Results 41 to 50 of about 14,555 (148)

A new approach to fluctuations of reflected L\'{e}vy processes [PDF]

, 2010
We present a new approach to fluctuation identities for reflected L\'{e}vy processes with one-sided jumps. This approach is based on a number of easy to understand observations and does not involve excursion theory or It\^{o} calculus.
Ivanovs, Jevgenijs
core  

Advanced control of non‐isothermal axial dispersion tubular reactors with recycle‐induced state delay

The Canadian Journal of Chemical Engineering, EarlyView.
Abstract We develop a delay‐aware estimation and control framework for a non‐isothermal axial dispersion tubular reactor modelled as a coupled parabolic‐hyperbolic PDE system with recycle‐induced state delay. The infinite‐dimensional dynamics are preserved without spatial discretization by representing the delay as a transport PDE and adopting a late ...
Behrad Moadeli, Stevan Dubljevic
wiley   +1 more source

q-Invariant Functions for Some Generalizations of the Ornstein-Uhlenbeck Semigroup [PDF]

, 2008
We show that the multiplication operator associated to a fractional power of a Gamma random variable, with parameter q>0, maps the convex cone of the 1-invariant functions for a self-similar semigroup into the convex cone of the q-invariant functions for
Patie, P.
core   +1 more source

Highly Efficient and Salt‐Tolerant Broom‐like Bamboo Solar Evaporator: Constructing Multiscale Open Gaps to Enhance Water Transportation and Vapor Diffusion

ENERGY &ENVIRONMENTAL MATERIALS, EarlyView.
A bamboo fiber aggregation‐based broom‐like evaporator with open interstitial spaces for water transport and vapor diffusion was designed that provided extensive air–liquid interfaces for facilitating fast vapor diffusion and avoiding the formation of high‐humidity zones.
Rilong Yang, Yuying Yang, Qianwen Liu, Qiuhua Feng, Jianyu Wu, Yan Yu   +5 more
wiley   +1 more source

Advanced Virtual Impedance for Power‐Sharing Improvement in Microgrids Using Different SOGI Methods: A Comparative Study

Energy Technology, EarlyView.
Advanced virtual impedance control integrating multiple second‐order generalized integrator (SOGI) variants—SOGI, ESOGI, MSOGI, and DSOGI—enhances power and harmonic sharing accuracy in islanded microgrids. The comparative study quantifies performance–complexity trade‐offs, demonstrating up to 65% total harmonic distortion (THD) reduction and improved ...
Camelia Ait Hammouda, Abdellah Benallal, Rafik Bradai, Adrian Ilinca   +3 more
wiley   +1 more source

Improving the Characteristics of the Direct FOC Strategy in DFIG‐Based Wind Turbine Systems Using FOIDD and FOPD Controllers

Energy Science &Engineering, EarlyView.
This study presents a new control strategy for doubly fed induction generator (DFIG) wind turbine systems to overcome the limitations of traditional direct field control using proportional‐integral (DFOC‐PI) regulators, which are sensitive to coefficient changes and lead to low power quality.
Hamza Gasmi, Habib Benbouhenni, Z. M. S. Elbarary, Ilhami Colak, Tahar Tafticht, Salman Arafath Mohammed   +5 more
wiley   +1 more source

Theoretical Model of Transient Regression of Thermoplastic Materials During Flame Spread: Vaporization; Permanent Mass Loss; Surface Shape

Fire and Materials, EarlyView.
ABSTRACT This article examines a transient, one‐dimensional model of surface regression during opposed flow flame spread over finite thickness, non‐charring thermoplastics. Gas to solid conductive transfer from the flame drives sample heating. The solid degrades into volatile fuel molecules in two stages: (1) the pre‐vaporization heat‐up stage and (2 ...
Indrek S. Wichman, Linwei Mou, Sarzina Hossain, Fletcher J. Miller, Sandra L. Olson   +4 more
wiley   +1 more source

Forecasting With Machine Learning Shadow‐Rate VARs

Journal of Forecasting, EarlyView.
ABSTRACT Interest rates are fundamental in macroeconomic modeling. Recent studies integrate the effective lower bound (ELB) into vector autoregressions (VARs). This paper studies shadow‐rate VARs by using interest rates as a latent variable near the ELB to estimate their shadow‐rate values.
Michael Grammatikopoulos
wiley   +1 more source

A highly accurate numerical method for solving boundary value problem of generalized Bagley‐Torvik equation

Mathematical Methods in the Applied Sciences, EarlyView.
A highly accurate numerical method is given for the solution of boundary value problem of generalized Bagley‐Torvik (BgT) equation with Caputo derivative of order 0<β<2$$ 0<\beta <2 $$ by using the collocation‐shooting method (C‐SM). The collocation solution is constructed in the space Sm+1(1)$$ {S}_{m+1}^{(1)} $$ as piecewise polynomials of degree at ...
Suzan Cival Buranay, Mtema James Chin, Nazim I. Mahmudov   +2 more
wiley   +1 more source

Duality for Evolutionary Equations With Applications to Null Controllability

Mathematical Methods in the Applied Sciences, EarlyView.
ABSTRACT We study evolutionary equations in exponentially weighted L2$$ {\mathrm{L}}^2 $$‐spaces as introduced by Picard in 2009. First, for a given evolutionary equation, we explicitly describe the ν$$ \nu $$‐adjoint system, which turns out to describe a system backwards in time. We prove well‐posedness for the ν$$ \nu $$‐adjoint system. We then apply
Andreas Buchinger, Christian Seifert
wiley   +1 more source