scholarly journals An adaptive weighting mechanism for Reynolds rules-based flocking control scheme

2021 ◽  
Vol 7 ◽  
pp. e388
Author(s):  
Duc N. M. Hoang ◽  
Duc M. Tran ◽  
Thanh-Sang Tran ◽  
Hoang-Anh Pham
Keyword(s):  
Allocation Mechanism ◽  
Behavioral Rules ◽  
Control Scheme ◽  
Adaptive Weight ◽  
Current Context ◽  
Overall Performance ◽  
Optimal Values ◽  
Improved Performance ◽  
Weighting Coefficients ◽  
Weight Allocation

Cooperative navigation for fleets of robots conventionally adopts algorithms based on Reynolds's flocking rules, which usually use a weighted sum of vectors for calculating the velocity from behavioral velocity vectors with corresponding fixed weights. Although optimal values of the weighting coefficients giving good performance can be found through many experiments for each particular scenario, the overall performance could not be guaranteed due to unexpected conditions not covered in experiments. This paper proposes a novel control scheme for a swarm of Unmanned Aerial Vehicles (UAVs) that also employs the original Reynolds rules but adopts an adaptive weight allocation mechanism based on the current context than being fixed at the beginning. The simulation results show that our proposed scheme has better performance than the conventional Reynolds-based ones in terms of the flock compactness and the reduction in the number of crashed swarm members due to collisions. The analytical results of behavioral rules’ impact also validate the proposed weighting mechanism's effectiveness leading to improved performance.

Gamified Learning

2022 ◽  
pp. 97-131
Author(s):  
Cornelia Nih Popescu ◽  
Elodie Attie ◽  
Laëtitia CHADOUTEAU
Keyword(s):  
Learning Outcomes ◽  
Control Group ◽  
Training And Education ◽  
Learning Module ◽  
Important Concern ◽  
E Learning ◽  
Current Context ◽  
Overall Performance ◽  
Gamified Learning ◽  
Experimental Group

In the context of the current COVID-19 pandemic, e-learning represents a more and more important concern of all education providers and an inevitable direction for the current context in training and education. This chapter follows the theory of gamified learning and the theory of flow to understand to which extent game characteristics improve engagement and learning outcomes, such as performance and engagement. To do this, two groups of learners (N=20) were randomly assigned: the experimental group followed a gamified learning module, and the control group followed the same content without gamification mechanisms. The game mechanisms chosen involve a game, a challenge, virtual rewards, an avatar, a final badge, and a system of points and levels. Results show that the gamified course increased the time spent on the course and the overall performance. Hence, this chapter demonstrates the relevance of using gamification to improve learning outcomes.

scholarly journals Increased Performance in Elite Runners Following Individualized Timing of Sodium Bicarbonate Supplementation

2021 ◽  
pp. 1-7
Author(s):  
Tue A.H. Lassen ◽  
Lars Lindstrøm ◽  
Simon Lønbro ◽  
Klavs Madsen
Keyword(s):  
Sodium Bicarbonate ◽  
Body Mass ◽  
Time Trial ◽  
Buffer System ◽  
Double Blind ◽  
Warm Up ◽  
Time To Peak ◽  
Before And After ◽  
Overall Performance ◽  
Improved Performance

The present study investigated individualized sodium bicarbonate (NaHCO3−) supplementation in elite orienteers and its effects on alkalosis and performance in a simulated sprint orienteering competition. Twenty-one Danish male and female elite orienteers (age = 25.2 ± 3.6 years, height = 176.4 ± 10.9 cm, body mass = 66.6 ± 7.9 kg) were tested twice in order to identify individual time to peak blood bicarbonate (HCO3− peak) following supplementation of 0.3 g/kg body mass NaHCO3 with and without warm-up. The athletes also performed two 3.5 km time-trial runs (TT-runs) following individualized timing of NaHCO3 supplementation (SBS) or placebo (PLA) on separate days in a randomized, double-blind, cross-over design. The occurrence of individual peak HCO3− and pH ranged from 60 to 180 min. Mean HCO3− and pH in SBS were significantly higher compared with PLA 10 min before and following the TT-run (p < .01). SBS improved overall performance in the 3.5 km TT-run by 6 s compared with PLA (775.5 ± 16.2 s vs. 781.4 ± 16.1 s, respectively; p < .05). SBS improved performance in the last half of the TT-run compared with PLA (p < .01). In conclusion, supplementation with NaHCO3 followed by warm-up resulted in individualized alkalosis peaks ranging from 60 to 180 min. Individualized timing of SBS in elite orienteers induced significant alkalosis before and after a 3.5 km TT and improved overall performance time by 6 s, which occurred in the last half of the time trial. The present data show that the anaerobic buffer system is important for performance in these types of endurance events lasting 12–15 min.

scholarly journals Improved performance with fractional order control for asymmetrical cascaded H-bridge multilevel inverter

2020 ◽  
Vol 9 (4) ◽  
pp. 1335-1344
Author(s):  
Vemula Anil Kumar ◽  
Arounassalame Mouttou
Keyword(s):  
Fractional Order ◽  
Pid Controller ◽  
Output Voltage ◽  
Model Simulation ◽  
Harmonic Distortion ◽  
Simplified Model ◽  
Control Scheme ◽  
In Series ◽  
Improved Performance ◽  
Fractional Order Pid

This paper proposes a control scheme for seven level asymmetrical cascaded H-bridge multi level inverter (ACHBMLI) based on fractional order calculus. The seven level ACHBMLI consists of two H-bridges that are connected in series and are excited by different dc voltage sources. A simplified model is developed by assuming the small signal variation component is equal in both the H-bridges. A fractional order PID (FO-PID) controller is designed for the ACHBMLI using the simplified model. Simulation study shows the adequacy of FO-PID controller in giving an output voltage with minimum distortions. A conventional PID controller is also designed for ACHBMLI using the same simplified model. The performance of the ACHBMLI with FO-PID controller is compared with the performance of ACHBMLI with conventional PID controller. The simulation results prove the superiority of FO-PID controller in maintaining the output voltage of the ACHBMLI close to the reference voltage and in reducing the harmonic distortion of output voltage of the inverter. The simulation was done using MATLAB and the parameters of FO-PID controller was designed using FOMCON tool box.

scholarly journals An Effective Conversion of Visemes to Words for High-Performance Automatic Lipreading

Sensors ◽  
2021 ◽  
Vol 21 (23) ◽  
pp. 7890
Author(s):  
Souheil Fenghour ◽  
Daqing Chen ◽  
Kun Guo ◽  
Bo Li ◽  
Perry Xiao
Keyword(s):  
Classification Accuracy ◽  
High Performance ◽  
English Language ◽  
High Efficiency ◽  
Alternative Approach ◽  
Overall Performance ◽  
Improved Performance ◽  
Deep Learning Network ◽  
Performance Results ◽  
Gated Recurrent Unit

As an alternative approach, viseme-based lipreading systems have demonstrated promising performance results in decoding videos of people uttering entire sentences. However, the overall performance of such systems has been significantly affected by the efficiency of the conversion of visemes to words during the lipreading process. As shown in the literature, the issue has become a bottleneck of such systems where the system’s performance can decrease dramatically from a high classification accuracy of visemes (e.g., over 90%) to a comparatively very low classification accuracy of words (e.g., only just over 60%). The underlying cause of this phenomenon is that roughly half of the words in the English language are homophemes, i.e., a set of visemes can map to multiple words, e.g., “time” and “some”. In this paper, aiming to tackle this issue, a deep learning network model with an Attention based Gated Recurrent Unit is proposed for efficient viseme-to-word conversion and compared against three other approaches. The proposed approach features strong robustness, high efficiency, and short execution time. The approach has been verified with analysis and practical experiments of predicting sentences from benchmark LRS2 and LRS3 datasets. The main contributions of the paper are as follows: (1) A model is developed, which is effective in converting visemes to words, discriminating between homopheme words, and is robust to incorrectly classified visemes; (2) the model proposed uses a few parameters and, therefore, little overhead and time are required to train and execute; and (3) an improved performance in predicting spoken sentences from the LRS2 dataset with an attained word accuracy rate of 79.6%—an improvement of 15.0% compared with the state-of-the-art approaches.

Plasma-functionalized carbon-layered separators for improved performance of lithium sulfur batteries

2019 ◽  
Vol 7 (8) ◽  
pp. 3772-3782 ◽  
Author(s):  
Jee Hun Ahn ◽  
Hyun-Jin Shin ◽  
Saleem Abbas ◽  
Kwan-Young Lee ◽  
Heung Yong Ha
Keyword(s):  
Lithium Sulfur Batteries ◽  
Carbon Coated ◽  
Overall Performance ◽  
Improved Performance ◽  
Lithium Sulfur

Novel plasma-functionalized carbon-coated separators improve the overall performance of Li–S batteries.

Design of an Optimal Integral Backstepping Controller for a Quadcopter

2018 ◽  
Vol 24 (5) ◽  
pp. 46
Author(s):  
Laith Jasim Saud ◽  
Alaq Falah Hasan
Keyword(s):  
Pid Controller ◽  
Tracking Error ◽  
Absolute Error ◽  
Swarm Optimization ◽  
Full Control ◽  
Integral Action ◽  
Control Scheme ◽  
Optimal Values ◽  
Backstepping Controller ◽  
Yaw Angle

In this paper, an Integral Backstepping Controller (IBC) is designed and optimized for full control, of rotational and translational dynamics, of an unmanned Quadcopter (QC). Before designing the controller, a mathematical model for the QC is developed in a form appropriate for the IBC design. Due to the underactuated property of the QC, it is possible to control the QC Cartesian positions (X, Y, and Z) and the yaw angle through ordering the desired values for them. As for the pitch and roll angles, they are generated by the position controllers. Backstepping Controller (BC) is a practical nonlinear control scheme based on Lyapunov design approach, which can, therefore, guarantee the convergence of the position tracking error to zero. To improve controller capability in the steady state against disturbances, an integral action is used with the BC. To determine the optimal values of the IBC parameters, the Particle Swarm Optimization (PSO) is used. In the algorithm, the controller parameters are computed by minimizing a cost function that depends on the Integral Time Absolute Error (ITAE) performance index. Finally, different numerical simulations are provided in order to illustrate the performances of the designed controller. And for comparison purposes, a PID controller is designed and optimized using the PSO to control the quadcopter. The obtainediresults indicated a superiority in performance for the IBC over the PID controller based on some points among which are: a 13.3% and 30.5% lesser settling times for X and Y consequently, the ability to perform critical maneuvers that the quadcopter failed to do using the PID controller, and the capability of fast following up and conforming the changes of pitch (

Shipyard Technology Development Strategies

1997 ◽  
Vol 13 (04) ◽  
pp. 290-300
Author(s):  
Richard Birmingham ◽  
Sue Hall ◽  
Raouf Kattan
Keyword(s):  
Technology Development ◽  
Technological Development ◽  
Development Strategies ◽  
Capital Investments ◽  
Technological Developments ◽  
Overall Performance ◽  
Improved Performance ◽  
The Individual ◽  
Effective Development ◽  
The Impact

Effective development strategies for shipyards need to recognize the different economic and technological environments in which individual organizations operate. The benefits of implementing a given technology will vary according to the different cost structure, labor market and technological development of the individual shipyard. Specifically, capital investments in expensive hardware, can lead to a deterioration of the overall performance of the business, whereas improvement in the organization and practices of the business may produce improved performance from the existing hardware and facilities. Development strategies must be targeted towards quantifiable improvements against the needs of the market or competition and must recognize the impact of different technologies on the performance of the particular yard. This paper looks at the issues involved and appraisal techniques to support effective investment in hard and soft technological developments.

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