考虑脑力负荷的模拟手工装配作业实验研究

目的为了减少员工装配作业时由于任务切换导致绩效下降的影响,探究员工在4种任务切换情境下手工装配作业的绩效表现与脑力负荷变化。方法采用复杂性与相似性(2×2)因素的交替任务切换范式,通过乐高模型装配,开展任务重复与任务切换的模拟手工装配作业实验。分析被试的行为绩效指标(错误率、反应时间(RT)、平均装配时间)和任务切换前后脑电(EEG)指标的变化及其差异。结果不同类型任务切换不会导致被切换任务错误率上升;复杂不相似任务切换时,切换任务错误率显著高于简单任务切换,反应时间显著高于另外3种任务切换;复杂相似任务切换时,脑力负荷处于平稳状态,其他3种均导致员工脑力负荷增大。结论 4类指标赋予相同权重情况下,任务切换类型的优选方案依次为复杂相似型、简单不相似型、简单相似型、复杂不相似型。     

基于过程识别的认知性VDT监控作业绩效形成机理

为提高认知性VDT监控作业绩效，运用隐马尔可夫模型解析作业过程并分析绩效形成机理。构建认知性VDT监控作业HMM概念模型，运用E-prime设计实验任务，运行ErgoLAB实验平台采集被试绩效及眼动数据，训练HMM参数并进行可信性验证，使用Viterbi算法将观察序列解码为认知动素链，分析认知动素链特征与作业绩效之间的关系，探究绩效形成机理。结果表明，认知性VDT监控作业过程可以用认知动素链表征，作业者和任务的不同会导致认知动素链的差异；结构相同情况下，认知动素链越长作业绩效越差；长度相同情况下，认知动素链结构和动素类型的差异会影响作业绩效。     

塔式起重机驾驶员的操控培训方法与任务复杂度的关系

为研究塔式起重机驾驶员不同的培训方法对操作绩效的影响,以及不同的培训方法和操控任务复杂度之间的关系,利用塔式起重机虚拟仿真实验平台,设计了训练方法和任务复杂度等两因素三水平的实验,通过实验验证了:1)采用不同的培训方法对操作绩效产生显著性的影响;2)不同复杂度操控任务应该采用不同的培训方法。     

虚拟现实中多通道信息呈现方式的认知负荷定量研究

目的 针对虚拟现实体验系统中的不同信息呈现方式,对使用者交互效率影响难以确定及量化的问题,进行定量研究。方法 通过搭建虚拟现实场景,以信息呈现通道的类别与数量作为变量,展开跟踪–检测响应双任务实验;通过记录任务行为数据中的跟踪误差和响应时间,以及生理数据中的瞳孔直径大小,分析并讨论在不同通道刺激影响因素下的实验中,任务绩效及眼动生理反应变化规律;同时结合主观负荷评价数据,建立了基于BP神经网络的多通道认知负荷模型,以认知负荷作为交互效率的综合评价指标,量化任务执行效率。结果 信息呈现的通道类别及其数量对任务效率均有显著的影响。结论 信息呈现通道数量与任务绩效及生理反应呈一定程度的正相关;多个任务使用相同通道呈现信息会损害所有任务的绩效,增加认知负荷。模型输出的负荷值与主观认知负荷评估值吻合较好,相对误差为8.2%,验证了其有效性。     

《中断风险与供应链绩效模型研究》

该书为了明确中断风险对供应链网络整体绩效的影响,对中断风险下不同复杂程度的供应链网络进行建模,并通过相应的绩效分析方法对中断风险的影响进行定量分析研究,在此基础上讨论中断风险的有关管理问题。该书应用模型对串型和装配型供应链网络进行建模,并分别     

心理负荷对驾驶员刺激检测的影响

复杂的道路交通状况以及智能车机交互系统会增加驾驶员的心理负荷，降低其对刺激的检测绩效，从而增加驾驶安全风险、导致事故发生。本文从负荷理论出发，综述了心理负荷对于驾驶员刺激检测的影响，以及其它因素的调节作用。(1)不同类型的心理负荷会对驾驶条件下刺激检测造成一定影响。一方面，不管在单通道还是跨通道条件下，高知觉负荷都会降低驾驶任务中的刺激检测绩效，主要通过影响驾驶员注意选择发生的阶段。另一方面，认知负荷也会影响驾驶员的刺激检测，主要通过影响驾驶员内源性注意的执行控制能力从而决定驾驶员对于刺激检测的次序。(2)心理负荷对驾驶员刺激检测的影响还会受到驾驶员年龄差异、对刺激检测的反应方式以及特殊刺激等其它因素的调控。未来可从心理负荷机制的角度研究各因素对驾驶员刺激检测产生的影响，以及各因素之间可能存在的交互作用。     

基于KLEE和模糊综合评价的作业者认知能力评估

作业者的认知能力是影响作业绩效的重要因素,目前缺少对作业者认知能力的量化评估方法。为解决该问题,针对作业者认知能力评估具有多因素、模糊性等特点,本文综合运用古林法和模糊综合评价法,首先确定认知因素的重要性权值,在明确评价等级的基础上,构建认知因素的隶属度矩阵,最终建立了一种定性分析和定量分析相结合的个体认知能力评估模型。结合作业特点及要求,该模型可对影响作业绩效的人的认知能力进行准确评估。     

基于视觉生理反应指标的工业系统人机界面出错因子提取研究

为了降低用户在操作数字化仪控系统交互界面的认知负荷，降低用户在操作数字化仪控系统交互过程中的出错率，进行眼动追踪实验。实验以核电厂监控任务界面为样本，运用凝视与扫视生理反应指标，对数字化仪控系统交互界面的信息特征布局进行探究。基于对实验数据的结果分析得出，用户在数字化仪控系统交互界面视觉认知过程中，会产生信息疏漏、误读/误判等出错因子，并通过提取用户在操作过程中产生的出错因子，为数字化仪控界面的设计提供参考依据。基于设计认知过程中出错因子的交互界面设计对减少任务的出错率和提升交互界面的认知绩效具有一定的参考价值。     

面向复杂装配任务的脑力负荷综合评估方法

复杂装配作业脑力负荷过高会降低装配绩效和质量,甚至引发安全事故。因此,对装配任务脑力负荷进行准确测量与评估,确定作业人员的脑力负荷水平,是生产系统优化的重要依据。本文针对复杂装配任务的脑力负荷评估问题,设计了基于Lego积木模拟的装配任务实验,使用主观测量法、绩效测量法和生理测量法采集了27项指标数据,分析了各项数据对脑力负荷变化的敏感性,发现绩效测量指标、主观测量指标、注视次数、总注视时间、扫视次数、总扫视时间和平均瞳孔直径这7项指标是复杂装配任务脑力负荷的有效测量指标。基于有效测量指标,采用BP (back propagation)神经网络和贝叶斯线性判别两种建模方法,构建了装配任务脑力负荷综合评估模型。研究结果表明,使用因子分析将7维指标转化为二维综合指标作为主成分输入,使用归一化共轭梯度法为训练算法的BP神经网络模型是装配作业脑力负荷的最佳综合评估模型,其判别准确率达到84.80%。本文提出的脑力负荷测量与评估方法可为装配作业脑力负荷评定和优化提供参考依据。     

认知性VDT持续监控作业绩效与脑力负荷的关系研究

目的认知性VDT持续监控作业已成为当今社会的主要劳动模式,研究作业过程中人的绩效与脑力负荷之间的关系,提高作业系统绩效。方法结合N-back任务范式和CPT任务范式,设计两因素控制模式,模拟认知性VDT持续监控作业,30名被试接受模拟作业。结果基于时间持续的"累积性脑力负荷"对作业绩效的影响大于基于信息处理量的"绝对脑力负荷"对作业绩效的影响。结论相对于作业任务的优化设计,作业制度的合理安排对认知性VDT持续监控作业绩效的提高更加有效。     

Identifying cognitive complexity factors affecting the complexity of procedural steps in emergency operating procedures of a nuclear power plant

In complex systems such as a nuclear and chemical plant, it is well known that the provision of understandable procedures that allow operators to clarify what needs to be done and how to do it is one of the requisites to secure their safety.As a previous study in providing understandable procedures, the step complexity (SC) measure that can quantify the complexity of procedural steps in emergency operating procedures (EOPs) of a nuclear power plant (NPP) was suggested. However, the necessity of additional complexity factors that can consider a cognitive aspect in evaluating the complexity of procedural steps is raised.To this end, the comparisons between operators' performance data measured by the form of a step performance time with their behavior in carrying out the prescribed activities of procedural steps are conducted in this study. As a result, two kinds of complexity factors (the abstraction level of knowledge and the level of engineering decision) that could affect an operator's cognitive burden are identified.Although a well-designed experiment is indispensable for confirming the appropriateness of the additional complexity factors, it is strongly believed that the change of operators' performance data can be more authentically explained if the additional complexity factors are taken into consideration.     

Comparing the complexity of procedural steps with the operators' performance observed under stressful conditions

In this study, to clarify the appropriateness of the step complexity (SC) measure, step performance time data are empirically collected under stressful conditions, and then they are compared with the SC scores. As for the result, when the operators have to accomplish their tasks using the procedures, it is found that there is a statistically meaningful correlation between the SC scores and the operators' performance data under stressful conditions. Therefore, although the data used in this study are not obtained from designed experiments but from empirical observations, it is quite positive to expect that the SC measure could be a useful method to scrutinize the operators' performance under stressful conditions. It is also expected that the SC measure can be used to improve both the procedures and the quality of the emergency training because the complicated tasks that need careful consideration are effectively distinguished by it.     

Proactive assessment of basic complexity in manual assembly: development of a tool to predict and control operator-induced quality errors

A major challenge for manufacturing companies today is to manage a huge amount of product variants and build options at the same time in manufacturing engineering and in production. The overall complexity and risk of quality errors in manual assembly will increase placing high demands on the operators who must manage many different tasks in current production. Therefore, methods for decreasing and controlling assembly complexity are urgent because managing complex product and installation conditions will result in distinct competitive advantages. The objective of this paper is to present a method for predictive assessment of basic manual assembly complexity and explain how included complexity criteria were arrived at. The verified method includes 16 high complexity and 16 low complexity criteria to aid designers in preventing costly errors during assembly and create good basic assembly conditions in early design phases of new manufacturing concepts.     

Reducing the disruptive effects of interruption: A cognitive framework for analysing the costs and benefits of intervention strategies

Interruptions are ubiquitous, and they can lead to disastrous consequences. The goal of this paper is to describe remedies that have been proposed to reduce the disruption caused by interruptions based on an understanding of how principles of human cognitive processing bear on the sequence of events that take place during an interruption. We show that interruptions tap disparate cognitive operations, from attention to decision making to memory. We illustrate how these cognitive processes can lead to interruption-induced errors, and how they can help in understanding potential problems with remedies that have been proposed to ameliorate those effects. We present a framework in which the load imposed by the task and the cost of an error suggests the types of solutions that should be considered for a given domain. We then discuss the implications of this approach for understanding and reducing the negative effect of interruptions in transportation domains.     

The operators' non-compliance behavior to conduct emergency operating procedures—comparing with the work experience and the complexity of procedural steps

Many kinds of procedures have been used to reduce the operators' workload throughout various industries, such as in the aviation, the chemical and the nuclear industry. It is remarkable that, however, significant portion of accidents or incidents was caused by procedure related human error due to non-compliance of procedures.In this study, to investigate the operators' non-compliance behavior, emergency-training records were collected using a full scope simulator. And three types of the operators' behavior (such as strict adherence, skipping redundant actions and modifying action sequences) observed from collected emergency training records were compared with both their work experience and the complexity of procedural steps.As the results, three remarkable relationships are obtained. They are: (1) the operators who have an intermediate work experience seem to frequently adopt non-compliance behavior to conduct the procedural steps, (2) the operators seem to frequently adopt non-compliance behavior to conduct the procedural steps that have an intermediate procedural complexity, and (3) the senior reactor operators seem to accommodate their non-compliance behavior based on the complexity of procedural steps. Therefore, it is expected that these relationships can be used as meaningful clues not only to scrutinize the reason for non-compliance behavior but also to suggest appropriate remedies for the reduction of non-compliance behavior that can result in procedure related human error.     

The effects of brief visual interruption tasks on drivers’ ability to resume their visual search for a pre-cued hazard

Driver visual distraction is known to increase the likelihood of being involved in a crash, especially for long glances inside the vehicle. The detrimental impact of these in-vehicle glances may carry over and disrupt the ongoing processing of information after the driver glances back up on the road. This study explored the effect of different types of visual tasks inside the vehicle on the top-down processes that guide the detection and monitoring of road hazards after the driver glances back towards the road. Using a driving simulator, 56 participants were monitored with an eye tracking system while they navigated various hazardous scenarios in one of four experimental conditions. In all conditions, a potential hazard was visible 4–5 s before the driver could strike the potential hazard were it to materialize. All interruptions were exactly two seconds in length. After the interruption the potential hazard again became visible for about a half-second after which the driver passed by the hazard. The nature of the in-vehicle visual interruption presented to the participants was varied across conditions: (1) Visual interruptions comprised of spatial, driving unrelated, tasks; (2) visual interruptions comprised of non-spatial, driving unrelated, tasks; (3) visual interruptions with no tasks added; and (4) no visual interruptions. In the first three conditions drivers glancing on the forward roadway was momentarily interrupted (either with or without a task) just after the potential hazard first became visible by the occurrence of an in-vehicle task lasting two seconds. In the last condition (no interruptions) the driver could not see the potential hazard after it just became visible because of obstructions in the built or natural environment. The obstruction (like the interruption) lasted for two seconds. In other words, across all conditions the hazard was visible, then became invisible, and finally became visible again. Importantly, the results show that the presence of an interruption (as opposed to an obstruction) negatively impacted drivers’ ability to anticipate the potential hazard. Moreover, the various types of interruptions had differential effects on hazard detection. The implications of this study for the design of in-vehicle displays are discussed.     

A study on the development of a task complexity measure for emergency operating procedures of nuclear power plants

In this study, a measure called task complexity (TACOM) that can quantify the complexity of tasks stipulated in emergency operating procedures of nuclear power plants is developed. The TACOM measure consists of five sub-measures that can cover remarkable complexity factors: (1) amount of information to be managed by operators, (2) logical entanglement due to the logical sequence of the required actions, (3) amount of actions to be accomplished by operators, (4) amount of system knowledge in recognizing the problem space, and (5) amount of cognitive resources in establishing an appropriate decision criterion. The appropriateness of the TACOM measure is investigated by comparing task performance time data with the associated TACOM scores. As a result, it is observed that there is a significant correlation between TACOM scores and task performance time data. Therefore, it is reasonable to expect that the TACOM measure can be used as a meaningful tool to quantify the complexity of tasks.     

Assessment of manual assembly complexity: a theoretical and empirical comparison of two methods

There are several theoretical methods for assessment of assembly complexity but there are few practically applicable methods. One of the methods, CompleXity Index (CXI), aims at assessing operators’ perception of manual assembly complexity in running production. Another recently developed method, Basic Assembly Complexity (CXB) is intended for predictive assessment of basic manual assembly complexity in early product and production development. Both CXI and CXB aim to improve assembly conditions for operators, reduce assembly-related errors and the costs for corrective measures as well as increase assembly quality although in different ways and at different organisational levels and life cycle stages. The purpose of this study was to compare the two methods to obtain feedback and learn from operators experience in order to develop better predictive assessment criteria. The method comparison showed that about 50% of the CXB assessment approaches were similar to CXI but other covered different aspects. In comparison of the complexity values of the methods no significant results were obtained. However, some CXI issues that were not taken into account in CXB should be considered. CXB and CXI could be used in conjunction but further assessment criteria are probably needed.