scholarly journals Frequency-domain formulation of signal propagation in multistrip Resistive Plate Chambers and its low-loss, weak-coupling analytical approximation

2013 ◽  
Vol 8 (08) ◽  
pp. P08007-P08007 ◽  
Author(s):  
P Fonte
2021 ◽  
Vol 16 (01) ◽  
pp. P01001-P01001
Author(s):  
X.Y. Xie ◽  
Q.Y. Li ◽  
C.H. Tian ◽  
M. Yuan ◽  
Y.J. Sun

Author(s):  
Ashley M. Patton ◽  
Gabriel C. Rau ◽  
Peter J. Cleall ◽  
Mark O. Cuthbert

AbstractHydraulic properties of coastal, urban aquifers vary spatially and temporally with the complex dynamics of their hydrogeology and the heterogeneity of ocean-influenced hydraulic processes. Traditional aquifer characterisation methods are expensive, time-consuming and represent a snapshot in time. Tidal subsurface analysis (TSA) can passively characterise subsurface processes and establish hydro-geomechanical properties from groundwater head time-series but is typically applied to individual wells inland. Presented here, TSA is applied to a network of 116 groundwater boreholes to spatially characterise confinement and specific storage across a coastal aquifer at city-scale in Cardiff (UK) using a 23-year high-frequency time-series dataset. The dataset comprises Earth, atmospheric and oceanic signals, with the analysis conducted in the time domain, by calculating barometric response functions (BRFs), and in the frequency domain (TSA). By examining the damping and attenuation of groundwater response to ocean tides (OT) with distance from the coast/rivers, a multi-borehole comparison of TSA with BRF shows this combination of analyses facilitates disentangling the influence of tidal signals and estimation of spatially distributed aquifer properties for non-OT-influenced boreholes. The time-series analysed covers a period pre- and post-impoundment of Cardiff’s rivers by a barrage, revealing the consequent reduction in subsurface OT signal propagation post-construction. The results indicate that a much higher degree of confined conditions exist across the aquifer than previously thought (specific storage = 2.3 × 10−6 to 7.9 × 10−5 m−1), with implications for understanding aquifer recharge, and informing the best strategies for utilising groundwater and shallow geothermal resources.


Complexity ◽  
2018 ◽  
Vol 2018 ◽  
pp. 1-12
Author(s):  
Pavel Orlov ◽  
Talgat Gazizov

This paper presents a unified description of a new approach for contactless detection, identification, and diagnostics of electrical connections and describes an idea and principles of using modal probing for these tasks. Simulation and experimental results on pulsed signal propagation through flat cables demonstrate the modal decomposition of a pulsed signal, which varies depending on the state of the probed wire. It is shown that the presented tasks can be solved by modal probing. The article also considers the analysis of modal distortions in frequency domain and gives the formula for its practical use. This formula can be useful when the pulse duration time is longer than the minimum of mode delay difference. In conclusion, we present further development ideas of the modal probing.


Author(s):  
Hiroshi Imagawa ◽  
Kunio Emoto ◽  
Hiroshi Murase ◽  
Hiroshi Koyama ◽  
Seiji Wakabayashi ◽  
...  

Geophysics ◽  
2006 ◽  
Vol 71 (4) ◽  
pp. W29-W40 ◽  
Author(s):  
Lars O. Løseth ◽  
Hans M. Pedersen ◽  
Bjørn Ursin ◽  
Lasse Amundsen ◽  
Svein Ellingsrud

Low-frequency electromagnetic (EM) signal propagation in geophysical applications is sometimes referred to as diffusion and sometimes as waves. In the following we discuss the mathematical and physical approaches behind the use of the different terms. The basic theory of EM wave propagation is reviewed. From a frequency-domain description we show that all of the well-known mathematical tools of wave theory, including an asymptotic ray-series description, can be applied for both nondispersive waves in nonconductive materials and low-frequency waves in conductive materials. We consider the EM field from an electric dipole source and show that a common frequency-domain description yields both the undistorted pulses in nonconductive materials and the strongly distorted pulses in conductive materials. We also show that the diffusion-equation approximation of low-frequency EM fields in conductive materials gives the correct mathematical description, and this equation has wave solutions. Having considered both a wave-picture approach and a diffusion approach to the problem, we discuss the possible confusion that the use of these terms might lead to.


2021 ◽  
Vol 92 (3) ◽  
pp. 035109
Author(s):  
Yundong Ren ◽  
Mucheng Li ◽  
Subhrodeep Ray ◽  
Brandon Johann Bozeat ◽  
Yuxiang Liu

2019 ◽  
pp. 17-23
Author(s):  
O. Kostyria ◽  
V. Storozhenko ◽  
V. Naumenko

Multipath propagation of radio waves negatively affects to the performance of telecommunications and radio navigation systems [1, 3]. When performing time and frequency synchronization tasks of spatially separated standards, the multi­path signal propagation aggravates the probabi­lity of a correct synchronization and introduces an error. The presence of a multipath signal reduces the signal-to-noise ratio in the received signal, which in turn causes an increase in the synchronization error. The mathematical models of multipath interference suppression in the time and in the frequency domain are presented in the article. Compared to time processing, processing in the frequency domain reduces computational costs. The operation of suppression in the time domain has been verified experimentally.


2016 ◽  
Vol 7 ◽  
pp. BECB.S38554 ◽  
Author(s):  
Saurabh Chaubey ◽  
Shikha J. Goodwin

Multiple sclerosis is a disease caused by demyelination of nerve fibers. In order to determine the loss of signal with the percentage of demyelination, we need to develop models that can simulate this effect. Existing time-based models does not provide a method to determine the influences of demyelination based on simulation results. Our goal is to develop a system identification approach to generate a transfer function in the frequency domain. The idea is to create a unified modeling approach for neural action potential propagation along the length of an axon containing number of Nodes of Ranvier (N). A system identification approach has been used to identify a transfer function of the classical Hodgkin-Huxley equations for membrane voltage potential. Using this approach, we model cable properties and signal propagation along the length of the axon with N node myelination. MATLAB/ Simulink platform is used to analyze an N node-myelinated neuronal axon. The ability to transfer function in the frequency domain will help reduce effort and will give a much more realistic feel when compared to the classical time-based approach. Once a transfer function is identified, the conduction as a cascade of each linear time invariant system-based transfer function can be modeled. Using this approach, future studies can model the loss of myelin in various parts of nervous system.


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