scholarly journals Functioning conditions of the Casale pumping station in Mantova, Italy

2014 ◽  
Vol 7 (1) ◽  
pp. 151-168
Author(s):  
C. Capponi ◽  
M. Ferrante ◽  
M. Pedroni ◽  
B. Brunone ◽  
S. Meniconi ◽  
...  
Keyword(s):  
Rotation Speed ◽  
Variable Speed ◽  
Pumping Station ◽  
Polynomial Curves ◽  
Model Based ◽  
Cubic Polynomial ◽  
The Relationship ◽  
Analyze Data

Abstract. This paper aims to analyze data provided by TeaAcque for Casale pumping station in Mantova, Italy. A~model based on the affinity laws is used to simulate the behavior of the Casale pumping station where variable speed pumps (VSPs) are installed. Quadratic and cubic polynomial curves are used to fit the pump data given by the affinity laws. Such curves can be used to predict the efficiency when the functioning conditions change. The relationship between the variation in the rotation speed and the efficiency is also derived.

scholarly journals Functioning conditions of the Casale pumping station in Mantova, Italy

2014 ◽  
Vol 7 (2) ◽  
pp. 93-97 ◽  
Author(s):  
C. Capponi ◽  
M. Ferrante ◽  
M. Pedroni ◽  
B. Brunone ◽  
S. Meniconi ◽  
...  
Keyword(s):  
Rotation Speed ◽  
Input Power ◽  
Variable Speed ◽  
Discharge Data ◽  
Pump Speed ◽  
Pumping Station ◽  
Polynomial Curves ◽  
Model Based ◽  
Cubic Polynomial ◽  
The Relationship

Abstract. Pump speed, input power, pressure and discharge data are analyzed for evaluating functioning conditions of Casale pumping station in Mantova, Italy, managed by TeaAcque. A model based on the affinity laws is used to simulate the behavior of the installed variable speed pumps. Quadratic and cubic polynomial curves are used to fit the pump data given by the affinity laws. Such curves allow predicting the efficiency when the functioning conditions change. The relationship between the rotation speed and the efficiency is also derived.

scholarly journals Nonlinear Compound Control for Nonsinusoidal Vibration of the Mold Driven by Servo Motor with Variable Speed

2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
Qiang Li ◽  
Yi-ming Fang ◽  
Jian-xiong Li ◽  
Zhuang Ma
Keyword(s):  
Control Method ◽  
Controller Design ◽  
Rotation Speed ◽  
Pi Control ◽  
Variable Speed ◽  
Servo Motor ◽  
Motor Speed ◽  
Vector Method ◽  
Compound Control ◽  
The Relationship

In this paper, a fuzzy PI control method based on nonlinear feedforward compensation is proposed for the nonsinusoidal vibration system of mold driven by servo motor, rotated in single direction with variable speed. During controller design, there are mainly two issues to consider: (i) nonlinear relationship (approximate periodic function) between mold displacement and servo motor speed and (ii) uncertainties caused by backlash due to motor variable speed. So, firstly, the relationship between mold displacement and motor rotation speed is built directly based on the rotation vector method. Then, an observer is designed to estimate the uncertainties and feedforward compensation. Secondly, as the motor rotates in single direction with variable speed, a fuzzy control with bidirectional parameter adjustment is adopted to improve rapidity and stability based on the traditional PI method. Finally, some simulation results show the effectiveness of the proposed control method.

Pulse-Width Modulated Amplifier for DC Servo System and Its Matlab Simulation

2015 ◽  
Vol 9 (1) ◽  
pp. 625-631
Author(s):  
Ma Xiaocheng ◽  
Zhang Haotian ◽  
Cheng Yiqing ◽  
Zhu Lina ◽  
Wu Dan
Keyword(s):  
Mathematical Model ◽  
Transfer Function ◽  
Input Signal ◽  
Pulse Width ◽  
Rotation Speed ◽  
Servo Motor ◽  
Matlab Simulation ◽  
Pulse Width Modulated ◽  
Signal Changes ◽  
The Relationship

This paper introduces a mathematical model for Pulse-Width Modulated Amplifier for DC Servo Motor. The relationship between pulse-width modulated (PWM) signal and reference rotation speed is specified, and a general model of motor represented by transfer function is also put forward. When the input signal changes, the rotation speed of the servo motor will change accordingly. By changing zeros and poles, transient performance of this system is discussed in detail, and optimal ranges of the parameters is recommended at the end of discussion.

A new underwater positioning model based on average sound speed

2021 ◽  
pp. 1-17
Author(s):  
Yixu Liu ◽  
Xiushan Lu ◽  
Shuqiang Xue ◽  
Shengli Wang
Keyword(s):  
Efficient Algorithm ◽  
Sound Speed ◽  
Incident Angle ◽  
Function Model ◽  
Positioning Accuracy ◽  
Correction Model ◽  
Model Based ◽  
Underwater Positioning ◽  
Speed Function ◽  
The Relationship

Abstract The layout of seafloor datum points is the key to constructing the seafloor geodetic datum network, and a reliable underwater positioning model is the prerequisite for achieving precise deployment of the datum points. The traditional average sound speed positioning model is generally adopted in underwater positioning due to its simple and efficient algorithm, but it is sensitive to incident angle related errors, which lead to unreliable positioning results. Based on the relationship between incident angle and sound speed, the sound speed function model considering the incident angle has been established. Results show that the accuracy of positioning is easily affected by errors related to the incident angle; the new average sound speed correction model based on the incident angle proposed in this paper is used to significantly improve the underwater positioning accuracy.

Competing Explanations of Split-ticket Voting in American National Elections

2000 ◽  
Vol 28 (3) ◽  
pp. 379-407 ◽  
Author(s):  
FRANCO MATTEI ◽  
JOHN S. HOWES
Keyword(s):  
Small Group ◽  
National Elections ◽  
Congressional Voting ◽  
Party Polarization ◽  
Model Based ◽  
Alternative Approach ◽  
Candidate Evaluations ◽  
Electoral Expectations ◽  
The Relationship

In this article, the authors propose an extension to Fiorina's balancing model based on voters' electoral expectations and test this extension and several implications of the theory. The authors examine the observed pattern of ticket-splitting and find it less consistent with a balancing perspective than with an alternative approach stressing separation between presidential and congressional voting. They also address the relationship between party polarization and ticket-splitting; their results indicate that the occurrence of split ballots does not increase with polarization. A further test identifies respondents with both the sophistication and the motive to engage in balancing behavior. According to this analysis, balancing considerations influence, at most, the very small group of voters whose sophistication and electoral expectations give them the tools and the incentive to pursue balance with a split ballot. Ticket-splitting appears to result far more from incumbency and cross-pressured voters holding candidate evaluations at odds with their partisan learnings.

Research on the Attenuation Law of Stress Wave Propagation in Concrete Media

2013 ◽  
Vol 671-674 ◽  
pp. 758-767
Author(s):  
Wei Sun ◽  
Shi Yan ◽  
Shao Fei Jiang
Keyword(s):  
Wave Propagation ◽  
Attenuation Coefficient ◽  
Polynomial Function ◽  
Piezoelectric Ceramics ◽  
Stress Waves ◽  
Stress Wave Propagation ◽  
Research Results ◽  
Cubic Polynomial ◽  
The Relationship ◽  
Main Factor

This paper presents an experimental method to investigate the attenuation performance of stress waves in concrete structures embedded in piezoelectric ceramics. To get the research objective, a series of test were hold. The relationship curve between the frequency and the attenuation coefficient was fit. The calculation method for propagation distances of stress waves with constant amplitudes and frequencies in the concrete medium was proposed. The research results show that the relationship curve of attenuation coefficient and frequency conform to the cubic polynomial function approximately. The attenuation performance for the concrete structure embedded into piezoelectric ceramics is relevant to the frequency, the amplitude and the medium character, and the frequency is the main factor. The research results of this paper can provide an effective evidence for correctly placing transducers.

Substance Use and Self-Harm: Case Studies From Patients Admitted to an Urban Hospital Following Medically Serious Self-Harm

2017 ◽  
Vol 27 (14) ◽  
pp. 2201-2210 ◽  
Author(s):  
Elsie Breet ◽  
Jason Bantjes
Keyword(s):  
Substance Use ◽  
Case Study Research ◽  
Urban Hospital ◽  
Adaptive Function ◽  
The Past ◽  
Multiple Case ◽  
Self Harm ◽  
The Relationship ◽  
Analyze Data

Few qualitative studies have explored the relationship between substance use and self-harm. We employed a multiple-case study research design to analyze data from 80 patients who were admitted to a hospital in South Africa following self-harm. Our analysis revealed, from the perspective of patients, a number of distinct ways in which substance use is implicated in self-harm. Some patients reported that substance intoxication resulted in poor decision making and impulsivity, which led to self-harm. Others said substance use facilitated their self-harm. Some participants detailed how in the past their chronic substance use had served an adaptive function helping them to cope with distress, but more recently, this coping mechanism had failed which precipitated their self-harm. Some participants reported that substance use by someone else triggered their self-harm. Findings suggest that there are multiple pathways and a host of variables which mediate the relationship between substance use and self-harm.

scholarly journals Study on Sludge and Dissolved Oxygen Distribution in a Full-Scale A2/O Oxidation Ditch

Water ◽  
2021 ◽  
Vol 13 (19) ◽  
pp. 2776
Author(s):  
Chengyi Li ◽  
Zhao Han ◽  
Yuquan Zhang ◽  
Yuan Zheng ◽  
Hepeng Zhang ◽  
...  
Keyword(s):  
Dissolved Oxygen ◽  
Flow Model ◽  
Rotation Speed ◽  
Full Scale ◽  
Oxidation Ditch ◽  
Bed Height ◽  
Consumption Rates ◽  
The Relationship ◽  
Oxygenation Rate ◽  
Biological Selection

The distribution of velocity, sludge, and dissolved oxygen in a full-scale anaerobic-anoxic-oxic (A2/O) oxidation ditch was numerically simulated under three rotation speed scenarios. The viscosity and settling rate of activated sludge were defined through a user-defined function (UDF), and the sludge phase was calculated using the mixture multiphase flow model. Dissolved oxygen (DO) was set as a user-defined source (UDS) and its generation and consumption rates were defined with UDFs. The relationship between velocity and sludge concentration was found to be contradictory, with dead zones leading to large sludge concentrations at the bottom of the oxidation ditch (OD), but not at the middle-curved wall of the anoxic pool. The flow rate of the reflux slot and aerator oxygenation rate were checked and correlated with DO concentrations in the anaerobic pool. The majority of the large sludge concentrations were concentrated in the biological selection pool and these remained constant with bed height. With reduced propeller and agitator rotation speed, the sludge concentrations reduced in the biological selection pool, but increased in the anaerobic and anoxic pools.

scholarly journals Towards functional modelling of relationships between the acoustics and perception of vowels

2005 ◽  
Vol 40 ◽  
pp. 133-144
Author(s):  
Hartmut R. Pfitzinger
Keyword(s):  
Steady State ◽  
Sufficient Accuracy ◽  
Acoustic Properties ◽  
Vowel Quality ◽  
Model Based ◽  
Functional Modelling ◽  
The Relationship ◽  
Vowel Height

This paper summarizes our research efforts in functional modelling of the relationship between the acoustic properties of vowels and perceived vowel quality. Our model is trained on 164 short steady-state stimuli. We measured F1, F2, and additionally F0 since the effect of F0 on perceptual vowel height is evident. 40 phonetically skilled subjects judged vowel quality using the Cardinal Vowel diagram. The main focus is on refining the model and describing its transformation properties between the F1/F2 formant chart and the Cardinal Vowel diagram. An evaluation of the model based on 48 additional vowels showed the generalizability of the model and confirmed that it predicts perceived vowel quality with sufficient accuracy.  

scholarly journals Blade Tip-timing Technology with Multiple Reference Phases for Online Monitoring of High-speed Blades under Variable-speed Operation

2018 ◽  
Vol 18 (6) ◽  
pp. 243-250 ◽  
Author(s):  
Zhang Ji-wang ◽  
Zhang Lai-bin ◽  
Ding Ke-Qin ◽  
Duan Li-xiang
Keyword(s):  
High Speed ◽  
Online Monitoring ◽  
Rotation Speed ◽  
Experimental Tests ◽  
Reference Points ◽  
Variable Speed ◽  
Rotating Shaft ◽  
Virtual Reference ◽  
Blade Tip ◽  
Multiple Reference

Abstract High-speed blades form core mechanical components in turbomachines. Research concerning online monitoring of operating states of such blades has drawn increased attention in recent years. To this end, various methods have been devised, of which, the blade tip-timing (BTT) technique is considered the most promising. However, the traditional BTT method is only suitable for constant-speed operations. But in practice, the rotational speed of turbomachine blades is constantly changing under the influence of external factors, which lead to unacceptable errors in measurement. To tackle this problem, a new BTT method based on multi-phases is proposed. A plurality of phases was arranged as evenly as possible on the rotating shaft to determine the rotation speed. Meanwhile, the corresponding virtual reference point was determined in accordance with the number of blades between consecutive phases. Based on these reference points, equations to measure displacement due to blade vibrations were deduced. Finally, mathematical modeling, numerical simulation and experimental tests were performed to verify the validity of the proposed method. Results demonstrate that the error in measurement induced when using the proposed method is less than 1.8 %, which is much lower compared to traditional methods utilized under variable-speed operation.

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