Accuracy of estimating the masses of Phobos and Deimos from multiple Viking orbiter encounters

The problem was investigated of estimating the masses of Phobos and Deimos from Doppler and onboard optical measurements during the Viking extended mission. A Kalman filter was used to analyze the effects of gravitational uncertainties and nongravitational accelerations. These accelerations destroy the dynamical integrity of the orbit, and multibatch or limited memory filtering is preferred to single batch processing. Optical tracking is essential to improve the relative orbit geometry. The masses can be determined to about 10% and 25% respectively for Phobos and Deimos, assuming satellite densities of about 3 gr/cu cm

The relationship between engineering bachelor qualifications and occupational status in Australia

Internationally, the importance of science, technology, engineering and mathematics (STEM) for innovation and competition drives concerns about the adequacy of national STEM workforces. Data from the UK, USA and Australia suggest that, even immediately post-graduation, a significant proportion of engineering bachelor graduates do not work in engineering roles. Using the 2011 Australian census data, we present an investigation into the relationship between educational qualifications and occupational status of Australian engineering bachelor graduates, and how this status varies specifically with graduate age. We consider the implications of these findings and present recommendations for the recruitment and education of Australian engineering undergraduates. We conclude that engineering students would be better informed about, and equipped for, the world of post-graduation work if they were exposed to the likely options for their career trajectory. Likewise, secondary school students and others considering engineering undergraduate study would be more honestly advised if they were informed about the full range of career possibilities for engineering graduates and the probability that they are just as likely to work out of engineering as in it

LIDAR-Aided Inertial Navigation with Extended Kalman Filtering for Pinpoint Landing

In support of NASA s Autonomous Landing and Hazard Avoidance Technology (ALHAT) project, an extended Kalman filter routine has been developed for estimating the position, velocity, and attitude of a spacecraft during the landing phase of a planetary mission. The proposed filter combines measurements of acceleration and angular velocity from an inertial measurement unit (IMU) with range and Doppler velocity observations from an onboard light detection and ranging (LIDAR) system. These high-precision LIDAR measurements of distance to the ground and approach velocity will enable both robotic and manned vehicles to land safely and precisely at scientifically interesting sites. The filter has been extensively tested using a lunar landing simulation and shown to improve navigation over flat surfaces or rough terrain. Experimental results from a helicopter flight test performed at NASA Dryden in August 2008 demonstrate that LIDAR can be employed to significantly improve navigation based exclusively on IMU integration

Masculinity at work: The experiences of men in female dominated occupations

This paper presents the findings of a research project on the implications of men's non-traditional career choices for their experiences within the organization and for gender identity. The research is based on 40 in-depth interviews with male workers from four occupational groups: librarian-ship, cabin crew, nurses and primary school teachers. Results suggest a typology of male workers in female dominated occupations: seekers (who actively seek the career), finders (who find the occupation in the process of making general career decisions) and settlers (who settle into the career after periods of time in mainly male dominated occupations). Men benefit from their minority status through assumptions of enhanced leadership (the assumed authority effect), by being given differential treatment (the special consideration effect) and being associated with a more careerist attitude to work (the career effect). At the same time, they feel comfortable working with women (the zone of comfort effect). Despite this comfort, men adopt a variety of strategies to re-establish a masculinity that has been undermined by the 'feminine' nature of their work. These include re-labeling, status enhancement and distancing from the feminine. The dynamics of maintaining and reproducing masculinities within the non-traditional work setting are discussed in the light of recent theorising around gender, masculinity and work

Imager Evaluation of Diabetic Retinopathy at the Time of Imaging in a Telemedicine Program

Objective: To evaluate the ability of certified retinal imagers to identify presence versus absence of sight-threatening diabetic retinopathy (stDR) (moderate nonproliferative diabetic retinopathy or worse or diabetic macular edema) at the time of retinal imaging in a telemedicine program. Research Design and Methods: Diabetic patients in a primary care setting or specialty diabetes clinic received Joslin Vision Network protocol retinal imaging as part of their care. Trained nonphysician imagers graded the presence versus absence of stDR at the time of imaging. These gradings were compared with masked gradings of certified readers. Results: Of 158 patients (316 eyes) imaged, all cases of stDR (42 eyes [13%]) were identified by the imagers at the time of imaging. Six eyes with mild nonproliferative diabetic retinopathy were graded by the imagers to have stDR (sensitivity 1.00, 95% CI 0.90–1.00; specificity 0.97, 0.94–0.99). Conclusions: Appropriately trained imagers can accurately identify stDR at the time of imaging

The appropriation of hegemonic masculinity within selected research on men's health

Connell's hegemonic masculinity thesis (HMT) has occupied a relatively dominant position within contemporary research exploring the lives of men. Messerschmidt has conducted a review of recent literature that purports to use HMT, he describes in detail some of the ways Connell's work has been appropriated. Taking Messerschmidt's lead, this paper explores a small selection of men's health research that employ HMT as a central organising theme. Such a narrow focus and limited sample enables the theoretical, conceptual and empirical contributions of engagements with Connell's work to be critically explored in detail. This paper provides colleagues with clear examples of ways in which reified and reductive account of masculinity, are still being reproduced in contemporary analyses of men's lives. In calling for researchers to critically reflect upon their usage of Connell's thesis in more detail, my aim is to increase the subtlety and sophistication of such works. A further hope is that by highlighting specific examples of the need to appraise the relevance and adequacy of HMT as a conceptual frame of lived experiences, we might encourage researchers to access the multitude of different theoretical positions that speak to the lives of men

A pragmatic cognitive model for the interpretation of verbal–visual communication in television news programmes

The combination of the verbal and the visual track in television news discourse poses a considerable analytical challenge. In the viewers’ minds the co-habitation of these two semiotic channels triggers a complex network of inferential processes, based on expectations of coherence and relevance, with which they make sense of the representation of the world offered in the news. Through the analysis of a number of news items, this article considers the cognitive processes which viewers may activate when extracting meaning from the multimedial messages contained in television news. The analysis of news items from two British television networks offered by the authors traces the possible meanings that, it is assumed, become available to a potential, ‘idealised’ or ‘implied’ viewer, who accesses the information with some social and cultural knowledge of contemporary Britain. Building on existing studies, the article proposes a model for the classification of verbal–visual relations

A qualitative study on the effects of psychoactive substance use upon artistic creativity

Background: Psychoactive substance use has often been claimed to help generate and facilitate the artistic creative process. Aims: The present study explored the role of artists’ substance use in their creative processes and their efforts to balance between enhancement and relaxation. Methods: Semi-structured interviews concerning the artistic creative process and the role of psychoactive substance use were recorded with 72 artists and analyzed using content analysis. The participants were classified according to their substance use in three groups (Cannabis Group, Alcohol Group, and Control Group). Results: Results show that both alcohol and cannabis were used to facilitate creativity and the emotional states that are necessary for the artistic creative process. Participants in the Control group reported that listening to music might function as a mind-altering tool. It was also found that for some artists, substance use is not only characteristic to creation, but it is also part of their everyday lives. Conclusion: Artists are aware of the balancing phenomenon during the artistic creative process. Whether psychoactive substance(s) or other environmental stimuli (such as music) are used to reach the required effect appears to depend upon the individual

'What was your blood sugar reading this morning?': representing diabetes self-management on Facebook

Social networking sites have swiftly become a salient venue for the production and consumption of neoliberal health discourse by individuals and organisations. These platforms offer both opportunities for individuals to accrue coping resources and a means for organisations to promote their agendas to an online audience. Focusing specifically on diabetes, this article examines the representation of social actors and interactional styles on three organisational Pages on Facebook. Drawing on media and communication theories, we situate this linguistic analysis in relation to the communicative affordances employed by these organisations as they publish content online. Diabetes sufferers are represented as an at-risk group whose vulnerabilities can be managed through forms of participation specific to the respective organisation. More popular diabetes Pages draw on the opportunities for social interaction afforded by Facebook and combine informational and promotional content to foster communication between the organisation and its audience. By encouraging reflexive management of diabetes risks, these Pages contribute to the construction of ‘biological citizens’ who interweave habitual interactions on social networking sites with responsible self-care, consumption of health information and health activism

Informational entropy : a failure tolerance and reliability surrogate for water distribution networks

Evolutionary algorithms are used widely in optimization studies on water distribution networks. The optimization algorithms use simulation models that analyse the networks under various operating conditions. The solution process typically involves cost minimization along with reliability constraints that ensure reasonably satisfactory performance under abnormal operating conditions also. Flow entropy has been employed previously as a surrogate reliability measure. While a body of work exists for a single operating condition under steady state conditions, the effectiveness of flow entropy for systems with multiple operating conditions has received very little attention. This paper describes a multi-objective genetic algorithm that maximizes the flow entropy under multiple operating conditions for any given network. The new methodology proposed is consistent with the maximum entropy formalism that requires active consideration of all the relevant information. Furthermore, an alternative but equivalent flow entropy model that emphasizes the relative uniformity of the nodal demands is described. The flow entropy of water distribution networks under multiple operating conditions is discussed with reference to the joint entropy of multiple probability spaces, which provides the theoretical foundation for the optimization methodology proposed. Besides the rationale, results are included that show that the most robust or failure-tolerant solutions are achieved by maximizing the sum of the entropies