6,018 research outputs found

    Analytical study of hydrogen turbopump cycles for advanced nuclear rockets Progress report, Sep. 15, 1964 - Sep. 15, 1965

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    Hydrogen turbopump cycles for obtaining high engine inlet pressures in advanced nuclear rockets, and data on gaseous nuclear reactors and heavy gas containmen

    Parametric Fokker-Planck equation

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    We derive the Fokker-Planck equation on the parametric space. It is the Wasserstein gradient flow of relative entropy on the statistical manifold. We pull back the PDE to a finite dimensional ODE on parameter space. Some analytical example and numerical examples are presented

    Indication for π+π\pi^+ \pi^- scattering in p+pp+p collisions at sNN=\sqrt{s_{_{NN}}} = 200 GeV

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    A ρ(770)0\rho(770)^0 mass shift of about -40 MeV/c2c^2 was measured in p+pp+p collisions at sNN=\sqrt{s_{_{NN}}} = 200 GeV at RHIC. Previous mass shifts have been observed at CERN-LEBC-EHS and CERN-LEP. We will show that phase space does not account for the ρ(770)0\rho(770)^0 mass shift measured at RHIC, CERN-LEBC-EHS and CERN-LEP and conclude that there are significant scattering interactions in p+pp+p collisions.Comment: 11 pages and 7 figure

    Barriers and facilitators to HIV and syphilis rapid diagnostic testing in antenatal care settings in low-income and middle-income countries: A systematic review

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    Background Testing and treatment during pregnancy is a well-established and cost-effective prevention strategy, which relies largely on use of rapid diagnostic tests (RDTs). Yet, in many low-income and-middle-income countries, the uptake of RDTs is suboptimal. A qualitative meta-synthesis was conducted to identify the barriers and enablers to use of HIV and syphilis RDTs among pregnant women in low-income and middle-income countries. Methods This review was conducted using PRISMA guidelines. Eligible studies included peer-reviewed publications, which used qualitative methods to explore HIV and syphilis RDT in antenatal care clinics in low-income and middle-income countries. Studies focusing on perspectives of pregnant women, healthcare workers and/or stakeholders were included. We used an inductive approach informed by a modified socioecological model to synthesise the data. Results 62 manuscripts met the eligibility criteria. For pregnant women, initial acceptance of the RDT and continuation in antenatal care depends on the perception that engaging in testing will be a beneficial experience for their baby and themselves, often influenced by the provision of services that are gender-sensitive, confidential, respectful, flexible and considers their well-being into the future. Local sociocultural beliefs about pregnancy and diseases, awareness of diseases and gender roles in society also influenced RDT acceptability among pregnant women. For healthcare workers, the ability to provide high-quality RDT care required ongoing training, accurate and easy to use tests, support from supervisors and communities, sufficient resources and staffing to provide services, and reliable salary. At the stakeholder level, well-developed guidelines and health system infrastructures were imperative to the delivery of RDT in antenatal clinics. Conclusion Our findings highlight clear gaps to the provision of sustainable and culturally acceptable maternal HIV and/or syphilis screening using RDTs. In addition, greater attention needs to be paid to community stakeholders in promoting the uptake of RDT in antenatal clinics. PROSPERO registration number CRD42018112190

    "How May I Help You?": Modeling Twitter Customer Service Conversations Using Fine-Grained Dialogue Acts

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    Given the increasing popularity of customer service dialogue on Twitter, analysis of conversation data is essential to understand trends in customer and agent behavior for the purpose of automating customer service interactions. In this work, we develop a novel taxonomy of fine-grained "dialogue acts" frequently observed in customer service, showcasing acts that are more suited to the domain than the more generic existing taxonomies. Using a sequential SVM-HMM model, we model conversation flow, predicting the dialogue act of a given turn in real-time. We characterize differences between customer and agent behavior in Twitter customer service conversations, and investigate the effect of testing our system on different customer service industries. Finally, we use a data-driven approach to predict important conversation outcomes: customer satisfaction, customer frustration, and overall problem resolution. We show that the type and location of certain dialogue acts in a conversation have a significant effect on the probability of desirable and undesirable outcomes, and present actionable rules based on our findings. The patterns and rules we derive can be used as guidelines for outcome-driven automated customer service platforms.Comment: 13 pages, 6 figures, IUI 201

    ρ(770)0\rho(770)^0, K(892)0^*(892)^0 and f0(980)_{0}(980) Production in Au-Au and pp Collisions at sNN\sqrt{s_{NN}} = 200 GeV

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    Preliminary results on ρ(770)0π+π\rho(770)^0 \to \pi^{+}\pi^{-}, K(892)0π^{*}(892)^{0} \to \piK and f0(980)π+πf_{0}(980) \to \pi^{+}\pi^{-} production using the mixed-event technique are presented. The measurements are performed at mid-rapidity by the STAR detector in sNN\sqrt{s_{NN}}= 200 GeV Au-Au and pp interactions at RHIC. The results are compared to different measurements at various energies.Comment: 4 pages, 6 figures. Talk presented at Quark Matter 2002, Nantes, France, July 18-24, 2002. To appear in the proceedings (Nucl. Phys. A

    Replica theory for learning curves for Gaussian processes on random graphs

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    Statistical physics approaches can be used to derive accurate predictions for the performance of inference methods learning from potentially noisy data, as quantified by the learning curve defined as the average error versus number of training examples. We analyse a challenging problem in the area of non-parametric inference where an effectively infinite number of parameters has to be learned, specifically Gaussian process regression. When the inputs are vertices on a random graph and the outputs noisy function values, we show that replica techniques can be used to obtain exact performance predictions in the limit of large graphs. The covariance of the Gaussian process prior is defined by a random walk kernel, the discrete analogue of squared exponential kernels on continuous spaces. Conventionally this kernel is normalised only globally, so that the prior variance can differ between vertices; as a more principled alternative we consider local normalisation, where the prior variance is uniform

    Monte Carlo simulation of virtual Compton scattering below pion threshold

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    This paper describes the Monte Carlo simulation developed specifically for the VCS experiments below pion threshold that have been performed at MAMI and JLab. This simulation generates events according to the (Bethe-Heitler + Born) cross section behaviour and takes into account all relevant resolution-deteriorating effects. It determines the `effective' solid angle for the various experimental settings which are used for the precise determination of photon electroproduction absolute cross section.Comment: 24 pages, 6 figures, to be published in Nuclear Instruments and Methods in Physics Research, A One author adde

    Molecular structures of gas‐phase polyatomic molecules determined by spectroscopic methods

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    Spectroscopic data related to the structures of polyatomic molecules in the gas phase have been reviewed, critically evaluated, and compiled. All reported bond distances and angles have been classified as equilibrium (re), average (rz), substitution (rs), or effective (ro) parameters, and have been given a quality rating which is a measure of the parameter uncertainty. The surveyed literature includes work from all of the areas of gas‐phase spectroscopy from which precise quantitative structural information can be derived. Introductory material includes definitions of the various types of parameters and a description of the evaluation procedure.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87746/2/619_1.pd

    Resonance Production

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    Recent results on rho(770)^0, K(892)^*0, f_0(980), phi(1020), Delta(1232)^++, and Lambda(1520) production in A+A and p+p collisions at SPS and RHIC energies are presented. These resonances are measured via their hadronic decay channels and used as a sensitive tool to examine the collision dynamics in the hadronic medium through their decay and regeneration. The modification of resonance mass, width, and shape due to phase space and dynamical effects are discussed.Comment: 8 pages, 10 figures, proceedings of the Quark Matter 2004, in Oakland, California, to be published in Journal of Physics G: Nuclear and Particle Physic
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