Coefficient Functions Research Articles

Coefficient Functionals of Sakaguchi-Type Starlike Functions Involving Caputo-Type Fractional Derivatives Subordinated to the Three-Leaf Function

A challenging part of studying geometric function theory is figuring out the sharp boundaries for coefficient-related problems that crop up in the Taylor–Maclaurin series of univalent functions. Using Caputo-type fractional derivatives to define the families of Sakaguchi-type starlike functions with respect to symmetric points, this article aims to investigate the first three initial coefficient estimates, the bounds for various problems such as Fekete–Szego inequality, and the Zalcman inequalities, by subordinating to the function of the three leaves domain. Fekete–Szego-type inequalities and initial coefficients for functions of the form H−1 and ζH(ζ) and 12logHζζ connected to the three leaves functions are also discussed.

B spline-based estimating equation for varying-coefficient transformation models with right censored data

This article discusses the estimating equation method for varying coefficient transformation models. The B spline technique is used to approximate the unknown functional coefficients, resulting in a parametric model. The approximated model is then given a set of estimation equations. Under some regular conditions, we demonstrate the large sample properties of the resulting estimates. Some simulation studies and a real data application are also employed to assess the performance of our proposed methodologies.

Homogeneity Pursuit in the Functional-Coefficient Quantile Regression Model for Panel Data with Censored Data

Abstract Homogeneity identification of panel data models has been popular in the literature in recent years. Most of the existing works only focus on the complete data case. This paper considers a functional-coefficient quantile regression model for panel data with homogeneity when its response variables are subject to censoring. In particular, we consider a more general censoring framework, i.e. different types of censoring are allowed to occur in the model simultaneously. For this, a “three-stage” method is proposed, which includes the preliminary estimation of subject-specific function coefficients based on data augmentation, the identification of group structure over subjects by clustering, and post-grouping estimation of function coefficients. Simulation studies considering the left-, right-, and double-censored data, are carried out to verify the finite-sample properties of the proposed method. Simulation results show that our method gives comparable performance to the complete data case. The application to the bank stock data further illustrates the practical advantages of this method.

Research on escape route planning analysis in forest fire scenes based on the improved A* algorithm

The forest fire environment is complex and volatile, posing a serious threat to the lives of firefighters at any time. Aiming at how people choose escape routes when facing these dangers, this paper proposed an escape route planning method based on the improved A* algorithm. Taking the forest fire that occurred in Xintian County, Yongzhou City, Hunan Province on October 17, 2022, as the research object, this study collected data from multi-temporal remote sensing imagery including GF-4, and Sentinel-2 to obtain 11 factors affecting the escape route planning. We used the FAHP-CRITIC combination weighting method to analyze the weights of the escape impact factors. Forest fire scenes were categorized into five classes based on escape risk coefficient from high to low. The heuristic function and weight coefficients of the traditional A* algorithm were reconstructed to obtain the improved A* algorithm. The computing time of both A* algorithm is similar in the same fire scene. But the percentage of the escape route length, located inside the high-risk zones, in the total escape route planned by the improved algorithm decreased by 53.63% than that planned by the traditional A* algorithm. The escape risk coefficient was reduced by 24.22%, and the escape safety was significantly improved. On this basis, the study combined the improved A* algorithm with the dynamic escape window method to search for the nearest safe area to the escapees and compute the corresponding escape routes. The real-time safety of the algorithm was verified using GF-1 remote sensing images obtained 7 and 35 min after the previous fire burning moment. Results revealed that the escape paths planned by the improved A* algorithm remained in a safe state and were able to be updated in real time according to the trend of the fire. This demonstrates the ability of the improved A* algorithm to adapt to real-time changes in forest fire scenes. It can provide multiple reliable escape options for escapees, thus scientifically and effectively reducing human casualties.

K2Ag(Ga/In)Br6 lead-free HDPs: Investigation of the elastic, optoelectronic, optical coating, and thermal characteristics for thermoelectric and solar cells

In this study, an investigation of the structural stability, elastic, optoelectronic, thermoelectric, optical thin-film coating, and thermodynamic properties of K2Ag(Ga/In)Br6 (lead-free halide double perovskites, HDPs) was performed using first-principles calculations. The optimized structural parameters are in good agreement with the available data. Furthermore, Goldsmith's tolerance factor indicates an ideal value for both double perovskites, ensuring the structural stability of the cubic perovskites, and the elasticity parameters were analyzed to ensure the mechanical stability of the cubic phase. Direct and reduced band gaps of 0.4524 eV and 1.064 eV with semiconductor behavior are found for K2AgGaBr6 and K2AgInBr6, respectively, through adoption of the modified Becke–Johnson potential scheme. The absorption coefficient, refractive index, and dielectric function, as some of the optical properties, in addition to the optical thin-film properties, are well discussed, and the values suggest that these materials are promising candidates for different devices, such as optoelectronic and photovoltaic energy devices. In terms of the thermodynamics, the HDPs display favorable characteristics across various temperature and pressure ranges. Additionally, we assessed the thermoelectric properties, considering the power factor, Seebeck coefficient, thermal and electronic conductivities, and figure of merit. The current predictions suggest that these lead-free halide double perovskites have strong potential for application in thermoelectricity and photovoltaics.

Anomalous diffusion in external-force-affected deterministic systems.

This study investigates the impact of external forces on the movement of particles, specifically focusing on a type of box piecewise linear map that generates normal diffusion akin to Brownian motion. Through numerical methods, the research delves into the effects of two distinct external forces: linear forces linked to the particle's current position and periodic sinusoidal forces related to time. The results uncover anomalous dynamical behavior characterized by nonlinear growth in the ensemble-averaged mean-squared displacement (EAMSD), aging, and ergodicity breaking. Notably, the diffusion pattern of particles under linear external forces resembles an Ehrenfest double urn model, with its asymptotic EAMSD coinciding with the Langevin equationunder linear potential. Meanwhile, particle movement influenced by periodic sinusoidal forces corresponds to an inhomogeneous Markov chain, with its external force amplitude and diffusion coefficient function exhibiting a "multipeak" fractal structure. The study also provides insights into the formation of this structure through the turnstiles dynamics.

Not all that is β0 is β-function: the DGLAP resummation and the running coupling in NLO JIMWLK

We reanalyze the origin of the large transverse logarithms associated with the QCD one loop β function coefficient in the NLO JIMWLK Hamiltonian. We show that some of these terms are not associated with the running of the QCD coupling constant but rather with the DGLAP evolution. The DGLAP-like resummation of these logarithms is mandatory within the JIMWLK Hamiltonian, as long as the color correlation length in the projectile is larger than that in the target. This regime in fact covers the whole range of rapidities at which JIMWLK evolution is supposed to be applicable. We derive the RG equation that resums these logarithms to all orders in αs in the JIMWLK Hamiltonian. This is a nonlinear equation for the eikonal scattering matrix S(x). We solve this equation, and perform the DGLAP resummation in two simple cases: the dilute limit, where both the projectile and the target are far from saturation, and the saturated regime, where the target correlation length also determines its saturation momentum.

Comparison Theorems for Oscillation of Higher-Order Neutral Delay Differential Equations

In this work, we study the oscillatory features of a class of neutral differential equations with multiple delays. We present novel oscillation conditions for this equation by using a comparison method. We create conditions that exclude the positive solution of the examined equation. Using the feature of symmetry between non-oscillatory solutions (positive and negative), these conditions also exclude negative solutions without adding additional restrictions. In our study, we take into account the even and odd cases of the order of the equation. Furthermore, we study the asymptotic properties in three different cases of functional coefficients. Our results are a fundamental extension and generalization of previous relevant findings, and this fact has been demonstrated through comparisons.

First Principle calculations for structural and optoelectronic properties of MnNi1-xAgxGe alloys: A DFT study

We investigate the optical and electronic characteristics of parental MnNiGe and doped MnNi1-xAgxGe (x = 4 %, 8 %, and 12 %) for photodetector and other electronic applications. First principles are applied to every calculation performed in the context of DFT. The generalized gradient approximation with the Hubbard potential included (GGA + U) has been chosen as the appropriate approximation to handle systems with strongly coupled electrons. The semi-metallic parental MnNiGe and doped MnNi1-xAgxGe (x = 4 %, 8 %, and 12 %) is ideal for conducting materials in electronics due to band overlapping, according to our findings. Degenerate doping of Ag into MnNiGe includes spinning the Fermi level, changing the DOS profile, and reducing the density of Fermi level states that allow tunneling from the valence band to the conduction band. An important part of this research is analyzing the refractive index, reflectivity, extinction coefficient, dielectric function, absorption coefficient, and energy loss function of parental MnNiGe and doped MnNi1-xAgxGe (x = 4 %, 8 %, and 12 %). According to our findings, it is possible to create a photo detector based on MnNi1-xAgxGe (x = 4 %, 8 %, and 12 %) that can detect light in the visible range (below 500 nm). It has also been found that the MnNi1-xAgxGe (x = 4 %, 8 %, and 12 %) exhibits the highest sensitivity to light with a wavelength of 450 nm. Due to its advantageous optical characteristics in the visible and ultraviolet regions, this material could be useful for the development of numerous optoelectronic applications.

Chemical effect of alkaline-earth metals (Be, Mg, Ca) substitution of BFe2XH hydride perovskites for applications as hydrogen storage materials: A DFT perspective

This study investigated the effect of alkaline-earth metals (X = Be, Mg, Ca) substitution of BFe2XH perovskite materials and the potential applications for hydrogen storage utilizing density functional theory (DFT) approach at the GGA-PBE and the HSE06 methods. The mechanical properties of the studied systems demonstrate the mechanical stability of BFe2MgH, making it the most mechanically robust compound. While the Pugh ratio suggests that BFe2BeH was brittle, while BFe2CaH showed greater ductility, anisotropic factors confirm that all compounds are anisotropic, indicating directional dependence in their properties. The electronic band structure analysis using the HSE06 and the GGA-PBE suggests that the studied perovskites are metallic due to a calculated bandgap of zero. In terms of optical/optoelectronic properties, BFe2MgH exhibits the highest optical conductivity, absorption coefficient, and energy loss function, indicating its superior ability to absorb light and transfer electrons. For practical applications, the hydrogen storage capacity is assessed, with BFe2BeH showing the highest gravimetric and volumetric capacities. These promising results suggest the potential use of BFe2BeH as an efficient material for hydrogen storage.

Auxological Status of Modern Primary School Students of Nizhny Novgorod Region

The article describes the characteristics of the resulting effector auxological morpho-functional status of primary school students, differentiated by gender and administrative-territorial characteristics. The objectives of the study included studying the auxological status of children adolescents, and primary school students in the Nizhny Novgorod region in the context of the peculiarities of the exoenvironment of residence in urban and rural areas. Materials and methods: Own data served as a source of anthropometry and physiometry indicators of the objective population of the region. The analysis of anthropological indicators was carried out by discretizing data sets that state an objective picture of auxological indicators at the regional level, taking into account the peculiarities of anthropogenic loads characteristic of the place of residence of the observed population groups. To quantify the values ​​and statistical differences in indicators by age, gender, and administrative characteristics, the median, standard deviation, and criteria were used: Fisher, Wilks, and Mahalanobis, with an error of differences at p < 0.05. Results: The stability of the age-sex evolution of auxological indicators is shown; the age-sex and territorial dimorphism of total body sizes is shown at 7-10 years of age, with residents of rural areas lagging in the observed indicators. Hemodynamic indicators in both boys and girls significantly prevail among students living in the metropolis relative to their rural counterparts, except diastolic blood pressure. Variance analytics shows differences in the distributions of anthropometry and hemodynamics, both by age and by the urbanization factor at p < 0.001. In the observed age period, at the initial stage, hemodynamic indicators act primarily as modifiers of the metropolis and rural groups. From the age of ten, according to the standardized coefficients of discriminant functions, according to the first canonical variable, the division of series also occurs according to anthropometric characteristics, among which the greatest contribution to the division of groups is made by body weight and body length, and the hemodynamic characteristic - diastolic blood pressure - has also proven to be decisive. Conclusion: Primary school students living in rural areas and in the metropolis of the Nizhny Novgorod region determine the observed indicators ambiguously; if residents of the metropolis state greater results for all observed auxological indicators, then rural peers demonstrate, while lagging in all observed indicators, greater indicators of diastolic blood pressure, which suggests a strain on adaptation mechanisms central character.

Dissecting the Superior Drivers for the Simultaneous Improvement of Fiber Quality and Yield Under Drought Stress Via Genome-Wide Artificial Introgressions of Gossypium barbadense into Gossypium hirsutum.

Global water scarcity and extreme weather intensify drought stress, significantly reducing cotton yield and quality worldwide. Drought treatments are conducted using a population of chromosome segment substitution lines generated from E22 (G. hirsutum) and 3-79 (G. barbadense) as parental lines either show superior yields or fiber quality under both control and drought conditions. Fourteen datasets, covering 4 yields and 4 quality traits, are compiled and assessed for drought resistance using the drought resistance coefficient (DRC) and membership function value of drought resistance (MFVD). Genome-wide association studies, linkage analysis, and bulked segregant analysis are combined to analyze the DR-related QTL. A total of 121 significant QTL are identified by DRC and MFVD of the 8 traits. CRISPR/Cas9 and virus-induced gene silencing techniques verified DRR1 and DRT1 as pivotal genes in regulating drought resistant of cotton, with hap3-79 exhibiting greater drought resistance than hapE22 concerning DRR1 and DRT1. Moreover, 14 markers with superior yield and fiber quality are selected for drought treatment. This study offers valuable insights into yield and fiber quality variations between G. hirsutum and G. barbadense amid drought, providing crucial theoretical and technological backing for developing cotton varieties resilient to drought, with high yield and superior fiber quality.

Electronic and optical characteristics of CaLiX3 (X = Cl, Br, I) perovskite compounds using the Tran–Blaha modified Becke–Johnson potential

We present the results of a comprehensive investigation using the full-potential linearized augmented plane wave approach to analyze the structural characteristics, electronic structures, and optical spectra of the perovskite compounds CaLiX3 (X = Cl, Br, or I). Various functionals were employed to simulate the exchange–correlation interactions. The calculated equilibrium structural parameters, obtained using the generalized gradient approximation, are consistent with the existing findings in the literature. The computed electronic structures reveal that the Tran–Blaha modified Becke–Johnson potential significantly enhances the bandgap. For all CaLiX3 compounds studied, we predicted an indirect bandgap. Additionally, we observed a gradual decrease in the bandgap as the atomic size of the X element increases. The electronic states constituting the various energy bands were evaluated by computing the partial and total densities of states. In addition, we computed a variety of optical spectra, including the complex dielectric function, absorption coefficient, refractive index, extinction coefficient, reflectivity, and electron energy loss function. The results demonstrate that a decrease in the bandgap leads to an increase in the zero-frequency limit of the dielectric function ε(0). The origins of the peaks and structures in the optical spectra were identified.

Simple proofs of certain inequalities with logarithmic coefficients of univalent functions

In this paper, we give simple proofs for the bounds (some of them sharp) of the difference of the moduli of the second and the first logarithmic coefficient for the general class of univalent functions and for the class of convex univalent functions.

Locally sparse and robust partial least squares in scalar-on-function regression

We present a novel approach for estimating a scalar-on-function regression model, leveraging a functional partial least squares methodology. Our proposed method involves computing the functional partial least squares components through sparse partial robust M regression, facilitating robust and locally sparse estimations of the regression coefficient function. This strategy delivers a robust decomposition for the functional predictor and regression coefficient functions. After the decomposition, model parameters are estimated using a weighted loss function, incorporating robustness through iterative reweighting of the partial least squares components. The robust decomposition feature of our proposed method enables the robust estimation of model parameters in the scalar-on-function regression model, ensuring reliable predictions in the presence of outliers and leverage points. Moreover, it accurately identifies zero and nonzero sub-regions where the slope function is estimated, even in the presence of outliers and leverage points. We assess our proposed method’s estimation and predictive performance through a series of Monte Carlo experiments and an empirical dataset—that is, data collected in relation to oriented strand board. Compared to existing methods our proposed method performs favorably. Notably, our robust procedure exhibits superior performance in the presence of outliers while maintaining competitiveness in their absence. Our method has been implemented in the robsfplsr package in .

Do local government investment preferences influence renewable energy technology innovation? Evidence from China

Local government investment can influence renewable energy technology innovation (RETI). Based on the panel data of 30 provinces in China from 2007 to 2019, this paper uses fixed effect models, partial linear generalized function coefficient models, and other methods to test the impact of local government investment preferences (LGIP) on RETI. The results are: (1) Productive investment preferences significantly inhibit RETI. (2) The impact of productive investment preferences on RETI is heterogeneous across economic development stages and regions. (3) With economic growth, the negative impact of productive investment preferences on RETI gradually decreases. The findings suggest that local governments should adjust investment patterns and appropriately reduce productive investment to improve RETI.

Investigating structural and optoelectronic properties of Cr-substituted ZnSe semiconductors

The optoelectronic and structural characteristics of the Zn1−xCrxSe (0 ≤ x ≤ 1) semiconductor are reported by employing density functional theory (DFT) within the mBJ potential. The findings revealed that the lattice constant decreases with increasing Cr concentration, although the bulk modulus exhibits the opposite trend. ZnSe is a direct bandgap material; however, a change from direct to indirect electronic bandgap has been seen with Cr presence. This transition is caused by structural alterations by Cr and defects forming, which results in novel optical features, including electronic transitions. The electronic bandgap decreases from 2.769 to 0.216 eV, allowing phonons to participate and improving optical absorption. A higher concentration of Cr boosts infrared absorption and these Cr-based ZnSe (ZnCrSe) semiconductors also cover a wider spectrum in the visible range from red to blue light. Important optical parameters such as reflectance, optical conductivity, optical bandgap, extinction coefficient, refractive index, magnetization factor, and energy loss function are discussed, providing a theoretical understanding of the diverse applications of ZnCrSe semiconductors in photonic and optoelectronic devices.

Investigating the optical properties and electronic structure of gallium phosphide nanotubes doped with arsenic via implementing first-principles calculations.

This study investigates the impact of arsenic doping on the optical characteristics and electronic structure of zigzag (8, 0) and armchair (4, 4) gallium phosphide nanotubes using first-principles calculations based on the GaP1-xAsx system, where x = 0, 0.25, 0.5, 0.75, and 1. The electronic calculations showed that doping more arsenic atoms reduces the energy band gap for zigzag and armchair GaPAs nanotubes. PDOS analysis indicates that Ga-4p and P-3p orbitals play a significant role in determining the electronic properties of the GaP nanotube. The dominance of Ga-4p and P-3p orbitals in both the valence and conduction bands indicates their importance across the energy spectrum of the material. The complex dielectric function and absorption coefficient of zigzag and armchair GaP1-xAsx nanotubes are calculated for incident radiation with energies ranging from 1 to 6.2eV. Optical results revealed that both zigzag and armchair GaPNTs exhibit strong absorption in the UV-visible regions due to electronic transitions between different Van Hove singularities. Also, due to quantum confinement effects, pure zigzag gallium phosphide nanotube exhibited two absorption edges at wavelengths (273 and 375nm). These edges stand from the energy level's quantization in the nanotube construction, affecting the absorption characteristics. Substitutional doping by arsenic atoms changes the absorption edge to the long wavelengths due to decreased bandgap energy. Investigating electronic structures and optical properties of nanotubes proposes several advantages, such as understanding the doping effects on the nanotube structure and contributing to the direction of the experimental studies. These computational studies play a key role in developing the applications of nanomaterials. Calculations of density functional theory (DFT) are achieved via the SIESTA package. SIESTA is a powerful and effective tool for executing DFT calculations on a large system of atoms. It generates numerous output files covering detailed information about the electronic structure, optical properties, total energy, optimized geometry, and other computed properties. The generalized gradient approximation GGA with Perdew-Burke-Ernzerhof PBE functional was used. A vacuum region of 10 A0 was applied to avoid the interactions of adjacent nanotubes.

Insights into the optoelectronic and thermoelectric properties of defect chalcopyrites XAl2Se4 (X = Zn, Cd, and Hg): A density functional theory approach

In the current study, we employed the full-potential linearized augmented plane wave plus local orbitals (FP-LAPW + lo) approach within the density functional theory (DFT) to investigate the physical properties of Defect Chalcopyrites XAl2Se4 (X = Zn, Cd, and Hg). Calculations yield precise structural and electronic parameters in good agreement with experimental data, revealing all three compounds as direct wide-bandgap semiconductors. The modified Becke-Johan potential (TB-mBJ) method accurately estimates energy gaps, which increase with decreasing lattice constants. The calculated values are 3.34 eV, 3.12 eV, and 2.30 eV for ZnAl2Se4, CdAl2Se4, and HgAl2Se4, respectively. The optical properties, including dielectric function and absorption coefficient, indicate potential applications in visible and ultraviolet optoelectronic devices. The high anisotropy of these materials further enhances their suitability for a range of linear and nonlinear optical applications. Moreover, ZnAl2Se4 exhibits the highest Seebeck coefficient at room temperature. The positive Seebeck coefficient confirmed the p-type behavior of the studied compounds. The highest observed power factor demonstrates optimal thermoelectric performance for these materials. High electrical conductivity values suggest their suitability as effective electrical conductors, especially at elevated temperatures. This study encourages further research into defect chalcopyrites for applications in optoelectronics and thermoelectric energy conversion.

Fractional Differential Operator Based on Quantum Calculus and Bi-Close-to-Convex Functions

In this article, we first consider the fractional q-differential operator and the λ,q-fractional differintegral operator Dqλ:A→A. Using the λ,q-fractional differintegral operator, we define two new subclasses of analytic functions: the subclass S*q,β,λ of starlike functions of order β and the class CΣλ,qα of bi-close-to-convex functions of order β. We explore the results on coefficient inequality and Fekete–Szegö problems for functions belonging to the class S*q,β,λ. Using the Faber polynomial technique, we derive upper bounds for the nth coefficient of functions in the class of bi-close-to-convex functions of order β. We also investigate the erratic behavior of the initial coefficients in the class CΣλ,qα of bi-close-to-convex functions. Furthermore, we address some known problems to demonstrate the connection between our new work and existing research.