Results 131 to 140 of about 2,103,194 (320)
A Quiet Helicopter for Air Taxi Operations [PDF]
NASA is exploring rotorcraft designs for VTOL air taxi operations, also known as urban air mobility (UAM) or on-demand mobility (ODM) applications. Several concept vehicles have been developed, intended to focus and guide NASA research activities in ...
Johnson, Wayne
core +1 more source
Sources, control, and effects of noise from aircraft propellers and rotors [PDF]
, 1981 Source noise predictions are compared with measurements for conventional low-speed propellers, for new high speed propellers (propfans), and for a helicopter.
Dempsey, T. K. +2 more
core +2 more sources
International Journal of Robust and Nonlinear Control, EarlyView.ABSTRACT This paper develops a framework for designing output feedback controllers for constrained linear parameter‐varying systems that experience persistent disturbances. We specifically propose an incremental parameter‐varying output feedback control law to address control rate constraints, as well as state and control amplitude constraints.
Jackson G. Ernesto +2 more
wiley +1 more source
Implications of future atmospheric composition in decision-making for sustainable aviation
Environmental Research Letters, 2021 Irene C Dedoussi
doaj +1 more source
Design and test of aircraft engine isolators for reduced interior noise [PDF]
Improved engine vibration isolation was proposed to be the most weight and cost efficient retrofit structure-borne noise control measure for single engine general aviation aircraft.
Scheidt, D. C., Unruh, J. F.
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PID‐Like Robust Control of Non‐Minimum Phase Robotic Manipulators
International Journal of Robust and Nonlinear Control, EarlyView.ABSTRACT This paper proposes an output‐feedback tracking controller for non‐minimum phase nonlinear systems with unknown uncertainties and external disturbances, where not all states are measurable, and the zero dynamics are unstable. The approach combines a backstepping‐based stabilizing state‐feedback law with a cascade extended high‐gain observer ...
Mohammad Al Saaideh +2 more
wiley +1 more source
New developments in blown flap noise technology [PDF]
The noise technology relating to blown-flap systems is reviewed. There are three general sources of noise: turbomachinery, airframe, and the interaction noise of the jet blowing on the flaps.
Gibson, J. S.
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Deep Reinforcement Learning‐Based Control for Real‐Time Hybrid Simulation of Civil Structures
International Journal of Robust and Nonlinear Control, EarlyView.ABSTRACT Real‐time Hybrid Simulation (RTHS) is a cyber‐physical technique that studies the dynamic behavior of a system by combining physical and numerical components that are coupled through a boundary condition enforcer. In structural engineering, the numerical components are subjected to environmental loads that become dynamic displacements of the ...
Andrés Felipe Niño +6 more
wiley +1 more source
Effect of cessation of late-night landing noise on sleep electrophysiology in the home [PDF]
Simultaneous measurements of noise exposure and sleep electrophysiology were made in homes before and after cessation of nighttime aircraft landing noise.
Bennett, R. L. +4 more
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Software to Support Remote Sensing of River Discharge Based on Critical Flow Theory
River Research and Applications, EarlyView.ABSTRACT Water resource management requires accurate observations of streamflow but standard field methods for measuring river discharge (Q$$ Q $$) can be costly and hazardous for equipment and personnel. Remote sensing has become a viable alternative, but many image‐based techniques require field data for calibration, and depth and velocity can seldom
Carl J. Legleiter, Inhyeok Bae
wiley +1 more source