Dynamic Analysis Research Articles

Symmetric structures and dynamic analysis of a (2+1)-dimensional generalized Benny-Luke equation

We study the symmetric structures and dynamic analysis of a (2 + 1)-dimensional generalized Benny-Luke (GBL) equation based on the Lie symmetry method, the GBL equation is an important non-integrable model of water waves. Specifically, we construct multiple exact solutions of the GBL equation and obtain its nonlocally related systems. Firstly, the Lie point symmetries and conservation laws of the GBL equation are computed, and then we get the reduced ordinary differential equation from one of the conservation laws. Multiple methods, for example, the dynamical systems method, the power series method, the homogeneous balancing method and generalized variable separation method, are used to solve the ordinary differential equation and abundant exact solutions of the GBL equation are got. Finally, we extend these exact solutions by discrete symmetries, and give three-dimensional graphs of partial exact solutions. In addition, we construct the nonlocally related PDE systems, which contains the potential systems from the conservation laws and an inverse system from a Lie point symmetry of the GBL equation. These findings reveal the dynamical behavior behind the GBL equation and broaden the range of nonlinear water wave model solutions.

Dynamical analysis of a switched social behavior model

Dynamical analysis of a switched social behavior model

Threshold dynamics of a degenerated diffusive incubation period host–pathogen model with saturation incidence rate

In this paper, we consider an incubation period host–pathogen system with degenerated diffusion. The global compact attractor of the solution of the model is investigated using the κ-contraction method. Furthermore, the basic reproduction number is defined, and we discuss the dynamic analysis of a degenerated diffusion model. The obtained theoretical results are nontrivial and can be considered a continuation of the work by Wang et al. in 2022.

Pursuing Extreme Descriptive Power and Generality in Chemical Bond Theories: A Method to Decipher "Interatomic Genomes" from Interatomic Electron Structures.

The description and analysis of chemical bonds have been difficult following the popularization of electronic structure calculations. Although many attempts have been made from the perspective of electronic structure, the sheer volume of information in the electronic structure has left contemporary chemical bond analysis methods grappling with an inescapable "Trilemma" where the model briefness, generality, and descriptiveness (descriptive power) cannot be obtained simultaneously. To push the generality and descriptiveness to their extremes, herein a general machine learning-based framework is introduced to compact chemical bonds into a detailed residue-by-residue "genome" with matched encoding/decoding tools. The framework fuses the quantum mechanical aspects, auto feature extraction, nanostructures and/or simulations, and generative models. The encoded genomes are information-dense and decodable, where 100% generality is guaranteed. The descriptiveness of genomes appears to be broader than most known models. As a proof of concept, the realization presented in this work compacts the complete information regarding two critical chemical bonds in thiolate-protected gold nanoclusters, the S-Au and Au-Au bonds, from a Bosonic-Fermionic character perspective into 8-valued genomes. The machine learning component is trained based on 26,528 density functional theory simulated electron localization function images. With an exploration of the space span for the genome, bond polarization, hybridization, intrusion of other atoms, alignments, crystal orientation, atomic motions, and more details are observed. Furthermore, it has emerged from extensive generation tests that molecules and solids can be integrated in such a concise manner than is typically achieved with purely geometric representations. To showcase the intraclass complexity of S-Au and Au-Au bonds visually, a roadmap is plotted by summarizing and correlating the similarities of 8-value-genomes. Furthermore, genomes can be associated with realistic indices easily with a simple multilayer perception architecture as a simple calculating tool. Besides, there are 3 sets of applications, including a set of chemisorption, a set of molecular dynamical analysis, and a set of ultrafast processes, showcasing the interpretability potentials of interatomic genomes in the geometric structures, kinetic properties, and vibration characteristics of molecular systems. As the framework rose to the challenge of nanoclusters from a complicated mesoscopic family of material, the displayed generality and comprehensiveness indicate that the model may "understand" chemical bonds in a machine's way.

Images of the auditor’s job and associated emotions: a dynamic analysis

This study aims to understand the images that undergraduates have of the job of auditor and the emotions accompanying those pictures. Auditing is a public interest profession focused on ensuring integrity and credibility of companies’ performance and position. First, we relied on personal visualizations expressed by the participants to analyze their images about the auditor’s job, and their changes. After that, we analyzed the emotions accompanying auditor job images, including positive emotions such as enjoyment and hope, and negative emotions such as anger, anxiety, and boredom. We also examined the evolution of the outcome by analyzing the emotions at two timepoints to capture changes in emotions accompanying the image of the auditor’s job after a session focused on the profession. The results reveal that most participants relied on traditional images, although the classical view decreased after the activity. The emotional perception of the job of auditor was mostly positive. The evidence also suggests less unpleasant emotions associated with a contemporary vision compared with a traditional view. Notably, unpleasant emotions decreased after auditing activity in both visions, and pleasant emotions increased. Study participants’ characteristics also delve into different profiles, considering emotions accompanying auditor job images. The current study combines a dynamic study of emotions and research on perceptions of the auditor’s job through personal images, which is an innovation and advancement in the auditing field owing to the importance of the affective side in critical thinking, behavior, and decision making. The findings of this study also emphasize the need that universities rethink the approach and information provided to students about the auditor’s job promoting collaboration between professional and academic worlds to improve not only perceptions about the profession but also the affective side.

Design, Dynamical Analysis, and Hardware Implementation of a Novel Memcapacitive Hyperchaotic Logistic Map

Design, Dynamical Analysis, and Hardware Implementation of a Novel Memcapacitive Hyperchaotic Logistic Map

Grid Multibutterfly Memristive Neural Network With Three Memristive Systems: Modeling, Dynamic Analysis, and Application in Police IoT

Grid Multibutterfly Memristive Neural Network With Three Memristive Systems: Modeling, Dynamic Analysis, and Application in Police IoT

The Interplay of Dietary Habits, Economic Factors, and Globalization: Assessing the Role of Institutional Quality

Background: Dietary habits are pivotal for population health and well-being, yet remain a pressing global issue, particularly in Sub-Saharan Africa (SSA), where economic instability and institutional challenges exacerbate dietary problems. Despite extensive research, there is a notable gap in the literature regarding the direct and interactive effects of institutional quality and inflationary shocks on dietary habits. Methods: This study delves into these complex interplays across 44 SSA nations from 2002 to 2022. Employing an innovative entropy method (EM) and the generalized autoregressive conditional heteroskedasticity (GARCH) modeling, the study introduces an inclusive institutional quality index and an inflationary shock predictor as crucial determinants of dietary habits in the literature. Results: The results from the panel-corrected standard error (PCSE) method and feasible generalized least squares (FGLS) model reveal that per capita GDP, school enrollment rate, government expenditures, globalization index, and urbanization are positively associated with population dietary habits, while inflationary shock, food insecurity, and unemployment rate exert negative influences. Notably, institutional quality acts as a catalyst, amplifying the positive effects of the former group and absorbing the negative impacts of the latter on population dietary habits. Additionally, a dynamic panel causality analysis confirms a bidirectional causality nexus between population dietary habits and all variables, except for inflationary shocks, which demonstrate a unidirectional causality link. Conclusions: These findings carry significant policy implications, underscoring the complex dynamics between institutional quality, inflationary shocks, and dietary habits in the region. The bidirectional causality highlights the need for holistic interventions that address economic, social, and institutional factors simultaneously. Moreover, the unidirectional causality of inflationary shocks on dietary habits suggests that stabilizing inflation is critical to protecting dietary habits. These results provide critical insights for policymakers to design targeted interventions aimed at improving nutrition, bolstering institutional frameworks, and ensuring public health resilience in the face of economic and social shocks.

Finite Element Modelling for the Dynamic Behaviour Analysis of a Structure with Hi-Lok Fasteners

The number of Hi-Lok fasteners used in the assembly of aircraft structures is very high. For this reason, an efficient modelling technique is required to accurately analyse the dynamic behaviour of the structures. In this study, a modelling technique with special emphasis on Hi-Lok modelling is proposed to analyse the dynamic behaviour of a test structure with Hi-Lok fasteners. Four different finite element (FE) models to represent the test structure with the Hi-Lok fasteners were developed using MSC Software packages. The natural frequencies and mode shapes obtained from the FE models are compared with those of the Experimental Modal Analysis (EMA) in terms of total error, computational time and memory disk usage. It was found that the model D with the simplified beams representing Hi-Lok predicts the dynamic behaviour of the test structure with an accuracy of 96.6% and with comparatively low computational time and memory disk usage. This proposed modelling scheme may provide useful approaches to aircraft researchers and engineers for the dynamic analysis of the structures.

Dynamical analysis, control, boundedness and prediction for a fractional-order financial risk system

Abstract This paper delves into the dynamical analysis, chaos control, Mittag-Leffler Boundedness (MLB) and forecasting a Fractional-Order Financial Risk (FOFR) system through an absolute function term. To this end, the FOFR system is first proposed, and the Adomian Decomposition Method (ADM) is employed to resolve this fractional-order system.The stability of equilibrium points and the corresponding control schemes are assessed, and several classical tools such as Lyapunov Exponents (LE), Bifurcation Diagrams, Complexity Analysis (CA), and 0-1 test are further extended to analyze the dynamical behaviors of FOFR. Then the global Mittag-Leffler Attractive Set (MLAS) and Mittag-Leffler Positive Invariant Set (MLPIS) for the proposed Financial Risk (FR) system are discussed. Finally, a proficient reservoir-computing (RC) method is applied to forecast the temporal evolution of the complex dynamics for the proposed system, and some simulations are carried out to show the effectiveness and feasibility of present scheme.

Stochastic Modeling and Analysis of Hepatitis and Tuberculosis Co-Infection Dynamics

Abstract Several mathematical models have been developed to investigate the dynamics of Tuberculosis (TB) and Hepatitis B Virus (HBV). Numerous current models for TB, HBV, and their co-dynamics fall short in capturing the important and practical aspect of unpredictability. It is crucial to take into account a stochastic co-infection HBV-TB epidemic model since different random elements have a substantial impact on the overall dynamics of these diseases. We provide a novel stochastic co-model for TB and HBV in this study, and we establish criteria on the uniqueness and existence of a non-negative global solution. We also looked at the persistence of the infections as long its dynamics are governable by the proposed model. To verify the theoretical conclusions, numerical simulations are presented keeping in view the associated analytical results. The infections are found to finally die out and go extinct with certainty when Lvy intensities surpass the specified thresholds and the related stochastic thresholds fall below unity. The findings also demonstrate the impact of noise on the decline in the cocirculation of HBV and TB in a given population. Our results provide insights into effective intervention strategies, ultimately aiming to improve the management and control of TB and HBV co-infections.

Numerical analysis and Schlieren visualization of gas flow dynamics inside the plasma arc cut kerf with curved cutting fronts

In plasma arc cutting (PAC), the characteristics of the gas flow exiting the nozzle significantly influence the cut quality. The high-pressure jet in PAC forms complex shockwave structures when it is incident on the metal to be cut. In this study, the flow behavior inside the kerfs of various geometries derived from an actual PAC workpiece is assessed. The shape of the cutting front in the kerf varies with the changing cutting speed. A high cutting speed yields a curved cutting front, resulting in unwanted gas flow behavior and adversely influencing the cutting performance. In this study, a computational fluid dynamics simulation model was used to analyze the effects of a curved cutting front on the gas flow behavior during the PAC process. The gas flow patterns obtained from the numerical simulations were qualitatively compared with the Schlieren experiment results. The analysis results indicated that the curvature of the cutting fronts generated oblique shockwave structures that significantly reduced the flow velocity. In particular, the weak shock structures throughout the curved cutting front gradually decreased the flow velocity. The critical flow velocity was realized in the kerf with a highly curved cutting front, beyond which the vertical penetration of the material was not possible. The shear stress lines concurred with the striation patterns on the kerf walls, thereby validating the numerical analysis results.

Mechanical reinforcement and confinement in elastomeric corn starch/bentonite nanocomposites

The mechanical reinforcement of plasticized corn starch (CS) films induced by bentonite nanoclay was investigated using dynamic mechanical analysis and rheology. Dynamic temperature scans revealed mechanical reinforcement from cryogenic to high temperatures, and two mechanical relaxations named α and α’. The lower temperature relaxation α was associated with long range cooperative molecular motions typical of the glass transition and it was associated to glycerin-rich domains, ranging from −60 °C to −40 °C. The mechanical relaxation α′ was detected in the range −30 °C to −10 °C and it may be associated to phase separated starch-rich domains. The morphology was a function of bentonite concentration, at cbentonite<3 wt% the nanoplatelets were exfoliated and c ≥ 3 wt% they were intercalated. Strikingly, at 3 wt% bentonite content the elastic modulus E′ increased drastically. The viscoelastic properties showed that the geometrical confinement exerted by the nanoplatelets also induced a decrease of fractional free volume fg and of apparent molecular weight between crosslinks Mc,app, and an increase of the activation energy Ea of the α’ relaxation. Spatial confinement in the intercalated morphology appears to be the source of mechanical reinforcement of CS/bentonite nanocomposites.

Molecular Integrative Study on Inhibitory Effects of Pentapeptides on Polymerization and Cell Toxicity of Amyloid-β Peptide (1–42)

Alzheimer’s Disease (AD) is a multifaceted neurodegenerative disease predominantly defined by the extracellular accumulation of amyloid-β (Aβ) peptide. In light of this, in the past decade, several clinical approaches have been used aiming at developing peptides for therapeutic use in AD. The use of cationic arginine-rich peptides (CARPs) in targeting protein aggregations has been on the rise. Also, the process of peptide development employing computational approaches has attracted a lot of attention recently. Using a structure database containing pentapeptides made from 20 L-α amino acids, we employed molecular docking to sort pentapeptides that can bind to Aβ42, then performed molecular dynamics (MD) analyses, including analysis of the binding stability, interaction energy, and binding free energy to screen ligands. Transmission electron microscopy (TEM), circular dichroism (CD), thioflavin T (ThT) fluorescence detection of Aβ42 polymerization, MTT (3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide) assay, and the flow cytometry of reactive oxygen species (ROS) were carried out to evaluate the influence of pentapeptides on the aggregation and cell toxicity of Aβ42. Two pentapeptides (TRRRR and ARRGR) were found to have strong effects on inhibiting the aggregation of Aβ42 and reducing the toxicity of Aβ42 secreted by SH-SY5Y cells, including cell death, reactive oxygen species (ROS) production, and apoptosis.

Synthesis and Evaluation of 18F-Labeled Phenylpiperazine-like Dopamine D3 Receptor Radioligands for Positron Emission Tomography Imaging.

The dopamine D3 receptor (D3R) is important in the pathophysiology of various neuropsychiatric disorders, such as depression, bipolar disorder, schizophrenia, drug addiction, and Parkinson's disease. Positron emission tomography (PET) with innovative radioligands provides an opportunity to assess D3R in vivo and to elucidate D3R-related disease mechanisms. Herein, we present the synthesis of eight 18F-labeled phenylpiperazine-like D3R-selective radioligands possessing good radiochemical purity (>97%), in vitro stability (>95%), and befitting lipophilicity. Based on in vitro binding assays and static microPET studies, the phenylpiperazine-like radioligands [18F]FBPC01 and [18F]FBPC03 were chosen as lead radioligands targeting D3R. Molecular docking further elucidated their binding mechanism. Radiolabeling conditions were optimized and then applied to an automated radiolabeling process, affording products with high specific activity (>112 GBq/μmol). Dynamic rat PET study demonstrated the specific binding of [18F]FBPC01 and [18F]FBPC03 to D3R in the brain ventricles and the pituitary gland. Validated by dynamic PET data analysis, biodistribution study, and metabolism analysis, [18F]FBPC03 exhibited the highest PET signal-to-noise ratio, good D3R-specific binding in the brain ventricles and pituitary gland of rats with few off-target binding, negligible defluorination, and stable brain metabolism, which indicated that [18F]FBPC03 was a promising D3R radioligand.

A study on 5-cycle fuel economy prediction model of electric vehicles using numerical simulation

This paper is a study on 5-cycle fuel economy prediction model of electric vehicles using numerical simulation. It aims to develop a prediction model for the energy efficiency of electric vehicles and compare it with the results of chassis dynamometer tests. Driving tests were conducted on a chassis dynamometer, which included various test cycles of the 5-cycle test. Using MATLAB Simulink, a vehicle dynamics analysis model for electric vehicles was constructed, and analytical research was conducted focusing on light-duty electric vehicles. By comparing and analyzing the experimental data obtained from the chassis dynamometer with the data calculated through simulation, it is possible to verify the accuracy of the electric vehicle energy efficiency prediction model. And the reliability of the simulation model was secured by comparing the experimental data obtained through chassis dynamometer test with the simulation results of the developed electric vehicle energy efficiency prediction model. There is good agreement between the experimental and simulation results. In most areas, the error rate remains below 3 %, indicating that the simulation model closely follows the experimental results from the chassis dynamometer. Based on these results, it is expected that the developed simulation model can be utilized for measuring the energy efficiency of electric vehicles.

Molecular cluster, transmission characteristics, origin and dynamics analysis of HIV-1 CRF59_01B in China: A molecular epidemiology study

PurposeThis study investigated for the HIV-1 CRF59_01B epidemic's spatiotemporal dynamics and its transmission networks in China. MethodsBetween 2007 and 2020, a total of 250 partial pol gene sequences of HIV-1 CRF59_01B were collected from four regions (10 Chinese provinces). Phylogenetic tree construction and cluster identification were then performed. The Bayesian skyline and birth–death susceptible–infected–removed models were employed for the phylodynamic analyses of subtypes and large clusters, respectively. Phylogenetic analyses and trait diffusion of these sequences were performed using Bayesian phylogenetic methods (beast-classic package). Distance-based molecular network analyses were performed to identify putative relationships. ResultsUsing a genetic distance threshold of 1.3 %, We identified 45 clusters that included 62.40 % (156/250) of the sequences. Three clusters (6.67 %, 3/45) had 10 or more sequences, and were considered "large clusters". Six clusters (13.33 %) included sequences from different regions (Southeast, Northeast, Southeast, and Central China). Thirteen clusters (28.89 %) included sequences of men who had sex with men only, three clusters (6.67 %) included sequences of heterosexuals only, and 12 clusters (26.67 %) included sequences of both groups. The substitution rate of CRF59_01B was 1.91 × 10–3 substitutions per site per year [95 % highest posterior density (HPD) interval: 1.39 × 10−3–2.49 × 10−3)], the time to the most recent common ancestor of CRF59_01B was to be 1992.83 (95 % HPD: 1977.97–2002.81). A Bayesian skyline plot revealed that the effective population size of CRF59_01B increased from 2000 to 2015 and remained stable after 2015. The large clusters showed continuous growth from 2013 to 2020. Phylogeographic analysis showed that CRF59_01B B most likely originated in Southeast China, with a posterior probability of 97.44 %, and then spread to other regions. ConclusionsOur study revealed the temporal and geographical origins of HIV-1 CRF59_01B as well as the process of transmission among various regions and risk groups in China, which can help develop targeted HIV prevention strategies.

Design and dynamic analysis of a spanwise morphing wing for Mars exploration

The application of spanwise morphing wings makes it possible to transport and launch large-size Mars exploration UAVs. This article proposes a modular variable spanwise morphing wing for high-aspect-ratio aircrafts, and analyses the characteristics of the morphing wing by theoretical analysis, numerical simulation and experimental verification. The novel spanwise morphing wing is based on the Sarrus-inspired deployable structure, which can increase the wing's lift by changing the spanwise length. The pre-strain torsion springs are assembled to provide the initial driving moment of the morphing mechanism. A regular triangle cross section is selected by evaluating the bending and torsional stiffness, and deployable triangular prism mechanisms are identified. Through releasing the pre-strain torsion springs to achieve expansion and implant Sarrus linkages along the straight motion paths. A lockable structure is designed, and the main factors affecting the self-locking property are analysed. A rigid origami skin is proposed, which maintains the airfoil's continuous smoothness after spanwise morphing. The kinematics of the spanwise morphing wing unit is developed using the Lagrange equation, and the theoretical models of morphing wings with different numbers of units are obtained. The unit numbers influence fully expanded time, and the time decreases gradually along the wingtip's direction. Finally, a one-way fluid-structure interaction analysis is performed to investigate the spanwise morphing mechanism and origami skin response under aerodynamic loads. Results show that the skeleton mechanism's maximum stress is below the material's yield strength, and the origami skin's maximum out-of-plane deformation is less than 0.5% of the wing chord, which provides a necessary theoretical basis for applying the spanwise morphing wing.

Multilayer network analysis of idiosyncratic volatility connectedness: Evidence from China

This paper proposes multilayer networks, including lagged, contemporaneous, and long-run networks, to examine the idiosyncratic connectedness among Chinese financial institutions. We explore the topology of multilayer networks through static and dynamic analysis to capture the information transmission mechanism of idiosyncratic risks. Moreover, we investigate the drivers influencing idiosyncratic connectedness across financial institutions. We find that idiosyncratic risk contagion among financial institutions is stronger in the long-run network. At the same time, we note that the three networks contain different connection structures, which means that the information transmission mechanism of idiosyncratic risks is heterogeneous in multilayer networks. In addition, when the financial system is under stress, we observe that the contemporaneous effect of idiosyncratic connectedness rises rapidly. Institutional level analysis shows that diversified financial institutions play active roles in the lagged network, securities institutions are transmitters of contemporaneous information spillovers, and banking institutions are the main drivers of the long-run network. Finally, our study shows that size is the main factor driving idiosyncratic risk spillovers among financial institutions.

Structural design and dynamic analysis of a metal rubber composite gear pair

This paper introduces a metal rubber composite gear for gear vibration reduction. A comprehensive structural design calculation program is developed for the metal rubber composite gear pair. The design incorporates a gap between the tooth ring and the hub to accommodate thermal expansion and contraction, ensuring smooth transmission without jamming or seizing. The design process takes into consideration the compression and damping properties of the metal rubber material. A significant variable in the design process is the relative density of the metal rubber material. It is utilized to calculate the torsional stiffness, starting friction torque, and dynamic performance of the composite gear pair. To guide and optimize the design process, a nine-degree-of-freedom dynamic model is employed for dynamic analysis. The vibration reduction effect of the metal rubber composite gear is validated through numerical simulations and experimental testing. The results confirm the efficacy of the gear in reducing vibrations. This paper provides valuable insights and guidance for future designs focused on gear vibration reduction, paving the way for further advancements in this field.