Touch events and human activities for continuous authentication via smartphone.

The security of modern smartphones is related to the combination of Continuous Authentication approaches, Touch events, and Human Activities. The approaches of Continuous Authentication, Touch Events, and Human Activities are silent to the user but are a great source of data for Machine Learning Algorithms. This work aims to develop a method for continuous authentication while the user is sitting and scrolling documents on the smartphone. Touch Events and Smartphone Sensor Features (from the well-known H-MOG Dataset) were used with the addition, for each sensor, of the feature called Signal Vector Magnitude. Several Machine Learning Models have been considered with different experiment setups, 1-class, and 2-class, for evaluation. The results show that the 1-class SVM achieves an accuracy of 98.9% and an F1-score of 99.4%, considering the selected features and the feature Signal Vector Magnitude very significant.

Citing retracted literature: a word of caution.

INTRODUCTION: Inappropriate citation of retracted literature is a common problem in the general medical literature. In 2020, more than 2300 articles were retracted, a dramatic increase from 38 in 2000. By exploring a contemporary series of retractions by one research group, we aimed to evaluate if citations of retracted articles is occurring in the area of regional anesthesiology. METHODS: Using the Scopus database, we examined the full text of all the articles citing research articles coauthored by an anesthesiologist who had multiple articles retracted in 2022. After excluding the research articles citing non-retracted articles authored by the above mentioned anesthesiologist, we included in our analysis all the articles containing a retracted citation and published after the retraction notice. RESULTS: The search was performed on October 30, 2022, retrieving a total of 121 articles citing the researcher's work. Among the retrieved articles, 53 correctly cited non-retracted research and 37 were published before the retraction notice. Among the 31 remaining articles, 42 retracted research papers were cited. Twenty-five of the retracted articles were cited in the Discussion section of the manuscripts, 15 in the Introduction section, 1 in the Methods section (description of a technique), and one was cited in a review. No manuscript used the flawed data to calculate the sample size. DISCUSSION: In this contemporary example from the regional anesthesia literature, we identified that citation of retracted work remains a common phenomenon.

Full-wave feasibility study of anti-radar diagnostic of magnetic field based on O-X mode conversion and oblique reflectometry imaging.

An innovative millimeter wave diagnostic is proposed to measure the local magnetic field and edge current as a function of the minor radius in the tokamak pedestal region. The idea is to identify the direction of minimum reflectivity at the O-mode cutoff layer. Correspondingly, the transmissivity due to O-X mode conversion is maximum. That direction, and the angular map of reflectivity around it, contains information on the magnetic field vector B at the cutoff layer. Probing the plasma with different wave frequencies provides the radial profile of B. Full-wave finite-element simulations are presented here in 2D slab geometry. Modeling confirms the existence of a minimum in reflectivity that depends on the magnetic field at the cutoff, as expected from mode conversion physics, giving confidence in the feasibility of the diagnostic. The proposed reflectometric approach is expected to yield superior signal-to-noise ratio and to access wider ranges of density and magnetic field, compared with related radiometric techniques that require the plasma to emit electron Bernstein waves. Due to computational limitations, frequencies of 10-20 GHz were considered in this initial study. Frequencies above the edge electron-cyclotron frequency (f > 28 GHz here) would be preferable for the experiment, because the upper hybrid resonance and right cutoff would lie in the plasma, and would help separate the O-mode of interest from spurious X-waves.

Reverse chromatic aberration and its numerical optimization in a metamaterial lens.

In planar metamaterial lenses, the focal point moves with the frequency. Here it is shown numerically that this movement can be controlled by properly engineering the dimensions of the metamaterial-based phase shifters that constitute the lens. In particular, such lenses can be designed to exhibit unusual chromatic aberration with the focal length increasing, rather than decreasing, with the frequency. It is proposed that such an artificial "reverse" chromatic aberration may optimize the transverse resolution of millimeter wave diagnostics of plasmas and be useful in compensating for the natural "ordinary" chromatic aberration of other components in an optical system. More generally, optimized chromatic aberration will allow for simultaneous focusing of several objects located at different distances and emitting or reflecting at different frequencies.

A spinning mirror for fast angular scans of EBW emission for magnetic pitch profile measurements.

A tilted spinning mirror rapidly steers the line of sight of the electron Bernstein wave (EBW) emission radiometer at the Mega-Amp Spherical Tokamak (MAST). In order to resist high mechanical stresses at rotation speeds of up to 12,000 rpm and to avoid eddy current induced magnetic braking, the mirror consists of a glass-reinforced nylon substrate of a special self-balanced design, coated with a reflecting layer. By completing an angular scan every 2.5-10 ms, it allows one to characterize with good time resolution the Bernstein-extraordinary-ordinary mode-conversion efficiency as a function of the view angles. Angular maps of conversion efficiency are directly related to the magnetic pitch angle at the cutoff layer for the ordinary mode. Hence, measurements at various frequencies provide the safety factor profile at the plasma edge. Initial measurements and indications of the feasibility of the diagnostic are presented. Moreover, angular scans indicate the best launch conditions for EBW heating.