scholarly journals A grid-based nonlinear approach to noise reduction and deconvolution for coupled systems

2021 ◽  
Vol 417 ◽  
pp. 132819
Author(s):  
Samuel J. Araki ◽  
Justin W. Koo ◽  
Robert S. Martin ◽  
Ben Dankongkakul
Keyword(s):  
Noise Reduction ◽  
Coupled Systems ◽  
Nonlinear Approach ◽  
Grid Based

scholarly journals Sparse grid-based adaptive noise reduction strategy for particle-in-cell schemes

2021 ◽  
pp. 100094
Author(s):  
Sriramkrishnan Muralikrishnan ◽  
Antoine J. Cerfon ◽  
Matthias Frey ◽  
Lee F. Ricketson ◽  
Andreas Adelmann
Keyword(s):  
Noise Reduction ◽  
Sparse Grid ◽  
Reduction Strategy ◽  
Particle In Cell ◽  
Adaptive Noise ◽  
Grid Based

scholarly journals Systematic analysis of noise reduction properties of coupled and isolated feed-forward loops

2021 ◽  
Vol 17 (12) ◽  
pp. e1009622
Author(s):  
Suchana Chakravarty ◽  
Attila Csikász-Nagy
Keyword(s):  
Noise Reduction ◽  
Signaling Pathways ◽  
Complex Function ◽  
Coupled Systems ◽  
Inactivation Kinetics ◽  
Noise Filtering ◽  
Noisy Environment ◽  
Biological Noise ◽  
Systematic Analysis ◽  
Feed Forward

Cells can maintain their homeostasis in a noisy environment since their signaling pathways can filter out noise somehow. Several network motifs have been proposed for biological noise filtering and, among these, feed-forward loops have received special attention. Specific feed-forward loops show noise reducing capabilities, but we notice that this feature comes together with a reduced signal transducing performance. In posttranslational signaling pathways feed-forward loops do not function in isolation, rather they are coupled with other motifs to serve a more complex function. Feed-forward loops are often coupled to other feed-forward loops, which could affect their noise-reducing capabilities. Here we systematically study all feed-forward loop motifs and all their pairwise coupled systems with activation-inactivation kinetics to identify which networks are capable of good noise reduction, while keeping their signal transducing performance. Our analysis shows that coupled feed-forward loops can provide better noise reduction and, at the same time, can increase the signal transduction of the system. The coupling of two coherent 1 or one coherent 1 and one incoherent 4 feed-forward loops can give the best performance in both of these measures.

Satisfaction With Noise Reduction Circuits

1993 ◽  
Vol 2 (1) ◽  
pp. 51-53 ◽  
Author(s):  
Ruth A. Bentler
Keyword(s):  
Noise Reduction

Terrorist teams as loosely coupled systems.

2018 ◽  
Vol 73 (4) ◽  
pp. 491-503 ◽  
Author(s):  
Matthias Spitzmuller ◽  
Guihyun Park
Keyword(s):  
Coupled Systems ◽  
Loosely Coupled Systems ◽  
Loosely Coupled

КОНЦЕПЦІЯ СТВОРЕННЯ СИЛОВОЇ УСТАНОВКИ СІМЕЙСТВА РЕГІОНАЛЬНИХ ПАСАЖИРСЬКИХ ЛІТАКІВ АН-148/АН-158

2019 ◽  
pp. 50-63
Author(s):  
О. Д. Донець ◽  
В. П. Іщук
Keyword(s):  
Power Plant ◽  
Noise Reduction ◽  
Fuel Consumption ◽  
Electronic System ◽  
Electronic Control ◽  
Level Of Automation ◽  
Auxiliary Power ◽  
Power Plant Control ◽  
Technical Status ◽  
Air Intake

The basic results of calculation and research works carried out in the process of creation of power unit of regional passenger airplanes’ family are given. The design features of the propulsion engines and engine of the auxiliary power plant are described. The aforementioned propulsion system includes propulsion engines D-436-148 and engine AI-450-MS of auxiliary power plant. In order to comply with the requirements of Section 4 of the ICAO standard (noise reduction of the aircraft in site), in part of ensuring the noise reduction of engines, when creating the power plant of the An-148/An-158 aircraft family, a single- and double-layer acoustic filler was used in the structure of the engine nacelle and air intake. The use of electronic system for automatic control of propulsion engines such as FADEC and its integration into the digital airborne aircraft complex ensured the operation of engines, included in the power plant provided with high specific fuel consumption, as well as increased the level of automation of the power plant control and monitoring, and ensured aircraft automation landing in ICAO category 3A. In addition, the use of the aforementioned electronic system, allowed to operate the power plant of the aircraft in accordance with technical status. The use of the AI-450-MS auxiliary power plant with an electronic control system such as FADEC, and the drive of the service compressor from a free turbine, eliminated the effect of changes in power and air takeoff, on the deviation of the engine from optimal mode, which also minimized the fuel consumption. The use of fuel metering system TIS-158, allowed to ensure control of its condition and assemblies, without the use of auxiliary devices, built-in control means. In the fire protection system, the use of the electronic control and monitor unit, as well as the use of digital serial code for the exchange of information between the elements of the system and the aircraft systems, has reduced the number of connections, which increased the reliability of the system and reduced its weight characteristics.

AN IMPROVED ARMORED VEHICLE KRAZ “FIONA” NOISE SILENCER

2019 ◽  
pp. 21-26
Author(s):  
Volodymyr Fedorov ◽  
Vasyl’ Yanovsky ◽  
Dmytro Kovalshuk
Keyword(s):  
Noise Reduction ◽  
Speed Of Sound ◽  
Acoustic Waves ◽  
Noise Level ◽  
Combustion Engine ◽  
Environmental Aspect ◽  
Exhaust Gases ◽  
Ecological Requirements ◽  
On The Road ◽  
Armored Vehicle

Ecological requirements for cars grow from year to year, both in the world as a whole, and in Ukraine in particular. This is especially true of noise pollution. Additionally, noise reduction becomes relevant, taking into account the conduct of military operations during the last 5 years on the territory of Ukraine. The war has caused a special need for military vehicles for which masking properties are vital. Noise is a serious disincentive factor. Therefore, its reduction for a military vehicle, apart from the environmental aspect, is of a purely military nature, that is, it is extremely important. The car has many sources of noise there are many ways to deal with them. One of the most powerful source of noise is the sleeping bag. This kind of noise is reduced by means of silencers of noise. The vast majority of silencer data in the basis of its design has a reactive (or resonant) muffler. To calculate the jet silencer you must know the speed of sound in the sleeping bags. In order to increase the acoustic efficiency of reactive and resonant mufflers of exhaust gases noise of the ICE of cars, an experimental method was proposed for determining the speed of sound in the sleighs. Implementation of the method is carried out by measuring the attenuation of acoustic waves. The noise level of the bedrooms is measured without silencer and silencer. Based on the data obtained, the noise reduction performance of the residual is established. From the well-known formula, based on the calculation of the efficiency of the silencing of a jet muffler, a formula is obtained for calculating the speed of sound in the sleeping quays. In this formula, all parameters are known: the level of silencer efficiency, the noise level of the sleeping, the ratio of areas of cross sections of the muffler and the inlet pipe and the length of the muffler. The sound speed thus established can continue to be used not only for engines of the type for which measurements and calculations were made, but also with a certain approximation for some other types of engines. This method provides high accuracy for determining the required parameter. In the given work on the example of the armored car KrAZ “Fiona” the calculation of efficiency increase of the reactive silencer is made due to the above-mentioned method. Also, the projected decrease in the external noise level of the KrAZ Armored Vehicle “Fiona” is considered by determining the speed of sound in the recesses on the trunk cycle on the road with acceleration up to speed of 50 km/h (75 km/h) and the movement with this speed, as well as when driving at a speed of 45 km/h. Keywords: transport, armored car, internal combustion engine, exhaust, exhaust gases, noise, source, acoustic efficiency, acoustic efficiency, speed of sound, jet muffler.

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