Dynamical Theory Research Articles

Protracted Kondo coherence with dilute carrier density in cerium based nickel pnictides

Nozières' exhaustion theory argues that the temperature for coherently screening of all local moments in Kondo lattice could be much lower than the temperature of single moment screening in case of insufficient conduction electrons. Experiments indicate that cerium based nickel pnictides CeNi2−δAs2(δ≈0.28) is an ideal material to exam such protracted Kondo screening. Using density functional theory plus dynamical mean-field theory, we found CeNi2As2 presents a transition from the local moment states to the coherent Kondo screening states under compression, accompanied by topological changes of the Fermi surface. Similar phase transition could be driven by chemical pressure via the isovalence As→P substitution. The derived coherent Kondo temperature Tcoh is much lower than the single-impurity Kondo temperature TK due to the diluted Ni-3d conduction electrons, indicating the protraction of Kondo screening in crystal. In contrast to structurally analogous layered iron pnictides, the electronic structures of the present systems show strong three-dimensionality.

Strategic Collaborations and Performance of Oil Marketing Firms in Kenya

Purpose: Little attention has been paid to the effect of strategic collaboration on performance of oil marketing firms in Kenya. As a result, it is vital to investigate the effect of strategic collaboration on performance of oil marketing firms in Kenya. The study's particular aim was to investigate the impact of strategic alliances, mergers and acquisitions, franchising, and joint ventures on performance of oil marketing firms in Kenya. Four theoretical reviews are included in this research paper: Resource Based Theory, Transaction Cost Theory, Trust Theory and Dynamic Capability Theory. Methodology: Using descriptive research approaches, this study evaluated the data and offered findings. Over a certain time period, data was collected from oil marketing firms in Kenya. The research relied on primary data gathered via structured questionnaires as well as secondary data. The study's target population was Kenya's oil marketing firms in Kenya. The study also used stratified random sampling. The study's data was collected using Google forms and sent through email. The questionnaire data was sorted, classified, and analyzed using Statistical Packages for Social Sciences (SPSS). Findings: finding demonstrate that savvy partnerships among Kenyan oil marketers improve performance. Businesses appreciate shared storage, cooperative networks, and specialized service sharing for increasing operational efficiency and competitiveness. Statistical analysis reveals that these partnerships influence company performance, accounting for 81.5% of the variance, with a strong correlation coefficient (R = 0.903) and a substantial ANOVA F-value. Unique contribution to theory, Policy and Publication: To obtain additional information and draw meaningful conclusions about the variables of interest, descriptive studies was conducted where survey was used to provide a snapshot of the population. Tables was used to display the data. This study will be useful to academics and researchers in finance and economics.

Paramagnetic susceptibility and spin correlation function of ferromagnetic metals in the critical region

We study paramagnetic characteristics of ferromagnetic metals near the Curie temperature TC using the dynamic spin fluctuation theory. In contrast with most first-principles calculations, our results for the uniform paramagnetic susceptibility show a clear deviation from the Curie–Weiss law. We demonstrate that the susceptibility and correlation radius have the power-law behavior at temperatures up to 1.1–1.15TC, which gives an estimate for the region of critical temperatures in metals. Our theoretical critical exponents for Fe, Co, and Ni are in reasonable agreement with the low-field susceptibility measurements and neutron scattering experiments.

Multi-relation spatiotemporal graph residual network model with multi-level feature attention: A novel approach for landslide displacement prediction

Accurate prediction of landslide displacement is crucial for effective early warning of landslide disasters. While most existing prediction methods focus on time-series forecasting for individual monitoring points, there is limited research on the spatiotemporal characteristics of landslide deformation. This paper proposes a novel Multi-Relation Spatiotemporal Graph Residual Network with Multi-Level Feature Attention (MFA-MRSTGRN) that effectively improves the prediction performance of landslide displacement through spatiotemporal fusion. This model integrates internal seepage factors as data feature enhancements with external triggering factors, allowing for accurate capture of the complex spatiotemporal characteristics of landslide displacement and the construction of a multi-source heterogeneous dataset. The MFA-MRSTGRN model incorporates dynamic graph theory and four key modules: multi-level feature attention, temporal-residual decomposition, spatial multi-relational graph convolution, and spatiotemporal fusion prediction. This comprehensive approach enables the efficient analyses of multi-source heterogeneous datasets, facilitating adaptive exploration of the evolving multi-relational, multi-dimensional spatiotemporal complexities in landslides. When applying this model to predict the displacement of the Liangshuijing landslide, we demonstrate that the MFA-MRSTGRN model surpasses traditional models, such as random forest (RF), long short-term memory (LSTM), and spatial temporal graph convolutional networks (ST-GCN) models in terms of various evaluation metrics including mean absolute error (MAE = 1.27 mm), root mean square error (RMSE = 1.49 mm), mean absolute percentage error (MAPE = 0.026), and R-squared (R2 = 0.88). Furthermore, feature ablation experiments indicate that incorporating internal seepage factors improves the predictive performance of landslide displacement models. This research provides an advanced and reliable method for landslide displacement prediction.

Large-Scale Group Decision Making with Dual Feedback from Community Residents Based on the Organizational Invisible Field

In China, communities function as grassroots self-governing bodies, and the enhancement of public participation in community governance has remained a central focus of study. This paper applies the Large-Scale Group Decision-Making (LSGDM) method to the process of community self-governance and proposes a dual feedback group consensus decision-making model that takes into account the unique social relations among residents. Firstly, the concept of the Organizational Invisible Field—formed in communities by intangible social capital such as positional power and interpersonal relationships within the organization—is introduced. The definition of Invisible Field Force is utilized to measure the influence of these forms of capital on social relationships. Subsequently, drawing on field dynamic theory, the process by which residents’ preferences within the organization are shaped by the action of Invisible Field Force is explored. Secondly, acknowledging that invisible relationships can be affected by dynamic interactions during the decision-making process, the Invisible Field Force change model is constructed. Building on this, a dual feedback consensus coordination mechanism—encompassing both in-organization members and all residents—is designed. Finally, the validity and utility of the model are verified through case studies and sensitivity analyses.

Invariant solutions, lie symmetry analysis, bifurcations and nonlinear dynamics of the Kraenkel-Manna-Merle system with and without damping effect

This work investigates the Kraenkel-Manna-Merle (KMM) system, which models the nonlinear propagation of short waves in saturated ferromagnetic materials subjected to an external magnetic field, despite the absence of electrical conductivity. The study aims to explore and derive new solitary wave solutions for this system using two distinct methodological approaches. In the first approach, the KMM system is transformed into a system of nonlinear ordinary differential equations (ODEs) via Lie group transformation. The resulting ODEs are then solved analytically using a similarity invariant approach, leading to the discovery of various types of solitary wave solutions, including bright, dark, and exponential solitons. The second approach involves applying wave and Galilean transformations to reduce the KMM system to a system of two ODEs, both with and without damping effects. This reduced system is further analyzed to investigate its bifurcation behavior, sensitivity to initial conditions, and chaotic dynamics. The analysis reveals the presence of strange multi-scroll chaotic dynamics in the presence of damping and off-boosting dynamics without damping. In addition to these approaches, the study also applies the planar dynamical theory to obtain further new soliton solutions of the KMM system. These solitons include bright, kink, dark, and periodic solutions, each of which has been visualized through 3D and 2D graphs. The results of this research provide new insights into the dynamics of the KMM system, with potential applications in magnetic data storage, magnonic devices, material science, and spintronics.

Harvesting strategies in ecological systems: Evaluating their efficiency in infection dominance

In population biology, the interplay between prey and predators in the presence of infection can give rise to complex dynamics. On the flip side, implementing harvesting is an infection control measure. In the present work, we use the dynamical system theory to discuss the dynamics of the harvested prey–predator system in the presence of infection in prey species. Detailed mathematical and numerical evaluations have been presented to discuss the susceptible‐free state, infection‐free state, predator‐free state, species coexistence, stability, and occurrence of various bifurcations (saddle‐node, transcritical, and Hopf bifurcation). The study reveals the impact of harvesting parameters on the dynamics. Interestingly, we observe that an infection‐free state could be achieved by varying the harvesting parameter under all three harvesting schemes (linear, quadratic, and nonlinear). Moreover, with the help of reproduction number, we claim that linear harvesting is more effective in controlling the infection than quadratic and nonlinear harvesting provided the half‐saturation constant for nonlinear harvesting is greater than a threshold value ; otherwise, nonlinear harvesting is more effective. Also, the system can support more susceptible prey in the presence of harvesting. The present theoretical study suggests different threshold values of implemented harvesting to control the disease.

Three-leg bosonic triangular ladder in a staggered magnetic field

Based on the dynamical Gutzwiller mean-field theory, we investigate the ground states of interacting bosons on a triangular ladder lattice, which is comprised of three legs, and in the presence of a staggered magnetic flux. As a consequence, the vortical lattice phase with triangular chiral vortical currents is discovered, which particularly features a biased ladder structure, characterized by larger populations on the inner leg than those of the two outer legs. This similar structure could be either figured out on the four-leg and five-leg flux ladders, interpreted by the Bose-Hubbard model. The variations of currents and populations induced by the growth of number of legs are discussed. We further identify a type of particle current going through a zigzag-shaped outline. It is also necessarily accompanied with the biased configuration on the distribution of population, and could be generalized to the four-leg or five-leg model.

Analysis of the Vertical Dynamic Response of SDCM Piles in Coastal Areas

The stiffened deep cement mixing (SDCM) pile, as a new type of rigid–flexible composite pile, significantly enhances the vertical bearing capacity of traditional precast piles, thus holding broad application prospects in the substructure construction of nearshore bridges and marine energy structures. This paper investigates the vertical dynamic response of SDCM piles through theoretical derivation and parameter analysis. Firstly, based on elastic dynamics theory and the three-phase porous media model, vertical vibration control equations for both SDCM piles and fractional-order viscoelastic unsaturated soils are established. Secondly, theoretical derivations yield exact analytical solutions for the surrounding dynamic impedance, top dynamic stiffness, and dynamic damping of the SDCM pile. Finally, through numerical examples and parameter studies, the impact mechanisms of physical parameters in the SDCM pile–unsaturated soil dynamic coupling system on the top dynamic stiffness and dynamic damping of the SDCM pile are analyzed. The research results presented in this paper indicate that reducing the radius of the rigid core pile while increasing the thickness of the exterior pile has a positive effect on enhancing its vibration resistance. Additionally, increasing the length of SDCM piles contributes to improved vibration performance. However, an increase in the elastic modulus of the cement–soil exterior pile is detrimental to the vibration resistance of the rigid composite pile. On the other hand, an increase in the elastic modulus of the concrete core pile only enhances its ability to resist vibration under low-frequency load excitation. Furthermore, enlarging the soil saturation, decreasing the intrinsic permeability, and enlarging the soil relaxation shear modulus have a significant positive impact on improving the vibration resistance of SDCM piles. In contrast, changes in porosity have a negligible effect on the ability to resist vertical vibrations of SDCM piles.

Enhancing Organizational Performance: Can Innovative Millennial Entrepreneurship and Business Continuity Take on A Mediating Role?

Facing business challenges requires creative ideas that can push into the realm of innovation. Innovation, which is widely held by the millennial generation, is advantageous for companies because this generation is good at developing ideas. However, the phenomenon is that 67% of creative media businesses in 2021 declined in revenue. In connection with these main obstacles, the purpose of this study is to identify constructs that can mediate the role of Relational Capital (RC) in organizational performance (OP). To address the research objective, this study concentrates on the creative media industry, utilizing a sample of 163 respondents. The data were analyzed using Structural Equation Modeling (SEM) through the AMOS software. The results reveal that RC does not have a significant impact on OP.This research examines the role of Innovative Millennial Entrepreneurship (IME) and Business Continuity (BC) in mediating RC to OP. This study empirically proved that RC has no significant effect on OP, but IME and BC can increase RC to OP, with a total effect of 1.487 for IME and 0.509 for BC. Based on this result, it is empirically proven that IME and BC fully mediate the role of RC in CP. This is a contribution to the theoretical domain of dynamic capacity theory.

THE WHY AND WHAT OF AI DEPLOYMENT AND INNOVATION IN COMPANIES — RESULTS AND LEARNINGS FROM A SYSTEMATIC LITERATURE RESEARCH ENLIGHTENED BY THE CAPABILITY THEORY

Despite soaring interest in Artificial Intelligence (AI), only one-tenth of companies have reported tangible business results. We conducted a Systematic Literature Research on peer-reviewed reports to establish an updated status and baseline of AI deployment for research and companies. We analysed selected peer-reviewed articles for deployment objectives, approaches, results, and learnings. This research confirms that AI is still at the early stages of deployment and innovation in companies. Deploying AI successfully represents a management — rather than a technology — challenge. It requires more cognisance, innovation, learning, and effort than generally thought. Through the results and a novel conceptual framework, this research increases the knowledge and emphasises the importance of the pre-deployment from theoretical and practical viewpoints. The Sensing stage of the Dynamic Capability theory aligns well with the developed pre-deployment concept. We propose several research topics to increase the knowledge and theoretical understanding of deploying AI cognisably for business and stakeholder benefits.

Two-Band Electronic Reconstruction Induced via Correlation and CDW Order Effects

The emergence of a charge density wave (CDW) in transition-metal dichalcogenides opens up a route to charge order, followed by superconductivity at low temperatures. A key question here concerns how many particle electron–electron interations govern the low-energy electronic structure in the normal and CDW states. Using dynamical mean-field theory, we explore the many-body properties of an extended, two-band Hubbard model applicable to 2H-TaSe2. We reveal the electronic structure reconstruction in the normal and CDW states driven by two-band dynamical correlations. Our results demonstrate a remarkable renormalization of the Ta-5d bands crossing the Fermi level, showing a continuous reduction in the CDW gap up to an incomplete gapping, followed by a CDW to a CDW–Mott phase transition pertinent to strongly correlated transition-metal dichalcogenides.

Fate of the Mollow triplet in strongly coupled atomic arrays

Subwavelength arrays of quantum two-level emitters have emerged as an interesting platform displaying prominent collective effects that can be harnessed for applications. Here, we study such arrays under strong coherent driving, realizing an open quantum many-body problem in a strongly nonlinear regime. For this we introduce an approach to this problem in terms of a dynamical mean-field theory, paving the way for further studies. We show that the spectrum of scattered light, characterized by the famous Mollow triplet for a single atom, develops a characteristic line shape with flat sidebands determined by dipolar interactions and relevant for experiments. Remarkably, this is to some extent independent of the specific geometry, but is sensitive to the ordered arrangement of the atoms. This line shape therefore characterizes atomic arrays and distinguishes them from disordered ensembles and noninteracting emitters. Published by the American Physical Society 2024

Respective Roles of Electron-Phonon and Electron-Electron Interactions in the Transport and Quasiparticle Properties of SrVO_{3}.

The spectral and transport properties of strongly correlated metals, such as SrVO_{3} (SVO), are widely attributed to electron-electron (e-e) interactions, with lattice vibrations (phonons) playing a secondary role. Here, using first-principles electron-phonon (e-ph) and dynamical mean field theory calculations, we show that e-ph interactions play an essential role in SVO: they govern the electron scattering and resistivity in a wide temperature range down to 30K, and induce an experimentally observed kink in the spectral function. In contrast, the e-e interactions control quasiparticle renormalization and low temperature transport, and enhance the e-ph coupling. We clarify the origin of the near T^{2} temperature dependence of the resistivity by analyzing the e-e and e-ph limited transport regimes. Our work disentangles the electronic and lattice degrees of freedom in a prototypical correlated metal, revealing the dominant role of e-ph interactions in SVO.

A dynamical optimal control theory and cost-effectiveness analyses of the HBV and HIV/AIDS co-infection model.

Studies have shown that the co-infection of Human Immunodeficiency Virus (HIV) and Hepatitis B Virus (HBV) poses a major threat to the public health due to their combined negative impacts on health and increased risk of complications. Even though, some scholars formulated and analyzed the HBV and HIV co-infection model they did not consider the compartment that contains protected individuals against both HBV and HIV infections. They incorporated the optimal control theory and cost-effectiveness analysis simultaneously. With this in mind, we are motivated to formulate and analyze the HBV and HIV co-infection model, considering the protected group and incorporating optimal control theory and cost-effectiveness. In this study, we have theoretically computed all of the models disease-free equilibrium points, all the models effective reproduction numbers and unique endemic equilibrium points. The two sub-models disease-free equilibrium points are locally as well as globally asymptotically stable whenever their associated effective reproduction numbers are less than one. We reformulated the optimal control problem by incorporating five time-dependent control measures and conducted its theoretical analysis by utilizing the Pontryagin's maximum principle. Using the fourth order Runge-Kutta numerical method and MATLAB ODE45, we performed the numerical simulations with various combinations of control efforts to verify the theoretical results and investigate the impacts of the suggested protection and treatment control strategies for both the HBV and HIV diseases. Also, we carried out a cost-effectiveness analysis of the proposed control strategies. Eventually, we compared our model results with other researcher similar model results whenever cost-effectiveness analysis is not carried out the findings of this particular study suggest that implementing each of the proposed control strategies simultaneously has a high potential to reduce and control the spread of HBV and HIV co-infections in the community. According to the cost-effectiveness analysis, implementing the HBV treatment and the HIV and HBV co-infection treatment measures has a high potential effect on reducing and controlling the HBV and HIV co-infection transmission problem in the community.

Posttraumatic Growth: The Role of Health and Financial Difficulties During a Pandemic.

Trauma can have a range of effects on individuals over time, including the potential for positive changes in favorable outcomes commonly referred to as posttraumatic growth. The posttraumatic growth literature has been criticized for various methodological limitations and has largely neglected the exploration of factors that may strengthen or weaken posttraumatic growth trajectories. The present study contributes to this literature by investigating trajectories of five dimensions of posttraumatic growth during the COVID-19 pandemic and the moderating effects of health and financial difficulties on these trajectories. Longitudinal data were collected monthly between July 2020 and December 2022 from a sample of employed adults in Germany, involving N = 1678 participants over 30 time points (Nobservations = 29,552). Results suggest that certain dimensions of posttraumatic growth showed significant increases (i.e., relationships) or decreases (i.e., spirituality and possibilities) over time and that trajectories of three dimensions (i.e., relationships, appreciation, and strength) demonstrated distinctive patterns of interaction with health and financial difficulties. Findings are discussed in the context of the pandemic as well as dynamic theories of personality and identity, with implications for advancing posttraumatic growth theory and research.

Nutation-orbit resonances: The origin of the chaotic rotation of Hyperion and the barrel instability

While numerous planetary and asteroid satellites show evidence for non-trivial rotation states, none are as emblematic as Hyperion, which has long been held as the most striking example of chaotic spin-orbit evolution in the Solar System. Nevertheless, an analytically tractable theory of the full 3D spin-orbit dynamics of Hyperion has not been developed. We derive the Hamiltonian for a spinning axisymmetric satellite in the gravitational potential of a planet without assuming planar or principal axis rotation and without averaging over the spin period. Using this model, we demonstrate the emergence of resonances between the nutation and orbital frequencies that act as the primary drivers of the spin dynamics. This analysis reveals that, contrary to long-held belief, Hyperion is not tumbling chaotically. Instead, it lies near or in a nutation-orbit resonance that is first-order in eccentricity, allowing it to rotate quasi-regularly. The most reliable observations are consistent with either nonchaotic motion or chaos that is orders of magnitude smaller than originally claimed. A separate phenomenon, the so-called barrel instability, is shown to be related to a different set of nutation-orbit resonances that generalize the planar spin-orbit resonances. Finally, we show that changes in spin states over long timescales are best understood by considering chaotic diffusion of quasi-conserved quantities.

On the Existence of Extreme Coherent Distributions with No Atoms

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Dynamic wheel-rail interaction of a train crossing a turnout under traction/braking behaviour and research on rail wear of the turnout

In order to study the dynamic behaviour of a vehicle passing through turnouts under traction and braking conditions, as well as its influence on the wear of turnout rails, a high-speed vehicle-turnout rigid-flexible coupling dynamic model is established based on the coupling dynamic theory of vehicle and turnout, using China’s No. 18 high-speed turnout and CRH380 high-speed EMU as prototypes. The model is used to analyse wheel-rail creep characteristics, wheel-rail contact mechanics, and wheel-rail wear under traction and braking conditions. The results indicate that when a high-speed train passes through a turnout under traction or braking conditions, the longitudinal creepage of the wheel-rail will change due to the rotative speed difference generated by traction or braking. Furthermore, due to the existence of the lead curve, the longitudinal creep rate of the wheel-rail becomes even more complex when passing through the turnout in the diverging route. The calculations reveal that the traction behaviour of the train leads to a significant increase in wear at the front of the switch rail and nose rail, while the wear number of the switch rail in the heel of the frog after 6m increases significantly under braking conditions. The different impact characteristics of vehicle traction and braking conditions on turnout rail wear obtained in this study can provide guidance for optimizing and grinding the profiles of turnout rails at the throat of railway stations.

Information consistency and inhibition impact on diffusion in networks

This paper introduces the Principal-Agent mechanism to study the diffusion of information in complex networks. Hot list information is defined as principal information, information that is homogeneous with hot list information is defined as homogeneous agent information, and information that is heterogeneous with hot list information is defined as heterogeneous agent information. The theory of diffusion dynamics is used to study the phenomenon that homogeneous information promotes each other and heterogeneous information inhibits each other in the process of competitive diffusion of network information. Based on the traditional SIR model, this paper introduces the Principal-Agent mechanism, establishes the PA_SIR diffusion model and studies the mutual influence of information in the process of competitive diffusion of multiple information. The research shows that in the process of competitive diffusion of multiple information, principal information has a positive incentive effect on homogeneous agent information through people’s interest orientation, herd mentality and topic public opinion and has a negative incentive effect on heterogeneous agent information. Therefore, if you want your published information to attract more attention, the best release time is when homogeneous information is on the hot search list, which will help to attract people’s attention more quickly.