Correction Term Research Articles

Exploring the Nexus between Macroeconomic Variables and Stock Market Returns in Nepal: An ARDL Bounds Testing Approach

Background: Investors and policymakers must understand how macroeconomic variables (MEVs) affect stock market behavior to maximize portfolios and maintain economic stability. Hence, it is crucial to establish a nexus between MEVs and stock market returns (SMRs). Objectives: This study seeks to assess the effects of MEV on SMRs in the long and short run. Methods: This paper analyzed the cointegrating relationship between MEVs and SMRs using a time series data set from 1994 to 2023. This study used the ARDL bounds testing approach. Results: The results confirm a cointegrating association between MEVs and SMRs in the Nepalese stock market. The error correction (ECT -1) term is significantly negative, suggesting a persistent correlation between the variables. The study also shows that interest rates negatively affect SMRs over time. Real GDP (LRGDP), inflation (LINFR), and exchange rate (LEXR) have negative but statistically insignificant associations with SMRs. However, the money supply (LMS) positively correlates with SMRs. Conclusion: The study’s findings provide practical advice for policymakers. For instance, lower interest rates increase the appeal of stocks by reducing the opportunity costs of holding bank deposits and credit costs. Therefore, policymakers are advised to maintain lower interest rates to cultivate a more appealing investment environment. Furthermore, policymakers should prioritize regulating inflation and preserving a robust foreign exchange rate to boost investors’ SMRs.

Trade Liberalization, Foreign Investment and Economic Growth: Experience from Non-Oil Producing Countries in Africa

This study focuses on trade liberalization, foreign investment and economic growth in non-oil-producing countries of Africa using the panel autoregressive distributed lag (ARDL) model. Annual time series data spanning from 2000 to 2023. The study reveals a strong long-term relationship between trade liberalization, foreign direct investment (FDI), and economic growth in non-oil-producing African countries. This finding is evidenced by the rejection of the “no long-run relationship” hypothesis, indicating a solid and enduring connection among these factors, which aligns with previous research. Most variables conform to theoretical expectations, supporting the hypothesis that trade liberalization and FDI contribute positively to economic growth. However, FDI and exchange rates exhibit unexpected deviations, likely reflecting structural challenges common in non-oil African economies, such as barriers that limit stable FDI inflows and hinder sustainable growth. The error correction term (ECT) further suggests that these economies adjust quickly from deviations, with respective short-run adjustment rates of 90%, 10%, and 50% in different model specifications. This high responsiveness indicates that, despite short-term disruptions, these economies tend to revert swiftly to their long-term growth trajectories. Based on the findings, we recommend that policies should be directed towards the pursuit of consistent and sustainable trade liberalization by reducing trade barriers, and reduction of obstacles to foreign investment to improve economic growth in non-oil-producing countries of Africa.

Interpolation of compound semiconductor alloy parameters from those of their constituents

Several methods have been proposed for interpolation of the value of physical parameters of quaternary alloys from those of their constituent ternary and binary sub-alloys. These expressions agree when non-linear bowing terms are not required; they differ in how the bowing terms of the bounding ternaries should be utilized. Common interpolation expressions for quaternaries can be generalized into two groups: (1) those that use a linear interpolation of the nearest ternary parameter values and (2) those that interpolate over binary values with a bowing term derived from the bounding ternaries. The second group of methods is equivalent to a polynomial expansion over the alloy’s interpolation space. For compound semiconductor alloys, the geometry of the composition space is the direct sum of the group-III and group-V mixture sub-spaces. The mixture sub-spaces are best described using barycentric coordinates on a regular simplex. A general polynomial expansion of the value of an alloy parameter using barycentric coordinates for the group-III and group-V simplex spaces is described along with an algorithm to generate interpolation expressions for alloys with arbitrary numbers of elements, including quinary and senary alloys. It is shown that a polynomial expansion produces values in closer agreement with the direct gap of quaternaries lattice-matched to common substrates than do approaches using an interpolation of the ternary values, despite a prominent recommendation to the contrary. Finally, a quaternary correction term is described that improves the predicted direct bandgap energies of GaInAsSb for compositions near those lattice matched to InP, InAs, and GaSb.

Constraints on dark matter mass in an F(R) gravity model with an additional R2 correction term

Abstract The dominance of dark matter and dark energy presents one of the most significant challenges in cosmology. The chameleon mechanism in F(R) gravity offers a potential solution to this issue. However, many F(R) models encounter a problem known as the singularity problem, where the scalaron mass becomes too heavy to function as dark matter. This study aims to address the singularity problem within the Gogoi-Goswami F(R) model by incorporating an additional R 2 correction term. Assuming the scalaron functions as chameleonic dark matter, its mass must satisfy constraints across various scales, including the electroweak transition phase and galactic structures. By adopting a hierarchical scale with R 0 ≪ R c < m ¯ 2 , where R 0 is the Ricci scalar at late-time de Sitter space and m ¯ represents the inflaton mass scale in Starobinsky's model, and assuming R c ≃ 1 GeV2, the mass constraints during the electroweak transition can be satisfied with α ≃ 1.05. Nevertheless, meeting the required mass constraints on a galactic scale remains a challenge. Alternatively, if R c is considered relevant only in the current universe, such that R 0 ≪ R c ≪ m ¯ 2 , these dark matter mass constraints can be more easily met. For example, setting R c ≃ m φ 2 ( gal ) ≃ ( 1 0 − 32 ) 2 GeV 2 effectively satisfies these constraints.

Cross-Sections for Projectile Ionization, Electron Capture, and System Breakdown of C5+ and Li2+ Ions with Atomic Hydrogen

For many disciplines of science, all conceivable collisional cross-sections and reactions must be precisely known. Although recent decades have seen a trial of large-scale research to obtain such data, many essential atomic and molecular cross-section data are still missing, and the reliability of the existing cross-sections has to be validated. In this paper, we present projectile ionization, electron capture, and system breakdown cross-sections in carbon (C5+) ions and lithium (Li2+) ion collisions with atomic hydrogen based on the Monte Carlo models of classical and quasi-classical trajectories. According to our expectation, the QCTMC results show higher results in comparison to standard CTMC data, emphasizing the role of the Heisenberg correction constraint, especially in the low-energy regime. On the other hand, at high energy, the Heisenberg correction term has less influence as the projectile momentum increases. We present the total cross-sections of projectile ionization, electron capture, and system breakdown in C5+ ions and Li2+ ion collisions with atomic hydrogen in the impact energy range from 10 keV to 160 keV, which is of interest in astrophysical plasmas, atmospheric sciences, plasma laboratories, and fusion research.

Gaussian approximation and moderate deviations of Poisson shot noises with application to compound generalized Hawkes processes

Abstract In this article, we give explicit bounds on the Wasserstein and Kolmogorov distances between random variables lying in the first chaos of the Poisson space and the standard normal distribution, using the results of Last et al. (Prob. Theory Relat. Fields165, 2016). Relying on the theory developed by Saulis and Statulevicius in Limit Theorems for Large Deviations (Kluwer, 1991) and on a fine control of the cumulants of the first chaoses, we also derive moderate deviation principles, Bernstein-type concentration inequalities, and normal approximation bounds with Cramér correction terms for the same variables. The aforementioned results are then applied to Poisson shot noise processes and, in particular, to the generalized compound Hawkes point processes (a class of stochastic models, introduced in this paper, which generalizes classical Hawkes processes). This extends the recent results of Hillairet et al. (ALEA19, 2022) and Khabou et al. (J. Theoret. Prob.37, 2024) regarding the normal approximation and those of Zhu (Statist. Prob. Lett.83, 2013) for moderate deviations.

Challenges for low-carbon economies in Latin America. Testing pollution haven hypothesis in developing countries

Our research investigates the determinants of CO₂ emissions in Latin American countries (LAC), focusing on the roles of renewable energy consumption (RENC), economic growth (GDP), foreign direct investment (FDI), urbanization (URB), and access to electricity (ACEL). Employing a panel ARDL model, we account for both short-run and long-run dynamics between CO₂ emissions and their determinants. In the long run, RENC demonstrates a significant negative impact on CO₂ emissions (-0.15). Higher-order terms of RENC reveal non-linear effects, with RENC² showing a positive coefficient (0.05) and RENC³ a negative coefficient (-0.006), indicating diminishing returns as renewable energy consumption increases. Economic growth is positively associated with CO₂ emissions (0.1), reflecting the trade-off between economic expansion and environmental sustainability. FDI has a small but significant negative impact on emissions (-0.0003), while ACEL also reduces emissions (-0.03). In the short run, CO₂ emissions adjust to long-run equilibrium at a rate of -0.04, with GDP exerting the strongest short-run influence. The Energy Kuznets Hypothesis for CO₂ emissions is found to be a monotonically decreasing function of RENC, implying that as RENC increases, CO₂ emissions consistently decrease, albeit at a slower rate. The error correction term (ECT) is negative and significant (-0.04), indicating that CO₂ emissions adjust towards the long-run equilibrium by about 4% each period. The Dumitrescu-Hurlin panel causality test confirms bidirectional causality between RENC and CO₂ emissions. Unidirectional causality is also observed from URB to CO₂ emissions and from CO₂ to ACEL. Variations in energy consumption profiles and stages of economic development across the region explain differing impacts of RENC and FDI on emissions, where some countries experience the pollution haven effect, while others benefit from the pollution halo.

The Effect of the Correction Term on the Equation of State of the Asymmetric Nuclear Matter(ANM) within the Bruckner-Hartree-Fock Approach

The Effect of the Correction Term on the Equation of State of the Asymmetric Nuclear Matter(ANM) within the Bruckner-Hartree-Fock Approach

High-precision measurements of the atomic mass and electron-capture decay Q value of 95Tc

A direct measurement of the ground-state-to-ground-state electron-capture decay Q value of 95Tc has been performed utilizing the double Penning trap mass spectrometer JYFLTRAP. The Q value was determined to be 1695.92(13) keV by taking advantage of the high resolving power of the phase-imaging ion-cyclotron-resonance technique to resolve the low-lying isomeric state of 95Tc (excitation energy of 38.910(40) keV) from the ground state. The mass excess of 95Tc was measured to be −86015.95(18) keV/c2, exhibiting a precision of about 28 times higher and in agreement with the value from the newest Atomic Mass Evaluation (AME2020). Combined with the nuclear energy-level data for the decay-daughter 95Mo, two potential ultra-low Q-value transitions are identified for future long-term neutrino-mass determination experiments. The atomic self-consistent many-electron Dirac–Hartree–Fock–Slater method and the nuclear shell model have been used to predict the partial half-lives and energy-release distributions for the two transitions. The dominant correction terms related to those processes are considered, including the exchange and overlap corrections, and the shake-up and shake-off effects. The normalized distribution of the released energy in the electron-capture decay of 95Tc to excited states of 95Mo is compared to that of 163Ho currently being used for electron-neutrino-mass determination.

Estimation of multicomponent reactions’ yields from networks of mechanistic steps

This work describes estimation of yields of complex, multicomponent reactions (MCRs) based on the modeled networks of mechanistic steps spanning both the main reaction pathway as well as immediate and downstream side reactions. Because experimental values of the kinetic rate constants for individual mechanistic transforms are extremely sparse, these constants are approximated here using Mayr’s nucleophilicity and electrophilicity parameters fine-tuned by correction terms grounded in linear free-energy relationships. With this formalism, the model trained on the mechanistic networks of only 20 – but mechanistically- and yield-diverse MCRs – transfers well to newly discovered MCRs that are based on markedly different mechanisms and types of individual mechanistic transforms. These results suggest that mechanistic-level approach to yield estimation may be a useful alternative to models that are derived from full-reaction data and lack information about yield-lowering side reactions.

Online public opinion prediction based on a novel conformable fractional discrete grey model

PurposeAs social networks have developed to be a ubiquitous platform of public opinion spreading, it becomes more and more crucial for maintaining social security and stability by accurately predicting various trends of public opinion dissemination in social networks. Considering the fact that the dissemination of online public opinion is a dynamic process full of uncertainty and complexity, this study establishes a novel conformable fractional discrete grey model with linear time-varying parameters, namely the CFTDGM(1,1) model, for more accurate prediction of online public opinion trends.Design/methodology/approachFirst, the conformable fractional accumulation and difference operators are employed to build the CFTDGM(1,1) model for enhancing the traditional integer-order discrete grey model with linear time-varying parameters. Then, to improve forecasting accuracy, a base value correction term is introduced to optimize the iterative base value of the CFTDGM(1,1) model. Next, the differential evolution algorithm is selected to determine the optimal order of the proposed model through a comparison with the whale optimization algorithm and the particle swarm optimization algorithm. The least squares method is utilized to estimate the parameter values of the CFTDGM(1,1) model. In addition, the effectiveness of the CFTDGM(1,1) model is tested through a public opinion event about “IG team winning the championship”. Finally, we conduct empirical analysis on two hot online public opinion events regarding “Chengdu toddler mauled by Rottweiler” and “Mayday band suspected of lip-syncing,” to further assess the prediction ability and applicability of the CFTDGM(1,1) model by comparison with seven other existing grey models.FindingsThe test case and empirical analysis on two recent hot events reveal that the CFTDGM(1,1) model outperforms most of the existing grey models in terms of prediction performance. Therefore, the CFTDGM(1,1) model is chosen to forecast the development trends of these two hot events. The prediction results indicate that public attention to both events will decline slowly over the next three days.Originality/valueA conformable fractional discrete grey model is proposed with the help of conformable fractional operators and a base value correction term to improve the traditional discrete grey model. The test case and empirical analysis on two recent hot events indicate that this novel model has higher accuracy and feasibility in online public opinion trend prediction.

Microscopic description of the pygmy and giant dipole resonances in even–even nuclei. Application to the isotopes 150,152,154,156,158,160Gd

This paper deals with a microscopic approach for the description of the pygmy dipole resonance (PDR) as well as of the giant dipole resonance (GDR). The formalism is based on a Hamiltonian which is summing a mean field term, the pairing for alike nucleons and the dipole–dipole interaction. Two features are specific for our description: (a) The use of a projected spherical single particle basis and (b) the involved dipole operator is a Schif-like operator including a corrective term which is cubic in the radial coordinate. The dipole strength distribution with energy is plotted for the PDR region, i.e., [0,10] MeV. The dominant transitions have an isovector character for three isotopes and isoscalar for another three. The PDR states carry only 0.4–1.8[Formula: see text] of the total EWSR. The dependence of the dipole strength on nuclear deformation is evidenced. For the whole interval of [0,20] MeV the dipole strength was first folded by Lorentzian of 1[Formula: see text]MeV width and then plotted as function of the QRPA energies. The peaks belonging to each of the two ranges are analyzed in detail and their nature, isovector/isoscalar, was pointed out. The r-cubic term and the nuclear deformation have opposite effects on the dipole strength. The famous Thomas–Reiche–Kuhn sum rule formula is generalized to the case of the Schiff dipole momentum. The new EWSR is very well satisfied. The photoabsorbtion cross-section is calculated and compared with experimental data in a figure showing its dependence on energy. The total cross-section, [Formula: see text], the moments of the integrated cross-sections, [Formula: see text], [Formula: see text], the dipole polarizability and the thickness of the neutron crust are also calculated. The main features of PDR and GDR are realistically described.

An experimental study of pressure drop characteristics under single‐phase flow through packed bed microreactors

AbstractPacked bed microreactors offer a promising platform for intensifying heterogeneously catalyzed reactions. To understand hydrodynamics therein, N2 or water flow was investigated experimentally through microreactors packed with glass beads in this work, corresponding to a microreactor to particle diameter ratio (D/d) of 1.29–25.12. The porosity of a single pellet string microreactor (D/d < 1.866) agrees with the literature's theoretical equation. For microreactors with larger D/d ratios, an empirical porosity correlation is proposed to address the dense packing nature of the bed. The existing correlations are inadequate to describe the pressure drop data in microreactors within the entire D/d ratios and modified Reynolds numbers (Rem < 291). At D/d ≥ 3, the measured pressure drop is described by the modified Ergun equation using properties of the bulk bed zone to exclude the wall effect. At D/d < 3, it can be predicted by introducing a correction term for the wall effect into the Ergun equation.

Universal scaling laws in quantum-probabilistic machine learning by tensor network towards interpreting representation and generalization powers

Abstract Interpreting the representation and generalization powers has been a long-standing issue in the field of machine learning (ML) and artificial intelligence. This work contributes to uncovering the emergence of universal scaling laws in quantum-probabilistic ML. We take the generative tensor network (GTN) in the form of a matrix product state as an example and show that with an untrained GTN (such as a random TN state), the negative logarithmic likelihood (NLL) $L$ generally increases linearly with the number of features $M$, i.e., $L \simeq k M + const$. This is a consequence of the so-called “catastrophe of orthogonality,” which states that quantum many-body states tend to become exponentially orthogonal to each other as $M$ increases. We reveal that while gaining information through training, the linear scaling law is suppressed by a negative quadratic correction, leading to $L \simeq \beta M - \alpha M^2 + const$. The scaling coefficients exhibit logarithmic relationships with the number of training samples and the number of quantum channels $\chi$. The emergence of the quadratic correction term in NLL for the testing (training) set can be regarded as evidence of the generalization (representation) power of GTN. Over-parameterization can be identified by the deviation in the values of $\alpha$ between training and testing sets while increasing $\chi$. We further investigate how orthogonality in the quantum feature map relates to the satisfaction of quantum probabilistic interpretation, as well as to the representation and generalization powers of GTN. The unveiling of universal scaling laws in quantum-probabilistic ML would be a valuable step toward establishing a white-box ML scheme interpreted within the quantum probabilistic framework.

Calculation of divergenceless magnetically induced current density in molecules

A method for the calculation of divergenceless, magnetically induced quantum mechanical current densities in molecules that approximates the exact current is presented. This was achieved by adding to the calculated conventional current density, i.e., a current that typically has a non-zero divergence, a corrective term that is the negative of the irrotational field of its Helmholtz decomposition. The solenoidal field of the decomposition is the divergence-free current density, which is still an approximation of the exact current but which now satisfies the continuity requirement regardless of the quality of the basis set. Based on calculations performed on several simple molecules (LiH, H2O, benzene, and zethrene), adopting different kinds of low-level theoretical approaches, clear improvements are observed in the correspondence of vortices, sources, and sinks for which the conventional current density shows a lack of continuity. A little improvement is also observed for the calculated diagonal components of the magnetizability tensor.

A theoretical derivation of slip boundary conditions based on the Cercignani–Lampis–Lord scattering model

To characterize fluid flow in the slip regime, the use of Navier–Stokes–Fourier (NSF) equations with slip boundary conditions is prevalent. This trend underscores the necessity of developing reliable and accurate slip boundary conditions. According to kinetic theory, slip behaviours are intrinsically linked to the gas scattering processes at the surface. The widely used Maxwell scattering model, which employs a single accommodation coefficient to describe gas scattering processes, reveals its limitations when the difference between accommodation coefficients in the tangential and normal directions becomes significant. In this work, we provide a derivation of velocity slip and temperature jump boundary conditions based on the Cercignani–Lampis–Lord scattering model, which applies two independent accommodation coefficients to describe the gas scattering process. A Knudsen layer correction term is introduced to account for the impact of the surface on the velocity distribution function, which is associated with the scattering model. The governing equation of the correction term is established based on the linearized Boltzmann equation. Additionally, two moments are derived to capture the collision effect in the Knudsen layer: a conserving moment of collision invariants, and an approximate higher-order conserving moment. These moments are then employed to determine the coefficients in the correction term. We demonstrate that the derived slip coefficients align closely with numerical results obtained by solving the Boltzmann equation in the Knudsen layer. Besides, we apply the derived slip boundary conditions within the framework of the NSF equations, yielding numerical results that exhibit excellent consistency with those obtained through molecular-level simulations.

A consistent diffuse-interface model for two-phase flow problems with rapid evaporation

We present accurate and mathematically consistent formulations of a diffuse-interface model for two-phase flow problems involving rapid evaporation. The model addresses challenges including discontinuities in the density field by several orders of magnitude, leading to high velocity and pressure jumps across the liquid–vapor interface, along with dynamically changing interface topologies. To this end, we integrate an incompressible Navier–Stokes solver combined with a conservative level-set formulation and a regularized, i.e., diffuse, representation of discontinuities into a matrix-free adaptive finite element framework. The achievements are three-fold: First, we propose mathematically consistent definitions for the level-set transport velocity in the diffuse interface region by extrapolating the velocity from the liquid or gas phase. They exhibit superior prediction accuracy for the evaporated mass and the resulting interface dynamics compared to a local velocity evaluation, especially for strongly curved interfaces.Second, we show that accurate prediction of the evaporation-induced pressure jump requires a consistent, namely a reciprocal, density interpolation across the interface, which satisfies local mass conservation. Third, the combination of diffuse interface models for evaporation with standard Stokes-type constitutive relations for viscous flows leads to significant pressure artifacts in the diffuse interface region. To mitigate these, we propose to introduce a correction term for such constitutive model types. Through selected analytical and numerical examples, the aforementioned properties are validated. The presented model promises new insights in simulation-based prediction of melt–vapor interactions in thermal multiphase flows such as in laser-based powder bed fusion of metals.

A momentum-conserving wake superposition method for wind-farm flows under pressure gradient

Pressure gradient over topography will significantly affect wind-farm flow. However, knowledge gaps still exist on how to superpose wind-turbine wakes in the wind-farm flow analytical model to account for this effect, leading to systematic errors in evaluating wind-farm wake effects. To this end, we derive an implicit momentum-conserving wake superposition method under pressure gradient (PG-IMCM) based on the total momentum deficit equation, which is linearised by the convection velocity introduced by Zong & Porté-Agel (J. Fluid Mech., vol. 889, 2020, A8). The PG-IMCM method consists of the linear-weighted sum of individual velocity deficits, the sum of the individual pressure correction terms and the total pressure correction term. Based on a sensitivity analysis, we demonstrate that the last two terms nearly cancel out and, thus, can be neglected, resulting in a simplified form, which has the same form as its counterpart under zero pressure gradient but with the single-wake quantities redefined based on the wake model under pressure gradient. This motivates us to further examine the performance of the combination of five empirical superposition methods and the stand-alone wake model under pressure gradient. Validation results based on large-eddy simulation show that PG-IMCM has an overall satisfactory performance in both the magnitude and shape of the velocity-deficit profiles, provided that the stand-alone turbine wake can be modelled accurately, which is virtually identical with its simplified form. Further comparison with empirical superposition methods shows that local linear and wind product superposition methods based on the updated base flow also have comparable performance, with only discernable differences with the PG-IMCM method in the near-wake region of downstream turbines. Therefore, they are two attractive methods for engineering applications.

"Vulva," Not "Private Part": The Importance of Accurate Genital Terminology.

Effective communication in pediatric dermatology is critical for accurate diagnosis and treatment, particularly in sensitive areas such as the anogenital region. Unfortunately, children and their families often use euphemisms or incorrect terms when referring to this area, and many adults lack knowledge of anogenital terminology. Pediatric dermatologists can play a unique role in educating children and their families on correct anatomical language, which enhances body awareness, empowers young patients, improves safety, and contributes to accurate medical assessments and treatment adherence. By promoting the use of correct anatomical terms, pediatric dermatologists can improve patient outcomes and foster a healthier understanding of body anatomy and health.

Triaxial deformation, shell structure, shell corrections and the connection to alpha-clustering in nuclei

Abstract We explore the connection between the appearance of quasi-stable structures in mean-field type calculations, which arise as a result of the evolution of the underlying shell structure as a function of deformation, and α-clustering in light even–even nuclei. The Nilsson–Strutinsky mean-field approach employs a macroscopic liquid-drop whose energy is modified by a shell correction term derived using the Strutinsky method. This method reflects the variations in the energies of the single-particle states with deformation. As such, there is no obvious connection to clustering. Here we use the changing level scheme of the deformed harmonic oscillator as a function of triaxial deformation to fully explore the variation in stability of α-cluster structures in light even–even nuclei. The energies of the harmonic oscillator levels are used to deduce the energy required to disrupt the α-cluster as a function of the triaxial deformation. We find that there is good agreement between variations in the shell correction energy in the mean-field method and the energy required to disrupt the α-cluster. This provides a necessary link between understanding of the appearance of quasi-stable α-cluster structures and quasi-stable shapes appearing in mean-field calculations.