15,250 research outputs found
Robustness issues in a data-driven spoken language understanding system
Robustness is a key requirement in spoken language understanding (SLU) systems. Human speech is often ungrammatical and ill-formed, and there will frequently be a mismatch between training and test data. This paper discusses robustness and adaptation issues in a statistically-based SLU system which is entirely data-driven. To test robustness, the system has been tested on data from the Air Travel Information Service (ATIS) domain which has been artificially corrupted with varying levels of additive noise. Although the speech recognition performance degraded steadily, the system did not fail catastrophically. Indeed, the rate at which the end-to-end performance of the complete system degraded was significantly slower than that of the actual recognition component. In a second set of experiments, the ability to rapidly adapt the core understanding component of the system to a different application within the same broad domain has been tested. Using only a small amount of training data, experiments have shown that a semantic parser based on the Hidden Vector State (HVS) model originally trained on the ATIS corpus can be straightforwardly adapted to the somewhat different DARPA Communicator task using standard adaptation algorithms. The paper concludes by suggesting that the results presented provide initial support to the claim that an SLU system which is statistically-based and trained entirely from data is intrinsically robust and can be readily adapted to new applications
Chronological conclusions from phonological and morphological data in the Aramaic of the book of Daniel
https://place.asburyseminary.edu/ecommonsatsdissertations/2015/thumbnail.jp
Theory and simulations of a gyrotron backward wave oscillator using a helical interaction waveguide
A gyrotron backward wave oscillator (gyro-BWO) with a helically corrugated interaction waveguide demonstrated its potential as a powerful microwave source with high efficiency and a wide frequency tuning range. This letter presents the theory describing the dispersion properties of such a waveguide and the linear beam-wave interaction. Numerical simulation results using the PIC code MAGIC were found to be in excellent agreement with the output measured from a gyro-BWO experiment
Modified Fowler-Nordheim Field-Emission Formulae from a Nonplanar-Emitter Model
Field emission formulae, current-voltage characteristics and energy
distribution of emitted electrons, are derived analytically for a nonplanar
(hyperboloidal) metallic emitter model. The traditional Fowler-Nordheim
formulae, which are derived from a planar emitter model, are modified, and the
assumption of the planar emitter in the F-N model is reconsidered. Our
analytical calculation also reveals the backgrounds of the previous numerical
discussion by He et al. on the effect of the geometry of emitter on field
emission. The new formulae contain a parameter which characterizes the
sharpness of the hyperboloidal emitter, and experimental data of field
emissions from clean tungsten emitters and nanotip emitters are analyzed by
making use of this feature.Comment: 9 pages, 8 figure
All the colours of the rainbow.
Our perception of colour has always been a source of fascination, so it's little wonder that studies of the phenomenon date back hundreds of years. What, though, can modern scientists learn from medieval literature — and how do we go about it
Classically integrable boundary conditions for symmetric-space sigma models
We investigate boundary conditions for the nonlinear sigma model on the
compact symmetric space , where is the subgroup fixed by an
involution of . The Poisson brackets and the classical local
conserved charges necessary for integrability are preserved by boundary
conditions in correspondence with involutions which commute with .
Applied to , the nonlinear sigma model on , these yield the
great circles as boundary submanifolds. Applied to , they
reproduce known results for the principal chiral model.Comment: 8 pages. v2 has an introduction added and a few minor correction
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