Estimation Of The Effect Of Dispersion On The Communication Range In A Wireless Underwater Optical Channel

Author(s):  
N. E. Miroshnikova ◽  
G. S. Petruchin ◽  
P. A. Titovec
2012 ◽  
Vol E95-B (1) ◽  
pp. 254-262
Author(s):  
Yoshitoshi YAMASHITA ◽  
Eiji OKAMOTO ◽  
Yasunori IWANAMI ◽  
Yozo SHOJI ◽  
Morio TOYOSHIMA ◽  
...  

2003 ◽  
Author(s):  
Temel Bilici ◽  
Senol Isci ◽  
Adnan Kurt ◽  
Ali Serpenguzel
Keyword(s):  

Robotica ◽  
2021 ◽  
pp. 1-17
Author(s):  
Ali Moltajaei Farid ◽  
Md Abdus Samad Kamal ◽  
Simon Egerton

SUMMARY This paper proposes and evaluates swarming mechanisms of patrolling unmanned aerial vehicles (UAVs) that can collectively search a region for intruding UAVs. The main contributions include the development of multi-objective searching strategies and investigation of the required sensor configurations for the patrolling UAVs. Numerical results reveal that it is sometimes better to search through a region with a single swarm rather than multiple swarms deployed over sub-regions. Moreover, a large communication range does not necessarily improve search performances, and the patrolling swarm must have a speed close to the speed of the intruding UAVs to maximize the search performances.


Sensors ◽  
2021 ◽  
Vol 21 (9) ◽  
pp. 2956
Author(s):  
Hojin Kang Kim ◽  
Raimundo Becerra ◽  
Sandy Bolufé ◽  
Cesar A. Azurdia-Meza ◽  
Samuel Montejo-Sánchez ◽  
...  

The opportunistic exchange of information between vehicles can significantly contribute to reducing the occurrence of accidents and mitigating their damages. However, in urban environments, especially at intersection scenarios, obstacles such as buildings and walls block the line of sight between the transmitter and receiver, reducing the vehicular communication range and thus harming the performance of road safety applications. Furthermore, the sizes of the surrounding vehicles and weather conditions may affect the communication. This makes communications in urban V2V communication scenarios extremely difficult. Since the late notification of vehicles or incidents can lead to the loss of human lives, this paper focuses on improving urban vehicle-to-vehicle (V2V) communications at intersections by using a transmission scheme able of adapting to the surrounding environment. Therefore, we proposed a neuroevolution of augmenting topologies-based adaptive beamforming scheme to control the radiation pattern of an antenna array and thus mitigate the effects generated by shadowing in urban V2V communication at intersection scenarios. This work considered the IEEE 802.11p standard for the physical layer of the vehicular communication link. The results show that our proposal outperformed the isotropic antenna in terms of the communication range and response time, as well as other traditional machine learning approaches, such as genetic algorithms and mutation strategy-based particle swarm optimization.


2016 ◽  
Vol 2016 ◽  
pp. 1-13 ◽  
Author(s):  
Wen-Zheng Wang ◽  
Yan-Ming Wang ◽  
Guo-Qing Shi

Respirable coal particle generated during underground mining is the main cause for gas-dust explosions and coal workers’ pneumoconiosis (CWP) which needs accurate monitoring especially on its concentration. Focusing on the coal dust pollution in the fully mechanized working face of Huangbaici coalmine, coal particle was sampled for further industrial analysis and FT-IR test to obtain its chemical composition and optical constant. Combined with the simulated spatial distribution of airborne dust, the spectral transmission characteristics of coal dust within wavelengths of 2.5 to 25 μm under different operating conditions were obtained. The simulation results show that the transmittance and aerosol optical depth (AOD) of coal dust are closely linked and obviously influenced by the variation of dust generation source (intensity of dust release, position of coal cutting, and the wetting of the coal seam) and airflow field (wind speed and direction of ventilation). Furthermore, an optical channel of 1260–1280 cm−1(7.937–7.813 μm) which is almost only sensitive to the variation of dust concentration but dull to the diameter change of coal dust was selected to establish the correlation of dust concentration and infrared transmittance. The fitting curve was then applied to retrieve the equivalent dust concentration based on optical information, and the comparison results demonstrate that the estimated pollution level is consistent with field measurement data in engineering practice.


Sign in / Sign up

Export Citation Format

Share Document