335 research outputs found
Reconfigurable interconnects in DSM systems: a focus on context switch behavior
Recent advances in the development of reconfigurable optical interconnect technologies allow for the fabrication of low cost and run-time adaptable interconnects in large distributed shared-memory (DSM) multiprocessor machines. This can allow the use of adaptable interconnection networks that alleviate the huge bottleneck present due to the gap between the processing speed and the memory access time over the network. In this paper we have studied the scheduling of tasks by the kernel of the operating system (OS) and its influence on communication between the processing nodes of the system, focusing on the traffic generated just after a context switch. We aim to use these results as a basis to propose a potential reconfiguration of the network that could provide a significant speedup
8x14Gb/s ring WDM modulator array with integrated tungsten heaters and Ge monitor photodetectors
An 8x14Gb/s wavelength-division multiplexed Si ring modulator array is presented with uniform channel performance. Tungsten heaters and Ge monitor photodetectors at the ring modulator drop ports are co-integrated to track and control the modulation quality
Optical interconnect with densely integrated plasmonic modulator and germanium photodetector arrays
We demonstrate the first chip-to-chip interconnect utilizing a densely integrated plasmonic Mach-Zehnder modulator array operating at 3 x 10 Gbit/s. A multicore fiber provides a compact optical interface, while the receiver consists of germanium photodetectors
An experimental realisation of steady spanwise forcing for turbulent drag reduction
We present an experimental realisation of spatial spanwise forcing in a
turbulent boundary layer flow, aimed at reducing the frictional drag. The
forcing is achieved by a series of spanwise running belts, running in
alternating spanwise direction, thereby generating a steady spatial square-wave
forcing. Stereoscopic particle image velocimetry is used to investigate the
impact of actuation on the flow in terms of turbulence statistics, performance
characteristics, and spanwise velocity profiles, for a waveform of . An extension of the classical spatial Stokes layer theory is proposed
based on the linear superposition of Fourier modes to describe the
non-sinusoidal boundary condition. The experimentally obtained spanwise
profiles show good agreement with the extended theoretical model. In line with
reported numerical studies, we confirm that a significant flow control effect
can be realised with this type of forcing. The results reveal a maximum drag
reduction of 26% and a maximum net power savings of 8%. In view of the limited
spatial extent of the actuation surface in the current setup, the drag
reduction is expected to increase further as a result of its streamwise
transient. The second-order turbulence statistics are attenuated up to a
wall-normal height of , with a maximum streamwise stress
reduction of 44% and a reduction of integral turbulence kinetic energy
production of 39%
Optical interconnect solution with plasmonic modulator and Ge photodetector array
We report on an optical chip-to-chip interconnect solution, thereby demonstrating plasmonics as a solution for ultra-dense, high-speed short-reach communications. The interconnect comprises a densely integrated plasmonic Mach-Zehnder modulator array that is packaged with standard driving electronics. On the receiver side, a germanium photodetector array is integrated with trans-impedance amplifiers. A multicore fiber provides a compact optical interface to the array. We demonstrate 4 × 20 Gb/s on-off keying signaling with direct detection.ISSN:1041-1135ISSN:1941-017
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