On the correlation “powder dispersivity – hysteresis characteristics” for (Sm,Zr)(Co,Cu,Fe)z-based magnets

2018 ◽  
pp. 47-52
Author(s):  
N.A. Dormidontov ◽  
◽  
G.S. Burkhanov ◽  
N.B. Kolchugina ◽  
A.G. Dormidontov ◽  
...  
Keyword(s):  
Hysteresis Characteristics

scholarly journals Hysteresis Modeling and Compensation of Fast Steering Mirrors with Hysteresis Operator Based Back Propagation Neural Networks

Micromachines ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 732
Author(s):  
Kairui Cao ◽  
Guanglu Hao ◽  
Qingfeng Liu ◽  
Liying Tan ◽  
Jing Ma
Keyword(s):  
Neural Network ◽  
Back Propagation ◽  
Hysteresis Model ◽  
Cooperative Movement ◽  
Hysteresis Operator ◽  
The Neural Network ◽  
Hysteresis Nonlinearity ◽  
Hysteresis Modeling ◽  
Hysteresis Characteristics ◽  
Inverse Hysteresis

Fast steering mirrors (FSMs), driven by piezoelectric ceramics, are usually used as actuators for high-precision beam control. A FSM generally contains four ceramics that are distributed in a crisscross pattern. The cooperative movement of the two ceramics along one radial direction generates the deflection of the FSM in the same orientation. Unlike the hysteresis nonlinearity of a single piezoelectric ceramic, which is symmetric or asymmetric, the FSM exhibits complex hysteresis characteristics. In this paper, a systematic way of modeling the hysteresis nonlinearity of FSMs is proposed using a Madelung’s rules based symmetric hysteresis operator with a cascaded neural network. The hysteresis operator provides a basic hysteresis motion for the FSM. The neural network modifies the basic hysteresis motion to accurately describe the hysteresis nonlinearity of FSMs. The wiping-out and congruency properties of the proposed method are also analyzed. Moreover, the inverse hysteresis model is constructed to reduce the hysteresis nonlinearity of FSMs. The effectiveness of the presented model is validated by experimental results.

Unstart/restart hysteresis characteristics analysis of an over–under TBCC inlet caused by backpressure and splitter

2018 ◽  
Vol 72 ◽  
pp. 418-425 ◽  
Author(s):  
Nan Li ◽  
Juntao Chang ◽  
Chenzhong Jiang ◽  
Daren Yu ◽  
Wen Bao ◽  
...  
Keyword(s):  
Characteristics Analysis ◽  
Hysteresis Characteristics

Development of an Evaluation Method for Seismic Isolation Systems of Nuclear Power Facilities: Part 6 — Scaled Tests to Obtain Basic Characteristics of Lead Rubber Bearing

2014 ◽  
Author(s):  
Tsutomu Hirotani ◽  
Ryota Takahama ◽  
Masaki Yukawa ◽  
Hiroshi Hibino ◽  
Yuji Aikawa ◽  
...  
Keyword(s):  
Nuclear Power ◽  
Seismic Isolation ◽  
Evaluation Method ◽  
Loading Test ◽  
Rubber Bearing ◽  
Lead Rubber Bearing ◽  
Basic Characteristics ◽  
Isolation Systems ◽  
Seismic Isolation Systems ◽  
Hysteresis Characteristics

This paper provides a series comprising the “Development of Evaluation Method for Seismic Isolation Systems of Nuclear Power Facilities”. Part 6 presents scaled tests for Lead Rubber Bearing (LRB) newly developed for this project. Following tests are performed to obtain the basic characteristics of LRB,. (1) Horizontal and Vertical Simultaneous Loading Test: LRBs with diameter of 250mm are tested dynamically under simultaneous axial and lateral loading. The hysteresis characteristics is not changed under compressive load although it is changed under tensile load. (2) Basic Break Test: LRBs with a diameter of 800mm are tested statically under various combinations of axial and lateral forces. The hysteresis characteristics model of LRB is determined by this test. It is confirmed that the breaking strain of LRB under compression load exceeds 450%. (3) Horizontal Hardening and Vertical Softening Test: For LRBs with a diameter of 1200 mm, 75% scale of actual LRB are tested statically for horizontal hardening and vertical softening regions. It is confirmed that the hysteresis model which is developed by smaller LRBs is applicable to these large scale models.

A Mathematical Calculation Method for Hysteresis Characteristics Analysis of Arc-Shaped Finger Seal

2020 ◽  
Author(s):  
Chun-Hua Du ◽  
Yan-Chao Zhang ◽  
Ya-Hui Cui ◽  
Shu-Na Dong ◽  
Hong-Hu Ji ◽  
...  
Keyword(s):  
Mathematical Model ◽  
Structural Parameters ◽  
Maximum Error ◽  
Calculation Model ◽  
Correction Coefficient ◽  
Research Results ◽  
Characteristics Analysis ◽  
Leakage Characteristics ◽  
The Mathematical Model ◽  
Hysteresis Characteristics

Abstract In order to accurately predict the hysteresis characteristics of finger seal, the minimum hysteresis which can directly reflect the hysteresis of finger seal is proposed to characterize the hysteresis of finger seal. The mathematical model for calculating the minimum hysteresis of finger seal is established, the correction coefficient in the mathematical model is determined, and the mathematical model is verified by experiments. The influence of the structure and working condition parameters of finger laminates on the hysteresis characteristics is studied based on the modified calculation model, and the rule of influence is obtained in the end. Research results show that the maximum error between the leakage characteristics numerical calculation of finger seal base on modified calculation model and the experiment results is 7.64%, and the mathematical model of the minimum hysteresis is reasonable and reliable. The descending order of influence degree of structural parameters on the hysteresis characteristics of finger seal is: thickness of each finger laminate, finger repeat angle, arc radius of the finger beam arcs‘ centers, diameter of the finger base circle, width of the interstice between fingers, arc radius of finger beam. The research results provide a theoretical basis for further research on the influence of hysteresis on the finger seal leakage characteristics and the optimal design of finger seal structure.

The Hysteresis Characteristics of Some Industrial PRTs

2010 ◽  
Vol 31 (8-9) ◽  
pp. 1676-1684 ◽  
Author(s):  
D. R. White ◽  
C. L. Jongenelen ◽  
P. Saunders
Keyword(s):  
Hysteresis Characteristics

scholarly journals Predicting Brain Occupancy from Plasma Levels using PET: Superiority of Combining Pharmacokinetics with Pharmacodynamics while Modeling the Relationship

2011 ◽  
Vol 32 (4) ◽  
pp. 759-768 ◽  
Author(s):  
Euitae Kim ◽  
Oliver D Howes ◽  
Bo-Hyung Kim ◽  
Jae Min Jeong ◽  
Jae Sung Lee ◽  
...  
Keyword(s):  
Dopamine Receptor ◽  
Receptor Occupancy ◽  
Analysis Approach ◽  
Reliable Prediction ◽  
Positron Emission ◽  
Time Courses ◽  
The Relationship ◽  
The Brain ◽  
Serial Measurements ◽  
Hysteresis Characteristics

Positron emission tomography (PET) studies of dopamine receptor occupancy can be used to assess dosing of antipsychotics. Typically, studies of antipsychotics have applied pharmacodynamic (PD) modeling alone to characterize the relationship between antipsychotic dose and its effect on the brain. However, a limitation of this approach is that it does not account for the discrepancy between the time courses of plasma concentration and receptor occupancy by antipsychotics. Combined pharmacokinetic—PD (PK—PD) modeling, by incorporating the time dependence of occupancy, is better suited for the reliable analysis of the concentration—occupancy relationship. To determine the effect of time on the concentration—occupancy relationship as a function of analysis approach, we measured dopamine receptor occupancy after the administration of aripiprazole using [11C]raclopride PET and obtained serial measurements of the plasma aripiprazole concentration in 18 volunteers. We then developed a PK—PD model for the relationship, and compared it with conventional approach (PD modeling alone). The hysteresis characteristics were observed in the competitor concentration—occupancy relationship and the value of EC50 was different according to the analysis approach ( EC50 derived from PD modeling alone = 11.1 ng/mL (95% confidence interval (CI) = 10.1 to 12.1); while that derived from combined PK—PD modeling = 8.63 ng/mL (95% CI = 7.75 to 9.51)). This finding suggests that PK—PD modeling is required to obtain reliable prediction of brain occupancy by antipsychotics.

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