Influences of augmented reality head-worn display type and user interface design on performance and usability in simulated warehouse order picking

Precise Tool to Target Positioning Widgets (TOTTA) in Spatial Environments: A Systematic Review

TOTTA outlines the spatial position and rotation guidance of a real/virtual tool (TO) towards a real/virtual target (TA), which is a key task in Mixed reality applications. The task error can have critical consequences regarding safety, performance, and quality, such as surgical implantology or industrial maintenance scenarios. The TOTTA problem lacks a dedicated study and it is scattered in different domains with isolated designs. This work contributes to a systematic review of the TOTTA visual widgets, studying 70 unique designs from 24 papers. TOTTA is commonly guided by the visual overlap -an intuitive, pre-attentive "collimation" feedback- of simple shaped widgets: Box, 3D Axes, 3D Model, 2D Crosshair, Globe, Tetrahedron, Line, Plane. Our research discovers that TO and TA are often represented with the same shape. They are distinguished by topological elements (e.g. edges/vertices/faces), colors, transparency levels, and added. shapes, widget quantity, and size. Meanwhile some designs provide continuous "during manipulation feedback" relative to the distance between TO and TA by text, dynamic color, sonification, and amplified graphical visualization. Some approaches trigger discrete "TA reached feedback" such as color alteration, added sound, TA shape change, and added text. We found the lack of golden standards, including in testing procedures, as current ones are limited to partial sets with different and incomparable setups (different target configurations, avatar, background, etc.). We also found a bias in participants: right-handed, young male, non-color impaired.

Movement and positioning of a virtual cuboid in 3d space in an augmented reality environment

Human-virtual object interaction is common in both entertainment and work settings. This study investigated the movement time (MT) and subjective rating of difficulty (SRD) for moving a virtual cuboid in a 3D space. The participants wore an augmented reality (AR) headset, picked up a virtual cuboid, and placed it on an assigned target. They rated the SRD of the task on a five-point scale. The effects of the 3D coordinate of the target, sex, and handedness on the MT were analysed. The error placement rate was also recorded. Significant effects of spatial coordinates were found on both MT and SRD. Both single- and two-stage MT modelling were conducted using segmented and unsegmented MT data, respectively. The insignificant prediction error between the models indicates that the two-stage MT model is not superior to the single-stage one. The findings of this study are beneficial to software designers in designing user-friendly AR applications.

The effects of target sizes on biomechanical and cognitive load and task performance of virtual reality interactions

This study evaluated the effects of target sizes on biomechanical and cognitive load and the performance of virtual reality (VR) interactions. In a repeated-measures laboratory study, each of the twenty participants performed standardised VR tasks with three different target sizes: small, medium, and large. During the VR tasks, biomechanical load in the neck and shoulders (joint angles, joint moments, and muscle activity), cognitive load (perceived workload and cognitive stress), and task performance (completion time) were collected. The neck and shoulder joint angles, joint moments, and muscle activities were greater with the large targets compared to the medium and small targets. Moreover, the larger VR targets caused greater temporal demand and longer task completion time compared to the other target sizes. These findings indicate that target sizes in VR interfaces play important roles in biomechanical and cognitive load as well as task performance.

Mixed-method usability investigation of ARROWS: augmented reality for roadway work zone safety

This article explores the usability and user experience challenges of ARROWS, a novel augmented reality (AR) and wearable technology (WT) safety system for roadway work zones, an area with limited existing usability research. We utilized a mixed-method approach with two complementary experiments in indoor and outdoor settings, using the Wizard of Oz methodology and a high-fidelity prototype. We focused on identifying usability challenges, factors contributing to user experience and the distinct needs of highway workers, documenting results using the system usability scale (SUS), the rating scale mental effort (RSME) and a trust score. Participants rated the usability of ARROWS above average in both settings, while making a reasonable level of mental effort. The findings also indicate a significant correlation between perceived trust and usability, highlighting the importance of trust in user experience.

Usability evaluation of augmented reality visualizations on an optical see-through head-mounted display for assisting machine operations

This study explores the effect of using different visual information overlays and guiding arrows on a machine operation task with an optical see-through head-mounted display (OST-HMD). Thirty-four participants were recruited in the experiment. The independent variables included visual information mode (text, animation, and mixed text and animation) and the use of guiding arrows (with and without arrows). In addition, gender difference was also an objective of this study. The task performance indicators were determined based on task completion time and error counts as well as subjective measures (system usability scale, NASA task load index, and immersion scale). This study used the mixed analysis of variance design to evaluate the main and interaction effects. The results showed that males performed better when using the mixed text and animation mode. Females performed better when using the text mode. In addition, using the mixed text and animation mode demonstrated the best outcome in system usability scale and NASA task load index. For the use of guiding arrows, the task completion time was reduced and the system usability scale, NASA task load index, and immersion scale showed positive effects.

Influences of smart glasses on postural control under single- and dual-task conditions for ergonomic risk assessment

Head worn displays have become increasingly popular at workplaces in logistics and assembly lines in recent years. Such displays are expected to improve productivity and safety at the workplace. However, their impact on balance in the workforce is still an open research question. Therefore, we investigated the influence of the Vuzix M400 and Realwear HMT1 smart glasses on postural control. A laboratory study was conducted with eleven participants. Balance parameters were recorded during bilateral quiet stance, together with parameters of cognitive load. The two different smart glasses used in this study were compared with a monitor and a tablet under single-task conditions and while performing a spatial 2-back task. As balance parameters, the prediction ellipse and sample entropy in anteroposterior as well as mediolateral direction of the center-of-pressure data were examined. No significant differences were observed in the cognitive task performance between the devices. The prediction ellipse of the smart glasses was smaller than the tablets but larger than the smartboard. The dynamic of sample entropy data suggests that the use of the spatial 2-back task induces postural sway in the participants. This effect was most profound when looking at the monitor and least recognizable in the data of the tablet.

Alterations in Physical Demands During Virtual/Augmented Reality-Based Tasks: A Systematic Review

The digital world has recently experienced a swift rise in worldwide popularity due to Virtual (VR) and Augmented Reality (AR) devices. However, concrete evidence about the effects of VR/AR devices on the physical workload imposed on the human body is lacking. We reviewed 27 articles that evaluated the physical impact of VR/AR-based tasks on the users using biomechanical sensing equipment and subjective tools. Findings revealed that movement and muscle demands (neck and shoulder) varied in seven and five studies while using VR, while in four and three studies during AR use, respectively, compared to traditional methods. User discomfort was also found in seven VR and three AR studies. Outcomes indicate that interface and interaction design, precisely target locations (gestures, viewing), design of virtual elements, and device type (location of CG as in Head-Mounted Displays) influence these alterations in neck and shoulder regions. Recommendations based on the review include developing comfortable reach envelopes for gestures, improving wearability, and studying temporal effects of repetitive movements (such as effects on fatigue and stability). Finally, a guideline is provided to assist researchers in conducting effective evaluations. The presented findings from this review could benefit designers/evaluations working towards developing more effective VR/AR products.

ARCHIE++ : A Cloud-Enabled Framework for Conducting AR System Testing in the Wild

In this paper, we present ARCHIE++, a testing framework for conducting AR system testing and collecting user feedback in the wild. Our system addresses challenges in AR testing practices by aggregating usability feedback data (collected in situ) with system performance data from that same time period. These data packets can then be leveraged to identify edge cases encountered by testers during unconstrained usage scenarios. We begin by presenting a set of current trends in performing human testing of AR systems, identified by reviewing a selection of recent work from leading conferences in mixed reality, human factors, and mobile and pervasive systems. From the trends, we identify a set of challenges to be faced when attempting to adopt these practices to testing in the wild. These challenges are used to inform the design of our framework, which provides a cloud-enabled and device-agnostic way for AR systems developers to improve their knowledge of environmental conditions and to support scalability and reproducibility when testing in the wild. We then present a series of case studies demonstrating how ARCHIE++ can be used to support a range of AR testing scenarios, and demonstrate the limited overhead of the framework through a series of evaluations. We close with additional discussion on the design and utility of ARCHIE++ under various edge conditions.

An Augmented Reality System with Advanced User Interfaces for Image-Guided Intervention Applications

Augmented Reality (AR) is becoming a more common addition to physicians' repertoire for aiding in resident training and patient interactions. However, the use of augmented reality in clinical settings is still beset with many complications, including the lack of physician control over the systems, set modes of interactions within the system, and physician's lack of familiarity with such AR systems. In this paper, we plan to expand on our previous prostate biopsy AR system by adding in improved user interface systems within the virtual world in order to allow the user to more accurately visualize only parts of the system which they consider to be useful at that time. To accomplish this, we have incorporated three-dimensional virtual sliders built from the ground up, using Unity to afford control over each model's RGB values, as well as their transparency. This means that the user would be able to fully edit the color, and transparency of each individual model in real time as they see fit quickly and easily while still being immersed in the augmented space. This would allow users to view internal holograms while not sacrificing the capability to view the external structure. Such leeway could be invaluable when visualizing a tumor within a prostate and would provide the physician with the capability to view as much or as little of the surrounded virtual models as desired, while providing the option to reinstate the surrounding models at will. The AR system can provide a new approach for potential uses in image-guided interventions including targeted biopsy of the prostate.

Interface Design of Head-Worn Display Application on Condition Monitoring in Aviation

Head-worn displays (HWDs) as timely condition monitoring are increasingly used in aviation. However, interface design characteristics that mainly affect HWD use have not been fully investigated. The aim of this study was to examine the effects of several important interface design characteristics (i.e., the distance between calibration lines and the layouts of vertical and horizontal scale belts) on task performance and user preference between different conditions of display, i.e., HWD or head-up display (HUD). Thirty participants joined an experiment in which they performed flight tasks. In the experiment, the calibration lines' distance was set to three different levels (7, 9 and 11 mrad), and the scale belt layouts included horizontal and vertical scale belt layouts. The scale belts were set as follows: the original vertical scale belt width was set as L, and the horizontal scale belt height as H. The three layouts of the vertical calibration scale belt used were 3/4H, H and 3H/2. Three layouts of horizontal calibration scale belts were selected as 3L/4, L and 3L/2. The results indicated that participants did better with the HWD compared to the HUD. Both layouts of vertical and horizontal scale belts yielded significant effects on the users' task performance and preference. Users showed the best task performance while the vertical calibration scale belts were set as H and horizontal calibration scale belts were set as L, and users generally preferred interface design characteristics that could yield an optimal performance. These findings could facilitate the optimal design of usable head-worn-display technology.

Effects of viewing distance and age on the performance and symptoms in a visual search task in augmented reality

In augmented reality (AR), virtual information is optically combined with the physical environment. In the most frequently used combination technique, optical settings in AR depart from the settings in natural viewing. Depending on the combination of viewing distances of the virtual task and its physical background, this deviation may lower visual performance and cause visual disturbance symptoms. The so-called vergence-accommodation conflict (VAC) has been identified as a cause for the visual disturbance symptoms in AR. In this study, for various distance combinations, the performance and symptoms when performing a search task displayed in a see-through head-mounted display (AR HMD, HoloLens 1st generation, Microsoft, USA) was investigated. The search task was displayed at a virtual distance of either 200 cm or 30 cm, and the real background was viewed either at a distance of 200 cm or 30 cm. Three combinations of viewing distances for the background and the virtual task were studied: 200 cm/200 cm, 200 cm/30 cm, and 30 cm/30 cm. Results revealed that both performance and visual disturbance symptoms depend on the combination of the viewing distances of the physical background and the virtual task. When the physical background was viewed at a distance of 200 cm, younger participants showed a significantly better search performance and reported stronger symptoms compared with older participants, no matter whether the virtual task was performed at 30 cm or at 200 cm. However, with the physical background at a distance of 30 cm, the performance of the younger group dropped to the level of the performance of the older group, and younger participants tended to report a stronger increase in visual disturbance symptoms compared with the older participants. From the AR HMD technology used in this study, it can be concluded that a near viewing distance of the virtual task does not cause a negative impact on performance and visual disturbance symptoms, provided any physical background seen through the AR HMD is not at a near viewing distance. The findings indicate that the VAC, which persists in augmented and virtual reality, depends, in addition to the physical component evaluating the optical distance, on a cognitive component evaluating the perceived distance. AR settings should therefore also be evaluated in terms of possible effects on perceived distance.

Putting head-worn displays to use for order picking: a most-similar comparative case study

Purpose

This paper aims to identify why warehouses do or do not succeed in putting to use digital technologies for order picking.

Design/methodology/approach

Building on structuration theory, the authors investigate the situated use of one such a digital technology, more particularly the head-worn display (HWD). Based on a most-similar comparative case study of two Belgian warehouses pioneering HWDs, the authors focus on whether and how order pickers and their manager interact to modify the properties, functionalities, and the context in which the HWD is used.

Findings

In one warehouse, using the HWD was discontinued after implementation. In the other, order pickers and the order pickers' manager succeeded in implementing the HWD into their work. The authors find that the prime explanation for these opposite findings lies in the extent to which order pickers were given room to improve the properties and functionalities of the HWD as well as the conditions that unfold in the HWD's use context. In the latter warehouse, pressing issues were overcome and improvement suggestions were implemented, both regarding the HWD itself as well as regarding the job-related and person-related conditions.

Originality/value

Theoretically, the authors contribute to the situated use of technology stating that (1) giving room to alter the use of digital technologies, and (2) fostering continuous employee participation regarding conditions stemming from the use context are necessary to realize the promising and unexploited potential of digital technology in practice. Empirically, this paper exposes distinct types of interactions that explain whether and how digital technologies, in particular HWDs, are put to use for order picking practices.

Head-Mounted and Hand-Held Displays Diminish the Effectiveness of Fall-Resisting Skills

Use of head-mounted displays (HMDs) and hand-held displays (HHDs) may affect the effectiveness of stability control mechanisms and impair resistance to falls. This study aimed to examine whether the ability to control stability during locomotion is diminished while using HMDs and HHDs. Fourteen healthy adults (21–46 years) were assessed under single-task (no display) and dual-task (spatial 2-n-back presented on the HMD or the HHD) conditions while performing various locomotor tasks. An optical motion capture system and two force plates were used to assess locomotor stability using an inverted pendulum model. For perturbed standing, 57% of the participants were not able to maintain stability by counter-rotation actions when using either display, compared to the single-task condition. Furthermore, around 80% of participants (dual-task) compared to 50% (single-task) showed a negative margin of stability (i.e., an unstable body configuration) during recovery for perturbed walking due to a diminished ability to increase their base of support effectively. However, no evidence was found for HMDs or HHDs affecting stability during unperturbed locomotion. In conclusion, additional cognitive resources required for dual-tasking, using either display, are suggested to result in delayed response execution for perturbed standing and walking, consequently diminishing participants’ ability to use stability control mechanisms effectively and increasing the risk of falls.

A head mounted augmented reality design practice for maintenance assembly: Toward meeting perceptual and cognitive needs of AR users

Head Mounted Display (HMD) based Augmented Reality (AR) is being increasingly used in manufacturing and maintenance. However, limited research has been done to understand user interaction with AR interfaces, which may lead to poor usability, risk of occupational hazards, and low acceptance of AR systems. This paper uses a theoretically-driven approach to interaction design to investigate the impact of different AR modalities in terms of information mode (i.e. video vs. 3D animation) and interaction modality (i.e. hand-gesture vs. voice command) on user performance, workload, eye gaze behaviours, and usability during a maintenance assembly task. The results show that different information modes have distinct impacts compared to paper-based maintenance, in particular, 3D animation led to a 14% improvement over the video instructions in task completion time. Moreover, insights from eye gaze behaviours such as number of fixations and transition between Areas of Interest (AOIs) revealed the differences in attention switching and task comprehension difficulty with the choice of AR modalities. While, subjective user perceptions highlight some ergonomic issues such as misguidance and overreliance, which must be considered and addressed from the joint cognitive systems' (JCSs) perspective and in line with the predictions derived from the Multiple Resources Model.

The effects of target size and error rate on the cognitive demand and stress during augmented reality interactions

This study investigated the effects of target size and error rate on cognitive demand during augmented reality (AR) interactions. In a repeated-measures laboratory study, twenty participants performed two AR tasks (omni-directional pointing and cube placing) with different target sizes and error rates. During the AR tasks, we measured cerebral oxygenation using functional near-infrared spectroscopy (fNIRS), perceived workload using the NASA-TLX questionnaire, stress using the Short Stress State Questionnaire, and task performance (task completion time). The results showed that the AR tasks with more interaction errors increased cerebral oxygenation, perceived workload, and task completion time while the target size significantly affected physical demand and task completion time. These results suggest that appropriate target sizes and low system errors may reduce potential cognitive demand in AR interactions.

Opportunities and Challenges of Smartglass-Assisted Interactive Telementoring

The widespread adoption of wearables, extended reality, and metaverses has accelerated the diverse configurations of remote collaboration and telementoring systems. This paper explores the opportunities and challenges of interactive telementoring, especially for wearers of smartglasses. In particular, recent relevant studies are reviewed to derive the needs and trends of telementoring technology. Based on this analysis, we define what can be integrated into smartglass-enabled interactive telementoring. To further illustrate this type of special use case for telementoring, we present five illustrative and descriptive scenarios. We expect our specialized use case to support various telementoring applications beyond medical and surgical telementoring, while harmoniously fostering cooperation using the smart devices of mentors and mentees at different scales for collocated, distributed, and remote collaboration.

Performance differences between instructions on paper vs digital glasses for a simple assembly task

OBJECTIVE

Providing instruction for assembly tasks is essential in modern manufacturing industry, as well as in households for customers that buy products to be assembled at home. Recent technological developments might be able to assist in completing an assembly task faster and more accurately. The aim of this study was to evaluate whether performance and usability differs when instructions for an assembly task are presented on digital glasses versus paper.

METHODS

Participants (n = 63) completed one of three versions of an assembly task (between-subject-design) with LEGO® bricks: (1) with paper instruction (P), (2) with text instructions presented stepwise via digital glasses (GT), (3) with stepwise text and auditory instruction (in parallel) on digital glasses (GA). Outcome measures on performance were completion time and errors. Furthermore, usability was measured by the User Experience Questionnaire, the Standardized Usability Questionnaire, the Post-Study Usability Questionnaire, and cognitive processing skills were assessed by the Trail Making Test and different versions of the Eriksen Flanker Task. Analyses were adjusted for the confounding factors age, gender, experience with glasses and LEGO, and problems with instruction.

RESULTS

Findings indicate that task completion was faster with the paper instructions compared to both versions of instruction via digital glasses (GT, GA). We observed no difference in accuracy and usability between the instructions. "Novelty" was rated higher for instructions for both GT and GA, compared to P.

DISCUSSION

Results show that instructions on digital glasses may not always be more effective for assembly than the traditional paper-based instructions. Further studies are necessary to investigate whether effectiveness may depend on task complexity, target group, experience of the user with task and device, and how the information is presented.

A review of augmented reality systems and their effects on mental workload and task performance

Augmented Reality (AR) systems have been shown to positively affect mental workload and task performance across a broad range of application contexts. Despite the interest in mental workload and the increasing number of studies evaluating AR use, an attempt has yet to be made to identify the relationship between the effects of AR on mental workload and task performance. This paper seeks to address this gap in AR technology literature. With a better understanding how AR affects mental workload and task performance, researchers and developers can design more effective AR systems. 34 articles investigating the effects of the use of AR systems were selected for the review. A positive correlation was found between effects on mental workload and effects on task performance: if the effect on mental workload is positive, then the effects on task performance are more likely to be positive as well, and vice versa. Effectiveness of AR systems were shown to be influenced by the type of AR display device used, relevance and timeliness of content, information presentation, user characteristics and task characteristics. Additionally, the paper addresses the use of the concept of mental workload and limitations in current literature.

Adaptation of Extended Reality Smart Glasses for Core Nursing Skill Training Among Undergraduate Nursing Students: Usability and Feasibility Study

BACKGROUND

Skill training in nursing education has been highly dependent on self-training because of Korea's high student-faculty ratio. Students tend to have a passive attitude in self-practice, and it is hard to expect effective learning outcomes with traditional checklist-dependent self-practice. Smart glasses have a high potential to assist nursing students with timely information, and a hands-free device does not interrupt performance.

OBJECTIVE

This study aimed to develop a smart glass-based nursing skill training program and evaluate its usability and feasibility for the implementation of self-practice.

METHODS

We conducted a usability and feasibility study with 30 undergraduate nursing students during a 2-hour open lab for self-practice of core nursing skills, wearing smart glasses for visualized guidance. The usability test was conducted using a 16-item self-reporting questionnaire and 7 open-ended questions. Learning satisfaction was assessed using a 7-item questionnaire. The number of practice sessions was recorded, and perceived competency in core nursing skills was measured before and after the intervention. At the final evaluation, performance accuracy and time consumed for completion were recorded.

RESULTS

Smart glass-assisted self-practice of nursing skills was perceived as helpful, convenient, and interesting. Participants reported improved recollection of sequences of skills, and perceived competency was significantly improved. Several issues were raised by participants regarding smart glasses, including small screen size, touch sensors, fogged lenses with masks, heaviness, and heat after a period of time.

CONCLUSIONS

Smart glasses have the potential to assist self-practice, providing timely information at students' own paces. Having both hands free from holding a device, participants reported the convenience of learning as they could practice and view the information simultaneously. Further revision correcting reported issues would improve the applicability of smart glasses in other areas of nursing education.

Head-worn displays and job content: A systematic literature review

Despite the emergence of head-worn displays at work around forty years ago, few studies have appeared about their impact on job content. To investigate this, a systematic literature review was conducted on these devices and job content, defined as job demands and controls. In total, 3481 studies were identified using five scientific databases. After applying selection criteria, reference searches, citation tracking and an in-depth reading, 28 studies were selected for review. Remarkably, the findings of these studies showed contrasting results. Both increases and decreases in job demands and controls were identified. We distinguished across studies two opposite approaches for the deployment of these devices, i.e. a supportive and a directive approach.

MARMA: A Mobile Augmented Reality Maintenance Assistant for Fast-Track Repair Procedures in the Context of Industry 4.0

The integration of exponential technologies in the traditional manufacturing processes constitutes a noteworthy trend of the past two decades, aiming to reshape the industrial environment. This kind of digital transformation, which is driven by the Industry 4.0 initiative, not only affects the individual manufacturing assets, but the involved human workforce, as well. Since human operators should be placed in the centre of this revolution, they ought to be endowed with new tools and through-engineering solutions that improve their efficiency. In addition, vivid visualization techniques must be utilized, in order to support them during their daily operations in an auxiliary and comprehensive way. Towards this end, we describe a user-centered methodology, which utilizes augmented reality (AR) and computer vision (CV) techniques, supporting low-skilled operators in the maintenance procedures. The described mobile augmented reality maintenance assistant (MARMA) makes use of the handheld’s camera and locates the asset on the shop floor and generates AR maintenance instructions. We evaluate the performance of MARMA in a real use case scenario, using an automotive industrial asset provided by a collaborative manufacturer. During the evaluation procedure, manufacturer experts confirmed its contribution as an application that can effectively support the maintenance engineers.

Awareness of the real-world environment when using augmented reality head-mounted display

Augmented reality (AR) systems are becoming common tools in industrial workplaces. However, factory workers are still concerned about whether head-mounted display (HMD)-based AR systems distract their awareness of the environment and therefore pose safety risks. The purpose of this study was to assess users' experience of real-world awareness when using an AR system. 19 study participants played a wooden block logic game in a laboratory with three different setups: real, AR and virtual reality (VR). Based on this study, it can be concluded that HMD-based AR systems do not decrease users' awareness of their surroundings if the virtual content is minimal and the task is done while seated. However, it was seen that more research in this area with more interactive virtual content is required. This study is an important step in understanding how AR may affect future work in industrial and safety-critical environments.

Performance and Usability of Smartglasses for Augmented Reality in Precision Livestock Farming Operations

In recent years, smartglasses for augmented reality are becoming increasingly popular in professional contexts. However, no commercial solutions are available for the agricultural field, despite the potential of this technology to help farmers. Many head-wearable devices in development possess a variety of features that may affect the smartglasses wearing experience. Over the last decades, dairy farms have adopted new technologies to improve their productivity and profit. However, there remains a gap in the literature as regards the application of augmented reality in livestock farms. Head-wearable devices may offer invaluable benefits to farmers, allowing real-time information monitoring of each animal during on-farm activities. The aim of this study was to expand the knowledge base on how augmented reality devices (smartglasses) interact with farming environments, focusing primarily on human perception and usability. Research has been conducted examining the GlassUp F4 smartglasses during animal selection process. Sixteen participants performed the identification and grouping trials in the milking parlor, reading different types of contents on the augmented reality device optical display. Two questionnaires were used to evaluate the perceived workload and usability of the device. Results showed that the information type could influence the perceived workload and the animal identification process. Smart glasses for augmented reality were a useful tool in the animal genetic improvement program offering promising opportunities for adoption in livestock operations in terms of assessing data consultation and information about animals.

Scheduling algorithm for the picture configuration for secondary tasks of a digital human–computer interface in a nuclear power plant

Secondary tasks of a digital human–computer interface in a nuclear power plant increase the mental workloads of operators and decrease their accident performance. To reduce the adverse effects of secondary tasks on operators, a picture configuration scheduling algorithm of secondary tasks is proposed. Based on the research background and operator interviews, a scheduling algorithm process is established, and variables and constraint conditions of the scheduling process are defined. Based on the scheduling process and variables definitions, this article proposes a picture feature extraction method, a method for counting identical keywords, an arrangement method of queues in a buffer pool and a picture configuration scheduling algorithm of secondary tasks. The results of simulation experiments demonstrate that the algorithm realizes satisfactory performance in terms of the number of replacements, the average waiting time, and the accuracy.

Impacts of Wearable Augmented Reality Displays on operator performance, Situation Awareness, and communication in safety-critical systems

Wearable Augmented Reality Displays (WARDs) present situated, real-time information visually, providing immediate access to information to support decision making. The impacts of WARD use on operator performance, Situation Awareness (SA), and communication in one safety-critical system, marine transportation, were examined in a real-time physical simulator. WARD use improved operator trackkeeping performance, the practice of good seamanship, and SA, although operator responsiveness decreased. WARD users who used more closed-loop communication and information sharing showed improved threat avoidance, suggesting that operators can avoid accidents and failure through WARD use that promotes sharing and confirming information. WARD use also promoted information source diversity, a means of developing requisite variety. These operational impacts are important in safety-critical settings where failures can be catastrophic.