, ensuring the rapid convergence of the path-following errors. Meanwhile, a predefined-time path parameter consensus protocol

An area-varying jet nozzle structure is studied, which consists of three main segments, a flexible shell, several rigid guides, and a rigid hull, such that the thrust of the nozzle can be controlled by adjusting the area. The major difficulty in studying the area-varying nozzle dynamics is to effectively formulate the sliding motions of the variable-area flexible shells along the rigid guides, and

This paper examines the eccentric dynamic response of an embedded rigid strip foundation in layered transversely isotropic (TI) unsaturated soils influenced by groundwater level. Initially, the unsaturated-saturated soil model is established by using the triphasic Biot-type theory, with its solution is solved through the Fourier integral transform, extended precise integration method (PIM) and boundary

In this paper, an alternative non-convex Truncated Schatten Capped p-norm (TSCp) is proposed by combination of the Schatten capped p-norm and truncated nuclear norm for low-rank matrix approximation. The main contributions are twofold: first, a novel matrix completion approach based on the TSCp is introduced in the framework of alternating direction multiplier method (ADMM), and second, a low-rank

In the solidification process of alloy with current, the Lorentz force generated by current and magnetic field will significantly affect the melt flow and solute segregation behavior in the melt pool. A multi-physics field lattice Boltzmann model is proposed to investigate the effects of Lorentz force on melt flow and solute segregation in solidification of multi-component alloy. The multi-relaxation

Compared to conventional helicopters, high-speed helicopters demonstrate higher maneuverability, leading to increased maneuvering loads on transmission system. The supercritical drive shaft in these helicopters, duo to its extended span and high flexibility, is susceptible to exhibit complex dynamic behaviors during maneuvering flight, potentially leading to severe vibrations and even abnormal operation

Although we have made progress in understanding disease spread in complex systems with non-Poissonian activity patterns, current models still fail to capture the full range of recovery time distributions. This paper proposes an extension of the classic susceptible-infected-susceptible (SIS) model, called the general recovering process SIS (grp-SIS) model. This model incorporates arbitrary recovery

Deformation twins near the crack tip of metals and alloys significantly affect the crack fracture toughness. To study this particular deformation of metals or alloys, in this article, a new analytical model of a semi-infinite crack interacting with a local twinning domain near the crack tip is developed based on Kolosov-Muskhelishvili complex potentials and Green's function method. In the model, the

In applications such as digital twins, models must combine high accuracy with low computational cost. Reduced order modelling, often involving dimensionality reduction, together with data-driven model error correction, can make it possible to achieve both objectives. We focus on the use of proper orthogonal decomposition (POD), together with sample solutions from the available physics-based models

In the featured research investigation, the roles of different microstructural-dependent strain gradient tensors in the asymmetric nonlinear instability characteristics attributed to microsize arches having dissimilar boundary conditions subjected to thermal ambience amalgamated with a mechanical concentrated load applied in various positions. It is supposed that the microsize arches are constructed

The uncertainty of distribution parameters significantly impacts the outcomes of structural reliability analysis. Considering these uncertainties, the failure probability becomes uncertain and the estimation of its distribution often encounters burdensome computational effort. In this paper, to avoid repeated sampling of input random vector and performance function calls, an efficient quantitative

Due to the hyperelastic behaviors of matrix materials, hard-magnetic soft beams driven by the external magnetic fields will exhibit large and complex deformation. To accurately and reasonably calculate the mechanical properties of this structure, a theoretical model that can simulate both the axial and bending deformation entirely based on the hyperelastic mechanics is needed for current applications

In this paper, an adaptive high-order stochastic perturbation collocation method is proposed with the aim of effectively quantifying and accurately propagating uncertainty in engineering problems. By using the stochastic perturbation theory, this proposed method first performs a seventh-order perturbation expansion, and then combines the collocation method to cleverly construct a non-intrusive calculation

One important aspect of the connection between optimization models and machine learning is “constraint learning”, which involves deriving mathematical expressions for the objective function and constraints of optimization models, particularly when explicit expressions for these components are unavailable. In such situation, objective function or constraints can be learned from a labeled dataset using

Rectangular bistable composite laminate is an asymmetric double potential well system, which leads to inconsistent mechanical properties between the two stable states and diverse dynamic phenomena that rarely observed. It is interesting yet challenging to reveal the nonlinear effect of asymmetric geometry on the structural dynamic design. This study investigates the nonlinear analysis of rectangular

The aftermath of a disaster can observe increased demands for online purchases and deliveries due to a decreased local supply. The increased demands may then induce delays in item delivery. Natural disasters may also result in epidemics and critical medical situations. Thus, the deliveries can include both life-essential items, such as medicine or medical equipment, and non-essential items, such as

Block caving is a technique employed in underground mining for the extraction of minerals. It utilizes the force of gravity to facilitate the controlled fracturing of rock, thereby enabling the efficient retrieval of ores from the mine. In our pursuit of numerical simulation of this extraction process and a more profound comprehension of its influence on the mine environment, we examine variational

In this article, we review some recent work on hydrodynamics and magnetohydrodynamics (MHD) in which we attempt to build bridges between phenomenological laws of turbulence and mathematical theory. The intermittency fractal dimension factor Du to capture the non-uniformity of fluids is a key aspect in Kolmogorov's turbulence theory. To study the turbulence laws using rigorous mathematical analysis

A multi-state system with common bus performance sharing consists of a main multi-state subsystem and a reserve multi-state subsystem. The performance of any system must be prioritized to meet its own random demand, then the surplus performance is transferred to the other system that is experiencing performance deficiency. Shared reversibility exists widely in a multi-state system with a performance

In this study, a novel finite strain constitutive model that integrates viscoelasticity, viscoplasticity, and damage is proposed to characterize the mechanical behavior of thermoplastic polymers. The comprehensive constitutive framework of the proposed model employs hypoelastic theory to characterize elastoplastic responses under finite deformation as well as a continuum damage model to capture damage

This paper focuses on detecting clusterwise heterogeneous regression patterns in functional regression models with scalar response. We demonstrate that the optimal partition of the observed sample units into the best number of clusters, as well as the best regression coefficient estimates, can be obtained by minimizing an empirical Bayesian information criterion. However, due to the prospective combinatorial

To simulate the steady-state performance of the monopile-friction wheel composite foundation in ocean environments, the stratified characteristic of natural soils is non-negligible. Therefore, conducting research on the response of monopile-friction wheel composite foundation in layered soil to dynamic horizontal load is meaningful to engineering applications. In the theoretical model of this paper

Truncated conical shells are common structural elements in engineering applications. For a comprehensive understanding on the stability of such shells, a unified buckling theoretical model is proposed by considering Donnell shell theory, first-order shear deformation theory and higher-order shear deformation theory. The influence of nonlinear pre-buckling deformation is taken into account in the solution

Within the framework of linearized water wave theory, a novel wave dissipation mechanism from the viscoelastic ocean floor is proposed by solving a corresponding mathematical problem constructed in two dimensions, which involves the derivation of a complex dispersion relation due to the viscoelastic floor. The impact of the complex dispersion relation on the propagation of a Gaussian pulse in the time

Investigating the stress wave propagation mechanism in underwater concrete is significant for promotes the safety assessment and nondestructive testing of underwater engineering. However, the current understanding of this mechanism primarily relies on summarizing experimental phenomena, needing an in-depth exploration of its underlying laws. Therefore, this paper aims to establish a stress wave propagation

The high temperature induced uncertain nonlinear failure behaviour has been one of the critical issues for concurrent composite structures due to the metallic components involved. This paper presents a multivariate coupling framework for combining thermal elastoplastic based mechanical model with efficient virtual modelling technique to investigate the non-deterministic plastic responses of functionally

With the proposal of the high-order nonlocal theories for studying size effect on nano structure, due to the poor numerical convergence, the traditional transfer matrix method (TMM) can no longer meet its requirements in the research of the size effect on nano phononic crystals (PnCs), which leads to the lack of research on nano PnCs. To overcome the shortcoming, a theoretical model is established

This paper expands on Jaber and El Saadany and Hasanov et al. by distinguishing between customer perceptions of new and remanufactured (repaired) items, assuming remanufactured items are not seen as equivalent to new ones. As a new approach, our three models consider integer lot sizes for both new and repaired items, formulating the problem as a mixed integer programming (MIP) model. Unlike previous

The gas-liquid two-phase flow during the production of ultra-deep gas wells continuously impacts the production string, inducing nonlinear flow-induced vibrations, which severely compromise the integrity and safety of production string in ultra-deep gas wells. Considering the nonlinear characteristics of the production string’s material, geometry, and boundary conditions, and taking into account the

This paper addresses three key issues in fixed-time attitude control of a quadrotor unmanned aerial vehicle (QUAV): 1) the singularity problem caused by the controller tending to infinity as the system state approaches zero at a certain moment. 2) the limitation of traditional fixed-time convergence Lyapunov functions, and how to generalize the expression of fixed-time convergence to expand its applicability

The continuous increase in flight speed of aircraft makes the thermal environment more severe. The thermal environment causes significant deviations between the actual performance and design performance of the structure. Considering the impact of thermal environment during the structural design phase is crucial for a refined design. This paper proposes a novel multi-scale topology optimization method

In imaging acquisition systems, Poisson-distributed data is the natural case for many low-light image formation models. An important task in image systems is to restore the images from incomplete Poisson observations. In this paper, by exploiting the β-divergence defined in positive orthant and the triple decomposition, we propose a novel low-rank tensor completion model for Poisson observations. Different

A comprehensive comparison of twelve empirical wall-pressure auto-spectrum models developed between 1976 and 2024 is conducted to evaluate their capability and robustness in capturing spectra across a wide range of frequencies. The study collects 59 dataset pairs from public literature, covering a broad range of pressure gradient and Reynolds number conditions. Results indicate that Shubham's gene

The impacts of viral virulence and its evolution on transmission dynamics are important for the public and the policymakers during the spread of infectious diseases. To reveal the impacts of viral virulence evolution on transmission dynamics within the population, we formulate a coupled SIS-v model with viral virulence, in which transmission rate and disease-induced death rate are set as functions

In practical systems, there are many non-smooth mechanical factors, such as rigid impact and elastic impact. In this paper, the chaotic motion of a class of non-smooth hybrid constrained systems perturbed by two-frequency external excitation is studied analytically and numerically. The analysis of the system reveals the global dynamic problems of piecewise smooth dynamic models involving rigid and

Discrete time series data include count values and Z values. Count time series models have been well studied in the literature, and univariate Z-valued models also receive their own advances and progress, but the bivariate Z-valued models are rare. Existing bivariate Z-valued models are constructed using the thinning operator, which limits their flexibility. The recently rediscovered univariate mean-preserving

This article studies a non-traditional elliptic crack problem in one-dimensional (1-D) hexagonal quasicrystals (QCs). The crack surface is parallel to the quasi-periodic axis of QCs and is subjected to a pair of uniform normal loadings. A unit point dislocation problem is considered first to derive the governing equation for the crack problem with an arbitrarily shaped planar crack, based on the potential

Driven by the challenge of stabilizing formations in multi-agent systems under constraints of limited sensor measurements, this paper investigates a class of distributed formation control problems where each agent relies solely on its onboard sensing information, without access to global information. To address this, a novel distributed formation control approach is designed based on the theory of