Sub-Nyquist Sampling of Multiple Exponentially Damped Sinusoids with Feedback Structure

2021 ◽  
pp. 1-1
Author(s):  
Guoxing Huang ◽  
An Ni ◽  
Weidang Lu ◽  
Hong Peng ◽  
Jingwen Wang
Keyword(s):  
Feedback Structure

Feedback structure and EFAS flood warning verification for the rivers in the northwestern Russian Federation

2020 ◽  
Vol 4 ◽  
pp. 96-109
Author(s):  
A.V. Romanov ◽  
◽  
M.V. Yachmenova ◽  
Keyword(s):  
Russian Federation ◽  
Forecast Accuracy ◽  
Warning System ◽  
General Description ◽  
System Quality ◽  
Flood Warning ◽  
Forecast Lead Time ◽  
Feedback Structure ◽  
The Russian Federation ◽  
Flood Warning System

Based on the example of flood warning data provided by EFAS for the territory of Northwestern Administration for Hydrometeorology and Environmental Monitoring in 2018-2020, the structure of the systematized issues of the EFAS portal is analyzed. The issues determine a feedback for the year-round monitoring of the accuracy of flood forecasting using the LISFLOOD base model, as well as its calibration. Several most important feedback sections are highlighted, that allow improving significantly a procedure for the quantitative and qualitative differentiated assessment of short- and medium-range flood forecasts. Using the results of the numerical analysis, a general description of the EFAS flood warning system quality and the prospects for the participation of the Russian Federation in it are given. Keywords: flooding, hydrological forecasts, forecast lead time, feedback, forecast accuracy

scholarly journals MRAS-Based Switching Linear Feedback Strategy for Sensorless Speed Control of Induction Motor Drives

Energies ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3083
Author(s):  
Mohamed Amine Fnaiech ◽  
Jaroslaw Guzinski ◽  
Mohamed Trabelsi ◽  
Abdellah Kouzou ◽  
Mohamed Benbouzid ◽  
...  
Keyword(s):  
Sliding Mode Control ◽  
Induction Motor ◽  
Sliding Mode ◽  
Good Control ◽  
Motor Drives ◽  
Linear Feedback ◽  
Mode Control ◽  
Model Reference Adaptive System ◽  
Feedback Structure ◽  
Model Reference Adaptive

This paper presents a newly designed switching linear feedback structure of sliding mode control (SLF-SMC) plugged with an model reference adaptive system (MRAS) based sensorless field-oriented control (SFOC) for induction motor (IM). Indeed, the performance of the MRAS depends mainly on the operating point and the parametric variation of the IM. Hence, the sliding mode control (SMC) could be considered a good control alternative due to its easy implementation and robustness. Simulation and experimentation results are presented to show the superiority of the proposed SLF-SMC technique in comparison with the classical PI controller under different speed ranges and inertia conditions.

IDENTIFICATIONS OF HASLER'S CLASSES OF LINEAR RESISTIVE CIRCUIT STRUCTURES

2004 ◽  
Vol 13 (05) ◽  
pp. 957-980
Author(s):  
J. CEL
Keyword(s):  
Sufficient Conditions ◽  
Input Power ◽  
Maximal Entropy ◽  
Cactus Graph ◽  
Resistance Function ◽  
Total Input ◽  
Feedback Structure ◽  
Ill Posed ◽  
System Of Parameters ◽  
Necessary And Sufficient

Formulae on first and second derivatives of various functions associated with a linear nullator–norator–resistance network such as total input power, driving-point and transfer resistances with respect to parameters are established. As a consequence, the concavity of the driving-point resistance with respect to the system of parameters is obtained which generalizes a scalar result of Schneider. An example is given showing that the driving-point resistance R of a nonreciprocal one-port is not monotone or convex or concave with respect to the system of resistances which shows that the Cohn–Vratsanos and the Shannon–Hagelbarger theorems which characterize R of reciprocal one-port cannot be extended in this way. Next, a simplified variant of the Shannon–Hagelbarger theorem is used to derive separate necessary and sufficient conditions characterizing always well-posed, sometimes ill-posed and always ill-posed classes of linear resistive circuit structures introduced and characterized by Hasler, both new in formulation and proof. This reveals that the form of the second partial derivative of the resistance function is responsible for various kinds of the structural solvability of linear circuits. Alternative "if and only if" criteria for these classes are established. They involve replacements of reciprocal circuit elements by combinations of contractions and removals leading to pairs of complementary directed nullator and directed norator trees with appropriately defined signs, and resemble therefore earlier famous Willson–Nielsen feedback structure and Chua–Nishi cactus graph criteria for circuits containing traditional controlled sources. Finally, the qualitative parts of the Cohn–Vratsanos and the Shannon–Hagelbarger theorems are shown to be simple consequences of much more general principles governing all aspects of life, such as maximal entropy and energy conservation laws.

scholarly journals Modeling, Analysis, and Optimal Design of the Automotive Transmission Ball Capsule System

2010 ◽  
Vol 132 (2) ◽  
Author(s):  
Xingyong Song ◽  
Mohd Azrin Mohd Zulkefli ◽  
Zongxuan Sun ◽  
Hsu-Chiang Miao
Keyword(s):  
Slope Angle ◽  
Fast Response ◽  
Optimal Shape ◽  
Effective Control ◽  
Shift Control ◽  
Automotive Transmission ◽  
Modeling Analysis ◽  
Clutch Engagement ◽  
Feedback Structure ◽  
Capsule Dynamics

Clutch shift control is critical for the performance and fuel economy of automotive transmissions, including both automatic and hybrid transmissions. Among all the factors that influence clutch shift control, clutch fill and clutch engagement are crucial to realize a fast and smooth clutch shift. When the clutch is not engaged, the fluid held by the centrifugal force inside of the clutch chamber, which introduces additional pressure that will affect the subsequent clutch fill and engagement processes, should be released. To realize this function, a ball capsule system is introduced and mounted on the clutch chamber. When the clutch chamber is ready to be filled for engagement, the ball capsule needs to close quickly and remain closed until the clutch is disengaged. It is also desirable to have an appropriate closing velocity for the ball capsule to minimize noise and wear. In this paper, the ball capsule dynamics is modeled, in which the derivation of the ball capsule throttling area is considered novel and critical because of its asymmetrical nature. Through this, the ball capsule’s intrinsic positive feedback structure is also revealed, which is considered to be the key to realize a fast response. Moreover, through the system dynamics analysis, the slope angle of the capsule is found to be an effective control parameter for system performance and robustness. To this end, the optimal shape of the capsule is designed using dynamic programming to achieve the desired performance.

scholarly journals Tunable phenotypic variability through an autoregulatory alternative sigma factor circuit

2020 ◽  
Author(s):  
Christian P. Schwall ◽  
Torkel Loman ◽  
Bruno M.C. Martins ◽  
Sandra Cortijo ◽  
Casandra Villava ◽  
...  
Keyword(s):  
Environmental History ◽  
Stress Level ◽  
Sigma Factor ◽  
Phenotypic Variability ◽  
Time Lapse ◽  
Alternative Sigma Factor ◽  
Bacterial Populations ◽  
Time Lapse Microscopy ◽  
Genetic Perturbations ◽  
Feedback Structure

AbstractGenetically identical individuals in bacterial populations can display significant phenotypic variability. This variability can be functional, for example by allowing a fraction of stress prepared cells to survive an otherwise lethal stress. The optimal fraction of stress prepared cells depends on environmental conditions. However, how bacterial populations modulate their level of phenotypic variability remains unclear. Here we show that the alternative sigma factor σV circuit in B. subtilis generates functional phenotypic variability that can be tuned by stress level, environmental history, and genetic perturbations. Using single-cell time-lapse microscopy and microfluidics, we find the fraction of cells that immediately activate σV under lysozyme stress depends on stress level and on a memory of previous stress. Iteration between model and experiment reveals that this tunability can be explained by the autoregulatory feedback structure of the sigV operon. As predicted by the model, genetic perturbations to the operon also modulate the response variability. The conserved sigma-anti-sigma autoregulation motif is thus a simple mechanism for bacterial populations to modulate their heterogeneity based on their environment.

scholarly journals Minimax based congestion control for TCP network systems with UDP flows

2018 ◽  
Vol 210 ◽  
pp. 03005 ◽  
Author(s):  
Yuanwei Jing ◽  
Zanhua Li ◽  
Georgi Dimirovski
Keyword(s):  
Congestion Control ◽  
Control Algorithm ◽  
State Feedback ◽  
Asymptotically Stable ◽  
Network Systems ◽  
Backstepping Approach ◽  
Congestion Control Algorithm ◽  
Feedback Structure ◽  
Simulation Results ◽  
Tcp Network

The congestion control problem for TCP network systems with UDP flows is considered. A nonlinear TCP network model with strict-feedback structure is established. The unknown UDP flow is considered as the disturbance to the system, and the maximum UDP flow is calculated by using the minimax approach. And then, a congestion control algorithm is proposed by using backstepping approach. Further, a state-feedback congestion controller is presented to make the TCP networks asymptotically stable. The simulation results show the superiority and feasibility of the proposed method.

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