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Full-Text Articles in Engineering
Masking Schemes For Image Manifolds, Hamid Dadkhahi, Marco Duarte
Masking Schemes For Image Manifolds, Hamid Dadkhahi, Marco Duarte
Marco Duarte
We consider the problem of selecting an optimal mask for an image manifold, i.e., choosing a subset of the dimensions of the image space that preserves the manifold structure present in the original data. Such masking implements a form of compressed sensing that reduces power consumption in emerging imaging sensor platforms. Our goal is for the manifold learned from masked images to resemble the manifold learned from full images as closely as possible. We show that the process of finding the optimal masking pattern can be cast as a binary integer program, which is computationally expensive but can be approximated …
Complexity-Adaptive Universal Signal Estimation For Compressed Sensing, Junan Zhu, Dror Baron, Marco Duarte
Complexity-Adaptive Universal Signal Estimation For Compressed Sensing, Junan Zhu, Dror Baron, Marco Duarte
Marco Duarte
We study the compressed sensing (CS) signal estimation problem where a signal is measured via a linear matrix multiplication under additive noise. While this setup usually assumes sparsity or compressibility in the signal during estimation, additional signal structure that can be leveraged is often not known a priori. For signals with independent and identically distributed (i.i.d.) entries, existing CS algorithms achieve optimal or near optimal estimation error without knowing the statistics of the signal. This paper addresses estimating stationary ergodic non-i.i.d. signals with unknown statistics. We have previously proposed a universal CS approach to simultaneously estimate the statistics of a …
Concentric Rings Of Polystyrene And Titanium Dioxide Nanoparticles Patterned By Alternating Current Signal Guided Coffee Ring Effect, Jinhua Mu, Peng Lin, Qiangfei Xia
Concentric Rings Of Polystyrene And Titanium Dioxide Nanoparticles Patterned By Alternating Current Signal Guided Coffee Ring Effect, Jinhua Mu, Peng Lin, Qiangfei Xia
Qiangfei Xia
The authors studied the surface deposition of nanoparticles by introducing an alternating current (AC) signal into the millimeter-sized nanoparticle droplet. For both polystyrene (PS) in deionized (DI) water and titanium dioxide (TiO2) in toluene, the nanoparticles self-assembled into regular concentric rings over a larger area on the substrate during the droplet drying process. The patterned area decreased, and the inter-ring spacing increased with higher AC frequencies for the TiO2/toluene system, while those for the PS/DI water system only changed slightly. The frequency dependent pattern formation was interpreted by the interaction between different factors such as capillary flow and the AC …
Single- And Bi-Layer Memristive Devices With Tunable Properties Using Tiox Switching Layers Deposited By Reactive Sputtering, Hao Jiang, Qiangfei Xia
Single- And Bi-Layer Memristive Devices With Tunable Properties Using Tiox Switching Layers Deposited By Reactive Sputtering, Hao Jiang, Qiangfei Xia
Qiangfei Xia
The authors systematically studied reactive sputtering deposition of TiOx thin films using a mixture of Ar and O2 gases under different ratios of O2 flow. As directly revealed by X-ray photoelectron spectroscopy, the deposition changed from a metallic Ti target mode to an oxide target mode when the O2 flow ratio was beyond 40%, resulting in TiOx thin films with different chemical compositions. Consequently, metal/oxide/metal devices with a single TiOx layer exhibited a broad spectrum of electrical characteristics such as Ohmic, rectifying, and memristive behavior. The reactive sputtering deposited TiOx thin films were also used in a bilayer memristive device …
3d Integration Of Planar Crossbar Memristive Devices With Cmos Substrate, Peng Lin, Shuang Pi, Qiangfei Xia
3d Integration Of Planar Crossbar Memristive Devices With Cmos Substrate, Peng Lin, Shuang Pi, Qiangfei Xia
Qiangfei Xia
Memristive devices are promising building blocks for enhanced CMOS hardware in data storage and computing. Nanoimprint lithography (NIL) has been an enabling technology in the past decade for exploring novel devices and circuits. In this paper, the authors review the progress and technical aspects of the fabrication and integration of memristor crossbar arrays using NIL. Since the key component of successful fabrication is the imprint mold, the material selection, master mold fabrication, anti-sticking treatment and cleaning are first discussed. The requirements and composition of imprint resists, in particular low-viscosity liquid resists that cross-link upon ultraviolet light radiation, are investigated next. …