Lumped-Parameter Response Time Models for Pneumatic Circuit Dynamics

2020 ◽  
Vol 143 (5) ◽  
Author(s):  
Andrew A. Stanley ◽  
Amirhossein Amini ◽  
Casey Glick ◽  
Nathan Usevitch ◽  
Yiğit Mengüç ◽  
...  
Keyword(s):  
Response Time ◽  
High Speed ◽  
Response Times ◽  
Coefficient Of Determination ◽  
Response Time Models ◽  
Response Curves ◽  
Flow Restriction ◽  
Lumped Parameter ◽  
Fluidic Circuits ◽  
Timing Models

Abstract Resistor–capacitor (RC) response time models for pressurizing and depressurizing a pneumatic capacitor (mass accumulator) through a resistor (flow restriction) comprise a framework to systematically analyze complex fluidic circuits. A model for pneumatic resistance is derived from a combination of fundamental fluid mechanics and experimental results. Models describing compressible fluid capacitance are derived from thermodynamic first principles and validated experimentally. The models are combined to derive the ordinary differential equations that describe the RC dynamics. These equations are solved analytically for rigid capacitors and numerically for deformable capacitors to generate pressure response curves as a function of time. The dynamic pressurization and depressurization response times to reach 63.2% (or 1−e−1) of exponential decay are validated in simple pneumatic circuits with combinations of flow restrictions ranging from 100 μm to 1 mm in diameter, source pressures ranging from 5 to 200 kPa, and capacitor volumes of 0.5 to 16 mL. Our RC models predict the response times, which range from a few milliseconds to multiple seconds depending on the combination, with a coefficient of determination of r2=0.983. The utility of the models is demonstrated in a multicomponent fluidic circuit to find the optimal diameter of tubing between a three-way electromechanical valve and a pneumatic capacitor to minimize the response time for the changing pressure in the capacitor. These lumped-parameter models represent foundational blocks upon which timing models of pneumatic circuits can be built for a variety of applications from soft robotics and industrial automation to high-speed microfluidics.

Integrated Piezoelectric Linear Motor for Vehicle Applications

2002 ◽  
Author(s):  
Mark Vaughan ◽  
Donald J. Leo
Keyword(s):  
Motor Performance ◽  
High Speed ◽  
Response Times ◽  
Fast Response ◽  
Linear Motor ◽  
Lumped Parameter Model ◽  
Moving Loads ◽  
Drive Frequency ◽  
Lumped Parameter ◽  
Motor Design

The focus of this research was to create a linear motor that could easily be packaged and still perform the same task of the current DC motor linear device. An incremental linear motor design was decided upon, for its flexibility in which the motor can be designed. To replace the current motor it was necessary to develop a high force, high speed incremental linear motor. To accomplish this task, piezoelectric actuators were utilized to drive the motor due their fast response times and high force capabilities. The desired overall objectives of the research is to create an incremental linear motor with the capability of moving loads up to one hundred pounds and produce a velocity well over one inch per second. To aid the design process a lumped parameter model was created to simulate the motor’s performance for any design parameter. Discrepancies occurred between the model and the actual motor performance for loads above 9.1 kilograms (20 pounds). The resulting model, however, was able to produce a good approximation of the motor’s performance for the unloaded and lightly loaded cases. The incremental linear motor produced a velocity of 4.9 mm/sec (0.2 in/sec) at a drive frequency of 50 Hz. The velocity of the motor was limited by the drive frequency that the amplifiers could produce. The motor was found to produce a stall load of 17 kilograms (38 pounds). The stall load of the design was severely limited by clearance losses.

Optimization of Electromagnetic Actuator Performance for High-Speed Valves

1986 ◽  
Vol 108 (3) ◽  
pp. 351-357
Author(s):  
J. P. Karidis ◽  
S. R. Turns
Keyword(s):  
Response Time ◽  
High Speed ◽  
Fuel Injection ◽  
Dynamic Performance ◽  
Optimization Technique ◽  
Control Valve ◽  
Design Parameters ◽  
Electromagnetic Actuators ◽  
Lumped Parameter ◽  
Injection Control

The dynamic performance of electromagnetic actuators driving on-off control valves is optimized numerically by combining hybrid lumped-parameter/distributed-parameter actuator models with an efficient constrained optimization technique. Two examples of constrained actuator optimization are presented where up to eight design parameters are optimized. One example problem involves minimizing variations in the response time of a fuel injection control valve caused by manufacturing and assembly tolerances, while the other example deals with minimizing the response time of a high-speed gas sampling valve.

scholarly journals Response time correction of slow response sensor data by deconvolution of the growth-law equation

2021 ◽  
Author(s):  
Knut Ola Dølven ◽  
Juha Vierinen ◽  
Roberto Grilli ◽  
Jack Triest ◽  
Bénédicte Ferré
Keyword(s):  
Response Time ◽  
Diffusion Processes ◽  
Membrane Separation ◽  
Response Times ◽  
Measurement Model ◽  
Sensor Data ◽  
Coefficient Of Determination ◽  
Measured Quantity ◽  
Slow Response ◽  
Time Step

Abstract. Accurate, high resolution measurements are essential to improve our understanding of environmental processes. Several chemical sensors relying on membrane separation extraction techniques have slow response times due to a dependence on equilibrium partitioning across the membrane separating the measured medium (i.e., a measuring chamber) and the medium of interest (i.e., a solvent). We present a new technique for deconvolving slow sensor response signals using statistical inverse theory; applying a weighted linear least squares estimator with the growth-law as measurement model. The solution is regularized using model sparsity, assuming changes in the measured quantity occurs with a certain time-step, which can be selected based on domain-specific knowledge or L-curve analysis. The advantage of this method is that it: 1) models error propagation, providing an explicit uncertainty estimate of the response time corrected signal, 2) enables evaluation of the solutions self consistency, and 3) only requires instrument accuracy, response time, and data as input parameters. Functionality of the technique is demonstrated using simulated, laboratory, and field measurements. In the field experiment, the coefficient of determination (R2) of a slow response methane sensor in comparison with an alternative, fast response sensor, significantly improved from 0.18 to 0.91 after signal deconvolution. This shows how the proposed method can open up a considerably wider set of applications for sensors and methods suffering from slow response times due to a reliance on the efficacy of diffusion processes.

Assessing Fit of the Lognormal Model for Response Times

2020 ◽  
Vol 45 (5) ◽  
pp. 534-568
Author(s):  
Sandip Sinharay ◽  
Peter W. van Rijn
Keyword(s):  
Factor Analysis ◽  
Response Time ◽  
Simulation Study ◽  
Response Times ◽  
Real Data ◽  
Psychological Testing ◽  
Response Time Models ◽  
Lognormal Model ◽  
Analysis Models

Response time models (RTMs) are of increasing interest in educational and psychological testing. This article focuses on the lognormal model for response times, which is one of the most popular RTMs. Several existing statistics for testing normality and the fit of factor analysis models are repurposed for testing the fit of the lognormal model. A simulation study and two real data examples demonstrate the usefulness of the statistics. The Shapiro–Wilk test of normality and a z-test for factor analysis models were the most powerful in assessing the misfit of the lognormal model.

scholarly journals Stimulus-response time to invasive blood pressure alarms: implications for the safety of critical-care patients

2014 ◽  
Vol 35 (2) ◽  
pp. 135-141 ◽  
Author(s):  
Adele Kuckartz Pergher ◽  
Roberto Carlos Lyra da Silva
Keyword(s):  
Blood Pressure ◽  
Response Time ◽  
Response Times ◽  
Hemodynamic Instability ◽  
Military Hospital ◽  
Invasive Blood Pressure ◽  
Stimulus Response ◽  
The City ◽  
Physical Layout

Observational, descriptive, exploratory, case study with the objective of measuring the stimulus-response time of the team to alarms monitoring invasive blood pressure (IBP) and analyzing the implications of this time for the safety of the patient. From January to March 2013, 60 hours of structured observation were conducted with registration of the alarms activated by IBP monitors in an adult ICU at a military hospital in the city of Rio de Janeiro. 76 IBP alarms were recorded (1.26 alarms/hour), 21 of which (28%) were attended to and 55 (72%) considered as fatigued. The average response time to the alarms was 2 min. 45 sec. The deficit in human resource and physical layout were factors determining the delay in response to the alarms. The increase in response times to these alarms may compromise the safety of patients with hemodynamic instability, especially in situations such as shock and the use of vasoactive drugs.

scholarly journals English Speakers’ Implicit Gender Concepts Influence Their Processing of French Grammatical Gender: Evidence for Semantically Mediated Cross-Linguistic Influence

2021 ◽  
Vol 12 ◽  
Author(s):  
Elena Nicoladis ◽  
Chris Westbury ◽  
Cassandra Foursha-Stevenson
Keyword(s):  
Second Language ◽  
Response Time ◽  
Response Times ◽  
First Language ◽  
Grammatical Gender ◽  
Word Embedding ◽  
English Speakers ◽  
French Words ◽  
L1 English ◽  
French Gender

Second language (L2) learners often show influence from their first language (L1) in all domains of language. This cross-linguistic influence could, in some cases, be mediated by semantics. The purpose of the present study was to test whether implicit English gender connotations affect L1 English speakers’ judgments of the L2 French gender of objects. We hypothesized that gender estimates derived from word embedding models that measure similarity of word contexts in English would affect accuracy and response time on grammatical gender (GG) decision in L2 French. L2 French learners were asked to identify the GG of French words estimated to be either congruent or incongruent with the implicit gender in English. The results showed that they were more accurate with words that were congruent with English gender connotations than words that were incongruent, suggesting that English gender connotations can influence grammatical judgments in French. Response times showed the same pattern. The results are consistent with semantics-mediated cross-linguistic influence.

scholarly journals Glacier volume response time and its links to climate and topography based on a conceptual model of glacier hypsometry

2009 ◽  
Vol 3 (1) ◽  
pp. 243-275 ◽  
Author(s):  
S. C. B. Raper ◽  
R. J. Braithwaite
Keyword(s):  
Response Time ◽  
Mass Balance ◽  
Conceptual Model ◽  
Response Times ◽  
Climate Modelling ◽  
Scaling Relation ◽  
Ablation Volume ◽  
Glacier Terminus ◽  
Volume Response ◽  
Simple Ratio

Abstract. Glacier volume response time is a measure of the time taken for a glacier to adjust its geometry to a climate change. It is currently believed that the volume response time is given approximately by the ratio of glacier thickness to ablation at the glacier terminus. We propose a new conceptual model of glacier hypsometry (area-altitude relation) and derive the volume response time where climatic and topographic parameters are separated. The former is expressed by mass balance gradients which we derive from glacier-climate modelling and the latter are quantified with data from the World Glacier Inventory. Aside from the well-known scaling relation between glacier volume and area, we establish a new scaling relation between glacier altitude range and area, and evaluate it for seven regions. The presence of this scaling parameter in our response time formula accounts for the mass balance elevation feedback and leads to longer response times than given by the simple ratio of glacier thickness to ablation. Volume response times range from decades to thousands of years for glaciers in maritime (wet-warm) and continental (dry-cold) climates, respectively. The combined effect of volume-area and altitude-area scaling relations is such that volume response time can increase with glacier area (Axel Heiberg Island and Svalbard), hardly change (Northern Scandinavia, Southern Norway and the Alps) or even get smaller (The Caucasus and New Zealand).

scholarly journals A High-Stakes Approach to Response Time Effort in Low-Stakes Assessment

2021 ◽  
Vol 7 (4) ◽  
pp. 571-586
Author(s):  
Munevver Ilgun
Keyword(s):  
Response Time ◽  
Failure Time ◽  
Response Times ◽  
Survival Models ◽  
Accelerated Failure Time ◽  
Data Sets ◽  
High Stakes ◽  
Problem Solving Skills ◽  
Educational Stakeholders ◽  
Accelerated Failure Time Models

<p style="text-align: justify;">Response times are one of the important sources that provide information about the performance of individuals during a test process. The main purpose of this study is to show that survival models can be used in educational data. Accordingly, data sets of items measuring literacy, numeracy and problem-solving skills of the countries participating in Round 3 of the Programme for the International Assessment of Adult Competencies were used. Accelerated failure time models have been analyzed for each country and domain.  As a result of the analysis of the models in which various covariates are included as independent variables, and response time for giving correct answers is included as a dependent variable, it was found the associations between the covariates and response time for giving correct answers were concluded to vary from one domain to another or from one country to another. The results obtained from the present study have provided the educational stakeholders and practitioners with valuable information.</p>

scholarly journals Estimation of aerator air demand by an embedded multi-gene genetic programming

2021 ◽  
Author(s):  
Shicheng Li ◽  
James Yang ◽  
Wei Liu
Keyword(s):  
Genetic Programming ◽  
High Speed ◽  
Pareto Front ◽  
Gene Expression Programming ◽  
Absolute Error ◽  
Processing Technique ◽  
Coefficient Of Determination ◽  
Speed Flow ◽  
Processing Measure ◽  
Programming Solution

Abstract A spillway discharging a high-speed flow is susceptible to cavitation damages. As a countermeasure, an aerator is often used to artificially entrain air into the flow. Its air demand is of relevance to cavitation reduction and requires accurate estimations. The main contribution of this study is to establish an embedded multi-gene genetic programming (EMGGP) model for improved prediction of air demand. It is an MGGP-based framework coupled with the gene expression programming acting as a pre-processing technique for input determination and the Pareto front serving as a post-processing measure for solution optimization. Experimental data from a spillway aerator are used to develop and validate the proposed technique. Its performance is statistically evaluated by the coefficient of determination (CD), Nash–Sutcliffe coefficient (NSC), root-mean-square error (RMSE) and mean absolute error (MAE). Satisfactory predictions are yielded with CD = 0.95, NSC = 0.94, RMSE = 0.17 m3/s and MAE = 0.12 m3/s. Compared with the best empirical formula, the EMGGP approach enhances the fitness (CD and NSC) by 23% and reduces the errors (RMSE and MAE) by 48%. It also exhibits higher prediction accuracy and a simpler expressional form than the genetic programming solution. This study provides a procedure for the establishment of parameter relationships for similar hydraulic issues.

scholarly journals Response Time Distribution Analysis of Semantic and Response Interference in a Manual Response Stroop Task

2019 ◽  
Vol 66 (3) ◽  
pp. 231-238 ◽  
Author(s):  
Nabil Hasshim ◽  
Michelle Downes ◽  
Sarah Bate ◽  
Benjamin A. Parris
Keyword(s):  
Response Time ◽  
Stroop Task ◽  
Time Distribution ◽  
Response Times ◽  
Response Time Distribution ◽  
Stroop Interference ◽  
Response Conflict ◽  
Distribution Analysis ◽  
Manual Response ◽  
Response Interference

Abstract. Previous analyses of response time distributions have shown that the Stroop effect is observed in the mode (μ) and standard deviation (σ) of the normal part of the distribution, as well as its tail (τ). Specifically, interference related to semantic and response processes has been suggested to specifically affect the mode and tail, respectively. However, only one study in the literature has directly manipulated semantic interference, and none manipulating response interference. The present research aims to address this gap by manipulating both semantic and response interference in a manual response Stroop task, and examining how these components of Stroop interference affect the response time distribution. Ex-Gaussian analysis showed both semantic and response conflict to only affect τ. Analyzing the distribution by rank-ordered response times (Vincentizing) showed converging results as the magnitude of both semantic and response conflict increased with slower response times. Additionally, response conflict appeared earlier on the distribution compared to semantic conflict. These findings further highlight the difficulty in attributing specific psychological processes to different parameters (i.e., μ, σ, and τ). The effect of different response modalities on the makeup of Stroop interference is also discussed.

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