TOWARDS AN IMPROVED V-VLC OPTICAL CHANNEL MODELLING

2021 ◽  
Author(s):  
Guillaume Mario Dotreppe ◽  
Jan Coosemans ◽  
Valéry Ann Jacobs

Visible Light Communication (VLC) requires better optical channel modelling if it is to be used in vehicular applications. Therefore, the radiation transfer between the transmitter and emitter shall be well defined in all circumstances. An important aspect herein is the determination of the Limiting Photometric Distance (LPD), which characterises the transition between near-field and far-field description of the light source. The LPD allows to determine whether simplified equations can be used in the V-VLC channel model. A first step towards this goal is the analysis of a simple, narrow beam, disk-source with uniform luminance. On-axis, analytical solutions exist. Off-axis, however, no closed loop solutions exist. Therefore, a numerical approach is used, which is validated against on-axis measurements and then expanded to off-axis scenarios. This allows to compute the on- and off-axis LPD of the light source, an important step towards a more accurate description of complex systems for VLC.

1997 ◽  
Vol 36 (04/05) ◽  
pp. 237-240
Author(s):  
P. Hammer ◽  
D. Litvack ◽  
J. P. Saul

Abstract:A computer model of cardiovascular control has been developed based on the response characteristics of cardiovascular control components derived from experiments in animals and humans. Results from the model were compared to those obtained experimentally in humans, and the similarities and differences were used to identify both the strengths and inadequacies of the concepts used to form the model. Findings were confirmatory of some concepts but contrary to some which are firmly held in the literature, indicating that understanding the complexity of cardiovascular control probably requires a combination of experiments and computer models which integrate multiple systems and allow for determination of sufficiency and necessity.


2012 ◽  
Vol E95-B (1) ◽  
pp. 254-262
Author(s):  
Yoshitoshi YAMASHITA ◽  
Eiji OKAMOTO ◽  
Yasunori IWANAMI ◽  
Yozo SHOJI ◽  
Morio TOYOSHIMA ◽  
...  

2021 ◽  
Author(s):  
Bayu Prastowo ◽  
Renan Prasta Jenie ◽  
Ichsan Hardyanto ◽  
Muhammad Dahrul ◽  
Johan Iskandar ◽  
...  
Keyword(s):  

1989 ◽  
Vol 20 (5) ◽  
pp. 205-217
Author(s):  
J Deforges ◽  
P Garcia ◽  
J Bastie ◽  
F Marandet ◽  
J Bernard ◽  
...  

2015 ◽  
Vol 7 (3-4) ◽  
pp. 369-377 ◽  
Author(s):  
Alex Pacini ◽  
Alessandra Costanzo ◽  
Diego Masotti

An increasing interest is arising in developing miniaturized antennas in the microwave range. However, even when the adopted antennas dimensions are small compared with the wavelength, radiation performances have to be preserved to keep the system-operating conditions. For this purpose, magneto-dielectric materials are currently exploited as promising substrates, which allows us to reduce antenna dimensions by exploiting both relative permittivity and permeability. In this paper, we address generic antennas in resonant conditions and we develop a general theoretical approach, not based on simplified equivalent models, to establish topologies most suitable for exploiting high permeability and/or high-permittivity substrates, for miniaturization purposes. A novel definition of the region pertaining to the antenna near-field and of the associated field strength is proposed. It is then showed that radiation efficiency and bandwidth can be preserved only by a selected combinations of antenna topologies and substrate characteristics. Indeed, by the proposed independent approach, we confirm that non-dispersive magneto-dielectric materials with relative permeability greater than unit, can be efficiently adopted only by antennas that are mainly represented by equivalent magnetic sources. Conversely, if equivalent electric sources are involved, the antenna performances are significantly degraded. The theoretical results are validated by full-wave numerical simulations of reference topologies.


2021 ◽  
Vol 29 ◽  
pp. 100339
Author(s):  
Farah Mahdi Alsalami ◽  
Zahir Ahmad ◽  
Stanislav Zvanovec ◽  
Paul Anthony Haigh ◽  
Olivier C.L. Haas ◽  
...  

1999 ◽  
Author(s):  
Soenke Seebacher ◽  
Wolfgang Osten ◽  
Werner P. O. Jueptner ◽  
Vadim P. Veiko ◽  
Nikolay B. Voznesensky

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