There have been recent interest in meta-learning systems: i.e. networks that are trained to learn across multiple tasks. This paper focuses on optimization and generalization of a meta-learning system based on recurre...
There have been recent interest in meta-learning systems: i.e. networks that are trained to learn across multiple tasks. This paper focuses on optimization and generalization of a meta-learning system based on recurrent networks. The optimization investigates the influence of diverse structures and parameters on its performance. We demonstrate the generalization (robustness) of our meta-learning system to learn across multiple tasks including tasks unseen during the metatraining phase. We introduce a meta-cost function (Mean Squared Fair Error) that enhances the performance of the system by not penalizing it during transitions to learning a new task. Evaluation results are presented for Boolean and quadratic functions datasets. The best performance is obtained using a Long Short-Term Memory (LSTM) topology without a forget gate and with a clipped memory cell. The results demonstrate i) the impact of different LSTM architectures, parameters, and error functions on the meta-learning process;ii) that the mean squared fair error function does improve performance for best learning;and iii) the robustness of our meta-learning framework as it generalizes well when tested on tasks unseen during metatraining. Comparison between No-Forget-Gate LSTM and Gated Recurrent Unit also suggest that absence of a memory cell tends to degrade performance.
Ultrafast control of the magnetization in ps timescales by fs laser pulses offers an attractive avenue for applications such as fast magnetic devices for logic and memory. However, ultrafast helicity-independent all-o...
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Coherent light-matter interaction can be used to manipulate the energy levels of atoms, molecules and solids. When light with frequency ω is detuned away from a resonance ω 0 , repulsion between the photon-dressed (...
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Coherent light-matter interaction can be used to manipulate the energy levels of atoms, molecules and solids. When light with frequency ω is detuned away from a resonance ω 0 , repulsion between the photon-dressed (Floquet) states can lead to a shift of energy resonance. The dominant effect is the optical Stark shift (∝ 1/(ω 0 - ω)), but there is an additional contribution from the so-called Bloch-Siegert shift (∝ 1/(ω 0 + ω)). Although it is common in atoms and molecules, the observation of Bloch-Siegert shift in solids has so far been limited only to artificial atoms since the shifts were small (2 under infrared optical driving by virtue of the strong light-matter interaction in this system. Moreover, we can disentangle the Bloch-Siegert shift entirely from the optical Stark shift, because the two effects are found to obey opposite selection rules at different valleys. By controlling the light helicity, we can confine the Bloch-Siegert shift to occur only at one valley, and the optical Stark shift at the other valley. Such a valley-exclusive Bloch-Siegert shift allows for enhanced control over the valleytronic properties in two-dimensional materials, and offers a new avenue to explore quantum optics in solids.
Pseudomonas aeruginosa is an opportunistic, biofilm-forming pathogen. P. aeruginosa produces pyocyanin, a secondary metabolite as part of its quorum sensing signaling system activated during biofilm formation. Self-or...
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Objective: An effective training plan is an important factor in sports training to enhance athletic performance. A poorly considered training plan may result in injury to the athlete, and overtraining. Good training p...
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A ppb-level nitric oxide (NO) photoacoustic sensor was reported for outdoor environmental monitoring. The sensor employed a continuous wave (CW), distributed feedback (DFB), mid-infrared (mid-IR) quantum cascade laser...
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A ppb-level nitric oxide (NO) photoacoustic sensor was reported for outdoor environmental monitoring. The sensor employed a continuous wave (CW), distributed feedback (DFB), mid-infrared (mid-IR) quantum cascade laser (QCL) operating at a high temperature of 52 °C, which allow avoiding any water-cooling systems and thereby reduces its size, weight and cost of the photoacoustic NO sensor. The QCL emits at 5.26 μm, which corresponds to a strong NO absorption doublet R (6.5). A differential photoacoustic cell was designed to operate together with the QCL, resulting in a detection sensitivity of ˜7 ppb at atmospheric pressure with a 1-s averaging time. An Allan–Werle deviation analysis indicated that a ppt-level detection sensitivity can be reached with an integration time of >100 s. The performance of this sensor system was evaluated in terms of humidity, linearity and stability. Continuous measurements covering a haze period were performed to demonstrate the stability and robustness of the reported NO sensor system.
Depth Image-Based Rendering (DIBR) is an approach to generate a 3-D image by the original 2-D color image with the corresponding 2-D depth map. Although DIBR is a quite convenient to convert 2D images to 3D ones, ther...
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Motivated by index-tuning-to-loss tradeoff dictated by fundamental Kramers-Kronig relations, this work demonstrates a comprehensive analysis for high-performance compact on-chip electro-optic modulators for a selected...
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We report the experimental observation of strongly enhanced tunneling between graphene bilayers through a WSe2 barrier when the graphene bilayers are populated with carriers of opposite polarity and equal density. The...
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We report the experimental observation of strongly enhanced tunneling between graphene bilayers through a WSe2 barrier when the graphene bilayers are populated with carriers of opposite polarity and equal density. The enhanced tunneling increases sharply in strength with decreasing temperature, and the tunneling current exhibits a vertical onset as a function of interlayer voltage at a temperature of 1.5 K. The strongly enhanced tunneling at overall neutrality departs markedly from single-particle model calculations that otherwise match the measured tunneling current-voltage characteristics well, and suggests the emergence of a many-body state with condensed interbilayer excitons when electrons and holes of equal densities populate the two layers.
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