Results 71 to 80 of about 813 (192)

Closed-form estimators for the inverse Nakagami distribution

Anais da Academia Brasileira de Ciências
The inverse Nakagami distribution due to Louzada et al. (2018) does not have closed-form maximum likelihood estimators. Closed-form estimators by adapting the method of moments are proposed in this note.
VICTOR NAWA, SARALEES NADARAJAH
doaj   +1 more source

Optimal Control Strategies and Continuous Dependence for Stochastic Hilfer Fractional Systems With Delay: A Volterra‐Fredholm Integro‐Differential Approach

Optimal Control Applications and Methods, Volume 46, Issue 6, Page 2708-2726, November/December 2025.
The graphical abstract highlights our research on Sobolev Hilfer fractional Volterra‐Fredholm integro‐differential (SHFVFI) control problems for 1<ϱ<2$$ 1<\varrho <2 $$. We begin with the Hilfer fractional derivative (HFD) of order (1,2) in Sobolev type, which leads to Volterra‐Fredholm integro‐differential equations.
Marimuthu Mohan Raja, V. Vijayakumar, Chun‐Wei Tsai, Kalyana Chakravarthy Veluvolu   +3 more
wiley   +1 more source

Asymmetric stable stochastic volatility models: estimation, filtering, and forecasting

Journal of Time Series Analysis, Volume 46, Issue 6, Page 1098-1124, November 2025.
This article considers a stochastic volatility model featuring an asymmetric stable error distribution and a novel way of accounting for the leverage effect. We adopt simulation‐based methods to address key challenges in parameter estimation, the filtering of time‐varying volatility, and volatility forecasting.
Francisco Blasques, Siem Jan Koopman, Karim Moussa   +2 more
wiley   +1 more source

From OPE to chiral perturbation theory in holographic QCD

EPJ Web of Conferences, 2016
The soft wall model in holographic QCD has Regge trajectories but wrong operator product expansion (OPE) for the two-point vectorial QCD Green function. We modify the dilaton potential to comply with the OPE.
Cappiello Luigi, D’Ambrosio Giancarlo, Greynat David   +2 more
doaj   +1 more source

Pole decomposition of BFKL eigenvalue at zero conformal spin and the real part of digamma function [PDF]

, 2023
Mohammad Joubat, Claudelle Capasia Madjuogang Sandeu, Alex Prygarin   +2 more
openalex   +1 more source

Estimation and Inference for Higher‐Order Stochastic Volatility Models With Leverage

Journal of Time Series Analysis, Volume 46, Issue 6, Page 1064-1084, November 2025.
ABSTRACT Statistical inference—estimation and testing—for stochastic volatility models is challenging and computationally expensive. This problem is compounded when leverage effects are allowed. We propose efficient, simple estimators for higher‐order stochastic volatility models with leverage [SVL(p)$$ (p) $$], based on a small number of moment ...
Md. Nazmul Ahsan, Jean‐Marie Dufour, Gabriel Rodriguez‐Rondon   +2 more
wiley   +1 more source

Harmonic Growth—The Harmonic Number Applied to ROI, Business Scaling, Nth Plant Economics, Micro Combined Heat and Power (mCHP), Biorefineries, and Biochar Production

Mathematical Methods in the Applied Sciences, Volume 48, Issue 15, Page 13999-14013, October 2025.
ABSTRACT Scaling is a topic of utmost importance in business. When to scale and how has been the subject of countless books and seminars. This paper looks at modular businesses that have income and costs directly proportional to the number of units.
Micah N. Jasper
wiley   +1 more source

Monotonicity and positivity of several functions involving ratios and products of polygamma functions

Journal of Inequalities and Applications
Let ψ ( x ) $\psi (x)$ denote the digamma function, that is, the logarithmic derivative of the classical Euler gamma function Γ ( x ) $\Gamma (x)$ . In the paper, the authors discover the monotonic properties of the functions ψ ( n ) ( x ) x ψ ( n + 1 ) (
Feng Qi, Dongkyu Lim, Kwara Nantomah
doaj   +1 more source

New fractional estimates for Hermite-Hadamard-Mercer’s type inequalities

Alexandria Engineering Journal, 2020
An analogous version of Hermite-Hadamard-Mercer’s inequality has been established using the Katugampola fractional integral operators. The result is the generalization of the Riemann-Liouville fractional integral operator combined with the left and right
Hong-Hu Chu, Saima Rashid, Zakia Hammouch, Yu-Ming Chu   +3 more
doaj   +1 more source

Green Urea Synthesis from CO2 and Nitrogenous Small Molecules via Electrocatalysis and Photocatalysis

Small Science, Volume 5, Issue 10, October 2025.
Electrocatalysis and photocatalysis offer electron‐driven parallel routes for green urea synthesis from CO2 and nitrogenous small molecules (N2, NO3−, NO2−, and NO), providing sustainable alternatives to Bosch–Meiser process. Gaining in‐depth insights into the underlying mechanisms, efficiency, selectivity, and techno‐economic analysis of ...
Lizhen Liu, Lin Zhou, Longcheng Zhang, Hongwei Huang, Xin Zhao, Zhichuan J. Xu   +5 more
wiley   +1 more source