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

Effect of Ultrasonic Pretreatment on the Gel Properties and Structure of Flaxseed Gum-Soybean Protein Isolate Composite Gels

Objective: This study aimed to investigate the impact of different ultrasonic power and time pretreatments on the structures and gel properties of the flaxseed gum and soybean protein isolate composite gel induced by TG enzyme. Methods: The structural characteristics, molecular conformation, and micro-network structures of the composite gel under varying ultrasonic conditions were analyzed using a texture analyzer, laser particle size meter, circular dichroism (CD), fluorescence spectrum, and scanning electron microscope (SEM). Results: The 50% power ultrasound pretreatment for 10 min could significantly improve the hardness, adhesiveness, chewiness, cohesiveness and water-holding property of the composite gel, and reduce its adhesiveness. After 50% power ultrasound pretreatment for 10 min, the α-helix and β-turn content of composite gel proteins decreased, and the content of β-folding and irregular curls increased, and the fluorescence intensity increased, which was conducive to the improvement of the functional properties of the gel. The microstructure of the composite gel became ordered from disorder, the network density increased, the pore diameter became smaller, and the pore wall was thickened. While after increasing the ultrasound power to 80%, the gel properties fluctuated only slightly and the microstructure was destroyed. Conclusion: 50% power ultrasound pretreatment for 10 min can significantly improve the gel properties and network structure of TG enzyme cross-linked flaxseed gum-soybean protein isolate composite

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

Analyse statistique et modélisation d'antennes souples ou flexibles dans des conditions fluctuantes

With the massive deployment of flexible electronics in the context of Internet of Things (IoT) and wireless body area networks (WBANs), the demand for soft or flexible antennas is substantially growing. Unlike traditional nondeformable or clearly isolated antennas whose characteristics are deterministic, soft/flexible antennas, especially whenthey are implemented in fluctuating conditions, are subject to various types of variability by essence random: geometric deformations, variations in the material properties, interactions with the surrounding environment (e.g. the human body), etc. These random uncertainties can significantly disturb the in situ performance of antennas and must be taken into account quantitatively. The characterization of these random effects cannot be effectively achieved using the conventional "electromagnetic simulation - prototyping - measurement" approach because of its very high cost (for each of these steps). In this context, surrogate models which can effectively predict these random effects with good precision are extremely useful. This dissertation focuses on the investigation of efficient methodologies dedicated to the construction of surrogate models for antennas undergoing random uncertainties. Two main objectives are targeted. On the one hand, describe quantitatively and parsimoniously the overall behavior of the antennas, that is to say, the complete radiated far-field (FF) as well as the reflection coefficient. On the other hand, propose efficient, reliable and versatile methodologies for the extraction of antenna models from a limited number of pre-evaluations. In particular, a statistical methodology based on polynomial chaos has been proposed and its effectiveness has been demonstrated by applying it firstly to a canonical antenna undergoing various types of deformations, then in a more realistic application framework, to an antenna printed on a fabric substrate. The benefit of the surrogate models thus developed is to have access to the responses of the "random antennas" at a very low calculation cost. From the application point of view, such surrogate models can be used in various types of higher-level analysis such as joint antenna/channel modeling, radio links analysis, antenna plugged-in asymptotic simulators (e.g. ray launching or tracing), Multi-Input & Multi-Output (MIMO) systems characterization, or beamforming.Avec le déploiement massif des électroniques flexibles dans le contexte de l’Internet des objets et des réseaux corporels sans fil, la demande d’antennes souples ou flexibles est amenée à se développer. Contrairement aux antennes traditionnelles non déformables ou clairement isolées dont les caractéristiques sont déterministes, les antennes souples/flexibles, en particulier lorsqu’elles sont mises en oeuvre dans des conditions fluctuantes, sont sujettes à divers types de variabilité par essence aléatoires : déformations géométriques, variations dans les propriétés des matériaux, interactions avec l’environnement proche (par ex. le corps humain), etc. Ces incertitudes aléatoires peuvent perturber significativement les performances in situ des antennes et doivent être prises en compte quantitativement. La caractérisation de ces effets aléatoires ne peut être efficacement réalisée au moyen de l’approche conventionnelle de “simulation électromagnétique − prototypage – mesure” en raison de son coût très élevé (pour chacune de ces étapes). Dans ce contexte, des modèles de substitution qui permettent de prédire efficacement ces effets aléatoires avec une bonne précision sont excessivement utiles. Ce mémoire de thèse se concentre sur l'étude des méthodologies efficaces dédiées à la construction des modèles de substitution pour les antennes subissant des déformations aléatoires. Deux objectifs principaux sont visés. D'une part, décrire quantitativement et parcimonieusement le comportement complet des antennes, c'est-à-dire le champ lointain rayonné ainsi que le coefficient de réflexion. D'autre part, proposer des méthodologies efficaces, fiables et polyvalentes pour l'extraction de modèles d'antennes à partir d'un nombre limité de pré-évaluations. Notamment, une méthodologie statistique fondée sur le chaos polynomial a été proposée et son efficacité a été démontrée en l’appliquant tout d’abord à une antenne canonique subissant divers types de déformations, puis à une antenne imprimée sur substrat en tissu dans un cadre applicatif plus réaliste. L’intérêt des modèles de substitution ainsi développés est de pouvoir disposer de réponses « d’antennes aléatoires » pour un très faible coût de calcul. Du point de vue applicatif, cela permet de les utiliser dans divers types d'analyses de niveaux supérieurs telles que la modélisation conjointe antenne/canal, puis celle du lien radio, l’intégration des antennes dans les simulateurs asymptotiques (lancé ou tracé de rayons), la caractérisation des systèmes Multi-entrée & Multi-sortie, ou la formation de faisceaux

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