Research on Speed Changing Curve of Servo Turret Motor

2012 ◽  
Vol 198-199 ◽  
pp. 137-140
Author(s):  
Yu Sheng Wang ◽  
Ming Ming Wang ◽  
Xiang Jun Zhu
Keyword(s):  
Mechanical System ◽  
High Reliability ◽  
High Accuracy ◽  
Servo Motor ◽  
Motor Speed ◽  
Mechanical Structure ◽  
Fast Speed ◽  
Acceleration And Deceleration ◽  
Critical Problems ◽  
The Impact

Because of such merits of servo turret like fast speed of tool changing, high accuracy of first location, simple mechanical structure, high reliability and so on, servo turrets are widely used in turning processing and turning and milling complex processing center.Control mode of servo motor speed is one of the critical problems in the designing of servo turret.S curve acceleration and deceleration control is to make the derivative of acceleration as constant in this procession, and maximize to reduce the impact of mechanical system by controlling acceleration derivative. Otherwise, by setting parameter or programming acceleration and its derivative, flexible acceleration and deceleration will be controlled to fit for different kinds of situation of machines.

scholarly journals HOW DO LEARNING DISORDERS IMPACT CLINICAL MEASURES FOLLOWING CONCUSSION?

2020 ◽  
Vol 8 (4_suppl3) ◽  
pp. 2325967120S0018
Author(s):  
Aaron J. Zynda ◽  
Mathew A. Stokes ◽  
Jane S. Chung ◽  
C. Munro Cullum ◽  
Shane M. Miller
Keyword(s):  
Symptom Score ◽  
Learning Disorders ◽  
Total Symptom Score ◽  
Adhd Group ◽  
Motor Speed ◽  
The North ◽  
History Of ◽  
Visual Motor ◽  
Clinical Measures ◽  
The Impact

Background: There is limited evidence examining the impact of learning disorders on testing and screening scores used in evaluation following concussion in adolescents. Purpose: To examine differences in clinical measures between adolescents with a history of dyslexia or ADD/ADHD and those without a history of learning disorder (LD) following concussion. Methods: Data were collected from participants enrolled in the North Texas Concussion Network Prospective Registry (ConTex). Participants ages 10-18 who had been diagnosed with a concussion sustained within 30 days of enrollment were included. Participants were separated into three groups based on self-reported prior diagnosis: dyslexia, ADD/ADHD, and no history of LD. Clinical measures from initial presentation were examined, including ImPACT®, King-Devick (KD), SCAT-5 symptom log, Patient Health Questionnaire (PHQ-8), and Generalized Anxiety Disorder (GAD-7) scale. Independent t-test analysis was performed to compare scores between groups. Results: A total of 993 participants were included; 68 with dyslexia, 141 with ADD/ADHD, and 784 with no history of LD. There was no difference in age, sex, time since injury, or history of concussion between the dyslexia group and no LD group. In the ADD/ADHD group, there were significantly more male participants (64.5% and 50.3% respectively, p=0.002). Participants with a history of dyslexia had a significant increase in KD time (63.7 sec vs 56.5 sec, p=0.019). Additionally, ImPACT® testing showed a decrease in visual motor speed (28.87 vs 32.99, p= 0.010). Total symptom score was higher in this group as well (36.22 vs 28.27, p=0.013). In those with a history of ADD/ADHD, multiple domains were found to be significantly different on ImPACT® testing including visual motor speed (30.05), reaction time (0.75), and cognitive efficiency (0.23) when compared to those with no LD (32.99, 0.71, and 0.27 respectively, p=0.004, 0.047, 0.027). KD time was also significantly higher in this group (62.1 sec vs 56.5 sec, p=0.008), as was the total symptom score (32.99 vs 28.27, p=0.043). PHQ-8 and GAD-7 were both significantly higher in the group with ADD/ADHD (5.79 and 5.06 respectively, p=0.001) than those with no LD (4.32 and 3.56, p=0.001). Conclusion: Differences were seen in participants with a history of dyslexia and ADD/ADHD on clinical concussion measures, including ImPACT® and KD testing, SCAT-5 symptom log, and screenings for depression and anxiety. A better understanding of the unique profiles seen in these patients will aid providers in their evaluation and assist as they counsel families regarding their child’s injury.

scholarly journals Code Calibration of the Eurocodes

2021 ◽  
Vol 11 (12) ◽  
pp. 5474
Author(s):  
Tuomo Poutanen
Keyword(s):  
High Reliability ◽  
High Accuracy ◽  
Variable Load ◽  
Reliability Model ◽  
Safety Factors ◽  
Rounding Errors ◽  
Code Calibration ◽  
Load Factors ◽  
Characteristic Values

This article addresses the process to optimally select safety factors and characteristic values for the Eurocodes. Five amendments to the present codes are proposed: (1) The load factors are fixed, γG = γQ, by making the characteristic load of the variable load changeable, it simplifies the codes and lessens the calculation work. (2) Currently, the characteristic load of the variable load is the same for all variable loads. It creates excess safety and material waste for the variable loads with low variation. This deficiency can be avoided by applying the same amendment as above. (3) Various materials fit with different accuracy in the reliability model. This article explains two options to reduce this difficulty. (4) A method to avoid rounding errors in the safety factors is explained. (5) The current safety factors are usually set by minimizing the reliability indexes regarding the target when the obtained codes include considerable safe and unsafe design cases with the variability ratio (high reliability/low) of about 1.4. The proposed three code models match the target β50 = 3.2 with high accuracy, no unsafe design cases and insignificant safe design cases with the variability ratio 1.07, 1.03 and 1.04.

scholarly journals Crisis Management in Higher Education in the Time of Covid-19: The Case of Actor Training

2021 ◽  
Vol 11 (3) ◽  
pp. 132
Author(s):  
Anna McNamara
Keyword(s):  
Higher Education ◽  
Crisis Management ◽  
High Frequency ◽  
High Reliability ◽  
Actor Training ◽  
Management Actions ◽  
The Usa ◽  
The Uk ◽  
The Impact ◽  
High Frequency Words

The impact of Covid-19 placed Higher Education leadership in a state of crisis management, where decision making had to be swift and impactful. This research draws on ethea of mindfulness, actor training techniques, referencing high-reliability organisations (HRO). Interviews conducted by the author with three leaders of actor training conservatoires in Higher Education institutions in Australia, the UK and the USA reflect on crisis management actions taken in response to the impact of Covid-19 on their sector, from which high-frequency words are identified and grouped thematically. Reflecting on these high-frequency words and the thematic grouping, a model of mindful leadership is proposed as a positive tool that may enable those in leadership to recognise and respond efficiently to wider structural frailties within Higher Education, with reference to the capacity of leaders to operate with increased mindfulness, enabling a more resilient organisation that unlocks the locus of control.

scholarly journals Research on an Improved Sliding Mode Sensorless Six-Phase PMSM Control Strategy Based on ESO

Electronics ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 1292
Author(s):  
Hanying Gao ◽  
Guoqiang Zhang ◽  
Wenxue Wang ◽  
Xuechen Liu
Keyword(s):  
Control System ◽  
Control Strategy ◽  
Sliding Mode ◽  
High Reliability ◽  
Permanent Magnet Synchronous Motor ◽  
Torque Ripple ◽  
Estimation Accuracy ◽  
Switching Function ◽  
Motor Speed ◽  
Rotor Position

The six-phase motor control system has low torque ripple, low harmonic content, and high reliability; therefore, it is suitable for electric vehicles, aerospace, and other applications requiring high power output and reliability. This study presents a superior sensorless control system for a six-phase permanent magnet synchronous motor (PMSM). The mathematical model of a PMSM in a stationary coordinate system is presented. The information of motor speed and position is obtained by using a sliding mode observer (SMO). As torque ripple and harmonic components affect the back electromotive force (BEMF) estimated value through the traditional SMO, the function of the frequency-variable tracker of the stator current (FVTSC) is used instead of the traditional switching function. By improving the SMO method, the BEMF is estimated independently, and its precision is maintained under startup or variable-speed states. In order to improve the estimation accuracy and resistance ability of the observer, the rotor position error was taken as the disturbance term, and the third-order extended state observer (ESO) was constructed to estimate the rotational speed and rotor position through the motor mechanical motion equation. Finally, the effectiveness of the method is verified by simulation and experiment results. The proposed control strategy can effectively improve the dynamic and static performance of PMSM.

Cognition predicts days-alive-out-of-hospital after LVAD implantation

2021 ◽  
pp. 039139882110184
Author(s):  
Marykay A Pavol ◽  
Amelia K Boehme ◽  
Melana Yuzefpolskaya ◽  
Mathew S Maurer ◽  
Jesus Casida ◽  
...  
Keyword(s):  
Linear Regression ◽  
Regression Model ◽  
Linear Regression Model ◽  
Left Ventricular ◽  
Motor Speed ◽  
Ventricular Assist ◽  
Hospitalization Rates ◽  
Left Ventricular Assist ◽  
Patient Groups ◽  
The Impact

Objective: Cognition influences hospitalization rates for a variety of patient groups but this association has not been examined in heart failure (HF) patients undergoing left ventricular assist device (LVAD) implantation. We used cognition to predict days-alive-out-of-hospital (DAOH) in patients after LVAD surgery. Methods: We retrospectively identified 59 HF patients with cognitive assessment prior to LVAD. Cognitive tests of attention, memory, language, and visual motor speed were averaged into one score. DAOH was converted to a percentage based on total days from LVAD surgery to either heart transplant or 900 days post-LVAD. Variables significantly associated with DAOH in univariate analyses were included in a linear regression model to predict DAOH. Results: A linear regression model including LVAD type (continuous or pulsatile flow) and cognition significantly predicted DAOH (F(2,54) = 6.44, p = 0.003, R2 = .19). Inspection of each variable revealed that cognition was a significant predictor in the model (β = .11, SE = .04, p = 0.007) but LVAD type was not ( p = 0.08). Conclusions: Cognitive performance assessed prior to LVAD implantation predicted how much time patients spent out of the hospital following surgery. Further studies are warranted to identify the impact of pre-LVAD cognition on post-LVAD hospitalization.

Development and validation of men's sexualizing behaviors of women scale

2017 ◽  
Author(s):  
◽  
Dominique A. Malebranche
Keyword(s):  
Factor Analysis ◽  
Task Force ◽  
High Reliability ◽  
Future Research ◽  
Sexual Objectification ◽  
Adult Males ◽  
Gender Based Violence ◽  
Task Force Report ◽  
Traditional Masculinity ◽  
The Impact

[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT AUTHOR'S REQUEST.] Sexualization has been posited to be a part of a larger process of socialization with negative implications (APA, 2010; Ward, 2016). Recent reviews of gender-based violence and exploitation have focused on important elements that highlight the impact of the pervasive experiences of sexual objectification and sexual commodification on women and girls, but relatively limited literature has explored domains of men's sexualizing behaviors. Using the theoretical domains outlined in the APA Task Force Report on the Sexualization of Girls (APA, 2010), the present study developed and validated a measure of men's sexualizing behaviors toward women (MSBWS) on a sample of 308 adult males (ages 18-34). Using exploratory factor analysis, results indicated three-factors that defined the MSBWS: Covert, Commodified, and Overt Sexualization. Analyses also revealed the MSBWS to have high reliability for the overall scale as well as the three subscales. Evidence for construct validity was revealed in significant correlations with all criterion variables (e.g., attitudes of sexual objectification, traditional masculinity and sexual aggression) and suggest broad implications that men's sexualizing behaviors is a measurable construct. Future research may further validate the MSBWS using confirmatory factor analysis on independent samples and examine relevant variables of the possible harm of sexualizing behaviors.

scholarly journals Performance analysis of the thermoacoustic refrigerator with the standing wave and air as a working fluid

2018 ◽  
Vol 44 ◽  
pp. 00063 ◽  
Author(s):  
Jakub Kajurek ◽  
Artur Rusowicz
Keyword(s):  
Temperature Difference ◽  
High Reliability ◽  
Power Input ◽  
Acoustic Power ◽  
Operating Frequency ◽  
Working Fluid ◽  
Resonator Length ◽  
Environmental Friendliness ◽  
The Impact ◽  
Thermoacoustic Refrigerator

Thermoacoustic refrigerator is a new and emerging technology capable of transporting heat from a low-temperature source to a high-temperature source by utilizing the acoustic power input. These devices, operating without hazardous refrigerants and owning no moving components, show advantages of high reliability and environmental friendliness. However, simple to fabricate, the designing of thermoacoustic refrigerators is very challenging. This paper illustrates the impact of significant factors on the performance of the thermoacoustic refrigerator which was measured in terms of the temperature difference generated across the stack ends. The experimental device driven by a commercial loudspeaker and air at atmospheric pressure as a working fluid was examined under various resonator length and operating frequencies. The results indicate that appropriate resonator’s length and operating frequency lead to an increase in the temperature difference created across the stack. The maximum values were achieved for operating frequency equalled to 200 and 300 Hz whereas resonator length corresponded to the half-length of the acoustic wave for these frequencies. The results of experiment also confirm that relationship between these parameters is strongly affected by the stack spacing, which in this research was equalled to 0.4 mm.

Use of Pulse Oximetry in Radiotherapy

2015 ◽  
Vol 1084 ◽  
pp. 515-518
Author(s):  
Nina I. Martemyanova ◽  
Natalia D. Turgunova ◽  
Aleksandr N. Aleinik
Keyword(s):  
Radiation Therapy ◽  
Pulse Oximeter ◽  
High Reliability ◽  
The Body ◽  
Good Resolution ◽  
Blood Oxygen ◽  
Blood Oxygen Saturation ◽  
Arterial Blood ◽  
Arterial Blood Oxygen ◽  
The Impact

Reflectance pulse oximeter is designed to determine arterial blood oxygen saturation during a radiation therapy. Proposed solutions promote to reduce the impact of sensor motion on the readings. Experimentally obtained optimal contact pressure of the sensor on the body is 0.7 N. The preliminary results show that the device has good resolution and high reliability.

Multi-Object Multi-Discipline Probabilistic Design of High-Pressure Turbine Blade-Tip Radial Running Clearance

2013 ◽  
Vol 572 ◽  
pp. 551-554
Author(s):  
Wen Zhong Tang ◽  
Cheng Wei Fei ◽  
Guang Chen Bai
Keyword(s):  
Mathematical Model ◽  
High Pressure ◽  
Optimal Design ◽  
Mechanical System ◽  
High Accuracy ◽  
Probabilistic Design ◽  
High Pressure Turbine ◽  
Surface Method ◽  
Blade Tip ◽  
The Mathematical Model

For the probabilistic design of high-pressure turbine (HPT) blade-tip radial running clearance (BTRRC), a distributed collaborative response surface method (DCRSM) was proposed, and the mathematical model of DCRSM was established. From the BTRRC probabilistic design based on DCRSM, the static clearance δ=1.865 mm is demonstrated to be optimal for the BTRRC design considering aeroengine reliability and efficiency. Meanwhile, DCRSM is proved to be of high accuracy and efficiency in the BTRRC probabilistic design. The present study offers an effective way for HPT BTRRC dynamic probabilistic design and provides also a promising method for the further probabilistic optimal design of complex mechanical system.

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