8,437 research outputs found
Soft lithography molding of polymer integrated optical devices: Reduction of the background residue
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
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
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
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
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The Effect of Haptic Feedback on Efficiency and Safety During Preretinal Membrane Peeling Simulation.
PurposeWe determine whether haptic feedback improves surgical performance and outcome during simulated a preretinal membrane peeling procedure.MethodsA haptic-enabled virtual reality preretinal membrane peeling simulator was developed using a surgical cockpit with two multifinger haptic devices. Six subjects (three trained retina surgeons and three nonsurgeons) performed the preretinal membrane peeling surgical procedure using two modes of operation: visual and haptic feedback, and visual feedback only.ResultsTask completion time, tool tip path trajectory, tool-retina collision force, and retinal damage were all reduced with haptic feedback used and compared to modes where haptic feedback was disabled.ConclusionsHaptic feedback improves efficiency and safety during preretinal membrane peeling simulation.Translational relevanceThese findings highlight the potential benefit of haptic feedback for improving performance and safety of vitreoretinal surgery
A Survey of Current Datasets for Vision and Language Research
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
Near infrared spectroscopy of the type IIn SN 2010jl: evidence for high velocity ejecta
The Type IIn supernova SN 2010jl was relatively nearby and luminous, allowing
detailed studies of the near-infrared (NIR) emission. We present 1 - 2.4 micron
spectroscopy over the age range of 36 - 565 days from the earliest detection of
the supernova. On day 36, the H lines show an unresolved narrow emission
component along with a symmetric broad component that can be modeled as the
result of electron scattering by a thermal distribution of electrons. Over the
next hundreds of days, the broad components of the H lines shift to the blue by
700 km/s, as is also observed in optical lines. The narrow lines do not show a
shift, indicating they originate in a different region. He I 1.0830 and 2.0587
micron lines both show an asymmetric broad emission component, with a shoulder
on the blue side that varies in prominence and velocity from -5500 km/s on day
108 to -4000 km/s on day 219. This component may be associated with the higher
velocity flow indicated by X-ray observations of the supernova. The absence of
the feature in the H lines suggests that this is from a He rich ejecta flow.
The He I 1.0830 micron feature has a narrow P Cygni line, with absorption
extending to ~100 km/s and strengthening over the first 200 days, and an
emission component which weakens with time. At day 403, the continuum emission
becomes dominated by a blackbody spectrum with a temperature of ~1900 K,
suggestive of dust emission.Comment: 17 pages, 18 figure
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