Channel State Information-Free Location-Privacy Enhancement: Delay-Angle Information Spoofing

In this paper, a delay-angle information spoofing (DAIS) strategy is proposed for location-privacy enhancement. By shifting the location-relevant delays and angles without the aid of channel state information (CSI) at the transmitter, the eavesdropper is obfuscated by a physical location that is distinct from the true one. A precoder is designed to preserve location-privacy while the legitimate localizer can remove the obfuscation with the securely shared information. Then, a lower bound on the localization error is derived via the analysis of the geometric mismatch caused by DAIS, validating the enhanced location-privacy. The statistical hardness for the estimation of the shared information is also investigated to assess the robustness to the potential leakage of the designed precoder structure. Numerical comparisons show that the proposed DAIS scheme results in more than 15 dB performance degradation for the illegitimate localizer at high signal-to-noise ratios, which is comparable to a recently proposed CSI-free location-privacy enhancement strategy and is less sensitive to the precoder structure leakage than the prior approach

Guaranteed Private Communication with Secret Block Structure

A novel private communication framework is proposed where privacy is induced by transmitting over channel instances of linear inverse problems that are identifiable to the legitimate receiver, but unidentifiable to an eavesdropper. The gap in identifiability is created in the framework by leveraging secret knowledge between the transmitter and the legitimate receiver. Specifically, the case where the legitimate receiver harnesses a secret block structure to decode a transmitted block-sparse message from underdetermined linear measurements in conditions where classical compressed sensing would provably fail is examined. The applicability of the proposed scheme to practical multiple access wireless communication systems is discussed. The protocol's privacy is studied under a single transmission, and under multiple transmissions without refreshing the secret block structure. It is shown that, under a specific scaling of the channel dimensions and transmission parameters, the eavesdropper can attempt to overhear the block structure from the fourth-order moments of the channel output. Computation of a statistical lower bound, suggests that the proposed fourth-order moment secret block estimation strategy is near optimal. The performance of a spectral clustering algorithm is studied to that end, defining scaling laws on the lifespan of the secret key before the communication is compromised. Finally, numerical experiments corroborating the theoretical findings are conducted.Comment: arXiv admin note: text overlap with arXiv:2110.0434

Joint Localization and Orientation Estimation in Millimeter-Wave MIMO OFDM Systems via Atomic Norm Minimization

Herein, an atomic norm based method for accurately estimating the location and orientation of a target from millimeter-wave multi-input-multi-output (MIMO) orthogonal frequency-division multiplexing (OFDM) signals is presented. A novel virtual channel matrix is introduced and an algorithm to extract localization-relevant channel parameters from its atomic norm decomposition is designed. Then, based on the extended invariance principle, a weighted least squares problem is proposed to accurately recover the location and orientation using both line-of-sight and non-line-of-sight channel information. The conditions for the optimality and uniqueness of the estimate and theoretical guarantees for the estimation error are characterized for the noiseless and the noisy scenarios. Theoretical results are confirmed via simulation. Numerical results investigate the robustness of the proposed algorithm to incorrect model order selection or synchronization error, and highlight performance improvements over a prior method. The resultant performance nearly achieves the Cramer-Rao lower bound on the estimation error.Comment: arXiv admin note: text overlap with arXiv:2110.0440

Weight-based Channel-model Matrix Framework provides a reasonable solution for EEG-based cross-dataset emotion recognition

Cross-dataset emotion recognition as an extremely challenging task in the field of EEG-based affective computing is influenced by many factors, which makes the universal models yield unsatisfactory results. Facing the situation that lacks EEG information decoding research, we first analyzed the impact of different EEG information(individual, session, emotion and trial) for emotion recognition by sample space visualization, sample aggregation phenomena quantification, and energy pattern analysis on five public datasets. Based on these phenomena and patterns, we provided the processing methods and interpretable work of various EEG differences. Through the analysis of emotional feature distribution patterns, the Individual Emotional Feature Distribution Difference(IEFDD) was found, which was also considered as the main factor of the stability for emotion recognition. After analyzing the limitations of traditional modeling approach suffering from IEFDD, the Weight-based Channel-model Matrix Framework(WCMF) was proposed. To reasonably characterize emotional feature distribution patterns, four weight extraction methods were designed, and the optimal was the correction T-test(CT) weight extraction method. Finally, the performance of WCMF was validated on cross-dataset tasks in two kinds of experiments that simulated different practical scenarios, and the results showed that WCMF had more stable and better emotion recognition ability.Comment: 18 pages, 12 figures, 8 table

Growth and Optical Properties of the Whole System of Li(Mn1−x_{1-x},Nix_{x})PO4_{4} (0 ≤ x ≤ 0.5) Single Crystals

A series of single crystals of Li(Mn$_{1-x}$,Ni$_{x}$)PO$_{4}$ (x = 0.00, 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.08, 0.10, 0.15, 0.20, and 0.50) have been grown to large sizes up to 5 mm in diameter and 120 mm in length using the floating zone method for the first time. The comprehensive characterizations of the as-grown crystals were performed before further physical property measurements. The composition of the grown crystals was determined by energy-dispersive X-ray spectroscopy. The crystal structures were characterized by the X-ray powder diffraction method with a GSAS fitting for structural refinement, which reveals a high phase purity of the as-obtained crystals. The polarized microscopic images and Laue patterns prove the excellent quality of the single crystals. Oriented cuboids with sizes of 2.7 × 3.8 × 2.1 mm$3{1-x}$ along the a, b, and c crystalline directions were cut and polished for further anisotropic magnetic and transparent measurements. We also first proposed a new potential application in the non-linear optical (NLO) and laser generation application for LiMPO$_{4}$ (M = transition metal) materials. The optical and laser properties, such as the absorption spectra and the second harmonic generation (SHG), have been investigated and have furthermore confirmed the good quality of the as-grown single crystals

The Electronic Structural and Defect-Induced Absorption Properties of a Ca2_{2}B10_{10}O14_{14}F6_{6} Crystal

Comprehensive ab initio electronic structure calculations were performed for a newly developed deep-ultraviolet (DUV) non-linear optical (NLO) crystal Ca$_{2}$B$_{10}$O$_{14}$F$_{6}$ (CBOF) using the first principle method. Fifteen point defects including interstitial, vacancy, antisite, Frenkel, and Schottky of Ca, O, F, and B atoms in CBOF were thoroughly investigated as well as their effects on the optical absorption properties. Their formation energies and the equilibrium concentrations were also calculated by ab initio total energy calculations. The growth morphology was quantitatively analyzed using the Hartman–Perdok approach. The formation energy of interstitial F (Fi) and antisite defect O$_{F}$ were calculated to be approximately 0.33 eV and 0.83 eV, suggesting that they might be the dominant defects in the CBOF material. The absorption centers might be induced by the O and F vacancies (V$_{F}$, V$_{O}$), interstitial B and O (O$_{i}$, B$_{i}$), and the antisite defect O substitute of F (O$_{F}$), which might be responsible for lowering the damage threshold of CBOF. The ionic conductivity might be increased by the Ca vacancy (V$_{ca}$), and, therefore, the laser-induced damage threshold decreases

The Mechanism of ATP-Dependent Allosteric Protection of Akt Kinase Phosphorylation

SummaryKinases use ATP to phosphorylate substrates; recent findings underscore the additional regulatory roles of ATP. Here, we propose a mechanism for allosteric regulation of Akt1 kinase phosphorylation by ATP. Our 4.7-μs molecular dynamics simulations of Akt1 and its mutants in the ATP/ADP bound/unbound states revealed that ATP occupancy of the ATP-binding site stabilizes the closed conformation, allosterically protecting pT308 by restraining phosphatase access and key interconnected residues on the ATP→pT308 allosteric pathway. Following ATP→ADP hydrolysis, pT308 is exposed and readily dephosphorylated. Site-directed mutagenesis validated these predictions and indicated that the mutations do not impair PDK1 and PP2A phosphatase recruitment. We further probed the function of residues around pT308 at the atomic level, and predicted and experimentally confirmed that Akt1H194R/R273H double mutant rescues pathology-related Akt1R273H. Analysis of classical Akt homologs suggests that this mechanism can provide a general model of allosteric kinase regulation by ATP; as such, it offers a potential avenue for allosteric drug discovery

Exercise improves mental health status of young adults via attenuating inflammation factors but modalities matter

IntroductionThe mental health of young adults is a global public health challenge. Numerous studies have demonstrated that exercise benefits mental health. However, it is still unclear which exercise mode is optimal for protecting mental health and its association with the immune system. This study aimed to compare the intervention effect of high-intensity interval training (HIIT) and moderate-to-vigorous intensity continuous training (MVCT) on mental health and assess the underlying mechanism of exercise interventions to improve the immune system, which facilitated the mental health status.MethodsThis is a double-blinded RCT study conducted from October 13, 2020 to January 25, 2021 (ClinicalTrials.gov identifier: NCT04830059). Ninety-three participants who met the inclusion criteria were randomized into the HIIT (N = 33), MVCT (N = 32), and control groups (N = 28) with a mean age of 25.26 (SD = 2.21), and 43% of males enrolled in the study. Professional coaches guided participants in HIIT and MVCT groups to perform 40 min of exercise training three times a week for 12-week while those in the control group received 1 h of health education twice a week. Questionnaires related to mental health status and blood samples of inflammatory factors, including immunoglobulin A (IgA), immunoglobulin M (IgM), albumin (Alb), globulin (GLO), lymphocytes (LYM), and lymphocyte percentage (LYM) were assessed before and after the intervention.ResultsWe found that blood inflammation factors increased significantly in the control group during 12 weeks (ΔIgA = 0.16 g/L, ΔIgM = 0.092 g/L, ΔAlb = 2.59 g/L, ΔGlo = 3.08 g/L, ΔLYM = 0.36, and ΔLYM% = 3.72%, p < 0.05), and both MVCT and HIIT intervention could effectively defend the increased inflammatory response compared with the control group (IgA: MVCT β = −0.14, p < 0.001, HIIT β = −0.096, p < 0.05; IgM: MVCT β = −0.12, p < 0.001; HIIT β = −0.068, p < 0.05; Alb: MVCT β = −1.64, p < 0.05, HIIT β = −1.14, p > 0.05; Glo: MVCT β = −3.17, p < 0.001, HIIT β = −2.07, p < 0.01; LYM: MVCT β = −0.34, p < 0.05, HIIT β = −0.35, p < 0.05). However, the MVCT intervention modality was more conducive to enhancing positive affect (β = 0.52, p = 0.018) and well-being (β = 1.08, p = 0.035) than HIIT. Furthermore, decreased IgA, Alb, and Glo were associated with improved mental health.ConclusionBoth 12-week HIIT and MVCT are beneficial to the immune system. The MVCT intervention mode is recommended to prevent mental health problems and attenuate immune inflammation, and the immune system is a potential mechanism that exercises improving mental health.Clinical trial registration[ClinicalTrials.gov], identifier [NCT04830059]