120 research outputs found
Modeling Scalability of Distributed Machine Learning
Present day machine learning is computationally intensive and processes large
amounts of data. It is implemented in a distributed fashion in order to address
these scalability issues. The work is parallelized across a number of computing
nodes. It is usually hard to estimate in advance how many nodes to use for a
particular workload. We propose a simple framework for estimating the
scalability of distributed machine learning algorithms. We measure the
scalability by means of the speedup an algorithm achieves with more nodes. We
propose time complexity models for gradient descent and graphical model
inference. We validate our models with experiments on deep learning training
and belief propagation. This framework was used to study the scalability of
machine learning algorithms in Apache Spark.Comment: 6 pages, 4 figures, appears at ICDE 201
Loss-tolerant quantum enhanced metrology and state engineering via the reverse Hong-Ou-Mandel effect
Preparing highly entangled quantum states between remote parties is a major
challenge for quantum communications [1-8]. Particularly promising in this
context are the N00N states, which are entangled N-photon wavepackets
delocalized between two different locations, providing measurement sensitivity
limited only by the uncertainty principle [1, 10-15]. However, these states are
notoriously vulnerable to losses, making it difficult both to share them
between remote locations, and to recombine them to exploit interference
effects. Here we address this challenge by utilizing the reverse version of the
Hong-Ou-Mandel effect [16] to prepare a high-fidelity two-photon N00N state
shared between two parties connected by a lossy optical channel. Furthermore,
we demonstrate that the enhanced phase sensitivity can be directly exploited in
the two distant locations, and we remotely prepare superpositions of coherent
states, known as Schr\"odinger's cat states" [17, 18]
Synthesis of the Einstein-Podolsky-Rosen entanglement in a sequence of two single-mode squeezers
Synthesis of the Einstein-Podolsky-Rosen entangled state --- the primary
entangled resource in continuous-variable quantum-optical information
processing --- is a technological challenge of great importance. Here we
propose and implement a new scheme of generating this state. Two nonlinear
optical crystals, positioned back-to-back in the waist of a pump beam, function
as single-pass degenerate optical parametric amplifiers and produce single-mode
squeezed vacuum states in orthogonal polarization modes, but in the same
spatiotemporal mode. A subsequent pair of waveplates acts as a beam splitter,
entangling the two polarization modes to generate the Einstein-Podolsky-Rosen
state. This technique takes advantage of the strong nonlinearity associated
with type-I phase-matching configuration while at the same time eliminating the
need for actively stabilizing the optical phase between the two squeezers,
which typically arises if these squeezers are spatially separated. We
demonstrate our method in an experiment, preparing a 1.4 dB two-mode squeezed
state and characterizing it via two-mode homodyne tomography.Comment: 4 pages, 3 figure
Russian and American Poetry: Towards New Language Abilities
The book by Vladimir Feshchenko, a Russian researcher of the language of poetry and a publisher of avant-garde literature, is devoted to Russian and American poetry of the language experiment in the 20th and early 21st century. Using examples from Andrei Bely, Russian futurists, Alexander Vvedensky, Ezra Pound, Gertrude Stein, E.E. Cummings to the American poets of “language writing” and modern Russian-speaking young poets, the similarity of the philosophical and linguistic foundations of the language experiment, the convergence and differences of literatures, the personal interaction of authors from both countries are considered in the book. The analysis of a number of American and Russian poems from the point of view of the language of poetry is given. V. Feshchenko's book is of interest to researchers of Russian and American poetry, the avant-garde, the language of poetry, and the interaction of literatures
Annealing by simulating the coherent Ising machine
The coherent Ising machine (CIM) enables efficient sampling of low-lying
energy states of the Ising Hamiltonian with all-to-all connectivity by encoding
the spins in the amplitudes of pulsed modes in an optical parametric oscillator
(OPO). The interaction between the pulses is realized by means of
measurement-based optoelectronic feedforward which enhances the gain for
lower-energy spin configurations. We present an efficient method of simulating
the CIM on a classical computer that outperforms the CIM itself as well as the
noisy mean-field annealer in terms of both the quality of the samples and the
computational speed. It is furthermore advantageous with respect to the CIM in
that it can handle Ising Hamiltonians with arbitrary real-valued node coupling
strengths. These results illuminate the nature of the faster performance
exhibited by the CIM and may give rise to a new class of quantum-inspired
algorithms of classical annealing that can successfully compete with existing
methods
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