System In Order Research Articles

Multistable dynamics and chaos in a system consisting of an inertial neuron coupled to a van der Pol oscillator

Abstract We consider a dynamical system consisting of a van der Pol oscillator linearly coupled to an inertial neuron with two wells potential. Analytical studies are conducted focusing on the energy computation, the dissipation and symmetry, as well as the determination and characterization of the equilibrium points. We define the parameter ranges related to different types of oscillations in the coupled system in order to have an overall idea of the nature of the attractors (hidden or self-excited) that may exist. We apply numerical analysis techniques (2-parameter diagrams, bifurcation analysis, phase portraits, basins of attractions, etc) in accordance with the previous operating range in order to shed light on the plethora of competing dynamics of the model and possible forms of strange attractors as well. Another salient point of this work is the coexistence between five self-excited attractors (limit cycle and chaos) with a hidden attractor (limit cycle). We also examine the impact of symmetry breaking on the system response. An appropriate analog simulator of the coupled system is designed and simulated in PSpice in order to check the results reported during the theoretical analyses. We believe that the results of the present work complement and enrich previously published ones concerning the dynamics of a system composed of a van der pol oscillator coupled to a (non-oscillating) double-well oscillator.

Schouten-Codazzi Gravity

Abstract We propose a new phenomenological second order gravity theory to be denoted as ''Schouten-Codazzi' Gravity'' (SCG), as it is based on Schouten and Codazzi tensors. The theory is related, but is clearly distinct from Cotton Gravity. By assuming as source the energy momentum of General Relativity, we form a second order system with its geometric sector given by the sum of the Schouten tensor and a generic second order symmetric tensor complying with the following properties: (i) it must satisfy the Codazzi differential condition and (ii) it must be concomitant with the invariant characterization based on the algebraic structure of curvature tensors for specific spacetimes or classes of spacetimes. We derive and briefly discuss the properties of SCG solutions for static spherical symmetry (vacuum and perfect fluid), FLRW models and spherical dust fluids. While we do recognize that SCG is ``work in progress'' in an incipient stage that still requires significant theoretical development, we believe that the theory provides valuable guidelines in the search for alternatives to General Relativity

Patterns of eConsult use: A retrospective analysis of usage comparing two models deployed at an academic medical center

Introduction Electronic consultations (eConsults) have been implemented by numerous academic medical centers (AMCs) to improve communication and address access to specialty care. As these models proliferate, we must understand their comparative benefit and use in various settings. Methods This retrospective, descriptive analysis compares eConsult utilization trends at an AMC that has deployed an internal effort and an external pivot. Relevant metrics are presented using counts and proportions or median and range where appropriate. Results The internal AMC program demonstrated sustained growth from years 1 through 6, while the external pivot demonstrated considerable growth in year 1, followed by a steady decline in subsequent years. Endocrinology generated the highest number of eConsult orders in both programs (AMC 21%, external pivot 16%). Conversion rates to in-person visits were higher in the external pivot (22%) than in the internal AMC program (14%). Median response time across all specialties was faster (17 hours) for the AMC program than the external pivot (23 hours). The median number of eConsults ordered by any single primary care provider was 3 in both programs. The percentage of providers using the eConsult ordering system only once was approximately 30% in both programs. eConsults were primarily ordered by physicians (68%) at the AMC and physician assistants (40%) in the external pivot. Discussion The current study highlights similarities and differences between internal and external eConsult programs that can inform future “right-sizing” of care according to patient needs while promoting local care delivery and improving efficiencies at the AMC.

Intelligent-based approach for parameters identification and control of fractional order systems

The optimization algorithms for identification and control processes take more and more place in the industrial domain. However, determining a control law for fractional systems remains challenging for researchers today. This paper presents a simple method for using a fractional PID (FOPID) corrector to regulate a class of fractional systems that show a stable step response. The procedure is based on an algorithmic identification to assimilate the fractional system into a simple model. Optimization methods were used. Using techniques like Particle Swarm Optimization (PSO), Genetic Algorithm (GA), Artificial Bee Colony (ABC), and Ant Colony Optimization (ACO) to ascertain the parameters of the basic model, a first-order system with delay. Then, the FOPID controller will be calculated using Ziegler–Nichols methods and optimization algorithms to stabilize the real process. Better performance Overshoot and Settling time as well as minimal Energy control effort are benefits of the proposed design. To confirm that the fractional regulator is robust which is optimized by the best-chosen method (PSO), the parameters of the chosen process will be randomly varied. Through two numerical simulations, the efficiency of the suggested method has been confirmed.

SOCIAL AND PSYCHOLOGICAL ASPECTS OF FORMING AN EFFECTIVE INNOVATIVE TEAM

This article highlights issues related to the social and psychological foundations of the formation of a team capable of working effectively and responding to modern challenges of the market environment. It was determined that such bases are the individual motives of the members of the labor team, namely their personal beliefs regarding the expediency of performing professional tasks. It is established that they are formed at the early stages of the socialization of the individual under the influence of education, upbringing, norms of social morality and are corrected during his subsequent working life. It has been found that motives can be more stable than incentives, which can cause an undesirable final result of the enterprise's activity. With this in mind, the task of institutional management should be the creation of an effective motivational system aimed at strengthening the role of incentives in the structure of employee motivation for professional development, professional development, creativity, creativity and initiative. The article provides recommendations on directions for adjusting the national management system in order to create an effective innovative team. In particular, to improve the work of the team and the final efficiency of the enterprise, it is recommended to create an effective system of labor incentives through the introduction of elements of foreign management models. The proposed elements make it possible to create an effective model of personnel motivation management, as they are aimed at strengthening the personal motives of employees to protect their own professional interests and dignity, use the opportunity for self-development and self-realization, involvement in the process of enterprise management and decision-making, evaluation of one's own labor contribution and recognition of the obtained results, adjustment constructive business relations in the team. It was determined that these innovations should become the basis for further improvement of the motivation of employees in the domestic management system, since each branch and field of activity has its own characteristics, taking into account the possibility of their further adjustment.

Controllability of Impulsive Damped Fractional Order Systems Involving State Dependent Delay

In this article, the concept of controllability on fractional order impulsive systems involving state dependent delay and damping behavior is analysed by utilizing Caputo fractional derivative. The main motivation is to derive the sufficient conditions for the controllability of the considered systems. Based on the Laplace transform and inverse Laplace transform, the solution of fractional-order dynamical systems are obtained. The results are established by utilizing basic ideas of fractional calculus, Mittag-Leffler function and Banach fixed point theorem. Finally, an application is provided to illustrate the derived result.

An Investigation Into To The Use Of Artificial Intelligence In The Indian Tax System

Indian taxation is main source of public finance in developing economy. The Indian tax system has long been plagued by issues including tax evasion and ineffective administration. Tax administration systems must constantly be designed to reduce errors and speed up decision-making. The Indian tax system is beset by a shortage of workers to do labor-intensive duties including data input, return inspection, tax audits, etc. The Indian government recently announced the use of artificial intelligence and machine learning in the tax assessment system in order to handle the evolving tax landscape in conjunction with the use of analytics. In the field of taxes, artificial intelligence, or AI, is a relatively recent development.

Cloud based adaptive learning system: virtual reality and augmented reality assisted educational pedagogy development on clinical simulation

An adaptive learning system provides support for student’s academic progress by varying learning routes and pedagogical contents to satisfy various students’ unique academic needs. The primary goal of this research work is to enhance and expand occupational efficiency through the use of technological pedagogical content knowledge (TPCK) frameworks in nursing education. The authors developed an adaptive federated cloud computing learning system in order to better prepare students for the demands of real-world professional practice. The article examined the use of virtual reality(VR) and augmented (AR) technologies in nursing education and developed an instrument that skillfully combines knowledge from the reputable literature on clinical competencies with the peculiarities and ingenuousness particular to virtual simulations. Designated for the remote sharing and utilization of combined educational resources, cloud computing is a distributed information communication technology (ICT) infrastructure built on the Internet of Things (IoT) framework. To increase the occupational efficiency among the nurses and midwives, an educational simulation applied in a way that gamifies the curriculum component for interactive educational pedagogy will be necessary. As a completely integrated part of the curriculum, simulation has proven to be beneficial for nursing students at all levels of instruction. Nursing educators have a plethora of options at their disposal to introduce simulation-based learning approaches into their curricula in the modern era. A three-dimensional (3D) interactive environment that provides users with a sense of spatial presence is created through computer technology, which is an immersive digital ecosystem of VR and AR utilized to improve teaching and learning in nursing education. In this study, the authors offered a cost- effective clinical simulation laboratory for clinical students, nurses, midwives, and practicing healthcare professionals in a manner that ensures constant learning and occupational efficiency by adopting the TPCK model in its central discussion and implementation. The TPCK model has demonstrated how to recognize the boundaries between technological components and pedagogical structures as well as how they are connected when creating facts in nursing education.

‘We wouldn’t have missed it for the world’: hosting a polycentric sporting mega event in pandemic times

ABSTRACT This paper examines the polycentric hosting of a Sporting Mega Event (SME) in pandemic times. Semi-structured interviews were conducted with 13 stakeholders in senior management positions who were involved in the planning, organisation, and delivery of the UEFA EURO 2020 football tournament in a sample of host cities. Three themes were developed that describe the varied perspectives of UEFA and host city representatives on how they responded to the challenge of hosting a SME during a pandemic. The first theme ‘Reorienting pre-pandemic plans’ presents an alternative model of tournament planning as a system of spontaneous order (Polanyi [1953] 1998), involving a large number of host cities mutually adjusting to COVID-19 policies and guidance. The second theme ‘Dialogue and managing conflict’ demonstrates how the usual overarching system of rules proved difficult for UEFA to standardise. The third theme ‘Putting COVID-19 policies into practice (or not)’ revealed that pandemic rules were not seen as useful to some fans and stadium staff, making their enforcement more difficult to implement. It remains to be seen whether the polycentric hosting of EURO 2020 will have lasting implications on UEFA’s governance over SMEs.

IGA Approximations of Elastic Interfaces and their Defects in an Elastic Medium with Couple Stress

AbstractThe objective of this work is to develop and implement a computational algorithm for calculating stress and couple-stress fields induced by bulk and interfacial line defects such as dislocations and generalized disclinations within phase/grain boundaries. The thermodynamic driving forces on line and planar defects, responsible for coupled plasticity and interface motion, fully coupled to stress, couple-stress and applied boundary conditions are also computed. A continuum approach for small deformations is considered following the formulation outlined in Acharya and Fressengeas (Continuum mechanics of the interaction of phase boundaries and dislocations in solids. In: Differential Geometry and Continuum Mechanics, pages 123–165, 2015), extended herein in the thermodynamics to accommodate physically necessary ingredients that arose in the modeling in Zhang and Acharya (J Mech Phys Solids 119:188–223, 2018), Zhang et al. (J Mech Phys Solids 114:258–302, 2018). Constitutive relations are derived from kinematics, balance laws and from the use of the second law of thermodynamics in global form. One of the challenges presented by this approach is the inclusion of couple stresses, Toupin (Arch Rational Mech Anal 17(2):85–112, 1964), and the consequent treatment of 4th order systems arising from the equations of balances of linear and angular momentum. In order to deal with these equations, the classical FEM approach is replaced by iso-geometric analysis (IGA), as proposed by Hughes et al. (Comput Methods Appl Mech Eng 194(39):4135–4195, 2005). Results on stress and couple stress fields of the various defects involved are computed. Further, the coupling of the dislocation density with the eigenwall allows for the capturing of the shear parallel to the grain boundary, which has been observed experimentally and through molecular dynamics.

Dilatonic dynamics of baryonic crystals, branes, and spheres

We systematically analyze the impact of dilatonic dynamics on Skyrme spheres, crystals, and branes. The effects of the dilatonic model parameters, encompassing different underlying near-conformal dynamics, on the macroscopic properties of skyrmions such as their mass and radius are discussed. For spheres and crystals we identify special values of the ratio of the decay constants for which the second order differential equations reduce to a solvable first order system. Additionally, in the case of the crystals, the dilaton presence spatially separates the baryon and isospin charge distributions. For branes, we show how the dilaton smooths out their configurations. Our results are expected to have wide implications from the study of near-conformal dynamics stemming from QCD-like theories to phenomenological investigations of nuclear matter in extreme regimes. Published by the American Physical Society 2024

Stress and Pregnancy Outcomes: A Review of the Literature.

The human body has the ability to adapt to changing circumstances, and mobilizes various biological systems in order to do so. When exposed to stressful conditions, the endocrine, nervous, and immune systems come together to aid in maintaining homeostasis; however, during periods of chronic stress, these systems can become maladaptive and lead to long-term detrimental health outcomes. Amongst the lingering effects associated with chronic stress exposure, increasingly, studies are identifying a link to adverse pregnancy and neonatal outcomes. This review explores what has been uncovered in the field to date, and examines the effects of stress on fertility and gestation. Establishing additional factors which put women at risk for adverse pregnancy outcomes can aid in identifying a vulnerable population who could benefit from early stress-reducing interventions.

Evidence of conformational changes and self-aggregation of 1,2-Bis(4-pyridyl)ethylene in solutions with ethanol

In this work, we report on a concentration and temperature dependent study of the 1,2-Bis(4-pyridyl)ethylene (BPE) – ethanol solutions by means of ultrasonic relaxation spectroscopy. The results revealed two distinct relaxation processes that follow Debye-type frequency dependence. Despite the presence of both processes in the full concentration range studied, the low-frequency relaxation process, related to conformational change between the trans- and gauche-BPE conformers, dominates the acoustic spectra in the low-concentration range, while diminishes at higher concentrations with a parallel enhancement of the high-frequency relaxation process, which is attributed to the self-association of BPE molecules. Quantum mechanical calculations were performed to investigate the energetics of the trans- and gauche-conformers. The trans-species was found more thermodynamically stable than the gauche-conformer. By applying the Synchronous Transit-Guided Quasi-Newton (STQN) methodology, we confirmed the presence of a single transition structure. From the temperature dependence of the acoustic properties, we estimated the activation enthalpy and the enthalpy difference between the two conformers. Density Functional Theory (DFT) calculations have been applied to attain the corresponding enthalpies that were found close to the experimental values. Molecular docking calculations established the self-aggregation mechanism between BPE monomers forming three types of dimeric units, namely the trans-trans, the gauche-gauche and the trans-gauche dimer species with the latter found to be the most thermodynamically favorable. The concentration dependence of the sound velocity, mass density and shear viscosity evidenced the formation of BPE aggregates. From the temperature dependence of the acoustic spectra, the thermodynamic properties of the self-aggregation mechanism of BPE were also determined. Based on the vibrational spectroscopic data, the population of the gauche conformers was found to increase with concentration at the expense of the population of the trans conformers. From the study of the vibrational properties of the system in the short-rage order, we cannot exclude the presence of a specific dimer type in the overall structure. Nevertheless, regarding to the binding score of the trans-gauche dimer (-1.25 kcal/mol), this species is the most thermodynamically stable and most likely its population is higher in dense solutions relative to the other two dimer species.

Fractional-Order Mathematical Modeling and Stability Analysis of Tumor-Immune System Relation Including Chemotherapy Drug Effect

Cancer diseases rank second in global mortality rates. Among the prevalent approaches for treating tumors, chemotherapy stands out as a prominent method capable of reducing tumor size and managing the advancement of cancer ailments. To gain deeper insights into the intricacies of chemotherapy mechanisms, we devised a Fractional-order mathematical model, depicting tumor growth in the presence of chemotherapy. This comprehensive model encompasses both the immune system's response and the effects of drug therapy. To demonstrate that the system is biologically meaningful, we examined the existence and uniqueness of solutions and proved the positivity and boundedness of solutions. We characterize the dynamics properties of this differential equation model by finding the equilibrium points and exploring the stability conditions in a range of model parameters. In addition, we have performed numerical simulations considering different parameter values. Furthermore, to demonstrate the memory effect of the fractional derivative, we have simulated the dynamic behavior of the system for different orders of fractional derivatives. So, we have concluded that the memory effect occurs as the α decreases from 1 and the chemotherapy drug is quite effective on the populations. We hope that this work will contribute to helping medical scientists take the necessary measures during the screening process and treatment.

Hopf bifurcation control of memristor-based fractional delayed tri-diagonal bidirectional associative memory neural networks under various controllers

In this paper, authors present a memristor-based fractional order system of tri-diagonal bidirectional associative memory neural networks (TdBAMNNs) incorporating leakage and communication delays. The existence and uniqueness theorem is established for the memristor-based fractional-order TdBAMNNs system. Analysis of Hopf bifurcation anti-control is conducted using various feedback controllers by exploring single-parameter and double-parameter approaches. A study of the stability switching curves is undertaken to determine the direction of stability transitions in the system. The theoretical results and graphical illustrations are validated through numerical simulations to exhibit their feasibility. Comparative analysis of the system’s dynamical behavior under different controllers is performed. This paper comprehensively explores the proposed memristor-based system, proving its theoretical underpinnings, and analyzing stability through bifurcation control strategies and comparative assessments under different control scenarios.

Numerical Modeling of Two-Phase Fluid Filtration for Carbonate Reservoir in Two-Dimensional Formulation

This work considers the isothermal process of incompressible viscous fluid filtration in an oil-saturated, fractured-porous reservoir. A study of the pressure and water saturation distribution process is carried out for a case in which a production well is put into operation. For this problem, i.e., a mathematical model in a two-dimensional formulation, a numerical method and a parallel algorithm are proposed. The mathematical model of two-phase filtration is written in accordance with the classical laws of continuum mechanics and Darcy’s law and also includes a function of fluid exchange between low-permeability pores and high-permeability natural fractures within the framework of the Warren–Root model. The numerical solution is based on the finite-difference method and a splitting scheme of physical processes and spatial coordinates. For a split system with respect to piezoconductivity, an implicit finite-difference scheme with fixed saturations is constructed, and with respect to saturation transfer, explicit and implicit difference schemes are constructed. For parallel implementation of the developed numerical approach, a method based on geometric parallelism is selected. Testing of the developed method is performed using the example of calculating liquid mass transfer for a wide range of parameters. To verify the model, the obtained calculated pressure curves are compared with field data recorded by a deep-well measuring device. The results allow for estimation of the distribution of reservoir pressure and water saturation depending on the permeability of the fracture set and the pore part. The obtained results allow for monitoring of well operations, reducing unexpected accident risks and optimizing the development system in order to increase oil production in fractured-porous reservoirs. Computational experiments confirm the efficiency of the developed numerical algorithm and its parallel implementation.

Optimal Configuration of Electricity-Heat Integrated Energy Storage Supplier and Multi-Microgrid System Scheduling Strategy Considering Demand Response

Shared energy storage system provides an attractive solution to the high configuration cost and low utilization rate of multi-microgrid energy storage system. In this paper, an electricity-heat integrated energy storage supplier (EHIESS) containing electricity and heat storage devices is proposed to provide shared energy storage services for multi-microgrid system in order to realize mutual profits for different subjects. To this end, electric boiler (EB) is introduced into EHIESS to realize the electricity-heat coupling of EHIESS and improve the energy utilization rate of electricity and heat storage equipment. Secondly, due to the problem of the uncertainty in user-side operation of multi-microgrid system, a price-based demand response (DR) mechanism is proposed to further optimize the resource allocation of shared electricity and heat energy storage devices. On this basis, a bi-level optimization model considering the capacity configuration of EHIESS and the optimal scheduling of multi-microgrid system is proposed, with the objectives of maximizing the profits of energy storage suppliers in upper-level and minimizing the operation costs of the multi-microgrid system in lower-level, and solved based on the Karush-Kuhn-Tucker (KKT) condition and Big-M method. The simulation results show that in case of demand response, the total operation cost of multi-microgrid system and the total operation profit of EHIESS are 51,687.73 and 11,983.88 CNY, respectively; and the corresponding electricity storage unit capacity is 9730.80 kWh. The proposed model realizes the mutual profits of EHIESS and multi-microgrid system.

The Impact of White Noise on Chaotic Behavior in a Financial Fractional System with Constant and VariableOrder: A Comparative Study

In this study, we investigated the impact of white noise on the chaotic dynamics of a financial system with Caputo fractional derivatives of constant- and variable-order. We solve thesefractional financial systems numerically. We analyze the chaotic behavior of these fractional-order hyperchaotic systems through simulations, study the effects of white noise on chaotic dynamics, and provide a comparison between fractional hyperchaotic systems of constant and variable orders. The study reveals that white noise can either amplify or suppress chaos, with significant differences observed between the constant- and variable-order cases. We obtained numerous intriguing graphical findings for the model by evaluating various scenarios. The findings provide useful information for better understanding financial market dynamics in the presence of noise.

Multi-step Residual Power Series Method for Solving Stiff Systems

In this paper, an efficient algorithm based on the residual power series method (RPSM) is presented to solve stiff systems of Caputo fractional order. We apply the RPSM on subintervals to get approximate solutions of these types of systems. The RPSM has advantages that it is suitable to solve linear and nonlinear systems and it gives high accurate results. Modifying this technique to multi-step RPSM considerably reduces the number of arithmetic operations and so reduces the time, especially when dealing with Stiff systems. Several numerical examples are given to show the efficiency, simplicity and the accuracy of the proposed method. Comparing classical RPSM with the new multi-step scheme shows that multi-step RPSM controls the convergence behaviour of the stiff systems. That is, the comparison reveals that MS-FRPSM reduces both absolute and residual errors. More iterations and a smaller step size lead to higher accuracy. Moreover, in MS-FRPSM, the intervals of convergence for the series solution will increase.

Saving energy resources during operation of rolling stock of underground electrified transport

Purpose. To analyze the energy saving reserves under the conditions of implementation and integration of the system in order to find rational driving modes in the general system of managing underground electrified transport. Methodology. The work presents the method for processing data arrays obtained experimentally with the help of a measuring system and theoretically with the use of the “Rational Trajectory” software. Findings. Experimental studies were carried out using a testing system created on the basis of a refurbished train with energy recovery system. Theoretical studies were carried out using the “Rational Trajectory” software, which is based on the principle of solving a multi-criteria problem by the method of the main criterion. The minimum amount of electricity consumption from the overhead contact line was chosen as the main criterion. The software was developed in the LabVIEW graphical programming environment in order to determine the rational modes of driving rolling stock and energy indicators in a given area of its operation. The amount of electricity consumed for traction and the amount of electricity generated by the train during regenerative braking were determined based on the results of experimental and theoretical studies, respectively, under typical and rational modes of driving the train for given identical operating conditions. Originality. Further research on the analysis of energy saving reserves on the rolling stock of underground electrified transport was achieved due to the introduction of a system for finding a rational driving mode. Practical value. It has been established that the implementation and incorporation of the “Rational Trajectory” software into the train control system will save up to 14.7 % of the amount of electricity consumed for traction, compared to typical modes operation on a given track section.