Results 31 to 40 of about 56,614 (262)

System engineering approach applied to Galileo system [PDF]

, 2010
Developing a localization system, with more precise performances than GPS that guarantees Europe autonomy is a complex challenge that ESA and a large number of European economical actors of space industry were decided to meet.
Bouchired, Steven, Lizy-Destrez, Stéphanie   +1 more
core   +1 more source

Low-Orbit Large-Scale Communication Satellite Constellation Configuration Performance Assessment

International Journal of Aerospace Engineering, 2022
A constellation configuration performance evaluation method is proposed for the performance evaluation of the low-orbit large-scale communication satellite constellations.
Tianyu Sun, Min Hu, Chaoming Yun
doaj   +1 more source

Optimization of multiple access mode for large-scale constellation networking communication

Xibei Gongye Daxue Xuebao, 2023
In the large-scale satellite constellation technology, the establishment of satellite internal network is the top priority. As the network capacity of the constellation continues to expand and the number of satellite nodes continues to increase, the ...
GUO Xiaoxu, XU Zhaobin, XU Kedi, ZHU Yaowei, JIN Zhonghe   +4 more
doaj   +1 more source

Generic Approach for Hierarchical Modulation Performance Analysis: Application to DVB-SH [PDF]

, 2011
Broadcasting systems have to deal with channel diversity in order to offer the best rate to the users. Hierarchical modulation is a practical solution to provide several rates in function of the channel quality.
Amiot-Bazile, Caroline, Arnal, Fabrice, Boucheret, Marie-Laure, Lacan, Jérôme, Méric, Hugo   +4 more
core   +4 more sources

Capacity Density Assessment of Satellite Constellation Network

天地一体化信息网络, 2023
The traditional analytical method greatly underestimates the throughput capability of the system in low beam density scenario, and cannot reveal the capacity saturation phenomenon in high beam density scenario.To overcome the preceding problems, a new ...
Xian MENG, Dali QIN, Yu WANG, Chuili KONG, Hejia LUO, Jun WANG   +5 more
doaj   +2 more sources

RIPK4 function interferes with melanoma cell adhesion and metastasis

Molecular Oncology, EarlyView.
RIPK4 promotes melanoma growth and spread. RIPK4 levels increase as skin lesions progress to melanoma. CRISPR/Cas9‐mediated deletion of RIPK4 causes melanoma cells to form less compact spheroids, reduces their migratory and invasive abilities and limits tumour growth and dissemination in mouse models.
Norbert Wronski, Sławomir Lasota, Ewelina Madej, Anna A. Brożyna, Małgorzata Szczygieł, Agnieszka Harazin‐Lechowska, Jan Czerbniak, Janusz Rys, Jaroslaw Czyz, Agnieszka Wolnicka‐Glubisz   +9 more
wiley   +1 more source

Designing good partial coverage satellite constellations

Astrodynamics Conference, 1990
Design of satellite constellations providing partial coverage of certain ground regions is becoming more important as small low-altitude satellites receive increased attention. The purpose of this study is to develop the procedures necessary for deriving the best constellations for partial coverage.
Hanson, John, Evans, Maria, Turner, Ronald   +2 more
openaire   +3 more sources

Bistable Mechanisms 3D Printing for Mechanically Programmable Vibration Control

Advanced Engineering Materials, EarlyView.
This work introduces a 3D‐printed bistable mechanism integrated into tuned mass dampers (TMDs) for mechanically adaptive passive vibration suppression. Through optimized geometry, the bistable design provides adaptable vibration reduction across a broad range of scenarios, achieving effective vibration mitigation without complex controls or external ...
Ali Zolfagharian, Frédéric Demoly, Mohammad Lakhi, Bernard Rolfe, Mahdi Bodaghi   +4 more
wiley   +1 more source

Suppression of co-channel interference in NGSO constellation system with interference alignment

Tongxin xuebao, 2021
Aiming at the problem that in the current space， non-geostationary satellite orbit （NGSO） constellation systems were increasing day by day， there are more and more satellite networks nearby orbiting using the same frequency band， and the problem of co ...
Bing DU, Jiawang LI, Xianmei WANG, Wei LI, Xiangnan LIU, Haijun ZHANG   +5 more
doaj   +2 more sources

Electrical Conductivities of Conductors, Semiconductors, and Their Mixtures at Elevated Temperatures

Advanced Engineering Materials, EarlyView.
This article presents a comprehensive review of temperature‐dependent electrical conductivity data for multiple material classes at elevated temperatures, highlighting a persistent conductivity gap between metals and semiconductors in the range of 102$\left(10\right)^{2}$– 107$\left(10\right)^{7}$ S/m. Metal–ceramic irregular metamaterials are proposed
Valentina Torres Nieto, Marcia A. Cooper
wiley   +1 more source