8,642 research outputs found

    Soft lithography molding of polymer integrated optical devices: Reduction of the background residue

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    Soft lithography molding is a promising technique for patterning polymer integrated optical devices, however the presence of a background residue has the potential to limit the usefulness of this technique. We present the soft lithography technique for fabricating polymer waveguides. Several effects of the background residue are investigated numerically, including the modal properties of an individual waveguide, the coupling ratio of a directional coupler, and the radiation loss in a waveguide bend. Experimentally, the residue is found to be reduced through dilution of the core polymer solution. We find that the force with which the soft mold is depressed on the substrate does not appreciably affect the waveguide thickness or the residue thickness. Optical microscope images show that the residue is thinnest next to the waveguide

    Soft lithography replication of polymeric microring optical resonators

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    We have developed a soft lithography method to replicate polymeric integrated optical devices. In this method, the master device and the molded replica are made of the same materials, allowing direct comparison. To evaluate the quality of the replication, microring optical resonators are chosen as test devices because of their sensitivity to small fabrication errors. The master devices are precisely fabricated using direct electron beam lithography. The replicas are produced by the molding technique and subsequent ultraviolet curing. Compared with the master devices, the molded devices show minimal change in both physical shape and optical performance. This correspondence indicates the merits of soft lithographic methods for fabrication of precision integrated optical devices

    Statistical Machine Translation Features with Multitask Tensor Networks

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    We present a three-pronged approach to improving Statistical Machine Translation (SMT), building on recent success in the application of neural networks to SMT. First, we propose new features based on neural networks to model various non-local translation phenomena. Second, we augment the architecture of the neural network with tensor layers that capture important higher-order interaction among the network units. Third, we apply multitask learning to estimate the neural network parameters jointly. Each of our proposed methods results in significant improvements that are complementary. The overall improvement is +2.7 and +1.8 BLEU points for Arabic-English and Chinese-English translation over a state-of-the-art system that already includes neural network features.Comment: 11 pages (9 content + 2 references), 2 figures, accepted to ACL 2015 as a long pape

    Dendritic side-branching with anisotropic viscous fingering

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    We studied dendritic side-branching mechanism in the experiment of anisotropic viscous fingering. We measured the time dependence of growth speed of side-branch and the envelop of side-branches. We found that the speed of side-branch gets to be faster than one of the stem and the growth exponent of the speed changes at a certain time. The envelope of side-branches is represented as Y ~ X^1.47.Comment: 8 pages, 8 figures, to submited in J. Crystal Growt

    A Survey of Current Datasets for Vision and Language Research

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    Integrating vision and language has long been a dream in work on artificial intelligence (AI). In the past two years, we have witnessed an explosion of work that brings together vision and language from images to videos and beyond. The available corpora have played a crucial role in advancing this area of research. In this paper, we propose a set of quality metrics for evaluating and analyzing the vision & language datasets and categorize them accordingly. Our analyses show that the most recent datasets have been using more complex language and more abstract concepts, however, there are different strengths and weaknesses in each.Comment: To appear in EMNLP 2015, short proceedings. Dataset analysis and discussion expanded, including an initial examination into reporting bias for one of them. F.F. and N.M. contributed equally to this wor

    Spotlight on Poland: Negative Views of Russia Surge, but Ratings for U.S., NATO, EU Improve

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    The Russian invasion of Ukraine has led to a dramatic shift in attitudes in Poland, a key European partner and one which only three decades ago was part of the former Soviet Union's Eastern Bloc. Negative attitudes among Poles towards Russia are at all-time highs since Pew Research Center began tracking opinion on this question in 2007, with virtually unanimous negative opinions of the Russian state. Currently, 94% see Russia as a major threat, up from 65% who said this in 2018, and 94% have no confidence at all in Russian President Vladimir Putin -- also an all-time high. The sharp decline in positive attitudes toward Russia has benefited Poland's western allies, specifically the United States, the North Atlantic Treaty Organization (NATO) and the European Union (Poland is a member of both NATO and the EU). Around nine-in-ten Poles have a favorable view of the U.S., NATO and the EU, all of which represent the highest shares since 2007. In terms of Poland's relationship with the U.S., the increase in favorable attitudes toward America coincides with a strong 82% confidence rating for U.S. President Joe Biden, a marked increase from the 51% who had confidence in former President Donald Trump in 2019. In addition, roughly two-thirds in Poland see having a close relationship with the U.S. as more important than having one with Russia. Only 1% want a closer relationship with Russia, while 28% volunteer that both are equally important. Just three years ago, more than half of Poles (53%) offered that both relationships are equally important
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