Model Theory Research Articles

The progression of cognitive impairment and its influencing factors in older adults based on longitudinal item response theory.

Understanding the development of cognitive impairment and its influencing factors in older adults is crucial for formulating early intervention strategies. To identify the early dimensions of cognitive impairment and provide a comprehensive description of the trajectories of cognitive decline in older adults prior to death. Based on the data of 9883 older adults in the Chinese Longitudinal Healthy Longevity Survey from 2002 to 2018, a longitudinal item response theory (Longitudinal IRT) model including covariates was applied to estimate the following parameters. The items in which older adults encountered obstacles first had the least difficulty parameters (δ). The earlier the information curve of an item is lifted, the more information it provides in the early stages of cognitive impairment. Regression coefficient (β) represents the relative rate of cognitive decline. The cognitive impairment values estimated from the Longitudinal IRT were fitted to a mixed-effects model to examine cognitive impairment trajectories. 'Draw the figure on B Card' (δ = -0.816) was the most challenging item, followed by 'recalling 'clothes" (δ = 0.348) and 'recalling 'apples" (δ = 0.419), while 'name the 'pen" (δ = 4.402) was the simplest instruction for the old adults. The curves of the items in the recall dimension began to rise in the early stages of cognitive impairment. Cognitive impairment of older adults who were women (β = 0.061), elder (β = 0.111), smokers (β = 0.060), living in rural areas (β = 0.052), not participating in organised social activities (β = 0.092), suffering from hypertension (β = 0.022), hyperglycaemia (β = 0.035), dyslipidaemia (β = 0.314), low education levels (β = 0.128), manual labourers (β = 0.027), and eventual development of dementia (β = 0.212) exhibited a more accelerated progression. These individuals also had poorer cognitive trajectories. Recall is the earliest dimension of cognitive impairment. The subjects who were women, elder, smokers, living in rural areas, not participating in organised social activities, suffering from hypertension, hyperglycaemia, dyslipidaemia, low education, manual labourers, and eventually development of dementia, had a faster descending speed and poorer trajectories.

A Numerical Analysis of the Non-Uniform Layered Ground Vibration Caused by a Moving Railway Load Using an Efficient Frequency–Wave-Number Method

The ground vibration caused by the operation of high-speed trains has become a key challenge in the development of high-speed railways. In order to study the train-induced ground vibration affected by geotechnical heterogeneity, an efficient frequency–wave-number method coupled with the random variable theory model is proposed to quickly obtain the numerical results without losing accuracy. The track is regarded as a composite Euler–Bernoulli beam resting on the layered ground, and the spatial heterogeneity of the ground soil is considered. The ground dynamic characteristics of an elastic, layered, non-uniform foundation are investigated, and numerical results at three typical train speeds are reported based on the developed Fortran computer programs. The results show that as the soil homogeneity coefficient increases, the peak acceleration continuously decreases in the transonic case, while it gradually increases in the supersonic case, and the ground acceleration spectrum at a far distance obviously decreases; the maximum acceleration occurs at the track edge, and a local rebound in vibration attenuation occurs in the supersonic case.

Learning QM/MM potential using equivariant multiscale model.

The machine learning (ML) method emerges as an efficient and precise surrogate model for high-level electronic structure theory. Its application has been limited to closed chemical systems without considering external potentials from the surrounding environment. To address this limitation and incorporate the influence of external potentials, polarization effects, and long-range interactions between a chemical system and its environment, the first two terms of the Taylor expansion of an electrostatic operator have been used as extra input to the existing ML model to represent the electrostatic environments. However, high-order electrostatic interaction is often essential to account for external potentials from the environment. The existing models based only on invariant features cannot capture significant distribution patterns of the external potentials. Here, we propose a novel ML model that includes high-order terms of the Taylor expansion of an electrostatic operator and uses an equivariant model, which can generate a high-order tensor covariant with rotations as a base model. Therefore, we can use the multipole-expansion equation to derive a useful representation by accounting for polarization and intermolecular interaction. Moreover, to deal with long-range interactions, we follow the same strategy adopted to derive long-range interactions between a target system and its environment media. Our model achieves higher prediction accuracy and transferability among various environment media with these modifications.

The Role of Art Therapy in Enhancing Rehabilitation Outcomes for Athletes with Sports Injuries

Purpose: This study sought to analyze the role of art therapy in enhancing rehabilitation outcomes for athletes with sports injuries. Methodology: The study adopted a desktop research methodology. Desk research refers to secondary data or that which can be collected without fieldwork. Desk research is basically involved in collecting data from existing resources hence it is often considered a low cost technique as compared to field research, as the main cost is involved in executive’s time, telephone charges and directories. Thus, the study relied on already published studies, reports and statistics. This secondary data was easily accessed through the online journals and library. Findings: The findings reveal that there exists a contextual and methodological gap relating to the role of art therapy in enhancing rehabilitation outcomes for athletes with sports injuries. Preliminary empirical review revealed that art therapy offers significant benefits for athletes recovering from sports injuries. Through a review of empirical studies, it was found that art therapy facilitated emotional expression, coping skills development, and social support, leading to improved psychological well-being and holistic healing. The study emphasized the importance of addressing the biopsychosocial aspects of rehabilitation and highlighted the need for further research to understand the mechanisms underlying the therapeutic effects of art therapy. Overall, the findings underscored the transformative potential of art therapy in optimizing rehabilitation outcomes for athletes with sports injuries. Unique Contribution to Theory, Practice and Policy: Biopsychosocial Model of Health, Self- Determination theory (SDT) and Transactional Model of Stress and Coping may be used to anchor future studies on rehabilitation for athletes with sports injuries. The study provided several recommendations contributing to theory, practice, and policy in sports injury rehabilitation. It suggested further exploration of theoretical frameworks to understand art therapy's therapeutic mechanisms and its integration into existing models. In practice, it recommended incorporating art therapy into multidisciplinary rehabilitation programs, along with developing evidence-based guidelines for its implementation. Additionally, the study advocated for policy initiatives to increase access to art therapy services for athletes, emphasizing collaboration among stakeholders and interdisciplinary knowledge sharing. These recommendations aimed to promote holistic approaches to rehabilitation, improve outcomes, and enhance the overall well-being of injured athletes.

The transition from physical sibling abuse to bullying perpetration through trait anger: A longitudinal study.

Experiencing physical sibling abuse is a form of family violence that is common but understudied. While it is often perceived as a normative aspect of sibling relationships, there are apparent behavioral consequences. The current study aims to advance the literature by utilizing the displaced aggression model and I3 theory to longitudinally examine trait anger as a pathway linking physical sibling abuse to bullying perpetration. Using data from the Bullying, Sexual, and Dating Violence Trajectories from Early to Late Adolescence in the Midwestern United States, 2008-2013, adolescents (n = 851, M = 14.8 years) completed questionnaires at baseline and were reassessed 6 months later. Results suggested that when adolescents experience physical sibling abuse, they are more likely to engage in bullying perpetration. Mediation analyses indicated that as adolescents were physically abused by a sibling at home, they were more likely to report higher levels of trait anger, which subsequently increased their risk of engaging in bullying perpetration. These results suggest that experiencing physical sibling abuse has long-term detrimental consequences, including elicitation of trait anger, subsequently predicting bullying perpetration.

Analysis of Unmanned Aerial Vehicle-Assisted Cellular Vehicle-to-Everything Communication Using Markovian Game in a Federated Learning Environment

The paper studies a game theory model to ensure fairness and improve the communication efficiency in an unmanned aerial vehicle (UAV)-assisted cellular vehicle-to-everything (C-V2X) communication network using Markovian game theory in a federated learning (FL) environment. The UAV and each vehicle in a cluster utilized a strategy-based mechanism to maximize their model completion and transmission probability. We modeled a two-stage zero sum Markovian game with incomplete information to jointly study the utility maximization of the participating vehicles and the UAV in the FL environment. We modeled the aggregating process at the UAV as a mixed strategy game between the UAV and each vehicle. By employing Nash equilibrium, the UAV determined the probability of sufficient updates received from each vehicle. We analyzed and proposed decision-making strategies for several representative interactions involving gross data offloading and federated learning. When multiple vehicles enter a parameter transmission conflict, various strategy combinations are evaluated to decide which vehicles transmit their data to the UAV. The optimal payoff in a transmission window is derived using the Karush–Khun–Tucker (KKT) optimality conditions. We also studied the variation in optimal model parameter transmission probability, average packet delay, UAV transmit power, and the UAV–Vehicle optimal communication probabilities under different conditions.

Computation of the near-infrared electro-absorption in GeSn/SiGeSn step quantum wells

In this study, we propose a theoretical simulation of the type-I step quantum well obtained from GeSn/SiGeSn to scan a wide range of telecommunication wavelengths and obtain near-infrared optical modulators. At T = 300 K, the band discontinuities and energy gap between stretched Ge1−xSnx and relaxed Si0.1Ge0.9−ySny due to the acquisition of the heterostructure were calculated.Then, optimization of this heterostructure based on (Si) GeSn was performed using the solid theory model to balance out the composition y of Si0.1Ge0.9-ySny relaxed and thickness of Ge0.91Sn0.09 QWs. The eigenenergies and their related wavefunctions are computed by solving the Schrödinger equation using the finite difference method under the framework of the effective mass approximation. Depending on the y concentration, the energy levels of the electron and the heavy hole, the change of transition energies and oscillator strength were examined for different well widths. Additionally, the absorption coefficient with y concentration and structure parameters were examined.From the findings obtained, it was determined that this material group is very important to obtain high efficiency from electro-absorption modulators covering the 1.55 μm wavelength range.

Real Virtuality and Actual Transitions: Historical Reflections on Virtual Entities before Quantum Field Theory

Abstract This paper studies the notion of virtuality in the Bohr-Kramers-Slater theory of 1924. We situate the virtual entities of BKS within the tradition of the correspondence principle and the radiation theory of the Bohr model. We show how, in this context, virtual oscillators emerged as classical substitute radiators and were used to describe the otherwise elusive quantum transitions. They played an effective role in the quantum theory of radiation while remaining categorically distinct and ontologically separated from the quantum world of the Bohr model. The notion of virtuality thus differs markedly from its counterpart in quantum mechanics or QFT.

Random Vibration Fatigue Life Prediction of Nano-Silver Solder Joint

Nano-silver is a very potential electronic interconnection material. It’s excellent physical and chemical properties, high thermal conductivity and good electrical conductivity make it very suitable for high power electronic devices. In practical engineering, 20% of the failure of electronic products is caused by vibration load, so it is necessary to study the vibration reliability of interconnected materials. In this paper, the modal and random vibration finite element analysis of nano-silver solder joints were analyzed with workbench software. Predicting random vibration fatigue life of nano-silver solder joint by Coffin-Manson high cycle fatigue empirical formula, Miner’s linear cumulative damage theory and Steinberg model. The random vibration fatigue life of the nanosilver solder joint is 8342 h. It is found that the vibration reliability of nano-silver is inferior to Sn3.0Ag0.5Cu and Sn63Pb37 and the diameter of solder joints and PCB thickness are proportional to the vibration fatigue life, and the PCB thickness has a greater effect on the vibration life than the solder joint diameter. Solder joint height and pad thickness are inversely proportional to vibration fatigue life, and pad thickness has little effect on vibration fatigue life.

A Study on Passengers’ Acceptance of Untact Technology Services at Incheon Airport: Application Innovative Expansion Theory and Technology Acceptance Model

A Study on Passengers’ Acceptance of Untact Technology Services at Incheon Airport: Application Innovative Expansion Theory and Technology Acceptance Model

Impact of Broadcaster's Social Presence and Ad Content Persuasiveness on Impulsive Purchase Behaviour in China Live Streaming: A Mediation Analysis of Arousal and Emotion

The rapid rise of live streaming in China has revolutionized digital communication and e-commerce, merging entertainment with instant consumer interaction. This study delves into the impact of suggestive advertising on impulsive buying behavior within the Chinese live-streaming market, employing the Elaboration Likelihood Model and Emotional Response Theory to analyze viewers' cognitive and emotional processing. Through a mixed-method approach combining quantitative surveys with qualitative interviews, this research captures insights from Beijing and Shanghai to explore how live streaming influences consumer behavior. Key findings indicate that suggestive advertising effectively triggers impulsive purchases, particularly when mediated by broadcasters' social presence and emotional engagement. This study highlights the nuanced interplay between technology, advertising strategies, and consumer psychology in shaping modern buying habits.

Exploring electron transfer: Bioinspired, biomimetics, and bioelectrochemical systems for sustainable energy and Value-Added compound synthesis

Electron transfer (ET) is a fundamental process that underlies various phenomena in physics, chemistry, and biology. Understanding ET mechanisms is crucial for developing sustainable energy solutions and synthesizing value-added compounds efficiently. In this context, the present review provides the fundamental aspects of ET involving bioinspired, biomimetics, and biological entities and its significance for sustainable energy and green electrosynthesis fields. Among the theoretical and experimental cornerstones, Marcus Theory, electronic conductance, computational modeling, biomolecular thermodynamics, electrochemical and kinetic theories, protein film voltammetry, and the emergence of in situ and operando techniques are explored. Theoretical modeling is vital for understanding and predicting ET processes. Additionally, the significance of experimental techniques for investigating the ET process in biological entities and interfaces is discussed. Protein film voltammetry is a valuable and consolidated technique for studying ET processes at the protein-electrode interface, whereas in situ and operando techniques for interrogating ET processes in real time provide insights into the dynamics and mechanisms of ET. The concept of quantum conductance in biological structures is addressed, evidencing a trend and power of single-entity analysis. Aspects of extracellular and interfacial ET processes are presented and discussed in the electrochemical energy conversion systems. A deep understanding of these processes can improve the design of efficient bioinspired catalysts. Therefore, this multidisciplinary work aims to fill the gaps between different scientific fields related to ET involving bioentities to develop innovative energy and value-added compound synthesis solutions.

Impact of Broadcaster's Social Presence and Ad Content Persuasiveness on Impulsive Purchase Behaviour in China Live Streaming: A Mediation Analysis of Arousal and Emotion

The rapid rise of live streaming in China has revolutionized digital communication and e-commerce, merging entertainment with instant consumer interaction. This study delves into the impact of suggestive advertising on impulsive buying behavior within the Chinese live-streaming market, employing the Elaboration Likelihood Model and Emotional Response Theory to analyze viewers' cognitive and emotional processing. Through a mixed-method approach combining quantitative surveys with qualitative interviews, this research captures insights from Beijing and Shanghai to explore how live streaming influences consumer behavior. Key findings indicate that suggestive advertising effectively triggers impulsive purchases, particularly when mediated by broadcasters' social presence and emotional engagement. This study highlights the nuanced interplay between technology, advertising strategies, and consumer psychology in shaping modern buying habits.

The impact mechanism of telework on job performance: a cross-level moderation model of digital leadership

Traditional enterprise management believes that telecommuting activities are out of the enterprise's control, which may reduce staff performance. We use the extension of job demand-resource theory and work embeddedness theory to develop and test the intermediary mechanism of embedded in and out of work in telework. Moreover, it judges the mediating effect of job embeddedness on telecommuting → job performance. With the help of family conflict theory, we have revealed the possible performance changes in telework and the impact of family on telework. We predict embedding outside of work may reduce job performance. However, this worry will not happen under the adjustment of digital leadership and job insecurity. We collected survey data from 36 enterprise teams and 328 members. We have confirmed that work performance will not be reduced by telecommuting. Digital leadership magnifies the embedding of telecommuting resources into employees’ work to a certain extent and inhibits the embedding problem outside work caused by telecommuting requirements. The telecommuting requirement may become a positive factor for employees staying home and avoiding workplace conflicts. We confirmed the inhibitory effect of job embeddedness on turnover rate and expanded the antecedent model of job embeddedness theory.

A modified Green-Naghdi fractional order model for analyzing thermoelectric MHD

PurposeWhereas, the classical Green-Naghdi Type II (GN-II) model struggles to accurately represent the thermo-mechanical behavior of thermoelectric MHD due to its inability to account for the memory effect. A new mathematical model of the GN-II theory incorporates a fractional order of heat transport to address this issue.Design/methodology/approachThe employment of the matrix exponential method, which forms the basis of the state-space approach in contemporary theory, is central to this strategy. The resulting formulation, together with the Laplace transform techniques, is applied to a variety of problems. Solutions to a thermal shock problem and to a problem of a layer media both without heat sources are obtained. Also, a problem with the distribution of heat sources is considered. The numerical technique is used to achieve the Laplace transform inversion.FindingsAccording to the numerical results and its graphs, the influences of the fractional order parameters, figure-of-merit factor, thermoelectric power and Peltier coefficient on the behavior of the field quantities are investigated in the new theory.Originality/valueThe new modeling of thermoelectric MHD has advanced significantly as a result of this work, providing a more thorough and precise tool for forecasting the behavior of these materials under a range of thermal and magnetic conditions.

Page curve of AdS-Vaidya model for evaporating black holes

We study an evaporating black hole in the boundary conformal field theory (BCFT) model under the fully time-dependent AdS-Vaidya spacetime geometry. We introduce the time-dependent finite bath termed the effective Hawking radiation region. This is described by a nontrivial BCFT solution that acts as a time-dependent brane which we call the moving end-of-the-radiation (METR) brane that leads to a new type of Hubeny-Rangamani-Takayanagi surface. We further examine the island formulation in this particular time-dependent spacetime. The Page curve is calculated by using Holographic Entanglement Entropy (HEE) in the context of double holography.

Investigating the Educational and Social Factors Affecting Saudi EFL Learners' Attitudes toward Learning English

This study aims to investigate the attitude of Saudi EFL learners toward learning English as a foreign language, their motivation, and contextual and surrounding factors affecting their attitudes positively or negatively. Out of the population that comprises students studying in levels 1 & and 2 of the graduate programs at Business College, PSAU, 216 EFL learners of Saudi Arabia were selected through a simple random sampling method. A self-designed questionnaire with partial adoption of modified items from existing studies was sent to the students to collect their responses. The quantitative approach (descriptive quantitative design) revealed that Saudi EFL students typically exhibited a high level of positivity toward English as a foreign language, and they demonstrated a high level of instrumental motivation but a lower level of integrative motivation toward English. The use of Spolsky’s (1969) and Gardner’s (1985) Second Language Learning Model and Second Language Acquisition theories respectively revealed that certain educational and social factors (e.g., English learning situation, language teachers, and parents) had an advantageous effect on Saudi EFL learners. In the same way, different social and educational factors, such as peer groups, educational settings, and educational environments, have been found negatively impacting learners' motivation and their desire to speak or learn the language. The study implies that the factors (learning physical environment, teaching material, peer groups) affecting the learners’ attitude negatively should be improved. The study would be beneficial to instructors and students in understanding the elements that impede language acquisition and assist them in attaining outstanding and effective English skills.

Hot deformation behavior and processing map of vanadium particles reinforced AZ31 composite

The vanadium particles reinforced AZ31 matrix composite (VP/AZ31) was prepared using the powder metallurgy method. Subsequently, hot deformation behavior of VP/AZ31 composite was studied through hot compression trials. The experimental parameters were set in a temperature range of 250–400 °C and a strain rate range of 0.001–1 s−1. Based on the experimental results, a strain-compensated Arrhenius constitutive model was developed to accurately forecast the flow behavior of VP/AZ31 composite. Moreover, the thermal activation energy was calculated to be 138.605 kJ/mol and the processing map was delineated according to the dynamic material model theory. The processing map revealed that the optimal processing area existed under 363–400 °C/0.001–0.004 s−1, where the efficiency of power dissipation exceeded 23 %. Notably, the highest efficiency of power dissipation occurred at 400 °C/1 s−1, which exceeded 30 %. Under these conditions, dynamic recrystallization (DRX) was sufficiently developed, indicating the enhancement of workability. It is estimated that the instability region for VP/AZ31 composites occurred within the conditions of 250–325 °C/0.16–1 s−1, characterized by crack formation. The DRX of VP/AZ31 composite is predominantly governed through the mechanism of discontinuous DRX (DDRX).

Validation of the Chinese version of the Oslo-3 Social Support Scale among nursing students: a study based on Classical Test Theory and Item Response Theory models

BackgroundNursing students are encountering a range of health issues. Assessing social support is a key component in most questionnaire surveys related to health status, aiming to investigate the relationships and mechanisms between health status and social support to enhance overall health. Therefore, it is essential to seek out appropriate instruments to evaluate social support for nursing students. The Oslo-3 Social Support Scale (OSSS-3) is a reliable and concise instrument for evaluating social support. To date, there have been no studies validating the OSSS-3 based on Item Response Theory (IRT) models. Also, an officially validated Chinese version has not been found. The current research intended to verify the Chinese version of the OSSS-3.MethodsThe OSSS-3 was translated into Chinese and culturally adapted. Subsequently, the OSSS-3 was validated by employing the Classical Test Theory (CTT) and IRT models.ResultsThe split-half reliability was 0.622. The Cronbach’s α coefficient was 0.687. The correlations between each item and total scores varied from 0.723 to 0.835. The retest coefficient was 0.907. The content validity index was 0.933. A single common factor was extracted and accounted for 61.559% of the variance. The item loading values on the single factor were between 0.743 and 0.814. The communalities were between 0.552 and 0.663. There was no variance between males and females (P = 0.055). The difference in scores between the top (30%) and bottom (30%) groups attained significance. IRT models results revealed that the discrimination parameters ranged from 1.39 to 2.33 and difficulty parameters increased monotonically.ConclusionThe OSSS-3 demonstrates satisfying psychometric properties and is a proper instrument for measuring social support in Chinese nursing students.

Advanced Thick FGM Plates-Cylindrical Shells in Linear Unsteady Supersonic Flow

Introduction:: Thick functionally graded (FG) plates-cylindrical shells with third-order shear deformation theory (TSDT) of displacement models under thermal vibration in linear unsteady supersonic flow are investigated by using the generalized differential quadrature (GDQ) method. Method:: The nonlinear coefficient term of TSDT models and the advanced nonlinear shear correction coefficient expression are used to study the thermal vibration of thick FG plates and cylindrical shells in linear unsteady supersonic flow. At the intersection of FG plates-cylindrical shells, the displacements, stress resultants, and moment resultants could be reasonably assumed in the continuity condition for the differential volume in linear unsteady supersonic flow, respectively. Result:: The dynamic equilibrium differential equations of thick FG plates and cylindrical shells in linear unsteady supersonic flow, respectively in terms of partial derivatives of displacements and shear rotations subjected to partial derivatives of thermal loads, mechanical loads consist of the linear supersonic aerodynamic pressure and inertia terms can be presented. Two parametric effects including environment temperature and functionally graded material (FGM) power law index on the thermal stress and center displacement of thick FG plates-cylindrical shells in linear unsteady supersonic flow are investigated. Conclusion:: The linear unsteady supersonic flow over the outer surface of thick FG platescylindrical shells provides the additional aerodynamic effect on the values of displacements and stresses.