Compensation of Time-Varying Delay in Networked Control System over Wi-Fi Network

In this study, we design a state predictor-based output feedback controller that compensates for unavoidable time-varying network delays in networked control systems (NCSs) over Wi-Fi networks. We model time-varying network delays as timevarying input delays of NCSs over Wi-Fi networks. The designed controller consists of a linear quadratic regulator (LQR), a full-order observer, and a time-varying stepahead state predictor. The state predictor plays a key role in compensating for the time-varying input delay by providing the LQR with an estimation of future states ahead by the current network delay time. The time-varying network delays are acquired in real time by measuring the time differences between sent and received control data packets. We verify the stability and compensation performance of the designed controller by performing extensive experiments for an NCS in which a rotary inverted pendulum is controlled over Wi-Fi networks

Self-assembled arrays of zinc oxide nanoparticles from monolayer films of diblock copolymer micelles

A hexagonal array of optically active ZnO nanoparticles was synthesized in situ on the solid substrate by utilizing a single-layered film of diblock copolymer micelles as a nanostructured template

Comparison of infarct-related artery vs multivessel revascularization in ST-segment elevation myocardial infarction with multivessel disease: Analysis from Korea Acute Myocardial Infarction Registry

Background: Many ST-segment elevation myocardial infarction (STEMI) patients have multivessel disease. There is still controversy in treatment strategy in STEMI patients with multivessel disease. We compared clinical outcomes of multivessel revascularization with infarct- related artery (IRA) revascularization in STEMI patients. Methods: The 1,644 STEMI patients with multivessel disease (1,106 in IRA group, 538 in multivessel group) who were received primary percutaneous coronary intervention (PCI) were analyzed from a nationwide Korea Acute Myocardial Infarction Registry. Primary endpoint was 12-month major adverse cardiac events (MACE, defined as death, myocardial infarction, and repeated revascularization). Secondary endpoints were 1-month MACE and each component, stent thrombosis during 12 month follow-up, and each components of the 12-month MACE. Results: There were more patients with unfavorable baseline conditions in IRA group. 12-month MACE occurred in 165 (14.9%) patients in IRA group, 81 (15.1%) patients in multivessel group (p = 0.953). There were no statistical significance in the rate of 1-month MACE, each components of 1-month MACE, and stent thrombosis during 12 month follow-up. Each components of 12-month MACE were occurred similarly in both groups except for target lesion revascularization (2.4% in IRA group vs 5.9% in multivessel group, p < 0.0001). After adjusting for confounding factors, multivessel revascularization was not associated with reduced 12-month MACE (OR 1.096, 95% CI 0.676&#8211;1.775, p = 0.711). Conclusions: There were no significant differences in clinical outcomes between both groups except for high risk of target lesion revascularization in multivessel revascularization group

Chiral electroluminescence from thin-film perovskite metacavities

Chiral light sources realized in ultracompact device platforms are highly desirable for various applications. Among active media employed for thin-film emission devices, lead-halide perovskites have been extensively studied for photoluminescence due to their exceptional properties. However, up to date, there have been no demonstrations of chiral electroluminescence with a substantial degree of circular polarization (DCP), being critical for the development of practical devices. Here, we propose a new concept of chiral light sources based on a thin-film perovskite metacavity and experimentally demonstrate chiral electroluminescence with DCP approaching 0.38. We design a metacavity created by a metal and a dielectric metasurface supporting photonic eigenstates with close-to-maximum chiral response. Chiral cavity modes facilitate asymmetric electroluminescence of pairs of left and right circularly polarized waves propagating in the opposite oblique directions. The proposed ultracompact light sources are especially advantageous for many applications requiring chiral light beams of both helicities.Comment: 20 pages, 4 figure

A magnetically actuated microrobot for targeted neural cell delivery and selective connection of neural networks

There has been a great deal of interest in the development of technologies for actively manipulating neural networks in vitro, providing natural but simplified environments in a highly reproducible manner in which to study brain function and related diseases. Platforms for these in vitro neural networks require precise and selective neural connections at the target location, with minimal external influences, and measurement of neural activity to determine how neurons communicate. Here, we report a neuron-loaded microrobot for selective connection of neural networks via precise delivery to a gap between two neural clusters by an external magnetic field. In addition, the extracellular action potential was propagated from one cluster to the other through the neurons on the microrobot. The proposed technique shows the potential for use in experiments to understand how neurons communicate in the neural network by actively connecting neural clusters. Copyright © 2020 The Authors, some rights reserved.1

Temporary formation of highly conducting domain walls for non-destructive read-out of ferroelectric domain-wall resistance switching memories

Funding: Strategic Priority Research Program of the Chinese Academy of Sciences (grant number XDB07030200) (JFS).Erasable conductive domain walls in insulating ferroelectric thin films can be used for non-destructive electrical read-out of the polarization states in ferroelectric memories. Still, the domain-wall currents extracted by these devices have not yet reached the intensity and stability required to drive read-out circuits operating at high speeds. This study demonstrated non-destructive read-out of digital data stored using specific domain-wall configurations in epitaxial BiFeO3 thin films formed in mesa-geometry structures. Partially switched domains, which enable the formation of conductive walls during the read operation, spontaneously retract when the read voltage is removed, reducing the accumulation of mobile defects at the domain walls and potentially improving the device stability. Three-terminal memory devices produced 14 nA read currents at an operating voltage of 5 V, and operated up to T = 85 °C. The gap length can also be smaller than the film thickness, allowing the realization of ferroelectric memories with device dimensions far below 100 nm.PostprintPostprintPeer reviewe

Marked Suppression of Ghrelin Concentration by Insulin in Prader-Willi Syndrome

The plasma ghrelin has been reported to be elevated in Prader-Willi syndrome (PWS) and modulated by insulin. It was hypothesized that insulin might have a more pronounced effect on reducing plasma ghrelin in PWS patients, which would influence appetite. This study investigated the degree of ghrelin suppression using an euglycemic hyperinsulinemic clamp in children with PWS (n=6) and normal children (n=6). After a 90-min infusion of insulin, the plasma ghrelin level decreased from a basal value of 0.86±0.15 to 0.58±0.12 ng/mL in the controls, and from 2.38±0.76 to 1.12±0.29 ng/mL in children with PWS (p=0.011). The area under the curve below the baseline level over the 90 min insulin infusion was larger in children with PWS than in controls (-92.82±44.4 vs. -10.41±2.87 ng/mL/90 min) (p=0.011). The insulin sensitivity measured as the glucose infusion rate at steady state was similar in the two groups (p=0.088). The decrease in the ghrelin levels in response to insulin was more pronounced in the children with PWS than in the controls. However, the level of ghrelin was always higher in the children with PWS during the clamp study. This suggests that even though insulin sensitivity to ghrelin is well maintained, an increase in the baseline ghrelin levels is characteristic of PWS