bluuebunny/crossref_metadata_2025 huggingface dataset:
Use of the Putamen as a Surrogate Anatomical Marker for the Internal Segment of the Globus Pallidus in Deep Brain Stimulation Surgery
Authors: Thompson John A. , Yin Dali , Ojemann Steven G. , Abosch Aviva
Published: July 2017

Objective: The success of deep brain stimulation (DBS) of the internal segment of the globus pallidus (GPi) depends on accurately placing the electrode into the GPi motor territory. Direct targeting can be difficult as GPi laminar borders are not always clearly identifiable on MRI. Here, we report a method for using the putamen (PUT) as a surrogate anatomical marker to target the GPi. Methods: We developed a PUT-based GPi targeting using the FGATIR (fast gray matter acquisition T1-weighted inversion recovery) MRI sequence and compared it with consensus coordinate-based indirect targeting. Stereotactic target coordinates were obtained and analyzed. Results: In our GPi DBS case sequences, GPi borders were unresolvable on T2-weighted MRI. However, in all cases, application of the PUT-based method resulted in consistently localized GPi targets, which were confirmed by merging the T2-weighted MRI with the FGATIR MRI. Significant differences were noted in the target coordinates between the PUT-based method and indirect targeting based on both the distance from the anterior commissure and the distance from the intercommissural plane. The mean differences for mediolateral distance and anteroposterior distance were 1.4 and 1.42 mm, respectively. In addition, the PUT-based method estimated a target that was closer to the nearest implanted electrode. Conclusion: Our PUT-based method allows consistent and precise patient-specific GPi targeting. Further study is planned to correlate PUT-based GPi targeting with microelectrode recording, location of active contact of the DBS electrode and clinical outcome.
Quality of Life and Caregivers' Burden of Parkinson's Disease
Authors: Rajiah Kingston , Maharajan Mari Kannan , Yeen Si Jen , Lew Sara
Published: July 2017

Aim: This study focused on the impact of the clinical features on the quality of life (QoL) of Parkinson's disease (PD) patients and of their caregivers. Methods: This study included PD patients along with their caregivers and was undertaken at the Malaysian Parkinson's Disease Association from June 2016 to November 2016. Clinical features of PD patients were assessed using the Movement Disorder Society revised Unified Parkinson Disease Rating Scale; the Hoehn and Yahr stage and the Schwab and England Activities of Daily Living Scale were used to assess the severity and the ability of PD patients respectively. QoL of PD patients was measured using the Parkinson's Disease Questionnaire-39 (PDQ-39). The revised version of the Zarit Burden Interview assessed caregiver burden. Results: At least one of the clinical features affected PD patients' QoL, and at least one of the QoL domains affected the caregivers' burden. Clinical features “saliva and drooling” and “dyskinesia” explained 29% of variance in QoL of PD patients. The QoL domains “stigma,” along with “emotional well-being” explained 48.6% of variance in caregivers' burden. Conclusions: The clinical features “saliva and drooling” and “dyskinesia” impacted the QoL of PD patients, and the QoL domains “stigma” and “emotional well-being” of PD patients impacted their caregivers' burden.
Taxonomic clarification of the Eumicrotremus asperrimus species complex (Teleostei: Cyclopteridae) in the eastern North Pacific
Authors: STEVENSON DUANE E. , MECKLENBURG CATHERINE W. , KAI YOSHIAKI
Published: July 2017

The Eumicrotremus asperrimus species complex includes three nominal species from the eastern North Pacific and Bering Sea: Eumicrotremus gyrinops (Garman 1892); Eumicrotremus muticus (Gilbert 1896); and Eumicrotremus phrynoides Gilbert & Burke 1912. These species have been distinguished from each other primarily on the basis of the strength and coverage of bony tubercles on the head and body. However, several recent genetic studies have cast doubt on the utility of bony tubercles for diagnosing species-level differences among cyclopterids, and a recent genetic study of the E. asperrimus species complex indicated that population structure is not correlated with tubercle development. Here we present additional evidence from the mitochondrial COI gene indicating that there is little genetic structure within a sample of specimens from the eastern North Pacific and Bering Sea with a wide range of tubercle development. We also examine several lines of morphological evidence, including meristic and morphometric data and osteology, and conclude that the three nominal species described from the eastern North Pacific represent a single polymorphic species. We present a redescription of Eumicrotremus gyrinops (Garman), the oldest of the three nominal species, recognizing the other two nominal species of the Eumicrotremus asperrimus species complex described from the eastern North Pacific as junior synonyms. Individuals of this highly polymorphic species may be covered in large bony tubercles, or sparsely covered in small tubercles, or may have no evidence of tubercles at all. There is clear evidence of sexual dimorphism, as males tend to have fewer and smaller tubercles than females, and all large specimens (> 58 mm SL) are females. Both males and smaller females may lack any evidence of tubercles.
Redescription of Micaria beaufortia (Araneae, Gnaphosidae), with notes on Afrotropical Micaria
Authors: MARUSIK YURI M. , OMELKO MIKHAIL M.
Published: July 2017

Three species of Micaria Westring, 1851 are known to occur in the Afrotropical Region, two from Namibia and one from South Africa. All three species are known from a single sex only, either from the male (M. tersissima Simon, 1910) or from the females in the case of M. beaufortia (Tucker, 1923) and M. chrysis (Simon, 1910). In this paper, we redescribe the female of M. beaufortia and describe the previously unknown male of this species. This species has pseudosegmented tarsi and complex scopula formed by two paired rows of setae; these characters are unknown in other Micaria. The setae covering the legs in M. beaufortia are briefly described and the scopula is compared with that of M. fulgens (Walckenaer, 1802). A paired mating plug, previously unknown in Micaria, is documented in M. beaufortia. It was found that M. chrysis and M. tersissima, considered in the World Spider Catalog (2017) as endemics of Namibia, were actually described from Northern Cape Province, South Africa. The taxonomic position of these two species is briefly commented on and distribution records of all three species are mapped.
Plagiostenopterina sagarensis sp. nov. (Diptera: Platystomatidae: Platystomatinae) from Sunderban Biosphere Reserve, India with a key to Indian species
Authors: ROY SANKARSAN , PARUI PANCHANAN , MITRA BULGANIN
Published: July 2017

Plagiostenopterina sagarensis sp. nov., a new platystomatid species, from Sunderban biosphere reserve, India, is described with illustrations. A key to Indian species of genus Plagiostenopterina Hendel is also provided. The holotype and paratype specimens of the new species are deposited in the National Zoological Collections of Zoological Survey of India, Kolkata.
Rediscovery of Chinommatia littoralis (Tesch, 1918) (Crustacea: Decapoda: Brachyura: Chasmocarcinidae) from Tanimbar Island, Indonesia
Authors: NG PETER K. L. , RAHAYU DWI LISTYO
Published: July 2017

The male of Chinommatia littoralis (Tesch, 1918) is described for the first time based on material from Tanimbar Island, Indonesia. The structure of the male first and second gonopods are distinct and more closely resemble those of Notopelta mortenseni (Serène, 1964), but the species is retained in Chinommatia Ng & Castro, 2016, because of the structure of its carapace, cheliped, and thoracic sternum. Specimens reported as C. littoralis from Vietnam by Zarenkov (1972) and South China Sea by Chen (1998) are in fact C. cavimanus (Rathbun 1914). Zarenkov’s (1972) record of Chinommatia cavimanus from Vietnam belongs to Chasmocarcinops gelasimoides Alcock, 1900, instead.
Predictors of Physical and Dating Violence in Middle and High School Students in the United States
Authors: Higgins George E. , Marcum Catherine D. , Nicholson Jason , Weiner Phillip
Published: July 2017

Dating violence is a growing and prominent problem for today’s middle and high school students. Intimate partner violence, which can include physical, sexual, emotional, and psychological aggression, affects millions of individuals worldwide. This specific study will examine one age group affected by this rampant phenomenon: adolescents under the age of 18. The purpose of this study is to continue the examination of correlates of dating violence, specifically physical and sexual, through the analysis of data from the 2015 Youth Risk Behavior Survey and application of Routine Activities Theory. Results support hypotheses that the components of Routine Activities Theory are moderate to strong predictors of physical and sexual dating violence in adolescents.
An impact evaluation of the FoodMate programme: Perspectives of homeless young people and staff
Authors: Meiklejohn Sarah J , Barbour Liza , Palermo Claire E
Published: July 2017

Objectives:

Food insecurity remains an issue for vulnerable populations in developed countries. The potential dietary and food security impacts of nutrition education programmes in Australia remain largely undocumented. This study investigated the impacts of an eight-session nutrition education programme delivered within community case management services for young people experiencing homelessness.

Design and setting:

A qualitative case study was undertaken in a community-based youth housing agency in Western Melbourne, Australia.

Methods:

Seven semi-structured interviews and two focus groups were conducted with a purposive sample of 10 past programme graduates and five youth service staff. Data were thematically analysed using a phenomenological lens.

Results:

The impacts of the programme were described by four themes: (1) the nutrition education programme created a platform for social engagement, (2) reduced reliance on emergency food relief for participants, (3) participants developed food-related knowledge and skills and (4) the programme was seen as a step towards food security for young people. These impacts were dependent on a myriad of personal and programme-related characteristics. Personal characteristics included participants’ intrinsic motivating factors to change their behaviours or a pre-existing interest in nutrition. Programme characteristics included the programme’s flexible structure and facilitation by caseworkers that were known to the young people.

Conclusion:

Study findings highlight the potential impacts of a nutrition education programme on dietary behaviours and food security status when embedded within community-based services.
Review, Evaluation, and Comparison of Models for Predicting Lifting Capacity
Authors: Ayoub M. M. , Mital Anil , Asfour Shihab S. , Bethea N. J.
Published: July 2017

Models related to lifting activities have been classified and reviewed. Predictive models are grouped under psychophysical capacity modeling, physiological energy requirement modeling, and biomechanical stress modeling. Within each group, the models have been compared and evaluated. In addition, psychophysical and physiological model groups have been compared.
Development of Strength and Capacity Norms for Manual Materials Handling Activities: The State of the Art
Authors: Ayoub M. M. , Ayoub M. M. , Mital Anil , Bakken Gary M. , Asfour Shihab S. , Bethea N. J.
Published: July 2017

Literature related to manual materials handling activities is reviewed and recommendations are made for the maximum acceptable weight of lift for male and female workers, based on the psychophysical approach.
A Design Tool for Estimating Passenger Ride Discomfort Within Complex Ride Environments
Authors: Leatherwood Jack D. , Dempsey Thomas K. , Clevenson Sherman A.
Published: July 2017

A series of experimental studies utilizing approximately 2200 test subjects has led to the development of a general empirical model for the prediction of passenger ride discomfort in the presence of complex noise and vibration inputs. The ranges of vibration and noise stimuli used to derive the model included the amplitudes and frequencies that are known to most influence passenger comfort. The ride quality model accounts for the effects of combined axis vibrations (up to three axes simultaneously) and includes corrections for the effect of vibration duration and interior noise. Output of the model consists of an estimate of the passenger discomfort produced by a given noise and/or vibration environment. The discomfort estimate is measured along a continuous scale that spans the range from below discomfort threshold to values of discomfort that are far above discomfort threshold.
An Information-Processing Interpretation of Air Traffic Control Stress
Authors: Finkelman Jay M. , Kirschner Carl
Published: July 2017

The air traffic controller's job is inherently stressful, resulting in a variety of stress-related symptoms and illnesses. Unusually high information-processing demands are placed upon controllers for extended periods of time, so that they often must work close to the limits of their channel capacity. The effort required to process information, maintain continuous concentration, and render timely and reasonable decisions is likely to be very stressful. Although stress-related performance decrements would not be acceptable in the typical air traffic control situation, the effects of stress may manifest themselves in social and family relationships and in physical and mental health. It is possible that laboratory measures of information processing (such as the delayed digit recall subsidiary task) could be used to evaluate reserve capacity and thereby predict the ability to cope with stress. Air traffic controllers with higher channel capacities may be less likely to make errors under conditions of stress and less likely to suffer the physiological consequences associated with high information-processing demands.
Cockpit Displayed Traffic Information and Distributed Management in Air Traffic Control
Authors: Kreifeldt John G.
Published: July 2017

The technical feasibility of graphically displaying information such as surrounding aircraft and navigation routes in the cockpit on a cathode ray tube has been suggested as a viable method for improving the safety, orderliness, and expeditiousness of the air traffic control system by distributing some of its management to the pilots equipped with this cockpit displayed traffic and navigation information (CDTI). Several years of experimental study of this Concept, using a three-cab simulator facility at NASA-Ames, have produced several consistent findings relating to system performance and pilot and controller work loads and opinions. These findings generally agree with those from other studies.

The most consistent result is a considerable reduction in controller verbal work load without any appreciable increase in pilot verbal work load, although they may report an increase in visual work load. However, pilots tend to prefer distributed management to centralized management, while this is generally reversed for controllers. The reduced response delays in the system obtainable using CDT/ permit pilots to maintain their own spacing more closely and precisely than when depending entirely upon controller-issued radar vectors and speed commands. As a result, time between successive aircraft landings and its variability can be reduced, thereby increasing runway utilization. Limited findings suggest that CDTI-based benefits do not detract from system safety.

On balance, distributed management offers significant advantages for air traffic control.
Person-Environment Relationships in Adulthood: Implications for Human Factors Engineering
Authors: Fozardi James L.
Published: July 2017

Environments for aging and the aged are best designed if human factors engineers incorporate a developmental view of adulthood in their planning. Accordingly, environments for living should be designed to accommodate the transitions between stages of adult life as well as the periods of stability. The optimal human factors interventions involve both psychosocial and physical aspects of the environment and include changing people through psychological intervention. Examples of human factors engineering for aging in perception, learning, and memory, as well as work, leisure, and health, illustrate areas that require successively more complicated plans for intervention.
The Anthropometry of the Elderly
Authors: Stoudt Howard W.
Published: July 2017

The anthropometric elderly, arbitrarily defined as those 65 years of age and above, are a distinct subgroup with special human factors needs. They are significantly smaller in stature and in many other body dimensions than the general population. This smaller size results both from the secular trend (people are currently growing taller and larger than in the past) and from various biological changes inherent in the aging process. Weight and certain other dimensions are less age-affected, however, except at more advanced ages. Existing information on the anthropometry of the elderly is reviewed, and tabular data are presented on selected “human engineering” dimensions. Additional, more comprehensive, functional anthropometric data are needed for this population.
A Methodology for Quantifying the Effects of Aging on Perceptual-Motor Capability
Authors: Levison William H.
Published: July 2017

A methodology is described for providing a quantitative description of the effects of aging on human perceptual-motor capability. Specifically, application of the experimental and analytical techniques of manual control is suggested so that these effects can be quantified in terms of the parameters of a model for human perception and control.

Important and immediate contributions to the study of aging can be expected from application of the methodology outlined in this paper. First, measures of perceptual-motor performance that are expected to be more sensitive to the effects of age than those usually available will be obtained. Second, these measures will be interpretable in terms of a model for human information processing that has been validated extensively for subjects in the 20-to 40-year age bracket. Using this model, one would be able to predict the effects of aging on a variety of tasks. Finally, a basis would be developed for a functional (rather than chronological) description of aging.
Monitoring for One Kind of Signal in the Presence of Another: The Effects of Signal Mix on Detectability
Authors: Craig Angus
Published: July 2017

Subjects in a 1-h visual vigilance task looked for the occasional presence of a signal inserted into a sequence of single items which consisted of either (a) homogeneous nonsignals or (b) a mixture of nonsignals and signals of another kind. The experiment also manipulated the nature (and discriminability) of the signal to be detected (two types) and its probability of Occurrence (0.05 or 0.15). Results indicate that signal detectability is impaired by the presence of another kind of signal, the impairment tending to be greater the lower the detectability of the signal considered on its own. But, due to a concomitant increase in response bias, the impairment is not reflected in correct detection. The presence of the second signal did not influence the extent of the within-session decline in detection, and the effect of signal probability on detection levels failed to emerge. The practical implications of the findings are discussed.
Data Entry Performance as a Function of Method and Instructional Strategy
Authors: Gade Paul A. , Fields Alison F. , Maisano Richard E. , Marshall Charles F. , Alderman Irving N.
Published: July 2017

In Experiment 1, a response-sensitive instructional strategy was compared to three traditional, linear, instructional strategies for use in an embedded training program designed for manual data entry operators in the Army Tactical Operations System command and control system. Results showed that using a response-sensitive strategy can reduce training time without reducing inputting accuracy in a post-training test given in an operational setting. Experiment 2 examined the relative efficiency of [our different manual data entry methods: typing; typing with an error corrector; selecting from menus; and typing with autocompletion and an English option. Results show that selecting from menus is the most accurate inputting method. No differences were found in entry times among the methods, although participants may not have had sufficient practice for such differences to materialize. Results also showed little agreement between preference and performance for the methods.
An Evaluation of Alphanumeric, Graphic, and Color Information Displays
Authors: Tullis Thomas S.
Published: July 2017

Four different types of CRT display formats were evaluated in the context of a computer-based telephone line testing system. The formats considered were narrative, which used complete words and phrases; structured, which used a tabular format; black-and-white graphics, which used a schematic of the telephone line; and color graphics, which also used a schematic but added color coding. The evaluation measured speed and accuracy of the subjects' interpretation of the displays of test results. Accuracy did not significantly vary with format but speed did. Response times for both graphic formats were consistently shorter than those for the narrative format. With additional practice, however, response times for the structured format were just as short. There was no significant difference between response times for the black-and-white graphic and color graphic formats.
Alcohol, Task Difficulty, and Incentives in Drill Press Operation
Authors: Price Dennis L. , Flax Robert A.
Published: July 2017

Virginia Polytechnic Institute and State University, Blacksburg, Virginia Four levels of blood alcohol concentration (BAC), eight levels of task difficulty, and two incentive conditions were examined for their effect on hits and misses in a simulated drill press operation. Hits were defined as inserting the drill probe within a hole in a plate without touching the probe to the plate. Misses were defined as drill probe strokes in which the drill probe touched the plate. Task difficulty was defined by an adaptation of Fitts' Law. Incentive conditions for speed or accuracy were maintained using monetary reward. The BAC levels used were placebo, 0.03%, 0.06%, and 0.09%. There was a significant (p = 0.0001) effect of alcohol on hits, with a decrement of 12% and 19% at the 0.06% and 0.09% levels. Incentive conditions had a significant effect on both hits (p = 0.0002) and misses (p = 0.0001). Task difficulty also had significant effects on hits and misses (p = 0.0001). There was no evidence of meaningful interactions among these main effects, although some interactions were statistically significant.
Effects of Video Display Terminals on Telephone Operators
Authors: Starr Steven J. , Thompson Claudia R. , Shute Steven J.
Published: July 2017

A self-administered questionnaire was completed by 145 Directory Assistance operators who used video display terminals (VDTs) to retrieve listings and by 105 control subjects who performed identical work except that they retrieved listings from printed paper records. The two groups exhibited few differences in their experience of work-related physical discomfort, in job satisfaction, or in their concerns about job security. Both groups were found to use eyeglasses and contact lenses to the same extent. VDT operators generally did not obtain special corrective lenses for work. The results show that replacing paper documents with VDTs need not adversely affect the comfort and morale of office workers.
Using Retroreflective Material to Enhance the Conspicuity of Coal Miners
Authors: Beith Barry H. , Sanders Mark S. , Peay James M.
Published: July 2017

This study investigated the use of retroreflective material to increase conspicuity of miners. A scaled simulation was created using dolls configured as miners. Twelve observers viewed four configurations of retroreflective material on dolls in three body postures at one of three locations in the visual field. In a subsequent experiment, nine observers compared two configurations. The results confirmed the poor conspicuity of the configuration currently required in mines, which features retroreflective tape on the helmet only. All experimental retroreflective configurations significantly improved detectability over this configuration. Overall, the most cost-effective configurations were those in which the belt and/or armbands were covered with retroreflective material.
VDT Workstation Design: Preferred Settings and Their Effects
Authors: Grandjean E , Hünting W. , Pidermann M.
Published: July 2017

A field study was conducted to assess the preferences of VDT operators with regard to their body posture and the settings of an adjustable VDT workstation. Subjects came from four different companies, and the study took place during subjects' customary working activities. Means and ranges of the preferred settings are given. The operators preferred body postures that are distinctly different from those recommended in textbooks and other publications. Some of the workstation settings they preferred also strongly deviate from such recommendations.
Compatibility and Resource Competition between Modalities of Input, Central Processing, and Output
Authors: Wickens Christopher D. , Sandry Diane L. , Vidulich Michael
Published: July 2017

Synthesized auditory displays and speech recognizers were used in two experiments to develop guidelines for their implementation in military aircraft. In the first experiment, the competition between encoding and response modalities of concurrent tasks was examined. The memory search task was more susceptible to competition for visual encoding, whereas the tracking task bore the greater impact from shared manual responding. The second experiment examined competition between tasks for encoding and response modalities and the optimum assignment of modalities to a given task. A simulated flight task was performed concurrently with either a spatial task (target acquisition) or a verbal task (memory). Best performance and least interference with the flight task were obtained when the spatial task was displayed visually and responded to manually and also when the verbal task was displayed auditorily and responded to with speech.
Acceleration Exposures in Forward Seating Areas of Bowrider Recreational Boats
Authors: Wiker Steven F. , Miller James M.
Published: July 2017

The objective of this study was to measure acceleration levels to which passengers would be subjected in the fonvard seating areas of two styles of bowrider recreational boats. Acceleration exposure data were collected aboard a monohull and a trihull boat as they crossed 0.48- and 0.76-m wakes at speeds of 24 and 40 km/h. Substantial increases in maximum peak accelerations and their rates of onset were found with increases in boat speed and wake height. Vertical acceleration levels and their onset rates were lowest aboard the monohull; however, the effects of boat speed and wake height upon vertical acceleration exposures were much greater than differences found between boats. Similar findings were obtained for longitudinal acceleration measures. Based upon presently available human acceleration tolerance information, the risk of spinal compression fracture aboard the boats examined appears remote due to the very short durations of the accelerations endured.
Human Factors in Consumer Product Accident Investigation
Authors: Drury Colin G. , Brill Michael
Published: July 2017

Using task analysis as a basis, a job aid was developed to enable accident investigators to obtain human factors data during their investigations. For each product, a limited number of characteristic accident patterns were found; these are referred to as hazard patterns or scenarios. These patterns were used to structure "intelligent" questionnaires, with sections on the victim, the task, the product, and the environment.
Design Strategies for Computer-Based Information Displays in Real-Time Control Systems
Authors: Mitchell Christine M. , Miller R. A.
Published: July 2017

Two strategies are defined for the design of integrated, computer-based information displays for real-time control systems. Subjects controlled a simulated system using a conventional display console or one of two integrated displays. The effects of display type on operator performance were considered. Integrated displays tended to degrade performance unless the display preprocessed information, synthesizing and presenting it in a form more compatible with an operator's high-level information needs.
Biomechanical Stresses as Related to Motion Trajectory of Lifting
Authors: Garg Arun , Sharma Deven , Chaffin Don B. , Schmidler John M.
Published: July 2017

A laboratory study was conducted to assess the effects of lift angle on biomechanical stresses to the musculoskeletal system, and in particular, on the lower back. Male subjects were required to lift four different tote boxes from the floor to a height of 0.81 m using two different lifting techniques. Maximum acceptable weights were determined using a psychophysical method. The motion trajectory of lift was studied by means of stroboscopic photography. Moments and forces at various body joints were computed using a biomechanical strength model.

Maximum acceptable weights were 16% (range = 9 to 23%) greater for the free-style lifting technique as compared with the squat method of lifting. There were large differences between the maximum acceptable weights and the "maximum permissible limits" recommended by NIOSH. The results showed that the subjects pulled the load toward the body when lifting psychophysically determined maximum weights. The lift angle increased with an increase in box width. The lift angle was greater for the free-style lifting method as compared with the squat lifting technique for lifting compact loads. Lifting at an angle resulted in a decrease in moment at the elbow, shoulder, L5IS1 disc, and hips, and an increase in moment at the knees and ankles. The estimated compressive force on the lumbar spine was, on the average, 11% lower for lifting at an angle as compared with a straight vertical lift.
Perception of Simulated Propeller Cavitation
Authors: Howard James H. , Ballas James A.
Published: July 2017

A stochastic model is proposed to describe the perceptual processes that underlie the classification of complex multidimensional sounds, such as passive sonar signatures. The model is based on four assumptions: (1) complex sounds may be represented psychologically as points in a multidimensional perceptual space, (2) categories are represented theoretically as distributions in this space centered at ideal category members or prototype, (3) the category distributions determine the conditional stimulus probabilities and have multivariate Gaussian form, and (4) individual dimensions in the perceptual space may be weighted differentially to reflect a listener's attentional processes. To evaluate the model, two groups were tested in an eight-category classification task involving 16 simulated propeller cavitation sounds. A perceptual structure was determined for the sounds in a preliminary non-metric multidimensional scaling study. The two groups received category assignments that stressed different properties of the cavitation sounds. An observed confusion matrix was derived by fitting the model to the observed data. Overall, comparison of the obtained and theoretical data indicated that the model provides a reasonable description of how listeners classify complex simulated sonar sounds. The assumption that listeners can selectively and independently adjust the relative importance of the perceptual dimensions was also supported. The utility of the proposed model as a tool for the development of preprocessing aids and training programs for sonar operators is discussed.
The Formatting of Alphanumeric Displays: A Review and Analysis
Authors: Tullis Thomas S.
Published: July 2017

This paper surveys the literature on alphanumeric display formatting, focusing primarily on computer-generated displays. Two general areas are included: guidelines addressing display design and empirical studies of displays. Four characteristics of display formats are described: overall density, local density, grouping, and layout complexity. Objective measurement techniques for these characteristics are proposed and are applied to two different display formats. The results suggest that these measures could provide the basis for objectively evaluating a display without collecting performance data.
The Tide of Computer Technology
Authors: Williges Robert C.
Published: July 2017

Advances in computer technology mark the beginning of an information revolution that will provide new challenges for human factors. New application areas that need to be considered include education, the working environment, and consumer services. Professional implications of computer technology for the Human Factors Society involve technical information exchange, professional training, and public awareness.
Correlates of Ocular and Somatic Symptoms among Video Display Terminal Users
Authors: Smith Alexander B. , Tanaka Shiro , Halperin William , Richards R. D.
Published: July 2017

A cross-sectional survey was conducted among employees of a large newspaper company (1) to define the type of ocular and somatic complaints reported by video display terminal (VDT) users and to identify their relationship to VDT use, (2) to determine the association between symptoms and the participants' adequacy of correction of refractive errors for their jobs, and (3) to assess the prevalence of eye abnormalities, especially cataracts, and their relationship to VDT use. Poor visual clarity of the VDT screen explained the plurality of work-associated symptoms. These associations were independent of the effects of potential confounding variables. The relationships with headaches associated with work and changes in visual function were replicated in a small, independent sample. One qualitative and two quantitative VDT-use variables that suggested lesser skill or experience were associated with headaches. No meaningful relationship was found between adequacy of the participants' refractions, including the wearing of glasses with bi-or multifocal lenses, and the reporting of work-associated symptoms. No significant association was found between VDT use and the prevalence of eye abnormalities, including cataracts.
Information Retrieval Strategies File-Search Environment
Authors: Elkerton Jay , Williges Robert C.
Published: July 2017

The investigation represents an exploration of search strategies in an information-retrieval task. The task environment consisted of five search procedures: scrolling, paging, string search, absolute line movement, and relative line movement. Independent variables included user, task, and editor characteristics. The user variable was previous interactive computing experience (novice or expert). The task variables were file type (data or text), file length (short or long), and target type (embedded, nonembedded, or repeated). The editor variable was window size (1, 7, 13, or 19 lines). The results of the 2 x 2 x 2 x 3 x 4 mixed-factor experiment indicated that subject experience, file length, target type, and window size, as well as an interaction between subject experience and file length, were the salient factors of file search. Large differences in novice and expert search strategies were also discovered. Most importantly, the investigation revealed the need for adaptive interfaces that can alter in response to a user's style.
Synthesized Warning Messages: Effects of an Alerting Cue in Single- and Multiple-Function Voice Synthesis Systems
Authors: Hakkinen Markku T. , Williges Beverly H.
Published: July 2017

The present study examined the effectiveness of preceding synthesized voice warning messages with an alerting cue as a function of the amount of information presented by the voice synthesizer and the workload level in the primary task. Subjects performed a simplified air traffic control task in which they were required to monitor two visual displays and to enter commands via a standard keyboard. Emergency messages were always presented by phoneme-based synthesized speech. However, the presence of an alerting cue (light and tone) prior to emergency messages and the presentation mode of noncritical messages (visual or auditory) were varied experimentally. When synthesized speech was used only for emergency messages, the presence of an alerting cue lengthened the response time to the message. However, when computer-generated speech was used for multiple functions, more emergency messages were detected when an alerting cue was used.
Verbal Response Times to Directional Traffic Signs Embedded in Photographic Street Scenes
Authors: Shoptaugh Carol F. , Whitaker Leslie A.
Published: July 2017

Response times to left and right directional street signs, embedded in photographic street scenes, were measured. Department of Transportation directional signs were photographically inserted on both the left and right side of the road. Both permissive and prohibitive street signs were used. The effect of field dependence, sex, street scene background complexity, and sign type were of interest. The street scene stimuli were presented briefly (180 ms) using a tachistoscope; subjects' verbal response times were measured. Mean response times for men and women did not differ significantly. Field dependence was significantly correlated with response time. Response times increased significantly as the street scene background was made more complex. Prohibitive word signs resulted in the fastest response times.
Principles of S-C-R Compatibility with Spatial and Verbal Tasks: The Role of Display-Control Location and Voice-Interactive Display-Control Interfacing
Authors: Wickens Christopher D. , Vidulich Michael , Sandry-Garza Diane
Published: July 2017

A pilot's tasks may be categorized into those that demand predominantly verbal operations and those that are spatial. We describe two experiments that define two principles of compatibility of interfacing such tasks with displays and controls. The first, based upon hemispheric laterality effects, defines compatibility according 10 the display location and the response hand; the second defines compatibility according to the modality of display (auditory and visual) and response (manual and speech). Verbal tasks are best served by auditory inputs and speech response, whereas spatial tasks are best served by visual-manual channels. In both experiments, these principles of compatibility are confirmed under dual-task conditions. We describe their implications for cockpit design.
Cockpit Management Attitudes
Authors: Helmreich Robert L.
Published: July 2017

Distinctions are drawn between personality traits and attitudes. The stability of the personality and the malleability of attitudes are stressed. These concepts are related to pilot predominance, especially in the areas of crew coordination and cockpit resource management. Airline pilots were administered a Cockpit Management Attitudes questionnaire; empirical data from that survey are reported and implications of the data for training in crew coordination are discussed.
Posture, Postural Discomfort, and Performance
Authors: Bhatnager V. , Drury C. G. , Schiro S. G.
Published: July 2017

In order to justify the costs of using ergonomically designed workplaces, it is necessary to relate improved posture to improved performance. This experiment used twelve subjects, four in each of three postural conditions. Subjects inspected printed circuit boards for 3 h with two five-minute breaks per hour. Both postural condition and time on task affected measures of posture, measures of postural discomfort, and performance. Poor defect detection performance was associated with increased forward inclination of the trunk, increased perceived discomfort, and increased frequency of posture changes. Subjects tried to maintain their defect detection performance over time by spending longer on each board, but they were only partially successful. In addition to providing positive evidence to justify the cost of ergonomic changes in posture, the results provide a simple and consistent set of measures to be used in future work.
Some Effects of Training on the Perception of Synthetic Speech
Authors: Schwab Eileen C. , Nusbaum Howard C. , Pisoni David B.
Published: July 2017

The present study was conducted to determine the effects of training on the perception of synthetic speech. Three groups of subjects were tested with synthetic speech using the same tasks before and after training. One group was trained with synthetic speech. A second group went through the identical training procedures using natural speech. The third group received no training. Although performance of the three groups was the same prior to training, significant differences on the post-test measures of word recognition were observed: the group trained with synthetic speech performed much better than the other two groups. A six-month follow-up indicated that the group trained with synthetic speech displayed long-term retention of the knowledge and experience gained with prior exposure to synthetic speech generated by a text-to-speech system.
Review and Evaluation of Empirical Research in Troubleshooting
Authors: Morris Nancy M. , Rouse William B.
Published: July 2017

Following an analysis of task requirements for successful troubleshooting, this paper considers human abilities. limitations, and inclinations with respect to troubleshooting. Research on the effects of various approaches to the training of troubleshooting is reviewed. The extent to which troubleshooting performance is influenced by instruction is highly related to the level of explicitness of action-related information provided. An approach that forces people to use their system knowledge explicitly is a promising alternative to explicit instruction in algorithms or diagnostic heuristics, but such an approach is not supported by data from transfer studies. A combination of the two approaches may be the most effective means of teaching troubleshooting, and research evaluating the soundness of this idea should be conducted.
An Integrated Display for Vertical and Translational Flight: Eight Factors Affecting Pilot Performance
Authors: Tatro Jon S. , Roscoe Stanley N.
Published: July 2017

As part of an overall research program to optimize both forward-looking and downward-looking tactical situation displays for all-weather instrument flight in vertical takeoff and landing (VTOL) aircraft, an integrated horizontal situation display was developed for both vertical and translational flight. This paper covers the development and initial experimentation of the downward-looking portion of the overall display and control system. The effects of eight factors on pilot performance were tested, and a multiple regression model of VTOL pilot performance as a function of those eight factors was derived for each of three dependent performance measures. Factors having important effects were position error magnification, control order, prediction time, control gain, tracking mode, and several of their interactions.
The Effectiveness of Stationary versus Moving Police Vehicles on Compliance with Speed Limit
Authors: Shinar David , Stiebel Jonathan
Published: July 2017

The absolute and relative effectiveness of conspicuously marked stationary and moving police units was studied, using a sample of 541 speeding drivers. Driver speeds were monitored prior to police detection, both at the site of the police unit and four km later. It was found that (1) the presence of police was sufficient to slow 95% of the speeding drivers, (2) the magnitude of initial speed reduction was the same in response to stationary and moving police units, (3) the halo effect (the tendency to maintain reduced speed after passing the police) was significantly greater for the drivers exposed to the moving units than to the stationary units, and (4) the greater the initial excess speed, the higher the final speed recorded after the police unit was passed. The results are consistent with the notion that compliance behavior is determined by the concept of perceived risk of apprehension.
Visual Fatigue and Spatial Frequency Adaptation to Video Displays of Text
Authors: Lunn Robert , Banks William P.
Published: July 2017

This article proposes that adaptation to the fundamental spatial frequency of lines of text on a video display terminal (VDT) provides a single explanation for a wide variety of reports of visual fatigue by VDT users. Reliable contrast threshold elevations at spatial frequencies of 2, 3, and 5 cycles/deg were found after subjects read single-spaced text on a VDT. This adaptation also reduces sensitivity to spatial frequencies in the range (2 to 6 cycles/deg) largely responsible for the reflexive accommodative response (Bour, 1981. Charman and Heron, 1979), and therefore could account for objective optometric measures of disturbed accommodation as well as some subjective effects of VDT viewing. Implications for video display design and for further research are discussed.
Maintenance Training Simulator Fidelity and Individual Differences in Transfer of Training
Authors: Allen John A. , Hays Robert T. , Buffardi Louis C.
Published: July 2017

This study was undertaken to investigate the relationship between simulator fidelity and training effectiveness. Two aspects of simulator fidelity were manipulated, namely, the degree to which a training simulator “looked like” actual equipment (physical fidelity), and the extent to which it “acted like” real equipment (functional fidelity). A transfer of training design was used to assess learning. Performance on an electromechanical troubleshooting task was correlated with a number of individual difference variables. Results indicated that physical and functional fidelity were interdependent and that temporal measures were most sensitive to fidelity manipulations. Low functional fidelity was associated with longer problem solution and inter-response times. Persons with high analytic abilities took longer to solve problems, but required fewer troubleshooting tests and made fewer incorrect solutions.
Beware the Reliability of Slope Scores for Individuals
Authors: Carter Robert C. , Krause Michele , Harbeson M. M.
Published: July 2017

This article examines the reliabilities (interday correlations) across 15 days of repeated measurements for each of five prominent human information-processing tasks: proactive memory interference, semantic reasoning, letter search, typographic error search, and choice reaction time. In each case, the reliability of the slope scores is less than the reliabilities of the mean response times from which the slopes were calculated. Reasons for the relative unreliability of slope scores are discussed. Finally, it is argued that in applied research it is usually unnecessary to calculate slope scores for individuals because the more reliable mean response times are sufficient to answer common applied questions.