Recent Advances in the Design of Electro-Optic Sensors for Minimally Destructive Microwave Field Probing

In this paper we review recent design methodologies for fully dielectric electro-optic sensors that have applications in non-destructive evaluation (NDE) of devices and materials that radiate, guide, or otherwise may be impacted by microwave fields. In many practical NDE situations, fiber-coupled-sensor configurations are preferred due to their advantages over free-space bulk sensors in terms of optical alignment, spatial resolution, and especially, a low degree of field invasiveness. We propose and review five distinct types of fiber-coupled electro-optic sensor probes. The design guidelines for each probe type and their performances in absolute electric-field measurements are compared and summarized

RT-Sniper: A Low-Overhead Defense Mechanism Pinpointing Cache Side-Channel Attacks

Since cache side-channel attacks have been serious security threats to multi-tenant systems, there have been several studies to protect systems against the attacks. However, the prior studies have limitations in determining only the existence of the attack and/or occupying too many computing resources in runtime. We propose a low-overhead pinpointing solution, called RT-Sniper, to overcome such limitations. RT-Sniper employs a two-level filtering mechanism to minimize performance overhead. It first monitors hardware events per core and isolates a suspected core to run a malicious process. Then among the processes running on the selected core, RT-Sniper pinpoints a malicious process through a per-process monitoring approach. With the core-level filtering, RT-Sniper has an advantage in overhead compared to the previous works. We evaluate RT-Sniper against Flush+Reload and Prime+Probe attacks running SPEC2017, LMBench, and PARSEC benchmarks on multi-core systems. Our evaluation demonstrates that the performance overhead by RT-Sniper is negligible (0.3% for single-threaded applications and 2.05% for multi-threaded applications). Compared to the previous defense solutions against cache side-channel attacks, RT-Sniper exhibits better detection performance with lower performance overhead

Nontrivial torque generation by orbital angular momentum injection in ferromagnetic-metal/ Cu / Al 2 O 3 trilayers

Efficient spin/charge interconversion is desired to develop innovative spin-based devices. So far, the interconversion has been performed by using heavy atomic elements, strong spin-orbit interaction of which realizes the interconversion through the spin Hall effect and the Edelstein effect. We demonstrate highly efficient charge-to-spin conversion in a ferromagnetic metal/Cu/Al2O3 trilayers, which do not contain any heavy element. The resulting spin torque efficiency is higher than those of conventional spin Hall and Rashba systems consisting of heavy elements such as Pt and Bi. Our experimental results qualitatively deviate from typical behaviors arising from spin transport. However, they are surprisingly consistent with the behaviors arising from the orbital transport. Our results thus demonstrate a new direction for efficient charge-to-spin conversion through the orbital transport

The Effects of Exergaming on Attention in Children With Attention Deficit/Hyperactivity Disorder: Randomized Controlled Trial

BackgroundDespite growing evidence showing the effects of exercise and cognitive trainings on enhancing attention, little is known about the combined effects of exergame on attention in children with attention deficit/hyperactivity disorder (ADHD). Exergame, a form of exercise using a video game, has both cognitive stimulation and physical activity components and has been shown to improve cognitive function in children. ObjectiveThe purpose of this study was to investigate the effect of exergaming on attention and to compare the effect induced by exergaming with the effect of aerobic exercise on attention in children with ADHD. MethodsIn all, 30 children with ADHD, aged 8-12 years, were randomly divided into an exergaming group (EXG; n=16) or a bicycle exercise group (BEG; n=14). Before and after the 4-week intervention, the Frankfurter Aufmerksamkeits-Inventar (FAIR; Frankfurt Attention Inventory) test was administrated, and event-related potentials during the Go/No-go task was measured to assess attention. ResultsAfter intervention, both the EXG and BEG had significantly increased selective attention and continuous attention (all P<.001), as well as self-control on the FAIR test (EXG: P=.02 and BEG: P=.005). Similarly, both the EXG and BEG had significantly reduced response time on the Go/No-go test (all P<.001). For the Go response, the N2 amplitude (frontocentral maximal negativity) was significantly increased in Fz (midfrontal line) in the EXG (P=.003) but was not changed in the BEG (P=.97). Importantly, the N2 amplitude in Fz was significantly greater in the EXG compared to the BEG (Go: P=.001 and No-go: P=.008). ConclusionsExergaming has the comparable effects to bicycle exercise to enhance attention in children with ADHD, suggesting that exergaming can be used as an alternative treatment for children with ADHD. Trial RegistrationClinical Research Information Service KCT0008239; https://tinyurl.com/57e4jtn

Sulfur-Doped Carbon Nanotemplates for Sodium Metal Anodes

Sodium metal is a good candidate as an anode for a large-scale energy storage device because of the abundance of sodium resources and its high theoretical capacity (∼1166 mA h g^–1) in a low redox potential (−2.71 V versus the standard hydrogen electrode). In this study, we report effects of sulfur doping on highly efficient macroporous catalytic carbon nanotemplates (MC-CNTs) for a metal anode. MC-CNTs resulted in reversible and stable sodium metal deposition/stripping cycling over ∼200 cycles, with average Coulombic efficiency (CE) of ∼99.7%. After heat treatment with elemental sulfur, the sulfur-doped MC-CNTs (S-MC-CNTs) showed significantly improved cycling performances over 2400 cycles, with average CEs of ∼99.8%. In addition, very small nucleation overpotentials from ∼6 to ∼14 mV were achieved at current densities from 0.5 to 8 mA cm^–2, indicating highly efficient catalytic effects for sodium metal nucleation and high rate performances of S-MC-CNTs. These results provide insight regarding a simple but feasible strategy based on bioabundant precursors and an easy process to design a high-performance metal anode

Oxide layer dependent orbital torque efficiency in ferromagnet/Cu/oxide heterostructures

The utilization of orbital transport provides a versatile and efficient spin manipulation mechanism. As interest in orbital-mediated spin manipulation grows, we face a new issue to identify the underlying physics that determines the efficiency of orbital torque (OT). In this study, we systematically investigate the variation of OT governed by orbital Rashba-Edelstein effect at the Cu/oxide interface, as we change the oxide material. We find that OT varies by a factor of ∼2, depending on the oxide. Our results suggest that the active electronic interatomic interaction (hopping) between Cu and the oxygen atom is critical in determining OT. This also gives us an idea of what type of material factors is critical in forming a chiral orbital Rashba texture at the Cu/oxide interface