arXiv subjects

Runyu Zhang

Publications and source records attributed to Runyu Zhang.

39 records · Page 3Linked to original sources

arXiv2020

An Efficient and Wear-Leveling-Aware Frequent-Pattern Mining on Non-Volatile Memory

Frequent-pattern mining is a common approach to reveal the valuable hidden trends behind data. However, existing frequent-pattern mining algorithms are designed for DRAM, instead of persistent memories (PMs), which can lead to severe performance and energy overhead due to the utterly different characteristics between DRAM and PMs when they are running on PMs. In this paper, we propose an efficient and Wear-leveling-aware Frequent-Pattern Mining scheme, WFPM, to solve this problem. The proposed WFPM is evaluated by a series of experiments based on realistic datasets from diversified application scenarios, where WFPM achieves 32.0% performance improvement and prolongs the NVM lifetime of header table by 7.4x over the EvFP-Tree.

cs.DB↗

arXiv2019

Reconstruct the Directories for In-Memory File Systems

Existing path lookup routines in file systems need to construct an auxiliary index in memory or traverse the dentries of the directory file sequentially, which brings either heavy writes or large timing cost. This paper designs a novel path lookup mechanism, Content-Indexed Browsing (CIB), for file systems on persistent memory, in which the structure of directory files is an exclusive index that can be searched in $O(log(n))$ time. We implement CIB in a real persistent memory file system, PMFS, denoted by CIB-PMFS. Comprehensive evaluations show that CIB can achieve times of performance improvement over the conventional lookup schemes in PMFS, and brings 20.4\% improvement on the overall performance of PMFS. Furthermore, CIB reduces the writes on persistent memory by orders of magnitude comparing with existing extra index schemes.

cs.DC↗

arXiv2016

Three-dimensional single gyroid photonic crystals with a mid-infrared bandgap

A gyroid structure is a distinct morphology that is triply periodic and consists of minimal isosurfaces containing no straight lines. We have designed and synthesized amorphous silicon (a-Si) mid-infrared gyroid photonic crystals that exhibit a complete bandgap in infrared spectroscopy measurements. Photonic crystals were synthesized by deposition of a-Si/Al2O3 coatings onto a sacrificial polymer scaffold defined by two-photon lithography. We observed a 100% reflectance at 7.5 \mum for single gyroids with a unit cell size of 4.5 \mum, in agreement with the photonic bandgap position predicted from full-wave electromagnetic simulations, whereas the observed reflection peak shifted to 8 um for a 5.5 \mum unit cell size. This approach represents a simulation-fabrication-characterization platform to realize three-dimensional gyroid photonic crystals with well-defined dimensions in real space and tailored properties in momentum space.

physics.optics↗