Theory Modeling Research Articles

TEACHING COMPUTER MODELING TO INFORMATION TECHNOLOGY STUDENTS: A PRACTICE-ORIENTED APPROACH

A structural model of modeling competence in information technology education is presented, which includes three main elements: subject-specific knowledge; meta-knowledge about models and simulation and modeling practice. The structural model of modeling competence develops the theory and methodology of teaching modeling to schoolchildren. A survey of experts was conducted, which showed high perceived usefulness, ease of use, and behavioral intention to use the proposed modeling competency model for information technology classes.

Implementation of Innovative Technologies During the Modernization of Existing Level Crossings for High-Speed Train Traffic

Implementation of Innovative Technologies During The Modernization of Existing Level Crossings for High-Speed Train Traffic Purpose. The main purpose of the study is to review innovative technologies for improving safety at the intersection of railways and roads. The object of research is the processes of functioning – railway crossings with different intensity and parameters of traffic, which require solving a fairly wide range of theoretical, practical and organizational tasks. Methodology. The study is based on the theory of mathematical modeling and numerical methods of computer calculations. The subject of the study is indicators that allow to assess the state of safety after modernization or new design solutions. Findings. A model of an improved method of the final coefficient is proposed, which allows predicting changes in the initial data and obtaining different values of the final coefficient, and thus planning measures to introduce innovative technologies that improve traffic safety at level crossings. Closing railroad crossings or switching to a two-level intersection of railroad and road (overpasses) is the only way to completely eliminate the risk. However, it is virtually impossible to close all railroad crossings immediately. In addition to financial and practical constraints, user convenience should still be a key factor. Using hierarchy, brainstorming, and other methods, a reliable set of indicators can be identified to assess and ensure the overall safety of passengers and vehicles related to all aspects of the design, construction, maintenance, and operation of the rail network. The introduction of innovative technologies during the modernization of existing level crossings is an important step towards organizing high-speed train traffic. These technologies will increase the level of traffic safety at railroad crossings and protect people's lives. Originality. The scientific and applied problem of introducing innovative technologies during the modernization of existing level crossings for the organization of high-speed train traffic has been solved. Practical value. The implementation of a sound technology for the modernization of existing level crossings will provide a significant increase in traffic safety and throughput.

Analysis of blockchain introduction strategies in maritime business with game theory modelling

In the last years the blockchain technology has attracted the focus of many companies in maritime business, due to its potential to make a revolution in this field. This technology became especially important in supply chains, where it offers the possibility to increase the transportation effectiveness. It is shown that currently there is no instrument to analyze the strategies on blockchain technology introduction in maritime shipping. In order to solve this problem, it is suggested to use game theory models, which allows you to simulate the relationships among maritime shipping participants. In order to create a model of such type, the description of main participants is represented in the paper and the main schemes of their interaction are analyzed. The structured schemes of the participants introduction, during the organization of maritime shipping in a traditional form and with the utilization of blockchain are suggested in the paper. The structure of basic game theory model of maritime shipping is shown. In order to show the possibilities of the analysis using the proposed model four experiments are considered. The first one is the traditional form of participants interaction. The second one is the interaction of participants fully through the blockchain. The third one is the change of attitude to blockchain depending on economic efficiency. The fourth one is the gradual introduction of blockchain technology. The results show the change of economical effectiveness of business participants in different cases. It is shown in the paper that the introduction of blockchain allows to speed up a company cash-flow, which makes the business management much easier. It is also proved that the suggested model must be improved with introduction of new conditions and motives of the participants.

Probabilistic notch fatigue assessment under size effect using micromechanics-based critical distance theory

Geometrical discontinuities are inevitable in engineering structures due to various functional requirements, which often yield complex stress–strain state and thereby significantly impact their fatigue performances. In this study, crystal plasticity theory is coupled with traditional critical distance theory for notch effect modelling considering microstructural heterogeneity. Specifically, microstructural and geometrical size effects on critical distance and fatigue performance are studied based on Sub-modelling approach. In addition, critical distance theory is coupled with Weibull distribution for probabilistic fatigue life evaluation of notched components. The developed method is verified and compared by using experimental data of GH4169 alloy. The findings demonstrate that the evaluated P-S-N curves exhibit strong agreement with tested data and geometrical size effect poses larger influence than the grain size effect on critical distance and fatigue life.

Reclaiming Logic Modeling for Evaluation: A Theory of Action Framework

Logic modeling, the process that explicates how programs are constructed and theorized to bring about change, is considered to be standard evaluation practice. However, logic modeling is often experienced as a transactional, jargon-laden, discrete task undertaken to produce a document to comply with the expectations of an external entity, the consequences of which have minimal or even negative influence on the quality of program evaluation. This article presents the Logic Modeling Theory of Action Framework (LMTAF) which elucidates needs, resources, and central activities of logic modeling, and describes its potential evaluation-related benefits. The LMTAF situates evaluators as the primary intended users of logic modeling, and logic modeling as a fundamental element of each stage of a program evaluation life cycle. We aim to reassert the value of logic modeling for evaluation and provide evaluation practitioners a useful touchstone for reflective practice and future action.

Item response theory analysis of daytime sleepiness as a symptom of obstructive sleep apnea.

Obstructive sleep apnea (OSA) is a sleep disorder which is linked to many health risks. The gold standard to evaluate OSA in clinical trials is the Apnea-Hypopnea Index (AHI). However, it is time-consuming, costly, and disregards aspects such as quality of life. Therefore, it is of interest to use patient-reported outcomes like the Epworth Sleepiness Scale (ESS), which measures daytime sleepiness, as surrogate end points. We investigate the link between AHI and ESS, via item response theory (IRT) modeling. Through the developed IRT model it was identified that AHI and ESS are not correlated to any high degree and probably not measuring the same sleepiness construct. No covariate relationships of clinical relevance were found. This suggests that ESS is a poor choice as an end point for clinical development if treatment is targeted at improving AHI, and especially so in a mild OSA patient group.

Comparison of classical beam theory and finite element modelling of timber from fibre orientation data according to knot position and loading type

Comparison of classical beam theory and finite element modelling of timber from fibre orientation data according to knot position and loading type

A Brief Review of Recent Theoretical Advances in Fe-Based Catalysts for CO2 Hydrogenation.

Catalytic hydrogenation presents a promising approach for converting CO2 into valuable chemicals and fuels, crucial for climate change mitigation. Iron-based catalysts have emerged as key contributors, particularly in driving the reverse water-gas shift and Fischer-Tropsch synthesis reactions. Recent research has focused on enhancing the efficiency and selectivity of these catalysts by incorporating alkali metal promoters or transition metal dopants, enabling precise adjustments to their composition and properties. This review synthesizes recent theoretical advancements in CO2 hydrogenation with iron-based catalysts, employing density functional theory and microkinetic modeling. By elucidating the underlying mechanisms involving metallic iron, iron oxides, and iron carbides, we address current challenges and provide insights for future sustainable CO2 hydrogenation developments.

Habitat suitability and connectivity modelling predict a latitudinal-driven expansion in the Mediterranean basin for a historically introduced reptile

Species introductions outside their native ranges, often driven by trade and other anthropogenic activities, present significant ecological challenges. Reptiles, frequently traded as pets for their attractiveness, are particularly susceptible to such introductions, leading to shifts in distribution patterns and potential ecological impacts. The common chameleon (Chamaeleo chamaeleon), which has been historically introduced in several European countries, is such an example, yet no overall assessments are available to date for this species. In this study, we used ecological niche models to assess habitat suitability for the common chameleon in the Mediterranean basin for current and future scenarios. Concurrently, circuit theory techniques were employed to evaluate habitat connectivity in two historically introduced areas. We identified areas of high habitat suitability and dispersal corridors in introduced regions. Our results reveal a latitudinal gradient in habitat suitability changes, with the species facing both expansion and decline in different parts of its range, depending on the ecozone considered. Severe declines are noted in southeastern Spain, Tunisia, and Israel, while habitat suitability increases westwards in Portugal, Morocco, and Southern Italy. These insights contribute to a better understanding of the common chameleon’s ecological dynamics, providing a foundation for targeted management and conservation efforts. Our study highlights the importance of integrating ecological niche modelling and circuit theory techniques to predict habitat suitability and identify critical dispersal corridors for effective conservation strategies. Considering the ongoing challenges posed by human-mediated dispersals for the common chameleon, our research establishes a foundation for future studies to enhance our understanding of this elusive species.

Palladium Metal Nanocomposites Based on PEI-Functionalized Nitrogen-Doped Graphene Quantum Dots: Synthesis, Characterization, Density Functional Theory Modeling, and Cell Cycle Arrest Effects on Human Ovarian Cancer Cells.

In this study, the synthesis, characterization, density functional theory calculations (DFT), and effect of polyethylenimine (PEI)-functionalized nitrogen-doped graphene quantum dots (PEI N-GQDs) and their palladium metal nanoparticles nanocomposites (PdNPs/PEI N-GQDs) on cancer cells were extensively investigated. The focus also includes investigating their cytotoxic and apoptotic effects on ovarian cancer cells, which pose a serious risk to women's health and have high death rates from delayed diagnosis, inadequate response to treatment, and decreased survival. Graphene quantum dots and their palladium nanocomposites were differentially effective against ovarian cancer cell lines. In particular, the smaller particle size and morphology of PdNPs/PEI N-GQDs nanocomposites compared with PEI N-GQDs probably enhance their activity through highly improved uptake by cells. These findings emphasize the importance of particle size in composite drugs for efficient cancer treatment. DFT results revealed that the Pd-containing nanocomposite, with a smaller highest occupied molecular orbital-lowest unoccupied molecular orbital gap, exhibited higher reactivity and anticancer effects in human ovarian cancer cell line, OVCAR-3. Significantly, the application of nanocomposites to ovarian cancer cells initiated apoptosis, offering valuable insights into the intricate interplay between nanomaterials and cancer biology.

Construct validity, responsiveness, minimal detectable change, and minimal clinically important difference of the stroke self-efficacy questionnaire in individuals receiving stroke rehabilitation

Purpose To assess the clinimetric properties of the Stroke Self-Efficacy Questionnaire (SSEQ) and estimate the minimal detectable change (MDC) and minimal clinically important difference (MCID) from the database of our randomized controlled trials (RCT) of individuals receiving stroke rehabilitation. Methods We retrieved the pre- and post-intervention scores of the SSEQ and Stroke Impact Scale (SIS) from 80 stroke survivors. The analysis of clinimetric properties was performed using: (1) confirmatory factor analysis and item response theory modeling (IRT) for construct validity; (2) standardized response mean and Glass’s delta for responsiveness; (3) MDC based on the standard deviation (SD) or standard error of measurement (SEM) of the SSEQ change scores; (4) MCID determined by the external anchor–SIS; (5) conditional MDC (cMDC) derived from the IRT analysis. Results There was a bi-factorial construct with excellent model-data fit and marked responsiveness. The MDC determined by the SD and SEM were 1.5 and 3.0, respectively, and the MCIDs were 3.3 and 3.7. Conclusions This study confirmed that SSEQ is a valid and reliable assessment tool for patients receiving stroke rehabilitation. We also provided practical threshold values, especially demonstrating the benefit of using individualized cMDC, to help clinicians better interpret the change in the SSEQ scores.

Retraction: “Modeling of plasma wave propagation and crystal lattice theory based on computational simulations” [AIP Adv. 13, 045223 (2023)

Retraction: “Modeling of plasma wave propagation and crystal lattice theory based on computational simulations” [AIP Adv. 13, 045223 (2023)

Modified rhyme test performance and error patterns predict self-reported frequency of temporary threshold shifts for normal hearing listeners

After exposure to a loud sound, listeners may report that their hearing is dull or muffled. If hearing returns to pre-exposure levels, the change is considered a temporary threshold shift (TTS). TTSs are likely associated with damage to the auditory system. How frequently TTSs are experienced has been shown to be related to performance deficits on tasks like the modified rhyme test (MRT), even if audiometric thresholds are normal. The present study seeks to better understand the types of phonetic errors listeners with different frequencies of TTSs make on the MRT. Over 4000 US Service Members (SMs) completed the study. SMs were asked how frequently they experienced a TTS: “Never,” “Infrequent” ( < 1/year), or “Frequent” (≥1/ year). SMs completed 80 trials of a version of the MRT where SNR and target level were manipulated. Responses were analyzed using information theory and statistical modeling. Overall proportion correct, reaction time, and error rates associated with phonetic features were predictors of TTS frequency for normal hearing listeners. [The views expressed in this abstract are those of the authors and do not necessarily reflect the official policy of the Department of Defense or the U.S. Government.]

Gestalt Modeling of Ponteio No. 28 by Camargo Guarnieri

Abstract: In this work, the analytical-compositional methodology called Gestalt Modeling (hereinafter GM) is used to analyze Camargo Guarnieri’s Ponteio No. 28 , from the perspective of three laws of perceptual organization according to Gestalt Psychology. The objective of the analysis is to provide some definitions of the hypothetical system that generated this musical work by Guarnieri and to plan a musical composition for solo piano entitled Aboio . This planning will be described in detail in this paper. GM comes from the convergence between two fields of knowledge, Gestalt Theory and Systemic Modeling, whose definitions will be introduced in this work. From the structural dispositions of an intertext (a pre-existing musical work), according to certain Gestalt laws of perceptual organization, it is possible to create new works based on these structures. GM basically consists of two phases: 1) analysis from the perspective of Gestalt Theory; and 2) relational generalization, which consists of considering only the relationships between objects detected in the analytical phase, disregarding their particular values. The result of this methodology is a hypothetical compositional system that generates the work used in the planning of the new work Aboio . There are aesthetic similarities at a deep level between this work and the intertext, and there are significant differences related to aspects not included in the compositional system and to the filling of relational structures contained in the system. As final results, GM presents itself as: 1) a useful and differentiated resource for the analysis of musical works and also for compositional purposes, for coherently presenting new ways of organizing musical elements; and 2) possible methodology for compositional pedagogy as it provides subsidies for a conscious practice and the development of the student’s own compositional language.

Graph modeling of relational structures among functioning variables with low back pain: an exploratory analysis based on International Classification of Functioning, Disability and Health.

Given the complex etiology, multidimensional impact, and widespread prevalence of low back pain (LBP), it is crucial to prioritize intervention targets based on understanding the relationships between functional impairments in patients. This prioritization maximizes the physical and psychological benefits for patients, and graph modeling holds promise in achieving these objectives. The aim of this study was establishing a graphical model of functioning variables for LBP based on the International Classification of Functioning, Disability, and Health (ICF) to identify the most influential items (i.e., functioning variables) on the physical and mental well-being of patients. Exploring feasible intervention measures by understanding the dysfunction correlations among these variables. Cross-sectional survey. Nine hospitals in Jiangsu Province, China. Three hundred and six persons with LBP aged ≥18 years. All patients were assessed using the Comprehensive ICF Core Sets for LBP. The scoring system was converted to dichotomous data, with 1 indicating dysfunction and 0 indicating no dysfunction. In the graphical model, network parameters and the results of Item Response Theory modeling (as detailed in our other article) were used to determine the importance of items, while partial correlations were utilized to estimate the dysfunction correlations between functioning variables. 1) A total of 56 ICF items were located in the backbone structure of LBP, among which d430 (Lifting and carrying objects) occupied the most central position, followed by b126 (Temperament and personality functions). 2) In the main component of backbone structure, d430 has moderate dysfunction correlation with looking after one's health (0.6027), social norms, practices and ideologies (0.597), stability of joint functions (0.5759), and emotional functions (0.4078). b126 has moderate dysfunction correlation with basic interpersonal interactions (0.6595). d430 and b126 significantly impact the physical and mental well-being of LBP patients. To improve d430, maintaining exercise habits, reducing working hours, enhancing lumbar stability, and overcoming fear-related emotions are recommended. Similarly, improving b126 can be achieved through enhancing interpersonal relationships. Through the identification of crucial functioning variables and the associated dysfunctional correlation relationships, graphical model of Comprehensive ICF Core Set for LBP can offer healthcare decision-makers valuable insights into potential treatment targets and pathways aimed at improving the condition of LBP patients.

Thermoelectric Properties of Porphyrin Nano Rings: A Theoretical and Modelling Investigation.

Propagation of De Broglie waves through nanomolecular junctions is greatly affected by molecular topology changes, which in turn plays a key role in determining the electronic and thermoelectric properties of source|molecule|drain junctions. The probing and realization of the constructive quantum interference (CQI) and a destructive quantum interference (DQI) are well established in this work. The critical role of quantum interference (QI) in governing and enhancing the transmission coefficient T(E), thermopower (S), power factor (P) and electronic figure of merit (ZelT) of porphyrin nanorings has been investigated using a combination of density functional theory (DFT) methods, a tight binding (Hückel) modelling (TBHM) and quantum transport theory (QTT). Remarkably, DQI not only dominates the asymmetric molecular pathways and lowering T(E), but also improves the thermoelectric properties.

Using Consumer-Generated Social Media Posts to Improve Forecasts of Television Premiere Viewership: Extending Diffusion of Innovation Theory

This research investigated how social media can be quantified and used as an input to improve audience forecasts for television show premieres. There were two key findings. First, Twitter activity (volume of tweets and retweets) drives viewership of shows that are unscripted (i.e., reality or competition shows). From a practical perspective, Twitter activity improved prediction accuracy beyond that of forecasting inputs typically employed by the industry. The second key finding was the interaction of media attention given to a show and audience size of the show leading into (i.e., preceding) the premiere. One practical implication for network scheduling and promotion efforts is to use strong lead-in shows along with large mass media efforts for a television season’s “flagship” series that are most important for a network’s success. This research also extends Diffusion of Innovation theory (Rogers, 2003) and diffusion modeling to television entertainment consumption. Diffusion of Innovation theory predicts the importance of information dispersion across heterophilous groups (i.e., groups that are diverse). The Bass (1969) diffusion model, a statistical model introduced to describe the diffusion of innovation, also predicts that media presence (an external factor) in conjunction with consumer eWOM (an internal factor) drive premiere ratings.

PKa as a Predictive Descriptor for Electrochemical Anion Adsorption

AbstractThe adsorption of anions onto metal surfaces is important in many applications including effective (electro)catalyst design, metal surface modification, and contaminant removal in wastewater treatment. In electrocatalysis, anions can be both reactive intermediates or site‐blocking spectators, where their adsorption strength therefore dictates the rate of reaction. In this work, we have measured the adsorption energy of a series of carboxylic acids on a Pt (111) single‐crystal electrode surface from aqueous solution. We find that the adsorption strength of the carboxylate anion is linearly correlated with its acid‐dissociation constant (pKa) and therefore the heterolytic O−H bond dissociation strength in solution. Using density functional theory modeling, we split the anion adsorption energy into a sum of the adsorption energy and electron affinity of a neutral (carboxyl) radical. Surprisingly, the adsorption energy of the carboxyl radicals are similar and therefore the large difference in electron affinity is what dictates anion adsorption strength; the greater the cost in energy to remove the electron from the anion upon adsorption, the weaker its binding. Therefore, at least within a class of anions with similar structure and surface binding atoms, both electron affinity and acidity are predictive descriptors of adsorption strength.

PKa as a Predictive Descriptor for Electrochemical Anion Adsorption.

The adsorption of anions onto metal surfaces is important in many applications including effective (electro)catalyst design, metal surface modification, and contaminant removal in wastewater treatment. In electrocatalysis, anions can be both reactive intermediates or site-blocking spectators, where their adsorption strength therefore dictates the rate of reaction. In this work, we have measured the adsorption energy of a series of carboxylic acids on a Pt (111) single-crystal electrode surface from aqueous solution. We find that the adsorption strength of the carboxylate anion is linearly correlated with its acid-dissociation constant (pKa) and therefore the heterolytic O-H bond dissociation strength in solution. Using density functional theory modeling, we split the anion adsorption energy into a sum of the adsorption energy and electron affinity of a neutral (carboxyl) radical. Surprisingly, the adsorption energy of the carboxyl radicals are similar and therefore the large difference in electron affinity is what dictates anion adsorption strength; the greater the cost in energy to remove the electron from the anion upon adsorption, the weaker its binding. Therefore, at least within a class of anions with similar structure and surface binding atoms, both electron affinity and acidity are predictive descriptors of adsorption strength.

Numerical simulation of resistivity and saturation estimation of pore-type gas hydrate reservoirs in the permafrost region of the Qilian Mountains

Abstract The pore-type hydrate reservoirs in the permafrost region of the Qilian Mountains (PRQM) have complex characteristics, including low porosity, low permeability, high shale content, and conductive minerals. Currently, the research on the electrical properties of these reservoirs still needs to be sufficiently in depth, and there are limitations in well-logging evaluation methods. To fill in this gap, a conductivity model of pore-type gas hydrate reservoirs (GHRs) is established based on the pore-combination modeling theory to investigate the influencing factors of the resistivity characteristics of GHRs through numerical simulations. The comparison between the laboratory-measured resistivity of different hydrate saturations and the results of the calculated model shows good agreement, indicating the accuracy of the conductivity model in describing the electrical characteristics of GHRs in the PRQM. Compared to conductive minerals, the numerical simulation results indicate that the high shale content is the main reason for the decrease in resistivity of pore-type GHRs in the study area. The hydrate saturation evaluation of well DK-3 from 386.3 to 393.6 m depth shows that the hydrate saturation ranges from 5.1 to 66.4%, with an average value of 44.0%. The identified hydrate interval using this model is consistent with the actual hydrate interval encountered during the drilling. This study, as an innovation, can help clarify the conductive mechanism of pore-type GHRs in the PRQM and provide more accurate parameters for evaluating gas hydrate resources in the study area.