Research on Frequency Selection of Triple Frequency in Earth Capacitance Measurement

energyo ◽  
2019 ◽  
Author(s):  
Qiukuan Zhou ◽  
Jun Yao ◽  
Yan Liu ◽  
Yi Tan ◽  
Yang Zou ◽  
...  
Keyword(s):  
Capacitance Measurement ◽  
Frequency Selection ◽  
Triple Frequency ◽  
Selection Of

Research on Frequency Selection of Triple Frequency in Earth Capacitance Measurement

2017 ◽  
Vol 18 (3) ◽  
Author(s):  
Qiukuan Zhou ◽  
Jun Yao ◽  
Yan Liu ◽  
Yi Tan ◽  
Yang Zou ◽  
...  
Keyword(s):  
Distribution Network ◽  
Selection Method ◽  
Capacitance Measurement ◽  
Distributed Network ◽  
Frequency Method ◽  
Voltage Transformer ◽  
Frequency Selection ◽  
Triple Frequency ◽  
Zero Sequence ◽  
Measurement Principle

AbstractThis paper investigates a frequency selection method of triple frequency in earth capacitance measurement. Based on the researches about the triple frequency method, the measurement principle of the proposed method is presented in detail. In this paper, the accurate earth capacitance in the distribution network can be calculated by establishing corresponding equations with injecting three different frequencies of current signals to the triangle open-side of voltage transformer (VT). Furthermore, the influences of selected frequency on the calculated results of the capacitive current are further analyzed. In order to improve the measurement accuracy, the initial selected frequencies of injected zero-sequence current signal should be set small as the larger earth capacitance in the distributed network is more common. Then the value of selected frequency should be increased correspondingly with the small capacitance in the distribution network. Finally, the correctness of theoretical analysis and feasibility of frequency selection method are verified with the simulation and experimental results of the earth capacitance measurement in distribution network.

A Skywave OTHR Adaptive Frequency Selection Method Based on Preliminary Criterion and Weighted Criterion

2014 ◽  
Vol 1061-1062 ◽  
pp. 974-977
Author(s):  
Shi Hua Liu ◽  
Xian Gang Liu ◽  
Zhi Jian Sun
Keyword(s):  
Selection Criterion ◽  
Selection Method ◽  
Frequency Selection ◽  
Selection Of

A skywave radar adaptive frequency selection method based on the preliminary criterion and the weighted criterion is presented. In this method, according to the various operational tasks, the frequency selection criterion is divided into the preliminary criterion and the weighted criterion based on the characteristic of the targets. The adaptive frequency selection of the skywave radar is achieved by the weighted computed of the frequency selection criterion. The feasibility and availability is demonstrated by an example.

scholarly journals An Electrochemical Chip to Monitor In Vitro Glycation of Proteins and Screening of Antiglycation Potential of Drugs

Pharmaceutics ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 1011
Author(s):  
Zeeshan A. Khan ◽  
Seungkyung Park
Keyword(s):  
Inhibitory Concentration ◽  
Strong Relationship ◽  
Protein Glycation ◽  
Capacitance Measurement ◽  
Efficacy Evaluation ◽  
Chronic Complications ◽  
Glycation End Products ◽  
Significant Change ◽  
Selection Of

Hyperglycemia and the production of advanced glycation end products (AGEs) are the primary factors for the development of chronic complications in diabetes. The level of protein glycation is proportional to the glucose concentration and represents mean glycemia. In this study, we present an electrochemical chip-based method for in vitro glycation monitoring and the efficacy evaluation of an antiglycation compound. An electrochemical chip consisting of five microchambers and embedded microelectrodes was designed for parallel measurements of capacitance signals from multiple solutions at different concentrations. The feasibility of glycation monitoring was then investigated by measuring the capacitance signal at 0.13 MHz with bovine serum albumin and gelatin samples in the presence of various glucose concentrations over 28 days. A significant change in the capacitance due to protein glycation was observed through measurements conducted within 30 s and 21 days of incubation. Finally, we demonstrated that the chip-based capacitance measurement can be utilized for the selection of an antiglycation compound by supplementing the protein solution and hyperglycemic concentration of glucose with an inhibitory concentration of the standard antiglycation agent aspirin. The lack of a significant change in the capacitance over 28 days proved that aspirin is capable of inhibiting protein glycation. Thus, a strong relationship exists between glycation and capacitance, suggesting the application of an electrochemical chip for evaluating glycation and novel antiglycation agents.

scholarly journals Distinct fast and slow processes contribute to the selection of preferred step frequency during human walking

2011 ◽  
Vol 110 (6) ◽  
pp. 1682-1690 ◽  
Author(s):  
Mark Snaterse ◽  
Robert Ton ◽  
Arthur D. Kuo ◽  
J. Maxwell Donelan
Keyword(s):  
Energy Expenditure ◽  
Closed Loop ◽  
Walking Speed ◽  
Prior Experience ◽  
Step Frequency ◽  
Total Change ◽  
Direct Optimization ◽  
Frequency Selection ◽  
Fine Tune ◽  
Selection Of

Humans spontaneously select a step frequency that minimizes the energy expenditure of walking. This selection might be embedded within the neural circuits that generate gait so that the optimum is pre-programmed for a given walking speed. Or perhaps step frequency is directly optimized, based on sensed feedback of energy expenditure. Direct optimization is expected to be slow due to the compounded effect of delays and iteration, whereas a pre-programmed mechanism presumably allows for faster step frequency selection, albeit dependent on prior experience. To test for both pre-programmed selection and direct optimization, we applied perturbations to treadmill walking to elicit transient changes in step frequency. We found that human step frequency adjustments ( n = 7) occurred with two components, the first dominating the response (66 ± 10% of total amplitude change; mean ± SD) and occurring quite quickly (1.44 ± 1.14 s to complete 95% of total change). The other component was of smaller amplitude (35 ± 10% of total change) and took tens of seconds (27.56 ± 16.18 s for 95% completion). The fast process appeared to be too fast for direct optimization and more indicative of a pre-programmed response. It also persisted even with unusual closed-loop perturbations that conflicted with prior experience and rendered the response energetically suboptimal. The slow process was more consistent with the timing expected for direct optimization. Our interpretation of these results is that humans may rely heavily on pre-programmed gaits to rapidly select their preferred step frequency and then gradually fine-tune that selection with direct optimization.

scholarly journals Simulation of an Adaptive Method of Improving the Accuracy and Extending the Range of Frequency Signal Processing in a Frequency-to-Code Converter

2021 ◽  
Vol 11 (21) ◽  
pp. 10341
Author(s):  
Piotr Warda
Keyword(s):  
Signal Processing ◽  
Adaptive Method ◽  
Variable Frequency ◽  
Frequency Change ◽  
Clock Signal ◽  
Frequency Signal ◽  
Frequency Selection ◽  
Processing Error ◽  
Simulation Results ◽  
Selection Of

The article discusses the modification of one of the basic methods of converting successive periods of a variable frequency signal into numerical values representing them. The method performs the adaptive frequency selection of the clock signal in the system processing the consecutive periods of input signal. The signal processing error is analyzed on an ongoing basis, and the frequency change factor is selected. Algorithms describing the operation of the method are included. The program of the simulator of the measurement channel operation with a frequency carrier of information is described, which allows for the verification of the proposed method. Examples of the simulation results are included.

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