Aerospace Medicine and Biology: A continuing bibliography with indexes, supplement 187

This supplement to Aerospace Medicine and Biology lists 247 reports, articles and other documents announced during November 1978 in Scientific and Technical Aerospace Reports (STAR) or in International Aerospace Abstracts (IAA). In its subject coverage, Aerospace Medicine and Biology concentrates on the biological, physiological, psychological, and environmental effects to which man is subjected during and following simulated or actual flight in the earth's atmosphere or in interplanetary space. References describing similar effects of biological organisms of lower order are also included. Emphasis is placed on applied research, but reference to fundamental studies and theoretical principles related to experimental development also qualify for inclusion. Each entry in the bibliography consists of a bibliographic citation accompanied in most cases by an abstract

A Comparison Between Functional and Traditional Interface Displays in Support of Console Operator Performance and Workload

In the petrochemical industry, schematic interfaces have been traditionally used as the main interface for console operators to monitor activities. There is limited research in this industry investigating alternative interface types to better support console operator’s decisions during alarm management. Furthermore, even less of that research includes eye-tracking as a measure for console operator situation awareness (SA). This research aimed to investigate an alternative interface, called a functional interface, in its level of support of console operator situation awareness, accuracy, subjective workload, and average response time. Additionally, eye-tracking was incorporated to explore its value as measure for situation awareness on interfaces in petrochemical control rooms. This research used a 2x3 factorial design to explore the effects of interface type (schematic vs. functional) and complexity level (easy, medium, and hard) in engineering students at Louisiana State University (LSU). The experiment involved three 30 minute simulations on either the schematic or the functional interface design of a main overview display that is typically seen in a refinery. The dependent variables included SA, subjective workload, accuracy, average response time, and eye fixation percentages for certain areas of interest (AOI). The mixed model analyses showed that there were no significant differences between interface types for any dependent variables except for the eye fixations in non-AOIs during non-alarm times. Participants spent significantly less time looking at non-AOIs during non-alarm times for the functional interface than the schematic. For complexity levels, there were no significant differences except for average response times. Average response times were were significantly higher for the medium level then the easy or hard levels. Also, the eye-tracking results showed that participants spent significantly less time in the intended AOIs and non-intended areas on the easy complexity level than the medium or hard. There was a significant positive correlation between the fixation percentages of the intended AOI during alarm times and SA1, indicating that eye-tracking was able to capture participants noticing process deviations during the simulation. Eye-tracking appears to be a good measure of SA1 among console operators. Overall, this research does not provide evidence that functional interfaces provide more support of console operator SA, workload, or performance

Rearward visibility issues related to agricultural machinery: Contributing factors, potential solutions

As the size, complexity, and speed of tractors and other agricultural self-propelled machinery have increased, so have the visibility-related issues, placing significant importance on the visual skills, alertness, and reactive abilities of the operator. Rearward movement of large agricultural equipment has been identified in the literature as causing not only damage to both machine and stationary objects, but also injuries (even fatalities) to bystanders not visible to the operator. Fortunately, monitoring assistance, while not a new concept, has advanced significantly, offering operators today more options for increasing awareness of the area surrounding their machines. In this research, an attempt is made to (1) identify and describe the key contributors to agricultural machinery visibility issues (both operator and machine-related), and (2) enumerate and evaluate the potential solutions and technologies that address these issues via modifications of ISO, SAE, and DOT standardized visibility testing methods. Enhanced operator safety and efficiency should result from a better understanding of the visibility problems (especially with regard to rearward movement) inherent in large tractors and self-propelled agricultural machinery. Used in this study were nine machines of different types that varied widely in size, horsepower rating, and operator station configuration to provide a broad representation of what is found on many U.S. farms/ranches. The two main rearward monitoring ‘technologies’ evaluated were the machines’ factory-equipped mirrors and cameras that the researchers affixed to these machines. A 58.06 m2 (625 ft2) testing grid was centered on the rear-most location of the tested machinery with height indicators centered in each of twenty-five grid cells. In general, the findings were consistent across all the machines tested—i.e., rather obstructed rearward visibility using mirrors alone versus considerably less obstructed rearward visibility with the addition of cameras. For example, having exterior extended-arm and interior mirrors only, a MFWD tractor with 1,100-bushel grain cart in tow measured, from the operator’s perspective, 68% obstructed view of the grid’s kneeling-worker-height markers and 100% throughout the midline of rearward travel; but when equipped with a rearview camera system, the obstructed area was decreased to only 4%. The visibility models created identified (1) a moderate-positive Pearson r correlation, indicating that many of the obstructed locations of the rearward area affected both mirrors and cameras similarly and (2) a strong-positive Pearson r correlation of kneeling worker height visibility, indicating that mirrors and camera systems share commonality of areas with high visibility (along the midline of travel and outward with greater distance from the rear of the machine, without implements in tow). Of the recommendations coming from this research, the key one is for establishment of engineering standards aimed at (1) enhancing operator ability to identify those locations around agricultural machinery that are obstructed from view, (2) reducing the risk of run-overs through improved monitoring capabilities of machine surroundings and components, and (3) alerting operators and co-workers of these hazardous locations

Nineteenth Annual Conference on Manual Control

No abstract availabl

Aerospace medicine and biology: A continuing bibliography with indexes (supplement 288)

This bibliography lists 190 reports, articles and other documents introduced into the NASA scientific and technical information system in August 1986

Aerospace Medicine and Biology: A continuing bibliography, supplement 191

A bibliographical list of 182 reports, articles, and other documents introduced into the NASA scientific and technical information system in February 1979 is presented

Eleventh Annual Conference on Manual Control

Human operator performance and servomechanism analyses for manual vehicle control tasks are studied

Variability in humans, machines and tasks on whole-body vibration exposures and effects

There are many factors that can influence the effectiveness of any risk management strategy, in the case of whole-body vibration exposure many problems are faced with the quantification of risk, measurement of risk and subsequent risk reduction. The quantification of vibration effects is equally as complex as the quantification of vibration itself. Exposure to whole-body vibration (WBV) causes a distribution of motions and forces within the human body and to complicate matters the transmission of vibration to the body is also dependent on body posture. To-date there has been little attempt to accurately reflect many of the typical postures and vibration environments experienced by operators of earth moving machines in a laboratory setting. The overall aim of the thesis was to determine the variability between humans, machines and task environments in order to provide knowledge to inform improvements in methods of risk management for whole-body vibration exposure. The field measurement phase of the research focused on characterising features of whole-body vibration exposure among operators of earthmoving machines throughout a range of industry sectors. Some of the biggest industries; coal mining, quarries, and construction were targeted to obtain data on the types of machines for which very little was previously available. Research was carried out under real operating conditions to investigate the nature of occupational exposure to whole-body vibration and to determine the causes of variability between measurements. The laboratory phase of the research simulated the conditions of the 'real working environment' observed in the field study in order to examine how twisted non-neutral postures could influence the biomechanical, performance and workload responses of humans. The machines with the greatest vibration emission were generally those that spent most of their time tracking. The worst machine for vibration exposure was a challenger 85D tracked tractor towing a 'hex' attachment. Operators of this machine would exceed the EU Physical Agents Exposure Limit Value in about 2.5 hours. The next most severe earth moving machines were bulldozers and tracked loaders and with long working hours typically observed in industry some of these machines would also exceed the ELV in a working day. The influence of variability between work cycles was found to be a particular problem for the bulldozer and excavator machines, variation between work cycles exceeded the 25% variance limit criteria. If these machines were targeted for a WBV health risk assessment then the measurement durations will need to take account of this variation in the extrapolation to an 8-hour exposure. The operators of these tracked machines were also found to adopt non-neutral twisted postures during reversing manoeuvres. The twisted posture adopted by the bulldozer and tracked loader operators was recreated in the laboratory. Findings demonstrated that operators are likely to be putting their necks in a vulnerable position in the twisted posture due to the large increase in rotational movement at the head during exposure to vibration. Decrements in reaction time performance and increases in workload were also found while individuals were sat in a twisted posture and exposed to vibration.EThOS - Electronic Theses Online ServiceGBUnited Kingdo