Broadband sparse sensing : a polynomial matrix approach to co-prime and super nested arrays

Passively monitoring the spectrum for detection and localisation of radar sources is ever more fraught with difficulty due to the advent of low probability of intercept (LPI) radar technology. A key aspect of LPI radar waveform design are the spread spectrum modulation schemes; instead of concentrating power over a narrow-bandwidth, this power can be spread across a broad-bandwidth making the source difficult to detect using conventional ESM methods. Such sources prompt the need for new detection, and direction of arrival estimation methods. Moreover, broadband antennas and their subsequent processing systems are expensive in terms of both cost and power-forcing a real world feasible limit on the number of antennas in a system. In addition, a fine spacing is required for ambiguity free direction of arrival estimation of higher frequency sources while a wide aperture is required for sufficient resolution of lower frequency sources. In this paper we present a novel sparse broadband direction of arrival method based upon co-prime and super-nested array geometries, using polynomial matrix methods whereby a new virtual array is formed containing many more virtual elements than in the physical array

Taking a break: The effect of taking a vacation from Facebook and Instagram on subjective well-being

Social Networking Sites (SNS) such as Facebook and Instagram have relocated a large portion of people's social lives online, but can be intrusive and create social disturbances. Many people therefore consider taking an "SNS vacation." We investigated the effects of a one-week vacation from both Facebook and Instagram on subjective well-being, and whether this would vary for passive or active SNS users. Usage amount was measured objectively, using RescueTime software, to circumvent issues of self-report. Usage style was identified at pre-test, and SNS users with a more active or more passive usage style were assigned in equal numbers to the conditions of one-week SNS vacation (n = 40) or no SNS vacation (n = 38). Subjective well-being (life satisfaction, positive affect, and negative affect) was measured before and after the vacation period. At pre-test, more active SNS use was found to correlate positively with life satisfaction and positive affect, whereas more passive SNS use correlated positively with life satisfaction, but not positive affect. Surprisingly, at post-test the SNS vacation resulted in lower positive affect for active users and had no significant effects for passive users. This result is contrary to popular expectation, and indicates that SNS usage can be beneficial for active users. We suggest that SNS users should be educated in the benefits of an active usage style and that future research should consider the possibility of SNS addiction among more active users

Genetic and Environmental Influences on Literacy and Numeracy in Australian School Children

Each year, Australian students in Grades 3, 5, 7, and 9 sit nationwide tests in literacy and numeracy. These tests inform government, principals, and parents about student, school, and state performance in five domains: reading, spelling, grammar and punctuation, writing, and numeracy. As such, the results of these tests are of wide interest for diverse reasons depending on the stakeholder in question. In this thesis I examine the influence of genes and the environment on individual differences in performance on these tests. Using longitudinal data collected from a large sample of Australian twins and their siblings.
 Initially, as a test of validity, I compared the performance of large-scale reading tests against three literacy tests in comprehension, word reading and vocabulary individually administered to twins in Grade 3. The individually administered tests accounted for a substantial amount of the variance in the large-scale reading tests. Additionally, they were preferentially related, both genetically and environmentally, to large-scale reading tests compared to large-scale numeracy tests, confirming that large-scale school reading tests measure, at least in part, the literacy skills tapped by individual tests considered “gold-standard” in testing.
 In the second paper, I examined the extent to which genes and the environment contributed to variation in and covariation among the five domains in each grade. Averaged across domains and grade, genetic factors explained 60%, shared environment 10%, and unique environment 30% of the variation. Independent pathway models showed similar genetic and environmental structures at each grade with approximately one third to one half of the variation in each domain due to genes that influenced all domains.
 In the third paper, I explored the genetic and environmental influences on stability and growth in each of the domains. Stability in performance was primary due to genes. For growth, reading followed a compensatory growth pattern, and variation in growth was due to the genes that also influenced differences in performance at initial testing. By contrast, growth in numeracy was principally influenced by unique environmental factors. These results suggest individual differences in growth of reading are primarily due to a genetically influenced developmental delay in the acquisition of necessary skills, while for numeracy, differences are due to environmental influences, such as different teachers or interests.
 In the fourth paper, I tested if family or school SES moderated heritability of performance. Genetic influence was substantial and stable across all levels of family and school SES, with some evidence of a stronger influence of the shared environment when SES was lower, particularly for Grade 3 literacy. A final chapter presents a discussion summarising the principal findings, their implications, and their limitations

The Etiology of Individual Differences in Second Language Acquisition in Australian School Students: A Behavior‐Genetic Study

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/93553/1/j.1467-9922.2012.00718.x.pd

Genetic and Environmental Influences on Perceived Social Support: Differences by Sex and Relationship

Previous research has shown that self-reports of the amount of social support are heritable. Using the Kessler perceived social support (KPSS) measure, we explored sex differences in the genetic and environmental contributions to individual differences. We did this separately for subscales that captured the perceived support from different members of the network (spouse, twin, children, parents, relatives, friends and confidant). Our sample comprised 7059 male, female and opposite-sex twin pairs aged 18−95 years from the Australian Twin Registry. We found tentative support for different genetic mechanisms in males and females for support from friends and the average KPSS score of all subscales, but otherwise, there are no sex differences. For each subscale alone, the additive genetic (A) and unique environment (E) effects were significant. By contrast, the covariation among the subscales was explained - in roughly equal parts - by A, E and the common environment, with effects of different support constellations plausibly accounting for the latter. A single genetic and common environment factor accounted for between half and three-quarters of the variance across the subscales in both males and females, suggesting little heterogeneity in the genetic and environmental etiology of the different support sources

GNSS based passive radar for UAV monitoring

Monitoring of unmanned aerial vehicle (UAV) targets has been a subject of great importance in both defence and security sectors. In this paper a novel system is introduced based on a passive bistatic radar using Global Navigation Satellite Systems (GNSS) as illuminators of opportunity. Particularly, a link budget analysis is held to determine the capabilities and limitations of such a system. Additionally, a signal reconstruction algorithm is provided allowing estimation of the transmitted signal from each satellite. Finally, the proposed system is tested in outdoor acquisitions of small UAV targets where the Fractional Fourier Transform (FrFT) is used as tool to enhance target detectability

The Humber and North Yorkshire Green Social Prescribing Programme Cohort Evaluation

There is a strong body of evidence that points to the mental health and wellbeing benefits of nature alongside a growing evidence base on the health and wellbeing benefits of green social prescribing (GSP). Central to the UK government’s commitment to transform mental health services, increase social prescribing (SP), and deliver personalised care, seven successful ‘test and learn’ GSP sites were identified across England, including the Humber and North Yorkshire (HNY) GSP programme. The aim of the ‘test and learn’ sites was to embed GSP into communities to improve mental health outcomes, reduce health inequalities, reduce demand on the health and social care system, and develop best practice in making green social activities more resilient and accessible. This report summarises the findings of the cohort evaluation, a key component of the HNY GSP programme, and reports on the mental health and wellbeing outcomes of participants who took part in nature-based activities linked to the GSP initiative. It discusses the findings in relation to the wider literature, key challenges identified by referring services involved in the cohort evaluation, alongside clinical implications, and future research opportunities in the area of GSP

Measuring CHAOS? Evaluating the short-form Confusion, Hubbub And Order Scale

The Confusion, Hubbub and Order Scale (CHAOS) – short form – is a survey tool intended to capture information about home environments. It is widely used in studies of child and adolescent development and psychopathology, particularly twin studies. The original long form of the scale comprised 15 items and was validated in a sample of infants in the 1980s. The short form of the scale was developed in the late 1990s and contains six items, including four from the original scale, and two new items. This short form has not been validated and is the focus of this study. We use five samples (N=10,898) from studies in Australia, the UK, and the USA, to examine the measurement properties of the CHAOS short form. We first compare alternate confirmatory factor models for each group; we next test between-group configural, metric and scalar invariance; finally, we examine predictive validity of the scale in each sample under different conditions. We find evidence that a two-factor configuration of the six items is more appropriate than the commonly used one-factor model. Second, we find measurement non-invariance across groups at the metric invariance step, with items performing differently depending on the sample. By contrast we find longitudinal measurement invariance in two of the three samples with multi-wave data collection on the CHAOS. Finally, we report inconsistent results in tests of predictive validity using family-level socioeconomic status and academic achievement as criterion variables. The results caution the continued use of the short-form CHAOS in its current form and recommend future revisions and development of the scale for use in developmental research

Identical Genes, Unique Environments: A Qualitative Exploration of Persistent Monozygotic-Twin Discordance in Literacy and Numeracy

This study aimed to explore unique environmental factors impacting differential academic trajectories among Australian school students. Monozygotic (MZ) twin pairs who were consistently discordant in results of nationwide standardized tests of reading, numeracy or writing between Grades 3 and 9 were identified. MZ twins control for genes, gender, age, and aspects of the home and school environment shared by twins. Thus, any difference between MZ twins in academic outcomes can be attributed to the unique environment experienced by each twin. From 551 MZ twin pairs with three or four sets of test results, we identified 55 pairs who were substantially and consistently discordant in reading, numeracy or writing between Grades 3 and 9. Parents were contacted for interview, resulting in 40 semi-structured interviews. Qualitative data analysis revealed three major themes, interpreted by parents as possible contributors to persistent academic discordance: biological mechanisms, school-based factors, and personal factors. We discuss implications for educational practice, policy, and research