Theoretical Means Research Articles

Further study on Hopf bifurcation and hybrid control strategy in BAM neural networks concerning time delay

<abstract><p>Delayed dynamical system plays a vital role in describing the dynamical phenomenon of neural networks. In this article, we proposed a class of new BAM neural networks involving time delay. The traits of solution and bifurcation behavior of the established BAM neural networks involving time delay were probed into. First, the existence and uniqueness is discussed using a fixed point theorem. Second, the boundedness of solution of the formulated BAM neural networks involving time delay was analyzed by applying an appropriate function and inequality techniques. Third, the stability peculiarity and bifurcation behavior of the addressed delayed BAM neural networks were investigated. Fourth, Hopf bifurcation control theme of the formulated delayed BAM neural networks was explored by virtue of a hybrid controller. By adjusting the parameters of the controller, we could control the stability domain and Hopf bifurcation onset, which was in favor of balancing the states of different neurons in engineering. To verify the correctness of gained major outcomes, computer simulations were performed. The acquired outcomes of this article were new and own enormous theoretical meaning in designing and dominating neural networks.</p></abstract>

Analisis Faktor Konfirmatori untuk Mengidentifikasi Peubah Indikator Utama dalam Pengukuran Peubah Laten

Research on attitudes, preferences and behavior are research that involves latent variables. Latent variables are measured by observing some indicator variables. Indicator variables that measure a latent variable are selected based on the researcher's perspective, however, it is necessary to consider the previous of related research. Indicator variables need to have theoretical meaning, be valid and reliable in measuring latent variables. Confirmatory factor analysis (CFA) is a statistical method that can be used to determine the validity of the indicator variables. In this research, CFA is used to determine the main indicator variables that characterize the reasons for choosing a study program at a university by high school graduates (or equivalent). There are 20 indicator variables chosen to represent several latent factors such as image, job prospects, interests and campus facilities. The results indicate that the latent factors of image, job prospects, interest and facilities can be respectively represented by the majority of alumni occupying strategic positions in their careers, the easiness of alumni for getting a job, a large number of individuals in surroundings who are working as a data analysts and representative library. The findings also reveals that all the selected indicators are significant so that no indicators need to be excluded. Evaluation of the model shows that the specified model fits the analyzed data. This is indicated by the Comparative Fit Index (CFI), Root Mean Square Error of Approximation (RMSEA), and Standardized Root Mean Square Residual (SRMR) values ​​which reach good fit criteria.

Methodology of Scientific Knowledge of Educational Axiology of Europeanisation

The concrete scientific methodology of sociological research expresses the system of prevailing ruling principles of theoretical concepts, techniques, methods and means of technical regulation, which unites the complex of theoretical and methodological basis and the architecture of the outline of the sociological field of sciences and knowledge, normalized by means of regulators of the system analysis in the quality of sociological research by levels: high – fundamental and philosophical foundations of sociological knowledge; sufficient – approaches, principles, techniques, methods of general scientific interdisciplinary and fundamental knowledge; concretely determinative – set of parametric evaluation in the methods and procedures of the social and philosophical technique of theoretical and applied research. The most used philosophical methods are analysis and synthesis, induction and deduction, abstraction, generalization and specification, observation and analogy, modeling and forecasting. In the perspective of social and philosophical study, the above-mentioned methods of analysis acquire semantic application in the study of social and cultural objects of the organization in the field of education, science and innovation (namely, multidimensional analysis acquires the status of content analysis).

L’Œil du cyclone

This article probes the convergence of meteorological disaster and memory in L’Île et une nuit by Daniel Maximin and La Case du commandeur by Édouard Glissant, reading fragments of these novels through reflections lifted from spiritual autobiographies by M. Jacqui Alexander and Mimerose Beaubrun. While anglophone Black studies scholar Christina Sharpe employs weather systems and climate as figures to apprehend the pervasiveness of antiblackness in today’s world, hurricane disaster takes another form as a device used by francophone Caribbean authors to observe and disrupt the ontological negation of Black people. Tracing the multiple resonances between ‘the wake’ (Sharpe, 2016) as a prismatic theoretical tool and meanings of water, passages, and wakefulness generated by hurricanes in Glissant and Maximin, this article explores the relation between this meteorological disaster event and an expansive consciousness of the human disasters of deportation and rupture. It pays attention to homonymic language tethering the eye of the hurricane and other manifestations of suspended wind and saltwater to the ‘vision’ or modes of sensorial knowing this phenomenon confers, addressing the ways in which African diaspora authors and spiritual practitioners understand the disaster of the Middle Passage through the disaster of the hurricane as temporally amplified, immanent, and beyond human.

Affinity of Telluronium Chalcogen Bond Donors for Lewis Bases in Solution: A Critical Experimental-Theoretical Joint Study.

Telluronium salts [Ar2 MeTe]X were synthesized, and their Lewis acidic properties towards a number of Lewis bases were addressed in solution by physical and theoretical means. Structural X-ray diffraction analysis of 21 different salts revealed the electrophilicity of the Te centers in their interactions with anions. Telluroniums' propensity to form Lewis pairs was investigated with OPPh3 . Diffusion-ordered NMR spectroscopy suggested that telluroniums can bind up to three OPPh3 molecules. Isotherm titration calorimetry showed that the related heats of association in 1,2-dichloroethane depend on the electronic properties of the substituents of the aryl moiety and on the nature of the counterion. The enthalpies of first association of OPPh3 span -0.5 to -5 kcal mol-1 . Study of the affinity of telluroniums for OPPh3 by state-of-the-art DFT and ab-initio methods revealed the dominant Coulombic and dispersion interactions as well as an entropic effect favoring association in solution. Intermolecular orbital interactions between [Ar2 MeTe]+ cations and OPPh3 are deemed insufficient on their own to ensure the cohesion of [Ar2 MeTe ⋅ Bn ]+ complexes in solution (B=Lewis base). Comparison of Grimme's and Tkatchenko's DFT-D4/MBD-vdW thermodynamics of formation of higher [Ar2 MeTe ⋅ Bn ]+ complexes revealed significant molecular size-dependent divergence of the two methodologies, with MBD yielding better agreement with experiment.

ВИКОРИСТАННЯ ЕКСПЕРИМЕНТАЛЬНИХ ЗАВДАНЬ В КУРСІ ГЕОГРАФІЇ

The article shows the importance of creating an effective system of experimental training of future geography teachers. The main doctrine in the study of modern geography, as well as other natural science courses, is a scheme that combines a complex of theoretical and laboratory-practical means of learning phenomena in nature. Perception of theoretical propositions, their verification in practical classes and modelling during the performance of experimental tasks are equivalent in the acquisition of scientific knowledge. The components of the proposed system of forming the experimental competence of the future teacher are distinguished by their adaptability to modern educational requirements, goal-oriented organization of the training of the future specialist, and the use of a competence-oriented approach to planning the educational process. It is not possible to organize the productive training of a future teacher as an experimenter using only a traditionally organized system of experimental activity. As experience shows, it is possible to increase the efficiency of such activity only if it is complemented by an optimally organized selection system and the use of experimental tasks. Goal-oriented management of experimental training of future teachers is important under the condition of creating an educational environment based on the introduction of research educational technologies into the educational process, which are provided with appropriate methodological developments.

Application of ChatGPT for automated problem reframing across academic domains

This paper explores the potential of large language models, specifically ChatGPT, to reframe problems from probability theory and statistics, making them accessible to students across diverse academic fields including biology, economics, law, and engineering. The aim of this study is to enhance interdisciplinary learning by rendering complex concepts more accessible, relevant, and engaging. We conducted a pilot study using ChatGPT to adapt problems across 17 disciplines, evaluated through expert review. Our results demonstrate the significant potential of ChatGPT in reshaping problems for diverse settings, preserving theoretical meaning in 77.1% of cases, and requiring no or only minor revisions in 74% of cases. An evaluation performed by 23 domain experts revealed that in 73.6% of cases the reframed problem was considered to add educational value compared to a corresponding abstract problem and to represent a real-world scenario in 57.0% of cases. Furthermore, a survey involving 44 Computer Science students revealed a diverse range of preferences between original and reframed problems, underscoring the importance of considering student preferences and learning styles in the design of educational content. The study offers insights into the practicality and efficacy of employing large language models, like ChatGPT, to enhance interdisciplinary education and foster greater student engagement and understanding.

The Concept of Teleology in Kant, Hegel, and Marx

Breaking with Aristotle’s Physics, Kant effects a theoretical reconception of teleology. It is this paper’s contention that the truth of the Kantian conception of teleology as ‘a purposiveness of nature in behalf of our faculty for cognizing it’ is not that of being a solution to Hume’s problem of induction or the condition for the possibility of subjective cognition of the empirical, but that it is a theoretical means of the subjective domination over the objective. A materialist reading of Hegel’s criticism of Kant’s antinomy of teleological judgment in the Science of Logic is then proposed. Finally, the non-teleological nature of capital is demonstrated.

Accessing Indenoazulenes via a Gold‐Catalysed Cyclisation of Cycloheptatrienyl‐Substituted 1,5‐Diynes

AbstractHerein we report that cycloheptatrienyl‐substituted 1,5‐diynes with aromatic backbones undergo a gold‐catalysed 5‐endo‐dig cyclisation to give 11H‐indeno‐[2,1‐a]azulenes at room temperature. This methodology complements the established range of aromatic structures obtained from gold‐catalysed conversions of differently substituted 1,5‐diynes accessed via highly reactive cationic intermediates. We have demonstrated the scope of the reaction and have assessed the possibility of further functionalisation of the indenoazulene scaffold. Additionally, we have studied the optical and electrochemical properties as well as the frontier molecular orbitals of this structural motif by both spectroscopic and theoretical means.

Modelling of high frequency bearing voltage for dual‐winding permanent magnet synchronous generators

AbstractThe modelling and analysis of high‐frequency bearing voltage are of great significance to the assessment and mitigation of the electrical erosion risk in wind power systems. However, the dual‐winding permanent magnet synchronous generator (DW‐PMSG), as one of the mainstream models in wind power industry, has not been specifically analysed for its bearing voltage modelling method in the existing research. The high frequency common mode equivalent circuit model of DW‐PMSG is established, and the effect of parasitic parameters between two sets of winding on bearing voltage is analysed. A model parameters extraction method based on differential evolution algorithm is proposed, and the range of parameters is estimated by finite element simulation and test results, which improves the search efficiency and solution accuracy. The accuracy of the proposed model is verified by the comparison of simulation and experimental results. On this basis, it is possible to conduct more in‐depth research on the bearing voltage and bearing currents of DW‐PMSG, and provide theoretical basis and simulation means for the design of suppression schemes.

Effect of Flow on the Energy Conversion Characteristics of Multiphase Pumps Based on Energy Transport Theory

Multiphase pumps operate under different flow conditions with different work performance. In order to reveal the energy conversion regulations in multiphase pumps under different flows, this paper presents an analysis of the effects of different flows on the pressure propulsion power, Lamb vector dispersion, and vortex enstrophy dissipation in the pressurization unit of a multiphase pump based on energy transport theory. It is found that at different flows, the pressure propulsion power near the impeller inlet decreases sharply, the pressure propulsion power is mainly located in the first half of the impeller near the suction side of the blade, and with the increase in the flow, the pressure propulsion power in the pressurization unit increases gradually, as well as its energy loss, while the Lamb vector dispersion gradually increases and the area of scattering region tends to be narrow under the small impeller tip clearance, while the Lamb vector dispersion region area slowly decreases with the flow rate when the impeller tip clearance is larger. The effect of flow on the vortex enstrophy dissipation in the multiphase pump is mainly located in the middle of the impeller near the blade pressure surface, and as the flow increases, the value of the vortex enstrophy dissipation in the impeller pressurization unit increases accordingly, and the vortex enstrophy dissipation in the first half of the impeller is even more chaotic. The investigation results have significant theoretical meaning for the deep mastery of the energy conversion characteristics in multiphase pumps.

Three-Airy beams propagated in free space

We investigated propagation of three-Airy beams with or without an optical vortex in free space by theoretical, numerical and experimental means. These light fields are an object of interest for applications of modern photonics due to strong localization of the transverse intensity of the field upon propagation, self-healing and autofocusing properties.

Minimal Number of Events Required for Acceleration-Speed Profiling in Elite Women's Soccer.

To determine the minimum number of events (training or matches) for producing valid acceleration-speed (AS) profiles from global navigation satellite system (GNSS) data. Nine elite female soccer players participated in a 4-week training camp consisting of 19 events. AS profile metrics calculated from different combinations of athlete events were compared to force-velocity (FV) profile metrics from 2 × 40-m stand-alone sprint effort trials, using the same GNSS 10-Hz technology. Force-velocity profiles were calculated, from which AS profiles were obtained. AS profiles from training and matches were generated by plotting acceleration and speed points and performing a regression through the maximal points to obtain the AS metrics (theoretical maximal speed, x-intercept [in meters per second], theoretical maximal acceleration, y-intercept [in meters per second squared], and the slope per second). A linear mixed model was performed with the AS metrics as the outcome variables, the number of events as a fixed effect, and the participant identifier as a mixed effect. Dunnett post hoc multiple comparisons were used to compare the means of each number of event grouping (1-19 events) to those estimated from the dedicated sprint test. Theoretical maximal speed and theoretical maximal acceleration means were no longer significantly different from the isolated sprint reference with 9 to 19 (small to trivial differences = -0.31 to -0.04m·s-1, P = .12-.99) and 6 to 19 (small differences = -0.4 to -0.28m·s-2, P = .06-.79) events, and the slopes were no longer different with 1 to 19 events (trivial differences = 0.06-0.03s-1, P = .35-.99). AS profiles can be estimated from a minimum of 9days of tracking data. Future research should investigate methodology resulting in AS profiles estimated from fewer events.

French Phenomenology of Art and Metaphysics

Abstract This article examines the relationship between French phenomenology of art and metaphysics. More specifically, it highlights four points. Firstly, French phenomenological aesthetics is characterized by a certain ignorance of the renewal of artistic questioning initiated by Anglo-Saxon aesthetics. Secondly, French phenomenology of art is a metaphysics of art, which considers that works of art contain an ontological (cosmophanic or theophanic) revelation. Thirdly, French phenomenology of art is part of the “theological turn of French phenomenology”. Authors tend towards theology or “cosmotheology”. Fourthly, French phenomenology of art, which is a metaphysics of the sensible, possesses the theoretical means to think philosophically about conceptual art.

Constructing artificial boundary condition of dispersive wave systems by deep learning neural network

To solve one dimensional dispersive wave systems in an unbounded domain, a uniform way to establish localized artificial boundary conditions is proposed. The idea is replacing the half-infinite interval outside the region of interest with a super element which exhibits the same dynamics response. Instead of designing the detailed mechanical structures of the super element, we directly reconstruct its stiffness, mass, and damping matrices by matching its frequency-domain reaction force with the expected one. An artificial neural network architecture is thus specifically tailored for this purpose. It comprises a deep learning part to predict the response of generalized degrees of freedom under different excitation frequencies, along with a simple linear part for computing the external force vectors. The trainable weight matrices of the linear layers correspond to the stiffness, mass, and damping matrices we need for the artificial boundary condition. The training data consists of input frequencies and the corresponding expected frequency domain external force vectors, which can be readily obtained through theoretical means. In order to achieve a good result, the neural network is initialized based on an optimized spring-damper-mass system. The adaptive moment estimation algorithm is then employed to train the parameters of the network. Different kinds of equations are solved as numerical examples. The results show that deep learning neural networks can find some unexpected optimal stiffness/damper/mass matrices of the super element. By just introducing a few additional degrees of freedom to the original truncated system, the localized artificial boundary condition works surprisingly well.

Assessing model prediction performance for the expected cumulative number of recurrent events.

In a recurrent event setting, we introduce a new score designed to evaluate the prediction ability, for a given model, of the expected cumulative number of recurrent events. This score can be seen as an extension of the Brier Score for single time to event data but works for recurrent events with or without a terminal event. Theoretical results are provided that show that under standard assumptions in a recurrent event context, our score can be asymptotically decomposed as the sum of the theoretical mean squared error between the model and the true expected cumulative number of recurrent events and an inseparability term that does not depend on the model. This decomposition is further illustrated on simulations studies. It is also shown that this score should be used in comparison with a reference model, such as a nonparametric estimator that does not include the covariates. Finally, the score is applied for the prediction of hospitalisations on a dataset of patients suffering from atrial fibrillation and a comparison of the prediction performances of different models, such as the Cox model, the Aalen Model or the Ghosh and Lin model, is investigated.

ESTUDO COMPARATIVO ENTRE MÉTODOS DE ANÁLISE DA FRENTE DE CARBONATAÇÃO EM ESTRUTURAS DE CONCRETO

Being one of the most common pathological manifestations in reinforced concrete structures, carbonation can cause numerous problems in buildings, especially reinforcement corrosion. In this dynamic, the purpose of this article is to replicate a hypothetical deducible method of testing the carbonation front in reinforced concrete structures, based on an Italian model (Carbontest), having as an exploratory descriptive objective, since the main purpose was to compare the depth of the carbonation front between the “Italian” model and the current destructible method used in Brazil, so that the theoretical and practical means for obtaining data for analysis are initially presented. For the execution of the proposed model, a prototype was produced for sample collection and, from this sample, the carbonation front was determined by the pH indicator (hydrogenion potential): phenolphthalein, which provided, in comparison to the method conventional, an average variation of 2.7%, demonstrating that the application of the method of less impact is acceptable, due to the fact that it provides less destructible effect on the structures, ease of repair of the perforation and agility of the test.

Analysis of the Least Mean Square algorithm with processing delays in the adaptive arm for Gaussian inputs for system identification

This paper analyzes the effect of a processing delay on the Least Mean Squares (LMS) algorithm for a system identification problem when the processing delay is in the adaptive arm of the filter. Thus the sensing of the input signal is delayed. The input is assumed to be a zero mean stationary Gaussian process. The theoretical mean and mean square behavior of the adaptive weight vector is analyzed. The weight vector is shown to be biased and significantly affects the mean square deviation (MSD). Monte Carlo simulations are presented in support of the assumptions used to derive the theoretical model as a function of the delay, bandwidth and step-size for the LMS algorithm. The results suggest bias problems with other more complicated adaptive filtering algorithms such as Normalized LMS and Recursive Least Squares.

Do interpersonal resources improve your job performance? Scale development of interpersonal resources and the moderated mediation model of group harmony.

How to help workers establish a safe and healthy working environment is the primary purpose of promoting workplace health psychology. The aim of this study was to investigate the relationship between interpersonal resources and job performance (work performance, organizational citizen behavior). Besides, this study tries to clarify the psychological mechanisms of vitality and emotional attachment, and further considers the moderating role of group harmony. Questionnaires were used. Two samples included 267 and 285 questionnaires were collected in study 1. A total of 151 valid and matched surveys were collected in study 2. Study 1 tested the psychometric properties of the interpersonal resources scale, and then, established three constructs of interpersonal resources: "interpersonal caring", "interpersonal inclusion", and "interpersonal connection". Study 2 results showed positive correlations between interpersonal resources and job performance. Vitality has the mediating effect between interpersonal resources and work performance, and emotional attachment has the mediating effect between interpersonal resources and organizational citizen behaviors. In addition, the moderating effects of group harmony were supported. This research covered two studies to clarify the construct of interpersonal resources and develop an interpersonal resources scale with reliability and validity. Furthermore, this research further discussed the theoretical meaning and practical application and explained the future research direction. This research not only responds to experts' calls but also considers the influence of cultural values to examine the model of interpersonal resources.

On the electron impact cross-section maxima for dissociative and non-dissociative single ionization of molecules and radicals

Determining absolute electron impact ionization cross-sections for atoms and molecules, whether through experimental or theoretical means, poses a formidable challenge and is typically limited to a narrow selection of species. In this paper, by using measured cross-sections and polarizability data, it was obtained empirical scaling laws for total single ionization and non-dissociative single ionization cross-section maximum of neutral molecules by collisions with electrons. It is found that the total single ionization cross-sections scale linearly with the target electric static polarizability, while the non-dissociate cross-sections exhibit a saturation effect for large target polarizabilities. This saturation effect is interpreted as the increasing role of fragmentation with polarizability.