scholarly journals Role of the driver in the dynamics of a coupled-map model of the magnetotail: Does the magnetosphere act as a low-pass filter?

2000 ◽  
Vol 105 (A12) ◽  
pp. 27665-27672 ◽  
Author(s):  
J. Takalo ◽  
K. Mursula ◽  
J. Timonen
Keyword(s):  
Sensors ◽  
2021 ◽  
Vol 21 (13) ◽  
pp. 4305
Author(s):  
Takamasa Terada ◽  
Masahiro Toyoura ◽  
Takahide Sato ◽  
Xiaoyang Mao

In this work, we propose a fabric electrode with a special structure that can play the role of a noise reduction filter. Fabric electrodes made of the conductive fabric have been used for long-term ECG measurements because of their flexibility and non-invasiveness; however, due to the large impedance between the skin and the fabric electrodes, noise is easily introduced into the ECG signal. In contrast to conventional work, in which chip-type passive elements are glued to the electrode to reduce noise, the proposed electrode can obtain a noise-reduced ECG by changing the structure of fabric. Specifically, the proposed electrode was folded multiple times to form a capacitor with a capacitance of about 3 nF. It is combined with the skin-electrode impedance to form a low-pass filter. In the experiment, we made a prototype of the electrodes and measured ECG at rest and during EMG-induced exercise. As a result, the SNR values at rest and during exercise were improved about 12.02 and 10.29 , respectively, compared with the fabric electrode without special structure. In conclusion, we have shown that changing the fabric electrode structure effectively removes noise in ECG measurement.


Author(s):  
I. M. Yasinskiy ◽  
A. I. Tyumentsev ◽  
A. N. Yakovlev

The possibilities of realizing retunable rejection filters are considered, in which two-pole networks are introduced into the low-pass filter, which play the role of narrow-band rejection circuits. Methods for analyzing rejection circuits and formulas for calculating elements are presented.


Author(s):  
Ibtissame Moumane ◽  
Jamal Zbitou ◽  
M. Latrach ◽  
A. Errkik ◽  
O. Chakkor

In this paper we present a new design of a photonic transmitter based on multi-layers substrate GaAs and using for generation of THz waves. The proposed circuit is composed from a photodetector (PD) “which converts the light to the electrical signal”, THz Antenna, low-pass filter and DC probe. Firstly we have optimized the THz antenna using an EM solver which is Momentum integrated in ADS “Advanced Design System”.Then we have optimized the low pass filter which plays the role of inductance that is an RF choke permiting to separate the RF signal from the DC one. Finally, we have associated the different components, add the DC probe and simulate the whole proposed system. The dimensions of the final circuit are 400.317x167.16 UM2 . The obtain results permit to validate the final circuit at THz and make it suitable for THz applications.


2019 ◽  
Vol 31 (11) ◽  
pp. 2212-2251 ◽  
Author(s):  
Terry Elliott

Repeated stimuli that are spaced apart in time promote the transition from short- to long-term memory, while massing repetitions together does not. Previously, we showed that a model of integrative synaptic plasticity, in which plasticity induction signals are integrated by a low-pass filter before plasticity is expressed, gives rise to a natural timescale at which to repeat stimuli, hinting at a partial account of this spacing effect. The account was only partial because the important role of neuromodulation was not considered. We now show that by extending the model to allow dynamic integrative synaptic plasticity, the model permits synapses to robustly discriminate between spaced and massed repetition protocols, suppressing the response to massed stimuli while maintaining that to spaced stimuli. This is achieved by dynamically coupling the filter decay rate to neuromodulatory signaling in a very simple model of the signaling cascades downstream from cAMP production. In particular, the model's parameters may be interpreted as corresponding to the duration and amplitude of the waves of activity in the MAPK pathway. We identify choices of parameters and repetition times for stimuli in this model that optimize the ability of synapses to discriminate between spaced and massed repetition protocols. The model is very robust to reasonable changes around these optimal parameters and times, but for large changes in parameters, the model predicts that massed and spaced stimuli cannot be distinguished or that the responses to both patterns are suppressed. A model of dynamic integrative synaptic plasticity therefore explains the spacing effect under normal conditions and also predicts its breakdown under abnormal conditions.


2017 ◽  
Vol E100.C (10) ◽  
pp. 858-865 ◽  
Author(s):  
Yohei MORISHITA ◽  
Koichi MIZUNO ◽  
Junji SATO ◽  
Koji TAKINAMI ◽  
Kazuaki TAKAHASHI

2016 ◽  
Vol 15 (12) ◽  
pp. 2579-2586
Author(s):  
Adina Racasan ◽  
Calin Munteanu ◽  
Vasile Topa ◽  
Claudia Pacurar ◽  
Claudia Hebedean

Author(s):  
Nanan Chomnak ◽  
Siradanai Srisamranrungrueang ◽  
Natapong Wongprommoon
Keyword(s):  

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