Investigation of noise amplification questions in satellite jitter detected from CCDs’ parallax observation imagery: A case for 3 CCDs

The current paper presents a robust control method that combines sliding-mode control (SMC) and quantitative feedback theory (QFT) for designing a driver seat of a heavy vehicle to reduce driver fatigue. A mathematical model is considered to analyse tracking control characteristics through computer simulation in order to demonstrate the effectiveness of the proposed control methodology. The SMC is used to track the trajectory of the desired motion behaviour of the seat. However, when the system enters into sliding regime, chattering occurs owing to switching delays as well as vehicle system vibrations. The chattering is eliminated with the introduction QFT inside the boundary layer to ensure smooth tracking. Furthermore, using SMC alone requires higher actuator forces for tracking than using both the control schemes together, and causes various problems in selecting hardware. Problems with noise amplification, resonances, presence of uncertainties, and unmodelled high-frequency dynamics can largely be avoided with the use of QFT over other optimization methods. The main contribution of the present paper is to provide guidance in designing the controller to reduce heavy vehicle seat vibration so that the driver's sensation of comfort maintains a certain level at all times.

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GaN HEMTs for low-noise amplification — status and challenges

2017 Integrated Nonlinear Microwave and Millimetre-wave Circuits Workshop (INMMiC) ◽

10.1109/inmmic.2017.7927327 ◽

2017 ◽

Cited By ~ 3

Author(s):

Matthias Rudolph

Keyword(s):

Low Noise ◽

Gan Hemts ◽

Noise Amplification

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Mechanism of broadband jet noise amplification and suppression undercontrolled excitation

10.2514/6.1984-2319 ◽

1984 ◽

Cited By ~ 1

Author(s):

B. M. Q. ZAMAN

Keyword(s):

Jet Noise ◽

Noise Amplification

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Noise amplification of periodic nonuniform sampling

IEEE Transactions on Signal Processing ◽

10.1109/78.815502 ◽

2000 ◽

Vol 48 (1) ◽

pp. 275-277 ◽

Cited By ~ 20

Author(s):

D. Seidner ◽

M. Feder

Keyword(s):

Nonuniform Sampling ◽

Noise Amplification

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Improved k-t PCA Algorithm Using Artificial Sparsity in Dynamic MRI

Computational and Mathematical Methods in Medicine ◽

10.1155/2017/4816024 ◽

2017 ◽

Vol 2017 ◽

pp. 1-12

Author(s):

Yiran Wang ◽

Zhifeng Chen ◽

Jing Wang ◽

Lixia Yuan ◽

Ling Xia ◽

...

Keyword(s):

Mr Imaging ◽

Principal Component ◽

Dynamic Mri ◽

Reconstruction Error ◽

Reduction Factor ◽

Error Performance ◽

Spatiotemporal Resolution ◽

Noise Amplification ◽

Pca Algorithm

The k-t principal component analysis (k-t PCA) is an effective approach for high spatiotemporal resolution dynamic magnetic resonance (MR) imaging. However, it suffers from larger residual aliasing artifacts and noise amplification when the reduction factor goes higher. To further enhance the performance of this technique, we propose a new method called sparse k-t PCA that combines the k-t PCA algorithm with an artificial sparsity constraint. It is a self-calibrated procedure that is based on the traditional k-t PCA method by further eliminating the reconstruction error derived from complex subtraction of the sampled k-t space from the original reconstructed k-t space. The proposed method is tested through both simulations and in vivo datasets with different reduction factors. Compared to the standard k-t PCA algorithm, the sparse k-t PCA can improve the normalized root-mean-square error performance and the accuracy of temporal resolution. It is thus useful for rapid dynamic MR imaging.

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Design Tradeoffs

Biomolecular Feedback Systems ◽

10.23943/princeton/9780691161532.003.0007 ◽

2014 ◽

Author(s):

Richard M. Murray

Keyword(s):

Intrinsic Noise ◽

Design Phase ◽

Host Organism ◽

Biological Noise ◽

Common Resources ◽

Environment Changes ◽

Cellular Environment ◽

Design Tradeoffs ◽

Noise Amplification ◽

Biomolecular Reactions

This chapter describes some of the design tradeoffs arising from the interaction between synthetic circuits and the host organism. It first considers the effects of competition for shared cellular resources on circuits' behavior. In particular, circuits (endogenous and exogenous) share a number of cellular resources. The insertion or induction of synthetic circuits in the cellular environment changes for these resources, with possibly undesired repercussions on the functioning of the circuits. Independent circuits may become coupled when they share common resources that are not in overabundance. This fact leads to constraints among the concentrations of proteins in synthetic circuits, which should be accounted for in the design phase. Next, the chapter looks at the effect of biological noise on the design of devices requiring high gains. Specifically, the chapter illustrates possible design tradeoffs between retroactivity attenuation and noise amplification that emerge due to the intrinsic noise of biomolecular reactions.

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Experimental Implementation of a Low-Cost, Fully-Analog Self-Jamming Canceller for UHF RFID Devices

Electronics ◽

10.3390/electronics9050786 ◽

2020 ◽

Vol 9 (5) ◽

pp. 786 ◽

Cited By ~ 1

Author(s):

Massimiliano Rossi ◽

Riccardo Liberati ◽

Marco Frasca ◽

John Richardson

Keyword(s):

Low Cost ◽

Low Noise ◽

Modular System ◽

Uhf Rfid ◽

Rf Receiver ◽

Experimental Implementation ◽

And Performance ◽

Modular Technology ◽

Noise Amplification ◽

Theoretical Simulations

It is quite common for transceivers to operate with the RF receiver and transmitter working on different time slots. Typical applications are radars and transceivers in the field of communications. Generally, the receiver is turned off when the transmitter broadcasts and vice versa. This is done in order to prevent the transmitter from blinding the receiver or causing the RF low noise amplification (LNA) stage to saturate. When keeping a receiver active, some leakage of RF energy is inevitable, and therefore shielding is applied to mitigate spurious signals. However, there are many applications wherein the receiver cannot be turned off. To address these applications, we investigate the design and performance of a fully-analog self-jamming canceller able to operate in UHF (Ultra High Frequency) RFID devices. While the traditional cost to design and build this type of topology can be quite high, our proposal is based on a low-cost physical approach. In addition to using common SMT (Surface Mount Technology) devices, we leveraged a new piece of modular technology offered by X-Microwave which allows designers to easily produce RF solutions with a broad portfolio of modular system drop-in blocks. A prototype was realized and the measured results are in close agreement with theoretical simulations. Significant damping of the leaked signal in the receiving channel was realized.

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