Results 141 to 150 of about 153,055 (297)

Quantitative Diffusion and T2 Mapping Using RF‐Modulated Phase‐Based Gradient Echo Imaging

open access: yesMagnetic Resonance in Medicine, EarlyView.
ABSTRACT Purpose To introduce and evaluate the feasibility of a novel RF‐phase modulated gradient echo (GRE) method for quantitative diffusion MRI, aimed at mitigating geometric distortion and enabling high‐resolution 3D quantitative diffusion/T2 mapping as a complementary alternative to conventional DWI.
Daiki Tamada   +4 more
wiley   +1 more source

Optimizing Selective RF Pulses for Enhanced Signal Stability in Turbo Spin Echo Using a Differentiable Extended Phase Graph Model

open access: yesMagnetic Resonance in Medicine, EarlyView.
ABSTRACT Purpose To improve slice profile consistency across echo trains in turbo spin echo (TSE) imaging, thereby reducing image blurring and increasing the accuracy of multi echo spin echo T2$$ {T}_2 $$ mapping. Methods Excitation and refocusing RF pulses were optimized for TSE using a differentiable extended phase graph model that incorporates the ...
Madison M. Augelli   +3 more
wiley   +1 more source

An Exact Method for Reliable Shortest Path Problems With Correlation

open access: yesNetworks, EarlyView.
ABSTRACT Shortest path problems often arise in contexts where travel times are uncertain. In these settings, reliable paths are often valued more than paths with lower expected travel times. This has led to several variants of reliable shortest path problems (RSPP) that handle travel time reliability differently. We propose an algorithmic framework for
Esteban Leiva   +3 more
wiley   +1 more source

Back to the Mission. Revisiting Slack in Nonprofits and Introducing Tappable Slack

open access: yesNonprofit Management and Leadership, EarlyView.
ABSTRACT This article contributes to and develops the previous literature on excess resources (“slack”) in nonprofit organizations through a conceptual analysis of the implications that the organizational distinctiveness of nonprofits carries for our understanding of slack in these organizations.
Marta Reuter   +2 more
wiley   +1 more source

All‐sky assimilation impacts of the Tomorrow.io microwave sounder constellation on global weather forecasts

open access: yesQuarterly Journal of the Royal Meteorological Society, EarlyView.
Key Findings: An assimilation methodology is established for the Tomorrow.io microwave sounder (TMS) flying on CubeSats in sun‐synchronous and inclined orbits, and in all cloud scenes. The TMS has a significant impact on weather forecast lead times up to 3 days in the Tropics in a research‐quality numerical weather prediction setting, and yields water ...
Jonathan J. Guerrette   +3 more
wiley   +1 more source

Adaptive CUSUM Chart for Simultaneous Monitoring of Mean and Variance

open access: yesQuality and Reliability Engineering International, EarlyView.
ABSTRACT Simultaneously monitoring changes in both the mean and variance is a fundamental problem in statistical process control, and numerous methods have been developed to address it. However, many existing approaches face notable limitations: Some rely on tuning parameters that can significantly affect performance; others are biased toward detecting
Gokul Parakulum, Jun Li
wiley   +1 more source

Optimal Gain Selection for the Arbitrary‐Order Homogeneous Differentiator

open access: yesInternational Journal of Robust and Nonlinear Control, EarlyView.
ABSTRACT Differentiation of noisy signals is a relevant and challenging task. Widespread approaches are the linear high‐gain observer acting as a differentiator and Levant's robust exact differentiator with a discontinuous right‐hand side. We consider the family of arbitrary‐order homogeneous differentiators, which includes these special cases.
Benjamin Calmbach   +2 more
wiley   +1 more source

Periodic Scenario Trees: A Novel Framework for Robust Periodic Invariance and Stabilization of Constrained Uncertain Linear Systems

open access: yesInternational Journal of Robust and Nonlinear Control, EarlyView.
ABSTRACT This work proposes a new framework for stabilizing uncertain linear systems and for determining robust periodic invariant sets and their associated control laws for constrained uncertain linear systems. Necessary and sufficient conditions for stabilizability by periodic controllers are stated and proven using finite step Lyapunov functions for
Yehia Abdelsalam   +2 more
wiley   +1 more source

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

open access: yesInternational 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

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