Model Theory Research Articles

Modeling of pulse and relaxation of high-rate Li/CFx-SVO batteries in implantable medical devices

We present a Hybrid Multiphase Porous Electrode Theory (Hybrid-MPET) model that accurately predicts the performance of Medtronic’s implantable medical device battery lithium/carbon monofluoride (CFx) - silver vanadium oxide (SVO) under both low-rate background monitoring and high-rate pulsing currents. The distinct properties of multiple active materials are reflected by parameterizing their thermodynamics, kinetics, and mass transport properties separately. Diffusion limitations of Li+ in SVO are used to explain cell voltage transient behavior during pulse and post-pulse relaxation. We also introduce change in cathode electronic conductivity, Li metal anode surface morphology, and film resistance buildup to capture evolution of cell internal resistance throughout multi-year electrical tests. We share our insights on how the Li+ redistribution process between active materials can restore pulse capability of the hybrid electrode, allow CFx to indirectly contribute to capacity release during pulsing, and affect the operation protocols and design principles of batteries with other hybrid electrodes. We also discuss additional complexities in porous electrode model parameterization and electrochemical characterization techniques due to parallel reactions and solid diffusion pathways across active materials. We hope our models can complement future experimental research and accelerate development of multi-active material electrodes with targeted performance.

Compressive failure analysis of composite honeycomb sandwich panels with impact damage and stepped-scarf repairs

Composite honeycomb sandwich panels (CHSPs) have been widely used in the aerospace industry owing to their lightweight and superior mechanical properties. However, these CHSPs are susceptible to impact damage, leading to a significant reduction in compressive strength and potentially jeopardize aircraft safety. It is crucial to investigate repair methods for CHSPs with impact damage. This paper aims to evaluate the repair performance of CHSPs with impact damage through an analysis of their compressive failure behaviors. To accomplish this, both experimental tests and advanced numerical models are employed. The numerical models for the intact, damaged and stepped-scarf repaired CHSPs are established using the progressive failure analysis model, cohesive zone model and sandwich plate theory. A good agreement is observed between the experimental results and numerical predictions of compressive failure behaviors. Moreover, the validated numerical models are successfully utilized for determining optimum repair parameters by parametric analysis of the repaired CHSPs. The establishment of these numerical models offers an accurate and cost-effective evaluation of repair performance for CHSPs with impact damage, highlighting the novelty and main contribution of this paper.

Study of Light Pollution Risk Evaluation Model

The invention and widespread use of artificial light are important progress in human history, but the light pollution formed by its excessive or poor use is a serious danger to biodiversity and ecosystems, etc. Behind the bright lights of the busy city, it is also a metaphor for the bright starry sky far away from us. Though using the theory and methods of risk identification and evaluation hierarchical model, and unconfirmed measurement model, the index system and the measuring method on the risk level of light pollution are established, the Light pollution risk evaluation model is formed, and they are applied to interpret their results for the four diverse types of locations. The order of the ratings is urban communities, suburban communities, rural communities, and protected land according to high to low. They meet the results from the literature, which confirms the reasonableness of the risk level measures developed. Our work provides a certain reference for the research and treatment of light pollution.

An enhanced strain gradient model for temperature-dependent sound transmission loss in double-walled functionally graded microplates

With the growing use of functionally graded (FG) microplates in structural acoustic metamaterials for aerospace and automotive applications, accurate modeling of sound transmission loss is critical for effective vibration and noise control engineering. In this study, a theoretical model is formulated based on the first-order shear deformation theory (FSDT) to estimate sound transmission loss (STL) through air-filled rectangular double-walled FG microplates with simply supported boundary conditions. The microplates are subjected to a nonlinear thermal environment, and the modified strain gradient theory (MSGT) is employed, incorporating three material length scale parameters to account for the size effect. The material properties are temperature-dependent and vary across the thickness following a power-law distribution. Size-dependent coupled vibroacoustic equations are derived utilizing the sound velocity potential, normal velocity continuity conditions, and Hamilton's principle, and are subsequently solved using the Galerkin method. Comparative analysis is performed by contrasting the results obtained from the MSGT model with those from the modified couple stress theory (MCST) and classical continuum theory (CCT) models, allowing for the assessment of the accuracy and precision of the proposed solution. Additionally, the influence of various parameters, such as gradient index, length scale parameters, temperature variation, incident angles, and acoustic cavity depth, on the STL is investigated. Key findings demonstrate that in the stiffness-controlled region, length scale parameters significantly enhance STL, while power-law index and temperature variation reduce it.

Effect of biaxial tensile strain on the thermoelectric properties of monolayer ZrTiCO2

Using ab-initio calculation principle calculations, we investigate the effect of biaxial tensile strain on the stability and electronic properties of the two-dimensional double transition metal MXenes ZrTiCO2. The monolayer ZrTiCO2 has stability and semiconducting properties under different strain conditions. The results of thermoelectric properties under other strain conditions calculated by Boltzmann transport theory and Slack model show that biaxial tensile strain can improve the electrical transport properties of monolayer ZrTiCO2 materials and lead to the decrease of lattice thermal conductivity. The thermoelectric efficiency of a material can be evaluated using the figure of merit ZT. The n-type ZrTiCO2 has a maximum ZT value of 1.49 at 900 K without adding biaxial strain and reaches a ZT value of 2.86 with 2% biaxial strain. The monolayer ZrTiCO2 material has the potential to become a thermoelectric material, and its thermoelectric properties can be improved by biaxial tensile strain.

Psychometric Assessment of an Item Bank for Adaptive Testing on Patient-Reported Experience of Care Environment for Severe Mental Illness: Validation Study.

The care environment significantly influences the experiences of patients with severe mental illness and the quality of their care. While a welcoming and stimulating environment enhances patient satisfaction and health outcomes, psychiatric facilities often prioritize staff workflow over patient needs. Addressing these challenges is crucial to improving patient experiences and outcomes in mental health care. This study is part of the Patient-Reported Experience Measure for Improving Quality of Care in Mental Health (PREMIUM) project and aims to establish an item bank (PREMIUM-CE) and to develop computerized adaptive tests (CATs) to measure the experience of the care environment of adult patients with schizophrenia, bipolar disorder, or major depressive disorder. We performed psychometric analyses including assessments of item response theory (IRT) model assumptions, IRT model fit, differential item functioning (DIF), item bank validity, and CAT simulations. In this multicenter cross-sectional study, 498 patients were recruited from outpatient and inpatient settings. The final PREMIUM-CE 13-item bank was sufficiently unidimensional (root mean square error of approximation=0.082, 95% CI 0.067-0.097; comparative fit index=0.974; Tucker-Lewis index=0.968) and showed an adequate fit to the IRT model (infit mean square statistic ranging between 0.7 and 1.0). DIF analysis revealed no item biases according to gender, health care settings, diagnosis, or mode of study participation. PREMIUM-CE scores correlated strongly with satisfaction measures (r=0.69-0.78; P<.001) and weakly with quality-of-life measures (r=0.11-0.21; P<.001). CAT simulations showed a strong correlation (r=0.98) between CAT scores and those of the full item bank, and around 79.5% (396/498) of the participants obtained a reliable score with the administration of an average of 7 items. The PREMIUM-CE item bank and its CAT version have shown excellent psychometric properties, making them reliable measures for evaluating the patient experience of the care environment among adults with severe mental illness in both outpatient and inpatient settings. These measures are a valuable addition to the existing landscape of patient experience assessment, capturing what truly matters to patients and enhancing the understanding of their care experiences. ClinicalTrials.gov NCT02491866; https://clinicaltrials.gov/study/NCT02491866.

Investigating User Experience of VR Art Exhibitions: The Impact of Immersion, Satisfaction, and Expectation Confirmation

As an innovative form in the digital age, VR art exhibitions have attracted increasing attention. This study aims to explore the key factors that influence visitors’ continuance intention to VR art exhibitions using the expectation confirmation model and experience economy theory and to explore ways to enhance visitor immersion in virtual environments. We conducted a quantitative study of 235 art professionals and enthusiasts, conducted using the partial least squares structural equation modeling (PLS-SEM), to examine the complex relationship between confirmation (CON), Perceived Usefulness (PU), Aesthetic Experiences (AE), Escapist Experiences (EE), Satisfaction (SAT), and Continuance Intention (CI). The results show that confirmation plays a key role in shaping PU, AE, and EE, which in turn positively affect visitors’ SAT. Among these factors, AE positively impacts PU, but EE have no impact. A comprehensive theoretical model was then constructed based on the findings. This research provides empirical support for designing and improving VR art exhibitions. It also sheds light on the application of expectation confirmation theory and experience economy theory in the art field to improve user experience and provides theoretical guidance for the sustainable development of virtual digital art environment.

The Role of Lamprey Sex Ratios in Ecosystem Dynamics: An Analysis Using Lotka-Volterra Models

With global ecological changes, studying the sex ratio of lampreys in ecosystems and their impact on the food chain and ecological stability has become a key topic in ecology and environmental science. Lampreys are found mainly in the North Pacific region and are considered to be parasites that have a significant impact on the ecosystem. The sex ratio of lampreys is not as 1:1 as in most species, depending on how quickly they grow during the larval stage. In response to this, this study started with the living habits of lampreys and studied the impact of different years in different watersheds on the sex ratio of lampreys, as well as the relationship between water temperature and catch quantity. Subsequently, the Lotka-Volterra model theory was applied to prove that the sex ratio of lampreys has a greater impact on ecosystems in simpler food chains, but a smaller impact in more complex food chains. This study successfully revealed when the population of lamps can alter its sex ratio, lampreys have a certain impact on the quantity and structure of species in ecosystems.

ANALISA KESUKSESAN OTA (ONLINE TRAVEL AGENT) TIKET.COM MENGGUNAKAN MODEL DELONE AND MCLEAN (Studi pada Pembelian Tiket Konser K-Pop di Indonesia)

The growth of Korean Wave in Indonesia has been very significant since the beginning of the pandemic in 2020 and the interest in K-Pop music is one proof of the phenomenon of Korean Wave in Indonesia. The huge interest in K-Pop music has attracted the attention of promoters to hold K-Pop music concerts in Indonesia. One of the elements in holding a music concert is ticket sales, and promoters will choose to prioritize online ticket sales to facilitate sales. One of the online ticket sales platforms for K-pop music concerts in Indonesia is tiket.com. As an online ticket sales platform, tiket.com must consider the quality of their system. This study aims to determine the factors that influence the success of the tiket.com platform using the DeLone and McLean Model theory (2003). The research method used is quantitative. The sampling technique used is nonprobability sampling technique with a sample of 100 respondents from tiket.com platform users who have transacted K-pop concert tickets. Data analysis was carried out using the PLS-SEM approach with the SmartPLS tool. The results of this study indicate that there is a significant effect on system quality, information quality and service quality on user satisfaction and a significant effect of user satisfaction on net benefits.

Investigating The Impact of Digital Technology on Adolescent Identity Formation on Selected Students in SAIS: A Psychological Approach

Teenagers are today living in a hybrid world that connects digital spaces to offline contexts; we are amid a global shift where digital "screens" are no longer only entertainment devices yet a major distraction. Adolescence is a period of self-actualization, self- integration, and, in the current era, consistent social media performance. Conflicts in the identity vs. role confusion stage of Erik Erikson and James Marcia theory of identity statues model are addressed throughout this research. A survey, sent to Sharjah American International School high school students, explores the aftermath of the online metaverse impact on their identity development. The aim of the present study was to examine the interrelationships between adolescent media activity and identity development through studying behavioral outcomes to psychological analyze results. Participating in the study were 19 adolescents ages 13 to 19 (mean age 17). The results showed identity was however negatively associated with time spent using the network on social media and communicating. On the other hand, identity style was also positively associated with adaptive media- related cognitions, such as benefiting from the online metaverse to absorb new knowledge constantly. The results are discussed regarding practical implications and recommendations for enhancing parenting styles and guidance of adolescents.

Choosing between commercially pure titanium and Ti-6Al-4V gyroid structures for orthopedic applications: An analysis through Timoshenko beam theory, the Gibson-Ashby model and experimental methods

For decades, research has focused on using gyroid lattice structures to prevent stress-induced osteopenia and improve osseointegration by promoting cell adhesion and transition, particularly in cases where implant removal is not desired after complete healing. Despite these advantages, in-depth research is still needed for innovative biomedical implants to reach optimum functionality. Although commercially pure titanium (Cp-Ti) and Ti6Al4V are both popular materials for standalone bone implants, they are not likely paired within the same application due to mechanical property differences. This study proposes a case-specific workflow to support orthopedic implant design considerations, by analytically and experimentally investigating the mechanical response of additively manufactured lattice gyroid structures in both Cp-Ti and Ti6Al4V with different porosity rates. The experimental results of both materials indicate a significant decrease in the elastic modulus against two employed analytical methods, Gibson-Ashby model and Timoshenko beam theory. This is linked to inherent manufacturing-induced stress concentrations on the physical gyroids. The experimental outcome presents itself significantly closer to the predictions of Timoshenko beam theory compared to Gibson Ashby method. Both gyroid titanium structures are loyal to Timoshenko theory, displaying a combination of multi deformation behaviors instead of one-way deformation. The deformation response of Ti6Al4V showed a 45⁰ shear band while Cp-Ti exhibited smoother deformation during compression. Higher porosity rates led to an increase in ductility due to extended horizontal plateau regions in both Cp-Ti and Ti6Al4V lattice structures. The results provide valuable comparative insight and considerations on the material choice for gyroid lattice structures within bone implants.

Exploring the dual routes in influencing sales and adoption in augmented reality retailing: a mixed approach of SEM and FsQCA

Exploring the dual routes in influencing sales and adoption in augmented reality retailing: a mixed approach of SEM and FsQCA

Elementary properties of free lattices

Abstract We start a systematic analysis of the first-order model theory of free lattices. Firstly, we prove that the free lattices of finite rank are not positively indistinguishable, as there is a positive ∃ ∀ {\exists\forall} -sentence true in 𝐅 3 {\mathbf{F}_{3}} and false in 𝐅 4 {\mathbf{F}_{4}} . Secondly, we show that every model of Th ⁢ ( 𝐅 n ) {\mathrm{Th}(\mathbf{F}_{n})} admits a canonical homomorphism into the profinite-bounded completion 𝐇 n {\mathbf{H}_{n}} of 𝐅 n {\mathbf{F}_{n}} . Thirdly, we show that 𝐇 n {\mathbf{H}_{n}} is isomorphic to the Dedekind–MacNeille completion of 𝐅 n {\mathbf{F}_{n}} , and that 𝐇 n {\mathbf{H}_{n}} is not positively elementarily equivalent to 𝐅 n {\mathbf{F}_{n}} , as there is a positive ∀ ∃ {\forall\exists} -sentence true in 𝐇 n {\mathbf{H}_{n}} and false in 𝐅 n {\mathbf{F}_{n}} . Finally, we show that DM ⁢ ( 𝐅 n ) {\mathrm{DM}(\mathbf{F}_{n})} is a retract of Id ⁢ ( 𝐅 n ) {\mathrm{Id}(\mathbf{F}_{n})} and that for any lattice 𝐊 {\mathbf{K}} which satisfies Whitman’s condition ( W ) {\mathrm{(W)}} and which is generated by join prime elements, the three lattices 𝐊 {\mathbf{K}} , DM ⁢ ( 𝐊 ) {\mathrm{DM}(\mathbf{K})} , and Id ⁢ ( 𝐊 ) {\mathrm{Id}(\mathbf{K})} all share the same positive universal first-order theory.

FlexibleSUSY extended to automatically compute physical quantities in any beyond the standard model theory: Charged lepton flavor violation processes, Higgs decays, and user-defined observables

FlexibleSUSY is a framework for the automated computation of physical quantities (observables) in models beyond the Standard Model (BSM). This paper describes an extension of FlexibleSUSY which allows to define and add new observables that can be enabled and computed in applicable user-defined BSM models. The extension has already been used to include Charged Lepton Flavor Violation (CLFV) observables, but further observables can now be added straightforwardly. The paper is split into two parts. The first part is non-technical and describes from the user's perspective how to enable the calculation of predefined observables, in particular CLFV observables. The second part of the paper explains how to define new observables such that their automatic computation in any applicable BSM model becomes possible. A key ingredient is the new NPointFunctions extension which allows to use tree-level and loop calculations in the model-independent setup of observables. Three examples of increasing complexity are fully worked out. This illustrates the features and provides code snippets that may be used as a starting point for implementation of further observables. Program summaryProgram title:NPointFunctionsCPC Library link to program files:https://doi.org/10.17632/kf7m8gn8vp.2Developer's repository link:https://github.com/FlexibleSUSY/FlexibleSUSYLicensing provisions: GPLv3Programming language:C++, Wolfram Language, Fortran, Bourne shellJournal reference of previous version:: Comput. Phys. Commun. 230 (2018) 145–217; PoS CompTools2021 (2022) 036Does the new version supersede the previous version?: YesReasons for the new version: Program extension including new observables and file structuresNature of problem: Determining observables for an arbitrary extension of the Standard Model supported by FlexibleSUSY, input by the user.Solution method: Generation of the code from automated algebraic manipulations. Automatic filling and compiling of predefined template files.Additional comments including restrictions and unusual features: Vertices with a direct product of Lorentz and color structures are supported. Settings of the advanced NPointFunctions mode rely on explicit specification of topologies.

Development and application of the Meal and Snack Assessment (MESA) quality scale for children and adolescents using item response theory

BackgroundMeals differ in terms of food items and nutritional quality. The aim of the present study was to propose a scale to measure the meals quality of schoolchildren according to food processing degree, perform a preliminary evaluation of the scale's validity and reliability and apply the scale to a representative sample of schoolchildren in a city in southern Brazil.MethodsA methodological study based on the generalized graded unfolding model (GGUM) of item response theory (IRT) with analysis of secondary data was carried out in 6,399 schoolchildren of 6-15y-old attending 2nd to 5th grades of public elementary schools in Florianópolis, Brazil, in 2013–2015 who answered the validated Food Intake and Physical Activities of Schoolchildren (WebCAAFE) questionnaire. Meal quality was the latent trait. The steps for the development of the scale included: latent trait definition; item generation; dimensionality analysis; estimation of item parameters; scale levels definition; assessment of validity and reliability; and assessment of the meal quality of a subsample of schoolchildren aged 7 to 12 years (n = 6,372).ResultsEleven out of eighteen items had adequate parameters, without differential item functioning for sex or age. Meal quality was categorized into three levels: healthy, mixed, and unhealthy. Higher scores indicate a greater prevalence of ultra-processed foods in daily meals. Most schoolchildren had mixed (40.6%) and unhealthy (41%) meal patterns.ConclusionsIRT analysis allowed the development of the scale, which measures the quality of meals and snacks based on the degree of food processing. At all snack times, there was a higher frequency of ultra-processed foods consumption, therefore foods consumed as snacks are a potential focus for nutritional interventions.

One-loop matching of the type-III seesaw model onto the Standard Model Effective Field Theory

In previous works [1, 2], we have performed the one-loop matching of both type-I and type-II seesaw models for neutrino masses onto the Standard Model Effective Field Theories (SMEFT). In the present paper, by matching the type-III seesaw model onto the SMEFT at the one-loop level, we complete this series of studies on the construction of low-energy effective field theories (EFTs) for the canonical seesaw models. After integrating out the heavy fermionic triplets in the type-III seesaw model via both functional and diagrammatic approaches, we find 33 dimension-six (dim-6) operators in the Warsaw basis and their Wilson coefficients, while the number of dim-6 operators is 31 (or 41) for the EFT of type-I (or type-II) seesaw model. Furthermore, we calculate the branching ratios of radiative decays of charged leptons in the EFT. Then, the relationship between the beta function of the quartic Higgs coupling λ in the full theory and that of λEFT in the EFT is clarified. Finally, we briefly discuss the phenomenological implications of three types of seesaw EFTs and propose working observables that are sensitive to the four-fermion operators, which could be used to distinguish among different seesaw models in collider experiments.

Effects of doping with selected rare-earth elements (Eu3+, Dy3+, Eu3+/Dy3+) on the structural characteristics as well as electrical and luminescent properties of K0.5Na0.5NbO3

The effects of adding Eu3+, Dy3+, and Eu3+/Dy3+ rare-earth elements on the microstructural, optical and electrical properties of lead-free piezoelectric materials based on K0.5Na0.5NbO3 (KNN) were investigated. A series of fine powders were synthesized via a modified Pechini route utilizing citric acid. Relatively large amounts of rare-earth elements were successfully incorporated into the crystal lattice of KNN. A combination of X-ray diffraction, X-ray absorption spectroscopy, energy-dispersive X-ray and scanning electron microscopy were used to characterize the structure and chemical composition of the powders and sinters. XRD patterns indicated the formation of a single-phase orthorhombic structure in the co-doped sinter. X-ray absorption spectroscopy revealed the nominal 3+ valence states of Eu and Dy in KNN ceramic sinters. The Mott model and group symmetry theory were used to discuss the characteristics of Raman spectra obtained for the EuDy:KNN ceramics. The ceramics exhibited good dielectric permittivity (ε≃1300) and low dielectric loss (tan δ=0.03) in the temperature range of 170–240°C. The electrical properties of the ceramics showed that the basic mechanism of conduction and relaxation was thermal activation, and that small polaron hopping was responsible for charge carrying. The Eu3+ and Dy3+ ions displayed characteristic red and orange emissions in sinters when excited with light in the wide ultraviolet spectra range (380–420 nm).

Analisis Penerimaan Aplikasi Kubuku oleh Pengguna di UPT Perpustakaan Universitas Andalas: Studi Deskriptif dengan Model Technology Acceptance Model (TAM)

One form of digital library owned by the Andalas University Library UPT is the Kubuku application, however the use of the Kubuku application in this agency is not optimal. This research aims to analyze the acceptance of the Kubuku application by users at the Andalas University Library UPT. The type of research used is a quantitative approach with descriptive methods. The data collection technique was carried out by distributing questionnaires to the respondents. The total population in this study was 437 people. Samples were taken from 81 users using the Slovin formula with a precision of 10%. The analysis was carried out using the Technological Acceptance Model (TAM) theory which consists of 4 indicators. From each indicator, it was found that users had a perception of the usefulness of the application with a percentage of 74.6% in the good category. Users have a perception of ease of use of the application with a percentage of 84% in the very good category. Users have a good interest in using the Kubuku application with a percentage of 72.6%. And the actual use of the Kubuku application is also categorized as good with a percentage of 64%. Based on the overall results of the research, it can be concluded that there is acceptance of the Kubuku application by users at the Andalas University Library UPT with a percentage of 73.8% which is in the good category.

Succinct ordering and aggregation constraints in algebraic array theories

We discuss two extensions to a recently introduced theory of arrays, which are based on considerations coming from the model theory of power structures. First, we discuss how the ordering relation on the index set can be expressed succinctly by referring to arbitrary Venn regions. Second, we show how to add general aggregators to the calculus. The result is a logic that subsumes four previous fragments discussed in the literature and is distinct from array fold logic, in that it can express summations, while its satisfiability problem remains in non-deterministic polynomial time.

Application of ISAK 35 to the Presentation of Financial Reports of the Manado Diocese of the Catholic Church

This study aims to determine the existing forms of financial reporting and to find out stages, impacts and driving factors of the process of implementing ISAK 35 on the presentation of financial reports of the Manado Diocese of the Catholic Church based on the institutional theory of the form of coercive isomorphism and the Edward III model theory, namely communication, resources, disposition, bureaucratic structure. This study uses the method descriptive qualitative where data collection was carried out by means of interviews and documentation studies. The results show that the policy for implementing financial accounting information systems is not yet fully in accordance with applicable accounting standards. The organization has not fully adhered to the standard of ISAK 35. Financial records are processed using existing financial applications. By the aspect of resources, the attitude of the implementers still shows that the implementers still have minimal/not yet adequate knowledge about the accounting system created and communication between implementing agents is not yet optimal. The indicators in the bureaucratic structure variable in the form of SOPs have been achieved well because in 2019 the Manado Diocese has created a Financial Guideline that must be implemented by every parish, although in practice it is not yet perfect. In its implementation, there are still obstacles from a practical perspective, such as human error, hardware weaknesses, software weaknesses and system weaknesses. Efforts to overcome obstacles include continuing to update applications that have been created based on the latest standards and providing regular training materials that are packaged easily so that the attitude of the application implementing agents themselves can accept the new policy and those responsible for parish finances must be wiser and adhere to diocesan policies to produce financial reports that are transparent, accountable, and trustworthy.