Search

In this article, the impact of polarization force and coupling parameter, along with other plasma parameters, on the nonlinear propagation of dust acoustic (DA) shocks is presented in an unmagnetized collisionless strongly coupled dusty plasma having (α , q) -distributed electrons, Maxwellian ions, and charged dust grains fluid. The Burgers equation with quadratic nonlinearity is derived by implementing the reductive perturbation method and it is hence found that DA shocks exist associated with both positive and negative potentials. However, the nonlinear coefficient of Burgers equation with quadratic nonlinearity approaches zero for the critical values (CVs) of some specific parameters. To report the propagation of DA shocks around the CVs, the Burgers equation with cubic nonlinearity is derived by taking the higher-order power of the implemented method. Additionally, the Burgers equation with quartic nonlinearity is derived, which yields the existence of super-critical values (SCVs) of some specific parameters. As a result, progress in understanding the propagation of DA shocks around CVs as well as SCVs is reported. It is found that the polarization force significantly contributes to modify the nature of shock wave propagation around SCVs. The presented investigation might be beneficial for comprehending and predicting localized electrostatic disturbances in some astrophysical compact objects and cosmic environmental space, particularly in dark-matter halos, stellar polytropes, hadronic matter and quark-gluon plasma, protoneutron stars,etc., and the future experimental studies of the dusty plasma laboratory. [ABSTRACT FROM AUTHOR]

Dye-sensitized solar cell (DSSC) technology could become a low-cost solution for solar energy harvesting if the use of expensive dyes and Pt can be avoided. This work reports the development of a novel nanohybrid based on CuCo2S4 nanorods embedded on sheets of reduced graphene oxide (RGO), which can serve as excellent counter electrode for DSSC showing great promise to replace Pt. The phase structure, morphology, chemical composition, and optical properties were characterized by X-ray diffraction, Scanning electron microscope, High-resolution transmission electron microscope, X-ray photoelectron spectra UV–vis diffuse reflectance spectra (DRS), and Photoluminescence. The produced CE greatly enhances the ternary complex’s charge transfer capabilities, which is evidenced in its efficient reduction of I−/I3 redox shuttles. The maximal photo-to-electron conversion efficiency of the constructed CE (CuCo2S4/rGO) is 7.3%, which is greater than the efficiency of bare CuCo2S4-based DSSC (3.5%). Cyclic voltammetry, electrochemical impedance spectroscopy, and Tafel polarization measurements were used to quantify the electrochemical characteristics of CEs; these methods revealed that the CuCo2S4/rGO CE exhibited higher electrocatalytic activity toward triiodide (I3−) reduction than the CuCo2S4 CE. As shown by the findings, CuCo2S4/rGO hybrid CEs may serve as a high-efficiency, low-cost CE for DSSCs. [ABSTRACT FROM AUTHOR]

This work investigates the nonlinear propagation of dust ion-acoustic (DIA) shock waves (SWs) in a collisionless, four-component, unmagnetized, dusty multi-ion plasma. The four components are considered as the generalized (α , q) -distributed electrons, positively charged Maxwell-Boltzmann distributed light ions, negatively charged inertial heavy ions, and negatively charged stationary dusts. To do so, several nonlinear evolution equations are formulated by implementing the reductive perturbation technique. The appropriate solutions to the obtained equations are provided. This work also reinvestigates the electrostatic DIA SWs in the dusty multi-ion nonextensive plasma because of the misleading information for the nonlinear coefficients and analytical solutions of higher-order Burgers equations (BEs) in Ref. [Eur Phys J Plus (2015) 130: 46, ]. It is found from the electrostatic potential obtained by BE that the rarefactive electrostatic shocks are only supported in the presence of superthermal (0.33 < q < 1 , α = 0) , isothermal (q = 1 , α = 0) , and nonthernal electrons (0 < α < 0.35 , q = 1) , but both compressive and rarefactive shocks are supported in the presence of subthermal (q > 1 , α = 0) electrons. The effects of parameters on the DIA SWs are reported. It is also investigated the nature of electrostatic shocks and double layers around the critical values and at the critical values of any specific plasma parameters described by modified BE and mixed modified BE. The outcomes from this work would be helpful for better understanding the dynamics of DIA SWs in space environments and plasma laboratories. [ABSTRACT FROM AUTHOR]

This research addresses the problems of finite-time boundedness and disturbance rejection for T-S fuzzy networked systems that are vulnerable to actuator faults, linear fractional uncertainties and multiple disturbances through a reliable anti-disturbance control design. In particular, multiple disturbances encompasses two kinds, where the first kind of disturbance is matched, which is produced by fuzzy exogenous systems and the second kind is mismatched disturbance, which is norm-bounded. Moreover, in order to depict the reality more precisely, the actuator faults are taken into account in the system under consideration. In particular, the fuzzy disturbance observer is constructed for closely estimating the matched disturbances. After that, a reliable anti-disturbance controller is designed in accordance with the output of the conceived disturbance observer. Furthermore, the (ξ 1 , ξ 2 , ξ 3) - η dissipative performance is deployed in order to reduce the imprints of mismatched disturbances to the greatest extent feasible. Moreover, by constructing a Lyapunov-Krasovskii functional, a set of adequate criteria in the form of linear matrix inequalities is established, which guarantees that the undertaken system achieves finite-time boundedness. In conclusion, two numerical examples are shown, one of which is a model of a tunnel diode circuit, which reveals the competence and applicability of the suggested control mechanism. [ABSTRACT FROM AUTHOR]

Since there is a wide variety of 2D and nanostructured metal sulfide materials with easily tunable electrical, optical, physical, and chemical properties, they hold great promise for the development of numerous gas-sensing applications. These applications are particularly attractive for gas sensing in environmental monitoring and breath analysis. In this paper, researchers describe a unique approach for making CoS2/graphene nanocomposites using the chemical vapor deposition (CVD) technique. In comparison to other gas sensors based on transition-metal dichalcogenide materials, the proposed device offers the fastest response time for sensing NO2 gas. Using a heterojunction device in chemiresistive mode, we study the gas-sensing response at varying levels of NO2. The NO2 gas sensor device made from the CoS2/G composite showed a maximum sensitivity of 6.11 for 50 ppm at the optimal temperature (100 oC), in comparison to the pure CoS2 (2.1). The stability of the CoS2/G composite-based sensor device was further tested by measuring its response to varying concentrations of NO2 gas. It was also discovered that gas sensors based on CoS2 and CoS2/G had high levels of selectivity and reproducibility. Sensing mechanism study for the CoS2/G composite attributes the greater sensitivity of the sensing device to the heterostructure between graphene and CoS2. [ABSTRACT FROM AUTHOR]

In this work pure CuCr2O4 and Mn-doped CuCr2O4 nanoparticles were prepared using Microwave combustion process. The phase analysis of the prepared samples is investigated using X-Ray Diffraction technique and an decrease in particle size observed from ∼37 to ∼26 nm with rise in Mn doping concentration. Further optical data revealed the presence of multiple Mn-related optical centres. Morphological studies revealed the prepared samples exhibited irregular plate-shaped agglomerates. Furthermore, the antibacterial performance of undoped CuCr2O4 and Mn-doped CuCr2O4 samples are investigated. At 500 °C, the electrical conductivity for the CuCr2O4 and Mn-doped CuCr2O4 samples were found to be 0.98 × 10−2 S/cm and 2.13 × 10−2 S/cm respectively. The activation energy of the pristine CuCr2O4 and Mn-doped CuCr2O4 samples was found to be 0.87 eV and 0.69 eV respectively. [ABSTRACT FROM AUTHOR]

In this work pure CuCr2O4 and Mn-doped CuCr2O4 nanoparticles were prepared using Microwave combustion process. The phase analysis of the prepared samples is investigated using X-Ray Diffraction technique and an decrease in particle size observed from ∼37 to ∼26 nm with rise in Mn doping concentration. Further optical data revealed the presence of multiple Mn-related optical centres. Morphological studies revealed the prepared samples exhibited irregular plate-shaped agglomerates. Furthermore, the antibacterial performance of undoped CuCr2O4 and Mn-doped CuCr2O4 samples are investigated. At 500 °C, the electrical conductivity for the CuCr2O4 and Mn-doped CuCr2O4 samples were found to be 0.98 × 10−2 S/cm and 2.13 × 10−2 S/cm respectively. The activation energy of the pristine CuCr2O4 and Mn-doped CuCr2O4 samples was found to be 0.87 eV and 0.69 eV respectively. [ABSTRACT FROM AUTHOR]

This paper deals with the problem of finite-time dissipative-based distributive non-fragile filter design for a class of discrete-time complex systems subject to randomly occurring multiple delays, dynamic quantization and missing measurements. The main intention of this work is to propose a distributive non-fragile filter that ensures the stochastic finite-time boundedness together with prescribed dissipative performance in the presence of multiple delays. To characterize the random nature of delays, stochastic variables are introduced which satisfy the Bernoulli binary distribution. Moreover, the two factors such as missing measurements and dynamic quantization are implemented in the measurement signal. By employing S-procedure and constructing proper Lyapunov–Krasovskii functional, a set of linear matrix inequality (LMI)-based sufficient conditions that guarantee the stochastic finite-time boundedness with dissipative performance of the augmented filtering error system is obtained. Finally, the efficiency of the proposed distributive non-fragile filter design is proved by presenting three numerical examples including the continuous stirred tank reactor (CSTR) and a quarter-car suspension model. [ABSTRACT FROM AUTHOR]

This study concerned with the synchronization problem over a finite-time domain for a class of fractional-order stochastic neural networks via non-fragile controller with discontinuous activation functions. Specifically, the suggested state feedback controller sequentially cope with non-fragile scheme for gain scheduling process. Notably, the main objective of this work is to obtained the finite-time synchronization criterion for the resulting synchronized error system over finite bound with the developed non-fragile controller. For that, some consignment of sufficient conditions is derived systematically by implementing Lyapunov's indirect method and finite-time stability theory which ensures the finite-time stochastic synchronization of the stipulated neural networks. Later on, the controller gain fluctuations that obeying certain white noise sequels derived from Bernoulli distribution are formulated in terms of linear matrix inequalities. Eventually, the illustrated study are substantiated through two numerical examples and the simulation results manifest the advantage and accuracy of the proposed synchronization criteria. [ABSTRACT FROM AUTHOR]

This paper studies a resilient control-based fault estimation problem for a class of networked control systems subject to jumping parameters and deception attacks. In particular, a fault estimator is developed under an observer-based framework to estimate the faults and system states concurrently, and procure better estimation accuracy. Next, the closed-loop error system is constructed with major factors like gain fluctuations and cyber attacks that may damage the network security. In accordance with the Lyapunov stability approach, a set of adequate criteria in the configuration of linear matrix inequalities is derived to confirm the stochastic boundedness of the resulting system. Further, the considered resilient controller and the observer gain matrices are calculated from the established linear matrix inequality constraints. The validity of the developed schemes and performance of the obtained results is consummated through two numerical examples, which include a high alpha research vehicle model. [ABSTRACT FROM AUTHOR]

Here, we demonstrate the improved NO2 gas-sensing properties based on graphene-decorated NiS2 thin film. The grown NiS2 thin film, graphene was spread over NiS2 thin film by chemical vapour deposition (CVD) method. The formation of several p–n heterojunctions is greatly affected by the current–voltage relation of graphene-decorated NiS2 thin film due to p-type and n-type nature of graphene and NiS2, respectively. Initially with graphene decoration on NiS2 thin film, current decreases in comparison to NiS2 thin film, whereas depositing graphene film on glass substrate, current increases drastically. The NO2 gas sensor device is fabricated and its basic characteristics are systematically investigated. The incorporated graphene improves the NO2 sensing response of 97% with compared to bare NiS2 sensor (29%) at 100 ppm NO2 concentration with a practical detection limit below 0.2 ppm. In addition, the recovery time was shortened to a few seconds and the excellent repeatability. This work may provide a promising and practical method to mass produce room-temperature NO2 gas sensors for real-time environment monitoring due to its simple fabrication process, low cost, and practicality. The high-sensing response of NiS2/graphene is attributed to the formation and modulation of p–n heterojunction at the interface of graphene and NiS2. In addition, the presence of active sites graphene surface also enhances the sensing response. [ABSTRACT FROM AUTHOR]

This paper is concerned with the problem of fault detection filter design for a class of nonlinear Markovian jump systems with incomplete measurements and distributed delay. A unified model is proposed to address the phenomena such as packet losses, signal quantization and sensor saturation. The objective is to design a finite-time dissipative-based fault detection filter such that for all unknown disturbances, the estimation error between the residual signal and the fault is minimized and also to guarantee the stochastic finite-time boundedness of the augmented filtering error system with a prespecified dissipative performance level. By using Lyapunov stability theory along with stochastic analysis techniques, a set of sufficient criterion is established for the existence of desired fault detection filter. Further, the filter gain parameters are obtained by solving the linear matrix inequality-based constraints. Two numerical examples including an inverted pendulum model are presented to illustrate the effectiveness of the proposed filter design algorithm. [ABSTRACT FROM AUTHOR]

In this paper, the design problem of fault detection filter for a class of networked control system subject to Markov jump parameters, randomly occurring uncertainties, sensor faults and packet dropouts by using state feedback control is investigated. The fault detection filter is used as an optimal residual generator that generates the residual signal and also guarantees the sensitivity of residual signal to the faults. To be more specific, a suitable threshold is selected for the residual evaluation function to reduce the error between the sensor faults and the residual signal. Further, by employing a fault detection technique along with output quantization approach, a new set of sufficient conditions is derived to ensure the stochastic stabilization of the addressed system with sensor faults under a predefined H ∞ performance level. Particularly, by constructing Lyapunov–Krasovskii functional and utilizing extended Wirtinger-based single integral inequality, the required sufficient conditions are derived in terms of linear matrix inequalities for getting the required result. At last, two numerical examples including high alpha research vehicle model are presented to demonstrate the usefulness of our developed results. [ABSTRACT FROM AUTHOR]

In VLSI system design, one of the most significant areas of on-going research is high speed with low power system design. Usually the speed of the VLSI circuits like binary adders can be improved by more parallelism but, this more parallelism idea will increase the power consumption and area of the circuit. Therefore there is a trade-off between speed and power/area. A carry select adder is one of the fast binary adders but it consumes more power and area. In this paper, we proposed a low power and area efficient and high speed binary carry select adder (CSLA). The half sum and carry generator (HSCG) of the proposed CSLA is designed with a new methodology, that the HSCG output are estimated using input A and B not with carry-in hence it is faster and results in less area leads to low power consumption. Moreover, the NAND gate based circuit is used to compute the intermediate carries within the block and carry-out of the block which are derived from HSCG output along with carry-in. Similarly, the full sum of the proposed adder is generated from XNOR gate based circuitry by utilizing the intermediate carries of the block. The existing and proposed CSLAs are synthesized with the Synopsys EDA tool using 32 nm CMOS technology. The performance of the existing and proposed designs are analyzed and the results shows that the proposed 64-bit CSLA exhibits average reduction of 43% in power and average of 25% less utilization in terms of area compared to existing design. This proposed CSLA is used in a FIR Filter and obtained significant reduction in ADP and PDP. [ABSTRACT FROM AUTHOR]

The primary purpose of this work was to address the problem of finite-time fault detection filtering for a class of discrete-time Takagi–Sugeno (T–S) fuzzy Markovian jump systems subject to randomly occurring uncertainties, time-varying delay, missing measurements and partly unknown transition probability matrices. Precisely the missing measurement phenomenon in the network environment satisfies the Bernoulli distributed white noise sequences. Firstly a fuzzy rule-dependent filter is constructed for estimating the unmeasured states of the system and the corresponding fault detection problem. Further, based on the filtering problem, the error between residual and fault is minimized with the prescribed strict (Q , S , R) - γ dissipativity performance. Secondly, the sufficient criteria are derived to ensure the filtering error system to be finite-time stochastic bounded. Finally, the applicability and usefulness of the proposed filter design through two numerical examples are verified. [ABSTRACT FROM AUTHOR]

This paper presents travelling wave solutions for the nonlinear time-fractional Gardner and Benjamin–Ono equations via the exp( - Φ (ε)) -expansion approach. Specifically, both the models are studied in the sense of conformable fractional derivative. The obtained travelling wave solutions are structured in rational, trigonometric (periodic solutions) and hyperbolic functions. Further, the investigation of symmetry analysis and nonlinear self-adjointness for the governing equations are discussed. The exact derived solutions could be very significant in elaborating physical aspects of real-world phenomena. We have 2D and 3D illustrations for free choices of the physical parameter to understand the physical explanation of the problems. Moreover, the underlying equations with conformable derivative have been investigated using the new conservation theorem. [ABSTRACT FROM AUTHOR]

In this study, we investigate asymptotic property of the solutions for a class of perturbed stochastic differential equations driven by G-Brownian motion (G-SDEs, in short) by proposing a perturbed G-SDE with small perturbation for the unperturbed G-SDE. We consider the closeness in the 2m-order moments of the solutions of perturbed G-SDEs and the unperturbed G-SDEs. At last, the obtained results are illustrated via a concrete example. [ABSTRACT FROM AUTHOR]

The existence of gain variations in control design often disrupts most of the control system performance. By considering this point, as a first attempt in the literature, a robust non-fragile state feedback control design is proposed in this paper for achieving finite-time consensus in a class of stochastic nonlinear multi-agent systems with randomly occurring uncertainty and randomly occurring nonlinearity. Specifically, the randomness phenomena are characterized with the aid of stochastic variables that satisfy the Bernoulli distribution properties. To design the non-fragile control protocol, the communication graph is chosen to be directed and connected subject to switching topologies. On the basis of the Lyapunov–Krasovskii stability theory and stochastic analysis techniques, a new set of sufficient conditions is established to guarantee that the states of all agents can reach an agreement over a given finite-time period via the proposed non-fragile switched control law. The effectiveness of the designed consensus protocol is demonstrated through an academic example. [ABSTRACT FROM AUTHOR]

In this paper, we investigate the controllability and exponential stability results for a class of nonlinear neutral stochastic functional differential control systems in the presence of infinite delay driven by Rosenblatt process in real separable Hilbert spaces. Firstly, by using stochastic analysis approach, fractional calculus theory and a fixed point technique, we prove the controllability result for the mild solutions of the nonlinear control systems with the condition that the associated linear system is controllable. Secondly, we discuss the exponential stability of mild solutions of the nonlinear neutral stochastic differential systems driven by Rosenblatt process. Finally, an example is presented to illustrate the obtained theory. [ABSTRACT FROM AUTHOR]

This research article aims to analyze the properties and characteristics of the products obtained from slow pyrolysis of wood barks of matured Calophyllum inophyllum (CI) tree. The bio-oil, gas and biochar obtained from the slow pyrolysis carried out at 550 °C in a fixed bed batch type reactor at a heating rate of 30 °C min−1 were characterized by different analytical techniques. Owing to the lofty volatile content of CI biomass (72.61%), it was chosen as the raw material in this current experimental investigation. FT-IR and GC–MS results of bio-oil showed the existence of elevated amount phenol derivatives, oxygenated compounds, acids, esters and furans. The physicochemical properties of the bio-oil sample were tested in accordance with ASTM standards which clearly showed that bio-oil is a highly viscous liquid with lower heating value as compared to that of diesel fuel. The chemical composition of pyrolytic gas was analyzed by using Gas Chromatography which revealed the presence of combustible organic components. The FT-IR results of biochar showed the presence of aromatic and aliphatic hydrocarbons whereas the increased amount of carbon in biochar reveals its potential to be used as solid fuel for commercial purposes. [ABSTRACT FROM AUTHOR]

In this paper, the problem of robust consensus for multi-agent systems affected by external disturbances is discussed. A novel consensus control is developed by using a feedback controller based on disturbance rejection and Smith predictor scheme. Specifically, the disturbance rejection performance of the uncertain multi-agent systems is improved according to the estimation of equivalent-input-disturbance and the effect of time delay in the control system is reduced via Smith predictor scheme by shifting the delay outside the feedback loop. Furthermore, by combining Lyapunov theory, matrix inequality techniques and properties of Kronecker product, a robust feedback controller for each agent is designed such that the desired consensus of the uncertain multi-agent systems affected by external disturbances can be ensured. Finally, to illustrate the validity of the designed control scheme, two numerical examples with simulation results are provided. [ABSTRACT FROM AUTHOR]

In this paper, we propose three novel algorithms such as Novel genetic algorithm complex-valued backpropagation neural network (GA-CVBNN), Novel elegant fuzzy genetic algorithm (EFGA) and elegant fuzzy genetic algorithm-based complex-valued backpropagation neural network (EFGA-CVBNN) for classification of accuracy in datasets. In GA-CVBNN, classical Genetic Algorithm has been used for selecting appropriate initial weights for CVBNN. The EFGA is developed to resolve the drawback of classical GA by employing fuzzy logic to control parameters and selective pressure of GA. The EFGA uses a Min-Heap data structure and Pareto principle to improve the classical genetic algorithm. The EFGA-CVBNN resolves the drawbacks of classical CVBNN by employing EFGA at the time of initial weight selection. From the simulation result, the GA-CVBNN performs better than existing CVBNN and it is not efficient. To enhance the performance of GA-CVBNN, we have developed EFGA-CVBNN. Experimental results on various synthetic datasets and benchmark datasets taken from UCI machine learning repository shows that EFGA-CVBNN outperforms PSO-CVBNN in terms of classification accuracy and time. Statistical t test has been used to validate the obtained results. [ABSTRACT FROM AUTHOR]

We wish to point out a mistake in the paper [Indian J Phys 90, 603 (2016)], which partially changes a few results presented. [ABSTRACT FROM AUTHOR]

This paper is focused on a finite-time reliable control design for nonlinear quadrotor attitude dynamic model against the actuator faults and external disturbances. By the utilization of an appropriate Lyapunov–Krasovskii functional, a finite-time performance analysis criterion is derived to obtain the robust reliable tracking control design for quadrotor dynamic model. Then, a fault-tolerant tracking control is designed such that the attitude of the quadrotor is reliable in the sense that it is finite-time bounded and satisfies the suggested mixed H ∞ and passivity performance index under given constraints. Also, the finite-time fault-tolerant controller gain is derived by solving the obtained linear matrix inequalities based on the convex optimization technique. Finally, simulation results are provided to verify the effectiveness and robustness of the proposed control design law. [ABSTRACT FROM AUTHOR]

In recent years, the usage of elliptic curve cryptography (ECC) in IoT applications is steadily increasing. The end nodes in IoT applications demand optimized device performance in terms of reduced power consumption and improved computing speed while not compromising on the security of the connected devices. ECC provides better security standards compared with many conventional cryptographic algorithms providing further scope to optimize the performance parameters. This work focuses on improving the key parameters like computing speed, area required for hardware implementation of ECC and demonstrates an efficient way of using the hardware resource sharing and scheduling mechanisms in elliptic curve group operations in affine coordinates which is crucial for implementation of scalar multiplication over prime field Fp. With the proposed scalar multiplication hardware architecture, we have achieved a good area-delay product and a significant reduction in cycle count when compared with other reported designs using the same affine coordinates. The proposed architecture has been implemented with 256 bits in both Xilinx Kintex-7 and Virtex-7 FPGA devices. The FPGA synthesis results show that a throughput of 68.52 kbps at a clock frequency of 124.2 MHz is achieved for F256 and the computation time is reduced around 1 ms without using any DSP slices. [ABSTRACT FROM AUTHOR]

This paper examines the synchronization problem of fractional-order complex dynamical networks (FCDNs) against input saturation and time-varying coupling by using a fault-tolerant control scheme. Precisely, the occurrence of coupling delay assumed is considered to be random, which is characterized by stochastic variables that obeys the Bernoulli distribution properties, and the actuator fault values are represented by a normally distributed stochastic random variable. The main aim of this paper is to propose the fault-tolerant fractional-order controller such that for given any initial condition, the state trajectories of considered FCDN are forced to synchronize asymptotically to the reference node. Based on the linear matrix inequality technique and Lyapunov stability theorem, a new set of sufficient conditions is established to not only guarantee mean-square asymptotic synchronization of the resulting closed-loop system but also cover the issues of actuator saturation and actuator faults. Moreover, the obtained sufficient conditions can help to enlarge the estimation about the domain of attraction for the closed-loop system. Finally, to show the advantages and effectiveness of the developed control design, numerical simulations are carried out on both Lorenz and Chen type FCDNs. [ABSTRACT FROM AUTHOR]

Advanced Encryption Standard (AES) is an effective cryptography algorithm for providing the better data communication since it guaranties high security. The Galois/Counter Mode (AES-GCM) has been integrated in various security constrained applications because it provides both authentication and confidentiality. AES algorithm helps to provide data confidentiality while authentication is provided by a universal GHASH function. Since most of existing GCM architectures concentrated on power and area reduction but an compact and efficient hardware architecture should also be considered. In this paper, high-performance architecture for GCM is proposed and its implementation is described. In order to achieve higher operating frequency and throughput, pipelined S-boxes are used in AES algorithm. For a GCM realization of AES, a high-speed, high-throughput, parallel architecture is proposed. Experimental results proves that the performance of the proposed work is around 17% higher than the existing architecture with 3 Gb/s throughput using TSMC 45-nm CMOS technology. [ABSTRACT FROM AUTHOR]

The objective of this paper is to establish the sufficient condition for the controllability of a control problem represented by second-order nonlinear differential equation with non-instantaneous impulses in a Hilbert space X. The results are obtained using the strongly continuous cosine family of linear operators and Banach fixed point method. Also, we study the controllability of the nonlocal as well as integro-differential systems. Finally, a few examples are provided to illustrate the applications of the obtained abstract results. [ABSTRACT FROM AUTHOR]

This paper investigates the disturbance rejection for a modified repetitive control system (MRCS) that is described by a class of linear singular systems in the presence of external disturbances and time-varying delay. In particular, an equivalent-input-disturbance (EID)-based estimator is included in the MRCS to compensate both periodic and aperiodic disturbances which yields an EID-based MRCS. More precisely, the incorporation of the EID-based estimator into the control input enables rejection of all types of disturbances in MRCS and tracking of a periodic reference input is archived via a repetitive controller. Attention is focused on the state-feedback repetitive controller design which not only guarantees the regular, impulse free, and asymptotic stability of the closed-loop singular MRCS, but also provides an optimized upper bound of the time-varying delay. Based on Lyapunov stability theory and utilizing some advanced mathematical techniques, a new set of delay-dependent sufficient conditions is presented in terms of linear matrix inequalities for obtaining the required result. Then, an explicit expression for the desired state-feedback repetitive control law is developed. Further, the obtained results are validated through two numerical examples in the simulation section. [ABSTRACT FROM AUTHOR]

This paper investigates the problem of finite-time sampled-data control for permanent magnet synchronous motor system (PMSMS) with input time-varying delay. First, a novel state space equation of PMSMS is obtained by choosing suitable state variables to the system attribute of PMSMS model. Then, based on the obtained state space model, the problem of finite-time sampled-data control design is addressed for uncertain PMSMS. By implementing a proper novel Lyapunov-Krasovskii functional together with linear matrix inequality optimization technique and Wirtinger-based integral inequality approach, a new set of delay-dependent sufficient condition is derived which guarantees the robust finite-time stability of the closed-loop PMSMS. Based on the obtained condition, an explicit expression for the desired controller can be established in terms of matrix inequalities. Finally, the effectiveness of developed control technique is validated via simulation results. [ABSTRACT FROM AUTHOR]

This paper addresses the passivity problem for a class of memristor-based bidirectional associate memory (BAM) neural networks with uncertain time-varying delays. In particular, the proposed memristive BAM neural networks is formulated with two different types of memductance functions. By constructing proper Lyapunov-Krasovskii functional and using differential inclusions theory, a new set of sufficient condition is obtained in terms of linear matrix inequalities which guarantee the passivity criteria for the considered neural networks. Finally, two numerical examples are given to illustrate the effectiveness of the proposed theoretical results. [ABSTRACT FROM AUTHOR]

This paper addresses the problem of robust $$L_2{-}L_\infty $$ control in delta domain for a class of Takagi-Sugeno (TS) fuzzy systems with interval time-varying delays and disturbance input. In particular, the system under study involves state time delay, uncertainties and fast sampling period $$\mathcal {T}$$ . The main aim of this work was to design a $$L_2{-}L_\infty $$ controller such that the proposed TS fuzzy system is robustly asymptotically stable with a $$L_2{-}L_\infty $$ prescribed performance level $$\gamma >0$$ . Based on the proper Lyapunov-Krasovskii functional (LKF) involving lower and upper bound of time delay and free-weighting technique, a new set of delay-dependent sufficient conditions in terms of linear matrix inequalities (LMIs) are established for obtaining the required result. The result reveals that the asymptotic stability is achieved quickly when the sampling frequency is high. Finally, a numerical example based on the truck-trailer model is given to demonstrate the effectiveness and potential of the proposed design technique. [ABSTRACT FROM AUTHOR]

In this paper, finite-time boundedness and dissipativity analysis for a class of networked cascade control systems (NCCSs) is investigated. The NCCS is defined with network-induced imperfections such as packet dropouts and time delays, and Bernoulli distributed white sequence is used to model a stochastic packet dropout case. Using the Lyapunov stability theory and linear matrix inequality (LMI) approach, we propose the sufficient conditions for finite-time boundedness and finite-time dissipativity of NCCS. Finally, the LMI-based conditions are applied on a practical power plant boiler-turbine system to show the effectiveness and applicability of the achieved results. [ABSTRACT FROM AUTHOR]

Rhopaloblaste augusta (Kurz) H. E. Moore is one of the threatened palm species endemic to Nicobar Islands. In order to know the distribution and conservation status of this palm, Maxent ecological niche modelling was used to predict the accurate distribution. The study revealed that high potential distribution of R. augusta was found in Great Nicobar and Car Nicobar islands; of the ten spatially unique points, six were from Great Nicobar, two from Camorta and one each from Katchall and Car Nicobar Islands. For islands like Tarassa, Chowra, Battimlav, Tinket and Nancowry, the model predicted significant influence of environmental variables in the distribution of species. High precipitation in warmest quarter, above 18 °C annual mean temperature and less temperature seasonality are the variables influencing distribution of this species. The islands of Nicobar group are rich in palm resources; however, habitats are extremely fragile owing to the prevalence of intense biotic and abiotic pressure. Urgent conservation initiatives are required to protect the existing endemic species richness of these islands. [ABSTRACT FROM AUTHOR]

The theoretical and numerical studies have been investigated on nonlinear propagation of weakly relativistic ion acoustic solitary waves in an unmagnetized plasma system consisting of nonextensive electrons, positrons and relativistic thermal ions. To study the characteristics of nonlinear propagation of the three-component plasma system, the reductive perturbation technique has been applied to derive the Korteweg-de Vries equation, which divulges the soliton-like solitary wave solution. The ansatz method is employed to carry out the integration of this equation. The effects of nonextensive electrons, positrons and relativistic thermal ions on phase velocity, amplitude and width of soliton and electrostatic nonlinear propagation of weakly relativistic ion acoustic solitary waves have been discussed taking different plasma parameters into consideration. The obtained results can be useful in understanding the features of small amplitude localized relativistic ion acoustic solitary waves in an unmagnetized three-component plasma system for hard thermal photon production with relativistic heavy ions collision in quark-gluon plasma as well as for astrophysical plasmas. [ABSTRACT FROM AUTHOR]

In this paper, the robust reliable $$H_\infty $$ control problem has been investigated for a class of nonlinear discrete-time TS fuzzy systems with random delay. In particular, the proposed fuzzy system consists of local nonlinear models with set of fuzzy rules, but the conventional TS fuzzy systems has local linear models. Our attention is focused on the design of a feedback reliable nonlinear retarded control law to ensure the robust asymptotic stability for nonlinear discrete-time TS fuzzy system with admissible uncertainties as well as actuator failure cases and random delay. In particular, by using an input delay approach, the random delay with stochastic parameters in the system matrices is introduced in the system model. Based on the Lyapunov approach, firstly, a sufficient condition for asymptotic stability is proposed for TS fuzzy systems in the presence of actuator failures. Then, a robust reliable $$H_\infty $$ control is designed for the uncertain TS fuzzy system by solving a strict linear matrix inequalities using the available numerical software. Finally, a numerical example based on real-time ball and beam system is provided to validate the effectiveness of the proposed design technique. [ABSTRACT FROM AUTHOR]

This paper is concerned with the problem of robust $$L_2-L_\infty $$ control for a class of uncertain systems with additive time-varying delays. Delay-dependent conditions are obtained for the analysis of robust asymptotic stability of uncertain closed-loop system with two additive time-varying delays using a novel Lyapunov-Krasovskii functional which includes information belonging to a given delay range. More precisely, a new set of sufficient conditions are derived in terms of linear matrix inequalities (LMIs) for achieving the required result of the closed-loop system with a prescribed $$L_2-L_\infty $$ disturbance attenuation level. In particular, Schur complement, Wirtinger's based inequality and convex combination technique are utilized to simplify the derivation in the main results. Further, the robust control law with guaranteed energy-to-peak $$L_2-L_\infty $$ performance is designed by solving a set of LMIs. Also, it is noticed that the advantage of the obtained criterion lies in its simplicity and less conservativeness. The proposed theoretical results have been compared through numerical simulation which reveals that the obtained criteria are considerably less conservative than some existing results. [ABSTRACT FROM AUTHOR]

In this paper, non-fragile observer-based $${\mathcal {H}}_{\infty }$$ controller design is investigated for a class of discrete-time systems. The system under consideration is assumed to have random fluctuations in both the state feedback controller gain and observer gain matrices. The random fluctuations are defined using Bernoulli-distributed white sequences with time-varying probability measures. The probability-dependent controller gains are designed to guarantee the stochastic stability of the system with a prescribed mixed $${\mathcal {H}}_{\infty }$$ and passivity performance. Lyapunov stability theory, passivity theory and a linear matrix inequality (LMI) approach are used to derive sufficient conditions for the existence of the state feedback controller and observer gains. The probability-dependent gain-scheduled controllers are designed based on a convex optimization problem using a set of LMIs, which can be easily solved with standard numerical packages. Finally, a practical application is presented as an example to illustrate the effectiveness and potential of the method. [ABSTRACT FROM AUTHOR]

This paper addresses the issue of observer-based control problem for a class of switched networked control systems (NCSs). In particular, by considering the packet loss and time delay in the network, a discrete-time switched system is formulated. Moreover, the packet loss in the network is assumed to occur in a random way, which is described by introducing Bernoulli distributed white sequences. First, results for the exponential stabilization of discrete-time switched NCSs without random packet loss is derived by using the average dwell time approach and multiple Lyapunov-Krasovskii function. Next, the attention is focused on designing an observer-based state feedback controller for NCSs with random packet loss which ensures that the resulting error system is exponentially stable. Further, the sufficient conditions for existence of control parameters are formulated in the form of linear matrix inequalities (LMIs) which can be easily solved by using some standard numerical packages. Also, the observer and control gains can be calculated by using the solutions of a set of LMIs. Finally, a numerical example based on DC motor model is provided to illustrate the applicability and effectiveness of the proposed design procedure. [ABSTRACT FROM AUTHOR]

We study a class of non-densely defined impulsive neutral stochastic functional differential equations driven by an independent cylindrical fractional Brownian motion (fBm) with Hurst parameter H ∈ (1/2, 1) in the Hilbert space. We prove the existence and uniqueness of the integral solution for this kind of equations with the coefficients satisfying some non-Lipschitz conditions. The results are obtained by using the method of successive approximation. [ABSTRACT FROM AUTHOR]

In this paper, fault-tolerant sampled-data control for flexible spacecraft in the presence of external disturbances, partial actuator failures and probabilistic time delays is investigated. In particular, unlike the common assumptions on continuous-time information on control input, a more realistic sampled-data communication strategy is proposed with probabilistic occurrence of time-varying delays which is modeled by introducing Bernoulli distributed sequences. The main purpose of this paper is to derive fault-tolerant sampled-data control law which makes the closed-loop system robustly asymptotically stable with a prescribed upper bound of the cost function about its equilibrium point for all possible actuator failures. More precisely, by constructing an appropriate Lyapunov-Krasovskii functional involving the lower and upper bound of the probabilistic time delay, a new set of sufficient conditions are derived in terms of linear matrix inequalities for achieving the required result. Numerical simulations are presented by taking the real parameters to the considered aircraft model, which is not only highlighting the ensured closed-loop performance by the proposed control law, but also illustrates its superior fault tolerance, fast convergence and robustness in the presence of external disturbances and actuator faults when compared with the conventional controller. The simulation result reveals the effectiveness and potential of the proposed new design techniques. [ABSTRACT FROM AUTHOR]

In this article, we consider the robust reliable sample-data control problem for an offshore steel jacket platform with input time-varying delay and possible occurrence of actuator faults subject to nonlinear self-exited hydrodynamic forces. The main objective of this work is to design a state feedback reliable sample-data controller such that for all admissible uncertainties as well as actuator failure cases, the resulting closed-loop system is robustly exponentially stable. By constructing an appropriate Lyapunov-Krasovskii functional and using linear matrix inequality (LMI) approach, a new set of sufficient condition is derived in terms of LMIs for the existence of robust reliable sample-data control law. In particular, the uncertainty under consideration in system parameters includes linear fractional norm-bounded uncertainty. Further, Schur complement and Jenson's integral inequality are used to substantially simplify the derivation in the main results. More precisely, the controller gain matrix for the nonlinear offshore steel jacket platform can be achieved by solving the LMIs, which can be easily facilitated by using some standard numerical packages. Finally, a numerical example with simulation result is provided to illustrate the applicability and effectiveness of the proposed reliable sampled-data control scheme. [ABSTRACT FROM AUTHOR]

The need for real time high end digital signal/image processing demands a very huge computation with a reasonable accuracy. This paper presents two energy efficient low area error tolerant adders (ELAETA-I and ELAETA-II) which could cater the needs of most signal processing application. This work has reduced the tradeoff that exists between the amount of computation and the accuracy. The error sensitive block in the inaccurate part of the ELAETA circuit, predetermines the carry and allows the simultaneous calculation of inaccurate part sum value, thereby reducing the maximum delay by 55 % compared to error-tolerant adder (ETA-I) and its appropriate addition of carry to the accurate part increases the accuracy by 20 % over the existing ETA-I and ETA-II. The inaccurate part of the adder is being constructed with the proposed new OR gate cell and the pass transistor cell, which has reduced the number of transistor by 10 and 12, respectively, compared with the existing ETA-I. In addition a new data aware block has been included which will evaluate the input sequence and appropriately activate/de-activate certain computation modules and there by reduce the switching activity. The simulation result of the proposed ELAETA circuits shows that the power delay product has reduced by 59 % and area around 20 %. The whole circuit has been constructed using Cadence Virtuoso and the simulation done using Spectre with 180 and 45 nm technology node from TSMC. [ABSTRACT FROM AUTHOR]

In this paper, we investigate the problem of robust state estimator design for a class of uncertain discrete-time genetic regulatory networks (GRNs) with time varying delays and randomly occurring uncertainties. By introducing a new discretized Lyapunov–Krasovskii functional together with a free-weighting matrix technique, first we derive a set of sufficient conditions for the existence of global asymptotic state estimator for the discrete-time GRN model with time delays satisfying both the lower and the upper bound of the interval time-varying delay. Further, the obtained results are extended to deal the robust state estimator design for the discrete-time GRN model in the presence of randomly occurring uncertainties which obey certain mutually uncorrelated Bernoulli distributed white noise sequences. The proposed criterions are established in terms of linear matrix inequalities (LMIs) which can be easily solved via Matlab LMI toolbox. Finally, the robust state estimator design has been implemented in a gene network model to illustrate the applicability and usefulness of the obtained theory. [ABSTRACT FROM AUTHOR]