3,604 research outputs found
Pixel Burn-In Compensation Parameter Compression for Organic Light Emitting Diode Displays
This publication describes techniques directed to improved compression algorithms that reduce the size of look-up tables used to store pixel burn-in compensation parameters that are used by Organic Light Emitting Diode (OLED) display burn-in compensation algorithms. The improved compression algorithms include an x-y mapping compression algorithm and a line fitting parameters compression algorithm. The improved compression algorithms simplify logic, save memory space, conserve power, and/or reduce latency relative to many common compression techniques
The quality management ecosystem for predictive maintenance in the Industry 4.0 era
The Industry 4.0 era requires new quality management systems due to the ever increasing complexity of the global business environment and the advent of advanced digital technologies. This study presents new ideas for predictive quality management based on an extensive review of the literature on quality management and five realworld cases of predictive quality management based on new technologies. The results of the study indicate that advanced technology enabled predictive maintenance can be applied in various industries by leveraging big data analytics, smart sensors, artificial intelligence (AI), and platform construction. Such predictive quality management systems can become living ecosystems that can perform cause-effect analysis, big data monitoring and analytics, and effective decision-making in real time. This study proposes several practical implications for actual design and implementation of effective predictive quality management systems in the Industry 4.0 era. However, the living predictive quality management ecosystem should be the product of the organizational culture that nurtures collaborative efforts of all stakeholders, sharing of information, and co-creation of shared goals
The quality management ecosystem for predictive maintenance in the Industry 4.0 era
The Industry 4.0 era requires new quality management systems due to the ever increasing complexity of the global business environment and the advent of advanced digital technologies. This study presents new ideas for predictive quality management based on an extensive review of the literature on quality management and five realworld cases of predictive quality management based on new technologies. The results of the study indicate that advanced technology enabled predictive maintenance can be applied in various industries by leveraging big data analytics, smart sensors, artificial intelligence (AI), and platform construction. Such predictive quality management systems can become living ecosystems that can perform cause-effect analysis, big data monitoring and analytics, and effective decision-making in real time. This study proposes several practical implications for actual design and implementation of effective predictive quality management systems in the Industry 4.0 era. However, the living predictive quality management ecosystem should be the product of the organizational culture that nurtures collaborative efforts of all stakeholders, sharing of information, and co-creation of shared goals
Quantitative understanding of magnetic vortex oscillations driven by spin-polarized out-of-plane dc current: Analytical and micromagnetic numerical study
We studied magnetic vortex oscillations associated with vortex gyrotropic
motion driven by spin-polarized out-of-plane dc current by analytical and
micromagnetic numerical calculations. Reliable controls of the tunable
eigenfrequency and orbital amplitude of persistent vortex oscillations were
demonstrated. This work provides an advanced step towards the practical
application of vortex oscillations to persistent vortex oscillators in a wide
frequency (f) range of 10 to 2000 MHz and with high values of f/(delta f).Comment: 27 pages, 4 figures, 2 table
Reliable low-power control of ultrafast vortex-core switching with the selectivity in an array of vortex states by in-plane circular-rotational magnetic fields and spin-polarized currents
The authors investigated the technological utility of counterclockwise (CCW) and clockwise (CW) circular-rotating fields (HCCW and HCW) and spin-polarized currents with an angular frequency ??H close to the vortex eigenfrequency ??D, for the reliable, low-power, and selective switching of the bistate magnetization (M) orientations of a vortex core (VC) in an array of soft magnetic nanoelements. CCW and CW circular gyrotropic motions in response to HCCW and HCW, respectively, show remarkably contrasting resonant behaviors, (i.e., extremely large-amplitude resonance versus small-amplitude nonresonance), depending on the M orientation of a given VC. Owing to this asymmetric resonance characteristics, the HCCW (HCW) with ??H ??? ??D can be used to effectively switch only the up (down) core to its downward (upward) M orientation, selectively, by sufficiently low field (???10 Oe) and current density (??? 107 A cm2). This work provides a reliable, low power, effective means of information storage, information recording, and information readout in vortex-based random access memory, simply called VRAM.open906
Understanding eigenfrequency shifts observed in vortex gyrotropic motions in a magnetic nanodot driven by spin-polarized out-of-plane dccurrent
We observed sizable eigenfrequency shifts in spin-polarized dc-current-driven vortex gyrotropic motions in a soft magnetic nanodot, and clarified the underlying physics through micromagnetic numerical calculations. It was found that the vortex eigenfrequency is changed to higher (lower) values with increasing Oersted field (OH) strength associated with the out-of-plane dc current for the vortex chirality parallel (antiparallel) to the rotation sense of the OH circumferential in-plane orientation. The eigenfrequency shift was found to be linearly proportional to the current density j0 in the linear regime as in ?? D ≃?? j0 / G, where G is the gyrovector constant and is a positive constant, e.g., 1.9?? 10-8 erg/A for a model Permalloy dot of 300 nm diameter and 20 nm thickness. This behavior originates from the sizable contribution of the OH to the effective potential energy of a displaced vortex core in the gyrotropic motion. The present results reveal that D, an intrinsic dynamic characteristic of a given nanodot vortex state, is controllable by changes in both the density and direction of spin-polarized out-of-plane dc currents.open191
Origin of the increased velocities of domain wall motions in soft magnetic thin-film nanostripes beyond the velocity-breakdown regime
It is known that oscillatory domain-wall (DW) motions in soft magnetic
thin-film nanostripes above the Walker critical field lead to a remarkable
reduction in the average DW velocities. In a much-higher-field region beyond
the velocity-breakdown regime, however, the DW velocities have been found to
increase in response to a further increase of the applied field. We report on
the physical origin and detailed mechanism of this unexpected behavior. We
associate the mechanism with the serial dynamic processes of the nucleation of
vortex-antivortex (V-AV) pairs inside the stripe or at its edges, the
non-linear gyrotropic motions of Vs and AVs, and their annihilation process.
The present results imply that a two-dimensional soliton model is required for
adequate interpretation of DW motions in the linear- and oscillatory-DW-motion
regimes as well as in the beyond-velocity-breakdown regime.Comment: 16 pages, 3 figure
Oppositely rotating eigenmodes of spin-polarized current-driven vortex gyrotropic motions in elliptical nanodots
The authors found that there exist two different rotational eigenmodes of oppositely rotating sense in spin-polarized current-driven vortex gyrotropic motions in soft magnetic elliptical nanodots. Simple mathematical expressions were analytically calculated by adopting vortex-core (VC)-rotation-sense- dependent dynamic susceptibility tensors based on the linearized Thiele equation [Phys. Rev. Lett. 30, 230 (1973)]. The numerical calculations of those analytical expressions were confirmed by micromagnetic simulations, revealing that linear-regime steady-state VC motions driven by any polarized oscillating currents can be interpreted simply by the superposition of the clockwise and counterclockwise rotational eigenmodes. The shape of the orbital trajectories of the two eigenmodes is determined only by the lateral dimension of elliptical dots. Additionally, the orbital radii and phases of the two eigenmodes' VC motions were found to markedly vary with the frequency of applied currents, particularly across the vortex eigenfrequency and according to the vortex polarization, which results in overall VC motions driven by any polarized oscillating currents.open8
Total Reflection and Negative Refraction of Dipole-Exchange Spin Waves at Magnetic Interfaces: Micromagnetic Modeling Study
We demonstrated that dipole-exchange spin waves traveling in geometrically
restricted magnetic thin films satisfy the same laws of reflection and
refraction as light waves. Moreover, we found for the first time novel wave
behaviors of dipole-exchange spin waves such as total reflection and negative
refraction. The total reflection in laterally inhomogeneous thin films composed
of two different magnetic materials is associated with the forbidden modes of
refracted dipole-exchange spin waves. The negative refraction occurs at a 90
degree domain-wall magnetic interface that is introduced by a cubic magnetic
anisotropy in the media, through the anisotropic dispersion of dipole-exchange
spin waves.Comment: 13 pages, 5 figure
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