1,195 research outputs found

    Deep learning based classification of sheep behaviour from accelerometer data with imbalance

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    Classification of sheep behaviour from a sequence of tri-axial accelerometer data has the potential to enhance sheep management. Sheep behaviour is inherently imbalanced (e.g., more ruminating than walking) resulting in underperforming classification for the minority activities which hold importance. Existing works have not addressed class imbalance and use traditional machine learning techniques, e.g., Random Forest (RF). We investigated Deep Learning (DL) models, namely, Long Short Term Memory (LSTM) and Bidirectional LSTM (BLSTM), appropriate for sequential data, from imbalanced data. Two data sets were collected in normal grazing conditions using jaw-mounted and ear-mounted sensors. Novel to this study, alongside typical single classes, e.g., walking, depending on the behaviours, data samples were labelled with compound classes, e.g., walking_grazing. The number of steps a sheep performed in the observed 10 s time window was also recorded and incorporated in the models. We designed several multi-class classification studies with imbalance being addressed using synthetic data. DL models achieved superior performance to traditional ML models, especially with augmented data (e.g., 4-Class + Steps: LSTM 88.0%, RF 82.5%). DL methods showed superior generalisability on unseen sheep (i.e., F1-score: BLSTM 0.84, LSTM 0.83, RF 0.65). LSTM, BLSTM and RF achieved sub-millisecond average inference time, making them suitable for real-time applications. The results demonstrate the effectiveness of DL models for sheep behaviour classification in grazing conditions. The results also demonstrate the DL techniques can generalise across different sheep. The study presents a strong foundation of the development of such models for real-time animal monitoring

    Effect of continuum couplings in fusion of halo 11^{11}Be on 208^{208}Pb around the Coulomb barrier

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    The effect of continuum couplings in the fusion of the halo nucleus 11^{11}Be on 208^{208}Pb around the Coulomb barrier is studied using a three-body model within a coupled discretised continuum channels (CDCC) formalism. We investigate in particular the role of continuum-continuum couplings. These are found to hinder total, complete and incomplete fusion processes. Couplings to the projectile 1p1/21p_{1/2} bound excited state redistribute the complete and incomplete fusion cross sections, but the total fusion cross section remains nearly constant. Results show that continuum-continuum couplings enhance the irreversibility of breakup and reduce the flux that penetrates the Coulomb barrier. Converged total fusion cross sections agree with the experimental ones for energies around the Coulomb barrier, but underestimate those for energies well above the Coulomb barrier.Comment: 15 pages, 7 figures, accepted in Phys. Rev.

    The Ties that Double Bind Us: Career, Emotion and Narrative Coping in Difficult Working Relationships

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    This article examines through an autoethnographic account how career aspirations and constraints may lead individuals to endure emotionally aversive situations. It presents evidence that individuals in such situations engage in emotion‐focused coping through narrative, illustrated by the author’s autoethnographic narrative of a difficult working relationship which developed into a double bind situation. The paper suggests that narrative coping in response to a double bind can actually serve to reify and prolong such situations. The paper concludes that autoethnographic research does not lend itself to simple organisational solutions. Possible avenues for further research are outlined and discussed

    Elastic scattering and breakup of 17^F at 10 MeV/nucleon

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    Angular distributions of fluorine and oxygen produced from 170 MeV 17^F incident on 208^Pb were measured. The elastic scattering data are in good agreement with optical model calculations using a double-folding potential and parameters similar to those obtained from 16^O+208^Pb. A large yield of oxygen was observed near \theta_lab=36 deg. It is reproduced fairly well by a calculation of the (17^F,16^O) breakup, which is dominated by one-proton stripping reactions. The discrepancy between our previous coincidence measurement and theoretical predictions was resolved by including core absorption in the present calculation.Comment: 9 pages, 5 figure

    Very high precision bound state spectroscopy near a 85^{85}Rb Feshbach resonance

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    We precisely measured the binding energy of a molecular state near the Feshbach resonance in a 85^{85}Rb Bose-Einstein condensate (BEC). Rapid magnetic field pulses induced coherent atom-molecule oscillations in the BEC. We measured the oscillation frequency as a function of B-field and fit the data to a coupled-channels model. Our analysis constrained the Feshbach resonance position [155.041(18) G], width [10.71(2) G], and background scattering length [-443(3) a0_0] and yielded new values for vDSv_{DS}, vDTv_{DT}, and C6C_6. These results improved our estimate for the stability condition of an attractive BEC. We also found evidence for a mean-field shift to the binding energy.Comment: 5 pages, 2 figures, submitted to PR

    Pore-scale Modeling of Viscous Flow and Induced Forces in Dense Sphere Packings

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    We propose a method for effectively upscaling incompressible viscous flow in large random polydispersed sphere packings: the emphasis of this method is on the determination of the forces applied on the solid particles by the fluid. Pore bodies and their connections are defined locally through a regular Delaunay triangulation of the packings. Viscous flow equations are upscaled at the pore level, and approximated with a finite volume numerical scheme. We compare numerical simulations of the proposed method to detailed finite element (FEM) simulations of the Stokes equations for assemblies of 8 to 200 spheres. A good agreement is found both in terms of forces exerted on the solid particles and effective permeability coefficients

    Decision making and risk management in adventure sports coaching

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    Adventure sport coaches practice in environments that are dynamic and high in risk, both perceived and actual. The inherent risks associated with these activities, individuals’ responses and the optimal exploitation of both combine to make the processes of risk management more complex and hazardous than the traditional sports where risk management is focused almost exclusively on minimization. Pivotal to this process is the adventure sports coaches’ ability to make effective judgments regarding levels of risk, potential benefits and possible consequences. The exact nature of this decision making process should form the basis of coaching practice and coach education in this complex and dynamic field. This positional paper examines decision making by the adventure sports coach in these complex, challenging environments and seeks to stimulate debate whilst offering a basis for future research into this topic

    A Lyα Transit Left Undetected: The Environment and Atmospheric Behavior of K2-25b

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    K2-25b is a Neptune-sized exoplanet (3.45R ⊙) that orbits its M4.5 host with a period of 3.48 days. Due to its membership in the Hyades Cluster, the system has a known age (727 ± 75 Myr). K2-25b's youth and its similarities with Gl 436b suggested that K2-25b could be undergoing strong atmospheric escape. We observed two transits of K2-25b at Lyα using HST/STIS in order to search for escaping neutral hydrogen. We were unable to detect an exospheric signature, but placed an upper limit of (R p/R ⊙)|Ly α < 0.56 at 95% confidence by fitting the light curve of the Lyα red wing, or < 1.20 in the blue wing. We reconstructed the intrinsic Lyα profile of K2-25 to determine its Lyα flux, and analyzed XMM-Newton observations to determined its X-ray flux. Based on the total X-ray and extreme ultraviolet irradiation of the planet (8763 ± 1049 erg s-1 cm-2), we estimated the maximum energy-limited mass-loss rate of K2-25b to be 10.6-6.13+15.2}×1010 g s-1 (0.56M ⊙ per 1 Gyr), five times larger than the similarly estimated mass-loss rate of Gl 436b (2.2 ± 1010 g s-1). The photoionization time is about 3 hr, significantly shorter than Gl 436b's 14 hr. A nondetection of a Lyα transit could suggest K2-25b is not significantly losing its atmosphere, or factors of the system are resulting in the mass loss being unobservable (e.g., atmosphere composition or the system's large high-energy flux). Further observations could provide more stringent constraints

    Breakup of 17^{17}F on 208^{208}Pb near the Coulomb barrier

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    Angular distributions of oxygen produced in the breakup of 17^{17}F incident on a 208^{208}Pb target have been measured around the grazing angle at beam energies of 98 and 120 MeV. The data are dominated by the proton stripping mechanism and are well reproduced by dynamical calculations. The measured breakup cross section is approximately a factor of 3 less than that of fusion at 98 MeV. The influence of breakup on fusion is discussed.Comment: 7 pages, 8 figure

    Breast cancer treatment delays by socioeconomic and health care access latent classes in Black and White women

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    Background: Breast cancer mortality is higher for Black and younger women. This study evaluated 2 possible contributors to disparities—time to treatment and treatment duration—by race and age. Methods: Among 2841 participants with stage I-III disease in the Carolina Breast Cancer Study, we identified groups of women with similar patterns of socioeconomic status (SES), access to care, and tumor characteristics using latent class analysis. We then evaluated latent classes in association with treatment delay (initiation >60 days after diagnosis) and treatment duration (in quartiles by treatment modality). Results: Thirty-two percent of younger Black women were in the highest quartile of treatment duration (versus 22% of younger White women). Black women experienced a higher frequency of delayed treatment (adjusted relative frequency difference [RFD], 5.5% [95% CI, 3.2%-7.8%]) and prolonged treatment duration (RFD, 8.8% [95% CI, 5.7%-12.0%]). Low SES was significantly associated with treatment delay among White women (RFD, 3.5% [95% CI, 1.1%-5.9%]), but treatment delay was high at all levels of SES in Black women (eg, 11.7% in high SES Black women compared with 10.6% and 6.7% among low and high SES White women, respectively). Neither SES nor access to care classes were significantly associated with delayed initiation among Black women, but both low SES and more barriers were associated with treatment duration across both groups. Conclusions: Factors that influence treatment timeliness persist throughout the care continuum, with prolonged treatment duration being a sensitive indicator of differences by race, SES, and care barriers
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