4,643 research outputs found

    Inducing Language Networks from Continuous Space Word Representations

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    Recent advancements in unsupervised feature learning have developed powerful latent representations of words. However, it is still not clear what makes one representation better than another and how we can learn the ideal representation. Understanding the structure of latent spaces attained is key to any future advancement in unsupervised learning. In this work, we introduce a new view of continuous space word representations as language networks. We explore two techniques to create language networks from learned features by inducing them for two popular word representation methods and examining the properties of their resulting networks. We find that the induced networks differ from other methods of creating language networks, and that they contain meaningful community structure.Comment: 14 page

    L-H transition dynamics in fluid turbulence simulations with neoclassical force balance

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    Spontaneous transport barrier generation at the edge of a magnetically confined plasma is investigated. To this end, a model of electrostatic turbulence in three-dimensional geometry is extended to account for the impact of friction between trapped and passing particles on the radial electric field. Non-linear flux-driven simulations are carried out, and it is shown that considering the radial and temporal variations of the neoclassical friction coefficients allows for a transport barrier to be generated above a threshold of the input power

    Benchmark generator for CEC 2009 competition on dynamic optimization

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    Evolutionary algorithms(EAs) have been widely applied to solve stationary optimization problems. However, many real-world applications are actually dynamic. In order to study the performance of EAs in dynamic environments, one important task is to develop proper dynamic benchmark problems. Over the years, researchers have applied a number of dynamic test problems to compare the performance of EAs in dynamic environments, e.g., the “moving peaks ” benchmark (MPB) proposed by Branke [1], the DF1 generator introduced by Morrison and De Jong [6], the singleand multi-objective dynamic test problem generator by dynamically combining different objective functions of exiting stationary multi-objective benchmark problems suggested by Jin and Sendhoff [2], Yang and Yao’s exclusive-or (XOR) operator [10, 11, 12], Kang’s dynamic traveling salesman problem (DTSP) [3] and dynamic multi knapsack problem (DKP), etc. Though a number of DOP generators exist in the literature, there is no unified approach of constructing dynamic problems across the binary space, real space and combinatorial space so far. This report uses the generalized dynamic benchmark generator (GDBG) proposed in [4], which construct dynamic environments for all the three solution spaces. Especially, in the rea

    Quasilinear hyperbolic Fuchsian systems and AVTD behavior in T2-symmetric vacuum spacetimes

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    We set up the singular initial value problem for quasilinear hyperbolic Fuchsian systems of first order and establish an existence and uniqueness theory for this problem with smooth data and smooth coefficients (and with even lower regularity). We apply this theory in order to show the existence of smooth (generally not analytic) T2-symmetric solutions to the vacuum Einstein equations, which exhibit AVTD (asymptotically velocity term dominated) behavior in the neighborhood of their singularities and are polarized or half-polarized.Comment: 78 page

    Analysis of previous microscopic calculations for second 0+0^+ state in 12^{12}C in terms of 3-alpha particle Bose-condensed state

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    The wave function of the second 0+0^+ state of 12^{12}C which was obtained long time ago by solving the microscopic 3α\alpha problem is shown to be almost completely equivalent to the wave function of the 3α\alpha condensed state which has been proposed recently by the present authors. This equivalence of the wave functions is shown to hold in two cases where different effective two-nucleon forces are adopted. This finding gives strong support for interpreting the second 0+0^+ state of 12^{12}C which is the key state for the synthesis of 12^{12}C in stars ('Hoyle' state), and which is one of the typical mysterious 0+0^+ states in light nuclei, as a gas-like structure of three α\alpha particles, Bose-condensed into an identical s-wave function.Comment: revtex, 5 pages, 2 figures, submitted to Phys. Rev.

    Combining Static Analysis and Test Generation for {C} Program Debugging

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    International audienceSoftware validation remains crucial in software development process. Traditionally viewed as separate domains, static and dynamic analysis have complementary strengths and weaknesses and can be both applied to program validation and verification. This paper presents our ongoing work on a tool prototype called SANTE (Static ANalysis and TEsting), implementing a combination of static analysis and structural program tetsting for detection of run-time errors in C programs. First, a static analysis tool (Frama-C) is called to generate alarms when it cannot ensure the absence of run-time errors. Second, these alarms guide a structural test generation tool (PathCrawler) trying to confirm alarms by activating bugs on some test cases. Our experiments on real-life software show that this combination can outperform the use of each technique independently

    Alpha cluster condensation in 12C and 16O

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    A new α\alpha-cluster wave function is proposed which is of the α\alpha-particle condensate type. Applications to 12^{12}C and 16^{16}O show that states of low density close to the 3 resp. 4 α\alpha-particle threshold in both nuclei are possibly of this kind. It is conjectured that all self-conjugate 4nn nuclei may show similar features.Comment: 4 pages, 2 tables, 2 figure

    Role of Steroid Therapy after Ischemic Stroke by N-Methyl-D-Aspartate Receptor Gene Regulation

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    Background: Stroke is the main cause of cerebrovascular disease mortality. Prolonged stimulation of N-methyl-D-aspartate (NMDA) receptor subtypes by the accumulation of glutamate neurotransmitter in the extracellular space after a stroke could activate cell death pathways. It is reported that progesterone provides different mechanisms of neuroprotection and could be considered as a candidate for stroke treatment. This study aimed to investigate progesterone impact on the expression of NMDA receptor subunits NR1, NR2(A and B), NR3 (A and B) after an experimental model of ischemic stroke which is followed by an in silico analysis. Methods: Progesterone was introduced subcutaneously after transient middle cerebral artery occlusion in male rats. After a period of reperfusion, a set of behavioral tests was performed to evaluate the postischemic neurological deficits. The 2,3,5-triphenyltetrazolium chloride staining method was done for quantification of infarct volume and gene expression analysis was performed in the penumbra region using reverse transcription polymerase chain reaction for NMDA receptor subunits. An AutoDock tool was employed to perform molecular docking analyses for evaluation of progesterone interaction with NMDA receptor. Results: Cerebral ischemia caused a significant downregulation in NR1, NR2A, NR2B and a profound upregulation of NR3B in cortical penumbraregion. Treatment with progesterone resu lted in upregulation of NR1, NR2A, and NR3B which could explain a possible the neuroprotection of steroids via binding to NMDA glutamate receptor. In addition, in silico analysis revealed that progesterone could strongly interact with NR1/NR2B and NR2A. Conclusion: The findings elucidate a new aspect of the neuroprotective mechanism of progesterone via NMDA receptors gene regulation. Keywords: Stroke NMDA receptor Progesterone Gene expressio

    Weak Values with Decoherence

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    The weak value of an observable is experimentally accessible by weak measurements as theoretically analyzed by Aharonov et al. and recently experimentally demonstrated. We introduce a weak operator associated with the weak values and give a general framework of quantum operations to the W operator in parallel with the Kraus representation of the completely positive map for the density operator. The decoherence effect is also investigated in terms of the weak measurement by a shift of a probe wave function of continuous variable. As an application, we demonstrate how the geometric phase is affected by the bit flip noise.Comment: 17 pages, 3 figure

    R-mode Instability of Slowly Rotating Non-isentropic Relativistic Stars

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    We investigate properties of rr-mode instability in slowly rotating relativistic polytropes. Inside the star slow rotation and low frequency formalism that was mainly developed by Kojima is employed to study axial oscillations restored by Coriolis force. At the stellar surface, in order to take account of gravitational radiation reaction effect, we use a near-zone boundary condition instead of the usually imposed boundary condition for asymptotically flat spacetime. Due to the boundary condition, complex frequencies whose imaginary part represents secular instability are obtained for discrete rr-mode oscillations in some polytropic models. It is found that such discrete rr-mode solutions can be obtained only for some restricted polytropic models. Basic properties of the solutions are similar to those obtained by imposing the boundary condition for asymptotically flat spacetime. Our results suggest that existence of a continuous part of spectrum cannot be avoided even when its frequency becomes complex due to the emission of gravitational radiation.Comment: 10 pages, 4 figures, accepted for publlication in PR
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