bluuebunny/crossref_metadata_2025 huggingface dataset:
Determining Flight Task Proficiency of Students: A Mathematical Decision Aid
Authors: McDaniel William C. , Rankin William C.
Published: July 2017

Accurate appraisal of student performance during and after training is important for the proper functioning of the training system and realization of training goals. Training systems-and particularly flight training programs-rely heavily on expert assessors′ determination of student proficiency. Research is needed that will lead to improvements in the reliability and accuracy of these assessments. Recent research in decision making suggests that errors are frequently introduced because of the limited capabilities of people to integrate information and reach accurate conclusions. Mathematical decision aids appear to be helpful in reducing these errors. A decision aid using Wald's binomial probability ratio test and the sequential examination of student task performances was adapted to a training application. The decision aid required significantly less task trial information and predicted subsequent task performance more accurately than did expert assessors using the current assessment method. When students performed inconsistently and below the required flight task standards, instructors were more willing to declare proficiency than was the decision aid. This finding was especially apparent on the more difficult flight tasks.
Aurally Aided Visual Search in the Central Visual Field: Effects of Visual Load and Visual Enhancement of the Target
Authors: Perrott David R. , Sadralodabai Toktam , Saberi Kourosh , Strybel Thomas Z.
Published: July 2017

Visual search performance was examined in a two-alternative, forced-choice paradigm. The task involved locating and identifying which of two visual targets was present on a trial. The location of the targets varied relative to the subject's initial fixation point from 0 to 14.8 deg. The visual targets were either presented concurrently with a sound located at the same position as the visual target or were presented in silence. Both the number of distractor visual figures (0-63) present in the field during the search (Experiments 1 and 2) and the distinctness of the visual target relative to the distractors (Experiment 2) were considered. Under all conditions, visual search latencies were reduced when spatially correlated sounds were present. Aurally guided search was particularly enhanced when the visual target was located in the peripheral regions of the central visual field and when a larger number of distractor images (63) were present. Similar results were obtained under conditions in which the target was visually enhanced. These results indicate that spatially correlated sounds may have considerable utility in highinformation environments (e.g., piloting an aircraft).
Visual Monitoring with Spatially versus Temporally Distributed Displays
Authors: Payne David G. , Lang Virginia A.
Published: July 2017

Recent research has examined performance levels using rapid communication (RAP COM) visual displays. We extended this research in three experiments using a task in which subjects monitored visual displays representing dynamically varying system parameters and responded whenever an indicator value went beyond a specified range. In the spatial condition the indicator values were simultaneously presented in different locations on the CRT; in the RAP COM condition each indicator was presented in successive frames in a central location on the CRT. Results indicated that RAP COM displays yielded shorter response latencies than did spatial displays and that RAP COM displays produced significantly higher error rates. The same pattern was obtained with different stimulus-response mappings and across a range of practice levels. These findings indicate that RAP COM displays may not increase overall system performance, given the elevated error rates obtained with these displays. These error rate data indicate that it may not be possible to implement RAP COM displays in real-world systems. Possible reasons for the high error rate obtained with the RAP COM displays are discussed.
Divided Attention in Experienced Young and Older Drivers: Lane Tracking and Visual Analysis in a Dynamic Driving Simulator
Authors: Brouwer Wiebo H. , Waterink Wim , Van Wolffelaar Peter C. , Rothengatter Talib
Published: July 2017

A simulated driving task that required the simultaneous execution of two continuous visual tasks was administered to 12 healthy young (mean age 26.1 years) and 12 healthy older (mean age 64.4 years) experienced and currently active drivers. The first task was a compensatory lane-tracking task involving a three dimensional road display. The second task was a timed, self-paced visual analysis task involving either a vocal or manual binary response to dot patterns projected within the road display. Using adaptive tasks, single-task difficulty was individually adjusted for each subject. To control for individual differences in attention allocation strategy, the dual task was performed according to three different sets of instructions based on the relative importance of each task. Compared with young adults, older adults showed a significantly decreased ability to divide attention. This effect was apparent in lane tracking and in the accuracy of visual analysis. The impairment of divided attention was less pronounced in the vocal condition than in the manual one. This suggests that difficulty in integrating responses may be an important determinant of poor dual-task performance in old age.
Recent Changes in Driving among Older Adults
Authors: Barr Robin A.
Published: July 2017

Driving statistics comparing drivers aged at least 65 years with all drivers are examined for the years 1980 and 1989. In that time older driver fatalities had increased substantially despite a decrease in total driver fatalities. Analyses of size of population, numbers of licensed drivers, estimates of miles driven, and crash rates for these two years imply that the rise in total older driver deaths is related to increasing numbers of older adults who are licensed to drive and an increase in likelihood of fatality following a motor vehicle crash. This latter effect may be associated with a very substantial rise in the numbers of licensed drivers age 70 and older.
Strategy Guidance and Memory Aiding in Learning a Problem-Solving Skill
Authors: Carlson Richard A. , Lundy David H. , Schneider Walter
Published: July 2017

Guidance can help learners overcome the difficulties of getting started in a novel domain, but it is often ineffective in promoting learning and transfer. This article examines two aspects of guidance-communicating solution strategies for a problem domain and providing working memory support-in learning a novel problem-solving skill. Subjects in two experiments learned to troubleshoot simulated information networks. The learning environment varied in type of guidance provided-none, variable template, fixed template, and procedural instruction-and in availability of memory aiding. Variable-template guidance was effective when memory aiding was provided, and procedural instructions produced effective learning with or without memory aiding. However, fixed-template guidance was not effective, and there was no consistent effect of memory aiding in unguided, discovery learning conditions. The results have theoretical implications for the locus of guided-learning effects and suggest practical guidelines for the design of guided-learning environments.
Retention of Trained Performance in Consistent Mapping Search after Extended Delay
Authors: Fisk Arthur D. , Hodge Kevin A.
Published: July 2017

We examined the retention of performance in memory, visual, and hybrid memory/visual search after subjects received extensive consistent mapping (CM) practice. In the first two experiments we examined retention of detection performance in memory scanning (Experiment 1) and in visual search (Experiment 2) approximately one month after training. In the third experiment we examined performance 1, 30, 90, 180, and 365 days following training on pure visual and hybrid memory/visual semantic-category search tasks. We examined retention at intervals up to one year after practice as a function of amount of CM practice. In addition, we assessed the degree of category activation (performance on untrained words from the trained categories) at each retention interval. Across experiments, we found no decay in CM trained memory search and minimal decay in pure visual search. Significant decline in CM performance was largely attributable to performance in the hybrid memory/visual search conditions. These data reconcile previously equivocal retention results for CM trained search performance.
Refining the Test Phase of Usability Evaluation: How Many Subjects Is Enough?
Authors: Virzi Robert A.
Published: July 2017

Attention has been given to making user interface design and testing less costly so that it might be more easily incorporated into the product development life cycle. Three experiments are reported in this paper that relate the proportion of usability problems identified in an evaluation to the number of subjects participating in that study. The basic findings are that (a) 80% of the usability problems are detected with four or five subjects, (b) additional subjects are less and less likely to reveal new information, and (c) the most severe usability problems are likely to have been detected in the first few subjects. Ramifications for the practice of human factors are discussed as they relate to the type of usability test cycle employed and the goals of the usability test.
Principles for Measuring Teamwork Skills
Authors: Baker David P. , Salas Eduardo
Published: July 2017

Performance measurement research has characteristically focused on the performance of individuals and has not addressed the measurement of teamwork skills. Dyer Suggested that this lack of teamwork measures presents serious problems for conducting team-oriented research because research efforts are often judged by the quality of the measurement device employed. In an effort to assess and advance the science of measuring teamwork, the current review examines the measurement of teamwork skills on theoretical, methodological, and psychometric grounds. Furthermore, we present a series of general principles to guide research in the future. Although some progress has been made, there is still much to be learned about the measurement of teamwork.
Establishing Human Factors Criteria for Space Control Systems
Authors: Charlton Samuel G.
Published: July 2017

This paper describes the development of a human factors methodology and its application to the operational test and evaluation of space control systems. The method uses a correlational approach to link human factors measures to the mission effectiveness of space control systems. Experiment 1 describes an initial wide-spectrum attempt to identify human factors predictors of system performance. Based on the results of Experiment 1. the human factors measures and analysis method were refined and applied in the test of an operational satellite control system in Experiment 2. Experiment 3 applied the same methodology to a different satellite control system in order to determine the generalizability of the approach. The methodology worked with more than one system and was robust with respect to changes in personnel and location. The methodology was sensitive to changes in software, hardware, and procedures, and it yielded data that correctly reflected those changes.
Angle of Hard Copy and Text-Editing Performance
Authors: Brand Jay L. , Judd Kenneth W.
Published: July 2017

Three experiments evaluated the effect of angle of hard copy on text-editing performance. In the first, as the angular discrepancy between the hard copy and VDT screen increased, so did editing times and errors; experienced computer users generally outperformed naive users. The second experiment replicated the first but added text highlighting and a secondary task involving cancellation of a text/background screen reversal as factors. This study confirmed many of the results of the first. The secondary task response times showed consistent but nonsignificant effects of angle. Whether or not the line currently being edited was highlighted did not affect performance. The results of the third experiment suggested that having the hard copy orthogonal to the line of sight is important; in addition, it should also be adjacent to the VDT screen. These data argue for adjacent configurations that are normal to the line of sight. Subjective preferences generally supported this contention.
Motion Extrapolation Performance: A Linear Model Approach
Authors: Yakimoff Naum , Mateeff Stefan , Ehrenstein Walter H. , Hohnsbein Joachim
Published: July 2017

Researchers have obtained similar results from different visual motion extrapolation experiments despite the large variety of motion stimuli used. With respect to the ability of human subjects to judge the moment at which an occluded moving stimulus arrives at a predetermined position along its motion path, the general conclusion has been that errors increase with the duration of the occluded motion. However, substantial individual differences are often obscured within this statement. We propose a linear model to describe the performance of human observers in motion extrapolation tasks. The results from an experiment on centrifugal and centripetal motion extrapolation are examined in terms of this model. We discuss the restrictions imposed by the model on conclusions drawn after converting estimated arrival times to velocity estimates or accuracy scores. The parameters of the linear regression describing the individual performance in motion extrapolation tasks might be appropriate measures of interindividual differences.
Effects of Reduced Transmittance Film on Automobile Rear Window Visibility
Authors: Freedman Mark , Zador Paul , Staplin Loren
Published: July 2017

Deeply tinted window glass transmits less light than less deeply tinted glass and therefore reduces driver visibility. The task of looking through the rear window for hazards before backing a car was simulated in a laboratory setting with five targets (car, bicyclist, pedestrian, child, and debris) shown to drivers (ages 18-55, 56-75, and 76+) at various combinations of luminous transmittance of the windows and luminance (brightness) contrast of the targets. Analyses showed that the frequency of correct target detection varied by target. The car was always detected, but detection probability decreased with reduced luminous transmittance for the child and roadway debris targets. For the bicyclist, pedestrian, child, and debris targets, detection probability decreased with lower luminance contrast and for older age groups. The results suggest that the safety of backing maneuvers is compromised for all drivers at the darkest tinting levels studied. This is particularly true for elderly drivers for tinting levels darker than the 70% minimum luminous transmittance required by federal standards.
Effects of Part-Task Training on Memory Set Unitization and Retention of Memory-Dependent Skilled Search
Authors: Whaley Christopher J. , Fisk Arthur D.
Published: July 2017

Two experiments were conducted to examine the effects of part-task training on the acquisition and retention of a memory-dependent skill. Participants received extensive practice on a semantic category, memory/visual search task in one of three training conditions. To assess the effects of part-task training on memory element unitization, subjects trained on one third, one half, or all of the memory set elements during any given training session. Transfer tests requiring whole-task performance provided one index of training effectiveness. The results suggest that consistent memory sets can be unitized even if part-task training is used. Indeed, part-task training was as effective as whole-task training when immediate transfer was assessed. Part-task training produced retention performance equivalent to whole-task training when retention performance was determined by both target and distract or learning. Retention performance was superior for part-task training compared with whole-task training when performance was based on only target learning.
Effects of Three Types of Flight Simulator Visual Scene Detail on Detection of Altitude Change
Authors: Kleiss James A. , Hubbard David C.
Published: July 2017

The effects of three types of flight simulator visual scene detail on detection of altitude change were evaluated in three experiments. Across all experiments and with a variety of tasks and display conditions, speed and accuracy of detecting altitude change improved with increases in the density of vertical objects in scenes. Adding detail to individual objects to increase their natural appearance produced no consistent effects on performance. In Experiment 3 complex texture distributed globally on terrain surfaces improved detection of altitude change but did not alleviate the need for high object density. These results indicate that available computer image generator processing capacity would be used more effectively by increasing the density of objects in scenes, rather than by increasing the complexity and detail of individual objects. Complex texture is used more effectively when distributed globally on terrain surfaces, rather than when allocated to individual objects.
Acceptability of Intermittent Handgrip Contractions Based on Physiological Response
Authors: Byström Sven , Fransson-Hall Charlotte
Published: July 2017

Our aim was to study physiological response and acceptability of intermittent muscle contractions. Seven male subjects performed eight isometric handgrip exercises with altered contraction-relaxation periods but identical tension-time products. Local blood flow (BF), heart rate, blood pressure, electromyography, maximal voluntary handgrip contraction (MVC), and venous concentration of potassium and lactate of both forearms were followed during and up to 24 hours after the exercises. Wrist force response to electrical stimulation of a forearm muscle was used to investigate low-frequency fatigue (LFF). Ratings of perceived exertion were recorded during exercise. LFF was associated with a decreased functional capacity, which may be explained by a net potassium loss. Recovery BF was linearly related to mean contraction intensity of the experiments. Physiological criteria for acceptability of isometric exercise are suggested, based on the absence of fatigue during exercise and the return to baseline values within four hours of the recovery period. Based on these physiological criteria, intermittent hand grip contractions at (or higher than) a mean contraction intensity of 17% MVC and continuous handgrip contractions at (or higher than) 10% MVC were considered unacceptable.
Failure to Follow Safety Instructions: Faulty Communication or Risky Decisions?
Authors: Zeitlin Lawrence R.
Published: July 2017

The faulty communication versus risky decision hypotheses of failure to follow safety instructions were explored in a laboratory experiment. Four groups of 10 male college students differing in tool-using experience and safety orientation were asked to perform work sample activities with an electric chain saw. Safety orientation was provided by classroom lecture content. Dependent variables were compliance with safety warnings contained in the chain saw operating instructions and recognition of those instructions in a posttrial test. Understanding of instructions was verified by posttrial interview. Overall group compliance with the test safety instructions was 55.6%. Compliance for the group experienced with chain saws was 41.25%; for the inexperienced group it was 70%. An ANOVA showed both tool experience and safety orientation to be significant in influencing compliance. Instruction recognition was 87.5% overall with no difference between groups. Interviews revealed that the groups made an assessment of subjective risk dependent on their individual experience and safety orientation and acted accordingly.
Short Note Odor Identification by Name and by Edibility: Life-Span Development and Safety
Authors: De Wijk Renéa A. , Cain William S.
Published: July 2017

The study explored how subjects from childhood (8–14 years old) to elderly adulthood could identify the odors of 17 everyday products. Performance at naming followed an inverted U-shaped course over age, best in young adults and poorest in children and elderly. A discrimination task given to the adults revealed parallel age-related declines in ability to name and to discriminate odors. Correct identification by edibility exceeded that by name considerably. For dangerous household products, children achieved only 15% correct naming but 79% correct edibility/inedibility. Scenting of dangerous household products, however, may compromise the discriminability of these products from less harmful ones. "Fresh" -scented hypochlorite bleach yielded significantly more errors regarding its possible causticity than did unscented bleach. Such modifications of products would seem to necessitate other compensatory changes to enhance discriminability and thereby maintain safety.
Effect of Mailbag Design on Musculoskeletal Fatigue and Metabolic Load
Authors: Bloswick Donald S. , Gerber Ann , Sebesta David , Johnson Steve , Mecham William
Published: July 2017

The need for an alternative mailbag to the conventional U.S. postal mailbag, which hangs at the side over one shoulder, was investigated. Based on the results of a pilot study, two types of alternative mailbags, both including waist support and one that splits the load into two parts, are recommended. The metabolic energy requirement and lateral trunk muscle fatigue resulting from the use of the alternative mailbags were compared with those resulting from the conventional U.S. postal mailbag. The alternative mailbags resulted in no significant change in metabolic load. Both alternative mailbags resulted in significantly less lateral trunk muscle fatigue. It is proposed that this reduction in fatigue would result in reduced musculoskeletal stress and reduced potential for back injury.
Fatal Accidents among Car and Truck Drivers: Effects of Fatigue, Age, and Alcohol Consumption
Authors: Summala Heikki , Mikkola Timo
Published: July 2017

Fatigue increases the risk of an accident if the driver, on recognizing symptoms of fatigue, does not stop driving. We studied whether a tendency to continue the current activity and complete the task especially affects younger drivers, who are more susceptible to motivational pressures at the wheel in general. The data consisted of Finnish in-depth studies on 586 single-vehicle and 1357 multiple-vehicle accidents in which at least one vehicle occupant died. When excluding alcohol-related cases, the results showed that, first, trailer-truck drivers who either fell asleep or were tired to a degree that contributed to the accident were younger than those involved in the other fatalities. For car drivers, the proportion of fatigue-related cases was approximately constant in each age group, but a variation was seen when studied according to the time of day of the accident, mainly resulting from two distinct peaks. The first was in young drivers 18 to 20 years old between midnight and 6:00 a.m. The other occurred in drivers 56 years and older during the late afternoon hours. These data also indicate that in terms of fatal accidents, fatigue and alcohol seem to be less of a problem for truckers than for car drivers.
Speech Intelligibility and Protective Effectiveness of Selected Active Noise Reduction and Conventional Communications Headsets
Authors: Gower Daniel W. , Casalvi John G.
Published: July 2017

An experiment was conducted to compare both speech intelligibility and noise attenuation of a conventional passive headset (David Clark H10-76) and an electronic Active Noise Reduction (ANR)headset (Bose Aviation) operated with and without its ANR feature. Modified Rhyme Tests were conducted in pink and tank noise, and with and without bilateral phase reversal between earphones. The Bose ANR unit required a significantly higher speech-to-noise (S/N) ratio in both noise environments than the two passive headset systems to maintain equal intelligibility, in part because of its stronger noise reduction and higher required signal level. Articulation Index calculations corroborated the empirical result that the David Clark afforded comparable intelligibility to the Bose ANR device. Bilateral phase reversal proved to be of no benefit, and pink noise proved to be the harsher environment for speech intelligibility. On a speech intelligibility basis alone, the results do not justify the additional cost of the ANR headset; however, when severe noise exposure is at issue, a properly functioning ANR unit may afford more protection than a similar passive headset without electronics, especially in low-frequency noise spectra.
A Componential Model of Human Interaction with Graphs: 1. Linear Regression Modeling
Authors: Gillan Douglas J. , Lewis Robert
Published: July 2017

Task analyses served as the basis for developing the Mixed Arithmetic-Perceptual (MA-P)model, which proposes (1) that people interacting with common graphs to answer common questions apply a set of component processes-searching for indicators, encoding the value of indicators, performing arithmetic operations on the values, making spatial comparisons among the indicators, and responding; and (2) that the type of graph and user's task determine the combination and order of the components applied (i.e., the processing steps). Two experiments investigated the prediction that response time will be linearly related to the number of processing steps according to the MA-P model. Subjects used line graphs, scatter plots, and stacked bar graphs to answer comparison questions and questions requiring arithmetic calculations. A one-parameter version of the model (with equal weights for all components) and a two-parameter version (with different weights for arithmetic and nonarithmetic processes) accounted for 760%-85%of individual subjects' variance in response time and 61%-68% of the variance taken across all subjects. The discussion addresses possible modifications in the MA-P model, alternative models, and design implications from the MA-P model.
Influence of Warning Label Signal Words on Perceived Hazard Level
Authors: Wogalter Michael S. , Jarrard Stephen W. , Simpson S. Noel
Published: July 2017

This experiment investigated the influence of warnings, signal words, and a signal icon on perceived hazard of consumer products. Under the guise of a marketing research study, 135 people (high school students, college students, and participants from a shopping mall) rated product labels on six dimensions, including how hazardous they perceived the products to be. A total of 16 labels from actual household products were used: 9 carried the experimental conditions, and 7 were filler product labels that never carried a warning. Five conditions presented the signal words NOTE, CAUTION, WARNING, DANGER, and LETHAL together with a brief warning message. In another two conditions, a signal icon (exclamation point surrounded by a triangle) was presented together with the terms DANGER and LETHAL. In the final two conditions, one lacked a signal word but retained the warning message, and the other lacked both the warning message and the signal word. Results showed that the presence of a signal word increased perceived product hazard compared with its absence. Significant differences were noted between extreme terms (e.g., NOTE and DANGER) but not between terms usually recommended in warning design guidelines (e.g., CAUTION and WARNING). The signal icon showed no significant effect on hazard perception. Implications of the results and the value of the methodology for future warnings investigations are discussed.
Minimalism and the Syntax of Graphs
Authors: Gillan Douglas J. , Richman Edward H.
Published: July 2017

Four experiments examined Tufte's syntactic rule that graphs should have maximal data-ink ratios produced by erasing non-data-ink and redundant data-ink. In Experiment 1, the data-ink ratios of bar and line graphs affected the accuracy and response times for comparison, difference, and mean questions: the higher the data-ink ratio, the faster the response time and the greater the accuracy. Experiments 2 and 3 showed that the effects of ink in the syntactic elements of a graph depend on the location and function of the element: redundant ink in the indicators had limited effects on performance, pictorial backgrounds generally increased response time and decreased accuracy, y axis tick marks generally increased response time, and the y axis line and the x axis generally decreased response time. The effect of each graphical element was conditional on the type of graph and task and the presence of other graphical elements. The discussion focuses on psychological principles that may underlie the effects of each syntactic element.
Tactile Stimulation of the Human Head for Information Display
Authors: Gilliland Kirby , Schlegel Robert E.
Published: July 2017

A series of three studies was conducted to explore the use of tactile stimulation or light tapping of the human head to inform a pilot of possible threats or other situations in the flight environment. Study I confirmed that subjects could achieve 100% detection of the tactile stimuli. Localization performance, measured in Study 2, depended on the number of different stimulus sites and ranged from 93% accuracy for 6 sites to 47% accuracy for 12 sites across the parietal meridian of the head. In Study 3 we investigated the effect of performing the localization task simultaneously with a dual memory/tracking task or an air combat simulation task. These studies demonstrated that tactile information display could be an integral contributor to improved situation awareness, but not without cost to other task performance. The results of Study 3 were also examined with reference to popular models of attention and workload.
National e-government performance and citizen satisfaction: a multilevel analysis across European countries
Authors: Ma Liang , Zheng Yueping
Published: July 2017

Are citizens more satisfied with e-government ranked higher in league tables? In this article, we empirically examine the relationship between objective e-government performance on the supply side and the perceptions of citizens on the demand side. A multilevel analysis of over 28,000 respondents across 32 European countries reveals that highly ranked e-government is warmly welcomed by citizens, suggesting that the supply and demand sides of e-government are, in part, consistent. Specifically, the e-government performance–satisfaction correlations in e-service and e-participation are more prominent than that of e-information. The results also show that citizens’ perceived e-government benefits are mainly from using online services. While e-government rankings are reasonably predictive of citizen satisfaction, they should be referred to with caveats in e-government policies.

Points for practitioners

The empirical findings reveal that objective e-government performance is partially congruent with citizens’ satisfaction and perceived benefits. While e-government rankings may not be good predictors of citizen use, they do coincide, in part, with citizen satisfaction. Ubiquitous e-government benchmarks can be referred to as reliable gauges of citizen satisfaction, though their susceptibility varies across the purposes of e-government use. The various benefits that citizens perceived from e-government are primarily derived through online services instead of electronic information or participation, and the government should pay more attention to e-service development in order to bring more benefits to its users.
Laminate Plate Theory for Spatially Distributed Induced Strain Actuators
Authors: Wang Bor-Tsuen , Rogers Craig A.
Published: July 2017

Classical laminated plate theory (CLPT) is applied to a laminate plate with induced strain actuators, such as piezoceramic patch, bonded to its surface or embedded within the laminate to develop an induced strain actuation theory that allows for the actuator patch to be spatially distributed. When piezoceramic patches are subjected to voltage fields, the equivalent external forces induced by piezoceramic patches can be determined upon the assumption of free constraint for the expansion or contraction of piezoceramic patches. This assumption is generally done in thermal expansion problem. Several examples, including pure bending and pure extension, are illustrated. For the case of pure bending, a comparison between the current work and that of Dimitriadis et al. (1989) is given. In addition, an orthotropic angle-ply laminate with an embedded piezoceramic patch is presented to show the coupling of bending and extension.
Buckling of Unidirectional Composites Containing Noncircular Fibers: Part I—Elliptical Sections
Authors: Tan Seng C.
Published: July 2017

A micro-macro approach is developed to study the critical buckling stress of unidirectional composite laminates containing continuous fibers with circular or noncircular shape in cross section. The fiber volume fraction of the laminates, the slanted angle of the noncircular fibers and the distribution probability of the slanted angle are taken into consideration. The method of solutions is generally derived for unidirectional composites containing noncircular fibers of any shape. In particular, solutions are given for laminates containing circular fibers or elliptical fibers in part 1 of these papers. The solution of laminates containing elliptical fibers shows that the critical buckling stress can be either better or worse than that containing circular fibers under certain conditions. Parametric studies are presented to reveal the important factors associated with the critical buckling stress problem.
A Model of the Resin Impregnation in Thermoplastic Composites
Authors: Seo Jeong Wook , Lee Woo Il
Published: July 2017

Impregnation of thermoplastic resin into continuous unidirectional fiber tows was investigated. A power-law was employed to describe the effect of the shear rate on the viscosity of the molten resin. The effect of the impregnation pressure on the permeability of the fiber tow was also taken into consideration. The degree of impregnation was defined as the ratio between the number of impregnated fibers and the total number of fibers of a tow. A model was developed to describe the degree of impregnation as a function of time, pressure, temperature and tow size. The radial inward flow of resin through the fiber tow was assumed to be a flow through porous media and thus governed by Darcy's law. Experiments were performed to evaluate the validity of the model for different impregnation conditions such as impregnation time, pressure, temperature and tow size. From microphotographs of the cross-sections of the samples obtained from the experiments, the degree of impregnation was measured. Good agreement was found between the model and the experimental data.
Effect of Fiber Architecture Parameters on Deformation Fields and Elastic Moduli of 2-D Braided Composites
Authors: Naik Rajiv A. , Ifju Peter G. , Masters John E.
Published: July 2017

The effects of various braiding parameters for 2-D triaxially braided textile composites were systematically investigated both experimentally and analytically. Four different fiber architectures designed to provide a direct comparison of the effects of braid angle, yarn size and axial yarn content were tested. Moiré interferometry was employed to study the effect of these parameters on the surface strain fields in the material. Moiré results for the surface strain fields were found to be strongly influenced by all of the three parameters. Larger yarn sizes led to higher normal strains and led to early cracking under transverse loading. Increasing the axial yarn content by using larger axial yarns also led to premature cracking under transverse loading. The mechanical tests showed that stiffness properties were not a function of yarn size. However, they were strongly influenced by braid angle and axial yarn content. A simple analysis that explicitly models the fiber architecture was developed. The analysis technique successfully predicted mechanical properties and also the trends in the test data. Increasing the braid angle led to decreasing longitudinal modulus, increasing transverse modulus, and in-plane shear modulus values that peaked for a braid angle of ±45°. Increasing the axial yarn content led to increasing longitudinal modulus, decreasing in-plane shear modulus and Poisson's ratio values. Out-of-plane Young's modulus and shear moduli were insensitive to variations in braid angle and axial yarn content. Composite properties were found to be more sensitive to variability in braid angle than to variations in axial yarn content.
Detaining the Dangerous: Legal and Ethical Implications of the Government's Proposals for High-Risk Individuals
Authors: Laing Judith M.
Published: July 2017

In December 2000, the government in England and Wales published a White Paper proposing a radical overhaul of current mental health legislation. Part II of the White Paper contained controversial new proposals to detain indefinitely ‘high-risk’ disordered individuals. These proposals have attracted a large amount of criticism in both legal and medical circles and may contravene the European Convention on Human Rights. This article will outline the proposals for reform and highlight some of the legal and ethical implications, in particular focusing on the extent to which the proposals may be open to challenge under the Human Rights Act 1998.
Is the Utility of Secondary Coping a Function of Ethnicity or the Context of Reception? A Longitudinal Study Across Western and Eastern Cultures
Authors: Szabo Agnes , English Alexander S. , Zhijia Zeng , Jose Paul , Ward Colleen , Jianhong Ma
Published: July 2017

Although cross-cultural research suggests that the development and functionality of secondary coping strategies are substantially influenced by the broader cultural context, research findings are not completely conclusive. Some studies indicate that secondary coping is more adaptive for Asian participants compared with Westerners, while others emphasize the adaptability of the coping style in Asian, but not Western, contexts. The main objective of the present study was to systematically test for ethnic and contextual differences in the effectiveness of secondary strategies (measured in the form of acceptance and positive reinterpretation) in reducing the negative effects of acculturative stress on somatic symptoms with samples of international students. A 3-month longitudinal study was conducted in two different contexts: (a) Asian and Western international students in China (Asians: n = 53, Westerners: n = 51) and (b) similar groups in New Zealand (Asians: n = 61, Westerners: n = 65). The data were subjected to a hierarchical regression analysis with changes in psychological symptoms functioning as the dependent variable. Findings indicated that stress, secondary coping, and cultural context significantly interacted in predicting changes in somatic symptoms. Specifically, secondary coping exacerbated the negative effects of acculturative stress on psychological adjustment in New Zealand. In contrast, secondary coping functioned as a buffer in China, such that it was effective at reducing the negative impact of stress over time. Findings indicated that ethnicity did not significantly moderate the stress–coping–adjustment relationship. Our results show that the effectiveness of secondary coping varies as a function of the cultural context.
Community Context and Child Health: A Human Capital Perspective
Authors: Smith-Greenaway Emily
Published: July 2017

Human capital theory suggests that education benefits individuals’ and their children’s health through the educational skills people acquire in school. This perspective may also be relevant at the community level: the greater presence of adults with educational skills in a community may be a reason why living in a more highly educated setting benefits health. I use Demographic and Health Survey data for 30 sub-Saharan African countries to investigate whether the percentage of literate adults—specifically women—in a community is associated with children’s likelihood of survival. I characterize 13,785 African communities according to the prevalence of women who are literate. Multilevel discrete-time hazard models ( N = 536,781 children) confirm that living in a community where more women are literate is positively associated with child survival. The study supports the conceptualization of literacy, and potentially other educational skills, as forms of human capital that can spill over to benefit others.
MAWRID: A Model of Arabic Word Reading in Development
Authors: Saiegh-Haddad Elinor
Published: July 2017

This article offers a model of Arabic word reading according to which three conspicuous features of the Arabic language and orthography shape the development of word reading in this language: (a) vowelization/vocalization, or the use of diacritical marks to represent short vowels and other features of articulation; (b) morphological structure, namely, the predominance and transparency of derivational morphological structure in the linguistic and orthographic representation of the Arabic word; and (c) diglossia, specifically, the lexical and lexico-phonological distance between the spoken and the standard forms of Arabic words. It is argued that the triangulation of these features governs the acquisition and deployment of reading mechanisms across development. Moreover, the difficulties that readers encounter in their journey from beginning to skilled reading may be better understood if evaluated within these language-specific features of Arabic language and orthography.
‘Alcohol Intoxication’ or ‘Drunkenness’: Is There a Difference?
Authors: Rix Keith J. B.
Published: July 2017

The terms ‘alcohol intoxication’ and ‘drunkenness' have hitherto been used interchangeably. A distinction between these terms is justified. Anthropological research suggests that the behaviour displayed by people who have consumed alcohol has more to do with culturally-determined expectations than with the properties of alcohol. Subjects who believe they have consumed alcohol when they have not behave more aggressively than those who believe that they have not consumed alcohol. There are significant false-positive and false-negative rates when doctors use clinical signs to judge whether or not a patient is intoxicated. People who die in police custody after arrest for offences of drunkenness include a porportion who have a negligible quantity of alcohol in the body and whose cause of death is unrelated to alochol.

It is proposed: (1) that the term ‘alcohol intoxication’ should refer to a state in which alcohol is present in the body; (2) its diagnosis should be based on toxicological evidence for the presence of alcohol in body fluids or tissues; and (3) the term ‘drunkenness' should be used to describe behaviour displayed by people who have consumed, believe that they have consumed, or want others to believe that they have consumed, alcohol. Some clinical and legal implications of this distinction are discussed.
Children's Memories for Stressful and Non-Stressful Events
Authors: Oates Kim , Shrimpton Sandra
Published: July 2017

Two groups of children aged between 4 and 12 years were studied to look at the effect of stress, time and type of questioning on memory. One group comprised 17 children having a blood sample taken as part of their medical care. The other group of 24 children were studied after reacting with a friendly stranger at their school. Memory was tested either four to ten days after the event or after three to six weeks. Memory was assessed by free recall, by questioning with cues, by structured questions, by leading or misleading questions and by asking the children to identify the blood-collection technician or friendly stranger from a photographic line-up. There was no difference between memory for the stressful or non-stressful events. The older children performed better in free recall although what the younger children did recall was highly accurate. The use of cues facilitated recall in all age groups. Children aged four to six years were less accurate than those aged seven to 12 years when objective questioning was used. Errors were more likely to be errors of omission than of commission in all age groups. Memory was less accurate after the longer time interval. With increasing interest in the reliability of children as witnesses, methods need to be found which will enable the child witness to give the maximum amount of accurate information. Those likely to be working with the child witness need to develop skills in talking with young children.
How Informed are Community Psychiatric Nurses (CPNs) of Their Role in the Implementation of Supervised Discharge?
Authors: Saggers Julie , McClelland Norman
Published: July 2017

A questionnaire was delivered to community psychiatric nurses (CPNs) (n=23) in order to determine whether they had received adequate training in relation to the 1995 Mental Health (Patients in the Community) Act. Data collected were analyzed. The findings suggest that there is a lack of knowledge in relation to the documentation. The research suggests that more formal training in relation to policy documents should be provided by employers.
Lateralization of Perceptual Closure Ability
Authors: Fouty H. Edward , Yeo Ronald A.
Published: July 2017

The present study investigated lateralization of perceptual closure ability. A zero-power, partially occluded, soft contact-lens system was used to lateralize visual input. This technique has been shown to create reliable artificial visual-field deficits when used in situations offering unlimited duration of stimulus exposure. The Street Gestalt Completion Test was administered to 18 right-handed men with no history of head trauma, neurological disorders, or familial sinistrality. Using repeated-measures analyses, and controlling for age, we found no significant hemispheric advantage for either speed or accuracy of performance.
Measuring Women’s Empowerment and Poverty Reduction: Experiences of Hanji Women in Kashmir
Authors: Rather Tareak A. , Bhat Mohd. Aslam
Published: July 2017

The empowerment of women in Jammu and Kashmir as elsewhere in India, no doubt, has been part of the development planning process and has helped improving the status of the state’s women in various spheres, but serious challenges still remain on the ground, and this is more so in case of the women of marginalised communities, such as Hanji (fisher). This article presents an attempt to locate the status of Hanji women of Kashmir from sociocultural standpoints, and gives an analysis of their economic contributions towards poverty reduction at familial and household level. The empirical evidence analysed reveals that majority of Hanji women despite being low at some major parameters of empowerment, were playing variety of hand to elevate their families socially and economically.
Institution of Dzumsa in North Sikkim: A Sociological Understanding
Authors: Thapa Sandhya , Sachdeva Swati A.
Published: July 2017

Despite the introduction of Panchayat Raj Institution in rest of Sikkim, Lachen and Lachung, two villages in North Sikkim have still retained the traditional system of self-governance called Dzumsa. The article brings out how despite the penetration of forces of modernisation, the institution still persists as an effective mode of self-governance system fairly accommodating the developmental roles in the new democratic set up in the state. The article concludes by saying how the mechanical solidarity and collective consciousness in the Durkheimian an sense and Parsonian pattern variable of collective-orientation and particularism still remains intact although faint changes are being noticed in the institution.
Book Review: B. B. Mohanty (ed.), Critical Perspectives on Agrarian Transition: India in the Global Debate
Authors: Thakur Manish
Published: July 2017

B. B. Mohanty (ed.), Critical Perspectives on Agrarian Transition: India in the Global Debate. New Delhi: Routledge, Taylor and Francis, 2016, xxviii + 300 pp., ₹895 (hardback), ISBN: 978-1-138-66860-7.