The effects of spaceflight on open-loop and closed-loop postural control mechanisms: human neurovestibular studies on SLS-2

1995 ◽  
Vol 107 (1) ◽  
pp. 145-150 ◽  
Author(s):  
J. J. Collins ◽  
C. J. De Luca ◽  
A. E. Pavlik ◽  
S. H. Roy ◽  
M. S. Emley
Keyword(s):  
Postural Control ◽  
Closed Loop ◽  
Open Loop ◽  
Control Mechanisms

Age-related changes in open-loop and closed-loop postural control mechanisms

1995 ◽  
Vol 104 (3) ◽  
pp. 480-492 ◽  
Author(s):  
J. J. Collins ◽  
C. J. De Luca ◽  
A. Burrows ◽  
L. A. Lipsitz
Keyword(s):  
Postural Control ◽  
Closed Loop ◽  
Open Loop ◽  
Control Mechanisms ◽  
Age Related ◽  
Age Related Changes

Acute Effects of a Single Bout of Resistance Exercise on Postural Control in Elderly Persons

2005 ◽  
Vol 100 (3) ◽  
pp. 725-733 ◽  
Author(s):  
Justin B. Moore ◽  
Thomas Korff ◽  
Stephen J. Kinzey
Keyword(s):  
Resistance Training ◽  
Postural Control ◽  
Resistance Exercise ◽  
Critical Point ◽  
Center Of Pressure ◽  
Open Loop ◽  
Elderly Persons ◽  
Control Mechanisms ◽  
Acute Effects ◽  
Loop Control

Many elderly persons are engaging in resistance exercise to counter muscle atrophy due to aging. Here, the acute effects of resistance exercise on postural control mechanisms were examined. Postural control was quantified by mean square center-of-pressure displacements were calculated utilizing force vectors in accordance with previously developed equations. Stabilogram-diffusion plots utilized the displacements as data points after curve-fitting techniques were applied. Two regions, representing the open-loop and closed-loop postural control mechanisms, are shown by the plots and separated at the critical point, which represents the shift in control mechanisms. 21 older adults (age M = 71.2, SD = 3.84, range 66–81 years) performed three sets of 10–12 repetitions for six resistance exercises for the lower extremity until fatigue. Immediately after exercise, postural stability was reduced. This was represented by a shift of the critical point to the right, indicating an increase in open-loop control. Since resistance training has an acute negative effect on postural control, it is advised to assist elderly clients carefully and immediately after resistance training.

scholarly journals Influences of Frailty Syndrome on Open-Loop and Closed-Loop Postural Control Strategy

Gerontology ◽  
2015 ◽  
Vol 61 (1) ◽  
pp. 51-60 ◽  
Author(s):  
Nima Toosizadeh ◽  
Jane Mohler ◽  
Christopher Wendel ◽  
Bijan Najafi
Keyword(s):  
Postural Control ◽  
Control Strategy ◽  
Closed Loop ◽  
Open Loop ◽  
Frailty Syndrome ◽  
Postural Control Strategy

On closed-loop equilibrium strategies for mean-field stochastic linear quadratic problems

2020 ◽  
Vol 26 ◽  
pp. 41
Author(s):  
Tianxiao Wang
Keyword(s):  
Optimal Control ◽  
Closed Loop ◽  
Optimal Control Problems ◽  
Mean Field ◽  
Open Loop ◽  
Time Inconsistency ◽  
Control Problems ◽  
Linear Quadratic ◽  
Linear Quadratic Optimal Control ◽  
Equilibrium Strategies

This article is concerned with linear quadratic optimal control problems of mean-field stochastic differential equations (MF-SDE) with deterministic coefficients. To treat the time inconsistency of the optimal control problems, linear closed-loop equilibrium strategies are introduced and characterized by variational approach. Our developed methodology drops the delicate convergence procedures in Yong [Trans. Amer. Math. Soc. 369 (2017) 5467–5523]. When the MF-SDE reduces to SDE, our Riccati system coincides with the analogue in Yong [Trans. Amer. Math. Soc. 369 (2017) 5467–5523]. However, these two systems are in general different from each other due to the conditional mean-field terms in the MF-SDE. Eventually, the comparisons with pre-committed optimal strategies, open-loop equilibrium strategies are given in details.

Comparison of Dc-Dc SEPIC, CUK and Flyback Converters Based LED Drivers

2020 ◽  
pp. 99-107
Author(s):  
Erdal Sehirli
Keyword(s):  
Integrated Circuit ◽  
Closed Loop ◽  
Input Voltage ◽  
Open Loop ◽  
Current Sensor ◽  
Switching Frequency ◽  
Led Driver ◽  
Advantages And Disadvantages ◽  
Led Drivers ◽  
Conduction Mode

This paper presents the comparison of LED driver topologies that include SEPIC, CUK and FLYBACK DC-DC converters. Both topologies are designed for 8W power and operated in discontinuous conduction mode (DCM) with 88 kHz switching frequency. Furthermore, inductors of SEPIC and CUK converters are wounded as coupled. Applications are realized by using SG3524 integrated circuit for open loop and PIC16F877 microcontroller for closed loop. Besides, ACS712 current sensor used to limit maximum LED current for closed loop applications. Finally, SEPIC, CUK and FLYBACK DC-DC LED drivers are compared with respect to LED current, LED voltage, input voltage and current. Also, advantages and disadvantages of all topologies are concluded.

scholarly journals Parallel Point Clouds: Hybrid Point Cloud Generation and 3D Model Enhancement via Virtual–Real Integration

2021 ◽  
Vol 13 (15) ◽  
pp. 2868
Author(s):  
Yonglin Tian ◽  
Xiao Wang ◽  
Yu Shen ◽  
Zhongzheng Guo ◽  
Zilei Wang ◽  
...  
Keyword(s):  
Point Cloud ◽  
Closed Loop ◽  
Real Data ◽  
Point Clouds ◽  
Autonomous Driving ◽  
Training Model ◽  
Labor Cost ◽  
Open Loop ◽  
Training Dataset ◽  
Data Annotation

Three-dimensional information perception from point clouds is of vital importance for improving the ability of machines to understand the world, especially for autonomous driving and unmanned aerial vehicles. Data annotation for point clouds is one of the most challenging and costly tasks. In this paper, we propose a closed-loop and virtual–real interactive point cloud generation and model-upgrading framework called Parallel Point Clouds (PPCs). To our best knowledge, this is the first time that the training model has been changed from an open-loop to a closed-loop mechanism. The feedback from the evaluation results is used to update the training dataset, benefiting from the flexibility of artificial scenes. Under the framework, a point-based LiDAR simulation model is proposed, which greatly simplifies the scanning operation. Besides, a group-based placing method is put forward to integrate hybrid point clouds, via locating candidate positions for virtual objects in real scenes. Taking advantage of the CAD models and mobile LiDAR devices, two hybrid point cloud datasets, i.e., ShapeKITTI and MobilePointClouds, are built for 3D detection tasks. With almost zero labor cost on data annotation for newly added objects, the models (PointPillars) trained with ShapeKITTI and MobilePointClouds achieved 78.6% and 60.0% of the average precision of the model trained with real data on 3D detection, respectively.

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