Results 21 to 30 of about 34,814 (161)

The Evolution of Autonomous Systems for Planetary Cave Exploration: A Review

open access: yesJournal of Field Robotics, EarlyView.
ABSTRACT The exploration of Subsurface Access Points (SAPs), such as lava tubes on the Moon and Mars, has gained significant interest due to their potential as stable environments shielded from surface radiation and temperature extremes. These sites are considered high‐value targets for detecting water and signs of ancient life, and assessing their ...
Sarah Swinton   +4 more
wiley   +1 more source

Mobile remote manipulator system for a tetrahedral truss [PDF]

open access: yes, 1988
The mobile remote manipulator system (MRMS) was initially developed for transit about the trusses of the delta space station; however, it can be utilized just as easily for transit about the trusses of the dual keel station.
Schneider, William C.   +1 more
core   +1 more source

Wall‐to‐wall Amazon forest height mapping with Planet NICFI, Aerial LiDAR, and a U‐Net regression model

open access: yesRemote Sensing in Ecology and Conservation, EarlyView.
Tree canopy height is a key indicator of forest biomass and structure, yet accurate mapping across the Amazon remains challenging. Here, we generated a canopy height map of the Amazon forest at ~4.8 m resolution using Planet NICFI imagery and a deep learning U‐Net model trained with airborne LiDAR data.
Fabien H. Wagner   +21 more
wiley   +1 more source

Scale dependence in remotely sensed biodiversity: Leveraging continental‐scale imaging spectroscopy from the National Ecological Observatory Network

open access: yesRemote Sensing in Ecology and Conservation, EarlyView.
Imaging spectroscopy enables large‐scale biodiversity assessment, yet spectral diversity metrics are scale dependent. Across 15 NEON ecosystems, we find that spectral richness increases sub‐linearly from 3600 m2 to 4 km2, whereas spectral divergence shows weak or inconsistent scaling with area, underscoring the importance of scale‐aware interpretation ...
Meghan T. Hayden   +8 more
wiley   +1 more source

On Reflection of Shock Waves from Boundary Layers [PDF]

open access: yes, 1952
Measurements of the reflection characteristics of shock waves from a flat surface with a laminar and turbulent boundary layer are presented. The investigations were carried out at Mach numbers from about 1.3 to 1.5 and a Reynolds number of 0.9 x 10^4.
Dhawan, S., Liepmann, H. W., Roshko, A.
core   +1 more source

Tracing Three Decades of Low Earth Orbit Satellite Communication Development: A Bibliometric and Main Path Analysis of Network Architectures, Protocol Evolution, and Emerging Intelligent Services

open access: yesInternational Journal of Satellite Communications and Networking, EarlyView.
ABSTRACT Low Earth Orbit (LEO) satellite communication systems have evolved into a critical component of global broadband networks, enabling wide‐area connectivity, IoT services, and intelligent multilayer satellite–terrestrial integration. Despite rapid advancements in constellation deployment, routing mechanisms, resource management, and LEO–5G/6G ...
Wei‐Hao Su   +2 more
wiley   +1 more source

Directive Antenna Clutter Loss in Slant Paths

open access: yesInternational Journal of Satellite Communications and Networking, EarlyView.
ABSTRACT This paper investigates the development of a clutter loss model specifically for slant paths involving directive antennas. Conventionally, clutter loss is characterized by using isotropic antennas to facilitate standard link budget calculations via single antenna gain values.
Fernando Pérez Fontán   +4 more
wiley   +1 more source

Effect of Postweld Heat Treatment on Laser‐Welded Duplex Stainless Steel: Crystallographic Patterns and Fatigue Behavior

open access: yessteel research international, EarlyView.
Laser welding of duplex stainless steel disrupts phase balance, promotes nitride precipitation, and reduces fatigue resistance. Postweld heat treatment restores austenite and dissolves nitrides, but the resulting crystallography and phase morphology still impair fatigue performance.
Aparecida Silva Magalhães   +6 more
wiley   +1 more source

Woven Eutectic Lamellar Structures Lead to Ultrahigh Strength and Energy Absorption Capacity in Additively Manufactured Lattice Structures

open access: yesSmall Structures, Volume 6, Issue 5, May 2025.
Herein, AlCoCrFeNi2.1 is selected to produce lattice structures by selective laser melting. The as‐printed lattice structures consist of numerous colonies of nanosized eutectic lamellar structures which are bent and interwind with each other to form a woven microstructure. The unique microstructure leads to unprecedented effective metal strength, yield
Zhiyong Ji   +6 more
wiley   +1 more source

Apex predators exploit advantageous snow conditions across hunting modes

open access: yesJournal of Animal Ecology, EarlyView.
Advantageous snow conditions—in terms of snow depth and density—are among the most important features of the winter landscape for two apex predators, regardless of hunting strategy. In a warming climate, the knock‐on effects of a diminishing snowpack may reduce the hunting success of multiple large carnivore species.
Benjamin K. Sullender   +7 more
wiley   +1 more source

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