Reality-based interaction affecting mental workload in virtual reality mental arithmetic training

ABSTRACT

The concept of digital game-based learning (DGBL) evolves rapidly together with technological enhancements of virtual reality (VR) and smart phones. However, the mental workload (MWL) that VR-training applications demand and motivational qualities originating from user experience (UX) should be identified in order to create effective and enjoyable training/learning challenges that fit with individual users’ capabilities. This study examined the effects of reality-based interaction (RBI) and VR on measures of student motivation and MWL, in a mental arithmetic game for secondary school pupils. In a randomised controlled trial with sixty school children, a mental arithmetic game was tested with three different interaction and two different presentation methods – VR RBI, VR head-mounted-display tapping and tablet flick-gesture. Results found a significant effect of RBI on MWL but no differences in enjoyment of training were found between VR-experience and tablet training-experience. In fact, adding the gaming-context to the mental arithmetic task created an enjoyable, motivating experience regardless of presentation or interaction-style.     

Micro- and macroergonomic changes in mental workload and medication safety following the implementation of new health IT

Health information technology (IT) is a promising way to achieve safer medication management in the delivery of healthcare. However, human factors/ergonomics dictates that in order to make the complex, cognitive work of healthcare delivery safer, health IT must properly support human cognition. This means, for example, that new health IT must reduce, not increase, workload during safety-critical tasks. The present study was the first to quantitatively assess the short- and long-term impact of bar coded medication administration (BCMA) IT on nurses' mental workload as well as on perceived medication safety. One-hundred seventy registered nurses across 3 dissimilar clinical units at an academic, freestanding pediatric hospital in the Midwest US participated in surveys administered before, 3 months after, and 12 months after the hospital implemented BCMA. Nurses rated their external mental workload (interruptions, divided attention, being rushed) and internal mental workload (concentration, mental effort) during medication administration tasks as well as the likelihood of each of three medication safety events: medication administration errors, medication errors on the clinical unit, and clinical unit-level adverse drug events. Clinical unit differences were assessed. Findings generally confirmed the hypothesis that external but not internal mental workload was associated with the perceived likelihood of a medication safety event. Comparisons of mental workload from pre- to post-BCMA revealed statistically significant changes in the critical care unit only. Medication safety appeared to improve over the long term in the hematology/oncology unit only. In the critical care and medical/surgical units, medication safety exhibited short-term improvements that were eliminated over time. Changes in mental workload and medication safety, two classically microergonomic constructs, were deeply embedded in macroergonomic phenomena. These included the fit between the BCMA system and the nature of nursing work, the process of BCMA implementation, and BCMA interactions with concurrent changes occurring in the hospital. Findings raise questions about achieving sustainable performance improvement with health IT as well as the balance between micro- and macroergonomic approaches to studying technology change.Relevance to industryDesigners must consider how technology changes cognitive work, including mental workload. Hospitals and other implementers of technology must ensure that new technology fits its users, their tasks, and the context of use, which may entail tailoring implementation, for example, to specific clinical units. Evaluators must look over time to assess both changes in cognitive work and implementation issues. Healthcare practitioners must also recognize that new technology means a complex transformation to an already complex sociotechnical system, which calls for a macroergonomic approach to design and analysis.     

Bilateral polynomial matrix equations in two indeterminates

Two special cases of the bilateral 2-D polynomial matrix equationDU +VN=C whenC=I andC=I with being a -stable 2-D polynomial, which are related respectively to deadbeat and asymptotic control problems of 2-D systems, are first considered. By generalizing the concepts of factor coprimeness, zero coprimeness and zero skew primeness in the 2-D polynomial ring to the ring of causal -stable 2-D rational functions, a constructive solution of these two problems mentioned is proposed. Based on these results, we derive a solvability condition for the bilateral equiation whereC is a general 2-D polynomial matrix. The general solutions are investigated as well.     

The ability of eye-tracking metrics to classify and predict the perceived driving workload

Traffic safety is directly related to the mental and physical condition of the driver. Performing regular secondary tasks while driving is an additional activity that dissipates attention and adds to the drivers' workload. Identifying driver fatigue and workload based on gaze behavior is one way to ensure a safe driving experience. The purpose of this paper is to classify and predict driving perceived workload using a set of eye-tracking metrics (gaze fixation, duration, pointing, and pupil diameter). The ability of eye-tracking metrics to predict driving workload has been investigated. As a result, frustration, performance, and temporal load showed a correlation with gaze metrics. Gaze point, duration, fixation, and pupil diameter significantly influence driving workload.Relevance to industry: Results will supply the specialists in eye-tracking/sensor technologies and traffic safety with new knowledge to improve the design of the driving performance and safety monitoring systems and efficiency of the driving process.     

Advanced concepts flight simulation facility

The cockpit environment is changing rapidly. New technology allows airborne computerised information, flight automation and data transfer with the ground. By 1995, not only will the pilot's task have changed, but also the tools for doing that task. To provide knowledge and direction for these changes, the National Aeronautics and Space Administration (NASA) and the Lockheed-Georgia Company have completed three identical Advanced Concepts Flight Simulation Facilities.

Many advanced features have been incorporated into the simulators — e g, cathode ray tube (CRT) displays of flight and systems information operated via touch-screen or voice, print-outs of clearances, cockpit traffic displays, current databases containing navigational charts, weather and flight plan information, and fuel-efficient autopilot control from take-off to touchdown. More importantly, this cockpit is a versatile test bed for studying displays, controls, procedures and crew management in a full-mission context. The facility also has an air traffic control simulation, with radio and data communications, and an outside visual scene with variable weather conditions. These provide a veridical flight environment to evaluate accurately advanced concepts in flight stations.     

Validation of a task demand measure for predicting mental workloads of physical therapists

The purpose of this study is to validate an analytical method in assessing demanded mental workloads for physical therapists, and to discuss its possible ergonomics implications on the design of healthcare working systems in which physical therapists are considered as the users. A task analysis was first used to understand the operation steps of three identified physical therapies. Then, the McCracken–Aldrich technique was applied to assign ratings of mental workload demanded for performing each step of the therapies. Finally, the assigned ratings were validated by the analysis of correlation with the answers of the NASA-TLX questionnaire collected from seventeen physical therapists in the rehabilitation center of a university-affiliated hospital. Results showed that the proposed McCracken–Aldrich technique was suitable as an analysis tool for predicting metal workloads of physical therapists. Some possible implications about the information provision and user interface design for reducing therapists' mental workloads on current therapy operations were discussed.Relevance to industryResults of this paper are expected to contribute the research and development in healthcare industry on its system design and workflow analysis.     

造船龙门起重机大车纠偏控制系统的设计与应用

造船龙门起重机随着造船业的迅速发展也跟着快速发展起来。在大车行走过程中,由于龙门起重机的刚腿和柔腿之间的跨距较大,因此要求刚腿和柔腿的位移要始终保持一致,如果偏差过大则会造成大车偏斜运行等严重后果。本文结合软硬件的设计,详细介绍了大车纠偏控制系统从位置检测到位置闭环控制是如何实现大车的实时纠偏。     

一种改进的文档图像倾斜检测算法

在分析现有倾斜检测算法基础上,提出一种改进的文档图像倾斜检测算法。该算法首先对文档图像进行图像增强、去噪和二值化处理,然后提取边界线、计算每条边界线的角度,最后计算加权平均得到文档图像的倾斜角度。通过在计算每条边界线的角度过程中引入LMS算法。改进的算法提高了原算法的精确度、稳定性和适应性。实验表明,改进的方法有效可行。     

桥面铺面防水粘结层胶结材料洒布量的确定方法

为确定桥面铺面防水粘结层胶结材料洒布量,采用橡胶沥青和两种典型的沥青混合料,通过设计直向剪切试验和斜向剪切试验研究桥面防水粘结层的力学性能,分析不同因素对于防水粘结层剪切性能的影响．试验结果表明,加载速率的提高,粘结层最大剪切应力有呈线性增大的趋势;采用不同温度的对比试验,同样发现随温度的升高,其抗剪切能力显著衰减．可以通过剪切试验的剪应力和变形能两个指标评价其剪切性能．     

基于生理振动分析的手机用户身份识别

为保护手机用户的个人信息,对用户进行身份识别认证,提出一种生物识别方法。利用智能手机内置的传感器,采集人体的生理振动信息;通过对采集数据进行去重力等预处理,提取均值、方差、能量、峰度、偏度等特征指标,利用z‐score方法进行标准化处理;进行分类器设计,得出分类器的查准率、误检率等评价指标。分析60组不同用户的生理振动数据,分析结果表明,该分类器的查准率最高可达98?33％。