4,561 research outputs found

    Titanium honeycomb structure

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    A brazed titanium honeycomb sandwich system for supersonic transport wing cover panels provides the most efficient structure spanwise, chordwise, and loadwise. Flutter testing shows that high wing stiffness is most efficient in a sandwich structure. This structure also provides good thermal insulation if liquid fuel is carried in direct contact with the wing structure in integral fuel tanks

    Robust Face Recognition in Rotated Eigen Space

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    Face recognition is a very complex classification problem due to nuisance variations in different conditions. Most face recognition approaches either assume constant lighting condition or standard facial expressions, thus cannot deal with both kinds of variations simultaneously. Principal Component Analysis (PCA) cannot handle complex pattern variations such as illumination and expression. Adaptive PCA rotates eigenspace to extract more representative features thus improving the performance. In this paper, we present a way to extract various sets of features by different eigenspace rotations and propose a method to fuse these features to generate nonorthogonal mappings for face recognition. The proposed method is tested on the Asian Face Database with 856 images from 107 subjects with 5 lighting conditions and 4 expressions. We register only one normally lit neutral face image and test on the remaining face images with variations. Experiments show a 95% classification accuracy and a 20% reduction in error rate. This illustrates that the fused features can provide significantly improved pattern classification

    Vision Processing in Intelligent CCTV for Mass Transport Security

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    Intelligent Surveillance Systems is attracting unprecedented attention from research and industry. In this paper, we describe a real-life trial system where various video analytic systems are used to detect events and objects of interests in a mass transport environment. The system configuration and architecture of this system is presented. In addition to implementation and scalability challenges, we discuss issues related to on-going trials in public spaces incorporating existing surveillance hardware

    Australian residential aged care home staff experiences of implementing an intervention to improve palliative and end-of-life care for residents: A qualitative study

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    Access to high-quality and safe evidence-based palliative care (PC) is important to ensure good end-of-life care for older people in residential aged care homes (RACHs). However, many barriers to providing PC in RACHs are frequently cited. The Quality End-of-Life Care (QEoLC) Project was a multicomponent intervention that included training, evidence-based tools and tele-mentoring, aiming to equip healthcare professionals and careworkers in RACHs with knowledge, skills and confidence in providing PC to residents. This study aims to understand: (1) the experiences of healthcare professionals, careworkers, care managers, planners/implementers who participated in the implementation of the QEoLC Project; and (2) the barriers and facilitators to the implementation. Staff from two RACHs in New South Wales, Australia were recruited between September to November 2021. Semi-structured interviews and thematic data analysis were used. Fifteen participants (seven health professionals [includes one nurse, two clinical educators, three workplace trainers, one clinical manager/nurse], three careworkers and five managers) were interviewed. Most RACH participants agreed that the QEoLC Project increased their awareness of PC and provided them with the skills/confidence to openly discuss death and dying. Participants perceived that the components of the QEoLC Project had the following benefits for residents: more appropriate use of medications, initiation of timely pain management and discussions with families regarding end-of-life care preferences. Key facilitators for implementation were the role of champions, the role of the steering committee, regular clinical meetings to discuss at-risk residents and mentoring. Implementation barriers included: high staff turnover, COVID-19 pandemic, time constraints, perceived absence of executive sponsorship, lack of practical support and systems-related barriers. The findings underline the need for strong leadership, supportive organisational culture and commitment to the implementation of processes for improving the quality of end-of-life care. Furthermore, the results highlight the need for codesigning the intervention with RACHs, provision of dedicated staff/resources to support implementation, and integration of project tools with existing systems for achieving effective implementation outcomes

    Corticosterone Regulates Both Naturally Occurring and Cocaine‐Induced Dopamine Signaling by Selectively Decreasing Dopamine Uptake

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    Stressful and aversive events promote maladaptive reward‐seeking behaviors such as drug addiction by acting, in part, on the mesolimbic dopamine system. Using animal models, data from our laboratory and others show that stress and cocaine can interact to produce a synergistic effect on reward circuitry. This effect is also observed when the stress hormone corticosterone is administered directly into the nucleus accumbens (NAc), indicating that glucocorticoids act locally in dopamine terminal regions to enhance cocaine\u27s effects on dopamine signaling. However, prior studies in behaving animals have not provided mechanistic insight. Using fast‐scan cyclic voltammetry, we examined the effect of systemic corticosterone on spontaneous dopamine release events (transients) in the NAc core and shell in behaving rats. A physiologically relevant systemic injection of corticosterone (2 mg/kg i.p.) induced an increase in dopamine transient amplitude and duration (both voltammetric measures sensitive to decreases in dopamine clearance), but had no effect on the frequency of transient release events. This effect was compounded by cocaine (2.5 mg/kg i.p.). However, a second experiment indicated that the same injection of corticosterone had no detectable effect on the dopaminergic encoding of a palatable natural reward (saccharin). Taken together, these results suggest that corticosterone interferes with naturally occurring dopamine uptake locally, and this effect is a critical determinant of dopamine concentration specifically in situations in which the dopamine transporter is pharmacologically blocked by cocaine

    Bayesian averaging for ground state masses of atomic nuclei in a Machine Learning approach

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    We present global predictions of the ground state mass of atomic nuclei based on a novel Machine Learning (ML) algorithm. We combine precision nuclear experimental measurements together with theoretical predictions of unmeasured nuclei. This hybrid data set is used to train a probabilistic neural network. In addition to training on this data, a physics-based loss function is employed to help refine the solutions. The resultant Bayesian averaged predictions have excellent performance compared to the testing set and come with well-quantified uncertainties which are critical for contemporary scientific applications. We assess extrapolations of the model's predictions and estimate the growth of uncertainties in the region far from measurements.Comment: 15 pages, 10 figures, comments welcom

    Neural activity of retinal ganglion cells under continuous, dynamically-modulated high frequency electrical stimulation

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    Objective. Current retinal prosthetics are limited in their ability to precisely control firing patterns of functionally distinct retinal ganglion cell (RGC) types. The aim of this study was to characterise RGC responses to continuous, kilohertz-frequency-varying stimulation to assess its utility in controlling RGC activity. Approach. We used in vitro patch-clamp experiments to assess electrically-evoked ON and OFF RGC responses to frequency-varying pulse train sequences. In each sequence, the stimulation amplitude was kept constant while the stimulation frequency (0.5-10 kHz) was changed every 40 ms, in either a linearly increasing, linearly decreasing or randomised manner. The stimulation amplitude across sequences was increased from 10 to 300 µA. Main results. We found that continuous stimulation without rest periods caused complex and irreproducible stimulus-response relationships, primarily due to strong stimulus-induced response adaptation and influence of the preceding stimulus frequency on the response to a subsequent stimulus. In addition, ON and OFF populations showed different sensitivities to continuous, frequency-varying pulse trains, with OFF cells generally exhibiting more dependency on frequency changes within a sequence. Finally, the ability to maintain spiking behaviour to continuous stimulation in RGCs significantly reduced over longer stimulation durations irrespective of the frequency order. Significance. This study represents an important step in advancing and understanding the utility of continuous frequency modulation in controlling functionally distinct RGCs. Our results indicate that continuous, kHz-frequency-varying stimulation sequences provide very limited control of RGC firing patterns due to inter-dependency between adjacent frequencies and generally, different RGC types do not display different frequency preferences under such stimulation conditions. For future stimulation strategies using kHz frequencies, careful consideration must be given to design appropriate pauses in stimulation, stimulation frequency order and the length of continuous stimulation duration

    LBADR: The LBA Data Recorder

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    The LBA (Long-Baseline Array) is an ad-hoc network of radio telescopes within Australia and is the only VLBI array in the Southern Hemisphere. Since 2004 all experiments have been recorded using standard computer hard-disks, replacing the aging tape based S2 system. The recorder developed for this, the LBADR, comprises largely of commercial off-the-shelf components and is closeley related to the PC-EVN syste

    The Micro-Arcsecond Scintillation-Induced Variability (MASIV) Survey II: The First Four Epochs

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    We report on the variability of 443 flat spectrum, compact radio sources monitored using the VLA for 3 days in 4 epochs at ~ 4 month intervals at 5 GHz as part of the Micro-Arcsecond Scintillation-Induced Variability (MASIV) survey. Over half of these sources exhibited 2-10% rms variations on timescales over 2 days. We analyzed the variations by two independent methods, and find that the rms variability amplitudes of the sources correlate with the emission measure in the ionized Interstellar Medium along their respective lines of sight. We thus link the variations with interstellar scintillation of components of these sources, with some (unknown) fraction of the total flux density contained within a compact region of angular diameter in the range 10-50 micro-arcseconds. We also find that the variations decrease for high mean flux density sources and, most importantly, for high redshift sources. The decrease in variability is probably due either to an increase in the apparent diameter of the source, or a decrease in the flux density of the compact fraction beyond z ~ 2. Here we present a statistical analysis of these results, and a future paper will the discuss the cosmological implications in detail.Comment: 62 pages, 13 figures. Accepted for publication in the Astrophysical Journa

    Dallas with balls: televized sport, soap opera and male and female pleasures

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    Two of the most popular of television genres, soap opera and sports coverage have been very much differentiated along gender lines in terms of their audiences. Soap opera has been regarded very much as a 'gynocentric' genre with a large female viewing audience while the audiences for television sport have been predominantly male. Gender differentiation between the genres has had implications for the popular image of each. Soap opera has been perceived as inferior; as mere fantasy and escapism for women while television sports has been perceived as a legitimate, even edifying experience for men. In this article the authors challenge the view that soap opera and television sport are radically different and argue that they are, in fact, very similar in a number of significant ways. They suggest that both genres invoke similar structures of feeling and sensibility in their respective audiences and that television sport is a 'male soap opera'. They consider the ways in which the viewing context of each genre is related to domestic life and leisure, the ways in which the textual structure and conventions of each genre invoke emotional identification, and finally, the ways in which both genres re-affirm gender identities
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