Results 31 to 40 of about 30,459 (234)

Resource reallocation across successive systemic innovations: How Rolls‐Royce shaped the evolution of the turbojet, turboprop, and turbofan

open access: yesStrategic Management Journal, EarlyView.
Abstract Research Summary Despite the importance of resource reallocation in shaping a variety of strategic outcomes, strategy scholars have paid only limited attention to the processes by which firms reallocate their resources across successive systemic innovations.
Gino Cattani   +2 more
wiley   +1 more source

Feature Extraction Method of Helicopter Target Based on Flicker Phenomenon Combined With Phase Compensation

open access: yesIEEE Access, 2022
For the typical multi-component periodic micro-Doppler signal parameter estimation, a helicopter rotor feature extraction method based on flicker phenomenon and phase compensation is proposed in this paper.
Saiqiang Xia   +6 more
doaj   +1 more source

Computational fluid dynamics model of a quad-rotor helicopter for dynamic analysis [PDF]

open access: yes, 2016
The control and performance of a quad-rotor helicopter UAV is greatly influenced by its aerodynamics, which in turn is affected by the interactions with features in its remote environment. This paper presents details of Computational Fluid Dynamics (CFD)
Bousbaine, Amar   +2 more
core   +2 more sources

Monitoring wildlife using long‐endurance solar‐electric UAVs

open access: yesWildlife Biology, EarlyView.
This report discusses the effectiveness of using small solar‐electric UAV (uncrewed aerial vehicles) for aerial wildlife monitoring. We review four years of aerial wildlife monitoring missions using a 5.5‐m wingspan, solar‐electric UAV that was equipped with a gimballed IR/RGB camera.
Götz Bramesfeld   +3 more
wiley   +1 more source

Manoeuvrability assessment of a hybrid compound helicopter configuration [PDF]

open access: yes, 2014
The compound helicopter design could potentially satisfy the new emerging requirements placed on the next generation of rotorcraft. The main benefit of the compound helicopter is its ability to reach speeds that significantly surpass the conventional ...
Ferguson, Kevin, Thomson, Douglas
core  

Using unmanned aerial vehicles (drones) to improve access to blood in low‐ and middle‐income countries: Current challenges and opportunities

open access: yesVox Sanguinis, EarlyView.
Abstract Blood transfusion is life‐saving for patients in emergencies, but low‐ and middle‐income countries (LMICs) often face a severe shortage of banked blood. Establishing blood banks in rural areas presents substantial logistical and economic challenges for many LMICs.
Suvro Sankha Datta   +4 more
wiley   +1 more source

MODELING, CONTROL AND NAVIGATION OF AN AUTONOMOUS QUAD-ROTOR HELICOPTER [PDF]

open access: yesInterdisciplinary Description of Complex Systems, 2016
Autonomous outdoor quad-rotor helicopters increasingly attract the attention of potential researchers. Several structures and configurations have been developed to allow 3D movements.
Damir Šoštarić
doaj   +1 more source

Signal Enhancement of Helicopter Rotor Aerodynamic Noise Based on Cyclic Wiener Filtering

open access: yesApplied Sciences, 2022
The research on helicopter rotor aerodynamic noise becomes imperative with the wide use of helicopters in civilian fields. In this study, a signal enhancement method based on cyclic Wiener filtering was proposed given the cyclostationarity of rotor ...
Chengfeng Wu   +3 more
doaj   +1 more source

Coupled flight dynamics and CFD - demonstration for helicopters in shipborne environment [PDF]

open access: yes, 2017
The development of high-performance computing and computational fluid dynamics methods have evolved to the point where it is possible to simulate complete helicopter configurations with good accuracy.
Barakos, G.N., Crozon, C., Steijl, R.
core   +1 more source

Design Challenges to Expand the Functionality of Drones: Deformable Rotorcraft and Nature‐Inspired Flapping Drones

open access: yesAdvanced Intelligent Systems, Volume 8, Issue 3, March 2026.
This review systematically analyzes deformable drones, including extendable, foldable, and tilting configurations, along with nature‐inspired flapping rotorcraft. By classifying deformation principles and structural mechanisms, design trade‐offs, functional capabilities, and future development potential are highlighted.
Ju‐Hee Lee   +9 more
wiley   +1 more source

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