Browsing by Author "Lim, Sol"

Now showing 1 - 7 of 7
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    Changes in forklift driving performance and postures among novices resulting from training using a high-fidelity virtual reality simulator: An exploratory study
    Islam, Md Shafiqul; Zahabi, Saman Jamshid Nezhad; Kim, Sunwook; Lau, Nathan; Nussbaum, Maury A.; Lim, Sol (Elsevier, 2024-11-01)
    Virtual reality (VR) has emerged as a promising tool for training. Our study focused on training for forklift driving, to address an ongoing worker shortage, and the unknown impact of repeated VR training on task performance and kinematic adaptations. We trained 20 novice participants using a VR forklift simulator over two days, with two trials on each day, and including three different driving lessons of varying difficulties. Driving performance was assessed using task completion time, and we quantified kinematics of the head, shoulder, and lumbar spine. Repeated training reduced task completion time (up to ∌29.8% of initial trial) and decreased both kinematic variability and peak range of motion, though these effects were larger for lessons requiring higher precision than simple driving maneuvers. Our results highlight the potential of VR as an effective training environment for novice drivers and suggest that monitoring kinematics could help track skill acquisition during such training.
  • Cognitive Workload of Novice Forklift Truck Drivers in VR-based Training
    Jamshid Nezhad Zahabi, Saman; Shafiqul Islam, Md; Kim, Sunwook; Lau, Nathan; Nussbaum, Maury A.; Lim, Sol (SAGE, 2023-10-19)
    There is increasing use of Virtual Reality (VR) to train forklift truck operators but a lack of sufficient understanding of how cognitive workload changes with respect to different task demands in VR-based training. In this study, 19 novice participants completed three forklift driving lessons with varying difficulty levels (low, medium, and high) using a VR simulator. To examine the effect of repeated training on cognitive workload, two sessions were repeated by participants using the same procedures. Cognitive workload was assessed with objective (electroencephalogram [EEG] activity) and subjective (NASA-TLX) measurements. EEG theta power and NASA-TLX (mental workload) scores were significantly higher for high than low difficulty levels. However, both EEG and NASA-TLX responses were reduced with repeated training in the second session. These findings highlight the effectiveness of EEG in continuous monitoring of workload variation caused by task difficulty and implementing training programs to moderate cognitive workload for forklift operators.
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    Context-Aware Sit-Stand Desk for Promoting Healthy and Productive Behaviors
    Hu, Donghan; Bae, Joseph; Lim, Sol; Lee, Sang Won (ACM, 2023-10-29)
    To mitigate the risk of chronic diseases caused by prolonged sitting, sit-stand desks are promoted as an effective intervention to foster healthy behaviors among knowledge workers by allowing periodic posture switching between sitting and standing. However, conventional systems either let users manually switch the mode, and some research visited automated notification systems with pre-set time intervals. While this regular notification can promote healthy behaviors, such notification can act as external interruptions that hinder individuals’ working productivity. Notably, knowledge workers are known to be reluctant to change their physical postures when concentrating. To address these issues, we propose considering work context based on their screen activities to encourage computer users to alternate their postures when it can minimize disruption, promoting healthy and productive behaviors. To that end, we are in the process of building a context-aware sit-stand desk that can promote healthy and productive behaviors. To that end, we have completed two modules: an application that monitors users’ computer’s ongoing activities and a sensor module that can measure the height of sit-stand desks for data collection. The collected data includes computer activities, measured desk height, and their willingness to switch to standing modes and will be used to build an LSTM prediction model to suggest optimal time points for posture changes, accompanied by appropriate desk height. In this work, we acknowledge previous relevant research, outline ongoing deployment efforts, and present our plan to validate the effectiveness of our approach via user studies.
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    Effects of vibrotactile feedback on yoga practice
    Islam, Md Shafiqul; Lee, Sang Won; Harden, Samantha M.; Lim, Sol (Frontiers, 2022-10-31)
    Participating in physical exercise using remote platforms is challenging for people with vision impairment due to their lack of vision. Thus, there is a need to provide nonvisual feedback to this population to improve the performance and safety of remote exercise. In this study, the effects of different nonvisual types of feedback (verbal, vibrotactile, and combined verbal and vibrotactile) for movement correction were tested with 22 participants with normal vision to investigate the feasibility of the feedback system and pilot tested with four participants with impaired vision. The study with normal-vision participants found that nonvisual feedback successfully corrected an additional 11.2% of movements compared to the no-feedback condition. Vibrotactile feedback was the most time-efficient among other types of feedback in correcting poses. Participants with normal vision rated multimodal feedback as the most strongly preferred modality. In a pilot test, participants with impaired vision also showed a similar trend. Overall, the study found providing vibrotactile (or multimodal) feedback during physical exercise to be an effective way of improving exercise performance. Implications for future training platform development with vibrotactile or multimodal feedback for people with impaired vision are discussed.
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    Forklift Driving Performance of Novices with Repeated VR-based Training
    Islam, Md Shafiqul; Jamshid Nezhad Zahabi, Saman; Kim, Sunwook; Lau, Nathan; Nussbaum, Maury A.; Lim, Sol (SAGE, 2023-10-19)
    Virtual reality (VR) has emerged as a promising tool for training novice forklift drivers, but temporal patterns of such improvements are largely unknown. We trained 19 novice participants using an order-picker VR simulator on a selected driving lesson. In two sessions, participant driving performance was assessed using task completion time and kinematics of the head, shoulder, and lumbar spine via inertial measurement units (IMUs). Completion time and head flexion/movement decreased significantly (up to 22.4% and 31.5%, respectively). The observed changes in head motion (flexion/extension) indicate an initial adjustment period to prepare a mental model of the driving task and the control panel, which was also adapted over repeated trials. One implication of our results is that reduced head flexion/extension could be used as an indication of a novice driver’s improved skill during the early stages of training, in terms of familiarizing themselves with vehicle control and the vehicle control panel.
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    Teleoperator-Robot-Human Interaction in Manufacturing: Perspectives from Industry, Robot Manufacturers, and Researchers
    Kim, Sunwook; Hernandez, Ivan; Nussbaum, Maury A.; Lim, Sol (Informa, 2024-02-08)
    OCCUPATIONAL APPLICATIONS: Industrial robots have become an important aspect in modern industry. In the context of human-robot collaboration, enabling teleoperated robots to work in close proximity to local/onsite humans can provide new opportunities to improve human engagement in a distributed workplace. Interviews with industry stakeholders highlighted several potential benefits of such teleoperator-robot-human collaboration (tRHC), including the application of tRHC to tasks requiring both expertise and manual dexterity (e.g., maintenance and highly skilled tasks in sectors including construction, manufacturing, and healthcare), as well as opportunities to expand job accessibility for individuals with disabilities and older individuals. However, interviewees also indicated potential challenges of tRHC, particularly related to human perception (e.g., perceiving remote environments), safety, and trust. Given these challenges, and the current limited information on the practical value and implementation of tRHC, we propose several future research directions, with a focus on human factors and ergonomics, to help realize the potential benefits of tRHC.
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    Unpacking Task Management Tools, Values, and Worker Dynamics
    Hu, Donghan; Bhuiyan, Md Momen; Lim, Sol; Wiese, Jason; Lee, Sang Won (ACM, 2024-06-25)
    As the complexity of daily tasks grows, knowledge workers experience challenges in managing tasks and risk skipping over some. Fortunately, various task management tools have become available, ranging from traditional tools, such as sticky notes, to complex project management software. In this exploratory study, we aim to understand the landscape of task management tools that knowledge workers use and identify the value they seek from such tools. In addition, we investigate how such value relates to workers’ personality traits and job characteristics. For this purpose, we conducted a series of formative studies and an online survey (𝑁 = 248) to evaluate the perceived importance of various attributes of taskmanagement tools, followed by an exploratory factor analysis to identify the latent structure within that. This process revealed six underlying dimensions for task management tools: communicability, structure, portability, adaptability, physicality, and visualizability. Applying regression analysis, we found connections between latent dimensions and both personality traits and job characteristics. Our findings inform the design of future task management tools with guidance on choosing features and functionality that will meet the needs of their target populations.