Dynamical Theory Research Articles

An explicit multilevel power turbulent wall function based on the de-thresholding Douglas–Peucker algorithm

Wall functions are extensively applied in engineering simulations with turbulence. They facilitate a significant increase in the scale of the grids next to the wall, which in turn reduces the total number of grids needed. This optimization enhances computational efficiency, making the simulation process more effective and streamlined. However, the current commonly used wall functions, such as the Spalding wall function, are an implicit expression that needs to be solved iteratively, which affects the computational efficiency, and the multilayer segmented wall function is not smoothly articulated, which affects the fidelity. In this study, based on flat plate direct numerical simulation (DNS) data, combined with structural ensemble dynamics theory, the de-thresholding Douglas–Peucker algorithm is introduced to construct an explicit wall function expression in the form of multilevel power exponential concatenated multiplication. The comparison of the new wall function against DNS data reveals that it demonstrates superior fitting accuracy in contrast to the traditional ones, and eliminates the need for manual calibration, reduces subjective influence, and enhances reliability. The numerical simulation outcomes for the flat plate boundary layer and a series of airfoils showcase the new wall function's exceptional accuracy, which not only meets but also surpasses the demanding standards of engineering practice.

Особливості правового статусу банків як юридичних осіб

The article describes the peculiarities of banks’ legal personality and considers approaches to the universal and special legal capacity of banks as legal entities. It also argues the expediency of using the dynamic theory for determining banks’ legal capacity and the application of special legal ability of banks. The analysis provided in the article is based on the approach according to which the legal ability of legal entities that in the future must obtain permission (permit, license, registration or authorization) for the right to conduct certain types of activities arises in two stages. First, a legal entity receives a minimum universal civil legal ability from the moment of its state registration to the extent necessary for its functioning as a legal entity. The second stage is obtaining a banking license by a bank, which is actually obtaining a special legal capacity. The article analyses all banks’ services (banking services, other financial services, as well as non-financial services provided by the banks), the provision of which requires a special legal capacity. It is argued that special legal ability of the bank provides for the ability to have rights and bear responsibilities necessary for the provision of banking services. A banking service on raising funds and refundable investment metals, in contrast to such raising by other financial institutions, should be considered raising to a bank account. Banking services on opening bank accounts provides for a unique feature of banks - their systemic technological nature to ensure monetary settlements between banks and bank clients. It is suggested to introduce in the legislation the provision that not only the opening of bank accounts should be considered a banking service, but also the provision of settlements between parties which have bank accounts. It is argued that the bank is a unique universal financial institution not so much because of the list of services itself, most of which can be provided by other financial institutions, but because it can provide these services in combination with other services (in complex way). It is indicated that the peculiarity of the legal capacity of the bank as a legal entity lies in introducing a two-tier governance system only with a collegial executive body and tighter requirements in regard to the quality of academic and professional background of members of such governing bodies.

A novel investigation of the influence of vaccination on pneumonia disease

In the entire world, pneumonia is one of the leading causes of death, which is particularly dangerous for young children (those under five years old) and the elderly (those over 65). A deterministic susceptible, vaccinated, exposed, infected, and recovered (SVEIR) model is used in this work to mathematically study the dynamics of pneumonia disease and examine stability analysis, basic reproduction numbers, and equilibrium points of dynamical systems theory models. Spatial equilibria are studied to model disease-free equilibria that are locally asymptotic stable. Numerical simulations of the model have been carried out using MATLAB21. The SVEIR flow and its variables for different parameter sets have been studied through numerical simulations. The solution to the issue is provided through the use of illustrated and explicated results. According to research findings, if vaccination rates rise over the necessary vaccination ratio, the sickness will finally vanish from the community.

Promoting sustainable development goals through generative artificial intelligence in the digital supply chain: Insights from Chinese tourism SMEs

AbstractInterdisciplinary advancements, such as generative artificial intelligence (AI) and digital supply chains, can significantly contribute to achieving sustainable development goals (SDGs), particularly within tourism. This paper illuminates how it works well, focusing on the underexplored area of Environmental, Social, and Governance (ESG) performance within small and medium‐sized tourism enterprises (SMEs) in China. Through a survey of 429 international SMEs, we apply the Resource‐Based View and Dynamic Capabilities Theory to investigate how generative AI, such as ChatGPT, in digital supply chains can enhance innovation, collaboration, and, ultimately, ESG performance. The empirical findings underscore the pivotal role of generative AI in augmenting ESG performance via bolstering innovation and collaboration within digital supply chains. Additionally, the moderating effect of customer involvement positively influences the relationship between the digital supply chain and ESG performance. By demonstrating these relations, our study contributes to theoretical and practical efforts toward sustainable tourism and the broader achievement of the SDGs.

Role of Nanoparticle Size in the Photocatalytic Degradation of Pollutants

Purpose: The aim of the study was to assess the role of nanoparticle size in the photocatalytic degradation of pollutants. Methodology: This study adopted a desk methodology. A desk study research design is commonly known as secondary data collection. This is basically collecting data from existing resources preferably because of its low cost advantage as compared to a field research. Our current study looked into already published studies and reports as the data was easily accessed through online journals and libraries. Findings: The study indicated that smaller nanoparticles exhibit a higher surface area-to-volume ratio, providing more active sites for pollutant interaction and adsorption, which enhances the overall degradation process. Additionally, smaller nanoparticles tend to have higher charge carrier mobility and reduced recombination rates of electron-hole pairs, further improving photocatalytic activity. This increased efficiency is critical in environmental applications, as it allows for the effective breakdown of various contaminants, including dyes, pesticides, and pharmaceuticals, at lower catalyst loadings and shorter reaction times. The optimization of nanoparticle size, therefore, plays a crucial role in developing advanced photocatalytic systems for environmental remediation. Implications to Theory, Practice and Policy: Optical absorption theory, surface area and reaction kinetics theory and charge carrier dynamics theory may be used to anchor future studies on assessing the role of nanoparticle size in the photocatalytic degradation of pollutants. Develop robust methodologies for synthesizing nanoparticles with precise control over size distribution. Establish standardized protocols for evaluating the performance and safety of nanoparticle-based photocatalytic materials. This includes setting benchmarks for degradation efficiency, durability, and potential environmental impacts.

Quenched Pair Breaking by Interlayer Correlations as a Key to Superconductivity in La_{3}Ni_{2}O_{7}.

The recent discovery of superconductivity in La_{3}Ni_{2}O_{7} with T_{c}≃80 K under high pressure opens up a new route to high-T_{c} superconductivity. This material realizes a bilayer square lattice model featuring a strong interlayer hybridization unlike many unconventional superconductors. A key question in this regard concerns how electronic correlations driven by the interlayer hybridization affect the low-energy electronic structure and the concomitant superconductivity. Here, we demonstrate using a cluster dynamical mean-field theory that the interlayer electronic correlations (IECs) induce a Lifshitz transition resulting in a change of Fermi surface topology. By solving an appropriate gap equation, we further show that the leading pairing instability, s± wave, is enhanced by the IECs. The underlying mechanism is the quenching of a strong ferromagnetic channel, resulting from the Lifshitz transition driven by the IECs. Based on this picture, we provide a possible reason of why superconductivity emerges only under high pressure.

Anisotropy-driven magnetic phase transitions in SU(4)-symmetric Fermi gas in three-dimensional optical lattices

Abstract We study SU(4)-symmetric ultracold fermionic mixture in the cubic optical lattice with the variable tunneling amplitude along one particular crystallographic axis in the crossover region from the two- to three-dimensional spatial geometry. To theoretically analyze emerging magnetic phases and physical observables, we describe the system in the framework of the Fermi-Hubbard model and apply dynamical mean-field theory. We show that in two limiting cases of anisotropy there are two phases with different antiferromagnetic orderings in the zero temperature limit and determine a region of their coexistence. We also study the stability regions of different magnetically-ordered states and density profiles of the gas in the harmonic optical trap.

The effects of digital transformation on exploitation and exploration: does technological diversity matter?

PurposeFor survival and prosperity, enterprises need to simultaneously engage in exploitation and exploration. Digital transformation is of great significance to enterprise innovation. However, the impacts of digital transformation on exploitation and exploration remain unclear. Moreover, the impacts of technological diversity on the relationships between digital transformation and exploitation and exploration are also unknown.Design/methodology/approachBased on an integrated perspective of dynamic capability theory and organizational inertia theory and using data from Chinese listed enterprises from 2007 to 2020, this study clarifies the effects of digital transformation on exploitation and exploration and assesses the moderating effect of technological diversity.FindingsThe results show that digital transformation improves exploitation, but negatively impacts exploration. Technological diversity mitigates the negative effect of digital transformation on exploration, but the moderating effect on the relationship between digital transformation and exploitation is not significant.Originality/valueThis study contributes to the existing literature on the digital paradox and provides guidance for enterprises to clarify the direction of digital transformation.

Effects of dynamic diffraction in coherent X-ray radiation from a beam of relativistic electrons in a periodic layered medium with three layers in a period

The possibilities of manifestation of dynamic diffraction effects in coherent X-ray radiation (CXR) of relativistic electrons in a periodic layered medium (PLM) with three different layers in a period are being investigated. A dynamic theory of CXR of relativistic electrons has been developed for the case of such a target. The corresponding formulas for the spectral-angular characteristics of parametric X-ray radiation (PXR) and diffracted transition radiation (DTR) are obtained and studied. The influence of asymmetric diffraction on the spectral-angular densities of PXR and DTR is shown. A striking effect of anomalous photoabsorption in PXR in a layered target, similar to the Bormann effect in a single crystal, is predicted.

MILESTONES IN THE DEVELOPMENT OF ORGANIZATIONAL MODELS BASED ON THE THEORY OF SPIRAL DYNAMICS

The article examines the milestones of the development of the business environment through the prism of industrial revolutions and the theory of spiral dynamics of organizational development. The past influences the present. The present shapes the future. The world is a complex, interconnected whole that is difficult to represent and understand, especially regarding complex socio-economic processes and organizational systems, including enterprises. The first radical change began precisely with the agrarian revolution when people domesticated animals as a basis for the transition from gathering to agriculture. After the agrarian revolution, radical industrial changes began in the 18th century. The first industrial revolution (from the 1760s to the 1840s) - the invention of the steam engine and the construction of railways. The second industrial revolution (the end of the 19th and the beginning of the 20th century) - the emergence of mass production thanks to the invention of electricity and the introduction of the conveyor. The third industrial revolution, from the 1960s, - was the emergence of semiconductors and their use in large electronic computing machines, personal computers, and the Internet. The fourth industrial revolution began at the beginning of the 21st century and is characterized by the emergence of "smart enterprises". The content and essential components of these periods imposed and imposed their understanding on the development of organizational models and the way of interaction between stakeholders and the economic entities themselves, which arose at the later stages of development and are developing under the influence of global business trends. Deepening the understanding of the nature of modern approaches in management aimed at the development of organizational systems allows turning to the past and investigating issues of organizational models on the way of the history of human development based on the theory of spiral dynamics (Don et al.), which is based on a dynamic model of human development and evolution of her consciousness, change of fundamental values. So, from the standpoint of the concept of systemic perfection of a business organization, based on the theory of spiral dynamics, its consideration can be started in the system-wide understanding of the system state, which corresponds to a greater extent to the content of perfection - from the orange stage and more/less corresponds to the current trends of the fourth industrial revolution. A significant strategic gap occurs based on the mismatch between the stage of development according to the milestones of industrial revolutions and the organization's current state in relation to the theory of spiral dynamics. For example, a red organization that functions in the fourth industrial revolution era. Management of changes in paradigms of thinking is the art of management.

Psychometric network analysis in rehabilitation research: A methodological demonstration in depression symptoms of veterans and service members at 1 and 2 years after traumatic brain injury.

Psychometric network analysis (PNA) is an application of dynamic systems theory that can inform measurement of complex rehabilitation phenomena such as depressive symptom patterns in veterans and service members (V/SMs) after traumatic brain injury (TBI). This study applied PNA to the Patient Health Questionnaire-9 (PHQ-9), a common measure of depressive symptoms, in a sample of V/SMs with TBI at Years 1 and 2 (Y1-2) postinjury. A sample of 808 V/SMs with TBI participated, 594 contributing PHQ-9 data at Y1 and 585 at Y2. Participants were recruited while or after receiving inpatient postacute rehabilitation from one of five Veterans Affairs Polytrauma Rehabilitation Centers. The networks were stable and invariant over time. At both times, network structure revealed the cardinal depressive symptom "feeling down, depressed, or hopeless," as evidenced by its strength centrality. In the Y1 network, the suicidal ideation node was connected exclusively to the network through the guilt node, and in the Y2 network, the suicidal ideation node formed a second connection through the low mood node. The guilt node was the second most influential node at Y1 but was replaced by anhedonia node at Y2. This study demonstrated the potential of PNA in rehabilitation research and identified the primacy of feeling down, depressed, and hopeless after TBI at both Y1 and Y2, with guilt being the second most influential symptom at Y1, but replaced by anhedonia at Y2, providing supportive evidence that the relationships among depressive symptoms after TBI are dynamic over time. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Unveiling the complexity of L2 learners’ emotions and emotion regulation: A retrodictive qualitative modeling study

AbstractSecond/foreign language (L2) learners often go through a gamut of conflicting experiences embedded within their emotional system, which can be managed through emotion regulation (ER). Motivated by complex dynamic systems theory (CDST), this qualitative study aimed to explore the signature dynamics of positive and negative emotions among six Iranian adolescent English language learners. Additionally, the study investigated how learners manage their emotions in the L2 classroom. Using the CDST as its main theoretical framework and retrodictive qualitative modeling as its main methodology, the current investigation revealed that the learners’ emotional systems were mediated by internal and external contexts, as well as dynamicity. It was further discovered that ER strategies were driven by multiple simultaneous factors influencing emotional systems and the adaptability of those systems to new situations. In the end, we discuss how policymakers, teachers, and researchers can adopt the findings to provide some well‐needed support for classroom‐based L2 learners.

Early-life dispersal traits of coastal fishes: an extensive database combining observations and growth models

Abstract. Early-life stages play a key role in the dynamics of bipartite life cycle marine fish populations. Difficult to monitor, observations of these stages are often scattered in space and time. While Mediterranean coastlines have often been surveyed, no effort has been made to assemble historical observations. Here we build an exhaustive compilation of dispersal traits for coastal fish species, considering in situ observations and growth models (Di Stefano et al., 2023; https://doi.org/10.17882/91148). Our database contains over 110 000 entries collected from 1993 to 2021 in various subregions. All observations are harmonized to provide information on dates and geolocations of both spawning and settlement, along with pelagic larval durations. When applicable, missing data and associated confidence intervals are reconstructed from dynamic energy budget theory. Statistical analyses allow traits’ variability to be revisited and sampling biases to be revealed across taxa, space and time, hence providing recommendations for future studies and sampling. Comparison of observed and modelled entries provides suggestions to improve the feed of observations into models. Overall, this extensive database is a crucial step to investigate how marine fish populations respond to global changes across environmental gradients.

Simulation and Optimization of Hole Transport Layer Performance of Lead‐Free Perovskite Solar Cells

AbstractThis article employs a combined approach using SCAPS and MS software to screen the cell structure combinations of various cell materials such as MASnI3, FASnI3, TiO2, C60, spiro‐OMeTAD, PTAA, CuI, CuSCN, Cu2O, and NiO. The structure of lead‐free perovskite solar cells (PSCs): FTO/TiO2/MASnI3/Cu2O/Au is identified as having the best cell performance. Based on Molecular Dynamics theory, in combination with physical experimental preparation and characterization results, it is found that Cu2O thin films treated with annealing at 388 °C, as the hole transport layer material, can significantly enhance the performance of PSCs. This optimization led to power conversion efficiency (PCE) and fill factor (FF) performance indicators reaching 29.2% and 87.32%, achieving excellent cell performance.

Antiferromagnetic and spin spiral correlations in the doped two-dimensional Hubbard model: Gauge symmetry, Ward identities, and dynamical mean-field theory analysis

Antiferromagnetic and spin spiral correlations in the doped two-dimensional Hubbard model: Gauge symmetry, Ward identities, and dynamical mean-field theory analysis

Effect of Data Integration Techniques on Operational Efficiency in Manufacturing Industries in Iran

Purpose: The aim of the study was to assess the effect of data integration techniques on operational efficiency in manufacturing industries in Iran. Materials and Methods: This study adopted a desk methodology. A desk study research design is commonly known as secondary data collection. This is basically collecting data from existing resources preferably because of its low cost advantage as compared to a field research. Our current study looked into already published studies and reports as the data was easily accessed through online journals and libraries. Findings: The study found that by seamlessly amalgamating data from disparate sources across production lines, supply chains, and customer feedback systems, manufacturers have been able to streamline processes, optimize resource allocation, and achieve significant cost savings. For instance, real-time data integration facilitates timely decision-making, allowing for adaptive production planning and inventory management. Furthermore, the integration of advanced analytics and machine learning algorithms has enabled predictive maintenance strategies, reducing downtime and enhancing overall equipment effectiveness (OEE). These technological advancements not only bolster operational efficiency but also foster innovation, as companies leverage integrated data insights to drive continuous improvement initiatives and meet evolving consumer demands. Implications to Theory, Practice and Policy: Resource-based view (RBV), technology acceptance model and dynamic capabilities theory may be used to anchor future studies on assessing the effect of data integration techniques on operational efficiency in manufacturing industries in Iran. Manufacturing firms should prioritize strategic implementation plans for data integration technologies to ensure that investments in IoT, AI, ETL, data warehousing, data virtualization, and APIs are aligned with their overall business objectives. Policymakers should provide incentives and support for the adoption of advanced data integration technologies in the manufacturing sector.

An analysis of the interaction between surface and basal crevasses in ice shelves

Abstract. The prescription of a simple and robust parameterization for calving is one of the most significant open problems in ice sheet modelling. One common approach to the modelling of crevasse propagation in calving in ice shelves is to view crevasse growth as an example of linear elastic fracture mechanics. Prior work has, however, focused on highly idealized crack geometries, with a single fracture incised into a parallel-sided slab of ice. In this paper, we study how fractures growing from opposite sides of such an ice slab interact with each other, focusing on different simple crack arrangements: we consider either perfectly aligned cracks or periodic arrays of laterally offset cracks. We visualize the dynamics of crack growth using simple tools from dynamical systems theory and find that aligned cracks tend to impede each other's growth due to the torques generated by normal stresses on the crack faces, while periodically offset cracks facilitate simultaneous growth of bottom and top cracks. For periodic cracks, the presence of multiple cracks on one side of the ice slab, however, also generates torques that slow crack growth, with widely spaced cracks favouring calving at lower extensional stresses than closely spaced cracks.

Revisiting the ‘magic condition’ on the basis of the Takagi–Taupin theory

A numerical framework based on the integral solution of the Takagi–Taupin equations has been developed for cylindrically bent Laue crystals. On the basis of this framework, diffraction geometries that satisfy the `magic condition' have been studied from the perspective of dynamical theory. The numerical findings indicate that, in certain diffraction geometries, the focusing behaviour of cylindrically bent Laue crystals will be notably influenced by dynamical effects and the foci of different energies will not converge as predicted by the `magic condition', which is derived from geometric optics theory. These dynamical effects are further explained through a direct numerical analysis of the influence function.

Sufficient conditions on the continuous spectrum for ergodic Schrödinger operators

We investigate the spectral types of families of discrete one-dimensional Schrödinger operators {Hω}ω∈Ω , where each H ω has a potential function V ω (n) = f(T n ω) for n∈Z , T is an ergodic homeomorphism on a compact space Ω and f:Ω→R is a continuous function. The main analytical tool of the paper is Gordon’s lemma, of which we provide a complete proof. We demonstrate that a generic operator Hω∈{Hω}ω∈Ω has purely continuous spectrum if {Tnα}n≥0 is dense in Ω for a certain α ∈ Ω. Furthermore, we extend this result to the case where {Ω, T} satisfies topological repetition property, a concept introduced by Boshernitzan and Damanik (2008, []). Theorems presented in this paper weaken the hypotheses of previous research and enable us to reach the same conclusion as those authors. Our paper presents a comprehensive study of the topological and metric repetition properties, highlighting their binding role between the theory of dynamical systems and spectral theory. We also discuss the implications of these properties on the qualitative description of specific physical systems.

Decomposing Imaginary-Time Feynman Diagrams Using Separable Basis Functions: Anderson Impurity Model Strong-Coupling Expansion

We present a deterministic algorithm for the efficient evaluation of imaginary-time diagrams based on the recently introduced discrete Lehmann representation (DLR) of imaginary-time Green’s functions. In addition to the efficient discretization of diagrammatic integrals afforded by its approximation properties, the DLR basis is separable in imaginary-time, allowing us to decompose diagrams into linear combinations of nested sequences of one-dimensional products and convolutions. Focusing on the strong-coupling bold-line expansion of generalized Anderson impurity models, we show that our strategy reduces the computational complexity of evaluating an Mth-order diagram at inverse temperature β and spectral width ωmax from O((βωmax)2M−1) for a direct quadrature to O(M(log(βωmax))M+1), with controllable high-order accuracy. We benchmark our algorithm using third-order expansions for multiband impurity problems with off-diagonal hybridization and spin-orbit coupling, presenting comparisons with exact diagonalization and quantum Monte Carlo approaches. In particular, we perform a self-consistent dynamical mean-field theory calculation for a three-band Hubbard model with strong spin-orbit coupling representing a minimal model of Ca2RuO4, demonstrating the promise of the method for modeling realistic strongly correlated multiband materials. For both strong and weak coupling expansions of low and intermediate order, in which diagrams can be enumerated, our method provides an efficient, straightforward, and robust blackbox evaluation procedure. In this sense, it fills a gap between diagrammatic approximations of the lowest order, which are simple and inexpensive but inaccurate, and those based on Monte Carlo sampling of high-order diagrams. Published by the American Physical Society 2024