Model Theory Research Articles

Energy-Efficient Algorithm for Data Path Selection in High-Density Wireless Sensor Networks

Relevance. Increasing the number of sensor devices per unit area consequently reduces the physical distance between the devices in the sensor network. Such networks are usually deployed over a large area and the sensor device that wants to transmit a data packet is located far away from the base station. In such a case, the source device is challenged to choose a transmission path that consumes the least amount of energy resources and satisfies the delivery time requirements. The objective of this study is to develop and validate the effectiveness of an empirical algorithm for selecting a transmission path that reduces the energy consumption of high-density wireless sensor networks. Methods of system analysis, analytical modeling, geometry and probability theories are used. Solution. It is assumed that the sensor network is deployed in a limited area and is a set of devices that are connected to each other informationally and energetically. When building data transmission routes, any sensor devices can be used as repeaters. At the same time, the increase in the number of repeaters leads to an increase in the time of data delivery. Novelty. It is assumed that the sensor network is deployed in a limited area and is a set of devices that are connected to each other informationally and energetically. Any sensor devices may be used as repeaters when constructing data transmission routes.Significance (theoretical). Dependences of power consumption level on various system parameters affecting the processes of functioning of high-density wireless sensor networks have been obtained. Significance (practical). The proposed empirical algorithm for selecting a rational data transmission route in a wireless sensor network allows us to determine, among all alternatives, the route to the coordinator that requires the least power. The effectiveness of the proposed empirical power-saving algorithm is confirmed by simulation modeling.

The Influence of Extraversion Personality, Peer Conformity, and School Climate on Relational Bullying in Boarding School Students

Relational bullying is a form of indirect bullying that often occurs in schools, involving acts of exclusion, neglect, spreading negative rumors, gossip, and social manipulation. This research aims to develop a theoretical model of relational bullying and determine the influence of extraversion personality, peer conformity, and school climate on it in boarding students. This research uses a quantitative approach. The study involved 210 madrasah tsanawiyah students boarding at Makrifatul Ilmi and Al Quraniyah Islamic boarding schools in South Bengkulu Regency. The results showed that theoretical models of influence can influence relational bullying among students. The R square value was 0.68, indicating that personality variables extraversion, peer conformity, and school climate can explain relational bullying by 68%. Extraverted personality had a positive effect on relational bullying, peer conformity had a positive effect, and school climate had a positive effect. This research contributes to the development of a more specific relational bullying theory model in psychology and suggests a holistic approach that includes guidance and counseling for teachers, collaboration between parents and the school, socialization and education for interventions to overcome relational bullying behavior.

Pre-natal and early life lead exposure and childhood inhibitory control: an item response theory approach to improve measurement precision of inhibitory control

BackgroundNeurodevelopmental performance tasks are often separately analyzed, even when they tap into a similar construct. This may yield mixed findings for associations of an exposure-neurobehavioral outcome. We develop an item response theory (IRT) approach to integrate multiple task variables together to improve measurement precision of the underlying construct. We apply this approach to create an integrative measure of childhood inhibitory control, and study impacts of pre/post-natal lead exposure.MethodsUsing data from a prospective cohort based in Mexico (N = 533), we created an inhibitory control scale that integrates accuracy and reaction time information from four inhibitory control tasks (Go/NoGo Letter, Go/NoGo Neutral, Go/NoGo Happy, Delis-Kaplan Executive Function System (D-KEFS) Color-Word Interference Test, Condition 3). Using a generalized partial credit item response theory model, we estimated an inhibitory control index for each participant. We then assessed adjusted associations between umbilical cord blood and 4-year lead and childhood inhibitory control. We developed a resampling approach to incorporate error estimates from the inhibitory control variable to confirm the consistency of the lead-inhibitory control associations. We modeled time-varying associations of lead with each inhibitory control measure separately.ResultsParticipants had a median age of 9 years; 51.4% were males. Umbilical cord blood [-0.06 (95% CI: -0.11, -0.01)] and 4-year lead [-0.07 (95% CI: -0.12, -0.02)] were associated with inhibitory control index at 8–10 years. A resampling approach confirmed that 4-year lead was consistently associated with childhood inhibitory control index. Umbilical cord blood and 4-year lead were each associated with 3 out of 8 measures in separate models.ConclusionThis is the first application of IRT in environmental epidemiology to create a latent variable for inhibitory control that integrates accuracy and reaction time information from multiple, related tasks. This framework can be applied to other correlated neurobehavioral assessments or other phenotype data.

Examining the Role of Family, Media, Peers in Young Caucasian Men’s Understandings of Body Dissatisfaction: A Thematic Analysis Using the Tripartite Influential Model and Social Comparison Theory

This study explores the factors contributing to body dissatisfaction among young Caucasian men. It focuses on family, peers, and media influences, addressing a gap in the literature that rarely integrates men’s experiences. The research draws on the Tripartite Influence Model and Social Comparison Theory, using thematic analysis to examine semi-structured interviews with eight participants aged 20–21. The research considers participants’ sexual orientation and country of origin when analysing the data. The findings show that family, peers, and the media positively and negatively shape body dissatisfaction among participants. Positive familial support can enhance body image, while negative comments from family members and peers exacerbate dissatisfaction. Social media was found to often reinforce unattainable body standards. The research contributes to the limited literature on men’s body dissatisfaction by expanding the application of the Tripartite Influence Model and Social Comparison Theory to this population. The study underscores the need for greater societal awareness and a more inclusive approach to body image research that considers diverse ethnic backgrounds and sexual orientations. We argue that more attention needs to be paid to men’s body dissatisfaction, as men are often excluded from these discussions. This study provides valuable insights into the dynamics of male body image, offering a foundation for future research and societal discourse on this often-overlooked issue.

Chitosan grafted with gallic acid and cerium dioxide hybrid nanocomposites as environmentally friendly corrosion inhibitors for mild steel: An experimental and computational study

Chitosan grafted with gallic acid (CS-GA), along with CS-GA doped with CeO2 nanoparticles (CS-GA-CeO2) were synthesized as novel environmentally friendly mild steel corrosion inhibitors. The formation of these derivatives was confirmed by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), hydrogen nuclear magnetic resonance spectroscopy (1H NMR), and thermal analysis (TGA). Based on potentiodynamic polarization curves (PDP) measurements, the inhibitors acted primarily as hybrid inhibitors, while following the Langmuir adsorption theory model. Scanning electron microscopy (SEM), X-ray photoelectron spectroscopy(XPS) and 3D surface profiles, confirmed that CS-GA-CeO2 adsorbed on the mild steel forming a protective layer thus preventing the invasion of corrosive media. The corrosion protection mechanism of chitosan derivatives was investigated by molecular dynamics simulations. Electrochemical measurements were used to investigate the corrosion inhibition by CS-GA and CS-GA-CeO2 on mild steel in a 3.5 % NaCl solution. At room temperature, the highest inhibition efficiency (93.58 %) was achieved at 200 ppm CS-GA-CeO2. Modified chitosan nanocomposites were confirmed as promising corrosion inhibitors.

Model theory and agnostic online learning via excellent sets

We use algorithmic methods from online learning to explore some important objects at the intersection of model theory and combinatorics, and find natural ways that algorithmic methods can detect and explain (and improve our understanding of) stable structure in the sense of model theory. The main theorem deals with existence of ϵ \epsilon -excellent sets (which are key to the Stable Regularity Lemma, a theorem characterizing the appearance of irregular pairs in Szemerédi’s celebrated Regularity Lemma). We prove that ϵ \epsilon -excellent sets exist for any ϵ > 1 2 \epsilon > \frac {1}{2} in k k -edge stable graphs in the sense of model theory (equivalently, Littlestone classes); earlier proofs had given this only for ϵ > 1 / 2 2 k \epsilon > 1/{2^{2^k}} or so. We give two proofs: the first uses regret bounds from online learning, the second uses Boolean closure properties of Littlestone classes and sampling. We also give a version of the dynamic Sauer-Shelah-Perles lemma appropriate to this setting, related to definability of types. We conclude by characterizing stable/Littlestone classes as those supporting a certain abstract notion of majority: the proof shows that the two distinct, natural notions of majority, arising from measure and from dimension, densely often coincide.

The purely iterative conception of set

Abstract According to the iterative conception of set, sets are formed in stages. According to the purely iterative conception of set, sets are formed by iterated application of a set-of operation. The cumulative hierarchy is a mathematical realization of the iterative conception of set. A mathematical realization of the purely iterative conception can be found in Peter Aczel’s type-theoretic model of constructive set theory. I will explain Aczel’s model construction in a way that presupposes no previous familiarity with the theories on which it is based.

Relaxation and fluctuations of a mass- and dipole-conserving stochastic lattice gas

Han [] have recently introduced a classical stochastic lattice gas model which, in addition to particle conservation, also conserves the particles' dipole moment. Because of its intrinsic nonlinearity this model exhibits unusual macroscopic scaling behaviors, different from those of lattice gases that conserve only the number of particles. Here we investigate some basic relaxation and fluctuation properties of this model at large scales and at long times. These properties crucially depend on whether the total number of particles is infinite or finite. We find similarity solutions, describing relaxation of the dipole-conserving gas (DCG) in several standard settings. A major part of our effort is an extension to this model of the macroscopic fluctuation theory (MFT), previously developed for lattice gases where only the number of particles is conserved. We apply the MFT to the calculation of the variance of nonequilibrium fluctuations of the excess number of particles on the positive semi-axis when starting from an (either deterministic, or random) constant density at t=0. Using the MFT, we also identify the equilibrium Boltzmann-Gibbs distribution for the DCG. Finally, based on these results, we determine the probability distribution of, and the most probable density history leading to, a large deviation in the form of a macroscopic void of a given size in an initially uniform DCG at equilibrium. Published by the American Physical Society 2024

Viviparity is associated with larger female size and higher sexual size dimorphism in a reproductively bimodal lizard.

Squamate reptiles are central for studying phenotypic correlates of evolutionary transitions from oviparity to viviparity because these transitions are numerous, with many of them being recent. Several models of life-history theory predict that viviparity is associated with increased female size, and thus more female-biased sexual size dimorphism (SSD). Yet, the corresponding empirical evidence is overall weak and inconsistent. The lizard Zootoca vivipara, which occupies a major part of Northern Eurasia and includes four viviparous and two non-sister oviparous lineages, represents an excellent model for testing these predictions. We analysed how sex-specific body size and SSD is associated with parity mode, using body length data for nearly 14,000 adult individuals from 97 geographically distinct populations, which cover almost the entire species' range and represent all six lineages. Our analyses controlled for lineage identity, climatic seasonality (the strongest predictor of geographic body size variation in previous studies of this species) and several aspects of data heterogeneity. Parity mode, lineage and seasonality are significantly associated with female size and SSD; the first two predictors accounted for 14%-26% of the total variation each, while seasonality explained 5%-7%. Viviparous populations exhibited a larger female size than oviparous populations, with no concomitant differences in male size. The variation of male size was overall low and poorly explained by our predictors. Albeit fully expected from theory, the strong female bias of the body size differences between oviparous and viviparous populations found in Z. vivipara is not evident from available data on three other lizard systems of closely related lineages differing in parity mode. We confront this pattern with the data on female reproductive traits in the considered systems and the frequencies of evolutionary changes of parity mode in the corresponding lizard families and speculate why the life-history correlates of live-bearing in Z. vivipara are distinct. Comparing conspecific populations, our study provides the most direct evidence for the predicted effect of parity mode on adult body size but also demonstrates that the revealed pattern may not be general. This might explain why across squamates, viviparity is only weakly associated with larger size.

Advanced Human Reliability Analysis Approach for Ship Convoy Operations via a Model of IDAC and DBN: A Case from Ice-Covered Waters

The melting of Arctic ice has facilitated the successful navigation of merchant ships through the Arctic route, often requiring icebreakers for assistance. To reduce the risk of accidents between merchant vessels and icebreakers stemming from human errors during operations, this paper introduces an enhanced human reliability assessment approach. This method utilizes the Dynamic Bayesian Network (DBN) model, integrated with the information, decision, and action in crew context (IDAC) framework. First, a qualitative analysis of crew maneuvering behavior in scenarios involving a collision with the preceding vessel during icebreaker assistance is conducted using the IDAC model. Second, the D–S evidence theory and cloud models are integrated to process multi-source subjective data. Finally, the human error probability of crew members is quantified using the DBN. The research results indicate that during convoy operations, the maximum probability that the officer on watch (OOW) chooses an incorrect deceleration strategy is 8.259×10−2 and the collision probability is 4.129×10−3. Furthermore, this study also found that the factors of Team Effectiveness and Knowledge/Abilities during convoy operations have the greatest impact on collision occurrence. This research provides important guidance and recommendations for the safe navigation of merchant ships in the Arctic waters. By reducing human errors and adopting appropriate preventive measures, the risk of collisions between merchant ships and icebreakers can be significantly decreased.

Research on the Food Service Industry in Central Taiwan

This study examined the changes in business models in the food service industry of Taiwan in the postpandemic era. After staying at home for a more prolonged period during the pandemic. More consumers choose to cook at home to save costs, leading to a booming homemade food market. This trend greatly increases the popularity of convenient meal kits, semi-finished products, and do-it-yourself (DIY) meal sets. It not only caters to consumers’ interest in cooking but also provide convenient and quick solutions for food preparation. Food and beverage businesses have successfully expanded their market reach by developing high-quality homemade food products and utilizing social media and e-commerce platforms for sales. The immediacy and wide audience coverage of social media economy have enabled influencers and food bloggers to directly demonstrate the use and effects of meal kits and DIY dining through live streams and short videos. This approach attracts large numbers of followers to purchase these products, thereby quickly enhancing product awareness and sales. Collaborating with social media has become an effective marketing strategy for food and beverage businesses because it increases brand exposure and allows for product adjustments and improvements based on immediate consumer feedback. This study aims to analyze the post-pandemic restaurant industry through the lens of business models. By conducting interviews with restaurant owners across various sectors in central Taiwan, the research will explore how they confronted the challenges during the pandemic and how they have adjusted their business strategies in the aftermath. The objective is to identify future strategies suitable for the Taiwanese culinary market. This study employs business model theory and interview methodology to investigate six companies within Taiwan's restaurant industry. Through comprehensive analysis, the research aims to determine how the restaurant industry should adjust its strategic direction in the post-pandemic era. The interviewed restaurants implemented various adjustments during the postpandemic period, including arranging for industry–academia collaboration, enhancing employee training and incentives, strengthening restaurant recognition and sense of pride among employees, diversifying dish presentation, improving customer service systems, providing customized services, increasing investment in social media, reinforcing supplier relations, and expanding into new distribution channels. The study results indicate that food and beverage businesses can further explore the potential of social media economy, develop more products suitable for online promotion, and continually optimize marketing strategies by leveraging data analysis and market research to meet consumer demands.

Finch-Skea quintessence models in non-conservative theory of gravity

This study is dedicated to presenting a new solution of the field equations in the Rastall theory with a quintessence field defined by the parameter ωq as −1<ωq<−13 by considering the isotropic matter content inside the sphere. The Finch-Skea ansatz (FS) is used in a static and spherically symmetric geometry to obtain the feasible relativistic solution. The results obtained in the physical evaluation are analyzed analytically and graphically. In the appropriate limit of the Rastall coupling parameter, one can regain the original results in the General Relativity. This complete analysis considers five different compact stars: HerX−1 with mass 0.88M⊙ and radius 7.7 km, VelaX−12 with mass 1.77M⊙ and radius 9.99 km, SAXJ1808−3658(SSI) with mass 1.435M⊙ and radius 7.07 km, 4U1608−52 with mass 1.74M⊙ and radius 9.30 km, 4U1538−52 with mass 0.87M⊙ and radius 7.86 km and PSRJ1416−2230 with mass 1.97M⊙ and radius 10.30 km. The physical validity of the obtained solution is verified by computing the necessary physical parameters like energy density and pressure, quintessence density, energy conditions, sound speed via the Herrera cracking concept, hydrostatic equilibrium of forces, mass function, compactness, Buchdahl limit, and surface redshift and analyze their behavior graphically. To investigate the demeanor of these parameters more closely, we computed the numerical values and manifested them in tabular form. We conclude that our presented mathematical model of compact stars in the Finch-Skea geometry with quintessence field fulfills all the requirements for a physically viable solution.

A comprehensive analysis of charged pulsars and cracking condition

The main aim of this manuscript is to analyze the viability and stability of pulsars filled with charged anisotropic matter configuration in extended symmetric teleparallel theory. A particular model of this gravitational theory is considered to reduce the complexity of the system and formulate the explicit field equations which govern the interaction between matter and geometry. The configuration of static spherical symmetric structures is examined through the non-singular viable solutions. The undetermined constants in the metric coefficients are determined by the Darmois junction conditions. Further, we explore different physical characteristics in the interior of charged pulsars to check their viability. The equilibrium state of the charged stellar objects is discussed using the Tolman–Oppenheimer–Volkoff equation and the stability is examined by the causality condition, Herrera cracking approach and adiabatic index, respectively. Our findings indicate that the proposed charged stars in this modified gravity are physically viable and stable.

APAKAH PROGRAM “JAMULA” BERDAMPAK TERHADAP PERUBAHAN SOSIAL EKONOMI MASYARAKAT KABUPATEN LAMONGAN? DITINJAU DARI TEORI MERILEE GRINDLE

The purpose of this study is to analyze the influence of policy content and implementation context in the Merilee Grindle theory of the Jamula policy on the Sukodadi-Sumberwudi highway of Pucangro Village on the impact and changes and acceptance of the people of Lamongan district. This research was conducted quantitatively with an exploratory approach. The sample of this study amounted to 100 people from the people of Lamongan Regency and the sample was obtained from a nonprobability sampling technique with snowball sampling. The data obtained is then processed using the Structural Equation Model analysis tool based on Partial Least Square (SEM-PLS). The hypothesis of this study is that the policy content variable and the implementation context variable of the Jamula policy on the Sukodadi-Sumberwudi highway of Pucangro Village have an influence on impact variables as well as change and acceptance variables. The test results show that policy content has an influence on impact, policy content has an influence on change and acceptance, and the context of implementation has an influence on change and acceptance. There is one hypothesis that is not empirically proven, namely that the context of implementation has no effect on impact. The conclusions of this study are: (1) the three hypotheses based on the theory of the merilee grindle implementation model are acceptable or empirically provable; (2) one hypothesis is rejected is the influence of the implementation context on the impact and the author assumes that the implementation context carried out by the Lamongan Regency government is ineffective, so that the community does not feel the positive impact of the Jamula policy on the Sukodadi-Sumberwudi highway in Pucangro Village. The Jamula program provides positive benefits to the community, so the government must be responsive and timely in repairing roads to increase community satisfaction.

Angle-dependent Hall resistivity and longitudinal resistivity of type-II superconductor

We use time-dependent Ginzburg–Landau theory in a three-dimensional model, including thermal noise, to analyze angle-dependent Hall resistivity and longitudinal resistivity of type-II superconductor. The Hall resistivity and longitudinal resistivity are calculated as functions of temperature, magnetic field and the angle θ between the magnetic field and the ab-plane in the vortex-liquid regime. Our theoretical calculations within a self-consistent fluctuation approximation for MgB2 and HgBa2 CaCu2O6 materials are in good agreements with the experimental findings for both below and above the critical temperature Tc. We observe that when the field angle decreases, the transition temperature increases and the magnitude of longitudinal resistivity decreases, which is qualitatively comparable to decrease of the perpendicular field component. However, when the magnetic field direction approaches the layer surface, it shows a clear different effect from that of a perpendicular field with the same normal component.

Machine learning and DFT dual-guidance of carbon dots implanted SrTiO3 hollow nanosphere for efficient all-pH-value photocatalysis

The photo-Fenton-like reaction holds significant promise for treating low-concentration antibiotic wastewater, yet its progress is hindered by the weak adsorption and activation ability of peroxydisulfate (PDS) and limited pH application range. This work employs density functional theory and machine learning models in tandem to craft optimal photocatalysts for tetracycline (TC) degradation across all pH ranges. Our investigation reveals that carbon dots (CDs) modified SrTiO3 hollow nanospheres exhibit robust PDS adsorption and activation capabilities, facilitating electron transfer from the photocatalyst to SO4•-. Additionally, the abundant functional groups on CDs confer a protective effect on SrTiO3, shielding it from corrosion by strong acids and bases. Consequently, CDs-SrTiO3 demonstrates excellent photocatalytic performance across the entire pH spectrum, particularly in alkaline and extremely acidic conditions. Furthermore, CDs deposition enhances the solar utilization, specific surface active site amount, and hydrophilicity of SrTiO3. Theoretical calculations and experimental characterizations elucidate the degradation mechanism and pathways of TC, while machine learning models optimize the experimental parameters. This work provides valuable insights into the rational design and adept preparation of high-quality photocatalysts suitable for a wide pH range towards wastewater treatment.

Experimental and Theoretical Analysis on the Thermomechanical Properties of Functionally Graded Graphene Nanoplatelet Reinforced Cement Composites

Graphene reinforced cement composites (GRCCs) have attracted great attention due to their excellent mechanical and physical properties. Instead of uniform distribution, the functionally graded distribution of graphene fillers can effectively utilize the mechanical and physical properties of the reinforcements while reducing cost. This paper is the first attempt to combine experimental analysis and theoretical modelling to investigate the thermomechanical properties of functionally graded graphene nanoplatelet (GNP) reinforced cement composites (FG-GNPRCCs). Samples with uniform (profile H) and functionally graded (profiles X, O and A) distribution of GNPs were prepared and tested. Among all the FG distribution patterns as involved, profile X exhibited the most pronounced enhancement. Compared to the uniform distribution at room temperature, the loss factor and storage modulus of profile X increased by 19.3% and 19.5%, respectively. Based on the effective medium theory (EMT) and Mori-Tanaka (MT) model, a parallel triple-inclusion model was developed to predict the thermal conductivity of GNPRCCs. The effects of coated GNP, agglomeration and the attributes of pores (i.e., size, shape and porosity) on the thermomechanical properties of the composites were considered. Dynamic mechanical analysis revealed that profile X had the best energy dissipation and the extent of inelastic deformation within the temperature range from -50 °C to 70 °C. In contrast, profile A is beneficial for scenarios that desire a gradual transition and controlled stress along a certain direction.

Operational reliability assessment of complex mechanical systems with multiple failure modes: An adaptive decomposition-synchronous-coordination approach

To effectively perform Complex Mechanical Systems Operational Reliability Assessment (CSORA) with multiple failures, the Adaptive Decomposition-Synchronous-Coordination Approach (ADSCA) is proposed by integrating Decomposition-Synchronous-Coordination strategy, adaptive modeling technology, surrogate model and multi-objective reliability assessment theory. In which, the main problem is decomposed into related sub-problems using a Decomposition-Synchronization-Coordination strategy, with sub-models coordinated to achieve synchronous mapping between multiple variables, thereby enhancing efficiency in large multi-subsystem problems. The adaptive modeling technique is adopted to construct a series of interrelated sub models based on the surrogate model as the basis function, improving performance. A multi-objective reliability assessment theory is adopted to achieve CSORA under multiple fault modes, where multiple weak links are integrated to comprehensively evaluate the reliability of complex systems. The significance of the ADSCA lies in its ability to manage complexity, enhance scalability, and improve the accuracy and efficiency of reliability assessments in complex mechanical systems. To demonstrate the effectiveness of the proposed approach, two illustrative examples are used. This includes approximation and probability analysis of nonlinear functions that exhibit multiple responses, as well as reliability analysis of temperature in civil aircraft braking system. The study can provide theoretical reference for the reliability evaluation of multi-failure operation in complex mechanical systems.

Unraveling Abnormal Thermal Quenching of Sub‐Gap Emission in β‐Ga2O3

AbstractIn this work, the optical transition of self‐trapped excitons (STEs) and the emergent green emission in β‐Ga2O3 samples with/without Sn impurities at various doping levels have been investigated via temperature‐ and power‐dependent photoluminescence. The ultraviolet (UV) emissions ≈ 3.40 eV unanimously exhibit an excitonic nature related to STEs and typical negative thermal quenching (NTQ) characters. The NTQ activation energy decreases from 103.56 to 42.37 meV with the increased electron concentration from 2.1 × 1016 to 6.7 × 1018 cm−3, indicative of the reduced energy barrier that electrons should overcome to form stable STEs due to the lift‐up of Fermi level. In comparison, the green emissions ≈ 2.35 eV with two quenching channels are observed only in samples with Sn impurities at cryogenic temperatures. One channel is the nsnp‐ns2 transition of Sn2+, the other is donor‐acceptor pair recombination via (2VGa‐Sni)2− complex, which is energetically favorable as evidenced by density functional theory calculations. The semi‐classical quantum theory models fitting proves the transition from green to UV emissions with elevated temperature. The enhanced STEs emission with distinguished NTQ effect strengthens evidence that the stable polarons inherently limit the transport of holes in Ga2O3, and also support the potential of Ga2O3 materials for the development of UV optoelectronics.

AlN/GaN Superlattice band structure calculation Using Empirical Tight Binding Model

AlN/GaN superlattices are studied using the empirical tight-binding method (ETBM) with sp3 approximation. The model includes first-nearest-neighbor orbital interactions and accounts for the strain effect by modifying the ETBM parameters based on variations in bond lengths and angles. According to the authors knowledge, this study marks the first application of ETBM to determine the full band structure of AlN/GaN superlattices. On average, the ETBM band gaps resulting from this work are 7.48% closer to the experimental data in comparison with Kronig-Penney outputs. In addition to the high accuracy of the model, the presented model is easier to implement compared to the density functional theory model.