Automation design in advanced control rooms of the modernized nuclear power plants

This study evaluated the effects of levels of automation (LOAs) decisions in advanced control rooms of the modernized nuclear power plants. Following advancements in design of digitalized human–system interfaces (HSIs), the roles of human operators have changed significantly. Negative performance and safety consequences may occur as a result of these changes. These problems are viewed as the out-of-the-loop (OOTL) performance problems. This study conducted an experiment to compare the effects of different LOAs under different operating procedures on operating performance. Experimental results indicated that blended decision-making (level 6 LOA) generates the lowest mental workload. Furthermore, the pattern of SA observed in this study is found better SA at intermediate LOA and poorer SA at low level of automation and full automation. Subjective rating results suggest that LOAs distribute the roles of option generation, and selection between human and/or computer servers which significantly impacts automated system performance. This study provides a direction for the HSI designers in nuclear power plants (NPPs). Additionally, based on results obtained by this study, the user interfaces of PCTRAN system and the alarm reset system should be improved to ensure safe operation of NPPs.     

A real-time warning model for teamwork performance and system safety in nuclear power plants

In order to increase system safety and team performance, this study aimed to develop a real-time warning model (RTWM) by assessing team response time, error rates, and mental workload. Toward this goal, the group method of data handling (GMDH) algorithm was applied to physiological indices to predict team performance. Then fuzzy logic, fuzzy inference and linguistic variable sets representing the Team Performance and Safety Index were applied to construct the RTWM. To model the RTWM, experiments were conducted on computer-supported cooperative work (CSCW) in the personal computer transient analyzer (PCTRAN) simulator. The simulator and teamwork are designed to simulate the real tasks of the control room of the Fourth Nuclear Power Plant (FNPP) in Taiwan. In addition, important physiological parameters, the NASA-TLX questionnaire, team response time, and team error rates were collected from 39 participants. The results revealed that there was a significant positive correlation between the error rates of teamwork and the interval of event arrival time. This indicated that a pre-alarm device is necessary because vigilance decreased with time. Moreover, a predictive teamwork performance model applying the GMDH algorithm and the RTWM with a fuzzy inference system was developed in this study. The proposed model can efficiently predict teamwork performance to maintain appropriate mental workload as well as ensure system safety.     

无人机操作主观心理负荷测评与心率数据比较

为探究在无人机实操试验的心理负荷测量中主观量表与心率测评工具的性能,招募14名从未接触过无人机操作的被试者,在参加飞行操作培训后进行4种不同难度的无人机飞行操作情景试验;使用Polar V800监测被试者试验过程中的心率变化,并在试验结束后采用NASA-TLX,MCH,SWAT 3种主观量表进行评分,以比较飞行难度间各指标的性能差异。结果表明:随着难度增大,呈现出主观评分与MEANHR增大,MEANRR减小的趋势;所有测量指标均能区分大部分难度差异,主观量表之间存在正相关性且收敛效度良好,量表评分与绩效表现之间关联性较强;主观量表与心率指标能够对无人机操作中的心理负荷进行有效的测量,这为未来无人机操作心理负荷的预测提供测量基础。     

The Subjective Rating Scales for Measurement of Mental Workload—Thurstonian Scaling

Subjective rating scales for measuring work demands and individual capabilities to cope with work requirements were developed using the Thurstonian procedure. The scales measure six dimensions of mental workload: mental difficulties, feeling of responsibility, awareness of risk, interpersonal conflicts, monotony, and time pressure. Individual scale results make it possible to assess the level of mental workload understood as a relation between the subjective rating of work demands and individual capabilities in each of the six dimensions. Two versions of scales were prepared: classic and modified ones. To assess the level of reliability of the particular scales, 481 participants were examined twice at a 1-month interval. A procedure to prepare scales for the measurement of other dimensions of mental workload is also presented.     

On the subjective experience and correlates of downtime at work: A mixed‐method examination

In the current paper, we studied downtime at work. Downtime represents a unique aspect of work time, as employees have low workload and more discretion about their activities but are still paid to be at work. Despite its prevalence and potentially significant implications for productivity and well‐being, the experience of downtime has not been a focus in the literature. To study this phenomenon, we first used a qualitative method involving 15 focus groups. Results from 95 employees showed that downtime is distinct from formal breaks and withdrawal behavior and is generally a negative subjective experience. Categories of antecedents of experience and downtime activities were classified. Next, to further explore the phenomenon, and based on Study 1 and relevant literature, we proposed several hypotheses and tested them using an experience sampling method. Results from 86 employees (across 5 workdays and 689 data points) indicated that the amount of downtime was negatively related to day level job satisfaction, job performance, and subjective health. The duration of relaxation activities during downtime mitigated the negative effects of downtime on fatigue. The effects of enjoyment level of the activities, job autonomy, work engagement, and boredom proneness were also examined. Implications, limitations, and future research are discussed.     

CREAM失误概率预测法在驾驶舱机组判断与决策过程中的应用

CREAM强调人在生产活动中的绩效输出不是孤立的随机性行为,而是依赖于人完成任务时所处的环境或工作条件,它通过影响人的认知控制模式和其在不同认知活动中的效应,最终决定人的响应行为。在驾驶舱内,机组的绩效输出不仅仅是人的自身行为,还依赖于其完成任务时所处的情景环境,所以CREAM方法能够结合驾驶舱环境对机组的认知差错进行分析。在飞行中,驾驶舱内机组非常重要的一个环节是判断与决策过程,这一过程中包括询问、讨论、确定方案、执行、反馈五个环节。本文将通过分析这五个环节的相互关系及影响,以明确这种讨论过程是减少机组人为差错发生的一种有益方式,然后应用CREAM的预测法对这五个环节进行定量化分析,得出机组判断与决策过程的失误概率,完成对机组认知行为的客观评价,并为以后能够定量化研究驾驶舱内飞行员认知差错提供方法的借鉴。     

We're all in this together…except for you: The effects of workload,performance feedback,and racial distance on helping behavior in teams

We draw from social categorization theory and the actor–observer hypothesis to extend previous research regarding receiving high levels of help from team members. Specifically, we explore how a team member's performance feedback on how they handled a disproportionately heavy share of the team's workload and how their racial distance from the rest of their teammates affect the amount of helping that person receives from their teammates. Results from a laboratory study in which 79 teams worked on a computerized, decision‐making task demonstrated a three‐way interaction between workload, performance feedback, and the racial distance between the feedback recipient and the rest of their teammates. Racially distant negative feedback recipients who had a disproportionately heavy share of their team's workload received less help from teammates than their racially similar counterparts. Copyright © 2012 John Wiley & Sons, Ltd.     

The safety effect of open-median management on one-side widened freeways: A driving simulation evaluation

Introduction: Highway expansions and upgrades are often required to increase road network capacity. The widening of one side of a highway, referred to as ‘one-side widening,’ is sometimes implemented in these highway expansion projects. During one-side widening, to save costs, openings can be configured on existing medians (as opposed to removing the existing medians altogether). The median openings allow vehicles in the outer lanes to enter the inner lanes, but they also raise safety concerns and may require alternate open-median management strategies for traffic authorities. There is little existing research that has evaluated the safety effect of these open-median management strategies. Method: To bridge this gap, this study proposes a procedure that evaluates the safety of open-median management strategies for one-side widened highways. The proposed procedure was implemented through driving simulation experiments on a section of Binlai Freeway in Shandong, China. First, the minimum location requirements for median openings were determined by calculating the short length of the weaving segment. Then, simulation tests were carried out to observe driving performance and workload measures. Results: The results indicate that the procedure successfully evaluates the safety effect of open-median management strategies for one-side widened freeways. It was also found that driving performance and workload are sensitive to the opening length and traffic flow. Conclusions: Therefore, median opening placement should be carefully selected in consideration of not only driving performance and workload but also traffic volume predictions. Practical Applications: The findings in this study can guide open-median management strategies for traffic safety one-side widened highways.     

Team crystallization (SIO2): Dynamic model of team effectiveness evaluation under the dynamic and tactical environment at nuclear installation

Accident management activities at nuclear power plants require concurrent communication, information sharing, team based decision-making and collective actions under tactical and dynamic environments. Team effectiveness under such environments can be characterized as the performance of team situation awareness with hierarchically distributed information and knowledge susceptible to organizational characteristics and communication quality. This paper proposes a team performance model, called a team crystallization model comprising of four elements: state, information, organization, and orientation and its quantification method using a communication process model based on a receding horizon control approach. The team crystallization model is a holistic approach for evaluating team effectiveness in conjunction with team situation awareness considering physical system dynamics and team behavioural dynamics for a tactical and dynamic task at a nuclear power plant. This model provides a systematic measure to evaluate time-dependent team effectiveness or performance affected by multi-agents such as plant states, communication quality in terms of transferring situation-specific information and strategies for achieving the team task goal at a given time, and organizational factors. To demonstrate the applicability of the proposed model and its quantification method, a case study was carried out using the data obtained from a full-scope power plant simulator for 1000 MW(e) pressurized water reactors with four on-the-job operating groups and one expert group who knew accident sequences.     

Team mental models and their potential to improve teamwork and safety: A review and implications for future research in healthcare

The importance of team mental models (TMMs) - team members’ shared and organized understanding of relevant knowledge - for teamwork and team-performance, particularly in high-risk industries, has been recognized for almost two decades. In healthcare, however, systematic investigations on the influence of TMM on teamwork and team-performance had yet to be conducted at the time of this review, despite many authors considering the concept to be useful for medical teams. The lack of measurement procedures appropriate for settings as complex and dynamic as, for example, the operating room, represents a major obstacle for empirical research in healthcare. We systematically reviewed empirical studies on TMMs aiming to identify methods that could be applied in healthcare. In particular, we analyzed the methods used, and situations in which TMMs have been investigated. The reviewed studies were sorted according to task and team characteristics. We discuss the results of this review with regard to characteristics of healthcare teams including anaesthesia teams and teams of ward nurses. Each of these examples represents a distinct teamwork setting (e.g. long- vs. short-lived teams) and hence requires a different approach to TMM measurement (e.g. focus on task-model vs. focus on team-model). Implications for study design, feasible measurement approaches, and questions for future research on TMMs in healthcare are discussed. In sum, our findings highlight the possible significance of TMM research in healthcare and its potential benefits for team-performance and, ultimately, patient safety.     

Multilevel knowledge and team performance

We examined team performance as it was affected by organizationally supported face-to-face and technology-mediated knowledge practices. Guided by an information processing perspective, we demonstrate from a field study of over 250 teams within a global Fortune 100 technology company that team member participation in face-to-face and technology-mediated knowledge practices (e.g., community of practice (CoP) meeting attendance and use of CoP-related technologies, respectively), and team knowledge sharing practices are positively related to individual team member knowledge. We predicted that absorptive capacity would moderate tacit knowledge relationships with team performance, and that transactive memory would moderate explicit knowledge relationships with team performance. We found that the patterns of relationships differed depending on the measure of team performance. The predictions held for absorptive capacity by tacit knowledge on manager-assessed performance, and for transactive memory by explicit knowledge on customer satisfaction. Additionally, there was a significant direct effect, with no moderation, of tacit knowledge on customer satisfaction. We highlight multilevel modeling for team research and argue for joint consideration of organizational and technology practices. Copyright © 2009 John Wiley & Sons, Ltd.     

Predicting work performance in nuclear power plants

Diagnosis and monitoring are the major tasks of an operator in main control room of nuclear power plants (NPPs). The operator’s mental workload influences his/her performance, and furthermore, affects the system safety and operations. This study investigated the operator’s mental workload and work performance of the NPP in Taiwan. An experiment including primary and secondary tasks was designed to simulate the reactor shutdown procedure of the fourth nuclear power plant (FNPP). The performance of the secondary tasks (error rate), subjective mental workload (NASA Task Load Index, NASA-TLX) as well as seven physiological indices were assessed and measured. The group method of data handling (GMDH) was applied to integrate these physiological indices to develop a work performance predictive model. The validity of the proposed model is very well with R² = 0.84 and its prediction capability is high (95% confidence interval). The proposed model is expected to provide control room operators a reference value of their work performance by giving physiological indices. Besides NPPs, the proposed model can be applied to many other fields, e.g. aviation, air transportation control, driving and radar vigilance, etc.     

A multilevel model of emotional skills,communication performance,and task performance in teams

There is increasing research regarding the influence of emotions on teamwork. In this study, we use a multilevel approach to examine how team members' use of emotion‐related skills affects team task performance and communication performance within the team. We measured individual self‐reported emotional skills prior to team formation and then collected peer‐rated individual communication performance and independently rated team task performance eight weeks later. Although there was no influence at the individual level between emotional skills and performance, team‐level emotional skills positively predicted team task performance scores. At the cross level, team‐level emotional skills predicted individual‐level communication performance. These findings emphasize the importance of distinct team emotional skills in shaping both team performance and individual team member performance. Copyright © 2011 John Wiley & Sons, Ltd.     

The relationship between cell phone use and management of driver fatigue: It's complicated

Introduction: Voice communication may enhance performance during monotonous, potentially fatiguing driving conditions (Atchley & Chan, 2011); however, it is unclear whether safety benefits of conversation are outweighed by costs. The present study tested whether personalized conversations intended to simulate hands-free cell phone conversation may counter objective and subjective fatigue effects elicited by vehicle automation. Method: A passive fatigue state (Desmond & Hancock, 2001), characterized by disengagement from the task, was induced using full vehicle automation prior to drivers resuming full control over the driving simulator. A conversation was initiated shortly after reversion to manual control. During the conversation an emergency event occurred. Results: The fatigue manipulation produced greater task disengagement and slower response to the emergency event, relative to a control condition. Conversation did not mitigate passive fatigue effects; rather, it added worry about matters unrelated to the driving task. Conversation moderately improved vehicle control, as measured by SDLP, but it failed to counter fatigue-induced slowing of braking in response to an emergency event. Finally, conversation appeared to have a hidden danger in that it reduced drivers' insights into performance impairments when in a state of passive fatigue. Conclusions: Automation induced passive fatigue, indicated by loss of task engagement; yet, simulated cell phone conversation did not counter the subjective automation-induced fatigue. Conversation also failed to counter objective loss of performance (slower braking speed) resulting from automation. Cell phone conversation in passive fatigue states may impair drivers' awareness of their performance deficits. Practical applications: Results suggest that conversation, even using a hands-free device, may not be a safe way to reduce fatigue and increase alertness during transitions from automated to manual vehicle control.     

To reflect or not to reflect: Prior team performance as a boundary condition of the effects of reflexivity on learning and final team performance

A small but growing body of literature adds to our understanding of the role of team reflexivity (i.e., reflecting upon team functioning) in predicting team performance. Although many studies conclude that reflexivity is an asset for teams, the contingencies of team reflexivity have received far less research attention. In this respect, we argue that team reflexivity may be especially helpful for teams with relatively low performance. Teams that are reflexive tend to learn from previous mistakes, errors, and group processes, which in turn will improve the performance of the team. We propose that this relationship will most likely positively affect learning and final team performance under conditions of relatively poor prior performance. When a team is doing relatively well, the relationship between reflexivity and final team performance will be less clear, as reflexivity and learning is less needed. In a longitudinal study (N = 73 teams), we found support for this idea. As predicted, results indicated that this interaction between team reflexivity and initial team performance on future performance was mediated by team learning. We outline how these findings are important for our understanding of the contingencies of team reflexivity and team performance dynamics. Copyright © 2012 John Wiley & Sons, Ltd.     

增强机组监控技能,确保飞行安全

良好的监控技能对确保飞行安全 ,预防飞行事故发生有十分重要的作用。但由于多方面原因 ,当前的飞行机组监控工作还存在不少问题 ,并成为多起飞行事故主要原因之一。笔者从四方面 ,对民用航空飞行中缺乏良好监控的原因予以分析和说明 :持续有效的监控工作不符合人的本性 ;现行规章制度中未把机组监控技能作为所有机组成员 ,尤其是对辅助操纵者的一项重要任务加以确定 ;现有管理制度与管理观念 ,更多关注行为结果而不是行为发生过程 ;飞行训练中未将其作为重要飞行技能加以训练。笔者强调指出 :采用标准操作程序 ,提高相应飞行阶段的监控技能 ,对不同飞行阶段的工作负荷予以计划和控制、进行工作优先排序 ,加强机组成员间配合 ,在训练中强化监控技能培养等措施 ,有助于改进和增强飞行机组的监控技能 ,确保飞行安全     

No person is an island: The effects of group characteristics on individual trait expression

Although most researchers now espouse a person‐by‐situation interactionist approach, there remains much work to be carried out to fully understand how different features of the environment interact with personality to influence behavior. Thus, this study sought to examine the moderating effects of three group‐level constructs on the relationships between two personality traits (conscientiousness and extraversion) and individual performance and counterproductive behaviors. Specifically, using trait activation theory as an organizing framework, we considered the moderating effects of the following: (i) a previously unexamined construct called core group evaluations (CGEs); (ii) group conscientiousness composition; and (iii) group extraversion composition. Data were obtained from a sample of university football players (N = 225–252 from 40 groups). The results indicated that CGEs moderated the relationships between individual conscientiousness and both performance (subjective) and counterproductive behaviors. Group conscientiousness composition also moderated the relationships between individual conscientiousness and both performance (objective and subjective) and counterproductive behaviors. Lastly, group extraversion composition moderated the relationship between individual extraversion and counterproductive behaviors. These findings highlight the importance of considering a team's CGEs, as well as the personality composition of team members when investigating the effects of conscientiousness and extraversion on individual performance and counterproductive behaviors. Copyright © 2011 John Wiley & Sons, Ltd.     

进近管制员工作进程分类及工作负荷研究

空中交通管制员是管制工作的核心,其工作负荷直接决定该管制空域的飞行容量,而管制员的工作负荷包括可观察的客观负荷和认知理解的主观负荷两类。借鉴国外的MBB,DORA原理,将雷达管制的实施细分为18个工作进程,并通过调查、统计,确定每一工作进程的难度系数;通过多角度摄像方式对成都进近管制室雷达管制席位的工作进行长时间的拍摄,参照划分的工作进程对采集的数据进行深入的统计、分析,采用MMBB方法计算出指挥单架飞机的操作时间和思考时间;确定得出管制单架飞机的工作负荷,以及该空域的容量。     

In-vehicle workload assessment: effects of traffic situations and cellular telephone use

PROBLEM: Assessment of drivers' on-road workload is an important traffic safety consideration. This study was conducted to examine the effects of cellular phone communication on driving performance, with particular emphasis on variations in task demand in different traffic situations. METHOD: Twelve participants were asked to drive on urban roads and motorways with or without concomitant mathematical-addition tests relayed via cellular phone. Measurements included task and driving performance, physiological responses, and compensatory behavior. RESULTS: Analysis of task performance revealed that mean response time was markedly increased (11.9%) for driving on urban roads compared to motorways. The mean driving speed only decreased 5.8% in the presence of phone tasks in comparison to normal driving without distractions. In addition, overall physiological workload increased through compensatory behavior in response to the phone tasks. CONCLUSIONS: Driving with phone use in different traffic environments induced measurable variations in driver workload. IMPACT ON INDUSTRY: When faced with heavy traffic, a greater safety margin is typically adopted, with more lowered driving speed and restricted phone use, and it can be assumed that there is a general trade-off between tasks to preserve driving safety.     

Team mental models and team performance: a field study of the effects of team mental model similarity and accuracy

We conducted a field study of 71 action teams to examine the relationship between team mental model similarity and accuracy and the performance of real‐world teams. We used Pathfinder to operationalize team members' taskwork mental models (describing team procedures, tasks, and equipment) and teamwork mental models (describing team interaction processes) and examined team performance as evaluated by expert team assessment center raters. Both taskwork mental model and teamwork mental model similarity predicted team performance. Team mental model accuracy measures were also predictive of team performance. We discuss the implications of our findings and directions for future research. Copyright © 2006 John Wiley & Sons, Ltd.