17,410 research outputs found
Radio-frequency spectroscopy of weakly bound molecules in spin-orbit coupled atomic Fermi gases
We investigate theoretically radio-frequency spectroscopy of weakly bound
molecules in an ultracold spin-orbit-coupled atomic Fermi gas. We consider two
cases with either equal Rashba and Dresselhaus coupling or pure Rashba
coupling. The former system has been realized very recently at Shanxi
University [Wang et al., arXiv:1204.1887] and MIT [Cheuk et al.,
arXiv:1205.3483]. We predict realistic radio-frequency signals for revealing
the unique properties of anisotropic molecules formed by spin-orbit coupling.Comment: 11 pages, 7 figure
Spice up Your Chat: The Intentions and Sentiment Effects of Using Emoji
Emojis, as a new way of conveying nonverbal cues, are widely adopted in
computer-mediated communications. In this paper, first from a message sender
perspective, we focus on people's motives in using four types of emojis --
positive, neutral, negative, and non-facial. We compare the willingness levels
of using these emoji types for seven typical intentions that people usually
apply nonverbal cues for in communication. The results of extensive statistical
hypothesis tests not only report the popularities of the intentions, but also
uncover the subtle differences between emoji types in terms of intended uses.
Second, from a perspective of message recipients, we further study the
sentiment effects of emojis, as well as their duplications, on verbal messages.
Different from previous studies in emoji sentiment, we study the sentiments of
emojis and their contexts as a whole. The experiment results indicate that the
powers of conveying sentiment are different between four emoji types, and the
sentiment effects of emojis vary in the contexts of different valences.Comment: 10 pages, published at ICWSM'1
An MPI-OpenMP Hybrid Parallel H
In this paper we propose a high performance parallel strategy/technique to implement the fast direct solver based on hierarchical matrices method. Our goal is to directly solve electromagnetic integral equations involving electric-large and geometrical-complex targets, which are traditionally difficult to be solved by iterative methods. The parallel method of our direct solver features both OpenMP shared memory programming and MPl message passing for running on a computer cluster. With modifications to the core direct-solving algorithm of hierarchical LU factorization, the new fast solver is scalable for parallelized implementation despite of its sequential nature. The numerical experiments demonstrate the accuracy and efficiency of the proposed parallel direct solver for analyzing electromagnetic scattering problems of complex 3D objects with nearly 4 million unknowns
0- qubit in one Josephson junction
Quantum states are usually fragile which makes quantum computation being not
as stable as classical computation. Quantum correction codes can protect
quantum states but need a large number of physical qubits to code a single
logic qubit. Alternatively, the protection at the hardware level has been
recently developed to maintain the coherence of the quantum information by
using symmetries. However, it generally has to pay the expense of increasing
the complexity of the quantum devices. In this work, we show that the
protection at the hardware level can be approached without increasing the
complexity of the devices. The interplay between the spin-orbit coupling and
the Zeeman splitting in the semiconductor allows us to tune the Josephson
coupling in terms of the spin degree of freedom of Cooper pairs, the hallmark
of the superconducting spintronics. This leads to the implementation of the
parity-protected 0- superconducting qubit with only one highly transparent
superconductor-semiconductor Josephson junction, which makes our proposal
immune from the various fabrication imperfections.Comment: 5 pages, 4 figure
A butterflyâbased direct solver using hierarchical LU factorization for PoggioâMillerâChangâHarringtonâWuâTsai equations
A butterflyâbased hierarchical LU factorization scheme for solving the PMCHWT equations for analyzing scattering from homogenous dielectric objects is presented. The proposed solver judiciously reâorders the discretized integral operator and butterflyâcompresses blocks in the operator and its LU factors. The observed memory and CPU complexities scale as O(N log2 N) and O(N1.5 log N), respectively. The proposed solver is applied to the analyses of scattering several largeâscale dielectric objects.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/143676/1/mop31166.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/143676/2/mop31166_am.pd
Applying Opponent Modeling for Automatic bidding in Online Repeated Auctions
Online auction scenarios, such as bidding searches on advertising platforms,
often require bidders to participate repeatedly in auctions for the same or
similar items. We design an algorithm for adaptive automatic bidding in
repeated auctions in which the seller and other bidders also update their
strategies. We apply and improve the opponent modeling algorithm to allow
bidders to learn optimal bidding strategies in this multiagent reinforcement
learning environment. The algorithm uses almost no private information about
the opponent or restrictions on the strategy space, so it can be extended to
multiple scenarios. Our algorithm improves the utility compared to both static
bidding strategies and dynamic learning strategies. We hope the application of
opponent modeling in auctions will promote the research of automatic bidding
strategies in online auctions and the design of non-incentive compatible
auction mechanisms
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