9,879 research outputs found
2-Phenyl-4-(3,4,5-trimethoxybenzylidene)-1,3-oxazol-5(4H)-one
The title compound, C19H17NO5, was synthesized as part of a continuing project involving the structures of oxazolone derivatives. The molecule adopts a Z configuration about the central olefinic bond. The 2-phenyl ring is slightly twisted out of the plane of the oxazolone ring system by 11.2 (2)°. The crystal structure is stabilized by weak intermolecular C—H⋯O hydrogen bonds
IOPS: An Unified SpMM Accelerator Based on Inner-Outer-Hybrid Product
Sparse matrix multiplication (SpMM) is widely applied to numerous domains,
such as graph processing, machine learning, and data analytics. However, inner
product based SpMM induces redundant zero-element computing for mismatched
nonzero operands, while outer product based approach lacks input reuse across
Process Elements (PEs) and poor output locality for accumulating partial sum
(psum) matrices. Besides, current works only focus on sparse-sparse matrix
multiplication (SSMM) or sparse-dense matrix multiplication (SDMM), rarely
performing efficiently for both. To address these problems, this paper proposes
an unified SpMM accelerator, called IOPS, hybridizing inner with outer
products. It reuses the input matrix among PEs with inner product dataflow, and
removes zero-element calculations with outer product approach in each PE, which
can efficiently process SSMM and SDMM. Moreover, an address mapping method is
designed to accumulate the irregular sparse psum matrices, reducing the latency
and DRAM access of psum accumulating. Furthermore, an adaptive partition
strategy is proposed to tile the input matrices based on their sparsity ratios,
effectively utilizing the storage of architecture and reducing DRAM access.
Compared with the SSMM accelerator, SpArch, we achieve 1.7x~6.3x energy
efficiency and 1.2x~4.4x resource efficiency, with 1.4x~2.1x DRAM access
saving
Improvement of two-way continuous-variable quantum key distribution using optical amplifiers
The imperfections of a receiver's detector affect the performance of two-way
continuous-variable quantum key distribution protocols and are difficult to
adjust in practical situations. We propose a method to improve the performance
of two-way continuous-variable quantum key distribution by adding a
parameter-adjustable optical amplifier at the receiver. A security analysis is
derived against a two-mode collective entangling cloner attack. Our simulations
show that the proposed method can improve the performance of protocols as long
as the inherent noise of the amplifier is lower than a critical value, defined
as the tolerable amplifier noise. Furthermore, the optimal performance can
approach the scenario where a perfect detector is used.Comment: 14 pages, 7 figure
Sense: Model Hardware Co-design for Accelerating Sparse CNN on Systolic Array
Sparsity is an intrinsic property of convolutional neural network(CNN) and
worth exploiting for CNN accelerators, but extra processing comes with hardware
overhead, causing many architectures suffering from only minor profit.
Meanwhile, systolic array has been increasingly competitive on CNNs
acceleration for its high spatiotemporal locality and low hardware overhead.
However, the irregularity of sparsity induces imbalanced workload under the
rigid systolic dataflow, causing performance degradation. Thus, this paper
proposed a systolicarray-based architecture, called Sense, for sparse CNN
acceleration by model-hardware co-design, achieving large performance
improvement. To balance input feature map(IFM) and weight loads across
Processing Element(PE) array, we applied channel clustering to gather IFMs with
approximate sparsity for array computation, and co-designed a load-balancing
weight pruning method to keep the sparsity ratio of each kernel at a certain
value with little accuracy loss, improving PE utilization and overall
performance. Additionally, Adaptive Dataflow Configuration is applied to
determine the computing strategy based on the storage ratio of IFMs and
weights, lowering 1.17x-1.8x DRAM access compared with Swallow and further
reducing system energy consumption. The whole design is implemented on
ZynqZCU102 with 200MHz and performs at 471-, 34-, 53- and 191-image/s for
AlexNet, VGG-16, ResNet-50 and GoogleNet respectively. Compared against sparse
systolic-array-based accelerators, Swallow, FESA and SPOTS, Sense achieves
1x-2.25x, 1.95x-2.5x and 1.17x-2.37x performance improvement on these CNNs
respectively with reasonable overhead.Comment: 14 pages, 29 figures, 6 tables, IEEE TRANSACTIONS ON VERY LARGE SCALE
INTEGRATION (VLSI) SYSTEM
Quantum electric-dipole liquid on a triangular lattice
Geometric frustrations and quantum mechanical fluctuations may prohibit the
formation of long-range ordering even at the lowest temperature, and therefore
liquid-like ground states could be expected. A good example is the quantum spin
liquid in frustrated magnets that represents an exotic phase of matter and is
attracting enormous interests. Geometric frustrations and quantum fluctuations
can happen beyond magnetic systems. Here we propose that quantum
electric-dipole liquids, analogs to quantum spin liquids, could emerge in
frustrated dielectrics where antiferroelectrically coupled small electric
dipoles reside on a triangular lattice. The quantum paraelectric hexaferrite
BaFe12O19, in which small electric dipoles originated from the off-center
displacement of Fe3+ in the FeO5 bipyramids constitute a two-dimensional
triangular lattice, represents a promising candidate to generate the
anticipated electric-dipole liquid. We present a series of experimental
evidences, including dielectric permittivity, heat capacity, and thermal
conductivity measured down to 66 mK, to reveal the existence of a nontrivial
ground state in BaFe12O19, characterized by itinerant low-energy excitations
with a small gap, to which we interpret as an exotic liquid-like quantum phase.
The quantum electric-dipole liquids in frustrated dielectrics open up a fresh
playground for fundamental physics and may find applications in quantum
information and computation as well.Comment: 13 pages, 6 figure
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