Results 81 to 90 of about 1,581,787 (389)

Station-Keeping Maneuver Simulation for the Koreasat Spacecraft Using Mission Analysis Software [PDF]

open access: yesJournal of Astronomy and Space Sciences, 1995
A series of east/west and north/south station-keeping maneuvers were simulated for the KOREASAT spacecraft which has to be maintained within ±0°.05 at the nominal longitude of 116°E. Weekly and biweekly based station-keeping maneuver plannings were used,
Byoung-Sun Lee, Jong Won Eun
doaj  

Heterojunction‐Driven Stochasticity: Bi‐Heterojunction Noise‐Enhanced Negative Transconductance Transistor in Image Generation

open access: yesAdvanced Materials, EarlyView.
This work engineered a bi‐heterojunction noise‐enhanced negative transconductance (BHN‐NTC) transistor using a half‐PTCDI‐C13 layer, achieving expanded and tunable noise characteristics. This advancement enables efficient multi‐bit TRNGs for AI‐driven image generation and enhances logic circuit applications.
Youngmin Han   +6 more
wiley   +1 more source

Biological and Biologically Inspired Functional Nanostructures: Insights into Structural, Optical, Thermal, and Sensing Applications

open access: yesAdvanced Materials, EarlyView.
Biological and biologically‐inspired functional nanostructures with structural, thermal, optical, and sensing applications are reviewed. The role of nanoscale features in biological materials on performance is described, and their blueprints are used for bio‐inspired nanomaterials, synthesized using advanced techniques (i.e., photolithography, bio ...
Chao Hsuan (Joseph) Sung   +15 more
wiley   +1 more source

Tracking systems for satellite communications

open access: yesIEE Proceedings F Communications, Radar and Signal Processing, 1988
Satellites in nominally geostationary orbits possess diurnal motion which causes the apparent position of the spacecraft to wander in the sky as seen by an earth station. If uncompensated this causes a variation in the performance of the communications link. The motion of the satellite therefore has to be tracked by the earth station antenna.
Hawkins, GJ, Edwards, DJ, McGeehan, JP
openaire   +4 more sources

Direct Integration of Polycrystalline Diamond With 3C‐SiC for Enhanced Thermal Management in GaN HEMTs: Impact of Grain Structure and Interface Engineering

open access: yesAdvanced Materials Technologies, EarlyView.
Polycrystalline diamond (PCD) is directly bonded to 3C‐SiC for GaN HEMTs on a 2‐inch wafer using an advanced room‐temperature process. Despite high thermal conductivity at the growth surface, phonon scattering at the fine‐grained nucleation side raises thermal resistance.
Chiharu Moriyama   +7 more
wiley   +1 more source

Cross-polarisation discrimination-induced interference in dual-polarised high-capacity satellite communication systems

open access: yesThe Journal of Engineering, 2016
The design of spectrally-efficient, high-throughput satellite (HTS) systems with capacity approaching one terabit per second requires operating at Ka-band frequencies and above, where there are several gigahertz of allocated radio spectrum, using ...
Abdulkareem Sarki Karasuwa   +2 more
doaj   +1 more source

A generalized transmultiplexer and its application to mobile satellite communications [PDF]

open access: yes
A generalization of digital transmultiplexer technology is presented. The proposed method can realize transmultiplexer (TMUX) and transdemultiplexer (TDUX) filter banks whose element filters have bandwidths greater than the channel spacing frequency ...
Ichiyoshi, Osamu
core   +1 more source

Synergistic EMI Shielding: The Role of Nanoparticle Size and Alternating Bi‐Layer Coatings in Hybrid Fabrics

open access: yesAdvanced Materials Technologies, EarlyView.
This study fabricates three types of hybrid knitted fabrics: AgNPs of varying sizes are synthesized on the fabric, MXene nanosheets are applied via spray coating, and alternating AgNPs/MXene bi‐layers are added. The effects of particle size, material type, and bi‐layer structure on EMI shielding (≈60 dB), as well as breathability, air permeability, and
Hamed Mohammadi Mofarah   +5 more
wiley   +1 more source

Access and mobility management technologies for 6G satellite communications network

open access: yesDianxin kexue, 2021
Analsisand outlook for satellite communication access and mobility management technology in 6G network was presented.Firstly, the access technology of current global representative satellite mobile communications system was introduced, as well as the ...
Xiaowen WU   +5 more
doaj   +2 more sources

Enhancing Reptile search algorithm with shifted distribution estimation strategy for coverage optimization in wireless sensor networks

open access: yesHeliyon
The rapid development of the Internet of Things (IoT) has extensively promoted the development of Wireless Sensor Networks (WSNs), an essential technology for series displaying perception and data collected from the physical world. In densely distributed
Na Ma, Shouxin Wang, Shuailing Hao
doaj   +1 more source

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