Dynamics Of Different Types Research Articles

Kalman filter applied to Thevenin’s modeling of a lead-acid battery

<span>This article determines the internal parameters of a battery analyzed from its circuit equivalent, reviewing important information that can help to identify the battery’s state of charge (SOC) and its state of health (SOH). Although models that allow the dynamics of different types of batteries to be identified have been developed, few have defined the lead-acid battery model from the analysis of a filtered signal by applying a Kalman filter, particularly taking into account the measurement of noise not just at signal output but also at its input (this is a novelty raised from the experimental). This study proposes a model for lead-acid batteries using tools such as MATLAB<sup>®</sup> and Simulink<sup>®</sup>. First, a method of filtering the input and output signal is presented, and then a method for identifying parameters from 29 charge states is used for a lead-acid battery. Different SOCs are related to different values of open circuit voltage (OCV). Ultimately, improvements in model estimation are shown using a filter that considers system and sensor noise since the modeled and filtered signal is closer to the original signal than the unfiltered modeled signal.</span>

11-year dynamics of coronal hole and sunspot areas

Abstract The paper presents study the 11-year dynamics of solar activity on the basis of new observational material on coronal holes (CHs) and sunspots in the period from May 13, 2010 to May 13, 2021. We used the Heliophysics Event Knowledgebase (HEK) to obtain information on CHs areas. For 11 years of observations, we processed about 18000 CHs. Slightly more than 8000 are polar, the rest are nonpolar CHs. The statistical volume of the presented material is quite extensive and gives grounds for the study of the dynamics of different types of CHs during the cycle. Our research has shown: in the 24th solar activity cycle, the South led for polar CHs and the North led for nonpolar ones. We established a relationship between the number and area of CHs and the phase of the solar cycle. The number and daily total area of polar CHs increases at the minima of solar activity and decreases at the maximum of the cycle. This is consistent with the general concept of polar CHs as the main source of the solar dipole magnetic field. An asymmetry in both the number and areas of polar coronal holes in the northern and southern hemispheres is observed. It is shown that the areas of nonpolar CHs change quasi-synchronously with sunspot activity, which suggests a physical connection between these two phenomena.

The co-circulating transmission dynamics of SARS-CoV-2 Alpha and Eta variants in Nigeria: A retrospective modeling study of COVID-19.

BackgroundThe COVID-19 pandemic poses serious threats to public health globally, and the emerging mutations in SARS-CoV-2 genomes has become one of the major challenges of disease control. In the second epidemic wave in Nigeria, the roles of co-circulating SARS-CoV-2 Alpha (ie, B.1.1.7) and Eta (ie, B.1.525) variants in contributing to the epidemiological outcomes were of public health concerns for investigation.MethodsWe developed a mathematical model to capture the transmission dynamics of different types of strains in Nigeria. By fitting to the national-wide COVID-19 surveillance data, the transmission advantages of SARS-CoV-2 variants were estimated by likelihood-based inference framework.ResultsThe reproduction numbers were estimated to decrease steadily from 1.5 to 0.8 in the second epidemic wave. In December 2020, when both Alpha and Eta variants were at low prevalent levels, their transmission advantages (against the wild type) were estimated at 1.51 (95% credible intervals (CrI) = 1.48, 1.54), and 1.56 (95% CrI = 1.54, 1.59), respectively. In January 2021, when the original variants almost vanished, we estimated a weak but significant transmission advantage of Eta against Alpha variants with 1.14 (95% CrI = 1.11, 1.16).ConclusionsOur findings suggested evidence of the transmission advantages for both Alpha and Eta variants, of which Eta appeared slightly more infectious than Alpha. We highlighted the critical importance of COVID-19 control measures in mitigating the outbreak size and relaxing the burdens to health care systems in Nigeria.

Weather‐driven demography and population dynamics of an endemic perennial plant during a 34‐year period

Abstract Increased anthropogenic influence on the environment has accentuated the need to assess how climate and other environmental factors drive vital rates and population dynamics of different types of organisms. However, to allow distinction between the effects of multiple correlated variables, and to capture the effects of rare and extreme climatic conditions, studies extending over decades are often necessary. In this study, we used an individual‐based dataset collected in three populations of Pulsatilla vulgaris subsp. gotlandica during 34 years, to explore the effects of variation in precipitation and temperature on vital rates and population dynamics. Most of the observed conspicuous variation in flowering among years was associated with differences in precipitation and temperature in the previous summer and autumn with a higher incidence of flowering following summers with high precipitation and low temperatures. In contrast, climatic variables had no significant effects on individual growth or survival. Although the weather‐driven variation in flowering had only moderate absolute effects on the population growth rate, simulated persistent changes in average precipitation and temperature resulted in considerable reductions in population sizes compared with current conditions. Analyses carried out with subsets of data consisting of 5 and 10 years yielded results that strongly deviated from those based on the full dataset. Synthesis. The results of this study illustrate the importance of long‐term demographic monitoring to identify key climatic variables affecting vital rates and driving population dynamics in long‐lived organisms.

Power dynamics in organisations and the role of information systems

Power dynamics in organisations and the role of information systems

Random walks on weighted networks: a survey of local and non-local dynamics

AbstractIn this article, we present a survey of different types of random walk models with local and non-local transitions on undirected weighted networks. We present a general approach by defining the dynamics as a discrete-time Markovian process with transition probabilities expressed in terms of a symmetric matrix of weights. In the first part, we describe the matrices of weights that define local random walk dynamics like the normal random walk, biased random walks and preferential navigation, random walks in the context of digital image processing and maximum entropy random walks. In addition, we explore non-local random walks, like Lévy flights on networks, fractional transport through the new formalism of fractional graph Laplacians, and applications in the context of human mobility. Explicit relations for the stationary probability distribution, the mean first passage time and global times to characterize random walks are obtained in terms of the elements of the matrix of weights and its respective eigenvalues and eigenvectors. Finally, we apply the results to the analysis of particular local and non-local random walk dynamics, and we discuss their capacity to explore several types of networks. Our results allow us to study and compare the global dynamics of different types of random walk models.

A Structural Equation Modelling Evaluation of Antecedents and Interconnections of Call Centre Agents’ Intention to Quit

Call centers play a significant role in the operational dynamics of different types of businesses. This is especially the case because a call center agent’s demeanor can impair or engender customer satisfaction, which has ramifications for business patronage. Unfortunately, the pressures associated with the role of the call center agent have made staff attrition a norm in the industry. While this does not augur well for the call center or the organizations that they serve, the role of possible antecedents in the equation of staff attrition in South African call centers remains largely unexplored. Using a structural equation modeling approach, this study examined the interconnections between customer orientation, knowledge management, job satisfaction, and employees’ intention to quit. Additionally, the mediating influence of job satisfaction on the association between customer orientation and knowledge management of the intention to quit is examined. This study found significant relationships between knowledge management, customer orientation, and job satisfaction and the dependent variable (intention to quit). In addition, this study establishes that the extent to which job satisfaction may mediate the influence on the intention to quit hinges on the organizational element considered. Two factors limit the extent to which the findings from this study can be generalized. First, this study focused on the call center setting in South Africa. Second, convenience sampling was used in this study. This study points to critical operational practices that call center managers can embrace toward enhancing job satisfaction and reducing intention to quit propensity. Using structural equation analysis, we contend that call centers in the South African setting would effectively address staff attrition if appropriate organizational practices are endorsed toward ensuring employee job satisfaction.

Long-Term Dynamics of Different Surface Water Body Types and Their Possible Driving Factors in China

Various surface water bodies, such as rivers, lakes and reservoirs, provide water and essential services to human society. However, the long-term spatiotemporal dynamics of different types of surface water bodies and their possible driving factors over large areas remain very limited. Here, we used unprecedented surface water data layers derived from all available Landsat images and further developed two databases on China’s lakes and reservoirs larger than 1 km2 to document and understand the characteristics of changes in different water body types during 2000 to 2019 in China. Our results show that China is dominated by permanent water bodies. The areas of permanent and seasonal water bodies in China increased by 16,631.02 km2 (16.72%) and 16,994.95 km2 (25.14%), respectively, between 2000 and 2019, with permanent and seasonal water bodies exhibiting divergent spatial variations. Lakes and artificial reservoirs larger than 1 km2, which collectively represent a significant proportion of the permanent water bodies in China, displayed net increases of 6884.52 km2 (10.71%) and 4075.13 km2 (36.10%), respectively, from 2000 to 2019; these increases accounted for 41.40% and 24.50%, respectively, of the total permanent water body increment. The expanding lakes were mainly distributed on the Tibetan Plateau, whereas the rapidly growing reservoirs were mainly located on the Northeast Plain and Eastern Plain. Statistical analyses indicated that artificial reservoirs were an important factor controlling both permanent and seasonal water body changes in most of provinces. Climate factors, such as precipitation and temperature, were the main influencing factors affecting the changes in different water bodies in the sparsely populated Tibetan Plateau.

Numerical scheme for the far-out-of-equilibrium time-dependent Boltzmann collision operator: 1D second-degree momentum discretisation and adaptive time stepping

Study of far-from-equilibrium thermalisation dynamics in quantum materials, including the dynamics of different types of quasiparticles, is becoming increasingly crucial. However, the inherent complexity of either the full quantum mechanical treatment or the solution of the scattering integral in the Boltzmann approach, has significantly limited the progress in this domain. In our previous work we had developed a solver to calculate the scattering integral in the Boltzmann equation. The solver is free of any approximation (no linearisation of the scattering operator, no close-to-equilibrium approximation, full non-analytic dispersions, full account of Pauli factors, and no limit to low order scattering) [1]. Here we extend it to achieve a higher order momentum space convergence by extending to second degree basis functions. We further use an adaptive time stepper, achieving a significant improvement in the numerical performance. Moreover we show adaptive time stepping can prevent intrinsic instabilities in the time propagation of the Boltzmann scattering operator. This work makes the numerical time propagation of the full Boltzmann scattering operator efficient, stable and minimally reliant on human supervision.

Dielectric and electro-mechanic nonlinearities in perovskite oxide ferroelectrics, relaxors, and relaxor ferroelectrics

The polarization and strain response of ferroelectric materials at electric fields below the macroscopic coercive field is of paramount importance for the operation of many electronic devices. The response of real ferroelectric and related materials is, in general, complex and difficult to interpret. The reason for this is that many processes in a ferroelectric material contribute to its properties, often concurrently. Examples include the motion of ferroelectric and ferroelastic domains, the presence of domains within domains, the dynamics of different types of polar nano-entities, the interaction of polar nano-entities (e.g., polar nanoregions in relaxors) with the strain and polarization within domains, motion of defects, and rearrangement of defect clusters and their interaction with polarization and strain. One signature of these processes is nonlinearity of the strain and polarization. Most ferroelectrics exhibit nonlinear response at all practical field levels, meaning that the apparent material coefficients depend on the amplitude of the driving excitation. In this paper, we show that an investigation of nonlinear behavior is a sensitive way to study various mechanisms operating in dielectric and piezoelectric materials. We review the basic formalism of the nonlinear description of polarization and strain, give a physical interpretation of different terms, and illustrate this approach on numerous examples of relaxors, relaxor ferroelectrics, hard and soft ferroelectrics, and morphotropic phase boundary compositions. An experimental approach based on a lock-in technique that is well suited for such studies is also discussed.

The effect of morphology and particle-wall interaction on colloidal near-wall dynamics.

We investigated the near-wall Brownian dynamics of different types of colloidal particles with a typical size in the 100 nm range using evanescent wave dynamic light scattering (EWDLS). In detail we studied dilute suspensions of silica spheres and shells with a smooth surface and silica particles with controlled surface roughness. While the near wall dynamics of the particle with a smooth surface differ only slightly from the theoretical prediction for hard sphere colloids, the rough particles diffuse significantly slower. We analysed the experimental data by comparison with model calculations and suggest that the deviating dynamics of the rough particles are not due to increased hydrodynamic interaction with the wall. Rather, the particle roughness significantly changes their DLVO interaction with the wall, which in turn affects their diffusion.

Ретроспективный анализ деятельности морских торговых портов в годы первых пятилеток и их роль в индустриализации экономики СССР (1928–1940 гг.)

The article highlights the general regularities of the economic development of commercial sea ports in the USSR and defines their role in industrialization of the country. For the first time there has been carried out a comparative analysis of sea port cargo turnover dynamics in relation to the ports of Great Britain, Germany, Italy, the Netherlands, the USA and France. The rates of port cargo turnover growth are investigated in comparison with the rates of industrial production growth, the volume of railway and inland water transport. The changes in the main cargo flows connected to the industrialization of the economy in all sea basins of the USSR have been studied. The dynamics of different types of cargo transshipment has been investigated. There has been stated the increasing rate of coastal cargo transshipment against the significant decrease in the export-import cargo transshipment due to the policy of self-reliance. The structure of foreign commercial cargos has been studied, a significant excess of exports over imports has been revealed. It has been found that the high growth rates of cargo turnover in the Soviet ports were due to the increase in the volume of oil cargo transshipment in the ports of the Caspian Sea. There have been calculated the average age and deadweight of Soviet ships in 1939, compared to the similar average international parameters and figures of the previous years. It was determined how the port's technical characteristics and lack of funding influenced these parameters. Investments to the seaports were hundreds of times less than investments to heavy industry and railway transport, and dozens of times less in inland waterways, since the seaports were not the priority objects in the program of economic industrialization. As a result, plans were not fulfilled, ships were idling in the ports, and labor productivity was low. It has been inferred that the activity of seaports during the first five-year plans was not profitable. There have been studied the specific features of the state system of seaports management during the first five-year plans.

Agent-based modeling of supply disruptions in the global rare earths market

Several independent assessments have identified rare earth elements (REEs) as critical materials, notably neodymium (Nd), praseodymium (Pr), and dysprosium (Dy) used in permanent magnets. Factors affecting their criticality include expected growth in demand arising from their unique performance-enhancing properties in consumer, energy, and military applications and the supply risk associated with China's dominance in their production. We demonstrate the use of Argonne's Global Critical Materials (GCMat) agent-based model to explore the possible consequences to REE market dynamics of different types of regional supply disruptions including a temporary loss of production, shutdown of capacity, and diversion of supply. Results suggest that supply disruptions may foster earlier and more REE mine starts outside of China, although some of these mines may not be able to sustain operations post disruption. Further, price and associated market responses such as production, capacity, and demand tended to extend beyond the disruption period. Such market impacts in the magnet supply chain could affect the costs and availability of a number of emerging clean energy technology applications such as electric vehicles and wind turbines. In the future, GCMat could be used to evaluate the effectiveness of mitigation strategies — including recycling, conservation, product substitution, and diversification of supplies — on reducing the severity of disruptions in REE markets.

Soil carbon dynamics in different types of subtropical forests as determined by density fractionation and stable isotope analysis

Quantifying carbon (C) dynamics with forest land-use change is essential for predicting C sequestration and stabilization. Here, we combined density fractionation and stable isotope analysis to examine soil C dynamics after primary native broadleaf forests (BF) were converted to secondary forests (SF) and plantation forests (PF). The results showed that soil C stock at 0–30 cm depth decreased significantly from BF (70.8 Mg ha−1) to SF (60 Mg ha−1) and PF (53.9 Mg ha−1). Both soil C concentration and stock decreased, but soil δ13C of the light and heavy fractions increased, and these increases were more evident in the topsoil (0–10 cm) than in the subsoil (10–30 cm). The decrease of the heavy fraction C stocks accounted for 52.7% and 69.7% of the reduction of bulk soil C stocks with conversion of BF to SF and PF, respectively. Analysis of δ13C revealed that the input of new C into the light fraction of soil at 0–10 cm depth decreased by 13.1% with conversion of BF to SF, and by 34.0% with conversion of BF to PF. The decreases of soil C stocks in density fractions were primarily explained by soil properties (β = 0.70) but also by vegetation biomass C (β = 0.26), and were closely correlated with soil moisture content (0.69, the highest eigenvalue among soil properties) and floor litter biomass C (0.75, the highest eigenvalue among biomass C categories). Our findings help clarify the contrasting mechanisms explaining the dynamics of light and heavy fraction of soil C, and highlight the importance of both vegetation and soil in controlling changes in soil C dynamics in response to forest conversion. Accordingly, we recommend that management policies and actions should maximize biomass C inputs of degraded forests and minimize C losses. It follows that the preservation of primary forests might increase ecosystem C sequestration and thereby mitigate climate change.

Analysis of Hybrid Vector Beams Generated with a Detuned Q-Plate

We use a tunable commercial liquid-crystal device tuned to a quarter-wave retardance to study the generation and dynamics of different types of hybrid vector beams. The standard situation where the q-plate is illuminated by a Gaussian beam is compared with other cases where the input beam is a vortex or a pure vector beam. As a result, standard hybrid vector beams but also petal-like hybrid vector beams are generated. These beams are analyzed in the near field and compared with the far field distribution, where their hybrid nature is observed as a transformation of the intensity and polarization patterns. Analytical calculations and numerical results confirm the experiments. We include an approach that provides an intuitive physical explanation of the polarization patterns in terms of mode superpositions and their transformation upon propagation based on their different Gouy phase. The tunable q-plate device presents worthy advantages, since it allows a compact and efficient generation of pure and hybrid vector beams to study these effects.

Transient absorption spectroscopy as a promising optical tool for the quality evaluation of graphene layers deposited by microwave plasma

The qualified analysis of structure, morphology and defects in graphene is crucial for graphene layers evaluation and development of various electro-optical applications. In this work, we present the detailed analysis of properties of planar graphene and vertical graphene nanosheets (VGNs) prepared by means of microwave plasma enhanced chemical vapour deposition method (PECVD), employing common analysis methods (scanning electron microscopy, atomic force microscopy, X-ray photoelectron spectroscopy, and Raman scattering spectroscopy), as well as ultrafast transient absorption spectroscopy (TAS) technique with different excitation wavelengths (at 350, 400 and 700 nm) to analyze excited state relaxation dynamics in different types of graphene. By measuring relaxation duration (or hot electrons cooling dynamics that originates from electron-phonon interactions, leading to phonon-phonon interactions) we showed that TAS provides with the information about phonons and defects in graphene. The complex analysis of graphene layers, in parallel to the TAS measurements, demonstrates that TAS analysis of the excited state dynamics in graphene might lead to the creation of effective methodology of control of quality of graphene in terms of effective defect analysis.

Real-time intraoperative dynamics of white cataract-intraoperative optical coherence tomography-guided classification and management.

To evaluate morphological characteristics and intraoperative dynamics of different types of white cataract using intraoperative optical coherence tomography (iOCT). Dr. Rajendra Prasad Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi, India. Prospective interventional study. Fifty eyes with white cataract undergoing phacoemulsification were evaluated. The primary outcome measure was the classification of white cataract based on morphology and intraoperative dynamics on iOCT. The secondary outcome measure was rhexis-related complications. Four types of white cataract were identified based on iOCT-type I (9 eyes), type II (3 eyes), type III (24 eyes), and type IV (14 eyes). Type I had regularly arranged lamellar cortical fibers, type II had continuous hyperreflective bands of cortical fibers with intralenticular clefts, type III had intralenticular clefts combined with areas of homogenous ground-glass appearance, and type IV had homogenous ground-glass appearance of the anterior lens cortex. Capsulorhexis in type I cataract was uneventful. In type II cataract, cortical bulge was observed in the anterior chamber on creating the initial nick, indicating raised intralenticular pressure (ILP) with an imminent risk of rhexis extension. A bimanual irrigation/aspiration was performed until lowering of ILP was observed on iOCT. In types III and IV, fluid release was observed on initiation of rhexis leading to partial (type III) or complete (type IV) lowering of ILP, with a mild-moderate risk of capsulorhexis extension. A continuous curvilinear capsulorhexis was achieved in all cases, with no case of posterior capsular tear or vitreous loss. Intraoperative OCT helped elucidate intraoperative dynamics of the spectrum of white cataracts and facilitates completion of capsulorhexis.

Joint Bottom-Up Method for Hierarchical Time-Series: Application to Australian Tourism

Many applications involve a hierarchy of time-series, where values at the bottom level aggregate to values at higher levels. Forecasts of such hierarchical data need to be accurate, probabilistic, and coherent in the sense of respecting hierarchical aggregation. While recent developments have explicitly modeled every time-series in the hierarchy, we show, under general conditions, that hierarchical data can be modeled jointly by considering only its bottom-level series and their contemporaneous covariance. Inspired by this result, we devise a Bayesian method that models bottom-level series jointly, takes into account their contemporaneous covariance, and performs automatic selection of lag terms, both within and across series. The model copes with high-dimensional data, and outputs both point and probabilistic forecasts. Additionally, it returns posterior distributions of all parameters, which can be used for inference. As a case study, we apply our method to make recommendations on planning and promotion of domestic tourism in Australia. Our model reveals the hidden spatio-temporal dynamics of different types of domestic tourism in Australia, and allows us to explore how promotional investments could be localized to develop tourism in accordance with the declared desiderata of the Australian government.

Quantum signatures of transitions from stable fixed points to limit cycles in optomechanical systems

Optomechanical systems, due to its inherent nonlinear optomechanical coupling, owns rich nonlinear dynamics of different types of motion. The interesting question is that whether there exist some common quantum features to infer the nonlinear dynamical transitions from one type to another. In this paper, we have studied the quantum signatures of transitions from stable fixed points to limit cycles in an optomechanical phonon laser system. Our calculations show that the entanglement of stable fixed points in the long run does not change with time, however, it will oscillate periodically with time at the mechanical vibration frequency for the limit cycles. Most strikingly, the entanglement quite close to the boundary line keeps as a constant, and it is very robust to the thermal phonon noise, as strong indications of this particular classical transitions.

CONTEXTUAL FACTORS OF METAPHORICAL FRAMING IN ECONOMIC DISCOURSE

This study takes an integrated discourse-cognitive approach to the analysis of contextual factors that motivate conceptual evolution of metaphorical frames in economic discourse. In contrast to looking at conceptual metaphor models in isolation or out of context, doing metaphor research from the perspective of contextual factors gives insight into the motivation of metaphor choice and origins of conceptual evolution as well as facilitates understanding and interpretation of metaphorical meaning construction. The evolutionary aspects of metaphorical frames in extra linguistic context of economic discourse have not been thoroughly covered in Russian research literature. This paper attempts to identify some contextual effects on metaphorical framing in economic discourse and analyze some examples evidencing the importance of discourse-cognitive approach for metaphorical frames evolution research. The theoretical framework of this study is formed by the groundbreaking theories of conceptual metaphor, metaphorical framing, conceptual evolution and abundant research examining metaphor dynamics in different types of discourse. The empirical data gleaned and analyzed in this paper indicate the dynamic variation of metaphorical frames motivated by the social context of economic discourse production.