5,573 research outputs found
CloudJet4BigData: Streamlining Big Data via an Accelerated Socket Interface
Big data needs to feed users with fresh processing results and cloud platforms can be used to speed up big data applications. This paper describes a new data communication protocol (CloudJet) for long distance and large volume big data accessing operations to alleviate the large latencies encountered in sharing big data resources in the clouds. It encapsulates a dynamic multi-stream/multi-path engine at the socket level, which conforms to Portable Operating System Interface (POSIX) and thereby can accelerate any POSIX-compatible applications across IP based networks. It was demonstrated that CloudJet accelerates typical big data applications such as very large database (VLDB), data mining, media streaming and office applications by up to tenfold in real-world tests
Massively Parallel Video Networks
We introduce a class of causal video understanding models that aims to
improve efficiency of video processing by maximising throughput, minimising
latency, and reducing the number of clock cycles. Leveraging operation
pipelining and multi-rate clocks, these models perform a minimal amount of
computation (e.g. as few as four convolutional layers) for each frame per
timestep to produce an output. The models are still very deep, with dozens of
such operations being performed but in a pipelined fashion that enables
depth-parallel computation. We illustrate the proposed principles by applying
them to existing image architectures and analyse their behaviour on two video
tasks: action recognition and human keypoint localisation. The results show
that a significant degree of parallelism, and implicitly speedup, can be
achieved with little loss in performance.Comment: Fixed typos in densenet model definition in appendi
Accelerated hot-carrier cooling in MAPbI3 perovskite by pressure-induced lattice compression
Hot-carrier cooling (HCC) in metal halide perovskites in the high-density
regime is significantly slower compared to conventional semiconductors. This
effect is commonly attributed to a hot-phonon bottleneck but the influence of
the lattice properties on the HCC behaviour is poorly understood. Using
pressure-dependent transient absorption spectroscopy (fs-TAS) we find that at
an excitation density below Mott transition, pressure does not affect the HCC.
On the contrary, above Mott transition, HCC in methylammonium lead iodide
(MAPbI3) is around two times as fast at 0.3 GPa compared to ambient pressure.
Our electron-phonon coupling calculations reveal about two times stronger
electron-phonon coupling for the inorganic cage mode at 0.3 GPa. However, our
experiments reveal that pressure promotes faster HCC only above Mott
transition. Altogether, these findings suggest a change in the nature of
excited carriers in the high-density regime, providing insights on the
electronic behavior of devices operating at such high charge-carrier density
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