Shared Control Research Articles

Unified and distinct cognitive control deficits in adolescents with cognitive disengagement syndrome and learning burnout.

Cognitive disengagement syndrome (CDS) is a psychological disorder characterized by daydreaming, mental fogginess, and slow thinking, while learning burnout (LB) is characterized by a passive and inattentive attitude toward learning. These two disorders are closely related but can be challenging to differentiate from one another. The present study aimed to identify shared and distinct cognitive control deficits between CDS and LB. We recruited 136 adolescents (aged 14 to 17 years) from an initial screening of CDS and LB (N = 476) and divided them into four groups: CDS, LB, CDS + LB, and typically developing control. After a second screening, 129 adolescents completed two tasks to assess their attentional networks and cognitive control capacity (CCC). Adolescents with high CDS symptoms (both CDS group and CDS+LB group) exhibited impaired disengaging effect of attention and lower CCC, indicating deficits in orienting attention and the upper limit of information processing for cognitive control specifically. Furthermore, support vector machine modeling identified CCC as the most significant parameter differentiating the CDS and LB groups. Our findings suggest that while adolescents with high CDS and high LB symptoms have similar outward manifestations in the adolescent's school life, deficits in attention and cognitive control, particularly in the CCC, may distinguish between the two groups.

Fuzzy Logic-Based Arbitration for Shared Control in Continuous Human–Robot Collaboration

Fuzzy Logic-Based Arbitration for Shared Control in Continuous Human–Robot Collaboration

Decentralized Dynamic Power Sharing Control for Frequency Regulation Using Hybrid Hydrogen Electrolyzer Systems

Decentralized Dynamic Power Sharing Control for Frequency Regulation Using Hybrid Hydrogen Electrolyzer Systems

Human–Machine Shared Control for Path Following Considering Driver Fatigue Characteristics

Human–Machine Shared Control for Path Following Considering Driver Fatigue Characteristics

AdaptiX - A Transitional XR Framework for Development and Evaluation of Shared Control Applications in Assistive Robotics

With the ongoing efforts to empower people with mobility impairments and the increase in technological acceptance by the general public, assistive technologies, such as collaborative robotic arms, are gaining popularity. Yet, their widespread success is limited by usability issues, specifically the disparity between user input and software control along the autonomy continuum. To address this, shared control concepts provide opportunities to combine the targeted increase of user autonomy with a certain level of computer assistance. This paper presents the free and open-source AdaptiX XR framework for developing and evaluating shared control applications in a high-resolution simulation environment. The initial framework consists of a simulated robotic arm with an example scenario in Virtual Reality (VR), multiple standard control interfaces, and a specialized recording/replay system. AdaptiX can easily be extended for specific research needs, allowing Human-Robot Interaction (HRI) researchers to rapidly design and test novel interaction methods, intervention strategies, and multi-modal feedback techniques, without requiring an actual physical robotic arm during the early phases of ideation, prototyping, and evaluation. Also, a Robot Operating System (ROS) integration enables the controlling of a real robotic arm in a PhysicalTwin approach without any simulation-reality gap. Here, we review the capabilities and limitations of AdaptiX in detail and present three bodies of research based on the framework. AdaptiX can be accessed at https://adaptix.robot-research.de.

Guiding real-world reinforcement learning for in-contact manipulation tasks with Shared Control Templates

The requirement for a high number of training episodes has been a major limiting factor for the application of Reinforcement Learning (RL) in robotics. Learning skills directly on real robots requires time, causes wear and tear and can lead to damage to the robot and environment due to unsafe exploratory actions. The success of learning skills in simulation and transferring them to real robots has also been limited by the gap between reality and simulation. This is particularly problematic for tasks involving contact with the environment as contact dynamics are hard to model and simulate. In this paper we propose a framework which leverages a shared control framework for modeling known constraints defined by object interactions and task geometry to reduce the state and action spaces and hence the overall dimensionality of the reinforcement learning problem. The unknown task knowledge and actions are learned by a reinforcement learning agent by conducting exploration in the constrained environment. Using a pouring task and grid-clamp placement task (similar to peg-in-hole) as use cases and a 7-DoF arm, we show that our approach can be used to learn directly on the real robot. The pouring task is learned in only 65 episodes (16 min) and the grid-clamp placement task is learned in 75 episodes (17 min) with strong safety guarantees and simple reward functions, greatly alleviating the need for simulation.

Effects of Shared Control on Cognitive Load and Trust in Teleoperated Trajectory Tracking

Effects of Shared Control on Cognitive Load and Trust in Teleoperated Trajectory Tracking

Bayesian Optimal Designs for Multi-Arm Multi-Stage Phase II Randomized Clinical Trials with Multiple Endpoints

There is a growing need to evaluate of multiple competing drugs in phase II trials where the number of patients is often limited, and simultaneous assessment of both efficacy and toxicity is crucial. To avoid the waste of research resources, it is indeed more efficient to screen multiple drugs at once in a platform phase II setting. We aim to adapt the Bayesian optimal phase II (BOP2) design to multi-arm trials for both uncontrolled and controlled settings. The binary efficacy and toxicity endpoints are modeled by a Dirichlet distribution as a vector of four outcomes. Posterior marginal distributions at each analysis are used to derive the monitoring threshold that varies during the trial. We control the family-wise Type I error rate for multiple comparison against a common reference value or a shared control. We conduct simulation studies under both uncontrolled and controlled settings to evaluate the operating characteristics of the proposed design. Our simulations demonstrate that the design exhibits better operating characteristics compared to a design using a constant threshold and is less sensitive to changes in accrual rate relative to what was planned. The design had promising operating characteristics and could be used in phase II oncology clinical trials for evaluating multiple drugs at a time.

A lateralized motor network in order to understand adaptation to visuomotor rotation

Objective. The functional asymmetry between the two brain hemispheres in language and spatial processing is well documented. However, a description of difference in control between the two hemispheres in motor function is not well established. Our primary objective in this study was to examine the distribution of control in the motor hierarchy and its variation across hemispheres. Approach. We developed a computation model termed the bilateral control network and implemented the same in a neural network framework to be used to replicate certain experimental results. The network consists of a simple arm model capable of making movements in 2D space and a motor hierarchy with separate elements coding target location, estimated position of arm, direction, and distance to be moved by the arm, and the motor command sent to the arm. The main assumption made here is the division of direction and distance coding between the two hemispheres with distance coded in the non-dominant and direction coded in the dominant hemisphere. Main results. With this assumption, the network was able to show main results observed in visuomotor adaptation studies. Importantly it showed decrease in error exhibited by the untrained arm while the other arm underwent training compared to the corresponding naïve arm’s performance—transfer of motor learning from trained to the untrained arm. It also showed how this varied depending on the performance variable used—with distance as the measure, the non-dominant arm showed transfer and with direction, dominant arm showed transfer. Significance. Our results indicate the possibility of shared control between the two hemispheres. If indeed found true, this result could have major significance in motor rehabilitation as treatment strategies will need to be designed in order to account for this and can no longer be confined to the arm contralateral to the affected hemisphere.

Switching off: disruptive TMS reveals distinct contributions of the posterior middle temporal gyrus and angular gyrus to bilingual speech production.

The role of the left temporoparietal cortex in speech production has been extensively studied during native language processing, proving crucial in controlled lexico-semantic retrieval under varying cognitive demands. Yet, its role in bilinguals, fluent in both native and second languages, remains poorly understood. Here, we employed continuous theta burst stimulation to disrupt neural activity in the left posterior middle-temporal gyrus (pMTG) and angular gyrus (AG) while Italian-Friulian bilinguals performed a cued picture-naming task. The task involved between-language (naming objects in Italian or Friulian) and within-language blocks (naming objects ["knife"] or associated actions ["cut"] in a single language) in which participants could either maintain (non-switch) or change (switch) instructions based on cues. During within-language blocks, cTBS over the pMTG entailed faster naming for high-demanding switch trials, while cTBS to the AG elicited slower latencies in low-demanding non-switch trials. No cTBS effects were observed in the between-language block. Our findings suggest a causal involvement of the left pMTG and AG in lexico-semantic processing across languages, with distinct contributions to controlled vs. "automatic" retrieval, respectively. However, they do not support the existence of shared control mechanisms within and between language(s) production. Altogether, these results inform neurobiological models of semantic control in bilinguals.

Shareholding control, ownership concentration, and the value of the Brazilian firm

The study analyzes whether the type of shareholding control (dispersed, shared, or dominant) affects agency conflicts by investigating the relationship between shareholding control, ownership concentration, and firm value. The sample is a panel data comprising 1977 firm-year observations from 167 Brazilian firms in the period 2010–2022. Our results show that shared control creates value, whereas dominant control destroys firm value. Voting rights concentration and cash-flow rights reduce the value of firms with dispersed and shared control. However, at firms with dominant control, these firm characteristics increase firm value. Excess voting rights, in turn, destroy the value of firms with shared and dominant control. Our evidence shows that the type of shareholding control influences the nature and magnitude of agency conflicts and the relationship between ownership concentration and firm value. Thus, within an institutional environment, agency conflicts may differ among firms, depending on the type of shareholding control.

Shared Control of Tendon-Driven Continuum Robots Using Visibility-Guaranteed Optimization for Endoscopic Surgery

Shared Control of Tendon-Driven Continuum Robots Using Visibility-Guaranteed Optimization for Endoscopic Surgery

Design of steering wheel torque with human-machine interaction for uncoupled shared steering

In the uncoupled shared steering architecture based on the steering-by-wire (SBW) system, direct access to road feel and automation-related information is unavailable to the driver. To address this problem, this paper proposes a steering wheel torque feedback model that considers human-machine interaction information. First, the model predictive control (MPC) is adopted in lateral vehicle control by automation. Then a fuzzy control-based control authority allocation model is applied to assign the control authority weight between the human driver and automation according to the value of the Path Lateral Hazard (PLH) Factor and the Driver’s Intent Evaluation (DIE) Factor. These two factors reflect the probability of lateral vehicle collision and the intensity of the driver’s driving intention, respectively. Next, the road feel feedback torque and the human-machine interface (HMI) feedback torque is incorporated in the steering wheel feedback torque model to enhance the driver’s experience in SBW vehicles and trust in the automation. The HMI feedback torque is designed to provide human drivers with information on control authority weight variation and desired angle deviation between the human driver and automation. Simulation and experiment results suggest that the proposed uncouple shared control method can accelerate driver acceptance of automation and provide the driver with a more intuitive steering experience.

12 Time to Sustained Recovery between Oral Tablet and Inhaler Placebos in the ACTIV-6 Platform Clinical Trial

OBJECTIVES/GOALS: Platform trials gain efficiency by sharing placebo controls among different study arms. However, the varying routes of administration make it unclear whether participants exposed to different placebos have similar outcomes. As such, we seek to compare outcomes between participants receiving tablet and inhaler placebos in the ACTIV-6 trial. METHODS/STUDY POPULATION: ACTIV-6 is a large, decentralized platform trial exploring repurposed drugs for the treatment of adults with mild to moderate COVID-19. Enrolled participants were randomly assigned to a study arm vs. placebo and then mailed the study drug. They were monitored until symptom resolution or Day 28. Here, we compare outcomes for control participants contributing to the fluticasone furoate study arm, in which 251 were assigned to a tablet placebo and 370 an inhaler placebo. Time to sustained recovery and time to resolution of individual symptoms are compared between groups using Kaplan-Meier curves and unadjusted log-rank tests. A step-down procedure is applied to control the false discovery rate. RESULTS/ANTICIPATED RESULTS: Control participants assigned to tablet placebos had shorter time to sustained recovery (adjusted hazard ratio (HR) 1.34 (95% CI 1.11, 1.62)). When examining each of the eleven individually reported symptoms on study Day 14, nasal symptoms (adjusted odds ratio (OR) 0.44 (0.27, 0.72), p<0.01), dyspnea (OR 0.44 (0.22, 0.87), p = 0.02), and cough (OR 0.54 (0.35, 0.83), p<0.01) were identified as symptoms in which the tablet-placebo group performed notably better than those who received inhaler-placebos. In the follow-up, longitudinal analysis, we anticipate similar results. DISCUSSION/SIGNIFICANCE: Among ACTIV-6 control participants, those receiving a tablet placebo had a significantly shorter time to sustained recovery than those receiving an inhaler placebo. Platform trials using shared controls should consider efficiency in the context of the additional variability when sharing controls with a different route of administration.

Virtual-Fixtures Based Shared Control Method for Curve-Cutting With a Reciprocating Saw in Robot-Assisted Osteotomy

Virtual-Fixtures Based Shared Control Method for Curve-Cutting With a Reciprocating Saw in Robot-Assisted Osteotomy

Genetic control of DNA methylation is largely shared across European and East Asian populations

DNA methylation is an ideal trait to study the extent of the shared genetic control across ancestries, effectively providing hundreds of thousands of model molecular traits with large QTL effect sizes. We investigate cis DNAm QTLs in three European (n = 3701) and two East Asian (n = 2099) cohorts to quantify the similarities and differences in the genetic architecture across populations. We observe 80,394 associated mQTLs (62.2% of DNAm probes with significant mQTL) to be significant in both ancestries, while 28,925 mQTLs (22.4%) are identified in only a single ancestry. mQTL effect sizes are highly conserved across populations, with differences in mQTL discovery likely due to differences in allele frequency of associated variants and differing linkage disequilibrium between causal variants and assayed SNPs. This study highlights the overall similarity of genetic control across ancestries and the value of ancestral diversity in increasing the power to detect associations and enhancing fine mapping resolution.

English Language Teachers’ Level of Instructional Behavior at Selected Secondary Schools

This study aimed to examine the level of instructional control among English language teachers in selected secondary schools in Gamo Zone, Ethiopia. The study adopted an analytical survey research design to address the study objective. A census was used to select 62 English language teachers as participants. A validated five-point Likert scale questionnaire was employed to collect quantitative data. Statistical analyses, including one-way analysis of variance (ANOVA) and Games-Howell post hoc analysis, were conducted to determine the level of instructional control among teachers. Additionally, a one-sample t-test was conducted to compare differences between the observed and expected mean values at both scale and subscale levels. The effect size was also utilized to describe the magnitude of instructional control. The findings of the study revealed that English language teachers predominantly employed strong teacher control, followed by marginalized shared and loose control. These results suggest that teachers primarily relied on teacher-centered direct instruction which may potentially lead to achievement gaps among students. Based on these findings, the study recommends that the Gamo Zone Education Department organize on-the-job training for English language teachers on instructional control to empower them to implement varied instructional control types as required thereby promoting a more balanced and inclusive instructional environment. Keywords: Instructional control; Loose control; Shared control; Strong control; Student-centered; Teacher-centered

Optimal allocation strategies in platform trials with continuous endpoints.

Platform trials are randomized clinical trials that allow simultaneous comparison of multiple interventions, usually against a common control. Arms to test experimental interventions may enter and leave the platform over time. This implies that the number of experimental intervention arms in the trial may change as the trial progresses. Determining optimal allocation rates to allocate patients to the treatment and control arms in platform trials is challenging because the optimal allocation depends on the number of arms in the platform and the latter typically varies over time. In addition, the optimal allocation depends on the analysis strategy used and the optimality criteria considered. In this article, we derive optimal treatment allocation rates for platform trials with shared controls, assuming that a stratified estimation and a testing procedure based on a regression model are used to adjust for time trends. We consider both, analysis using concurrent controls only as well as analysis methods using concurrent and non-concurrent controls and assume that the total sample size is fixed. The objective function to be minimized is the maximum of the variances of the effect estimators. We show that the optimal solution depends on the entry time of the arms in the trial and, in general, does not correspond to the square root of allocation rule used in classical multi-arm trials. We illustrate the optimal allocation and evaluate the power and type 1 error rate compared to trials using one-to-one and square root of allocations by means of a case study.

Understanding the Determinants of ‘Shared Control’ in Early Childhood Education in Ghana

Developing children who are autonomous learners and able to contribute constructively to decision-making, forms part of the reasons why the Ghana Education Service, in the year 2019, introduced the Standards-based curriculum for basic education in Ghana. Teachers were, thus, tasked to adopt the constructivist instructional philosophy to help realize this educational goal. Using a sequential mixed method, this research involved basic schools in the Sunyani-west municipal of Ghana as cases. The current study investigated the practice of shared control as a way of developing children’s autonomous learning abilities. The results of the study indicate that teachers hardly allowed learners to contribute to the management and planning of instruction. Teachers’ perception of the learners’ limited cognitive ability, policy constraints (lesson planning system, examination-driven nature of the curriculum), and some socio-cultural factors significantly contributed to the minimal practice of shared control during instruction. Further results show that the GES, ironically, worked against the possibility of ensuring shared control. Recommendations have, therefore, been offered for the consideration of policymakers and curriculum implementers.

Adaptive active inceptor design under shared control architecture for nonlinear pilot-induced oscillations

This paper presents a Shared Control Architecture (SCA) between a human pilot and a smart inceptor for nonlinear Pilot Induced Oscillations (PIOs), e.g., category II or III PIOs. One innovation of this paper is that an intelligent shared control architecture is developed based on the intelligent active inceptor technique, i.e., Smart Adaptive Flight Effective Cue (SAFE-Cue). A deep reinforcement learning approach namely Deep Deterministic Policy Gradient (DDPG) method is chosen to design a gain adaptation mechanism for the SAFE-Cue module. By doing this, the gains of the SAFE-Cue will be intelligently tuned once nonlinear PIOs triggered; meanwhile, the human pilot will receive a force cue from the SAFE-Cue, and will consequently adapting his/her control policy. The second innovation of this paper is that the reward function of the DDPG based gain adaptation approach is constructed according to flying qualities. Under the premise of considering failure situation, task completion qualities and pilot workload are also taken into account. Finally, the proposed approach is validated using numerical simulation experiments with two types of scenarios: lower actuator rate limits and airframe damages. The Inceptor Peak Power-Phase (IPPP) metric is adopted to analyze the human-vehicle system simulation results. Results and analysis show that the DDPG based sharing control approach can well address nonlinear PIO problems consisting of Categories II and III PIO events.