260 research outputs found

    CupMar: A deep learning model for personalized news recommendation based on contextual user-profile and multi-aspect article representation

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    OnlinePublIn modern days, making recommendation for news articles poses a great challenge due to vast amount of online information. However, providing personalized recommendations from news articles, which are the sources of condense textual information is not a trivial task. A recommendation system needs to understand both the textual information of a news article, and the user contexts in terms of long-term and temporary preferences via the user’s historic records. Unfortunately, many existing methods do not possess the capability to meet such need. In this work, we propose a neural deep news recommendation model called CupMar, that not only is able to learn the user-profile representation in different contexts, but also is able to leverage the multi-aspects properties of a news article to provide accurate, personalized news recommendations to users. The main components of our CupMar approach include the News Encoder and the User-Profile Encoder. Specifically, the News Encoder uses multiple properties such as news category, knowledge entity, title and body content with advanced neural network layers to derive informative news representation, while the User-Profile Encoder looks through a user’s browsed news, infers both of her long-term and recent preference contexts to encode a user representation, and finds the most relevant candidate news for her. We evaluate our CupMar model with extensive experiments on the popular Microsoft News Dataset (MIND), and demonstrate the strong performance of our approach.Dai Hoang Tran, Quan Z. Sheng, Wei Emma Zhang, Nguyen H. Tran, Nguyen Lu Dang Kho

    Thermo-hydro-mechanical responses of the host rock in the context of geological nuclear waste disposal

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    Deep geological disposal facility has been considered as the most appropriated solution for the safe longterm management of high-level radioactive waste (HLW). Geologic disposal solution consists of isolating the radioactive waste from the biosphere. Argillaceous rock has been selected in several countries as host formation due to its favorable properties to isolate radionuclides and chemical contaminants (very low permeability, stable, high retention capacity, self-sealing, etc). Clays in their natural state is usually saturated. Disposal of the exothermic waste packages in the repository leads to an increase in temperature within the host rock, which induces the pore pressure build-up due to the difference in thermal expansion coefficients of the pore water and the solid skeleton. The excess pore pressure generally leads to a decrease in the effective stress and can provoke thermally hydraulic fracturing or shear failure. Therefore, understanding the thermo-hydro-mechanical (THM) responses of the saturated host rock due to the heat generated form waste packages is a key issue to assess the feasibility of the repository. This paper aims at presenting coupled THM constitutive equations for a saturated porous medium and its finite element (FEM) discretization and solution. The solution is validated against analytical solution and other numerical results from a benchmark within an international project. FEM program is then used to describe the THM behavior of the host rock around a HLW repository (i.e. near field responses). Sensitivity analysis were performed to evaluate effect of material anisotropy and hydraulic condition on the micro-tunnel wall

    Dilatometry study of the ferromagnetic order in single-crystalline URhGe

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    Thermal expansion measurements have been carried out on single-crystalline URhGe in the temperature range from 2 to 200 K. At the ferromagnetic transition (Curie temperature T_C = 9.7 K), the coefficients of linear thermal expansion along the three principal orthorhombic axes all exhibit pronounced positive peaks. This implies that the uniaxial pressure dependencies of the Curie temperature, determined by the Ehrenfest relation, are all positive. Consequently, the calculated hydrostatic pressure dependence dT_C/dp is positive and amounts to 0.12 K/kbar. In addition, the effective Gruneisen parameter was determined. The low-temperature electronic Gruneisen parameter \Gamma_{sf} = 14 indicates an enhanced volume dependence of the ferromagnetic spin fluctuations at low temperatures. Moreover, the volume dependencies of the energy scales for ferromagnetic order and ferromagnetic spin fluctuations were found to be identical.Comment: 5 page

    Evidence for a ferromagnetic quantum critical point in URhGe doped with Ru

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    We have investigated the evolution of ferromagnetic order in the correlated metal series URh_{1-x}Ru_{x}Ge. Magnetization, transport and specific heat measurements provide convincing evidence for a ferromagnetic quantum critical point at the critical concentration x_{c} = 0.38. Here we report ac-susceptibility and magnetization measurements on selected samples with Ru doping concentrations near the critical point.Comment: 2 pages, conference paper, submitted to the proceedings of SCES'0

    Fresnel laws at curved dielectric interfaces of microresonators

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    We discuss curvature corrections to Fresnel's laws for the reflection and transmission of light at a non-planar refractive-index boundary. The reflection coefficients are obtained from the resonances of a dielectric disk within a sequential-reflection model. The Goos-H\"anchen effect for curved light fronts at a planar interface can be adapted to provide a qualitative and quantitative extension of the ray model which explains the observed deviations from Fresnel's laws.Comment: submitted to Phys. Rev.

    Size-dependent decoherence of excitonic states in semiconductor microcrystallites

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    The size-dependent decoherence of the exciton states resulting from the spontaneous emission is investigated in a semiconductor spherical microcrystallite under condition aB≪R0≤λa_{B}\ll R_{0}\leq\lambda. In general, the larger size of the microcrystallite corresponds to the shorter coherence time. If the initial state is a superposition of two different excitonic coherent states, the coherence time depends on both the overlap of two excitonic coherent states and the size of the microcrystallite. When the system with fixed size is initially in the even or odd coherent states, the larger average number of the excitons corresponds to the faster decoherence. When the average number of the excitons is given, the bigger size of the microcrystallite corresponds to the faster decoherence. The decoherence of the exciton states for the materials GaAs and CdS is numerically studied by our theoretical analysis.Comment: 4 pages, two figure

    Hexagonal dielectric resonators and microcrystal lasers

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    We study long-lived resonances (lowest-loss modes) in hexagonally shaped dielectric resonators in order to gain insight into the physics of a class of microcrystal lasers. Numerical results on resonance positions and lifetimes, near-field intensity patterns, far-field emission patterns, and effects of rounding of corners are presented. Most features are explained by a semiclassical approximation based on pseudointegrable ray dynamics and boundary waves. The semiclassical model is also relevant for other microlasers of polygonal geometry.Comment: 12 pages, 17 figures (3 with reduced quality

    Delivering the world’s most intense muon beam

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    A new muon beam line, the muon science innovative channel, was set up at the Research Center for Nuclear Physics, Osaka University, in Osaka, Japan, using the 392 MeV proton beam impinging on a target. The production of an intense muon beam relies on the efficient capture of pions, which subsequently decay to muons, using a novel superconducting solenoid magnet system. After the pion-capture solenoid, the first 36° of the curved muon transport line was commissioned and the muon flux was measured. In order to detect muons, a target of either copper or magnesium was placed to stop muons at the end of the muon beam line. Two stations of plastic scintillators located upstream and downstream from the muon target were used to reconstruct the decay spectrum of muons. In a complementary method to detect negatively charged muons, the x-ray spectrum yielded by muonic atoms in the target was measured in a germanium detector. Measurements, at a proton beam current of 6 pA, yielded (10.4±2.7)×10^{5}  muons per watt of proton beam power (μ^{+} and μ^{-}), far in excess of other facilities. At full beam power (400 W), this implies a rate of muons of (4.2±1.1)×10^{8}  muons s^{−1}, among the highest in the world. The number of μ^{-} measured was about a factor of 10 lower, again by far the most efficient muon beam produced. The setup is a prototype for future experiments requiring a high-intensity muon beam, such as a muon collider or neutrino factory, or the search for rare muon decays which would be a signature for phenomena beyond the Standard Model of particle physics. Such a muon beam can also be used in other branches of physics, nuclear and condensed matter, as well as other areas of scientific research

    Anti-biofouling implantable catheter using thin-film magnetic microactuators

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    Here we report on the development of polyimide-based flexible magnetic actuators for actively combating biofouling that occurs in many chronically implanted devices. The thin-film flexible devices are microfabricated and integrated into a single-pore silicone catheter to demonstrate a proof-of-concept for a self-clearing smart catheter. The static and dynamic mechanical responses of the thin-film magnetic microdevices were quantitatively measured and compared to theoretical values. The mechanical fatigue properties of these polyimide-based microdevices were also characterized up to 300 million cycles. Finally, the biofouling removal capabilities of magnetically powered microdevices were demonstrated using bovine serum albumin and bioconjugated microbeads. Our results indicate that these thin-film microdevices are capable of significantly reducing the amount of biofouling. At the same time, we demonstrated that these microdevices are mechanically robust enough to withstand a large number of actuation cycles during its chronic implantation
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