Results 61 to 70 of about 2,364,396 (151)

Two Two‐Tier Stochastic Frontier Replications

Journal of Applied Econometrics, EarlyView.
ABSTRACT We replicate the two foundational studies which proposed the two‐tier stochastic frontier model, first in the cross‐sectional setting and then for the fixed effects panel data model. We explore matters of software then and now, different mathematical formulations of the likelihood, and alternative current software tools.
Alecos Papadopoulos, Christopher Parmeter   +1 more
wiley   +1 more source

Image Noise Reduction and Solution of Unconstrained Minimization Problems via New Conjugate Gradient Methods

Mathematics
The conjugate gradient (CG) directions are among the important components of the CG algorithms. These directions have proven their effectiveness in many applications—more specifically, in image processing due to their low memory requirements.
Bassim A. Hassan, Issam A. R. Moghrabi, Thaair A. Ameen, Ranen M. Sulaiman, Ibrahim Mohammed Sulaiman   +4 more
doaj   +1 more source

Weakly Convex Ridge Regularization for 3D Non‐Cartesian MRI Reconstruction

Magnetic Resonance in Medicine, EarlyView.
ABSTRACT Purpose While highly accelerated non‐Cartesian acquisition protocols significantly reduce scan time, they often entail long reconstruction delays for 3D data. Deep learning–based reconstruction methods can alleviate this, but typically rely on complex, highly parametrized architectures.
German Shâma Wache, Chaithya G R, Asma Tanabene, Sebastian Neumayer   +3 more
wiley   +1 more source

Efficient digital quadratic unconstrained binary optimization solvers for SAT problems

New Journal of Physics
Boolean satisfiability (SAT) is a propositional logic problem of determining whether an assignment of variables satisfies a Boolean formula. Many combinatorial optimization problems can be formulated in Boolean SAT logic—either as k -SAT decision ...
Robert Simon Fong, Yanming Song, Alexander Yosifov   +2 more
doaj   +1 more source

Left-deep join order selection with higher-order unconstrained binary optimization on quantum computers

Frontiers in Computer Science
Join order optimization is among the most crucial query optimization problems, and its central position is also evident in the new research field where quantum computing is applied to database optimization and data management.
Valter Uotila
doaj   +1 more source

Quadratic and nonlinear programming problems solving and analysis in fully fuzzy environment

Alexandria Engineering Journal, 2015
This paper presents a comprehensive methodology for solving and analyzing quadratic and nonlinear programming problems in fully fuzzy environment. The solution approach is based on the Arithmetic Fuzzy Logic-based Representations, previously founded on ...
Walaa Ibrahim Gabr
doaj   +1 more source

A Gauss–Newton Method for ODE Optimal Tracking Control

Optimal Control Applications and Methods, EarlyView.
This paper presents a Gauss–Newton method for optimal tracking control of ordinary differential equations (ODEs). The approach formulates the problem as an infinite‐dimensional optimization problem, allowing both control functions and uncertain model parameters to be optimized.
Vicky Holfeld, Michael Burger, Claudia Schillings   +2 more
wiley   +1 more source

Friction‐Aware Force‐Realizable Safety Control for Four‐Wheel Independently Steered and Driven Mobile Robots

International Journal of Robust and Nonlinear Control, EarlyView.
ABSTRACT Safety‐critical control remains a major challenge for four‐wheel independently steered and driven (4ISD) mobile robots, where high‐accuracy path tracking and obstacle avoidance must be achieved under over‐actuated steering–driving coordination, tire–ground friction limits, and wheel‐torque constraints.
Ruitong Liu, Kenji Hashimoto
wiley   +1 more source

Multi-Objective Portfolio Optimization Using a Quantum Annealer

Mathematics
In this study, the portfolio optimization problem is explored, using a combination of classical and quantum computing techniques. The portfolio optimization problem with specific objectives or constraints is often a quadratic optimization problem, due to
Esteban Aguilera, Jins de Jong, Frank Phillipson, Skander Taamallah, Mischa Vos   +4 more
doaj   +1 more source

The role of identification in data‐driven policy iteration: A system theoretic study

International Journal of Robust and Nonlinear Control, EarlyView.
Abstract The goal of this article is to study fundamental mechanisms behind so‐called indirect and direct data‐driven control for unknown systems. Specifically, we consider policy iteration applied to the linear quadratic regulator problem. Two iterative procedures, where data collected from the system are repeatedly used to compute new estimates of ...
Bowen Song, Andrea Iannelli
wiley   +1 more source