2,547 research outputs found
A foldable 4.27 meter (14 foot) spacecraft antenna
The problems and solutions associated with the design, fabrication, and testing of a large, lightweight, radial-rib, folding, spacecraft antenna reflector are discussed. The antenna reflector was designed as a highly efficient communications system for outer-planet missions extending as far as approximately 59.839 x 10 to the 11th power meters (40 astronomical units) from the sun. The methods used to obtain a lightweight precision rib surface, the evaluation and fabrication of the metallic reflector mesh surface, and the surface-evaluation techniques used on the assembled antenna reflector are included
Traumatic brain injury in New Zealand: a silent epidemic?
In 2008 I was fortunate enough to be invited to be part of a research team on a large population based project focusing on the incidence and outcome of traumatic brain injury (TBI) in New Zealand (led by Professor Valery Feigin National Institute of Stroke and Applied Neurosciences, AUT University). At the time I knew little about TBI or population based research, but the last five years have changed that. My involvement in the project has led to on-going collaborations and friendships, and continues to provide me with on-going challenges as a researcher. More importantly, however, thanks to those who participated in our research, it has given me an enormous appreciation of the daily challenges faced by those affected by TBI and the desire to do research that ultimately will make a difference for them and other TBI survivors
Initial test bed concentrator characterization
The operational characteristics and the mirror alignment technique of the test bed concentrator control system are highlighted. The final design of the TBC control system provided one axis of fast slew capability so that either the Sun acquisition or emergency off-Sun mode could be obtained in a minimum time. The procedure for getting on and off Sun is to run the elevation axis up to the approximate elevation of the Sun for the particular time of acquisition and then slew the concentrator on Sun in azimuth. The automatic Sun-acquisition system is controlled by two Sun sensors, one for each axis; each has a 2deg acquisition cone angle within which the concentrators are programmed to point. The mirror alignment technique chosen utilized a semi-distant incandescent light source which produced a reflected image on the focal point target. The concentrator was boresighted to the light by moving the concentrator while sighting along the cross hairs and through the apertures in the disks to the light source resulting in a maximum point error of 0.11 deg. Test plans to install a solar flux mapper to characterize the solar spot and to measure the size, shape, and intensity of the Sun's image are outlined
The ‘frontal lobe’ project: A double-blind, randomized controlled study of the effectiveness of higher level driving skills training to improve frontal lobe (executive) function related driving performance in young drivers
The current study was undertaken in order to evaluate the effectiveness of higher level skills training on safe driving behaviour of 36 teenage drivers. The participants, who attended the Driver Training Research camp in Taupo (NZ) over a two week period, were 16 to 17 years old and had a valid restricted driver licence. The study focused on four main aims. Firstly, the behavioural characteristics of the sample and their attitudes to risk taking and driving were examined. Results showed that speeding was the most anticipated driving violation, and high levels of confidence were associated with a higher number of crashes and a greater propensity for risk taking. Many, often male participants, also rated their driving skills as superior to others and thought they would be less likely than others to be involved in an accident. Secondly, the relationship between driving performance and executive functioning, general ability and sustained attention was evaluated. Overall, better driving performance and more accurate self-evaluation of driving performance was related to higher levels of executive functions, in particular, working memory, and
cognitive switching. In addition, higher general ability and greater ability to sustain attention were also linked to better performance on the driving related assessments. The third focus of this study was to compare the effects of both, higher level and vehicle handling skills training on driving performance, confidence levels and
attitudes to risk. While both types of training improved direction control, speed
choice and visual search, along with number of hazards detected and actions in relation to hazards, statistically significant improvement on visual search was seen only after higher level skills training. Vehicle handling skills training significantly improved direction control and speed choice. In addition, confidence levels in their driving skills were significantly lowered and attitudes to speeding, overtaking and
close following had improved significantly in the participants after the higher level
driving skills training. The final aspect to this study was to examine the effects of the
training over the following 6 month period based on self-reported driving behaviour.
The response rate of participants however, was not sufficient to reach any meaningful conclusion on any long-term training effects. A pilot study using GPSbased data trackers to assess post-training driving behaviour revealed some promising results for future driver training evaluation studies. The overall implications of the results are discussed in relation to improving the safety of young
drivers in New Zealand
Evaluation of a sudden brake warning system: Effect on the response time of the following driver
This study used a video-based braking simulation dual task to carry out a preliminary evaluation of the effect of a sudden brake warning system (SBWS) in a leading passenger vehicle on the response time of the following driver. The primary task required the participants (N = 25, 16 females, full NZ license holders) to respond to sudden braking manoeuvres of a lead vehicle during day and night driving, wet and dry conditions and in rural and urban traffic, while concurrently performing a secondary tracking task using a computer mouse. The SBWS in the lead vehicle consisted of g-force controlled activation of the rear hazard lights (the rear indicators flashed), in addition to the standard brake lights. Overall, the results revealed that responses to the braking manoeuvres of the leading vehicles when the hazard lights were activated by the warning system were 0.34 s (19%) faster compared to the standard brake lights. The SBWS was particularly effective when the simulated braking scenario of the leading vehicle did not require an immediate and abrupt braking response. Given this, the SBWS may also be beneficial for allowing smoother deceleration, thus reducing fuel consumption. These preliminary findings justify a larger, more ecologically valid laboratory evaluation which may lead to a naturalistic study in order to test this new technology in ‘real world’ braking situations
The classification of substance and behavioural addictions: A preliminary investigation
The term addiction has been used to refer to impaired control over substance use for several centuries however recently there has been a shift toward using this term in the context of non-substance use disorders, such as pathological gambling. A preliminary investigation was conducted in an attempt to clarify the most appropriate classification of 'behavioural addictions'. Participants with alcohol dependence (AD, n = 24), pathological gambling (PG, n = 20) and compulsive buying disorder (CBD, n = 14) completed an Addictive Disorder Questionnaire (ADQ); the Symptom Checklist 90 Revised (SCL-90R); Barratt Impulsivity Scale II; and substance specific adaptations of the Yale-Brown Obsessive Compulsive Scale (Y-BOCS). Although the AD group reported more severe addiction symptoms and had higher levels of depression and anxiety, there were broad similarities across the three disorders in relation to cravings, dyscontrol, impulsivity and obsessions. Despite the small sample size and the different recruitment strategies used across the groups, the findings from this preliminary study provide support for broadening addiction diagnostic definitions to include non-substance related disorders which in turn may contribute to the development of more efficacious treatments
Does Familiarity breed inattention? Why drivers crash on the roads they know best
This paper describes our research into the nature of everyday driving, with a particular emphasis on the processes that govern driver behaviour in familiar, well - practiced situations. The research examined the development and maintenance of proceduralised driving habits in a high-fidelity driving simulator by paying 29 participants to drive a simulated road regularly over three months of testing. A range of measures, including detection task performance and driving performance were collected over the course of 20 sessions. Performance from a yoked control group who experienced the same road scenarios in a single session was also measured. The data showed the development of stereotyped driving patterns and changes in what drivers noticed, indicative of in attentional blindness and “driving without awareness”. Extended practice also resulted in increased sensitivity for detecting changes to foveal road features associated with vehicle guidance and performance on an embedded vehicle detection task (detection of a specific vehicle type). The changes in attentional focus and driving performance resulting from extended practice help explain why drivers are at increased risk of crashing on roads they know well. Identifying the features of familiar roads that attract driver attention, even when they are driving without awareness, can inform new interventions and designs for safer roads. The data also provide new light on a range of previous driver behaviour research including a “Tandem Model” that includes both explicit and implicit processes involved in driving performance
Telemetric longitudinal measurement of young driver behaviour
New Zealand is one of the few countries that currently allows teenagers to become solo drivers at 15 ½ years of age. During their first six months of solo driving, these teenagers are 19 times more likely to crash compared to the period of supervised driving. The behaviour of these adolescent drivers represents the single largest cause of fatalities in that age group and is widely acknowledged as one of the most serious social issues facing New Zealand. This state of affairs, often referred to as ‘the young driver problem,’ with an over representation of young drivers in motor vehicle crashes, is not unique to New Zealand. In fact, a similar situation can be found inmost of the world’s developed nations
Treatment for depression following mild traumatic brain injury in adults: A meta-analysis
Primary objective: Development of depression after TBI is linked to poorer outcomes. The aim of this manuscript is to review evidence for the effectiveness of current treatments.
Research design: Two meta-analyses were undertaken to examine the effectiveness of both pharmacological and non-pharmacological interventions for depression after mild TBI
Method and procedures: PubMed, Medline, PsychInfo, Web of Science and Digital Dissertations were searched and 13 studies located. Meta Analyst Beta 3.13 was used to conduct analyses of pre- vs post-effects then to examine treatment group vs control group effects.
Main outcomes and results: Studies using a pre–post design produced an overall effect size of 1.89 (95% CI = 1.20–2.58, p < 0.001), suggesting that treatments were effective; however, the overall effect for controlled trials was 0.46 (95% CI = −0.44–1.36, p < 0.001), which favoured the control rather than treatment groups.
Conclusions: This study highlights the need for additional large well-controlled trials of effective treatments for depression post-TBI
Further validation of the New Zealand test of adult reading (NZART) as a measure of premorbid IQ in a New Zealand sample
Premorbid IQ estimates are used to determine decline in cognitive functioning following trauma or illness. This study aimed to: 1) further validate the New Zealand Adult Reading Test (NZART) in a New Zealand population and compare its performance to the UK developed National Adult Reading Test, and 2) develop regression formulae for the NZART to estimate Wechsler Adult Intelligence Scale-IV (WAIS–IV) IQ scores. The 67 participants (53 females; 16 Māori), aged 16 to 90 years old (mean age = 46.07, SD 23.21) completed the WASI-IV, the NART and the NZART. The NZART predicted Verbal Comprehension Index (VCI) scores slightly better than the NART (r =.63 vs. r = .62) and explained 33% of the variance in FSIQ scores. Reasons for developing regression formulae for the NZART are discussed, regression formulas for the NZART based on the WAIS–IV are included and suggestions of alternate ways of determining premorbid IQ are made
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