Workload modeling using time windows and utilization in an air traffic control task

In this paper, we show how to assess human workload for continuous tasks and describe how operator performance is affected by variations in break-work intervals and by different utilizations. A study was conducted examining the effects of different break-work intervals and utilization as a factor in a mental workload model. We investigated the impact of operator performance on operational error while performing continuous event-driven air traffic control tasks with multiple aircraft. To this end we have developed a simple air traffic control (ATC) model aimed at distributing breaks to form different configurations with the same utilization. The presented approach extends prior concepts of workload and utilization, which are based on a simple average utilization, and considers the specific patterns of break-work intervals. Copyright 2011 by Human Factors and Ergonomics Society, Inc. All rights reserved

La Chasse Infernale : Grand Galop Brillant

https://digitalcommons.library.umaine.edu/mmb-ps/1308/thumbnail.jp

Occlusion-based cooperative transport with a swarm of miniature mobile robots

This paper proposes a strategy for transporting a large object to a goal using a large number of mobile robots that are significantly smaller than the object. The robots only push the object at positions where the direct line of sight to the goal is occluded by the object. This strategy is fully decentralized and requires neither explicit communication nor specific manipulation mechanisms. We prove that it can transport any convex object in a planar environment. We implement this strategy on the e-puck robotic platform and present systematic experiments with a group of 20 e-pucks transporting three objects of different shapes. The objects were successfully transported to the goal in 43 out of 45 trials. When using a mobile goal, teleoperated by a human, the object could be navigated through an environment with obstacles. We also tested the strategy in a 3-D environment using physics-based computer simulation. Due to its simplicity, the transport strategy is particularly suited for implementation on microscale robotic systems

Human-robot swarm interaction with limited situational awareness

This paper studies how an operator with limited situational awareness can collaborate with a swarm of simulated robots. The robots are distributed in an environment with wall obstructions. They aggregate autonomously but are unable to form a single cluster due to the obstructions. The operator lacks the bird’s-eye perspective, but can interact with one robot at a time, and influence the behavior of other nearby robots. We conducted a series of experiments. They show that untrained participants had marginal influence on the performance of the swarm. Expert participants succeeded in aggregating 85% of the robots while untrained participants, with bird’s-eye view, succeeded in aggregating 90%. This demonstrates that the controls are sufficient for operators to aid the autonomous robots in the completion of the task and that lack of situational awareness is the main difficulty. An analysis of behavioral differences reveals that trained operators learned to gain superior situational awareness

Characteristics and outcome of 16 periprosthetic shoulder joint infections

Purpose: Shoulder arthroplasties are increasingly performed, but data on periprosthetic joint infections (PJI) in this anatomical position are limited. We retrospectively investigated the characteristics and outcome of shoulder PJI after primary arthroplasty from 1998 to 2010 in a single centre. Methods: Periprosthetic joint infection was defined as periprosthetic purulence, presence of sinus tract or microbial growth. A Kaplan-Meier survival method was used to estimate relapse-free survival of prosthesis. Results: From 1,571 primary shoulder prostheses, we evaluated 16 patients with a PJI at different stages, i.e, early (n=4), delayed (n=6) and late (n=6) infections. The median patient age was 67 (range 53-86) years, and 69% were females. The most commonly isolated microorganism was Propionibacterium acnes in 38% of patients (monobacterial in four and polymicrobial in two patients). In 14 of the 16 patients, surgical interventions consisting of debridement and implant retention (6 patients), exchange (7) and explantation (1) were performed. Four patients had a relapse of infection with P. acnes (n=3) or Bacteroides fragilis (n=1). The relapse-free survival of the prosthesis was 75% (95% confidence interval 46-90%) after 1 and 2years, 100% in six patients following the treatment algorithm for hip and knee PJI and 60% in 10 patients not followed up. All but one of the relapses were previously treated without exchange of the prosthesis. Conclusions: As recommended for hip and knee PJI, we suggest treating shoulder PJI with a low-grade infection by microorganisms such as P. acnes with an exchange of the prosthesis. Cohort studies are needed to verify our result

Robotic swarm connectivity with human operation and bandwidth limitations

Human interaction with robot swarms (HSI) is a young field with very few user studies that explore operator behavior. All these studies assume perfect communication between the operator and the swarm. A key challenge in the use of swarm robotic systems in human supervised tasks is to understand human swarm interaction in the presence of limited communication bandwidth, which is a constraint arising in many practical scenarios. In this paper, we present results of human-subject experiments designed to study the effect of bandwidth limitations in human swarm interaction. We consider three levels of bandwidth availability in a swarm foraging task. The lowest bandwidth condition performs poorly, but the medium and high bandwidth condition both perform well. In the medium bandwidth condition, we display useful aggregated swarm information (like swarm centroid and spread) to compress the swarm state information. We also observe interesting operator behavior and adaptation of operators' swarm reaction

Investigating neglect benevolence and communication latency during human-swarm interaction

In practical applications of robot swarms with bioinspired behaviors, a human operator will need to exert control over the swarm to fulfill the mission objectives. In many operational settings, human operators are remotely located and the communication environment is harsh. Hence, there exists some latency in information (or control command) transfer between the human and the swarm. In this paper, we conduct experiments of human-swarm interaction to investigate the effects of communication latency on the performance of a humanswarm system in a swarm foraging task.We develop and investigate the concept of neglect benevolence, where a human operator allows the swarm to evolve on its own and stabilize before giving new commands. Our experimental results indicate that operators exploited neglect benevolence in different ways to develop successful strategies in the foraging task. Furthermore, we show experimentally that the use of a predictive display can help mitigate the adverse effects of communication latency