bluuebunny/crossref_metadata_2025_split huggingface dataset:
Prediction of Target Detection Thresholds on the Basis of Physiological Considerations
Authors: Bernstein Arthur 
Published: January 2012

This paper presents a physiological math model which predicts the liminal contrast required to detect a target as a function of target size, background brightness and exposure time. The model is based on the premise that target detection occurs when the difference in response of cells across a target/background brightness contour is greater than some threshold. This premise is supported by recent physiological and psycho-physical measurements. A logical “wiring diagram” for the retina is conceived which resembles the actual anatomy of the retina. The photo-receptor cells, bipolar cells and ganglion cells in the model are given simple mathematical response functions. The target detection requirement for a minimum threshold response difference across a contour is used to develop a mathematical expression of threshold target brightness as a function of background brightness. There are two major parameters in the expression for threshold target brightness: 1) Photo-receptor sensitivity to incident luminance, 2) The threshold response difference required for target detection. The expression for threshold target brightness fits the experimental data well. The model is expanded to explain the variation of the sensitivity and threshold parameters with target size and exposure time. The resulting model is self-consistent and closely agrees with the experimental data for background luminance levels of less than one foot lambert and exposure times less than .1 sec. The results presented in this paper indicate that a coupling of psycho-physical measurements with physiological and anatomical findings leads to both a greater understanding of the physiological processes involved and a more powerful formulation of the psycho-physical results.
A Study of Moving Base Simulation Motion Cues Utilizing Washout Technique
Authors: Kirkpatrick Mark , Shields Nicholas , Brye Ronald , Vinz Frank L. 
Published: January 2012

The present study was conducted to derive data on non-visual motion thresholds utilizing washout technique, and to develop specific threshold values for use as washout parameters. It describes the results of acceleration detection studies carried out using the NASA MSFC General Purpose Simulator which provides six degree-of-freedom cab motion. A series of experiments was performed to test the hypothesis that constant velocity visual cues might suppress non-visual deceleration sensitivity. The psychophysical method employed was the forced-choice procedure which theoretically yields a pure sensitivity measure. The MSFC General Purpose Simulator was programmed to provide velocity ramps in three axes – pitch, fore–aft translation, and vertical translation. Data were collected with and without a constant velocity visual input. Comparison of the current results with classical data suggested significantly greater sensitivity of the human observer to fore-aft accelerations than has generally been reported, sensitivity tending to depend on motion direction and sign of velocity change.
Perceived versus Actual Value of Color-Coding
Authors: Karner Carl 
Published: January 2012

Color-coding has become a widely-used method of information input coding. Unfortunately, little is known regarding general statements concerning under what conditions color-coding will facilitate performance. For this reason, a decision is often made on the basis of judgment if empirical data is not available. The present study is designed to examine performance in a particular short-term memory task and to assess the actual value of color-coding in the task. This actual value is then compared to the participants' judgments of the value of color-coding in that task. The task required the subject to keep track of the current state of each of several variables. One group used a color-coding system while a second group did not. The results showed performance to be significantly better without color-coding; however, all subjects from each group in a post-test interview that they felt that color-coding would be beneficial. The implication is that humans may have rather poor insight regarding the facilitating effects of color-coding.
Hours of Work and Shiftwork
Authors: Rutenfranz Joseph , Colquhoun W. Peter , Knauth Peter 
Published: January 2012

First the time elements of a working day, the duration of working time and the time positioning of working time are treated under ergonomical aspects. Second the reasons for shiftwork, different types of shift work as well as effects on health and on family and social life are discussed. Finally the following physiological criteria for optimal shift-schedules are presented: (1) Single night shifts are better than consecutive night shifts. (2) At least 24 hours free time should be allowed after each night shift. (3) The cycle of a shift system should not be too long. (4) The length of the shift should be related to the type of work. (5) In connection with continuous shift work as many free weekends as possible should be arranged.
Generic Man-Computer Dialogue Specification: An Alternative to Dialogue Specialists
Authors: Pew Richard W. , Rollins Ann M. , Williams George A. 
Published: January 2012

It has long been argued that man-computer dialogues should be written by user-oriented human factors specialists rather than by systems designers who were once programmers and who tend to think like programmers. The difficulty is that very few human factors specialists have access to the dens of systems designers and even when their usefulness is recognized there are not enough such specialists to meet the need. This paper will report on an alternative procedure in which the human factors input is made at the stage at which system planning is under way, when system characteristics are sufficiently well defined that it is possible to write a dialogue specification, but before systems designers have begun to write dialogues. If this specification is effective, it will give the designer freedom to do what he does best, but will do it within predefined constraints that will promote the development of an effective interactive system. In conjunction with the development of a large-scale man-computer system proposed by the Agricultural Stabilization and Conservation Service such a set of dialogue specifications was written. The specifications would permit several system design teams to work independently, but produce dialogue that is relatively uniform from subsystem to subsystem and that meets standards for good human factors design. The steps undertaken to create the specification will be described together with selected samples of the kind of dialogue that may result.
Vibration Ride Comfort Criteria
Authors: Dempsey Thomas K. , Leatherwood Jack D. 
Published: January 2012

This paper presents results obtained from a test program being conducted at Langley Research Center to develop an empirical model for predicting passenger comfort responses to multiaxis vibrations. The specific results contained in this paper are restricted to a description and understanding of human response to complex vertical axis vibrations. The approach to multifrequency vibration includes a separate consideration of the discomfort associated with each frequency component or band of the total spectrum, and a subsequent empirical weighting of the discomfort components of these frequency bands when in various random combinations. Mathematically, this may be represented as: [Formula: see text] The discomfort (DISC) represents the subjective discomfort associated with the acceleration level of a particular frequency band. The F value, or masking factor specifies the fashion in which the discomfort of different frequency bands are added together. Fundamental to this approach is a detailed understanding of human response to discrete frequency inputs. A study has been recently completed that included 186 subjects, exposed to frequencies of 1 to 30 Hz, and ranging in acceleration level from 0.05 to 0.50 peak g. The F value was derived in a second set of tests that systematically explored the passenger discomfort response as a function of various random spectra. The results are in the form of equal discomfort curves that specify the discomfort associated with discrete frequencies between 1 and 30 Hz, of varying acceleration levels. These results, in addition to being necessary for the above equation, provide detailed information of the human discomfort response to increases of acceleration level, for each frequency investigated. More importantly, the results provide a method for adding the discomfort associated with separate frequencies for a total typification of the discomfort of a random spectrum of vibration.
Systematic Selection of Shift Plans for Continuous Production with the Aid of Work-Physiological Criteria
Authors: Knauth Peter , Rohmert Walter , Rutenfranz Joseph 
Published: January 2012

Taking into account the numerous theoretically possible shift systems, we chose sensible shift systems with the aid of objective work-physiological criteria, e.g. the duration of the daily working time, the positioning and duration of sleep and recreation time. With an agreed 40-hour-week shift systems with a weekly working time of 42 hours are more advantageous. If the shifts are equally attended over 24 hours the following shift systems are recommended: when you have 8-hour-shifts the relation between the number of working days and the number of free days should be “3 n/n”, whereby n must be larger than 1, within one shift rota. In the exceptional case of a twelve-hour-shift the corresponding relation should be “2n/2n”. Furthermore unsuitable and recommendable shift plan examples are demonstrated for these shift systems.
Cooling with Box Fans
Authors: Rosen Eric , Konz Stephan 
Published: January 2012

Two experiments are described. Experiment 1 investigated the preferred direction of air upon a person. Forty males sat in front of a box fan in 12 different seating orientations (30° increments). Air velocity was .7 m/s (140 ft/min); room temperature was 28 C (82 F) with 40% rh. The preference was bimodal with the most preferred directions from the front or the rear; velocities from the side were less preferred. Experiment 2 investigated 3 velocities (“still air”, .8 m/s (160 ft/min) and 1.3 m/s (260 ft/min)) at 3 temperatures (25.6, 27.8 and 30 C; 78, 82, 86 F). Eight subjects each spent three hours in each of the 9 conditions. Clothing was standardized at about .5 clo. Subjects did a paper and pencil task (maze) and a peg into hole task. Thermal comfort and thermal sensation ballots were completed every 15 min. At the end of 150 min., they moved their chair in relation to the fan so as to select their preferred velocity. The current recommended ceiling of .8 m/s for sedentary office work is too low as the subject-selected velocity was .7 m/s at 25.6 C, was 1.0 m/s at 27.8 C and was 1.2 m/s at 30 C. These results were confirmed by the thermal comfort and thermal sensation ballots. Depending on the criterion used, for seated sedentary work in warm conditions, every 0.1 m/s (20 ft/min) increase in air velocity offsets approximately a 0.4 C (0.7 F) increase in temperature (0.7 < V < 1.2 m/s).
Synthesized Voice Warning Messages: Effects of Alerting Cues and Message Environment
Authors: Hakkinen Markku T. , Williges Beverly H. 
Published: January 2012

The use of Voice Synthesis Technology (VST) in human/computer dialogues has not received much attention in the human factors literature. Therefore, guidelines for implementing VST systems must be based upon data from natural speech situations published in human factors handbooks. One of the more promising environments for VST is a high workload situation in which the user's visual sensory channel may be heavily burdened with information related to the primary task while a lesser amount of information is present in the auditory channel. The use of VST allows information presented visually to be shifted to the less loaded auditory channel. VST can also serve as a redundant source of information to increase the probability of correct message reception by the user. Characteristics of auditory signals, such as serving an alerting function, make them well-suited for the presentation of urgent and time-critical messages. Although human factors design handbooks suggest that voice messages should be preceded in time by an alerting tone (e.g., Woodson, 1981), recent research (Simpson and Williams, 1980) refutes this design guideline. The present study examined the effectiveness of cueing signals for auditory warning messages as a function of the amount of information presented by voice synthesis and workload in a task that primarily involved visual information. At issue here is whether or not information is lost because of the need to transition attention from one sensory channel to another. Subjects performed a task similar to that found in a simplified air traffic control environment. Users were required to monitor two visual displays and to enter commands via a standard keyboard. Workload was varied by changing the number of aircraft the subject had to control simultaneously. Emergency messages were always presented by synthesized speech. However, the presence of an alerting cue (light and tone) prior to the emergency messages and the presentation mode (visual or auditory) of non-critical messages were varied experimentally. When non-critical messages were presented by synthesized speech, subjects were required to monitor only one display. Subject response times to detect and respond to emergency messages and system-generated information requests, accuracy of message transcriptions, aircraft control performance, and subjective ratings of the presentation modes were analyzed. Recommendations for human factors engineers involved in the design of systems using VST will be presented.
Toward Speaker Independent Voice Recognition
Authors: Poock Gary K. , Schwalm Norman D. , Roland Ellen F. 
Published: January 2012

The purpose of this study was to investigate the extent to which off-the-shelf voice recognition equipment can perform as a speaker-independent system. By “speaker independence” is meant the ability of the system to be used by a larger number of individuals than that which trained the system (but including those who trained it), and by individuals different from those who trained it. Several independent groups of five subjects trained a threshold T600 voice recognition unit, each subject training the same 50 utterances for a total of 250 utterances. Later, a number of testing trials were conducted wherein subjects tested the system using 1) the 50 utterances that they trained, 2) the utterances that they trained plus the utterances trained by the other four subjects, and 3) the utterances trained only by the other four subjects. Measures of recognition accuracy were percent nonrecognitions and percent misrecognitions. Results will be discussed in light of additional applications for voice recognition if currently available systems prove to be able to function well in a speaker independent mode.
Human Factors, Organizational Design, and Productivity: Alternative Management Systems
Authors: Brown Ogden 
Published: January 2012

The American labor force is presently undergoing an evolutionary change which contains certain implications with respect to the ways in which organizations are designed and managed. The principal trends which have emerged are: the changing composition of the labor force, changing attitudes and values of the individual worker, and the emergence of alternative management systems (herein termed quality of work life programs) as a response to cope with this evolution. Many of these programs are concerned with varying the structure and design of the organization, redesign of the work environment, and the adoption of alternative management styles and methods. In an era of slower growth, declining productivity, and stiffer world wide competition, the solution to “people problems” is now just as consequential as is the introduction of new technologies and the generation of capital. Evidence is rapidly mounting that quality of work life programs do appear to be of help in achieving the desirable goals of improved quality and productivity, and increased job satisfaction on the part of the worker. Such programs are not, of course, unique to American organizations. This symposium includes a discussion of programs employed in West Germany and in Japan as well as in the United States. American programs presented include those of the subsidiary of a Japanese firm, and those of two large, highly successful organizations with outstanding records of employee relations and quality of work life programs. Time will be available for audience interaction and questions.
Training Device Fidelity and Transfer of a Perceptual Motor Skill
Authors: Baum David R. , Riedel Sharon L. , Hays Robert T. 
Published: January 2012

The objective of this study was to determine the relationship between training device fidelity and transfer of training for a perceptual-motor maintenance task. The task was truing a bicycle wheel. Fidelity was operationally defined in terms of the physical and functional similarity (PS and FS, respectively) of each device to the actual equipment. Five experimental conditions were employed, each using one of the following devices: 1. Actual equipment (High PS/High FS) 2. Facsimile equipment (Medium PS/Medium FS) 3. Line drawings (Low PS/Low FS) 4. Inoperative actual equipment (High PS/Low FS) 5. Computer graphics model (Low PS/High FS) One hundred non-college bound high school students served as subjects, with 20 randomly assigned to each condition. The training method consisted of the following: (1) A demonstration of the task on the device appropriate to the experimental condition; (2) practice on the device (subjects in Condition 1 had one 15-minute practice trial); and (3) two 15-minute performance trials on the actual equipment. For example, in Condition 3 the subjects were first shown pictures of the various equipment components and the process of truing the wheel was explained; this was followed by problems in which the subjects had to state what they would do to correct the depicted deviation and point out how they would do it. Feedback was provided in all conditions. Performance accuracy in terms of millimeters of lateral rim deviation was measured automatically at 3-minute intervals during trials of 15-minutes duration. The results indicate that there is no effect of overall fidelity on task performance. However, the results show that physical similarity is a significantly more important determinant of skill acquisition for this task than functional similarity. The results support the idea that training device fidelity can be usefully defined along at least two dimensions; and it can be systematically varied and its effects on learning studied. The results have implications for the kind of guidance to provide to training program managers who must make cost-effective decisions regarding device features. Future research will investigate the potentially interactive effects of variables like task complexity and subject aptitude.
A Data Bank for Human Related Events in Nuclear Power Plants
Authors: Metwally A. Mohsen M. , Sabri Zeinab A. , Adams S. Keith , Husseiny Abdo A. 
Published: January 2012

The authors introduce a comprehensive survey and evaluation of presently available data sources in nuclear power plants. A newly developed classification format for human related events is proposed. The format presents all necessary information in a coded form to support human reliability analysis and the assessment of performance shaping factors. Recommendations are given for improving data sources to facilitate the evaluation of man-machine interfaces and human performance in nuclear power plants.
Incidence and Patterns of Product Related Accidents among the Elderly
Authors: Czaja Sara J. , Hammond Katka , Drury Colin G. 
Published: January 2012

Accidental deaths and injuries involving consumer products and environments represent a major health hazard and cost to the nation. Among persons of all ages, accidents are the leading cause of death. Previous research into the causes of accidents has generally not been age specific but the present study, recognizing that the elderly incur a high rate of accidental injuries and fatalities (a death rate more than twice that of the population at large), has selected and analyzed the available empirical data to substantiate the seriousness of product-related accidents for people over age 55. The data sources used in this study were provided by the U.S. Consumer Product Safety Commission (CPSC). They included: computerized data on the number and severity of injuries (the National Electronic Surveillance System or NEISS); narrative detailed descriptions of accidents with selected products (the In-Depth Investigations or IDIs); and computerized death certificate data. Criteria for selection were developed and the 49 most hazardous products for people over 55 were identified using the NEISS data and ranked. Using five-year increments for age 55 and up, hazardous products were ranked again. Floors and flooring materials, for example, appeared as one of the two most hazardous product categories, both for all elderly people as well as individual five-year spans. The 49 products were then ranked by accident cost (developed from CPSC's Injury Cost Model). Again, from a national estimate for emergency room treated injuries, floors and flooring materials rank second in cost after stairs and steps followed by foods, lawn mowers, ladders, bathtubs and showers among other products. In order to understand the accidents' etiology, hazard patterns have been constructed, describing major patterns of accidents common to the elderly. In addition, for the highest priority cost or highest priority accidents, a more detailed human factors analysis has been performed in order to describe the causes of these accidents.
Vibroacoustic Habitability of Space Stations
Authors: Stephens David G. , Willshire Kelli F. , Chambers Randall M. , McCauley Michael E. , Guignard John C. , Pearsons Karl S. , Johnson Daniel L. 
Published: January 2012

To insure efficient utilization of the system, space station design and operations will require special habitability considerations for the occupants and crew because of the relatively long duration missions. Of particular concern is the environment in which the personnel will live and work, and how it affects both the performance and comfort of the occupants. The vibroacoustic aspect of that environment is the subject of this forum session. Although noise and vibration exposure criteria have been developed for earth-based work and living situations, several factors make the application of these criteria questionable in the context of space station design and operation. The interior noise and vibration environment of a space station is different in level and frequency than a comparable earth-based system. Complicating factors associated with reduced gravity, long duration and confinement are not included in existing criteria. In applying the criteria to space system designs, these factors either have been neglected or considered unimportant. The need for improved habitability is evidenced by physical and subjective assessments of previous missions. Astronauts have reported sleep interference, communication interference, distraction, and general annoyance as noise related complaints. The goal of the discussion is to establish, as Human Factors Specialists, where we are; what we should consider; and what the problems are as well as possible approaches and solutions. In other words, the aim is to stimulate thinking about space station vibroacoustic habitability that could ultimately lead to new research and technology in this area. Effects of the vibroacoustic environment on performance, hearing, communication, sleep, health, and annoyance will be discussed, as well as the results of interactions between the vibroacoustic environment and duration, weightlessness, and confinement.