control challenge
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2021 ◽  
Vol 54 (5) ◽  
pp. 693-698
Author(s):  
Mohd Ikhmil Fadzrizan Mohd Hanif ◽  
Mohd Ashraf Ahmad ◽  
Julakha Jahan Jui

This paper proposed the chaotic safe experimentation dynamics algorithm (CSEDA) to regulate angular tracking and vibration of the self-tuning PID controller for elastic joint manipulators. CSEDA was a modified version of the safe experimentation dynamics algorithm (SEDA) that used a chaos function in the updated equation. The chaos function increased the exploration capability, thus improving the convergence accuracy. In this study, two self-tuning PID controllers were used to regulate the rotating angle tracking and vibration for elastic joint manipulators in this control challenge. The suggested self-tuning PID controller's performance was evaluated in angular motion trajectory tracking, vibration suppression, and the pre-determined control fitness function. A self-tuned PID controller based on CSEDA could achieve superior control accuracy than a traditional SEDA and its variants.


2021 ◽  
pp. 154596832110347
Author(s):  
Lin Wang ◽  
Omid A. Zobeiri ◽  
Jennifer L. Millar ◽  
Wagner Souza Silva ◽  
Michael C. Schubert ◽  
...  

Background. The vestibular system is vital for gaze stability via the vestibulo-ocular reflex, which generates compensatory eye motion in the direction opposite to head motion. Consequently, individuals with peripheral vestibular loss demonstrate impaired gaze stability that reduces functional capacity and quality of life. To facilitate patients’ compensatory strategies, two classes of gaze stabilization exercises are often prescribed: (i) transient (eg, ballistic) and (ii) continuous. However, the relative benefits of these two classes of exercises are not well understood. Objective. To quantify head motion kinematics in patients with vestibular loss while they performed both classes of exercises. Methods. Using inertial measurement units, head movements of 18 vestibular schwannoma patients were measured before and after surgical deafferentation and compared with age-matched controls. Results. We found that the head movement during both classes of exercises paralleled those of natural head movement recorded during daily activities. However, head movement patterns were more informative for continuous than transient exercises in distinguishing patients from healthy controls. Specifically, we observed coupling between kinematic measures in control subjects that was absent in patients for continuous but not transient head motion exercises. In addition, kinematic measures (eg, cycle duration) were predictive of standard clinical measures for continuous but not transient head motion exercises. Conclusions. Our data suggest that performing continuous head motion is a greater motor control challenge than transient head motion in patients with less reliable vestibular feedback during the sub-acute stage of recovery, which may also prove to be a reliable measure of progression in vestibular rehabilitation protocols.


2021 ◽  
Vol 17 (2) ◽  
pp. 81-100
Author(s):  
Ruchi Jain Garg ◽  
Vandana ◽  
Vinod Kumar

The present study aims to identify and prioritize the components of customer experience in online environment. The study employs Pareto analysis and interpretive structural modeling (ISM) to accomplish above-mentioned objective. Firstly, 36 components have been derived from extensively reviewed literature, and out of them, 15 were finalized as vital few variables having 80% influence in creating customer experience in online environment. To assess the impact of these 15 components, one outcome component ‘Customer Experience (Flow)' has been added. So, an ISM technique is applied on a total of 16 components of customer experience in online environment. The aim of this technique is to highlight the interrelationships among the components and to prioritize them. Further, the findings are strengthened by using MICMAC analysis. Results revealed that time distortion, skill, focused attention, interactivity, playfulness, start web, and involvement are found to have weak dependence powers but with strong driving powers. However, control, challenge, arousal, telepresence, flow, positive affect, and exploratory behavior were found to possess weak driving power and strong dependence power. The results of the present study carry implications for academicians and marketers handling online experience of their customers.


Aerospace ◽  
2021 ◽  
Vol 8 (3) ◽  
pp. 65
Author(s):  
Yi Lin

In air traffic control (ATC), speech communication with radio transmission is the primary way to exchange information between the controller and aircrew. A wealth of contextual situational dynamics is embedded implicitly; thus, understanding the spoken instruction is particularly significant to the ATC research. In this paper, a comprehensive review related to spoken instruction understanding (SIU) in the ATC domain is provided from the perspective of the challenges, techniques, and applications. Firstly, a full pipeline is represented to achieve the SIU task, including automatic speech recognition, language understanding, and voiceprint recognition. A total of 10 technique challenges are analyzed based on the ATC task specificities. In succession, the common techniques for SIU tasks are categorized from common applications, and extensive works in the ATC domain are also reviewed. Finally, a series of future research topics are also prospected based on the corresponding challenges. The author sincerely hopes that this work is able to provide a clear technical roadmap for the SIU tasks in the ATC domain and further make contributions to the research community.


2021 ◽  
Author(s):  
Hélène Chabas ◽  
Viktor Müller ◽  
Sebastian Bonhoeffer ◽  
Roland R. Regoes

AbstractAdaptive immune systems face a control challenge: they should react with enough strength to clear an infection while avoiding to harm their organism. CRISPR-Cas systems are adaptive immune systems of prokaryotes that defend against fast evolving viruses. Here, we explore the CRISPR-Cas control challenge and look how its reactivity, i.e. its probability to acquire a new resistance, impacts the epidemiological outcome of a phage outbreak and the prokaryote’s fitness. We show that in the absence of phage evolution, phage extinction is driven by the probability to acquire at least one resistance. However, when phage evolution is fast, phage extinction is driven by an epidemiological critical threshold: any reactivity below this critical threshold leads to phage survival whereas any reactivity above it leads to phage extinction. We also show that in the absence of autoimmunity, high levels of reactivity evolve. However, when CRISPR-Cas systems are prone to autoimmune reactions, intermediate levels of reactivity are evolutionarily optimal. These results help explaining why natural CRISPR-Cas systems do not show high levels of reactivity.


Vaccines ◽  
2021 ◽  
Vol 9 (1) ◽  
pp. 37
Author(s):  
Vilmos Palya ◽  
Tímea Tatár-Kis ◽  
Abdel Satar A. Arafa ◽  
Balázs Felföldi ◽  
Tamás Mató ◽  
...  

The control of Newcastle disease (ND) highly relies on vaccination. Immunity provided by a ND vaccine can be characterized by measuring the level of clinical protection and reduction in challenge virus shedding. The extent of shedding depends a lot on the characteristics of vaccine used and the quality of vaccination, but influenced also by the genotype of the challenge virus. We demonstrated that vaccination of SPF chicks with recombinant herpesvirus of turkey expressing the F-gene of genotype I ND virus (rHVT-ND) provided complete clinical protection against heterologous genotype VII.1.1 ND virus strain and reduced challenge virus shedding significantly. 100% of clinical protection was achieved already by 3 weeks of age, irrespective of the challenge route (intra-muscular or intra-nasal) and vaccination blocked cloacal shedding almost completely. Interestingly, oro-nasal shedding was different in the two challenge routes: less efficiently controlled following intra-nasal than intra-muscular challenge. Differences in the shedding pattern between the two challenge routes indicate that rHVT-ND vaccine induces strong systemic immunity, that is capable to control challenge virus dissemination in the body (no cloacal shedding), even when it is a heterologous strain, but less efficiently, although highly significantly (p < 0.001) suppresses the local replication of the challenge virus in the upper respiratory mucosa and consequent oro-nasal shedding.


2021 ◽  
Vol 6 (1) ◽  
pp. 229-241
Author(s):  
Fouad Haouari ◽  
Salaheddine Messekher ◽  
Noureddine Bali ◽  
Mohamed Tadjine ◽  
Mohamed Seghir Boucherit

Abstract Due to the external disturbances, model uncertainties, strong coupling, and occurred faults, the winding machine presents a great control challenge. In order to deal with these problems, this paper presents the formulation of a novel scheme of fault tolerant control (FTC) for three-motor web-winding systems; it is concerned with the nonlinear robust backstepping control based on the combination of RST and backstepping controllers where the process is modelled by a nonlinear model. The main contribution of the paper is that the approach developed here summarises the performance of RST and backstepping controllers in order to design a robust controller capable of eliminating external disturbances and sensor faults affecting the system. The stability of the whole system is proven using the Lyapunov theory. Finally, analysis in comparison with the conventional backstepping controller and simulations in the MATLAB environment are accomplished to confirm the efficiency of the proposed method.


2020 ◽  
Vol 120 (3) ◽  
pp. 567-577
Author(s):  
Francisco J. Vera-Garcia ◽  
Belen Irles-Vidal ◽  
Amaya Prat-Luri ◽  
María Pilar García-Vaquero ◽  
David Barbado ◽  
...  

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