scholarly journals On instantaneous propagation of low-frequency signals in short transmission lines

2021 ◽  
Author(s):  
Steffen Kühn
Keyword(s):  
Basic Principle ◽  
Transmission Lines ◽  
Information Transfer ◽  
Low Frequency ◽  
Speed Of Light ◽  
Low Bit Rate ◽  
Remote Locations ◽  
Transmission Process ◽  
Basic Assumptions ◽  
Voice Message

One of the basic assumptions of physics is that information cannot be transferred more rapidly than light. If one equates information with data, then information transfer is a process in which data are transmitted between two remote locations. According to this basic principle, the transmission process should require an appropriate amount of time so that the distance between these locations divided by the needed time does not exceed the speed of light in a vacuum. However, it is technologically feasible to transmit a voice message, music, or any bit sequence at a low bit rate between locations separated by hundreds of meters, with almost no loss of time. Herein, we demonstrate that this behavior most likely does not contradict special relativity, and we explain this phenomenon based on a model of a superconducting cable.

scholarly journals On instantaneous propagation of low-frequency signals in short transmission lines

2021 ◽  
Author(s):  
Steffen Kühn
Keyword(s):  
Basic Principle ◽  
Transmission Lines ◽  
Information Transfer ◽  
Low Frequency ◽  
Speed Of Light ◽  
Low Bit Rate ◽  
Remote Locations ◽  
Transmission Process ◽  
Basic Assumptions ◽  
Voice Message

One of the basic assumptions of physics is that information cannot be transferred more rapidly than light. If one equates information with data, then information transfer is a process in which data are transmitted between two remote locations. According to this basic principle, the transmission process should require an appropriate amount of time so that the distance between these locations divided by the needed time does not exceed the speed of light in a vacuum. However, it is technologically feasible to transmit a voice message, music, or any bit sequence at a low bit rate between locations separated by hundreds of meters, with almost no loss of time. Herein, we demonstrate that this behavior most likely does not contradict special relativity, and we explain this phenomenon based on a model of a superconducting cable.

A Novel Fault-location Method for HVDC Transmission Lines Based on Concentric Relaxation Principle and Wavelet Packet

2020 ◽  
Vol 13 (5) ◽  
pp. 705-716
Author(s):  
Congshan Li ◽  
Ping He ◽  
Feng Wang ◽  
Cunxiang Yang ◽  
Yukun Tao ◽  
...  
Keyword(s):  
Transmission Lines ◽  
Traveling Wave ◽  
Fault Location ◽  
Wave Attenuation ◽  
Wavelet Packet ◽  
Low Frequency ◽  
Evaluation Process ◽  
Location Method ◽  
Hvdc Transmission ◽  
Instantaneous Energy

Background: A novel fault location method of HVDC transmission line based on a concentric relaxation principle is proposed in this paper. Methods: Due to the different position of fault, the instantaneous energy measured from rectifier and inverter are different, and the ratio k between them is the relationship to the fault location d. Through the analysis of amplitude-frequency characteristics, we found that the wave attenuation characteristic of low frequency in the traveling wave is stable, and the amplitude of energy is larger, so we get the instantaneous energy ratio by using the low-frequency data. By using the method of wavelet packet decomposition, the voltage traveling wave signal was decomposed. Results: Finally, calculate the value k. By using the data fitting, the relative function of k and d can be got, that is the fault location function. Conclusion: After an exhaustive evaluation process considering different fault locations, fault resistances, and noise on the unipolar DC transmission system, four-machine two-area AC/DC parallel system, and an actual complex grid, the method presented here showed a very accurate and robust behavior.

scholarly journals MUTUAL COUPLING COEFFICIENTS OF ROTATING RECTANGULAR DIELECTRIC RESONATORS IN CUT-OFF RECTANGULAR WAVEGUIDE

2021 ◽  
pp. 48-54
Author(s):  
Alexander Trubin
Keyword(s):  
Transmission Lines ◽  
Rectangular Waveguide ◽  
Information Transfer ◽  
Dielectric Resonators ◽  
Coupling Coefficients ◽  
Metal Waveguide ◽  
Communication Devices ◽  
Dielectric Filter ◽  
Analytical Formulas ◽  
Analytical Expressions

Background. A further increase in the speed of information transfer is determined by more stringent requirements for the elements of communication devices. One of the most important components of such devices is various filters, which are often made on the basis of dielectric resonators. Calculation of the parameters of multi-section filters is impossible without further development of the theory of their design. The development of filter theory is based on electrodynamic modelling, which involves calculating the coupling coefficients of dielectric resonators in various transmission lines. Objective. The aim of the research is to calculate and study the coupling coefficients of rectangular dielectric resonators with a rectangular metal waveguide when their axes rotate. Investigation of new effects to improve the performance of filters and other devices based on them. Methods. Methods of technical electrodynamics are used to calculate and analyse the coupling coefficients. The end result is to obtain new analytical formulas for new structures with rectangular dielectric resonators, which make it possible to analyse and calculate their coupling coefficients. Results. New analytical expressions are found for the coupling coefficients of dielectric resonators with the rotation of their axes in a rectangular waveguide. Conclusions. The theory of designing filters based on new structures of dielectric resonators with rotation of their axes in metal waveguides has been expanded. New analytical relationships and new patterns of change in the coupling coefficients are found. Keywords: dielectric filter; rectangular dielectric resonator; rotation; coupling coefficients.

A new time coding approach for CTVEP-based brain-computer interface

2020 ◽  
Vol 20 (3) ◽  
pp. 743-757
Author(s):  
Teng Ma ◽  
Xuezhuan Zhao
Keyword(s):  
Information Transfer ◽  
High Performance ◽  
Visual Stimulation ◽  
Brain Computer Interface ◽  
Low Frequency ◽  
Computer Interface ◽  
Binary Codes ◽  
Frequency Change ◽  
Time Coding ◽  
New Time

The chromatic transient visual evoked potential (CTVEP)-based brain-computer interface (BCI) can provide safer and more comfortable stimuli than the traditional VEP-based BCIs due to its low frequency change and no luminance variation in the visual stimulation. However, it still generates relatively few codes that correspond to input commands to control the outside devices, which limits its application in the practical BCIs to some extent. Aiming to obtain more codes, we firstly proposes a new time coding technique to CTVEP-based BCI by utilizing a combination of two 4-bit binary codes to construct four 8-bit binary codes to increase the control commands to extend its application in practice. In the experiment, two time-encoded isoluminant chromatic stimuli are combined to serve as different commands for BCI control, and the results show that the high performance based on the new time coding approach with the average accuracy up to 90.28% and average information transfer rate up to 27.78 bits/min for BCI can be achieved. It turns out that the BCI system based on the proposed method is feasible, stable and efficient, which makes the method very suitable for the practical application of BCIs, such as military, entertainment and medical enterprise.

Multinephron dynamics on the renal vascular network

2013 ◽  
Vol 304 (1) ◽  
pp. F88-F102 ◽  
Author(s):  
Donald J. Marsh ◽  
Anthony S. Wexler ◽  
Alexey Brazhe ◽  
Dmitri E. Postnov ◽  
Olga V. Sosnovtseva ◽  
...  
Keyword(s):  
Blood Flow ◽  
Smooth Muscle ◽  
Information Transfer ◽  
Phase Synchronization ◽  
Low Frequency ◽  
Vascular Network ◽  
Tubuloglomerular Feedback ◽  
Symmetric Model ◽  
Flow Measurements ◽  
Electrical Signals

Tubuloglomerular feedback (TGF) and the myogenic mechanism combine in each nephron to regulate blood flow and glomerular filtration rate. Both mechanisms are nonlinear, generate self-sustained oscillations, and interact as their signals converge on arteriolar smooth muscle, forming a regulatory ensemble. Ensembles may synchronize. Smooth muscle cells in the ensemble depolarize periodically, generating electrical signals that propagate along the vascular network. We developed a mathematical model of a nephron-vascular network, with 16 versions of a single nephron model containing representations of both mechanisms in the regulatory ensemble, to examine the effects of network structure on nephron synchronization. Symmetry, as a property of a network, facilitates synchronization. Nephrons received blood from a symmetric electrically conductive vascular tree. Symmetry was created by using identical nephron models at each of the 16 sites and symmetry breaking by varying nephron length. The symmetric model achieved synchronization of all elements in the network. As little as 1% variation in nephron length caused extensive desynchronization, although synchronization was maintained in small nephron clusters. In-phase synchronization predominated among nephrons separated by one or three vascular nodes and antiphase synchronization for five or seven nodes of separation. Nephron dynamics were irregular and contained low-frequency fluctuations. Results are consistent with simultaneous blood flow measurements in multiple nephrons. An interaction between electrical signals propagated through the network to cause synchronization; variation in vascular pressure at vessel bifurcations was a principal cause of desynchronization. The results suggest that the vasculature supplies blood to nephrons but also engages in robust information transfer.

Prediction of Silencer Performance Using Transmission Line Theory

1971 ◽  
Vol 93 (4) ◽  
pp. 404-410
Author(s):  
R. J. Wells ◽  
R. B. Tatge
Keyword(s):  
Gas Turbine ◽  
Transmission Lines ◽  
Low Frequency ◽  
Frequency Range ◽  
Electrical Transmission ◽  
Transmission Line Theory ◽  
One Dimensional ◽  
Line Theory ◽  
Gas Turbine Exhaust ◽  
Turbine Exhaust

The size and cost of gas turbine exhaust silencers are largely set by low-frequency requirements. In that frequency range, the silencer cross-dimensions are small compared to the wavelength; it can therefore be considered to be one dimensional. Equations analogous to those governing electrical transmission lines can be written to predict the acoustical performance. Agreement between measured and predicted attenuation is good.

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