Thomas A. Ulrich

The roles of gender, age and cognitive development in children's pedestrian route selection

OBJECTIVE Thousands of American children under the age of 10 years are injured annually as pedestrians. Despite the scope of this public health problem, knowledge about behavioural control and developmental factors involved in the aetiology of child pedestrian safety is limited. The present study examined the roles of gender, age and two aspects of cognitive development (visual search and efficiency of processing) in childrens safe pedestrian route selection. METHODS Measures of cognitive functioning (visual search and efficiency) and selections of risky pedestrian routes were collected from 65 children aged 5-9 years. RESULTS Boys, younger children and those with less developed cognitive functioning selected riskier pedestrian routes. Cognitive functioning also subsumed age as a predictor of risky route selections. CONCLUSIONS Our findings suggest developmental differences, specifically less developed cognitive functioning, play important roles in childrens pedestrian decision making. Directions for future examination are discussed.

A prototyping environment for research on human-machine interfaces in process control use of Microsoft WPF for microworld and distributed control system development

Operators of critical processes, such as nuclear power production, must contend with highly complex systems, procedures, and regulations. Developing human-machine interfaces (HMIs) that better support operators is a high priority for ensuring the safe and reliable operation of critical processes. Human factors engineering (HFE) provides a rich and mature set of tools for evaluating the performance of HMIs, but the set of tools for developing and designing HMIs is still in its infancy. Here we propose that Microsoft Windows Presentation Foundation (WPF) is well suited for many roles in the research and development of HMIs for process control.

Early-Stage Design and Evaluation for Nuclear Power Plant Control Room Upgrades

As control rooms are modernized with new digital systems at nuclear power plants, it is necessary to evaluate operator performance with these systems as part of a verification and validation process. While there is regulatory and industry guidance for some modernization activities, there are no well defined standard processes or predefined metrics available for assessing what is satisfactory operator interaction with new systems, especially during the early design stages. This paper proposes a framework defining the design process and metrics for evaluating human system interfaces as part of control room modernization. The process and metrics are generalizable to other applications and serve as a guiding template for utilities undertaking their own control room modernization activities.

Studying Situation Awareness on a Shoestring Budget: An Example of an Inexpensive Simulation Environment for Theoretical Research

Current situation awareness (SA) experiments typically involve large-scale field studies or simulations with industry experts servings as participants. In addition, however, smaller scale approaches to examining SA can allow researchers to focus on specific theoretical questions that would otherwise be cost prohibitive. The benefits of using a microworld approach to examine SA are presented along with a prototype microworld simulation environment demonstrating a novel example approach to evaluating SA via the change blindness paradigm. The latest iteration of this prototype includes a microworld simulation of a simplified nuclear process control intended for examining cognitive aspects of SA with student participants. The pilot study results provide promise for continued use of this microworld approach and further investigation into novel SA evaluation techniques such as change blindness.

Change Detection for Measuring Attention Allocation: A New Approach for Capturing Situation Awareness

Attention allocation is an important component of situation awareness and is often assessed with eye tracking. A series of pilot studies were performed to examine a novel approach to evaluating attention in complex three dimensional environments that pose challenges to eye tracking methodologies. This novel approach involves integrating change detector objects into an existing interface to assess attention allocation within the interface. Three pilot studies examined the effectiveness of prototype change detector objects in conjunction with a primary manual tracking task. Change detection accuracy and response times were measured between change detectors located at systematically varying distances from the manual tracking task locus of attention. The results provide evidence for this approach to differentiate between interface regions and their associated attention allocation while completing a primary task. Future efforts will focus on examining the effectiveness of these change detectors in assessing attention allocation during a simulated nuclear process task using a microworld simulation environment.

Nuclear Reactor Crew Evaluation of a Computerized Operator Support System HMI for Chemical and Volume Control System.

A Computerized Operator Support System (COSS) functional prototype was developed as an assistive technology for operators. The COSS was implemented as a hybrid control board for the Chemical Volume Control System (CVCS) of a three loop Combustion Engineering pressurized water reactor and implemented full-scope, full-scale, glass top control room simulator. The hybrid control board simulated a modernized control room with both analog and digital instrumentation and control. The digital portions consisted of large digital overview and smaller touch displays, while the analog portion consisted primarily of safety indicators and controls. The glass top nature of the simulator allowed the COSS configuration to be compared to the existing fully analog configuration. A cooperative research and development agreement with a major US utility allowed for two separate licensed three-person crews of commercial reactor operators to evaluate the COSS. The evaluation revealed stylistic issues, operation insights, and design considerations that will guide control room modernization efforts and influence next generation control systems and Human Machine Interfaces.

Rancor: A Gamified Microworld Nuclear Power Plant Simulation for Engineering Psychology Research and Process Control Applications

We demonstrate the development, rationale, and use of a gamified microworld nuclear power plant simulation for engineering psychology research and process control applications. The Rancor microworld was developed to address specific research needs in support of ongoing U.S. nuclear control room modernization efforts. The Rancor microworld serves as a platform for inexpensive cognitive psychology research that would otherwise not be as feasible in typical complex process control research settings. The gamified nuclear power plant simulator is simple enough that untrained, novice participants can quickly learn and control the system. The Rancor microworld is currently configured to support an investigation of attention and situation awareness in nuclear process control is discussed. The Rancor framework is flexible to support rapid modification for addressing research needs related to complex process control.

The Virtual Human Reliability Analyst

This paper introduces the virtual human reliability analyst model (VHRAM). The VHRAM is an approach that automates the HRA process to enable HRA elements to be included in simulations in general and simulation based risk analysis in particular. Inspirations from clinical AI and game development are discussed as well as the possibilities for a VHRAM to be used outside of a simulated virtual twin of a nuclear power plant.

Operator Timing of Task Level Primitives for Use in Computation-Based Human Reliability Analysis

Computation-based human reliability analysis (CoBHRA) provides the opportunity for dynamic modeling of human actions and their impacts on the state of the nuclear power plant. Central to this dynamic HRA approach is a representation of the human operator comprised of actions and the time course over which those actions are performed. The success or failure of tasks is time dependent, and therefore modeling different times at which the operator completes actions helps predict how timing differences affect the human error potential for a given task. To model the operators’ timing variability, Goals, Operators, Methods, and Selection rules (GOMS) task level primitives were developed based on simulator logs of operators completing multiple scenarios. The logs have sufficient detail to determine the timing information for procedure steps and to map the procedure steps into the task level primitives. The task level primitives can then be applied to other procedures that were not evaluated, since they represent generic task level actions applicable to all procedure steps. With these generic task level primitives, untested scenarios can be dynamically modeled in CoBHRA, which expands the usefulness of the approach considerably. An example is provided of a station blackout scenario, which demonstrates how the operator timing of task level primitives can enhance our understanding of human error in nuclear process control.

COSSplay: Validating a Computerized Operator Support System Using a Microworld Simulator

Our computerized operator support system microworld simulator with student operators approach is called COSSplay. COSSplay allows testing of specific interface elements such as alarm visualizations without the constraints of the surrounding nuclear control room elements typically associated with full-scope simulation studies. Approaches like COSSplay are ideal for first principles research in human factors and human-computer interaction. This paper highlights the uses of COSSplay as a complimentary approach to full-scope simulation studies for complex interface design.