Adaptive fuzzy fixed time formation control of state constrained nonlinear multi-agent systems against FDI attacks

In this manuscript, based on nonlinear multi-agent systems (MASs) with full state constraints and considering security control problem under false data injection (FDI) attacks, the fixed-time formation control (FTFC) protocol was designed, which can ensure that all agents follow the required protocol within a fixed time. Fuzzy logic system (FLS) was used to compensate and approximate the uncertain function, which improved safety and robustness of the formation process. Finally, the fixed-time theory and Lyapunov stability theory were addressed to prove the effectiveness of the proposed method, and simulation examples verified the effectiveness of the theory

A novel 24 GHz circularly polarised metasurface rectenna

A novel 24 GHz circularly polarised metasurface rectenna for wireless power transmission is designed in this study. Based on experimental measurements and retro‐simulation, an effective approach is proposed to extract the parasitic parameters of a Schottky diode. A highly efficient millimetre wave rectifier with a measured efficiency of 63% is constructed based on the exact equivalent circuit parameters of a diode. A circularly polarised metasurface antenna is adopted as the receiving antenna, and the gain is enhanced by introducing metal vias around the metasurface. The antenna and the rectifier are connected directly via a microstrip line. Measurements show that the metasurface antenna has a gain of 11.3 dBic and an axial ratio of 2.5 dB at 24 GHz. The measured conversion efficiency of the rectenna reaches 63% at 300 Ω load when the input power is 15.2 dBm. The rectenna has the advantages of low profile, which can be conformal to the electrical equipment

Polarization-Insensitive Metasurface for Harvesting Electromagnetic Energy with High Efficiency and Frequency Stability over Wide Range of Incidence Angles

In this paper, a polarization-insensitive metasurface, harvesting electromagnetic (EM) energy with high efficiency and frequency stability over a wide range of incidence angles, is proposed. The previously reported metasurfaces suffer from their maximum efficiencies shifting with the frequency when the incidence angle increases. By introducing a square-shaped metal via ring around the elements, the mutual coupling among adjacent cells is reduced so that the proposed metasurface can maintain maximum efficiency at the fixed operation frequency over a wide range of incidence angles. Furthermore, with one single harvesting via in the proper position for the connection of a harvesting load, the metasurface can collect EM energy effectively with both transverse electric (TE) and transverse magnetic (TM) polarizations in one single harvesting load. Compared with the reported metasurfaces, this proposed metasurface has a higher efficiency and fixed operation frequency within a wide incidence range. The energy distribution, harvesting efficiency, and surface current are simulated to investigate the operation mechanism of the proposed metasurface. The simulation results show that the maximum harvesting efficiency is 91% at 5.8 GHz for both TE and TM polarizations at the normal incidence. When the incident angle increases to 75°, the maximum efficiency is achieved at 5.79 GHz (0.19% shift), and the maximum efficiencies of TM and TE polarizations are 91% and 68%, respectively. A 5 × 5 array is fabricated and tested. The experimental results are in good agreement with the simulated ones

Cathepsins and cancer risk: a Mendelian randomization study

BackgroundPrevious observational epidemiological studies reported an association between cathepsins and cancer, however, a causal relationship is uncertain. This study evaluated the causal relationship between cathepsins and cancer using Mendelian randomization (MR) analysis.MethodsWe used publicly available genome-wide association study (GWAS) data for bidirectional MR analysis. Inverse variance weighting (IVW) was used as the primary MR method of MR analysis.ResultsAfter correction for the False Discovery Rate (FDR), two cathepsins were found to be significantly associated with cancer risk: cathepsin H (CTSH) levels increased the risk of lung cancer (OR = 1.070, 95% CI = 1.027–1.114, P = 0.001, PFDR= 0.009), and CTSH levels decreased the risk of basal cell carcinoma (OR = 0.947, 95% CI = 0.919–0.975, P = 0.0002, PFDR= 0.002). In addition, there was no statistically significant effect of the 20 cancers on the nine cathepsins. Some unadjusted low P-value phenotypes are worth mentioning, including a positive correlation between cathepsin O (CTSO) and breast cancer (OR = 1.012, 95% CI = 1.001–1.025, P = 0.041), cathepsin S (CTSS) and pharyngeal cancer (OR = 1.017, 95% CI = 1.001–1.034, P = 0.043), and CTSS and endometrial cancer (OR = 1.055, 95% CI = 1.012–1.101, P = 0.012); and there was a negative correlation between cathepsin Z and ovarian cancer (CTSZ) (OR = 0.970, 95% CI = 0.949–0.991, P = 0.006), CTSS and prostate cancer (OR = 0.947, 95% CI = 0.902–0.944, P = 0.028), and cathepsin E (CTSE) and pancreatic cancer (OR = 0.963, 95% CI = 0.938–0.990, P = 0.006).ConclusionOur MR analyses showed a causal relationship between cathepsins and cancers and may help provide new insights for further mechanistic and clinical studies of cathepsin-mediated cancer

A biophoton method for identifying the quality states of fresh Chinese herbs

Introduction: The quality of Chinese herbs is the basis for ensuring their safety and efficacy. However, the quality evaluation system is imperfect. In particular, there is a lack of quality evaluation methods for fresh Chinese herbs during growth. The biophoton is a common phenomenon and provides complete information about the interior of the living system, which is consistent with the holistic concept of traditional Chinese medicine. Therefore, we aim to correlate the biophoton characteristics with the quality states to find the biophoton parameters that can characterize the quality states of fresh Chinese herbs.Methods: The biophoton characteristics of motherwort and safflower were measured and characterized by the counts per second (CPS) in the steady state and the initial intensity (I0) and coherent time (T) of delayed luminescence. The active ingredient content was measured by ultra-high-performance liquid chromatography (UPLC). The pigment content of motherwort leaves was measured by UV spectrophotometry. The t-test and correlation analysis were performed on the experimental results.Results: The CPS and I0 of motherwort and I0 of safflower showed a significant downward trend during the growth process, and their active ingredient content showed a trend that increased and then decreased. The CPS, I0, and the content of active ingredients and pigments in a healthy state were significantly higher than those in a poor state, while T showed the opposite results. The CPS and I0 were all significantly and positively correlated with the content of active ingredients and pigments, while the T of motherwort showed the opposite results.Conclusion: It is feasible to identify the quality states of fresh Chinese herbs by using their biophoton characteristics. Both CPS and I0 have better correlations with the quality states and can be considered characteristic parameters of the quality of fresh Chinese herbs

Parametric Modeling of Deformable Antennas Based on the Spherical Modes Expansion Method

A parametric modeling procedure for analyzing the behavior of deformable antennas radiation characteristics is proposed in this article. This procedure is based on the vector spherical modes expansion method and on polynomial fitting of the coefficients. The methodology is applied to a canonical antenna – a bendable dipole – in order to demonstrate its performance. A deterministic model with high accuracy and high data compression rate up to 99.9% is derived.</p

Statistical Modeling of Disturbed Antennas Based on the Polynomial Chaos Expansion

International audienceA new methodology of statistical modeling of the far field (FF) radiated by antennas undergoing random disturbances is presented. Firstly, the radiated FF is transformed into a parsimonious form using the Spherical Modes Expansion Method (SMEM); then a surrogate model relating the parsimonious field with the input random parameters is constructed using the Polynomial Chaos Expansion Method (PCEM). The combination of the SMEM and the PCEM allows to develop a compact and precise model with a minimized experimental design cost. The obtained model is computationally costless for generating statistical samples of disturbed antennas easily usable as surrogate models in various types of analyses. In order to demonstrate its performance , the proposed methodology is validated with a deformable canonical antenna – a dipole undergoing three independent random deformations (stretching, bending and torsion), deriving a compact and precise surrogate model

Stochastic Surrogate Models of Deformable Antennas based on Vector Spherical Harmonics and Polynomial Chaos Expansions: Application to Textile Antennas

International audience<p>A methodology for modeling the Far Field (FF) radiated by antennas subject to random variabilities with surrogate models of high efficiency is presented herein. The FF is expanded onto Vector Spherical Harmonics, then the stochastic variability of their coefficients is quantitatively modeled with the Polynomial Chaos expansion. The accuracy of the surrogate model is guaranteed by a robust and efficient adaptive procedure; “extreme parsimony” of the model is achieved thanks to various “compression” techniques; moreover, the characterization of the antenna’s frequency behavior over a band of interest has been taken into account in the modeling for the first time. The methodology is applied to a practical wearable textile patch antenna designed to cover the 2.4 – 2.5 GHz band and which is subject to five geometric and material random parameters. Specifically, the “Weierstrass” curves crumpling effect is modeled for the first time. Comparison to the full-wave simulations shows that the derived surrogate model predicts the FF with good accuracy and with a speed up factor of 105. Such type of surrogate models could be beneficial not only for antenna design and optimization purpose, but also, e.g., for joint antenna-channel stochastic analyses. </p

An UWB Coplanar Waveguide Fed Integrated IFA Design for Wearable Communications

<p>An UWB CPW-fed Integrated “IFA-like” design is proposed. The new design has a much longer short-ended arm and a much narrower gap between the radiating arms and the coplanar ground plane. The bandwidth increase is achieved thanks to the superposition of multi-resonances induced by the joint effects of a strong coupling between the radiating arms and the ground plane and the excitation of both even and odd CPW modes in the feedline. The design has been tested for two types of substrate, FR4 and denim, for which –10 dB bandwidths of more than 60 % and 87 % are achieved respectively. Body proximity effects are analysed for the denim IIFA by simulation. It shows that the antenna remains working well in the presence of human body thanks to its UWB feature. This extremely simple, lowprofile and easily integrable UWB IIFA-like design can be used for wearable communications (on-body/off-body), supporting multi-standards.</p

Statistical Modeling of the Reflection Coefficient of deformable antennas

<p>A modeling methodology is proposed for characterizing the reflection coefficient S11( f ) of narrow band antennas undergoing random disturbances. Firstly, identification techniques are used to get a parsimonious representation of the S11; then the Polynomial Chaos Expansion (PCE) method is used to characterize quantitatively the influence of random disturbances on the compressed S11. The derived S11 model can be used as efficient surrogate for statistical analysis of antennas’ frequency behavior. We have applied the proposed methodology to two narrow band antennas – a deformable dipole and a textile patch – in order to demonstrate its performance. Models with good accuracy have been derived for both cases.</p